mirror of
https://github.com/c64scene-ar/llvm-6502.git
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fabd32deb0
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43160 91177308-0d34-0410-b5e6-96231b3b80d8
5004 lines
189 KiB
C++
5004 lines
189 KiB
C++
//===-- DAGCombiner.cpp - Implement a DAG node combiner -------------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file was developed by Nate Begeman and is distributed under the
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// University of Illinois Open Source License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This pass combines dag nodes to form fewer, simpler DAG nodes. It can be run
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// both before and after the DAG is legalized.
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//
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// FIXME: Missing folds
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// sdiv, udiv, srem, urem (X, const) where X is an integer can be expanded into
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// a sequence of multiplies, shifts, and adds. This should be controlled by
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// some kind of hint from the target that int div is expensive.
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// various folds of mulh[s,u] by constants such as -1, powers of 2, etc.
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//
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// FIXME: select C, pow2, pow2 -> something smart
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// FIXME: trunc(select X, Y, Z) -> select X, trunc(Y), trunc(Z)
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// FIXME: Dead stores -> nuke
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// FIXME: shr X, (and Y,31) -> shr X, Y (TRICKY!)
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// FIXME: mul (x, const) -> shifts + adds
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// FIXME: undef values
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// FIXME: divide by zero is currently left unfolded. do we want to turn this
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// into an undef?
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// FIXME: select ne (select cc, 1, 0), 0, true, false -> select cc, true, false
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//
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//===----------------------------------------------------------------------===//
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#define DEBUG_TYPE "dagcombine"
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#include "llvm/CodeGen/SelectionDAG.h"
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#include "llvm/Analysis/AliasAnalysis.h"
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#include "llvm/Target/TargetData.h"
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#include "llvm/Target/TargetLowering.h"
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#include "llvm/Target/TargetMachine.h"
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#include "llvm/Target/TargetOptions.h"
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#include "llvm/ADT/SmallPtrSet.h"
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#include "llvm/ADT/Statistic.h"
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#include "llvm/Support/Compiler.h"
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#include "llvm/Support/CommandLine.h"
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#include "llvm/Support/Debug.h"
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#include "llvm/Support/MathExtras.h"
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#include <algorithm>
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using namespace llvm;
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STATISTIC(NodesCombined , "Number of dag nodes combined");
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STATISTIC(PreIndexedNodes , "Number of pre-indexed nodes created");
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STATISTIC(PostIndexedNodes, "Number of post-indexed nodes created");
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namespace {
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#ifndef NDEBUG
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static cl::opt<bool>
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ViewDAGCombine1("view-dag-combine1-dags", cl::Hidden,
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cl::desc("Pop up a window to show dags before the first "
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"dag combine pass"));
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static cl::opt<bool>
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ViewDAGCombine2("view-dag-combine2-dags", cl::Hidden,
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cl::desc("Pop up a window to show dags before the second "
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"dag combine pass"));
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#else
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static const bool ViewDAGCombine1 = false;
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static const bool ViewDAGCombine2 = false;
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#endif
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static cl::opt<bool>
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CombinerAA("combiner-alias-analysis", cl::Hidden,
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cl::desc("Turn on alias analysis during testing"));
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static cl::opt<bool>
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CombinerGlobalAA("combiner-global-alias-analysis", cl::Hidden,
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cl::desc("Include global information in alias analysis"));
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//------------------------------ DAGCombiner ---------------------------------//
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class VISIBILITY_HIDDEN DAGCombiner {
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SelectionDAG &DAG;
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TargetLowering &TLI;
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bool AfterLegalize;
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// Worklist of all of the nodes that need to be simplified.
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std::vector<SDNode*> WorkList;
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// AA - Used for DAG load/store alias analysis.
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AliasAnalysis &AA;
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/// AddUsersToWorkList - When an instruction is simplified, add all users of
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/// the instruction to the work lists because they might get more simplified
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/// now.
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///
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void AddUsersToWorkList(SDNode *N) {
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for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end();
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UI != UE; ++UI)
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AddToWorkList(*UI);
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}
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/// removeFromWorkList - remove all instances of N from the worklist.
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///
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void removeFromWorkList(SDNode *N) {
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WorkList.erase(std::remove(WorkList.begin(), WorkList.end(), N),
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WorkList.end());
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}
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/// visit - call the node-specific routine that knows how to fold each
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/// particular type of node.
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SDOperand visit(SDNode *N);
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public:
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/// AddToWorkList - Add to the work list making sure it's instance is at the
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/// the back (next to be processed.)
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void AddToWorkList(SDNode *N) {
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removeFromWorkList(N);
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WorkList.push_back(N);
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}
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SDOperand CombineTo(SDNode *N, const SDOperand *To, unsigned NumTo,
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bool AddTo = true) {
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assert(N->getNumValues() == NumTo && "Broken CombineTo call!");
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++NodesCombined;
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DOUT << "\nReplacing.1 "; DEBUG(N->dump(&DAG));
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DOUT << "\nWith: "; DEBUG(To[0].Val->dump(&DAG));
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DOUT << " and " << NumTo-1 << " other values\n";
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std::vector<SDNode*> NowDead;
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DAG.ReplaceAllUsesWith(N, To, &NowDead);
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if (AddTo) {
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// Push the new nodes and any users onto the worklist
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for (unsigned i = 0, e = NumTo; i != e; ++i) {
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AddToWorkList(To[i].Val);
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AddUsersToWorkList(To[i].Val);
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}
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}
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// Nodes can be reintroduced into the worklist. Make sure we do not
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// process a node that has been replaced.
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removeFromWorkList(N);
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for (unsigned i = 0, e = NowDead.size(); i != e; ++i)
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removeFromWorkList(NowDead[i]);
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// Finally, since the node is now dead, remove it from the graph.
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DAG.DeleteNode(N);
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return SDOperand(N, 0);
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}
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SDOperand CombineTo(SDNode *N, SDOperand Res, bool AddTo = true) {
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return CombineTo(N, &Res, 1, AddTo);
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}
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SDOperand CombineTo(SDNode *N, SDOperand Res0, SDOperand Res1,
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bool AddTo = true) {
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SDOperand To[] = { Res0, Res1 };
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return CombineTo(N, To, 2, AddTo);
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}
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private:
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/// SimplifyDemandedBits - Check the specified integer node value to see if
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/// it can be simplified or if things it uses can be simplified by bit
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/// propagation. If so, return true.
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bool SimplifyDemandedBits(SDOperand Op, uint64_t Demanded = ~0ULL) {
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TargetLowering::TargetLoweringOpt TLO(DAG);
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uint64_t KnownZero, KnownOne;
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Demanded &= MVT::getIntVTBitMask(Op.getValueType());
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if (!TLI.SimplifyDemandedBits(Op, Demanded, KnownZero, KnownOne, TLO))
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return false;
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// Revisit the node.
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AddToWorkList(Op.Val);
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// Replace the old value with the new one.
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++NodesCombined;
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DOUT << "\nReplacing.2 "; DEBUG(TLO.Old.Val->dump(&DAG));
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DOUT << "\nWith: "; DEBUG(TLO.New.Val->dump(&DAG));
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DOUT << '\n';
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std::vector<SDNode*> NowDead;
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DAG.ReplaceAllUsesOfValueWith(TLO.Old, TLO.New, &NowDead);
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// Push the new node and any (possibly new) users onto the worklist.
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AddToWorkList(TLO.New.Val);
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AddUsersToWorkList(TLO.New.Val);
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// Nodes can end up on the worklist more than once. Make sure we do
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// not process a node that has been replaced.
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for (unsigned i = 0, e = NowDead.size(); i != e; ++i)
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removeFromWorkList(NowDead[i]);
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// Finally, if the node is now dead, remove it from the graph. The node
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// may not be dead if the replacement process recursively simplified to
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// something else needing this node.
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if (TLO.Old.Val->use_empty()) {
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removeFromWorkList(TLO.Old.Val);
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// If the operands of this node are only used by the node, they will now
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// be dead. Make sure to visit them first to delete dead nodes early.
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for (unsigned i = 0, e = TLO.Old.Val->getNumOperands(); i != e; ++i)
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if (TLO.Old.Val->getOperand(i).Val->hasOneUse())
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AddToWorkList(TLO.Old.Val->getOperand(i).Val);
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DAG.DeleteNode(TLO.Old.Val);
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}
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return true;
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}
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bool CombineToPreIndexedLoadStore(SDNode *N);
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bool CombineToPostIndexedLoadStore(SDNode *N);
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/// combine - call the node-specific routine that knows how to fold each
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/// particular type of node. If that doesn't do anything, try the
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/// target-specific DAG combines.
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SDOperand combine(SDNode *N);
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// Visitation implementation - Implement dag node combining for different
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// node types. The semantics are as follows:
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// Return Value:
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// SDOperand.Val == 0 - No change was made
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// SDOperand.Val == N - N was replaced, is dead, and is already handled.
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// otherwise - N should be replaced by the returned Operand.
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//
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SDOperand visitTokenFactor(SDNode *N);
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SDOperand visitADD(SDNode *N);
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SDOperand visitSUB(SDNode *N);
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SDOperand visitADDC(SDNode *N);
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SDOperand visitADDE(SDNode *N);
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SDOperand visitMUL(SDNode *N);
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SDOperand visitSDIV(SDNode *N);
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SDOperand visitUDIV(SDNode *N);
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SDOperand visitSREM(SDNode *N);
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SDOperand visitUREM(SDNode *N);
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SDOperand visitMULHU(SDNode *N);
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SDOperand visitMULHS(SDNode *N);
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SDOperand visitSMUL_LOHI(SDNode *N);
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SDOperand visitUMUL_LOHI(SDNode *N);
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SDOperand visitSDIVREM(SDNode *N);
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SDOperand visitUDIVREM(SDNode *N);
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SDOperand visitAND(SDNode *N);
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SDOperand visitOR(SDNode *N);
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SDOperand visitXOR(SDNode *N);
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SDOperand SimplifyVBinOp(SDNode *N);
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SDOperand visitSHL(SDNode *N);
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SDOperand visitSRA(SDNode *N);
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SDOperand visitSRL(SDNode *N);
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SDOperand visitCTLZ(SDNode *N);
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SDOperand visitCTTZ(SDNode *N);
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SDOperand visitCTPOP(SDNode *N);
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SDOperand visitSELECT(SDNode *N);
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SDOperand visitSELECT_CC(SDNode *N);
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SDOperand visitSETCC(SDNode *N);
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SDOperand visitSIGN_EXTEND(SDNode *N);
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SDOperand visitZERO_EXTEND(SDNode *N);
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SDOperand visitANY_EXTEND(SDNode *N);
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SDOperand visitSIGN_EXTEND_INREG(SDNode *N);
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SDOperand visitTRUNCATE(SDNode *N);
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SDOperand visitBIT_CONVERT(SDNode *N);
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SDOperand visitFADD(SDNode *N);
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SDOperand visitFSUB(SDNode *N);
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SDOperand visitFMUL(SDNode *N);
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SDOperand visitFDIV(SDNode *N);
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SDOperand visitFREM(SDNode *N);
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SDOperand visitFCOPYSIGN(SDNode *N);
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SDOperand visitSINT_TO_FP(SDNode *N);
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SDOperand visitUINT_TO_FP(SDNode *N);
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SDOperand visitFP_TO_SINT(SDNode *N);
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SDOperand visitFP_TO_UINT(SDNode *N);
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SDOperand visitFP_ROUND(SDNode *N);
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SDOperand visitFP_ROUND_INREG(SDNode *N);
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SDOperand visitFP_EXTEND(SDNode *N);
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SDOperand visitFNEG(SDNode *N);
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SDOperand visitFABS(SDNode *N);
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SDOperand visitBRCOND(SDNode *N);
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SDOperand visitBR_CC(SDNode *N);
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SDOperand visitLOAD(SDNode *N);
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SDOperand visitSTORE(SDNode *N);
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SDOperand visitINSERT_VECTOR_ELT(SDNode *N);
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SDOperand visitEXTRACT_VECTOR_ELT(SDNode *N);
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SDOperand visitBUILD_VECTOR(SDNode *N);
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SDOperand visitCONCAT_VECTORS(SDNode *N);
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SDOperand visitVECTOR_SHUFFLE(SDNode *N);
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SDOperand XformToShuffleWithZero(SDNode *N);
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SDOperand ReassociateOps(unsigned Opc, SDOperand LHS, SDOperand RHS);
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bool SimplifySelectOps(SDNode *SELECT, SDOperand LHS, SDOperand RHS);
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SDOperand SimplifyBinOpWithSameOpcodeHands(SDNode *N);
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SDOperand SimplifySelect(SDOperand N0, SDOperand N1, SDOperand N2);
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SDOperand SimplifySelectCC(SDOperand N0, SDOperand N1, SDOperand N2,
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SDOperand N3, ISD::CondCode CC,
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bool NotExtCompare = false);
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SDOperand SimplifySetCC(MVT::ValueType VT, SDOperand N0, SDOperand N1,
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ISD::CondCode Cond, bool foldBooleans = true);
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bool SimplifyNodeWithTwoResults(SDNode *N, unsigned LoOp, unsigned HiOp);
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SDOperand ConstantFoldBIT_CONVERTofBUILD_VECTOR(SDNode *, MVT::ValueType);
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SDOperand BuildSDIV(SDNode *N);
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SDOperand BuildUDIV(SDNode *N);
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SDNode *MatchRotate(SDOperand LHS, SDOperand RHS);
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SDOperand ReduceLoadWidth(SDNode *N);
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SDOperand GetDemandedBits(SDOperand V, uint64_t Mask);
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/// GatherAllAliases - Walk up chain skipping non-aliasing memory nodes,
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/// looking for aliasing nodes and adding them to the Aliases vector.
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void GatherAllAliases(SDNode *N, SDOperand OriginalChain,
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SmallVector<SDOperand, 8> &Aliases);
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/// isAlias - Return true if there is any possibility that the two addresses
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/// overlap.
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bool isAlias(SDOperand Ptr1, int64_t Size1,
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const Value *SrcValue1, int SrcValueOffset1,
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SDOperand Ptr2, int64_t Size2,
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const Value *SrcValue2, int SrcValueOffset2);
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/// FindAliasInfo - Extracts the relevant alias information from the memory
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/// node. Returns true if the operand was a load.
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bool FindAliasInfo(SDNode *N,
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SDOperand &Ptr, int64_t &Size,
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const Value *&SrcValue, int &SrcValueOffset);
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/// FindBetterChain - Walk up chain skipping non-aliasing memory nodes,
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/// looking for a better chain (aliasing node.)
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SDOperand FindBetterChain(SDNode *N, SDOperand Chain);
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public:
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DAGCombiner(SelectionDAG &D, AliasAnalysis &A)
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: DAG(D),
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TLI(D.getTargetLoweringInfo()),
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AfterLegalize(false),
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AA(A) {}
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/// Run - runs the dag combiner on all nodes in the work list
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void Run(bool RunningAfterLegalize);
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};
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}
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//===----------------------------------------------------------------------===//
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// TargetLowering::DAGCombinerInfo implementation
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//===----------------------------------------------------------------------===//
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void TargetLowering::DAGCombinerInfo::AddToWorklist(SDNode *N) {
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((DAGCombiner*)DC)->AddToWorkList(N);
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}
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SDOperand TargetLowering::DAGCombinerInfo::
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CombineTo(SDNode *N, const std::vector<SDOperand> &To) {
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return ((DAGCombiner*)DC)->CombineTo(N, &To[0], To.size());
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}
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SDOperand TargetLowering::DAGCombinerInfo::
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CombineTo(SDNode *N, SDOperand Res) {
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return ((DAGCombiner*)DC)->CombineTo(N, Res);
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}
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SDOperand TargetLowering::DAGCombinerInfo::
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CombineTo(SDNode *N, SDOperand Res0, SDOperand Res1) {
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return ((DAGCombiner*)DC)->CombineTo(N, Res0, Res1);
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}
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//===----------------------------------------------------------------------===//
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// Helper Functions
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//===----------------------------------------------------------------------===//
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/// isNegatibleForFree - Return 1 if we can compute the negated form of the
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/// specified expression for the same cost as the expression itself, or 2 if we
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/// can compute the negated form more cheaply than the expression itself.
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static char isNegatibleForFree(SDOperand Op, unsigned Depth = 0) {
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// No compile time optimizations on this type.
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if (Op.getValueType() == MVT::ppcf128)
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return 0;
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// fneg is removable even if it has multiple uses.
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if (Op.getOpcode() == ISD::FNEG) return 2;
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// Don't allow anything with multiple uses.
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if (!Op.hasOneUse()) return 0;
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// Don't recurse exponentially.
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if (Depth > 6) return 0;
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switch (Op.getOpcode()) {
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default: return false;
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case ISD::ConstantFP:
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return 1;
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case ISD::FADD:
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// FIXME: determine better conditions for this xform.
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if (!UnsafeFPMath) return 0;
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// -(A+B) -> -A - B
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if (char V = isNegatibleForFree(Op.getOperand(0), Depth+1))
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return V;
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// -(A+B) -> -B - A
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return isNegatibleForFree(Op.getOperand(1), Depth+1);
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case ISD::FSUB:
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// We can't turn -(A-B) into B-A when we honor signed zeros.
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if (!UnsafeFPMath) return 0;
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// -(A-B) -> B-A
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return 1;
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case ISD::FMUL:
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case ISD::FDIV:
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if (HonorSignDependentRoundingFPMath()) return 0;
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// -(X*Y) -> (-X * Y) or (X*-Y)
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if (char V = isNegatibleForFree(Op.getOperand(0), Depth+1))
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return V;
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return isNegatibleForFree(Op.getOperand(1), Depth+1);
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case ISD::FP_EXTEND:
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case ISD::FP_ROUND:
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case ISD::FSIN:
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return isNegatibleForFree(Op.getOperand(0), Depth+1);
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}
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}
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/// GetNegatedExpression - If isNegatibleForFree returns true, this function
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/// returns the newly negated expression.
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static SDOperand GetNegatedExpression(SDOperand Op, SelectionDAG &DAG,
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unsigned Depth = 0) {
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// fneg is removable even if it has multiple uses.
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if (Op.getOpcode() == ISD::FNEG) return Op.getOperand(0);
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// Don't allow anything with multiple uses.
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assert(Op.hasOneUse() && "Unknown reuse!");
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assert(Depth <= 6 && "GetNegatedExpression doesn't match isNegatibleForFree");
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switch (Op.getOpcode()) {
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default: assert(0 && "Unknown code");
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case ISD::ConstantFP: {
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APFloat V = cast<ConstantFPSDNode>(Op)->getValueAPF();
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V.changeSign();
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return DAG.getConstantFP(V, Op.getValueType());
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}
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case ISD::FADD:
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// FIXME: determine better conditions for this xform.
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assert(UnsafeFPMath);
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// -(A+B) -> -A - B
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if (isNegatibleForFree(Op.getOperand(0), Depth+1))
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return DAG.getNode(ISD::FSUB, Op.getValueType(),
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GetNegatedExpression(Op.getOperand(0), DAG, Depth+1),
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Op.getOperand(1));
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// -(A+B) -> -B - A
|
|
return DAG.getNode(ISD::FSUB, Op.getValueType(),
|
|
GetNegatedExpression(Op.getOperand(1), DAG, Depth+1),
|
|
Op.getOperand(0));
|
|
case ISD::FSUB:
|
|
// We can't turn -(A-B) into B-A when we honor signed zeros.
|
|
assert(UnsafeFPMath);
|
|
|
|
// -(0-B) -> B
|
|
if (ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(Op.getOperand(0)))
|
|
if (N0CFP->getValueAPF().isZero())
|
|
return Op.getOperand(1);
|
|
|
|
// -(A-B) -> B-A
|
|
return DAG.getNode(ISD::FSUB, Op.getValueType(), Op.getOperand(1),
|
|
Op.getOperand(0));
|
|
|
|
case ISD::FMUL:
|
|
case ISD::FDIV:
|
|
assert(!HonorSignDependentRoundingFPMath());
|
|
|
|
// -(X*Y) -> -X * Y
|
|
if (isNegatibleForFree(Op.getOperand(0), Depth+1))
|
|
return DAG.getNode(Op.getOpcode(), Op.getValueType(),
|
|
GetNegatedExpression(Op.getOperand(0), DAG, Depth+1),
|
|
Op.getOperand(1));
|
|
|
|
// -(X*Y) -> X * -Y
|
|
return DAG.getNode(Op.getOpcode(), Op.getValueType(),
|
|
Op.getOperand(0),
|
|
GetNegatedExpression(Op.getOperand(1), DAG, Depth+1));
|
|
|
|
case ISD::FP_EXTEND:
|
|
case ISD::FP_ROUND:
|
|
case ISD::FSIN:
|
|
return DAG.getNode(Op.getOpcode(), Op.getValueType(),
|
|
GetNegatedExpression(Op.getOperand(0), DAG, Depth+1));
|
|
}
|
|
}
|
|
|
|
|
|
// isSetCCEquivalent - Return true if this node is a setcc, or is a select_cc
|
|
// that selects between the values 1 and 0, making it equivalent to a setcc.
|
|
// Also, set the incoming LHS, RHS, and CC references to the appropriate
|
|
// nodes based on the type of node we are checking. This simplifies life a
|
|
// bit for the callers.
|
|
static bool isSetCCEquivalent(SDOperand N, SDOperand &LHS, SDOperand &RHS,
|
|
SDOperand &CC) {
|
|
if (N.getOpcode() == ISD::SETCC) {
|
|
LHS = N.getOperand(0);
|
|
RHS = N.getOperand(1);
|
|
CC = N.getOperand(2);
|
|
return true;
|
|
}
|
|
if (N.getOpcode() == ISD::SELECT_CC &&
|
|
N.getOperand(2).getOpcode() == ISD::Constant &&
|
|
N.getOperand(3).getOpcode() == ISD::Constant &&
|
|
cast<ConstantSDNode>(N.getOperand(2))->getValue() == 1 &&
|
|
cast<ConstantSDNode>(N.getOperand(3))->isNullValue()) {
|
|
LHS = N.getOperand(0);
|
|
RHS = N.getOperand(1);
|
|
CC = N.getOperand(4);
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
// isOneUseSetCC - Return true if this is a SetCC-equivalent operation with only
|
|
// one use. If this is true, it allows the users to invert the operation for
|
|
// free when it is profitable to do so.
|
|
static bool isOneUseSetCC(SDOperand N) {
|
|
SDOperand N0, N1, N2;
|
|
if (isSetCCEquivalent(N, N0, N1, N2) && N.Val->hasOneUse())
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
SDOperand DAGCombiner::ReassociateOps(unsigned Opc, SDOperand N0, SDOperand N1){
|
|
MVT::ValueType VT = N0.getValueType();
|
|
// reassoc. (op (op x, c1), y) -> (op (op x, y), c1) iff x+c1 has one use
|
|
// reassoc. (op (op x, c1), c2) -> (op x, (op c1, c2))
|
|
if (N0.getOpcode() == Opc && isa<ConstantSDNode>(N0.getOperand(1))) {
|
|
if (isa<ConstantSDNode>(N1)) {
|
|
SDOperand OpNode = DAG.getNode(Opc, VT, N0.getOperand(1), N1);
|
|
AddToWorkList(OpNode.Val);
|
|
return DAG.getNode(Opc, VT, OpNode, N0.getOperand(0));
|
|
} else if (N0.hasOneUse()) {
|
|
SDOperand OpNode = DAG.getNode(Opc, VT, N0.getOperand(0), N1);
|
|
AddToWorkList(OpNode.Val);
|
|
return DAG.getNode(Opc, VT, OpNode, N0.getOperand(1));
|
|
}
|
|
}
|
|
// reassoc. (op y, (op x, c1)) -> (op (op x, y), c1) iff x+c1 has one use
|
|
// reassoc. (op c2, (op x, c1)) -> (op x, (op c1, c2))
|
|
if (N1.getOpcode() == Opc && isa<ConstantSDNode>(N1.getOperand(1))) {
|
|
if (isa<ConstantSDNode>(N0)) {
|
|
SDOperand OpNode = DAG.getNode(Opc, VT, N1.getOperand(1), N0);
|
|
AddToWorkList(OpNode.Val);
|
|
return DAG.getNode(Opc, VT, OpNode, N1.getOperand(0));
|
|
} else if (N1.hasOneUse()) {
|
|
SDOperand OpNode = DAG.getNode(Opc, VT, N1.getOperand(0), N0);
|
|
AddToWorkList(OpNode.Val);
|
|
return DAG.getNode(Opc, VT, OpNode, N1.getOperand(1));
|
|
}
|
|
}
|
|
return SDOperand();
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Main DAG Combiner implementation
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
void DAGCombiner::Run(bool RunningAfterLegalize) {
|
|
// set the instance variable, so that the various visit routines may use it.
|
|
AfterLegalize = RunningAfterLegalize;
|
|
|
|
// Add all the dag nodes to the worklist.
|
|
for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(),
|
|
E = DAG.allnodes_end(); I != E; ++I)
|
|
WorkList.push_back(I);
|
|
|
|
// Create a dummy node (which is not added to allnodes), that adds a reference
|
|
// to the root node, preventing it from being deleted, and tracking any
|
|
// changes of the root.
|
|
HandleSDNode Dummy(DAG.getRoot());
|
|
|
|
// The root of the dag may dangle to deleted nodes until the dag combiner is
|
|
// done. Set it to null to avoid confusion.
|
|
DAG.setRoot(SDOperand());
|
|
|
|
// while the worklist isn't empty, inspect the node on the end of it and
|
|
// try and combine it.
|
|
while (!WorkList.empty()) {
|
|
SDNode *N = WorkList.back();
|
|
WorkList.pop_back();
|
|
|
|
// If N has no uses, it is dead. Make sure to revisit all N's operands once
|
|
// N is deleted from the DAG, since they too may now be dead or may have a
|
|
// reduced number of uses, allowing other xforms.
|
|
if (N->use_empty() && N != &Dummy) {
|
|
for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
|
|
AddToWorkList(N->getOperand(i).Val);
|
|
|
|
DAG.DeleteNode(N);
|
|
continue;
|
|
}
|
|
|
|
SDOperand RV = combine(N);
|
|
|
|
if (RV.Val) {
|
|
++NodesCombined;
|
|
// If we get back the same node we passed in, rather than a new node or
|
|
// zero, we know that the node must have defined multiple values and
|
|
// CombineTo was used. Since CombineTo takes care of the worklist
|
|
// mechanics for us, we have no work to do in this case.
|
|
if (RV.Val != N) {
|
|
assert(N->getOpcode() != ISD::DELETED_NODE &&
|
|
RV.Val->getOpcode() != ISD::DELETED_NODE &&
|
|
"Node was deleted but visit returned new node!");
|
|
|
|
DOUT << "\nReplacing.3 "; DEBUG(N->dump(&DAG));
|
|
DOUT << "\nWith: "; DEBUG(RV.Val->dump(&DAG));
|
|
DOUT << '\n';
|
|
std::vector<SDNode*> NowDead;
|
|
if (N->getNumValues() == RV.Val->getNumValues())
|
|
DAG.ReplaceAllUsesWith(N, RV.Val, &NowDead);
|
|
else {
|
|
assert(N->getValueType(0) == RV.getValueType() && "Type mismatch");
|
|
SDOperand OpV = RV;
|
|
DAG.ReplaceAllUsesWith(N, &OpV, &NowDead);
|
|
}
|
|
|
|
// Push the new node and any users onto the worklist
|
|
AddToWorkList(RV.Val);
|
|
AddUsersToWorkList(RV.Val);
|
|
|
|
// Nodes can be reintroduced into the worklist. Make sure we do not
|
|
// process a node that has been replaced.
|
|
removeFromWorkList(N);
|
|
for (unsigned i = 0, e = NowDead.size(); i != e; ++i)
|
|
removeFromWorkList(NowDead[i]);
|
|
|
|
// Finally, since the node is now dead, remove it from the graph.
|
|
DAG.DeleteNode(N);
|
|
}
|
|
}
|
|
}
|
|
|
|
// If the root changed (e.g. it was a dead load, update the root).
|
|
DAG.setRoot(Dummy.getValue());
|
|
}
|
|
|
|
SDOperand DAGCombiner::visit(SDNode *N) {
|
|
switch(N->getOpcode()) {
|
|
default: break;
|
|
case ISD::TokenFactor: return visitTokenFactor(N);
|
|
case ISD::ADD: return visitADD(N);
|
|
case ISD::SUB: return visitSUB(N);
|
|
case ISD::ADDC: return visitADDC(N);
|
|
case ISD::ADDE: return visitADDE(N);
|
|
case ISD::MUL: return visitMUL(N);
|
|
case ISD::SDIV: return visitSDIV(N);
|
|
case ISD::UDIV: return visitUDIV(N);
|
|
case ISD::SREM: return visitSREM(N);
|
|
case ISD::UREM: return visitUREM(N);
|
|
case ISD::MULHU: return visitMULHU(N);
|
|
case ISD::MULHS: return visitMULHS(N);
|
|
case ISD::SMUL_LOHI: return visitSMUL_LOHI(N);
|
|
case ISD::UMUL_LOHI: return visitUMUL_LOHI(N);
|
|
case ISD::SDIVREM: return visitSDIVREM(N);
|
|
case ISD::UDIVREM: return visitUDIVREM(N);
|
|
case ISD::AND: return visitAND(N);
|
|
case ISD::OR: return visitOR(N);
|
|
case ISD::XOR: return visitXOR(N);
|
|
case ISD::SHL: return visitSHL(N);
|
|
case ISD::SRA: return visitSRA(N);
|
|
case ISD::SRL: return visitSRL(N);
|
|
case ISD::CTLZ: return visitCTLZ(N);
|
|
case ISD::CTTZ: return visitCTTZ(N);
|
|
case ISD::CTPOP: return visitCTPOP(N);
|
|
case ISD::SELECT: return visitSELECT(N);
|
|
case ISD::SELECT_CC: return visitSELECT_CC(N);
|
|
case ISD::SETCC: return visitSETCC(N);
|
|
case ISD::SIGN_EXTEND: return visitSIGN_EXTEND(N);
|
|
case ISD::ZERO_EXTEND: return visitZERO_EXTEND(N);
|
|
case ISD::ANY_EXTEND: return visitANY_EXTEND(N);
|
|
case ISD::SIGN_EXTEND_INREG: return visitSIGN_EXTEND_INREG(N);
|
|
case ISD::TRUNCATE: return visitTRUNCATE(N);
|
|
case ISD::BIT_CONVERT: return visitBIT_CONVERT(N);
|
|
case ISD::FADD: return visitFADD(N);
|
|
case ISD::FSUB: return visitFSUB(N);
|
|
case ISD::FMUL: return visitFMUL(N);
|
|
case ISD::FDIV: return visitFDIV(N);
|
|
case ISD::FREM: return visitFREM(N);
|
|
case ISD::FCOPYSIGN: return visitFCOPYSIGN(N);
|
|
case ISD::SINT_TO_FP: return visitSINT_TO_FP(N);
|
|
case ISD::UINT_TO_FP: return visitUINT_TO_FP(N);
|
|
case ISD::FP_TO_SINT: return visitFP_TO_SINT(N);
|
|
case ISD::FP_TO_UINT: return visitFP_TO_UINT(N);
|
|
case ISD::FP_ROUND: return visitFP_ROUND(N);
|
|
case ISD::FP_ROUND_INREG: return visitFP_ROUND_INREG(N);
|
|
case ISD::FP_EXTEND: return visitFP_EXTEND(N);
|
|
case ISD::FNEG: return visitFNEG(N);
|
|
case ISD::FABS: return visitFABS(N);
|
|
case ISD::BRCOND: return visitBRCOND(N);
|
|
case ISD::BR_CC: return visitBR_CC(N);
|
|
case ISD::LOAD: return visitLOAD(N);
|
|
case ISD::STORE: return visitSTORE(N);
|
|
case ISD::INSERT_VECTOR_ELT: return visitINSERT_VECTOR_ELT(N);
|
|
case ISD::EXTRACT_VECTOR_ELT: return visitEXTRACT_VECTOR_ELT(N);
|
|
case ISD::BUILD_VECTOR: return visitBUILD_VECTOR(N);
|
|
case ISD::CONCAT_VECTORS: return visitCONCAT_VECTORS(N);
|
|
case ISD::VECTOR_SHUFFLE: return visitVECTOR_SHUFFLE(N);
|
|
}
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::combine(SDNode *N) {
|
|
|
|
SDOperand RV = visit(N);
|
|
|
|
// If nothing happened, try a target-specific DAG combine.
|
|
if (RV.Val == 0) {
|
|
assert(N->getOpcode() != ISD::DELETED_NODE &&
|
|
"Node was deleted but visit returned NULL!");
|
|
|
|
if (N->getOpcode() >= ISD::BUILTIN_OP_END ||
|
|
TLI.hasTargetDAGCombine((ISD::NodeType)N->getOpcode())) {
|
|
|
|
// Expose the DAG combiner to the target combiner impls.
|
|
TargetLowering::DAGCombinerInfo
|
|
DagCombineInfo(DAG, !AfterLegalize, false, this);
|
|
|
|
RV = TLI.PerformDAGCombine(N, DagCombineInfo);
|
|
}
|
|
}
|
|
|
|
return RV;
|
|
}
|
|
|
|
/// getInputChainForNode - Given a node, return its input chain if it has one,
|
|
/// otherwise return a null sd operand.
|
|
static SDOperand getInputChainForNode(SDNode *N) {
|
|
if (unsigned NumOps = N->getNumOperands()) {
|
|
if (N->getOperand(0).getValueType() == MVT::Other)
|
|
return N->getOperand(0);
|
|
else if (N->getOperand(NumOps-1).getValueType() == MVT::Other)
|
|
return N->getOperand(NumOps-1);
|
|
for (unsigned i = 1; i < NumOps-1; ++i)
|
|
if (N->getOperand(i).getValueType() == MVT::Other)
|
|
return N->getOperand(i);
|
|
}
|
|
return SDOperand(0, 0);
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitTokenFactor(SDNode *N) {
|
|
// If N has two operands, where one has an input chain equal to the other,
|
|
// the 'other' chain is redundant.
|
|
if (N->getNumOperands() == 2) {
|
|
if (getInputChainForNode(N->getOperand(0).Val) == N->getOperand(1))
|
|
return N->getOperand(0);
|
|
if (getInputChainForNode(N->getOperand(1).Val) == N->getOperand(0))
|
|
return N->getOperand(1);
|
|
}
|
|
|
|
SmallVector<SDNode *, 8> TFs; // List of token factors to visit.
|
|
SmallVector<SDOperand, 8> Ops; // Ops for replacing token factor.
|
|
SmallPtrSet<SDNode*, 16> SeenOps;
|
|
bool Changed = false; // If we should replace this token factor.
|
|
|
|
// Start out with this token factor.
|
|
TFs.push_back(N);
|
|
|
|
// Iterate through token factors. The TFs grows when new token factors are
|
|
// encountered.
|
|
for (unsigned i = 0; i < TFs.size(); ++i) {
|
|
SDNode *TF = TFs[i];
|
|
|
|
// Check each of the operands.
|
|
for (unsigned i = 0, ie = TF->getNumOperands(); i != ie; ++i) {
|
|
SDOperand Op = TF->getOperand(i);
|
|
|
|
switch (Op.getOpcode()) {
|
|
case ISD::EntryToken:
|
|
// Entry tokens don't need to be added to the list. They are
|
|
// rededundant.
|
|
Changed = true;
|
|
break;
|
|
|
|
case ISD::TokenFactor:
|
|
if ((CombinerAA || Op.hasOneUse()) &&
|
|
std::find(TFs.begin(), TFs.end(), Op.Val) == TFs.end()) {
|
|
// Queue up for processing.
|
|
TFs.push_back(Op.Val);
|
|
// Clean up in case the token factor is removed.
|
|
AddToWorkList(Op.Val);
|
|
Changed = true;
|
|
break;
|
|
}
|
|
// Fall thru
|
|
|
|
default:
|
|
// Only add if it isn't already in the list.
|
|
if (SeenOps.insert(Op.Val))
|
|
Ops.push_back(Op);
|
|
else
|
|
Changed = true;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
SDOperand Result;
|
|
|
|
// If we've change things around then replace token factor.
|
|
if (Changed) {
|
|
if (Ops.size() == 0) {
|
|
// The entry token is the only possible outcome.
|
|
Result = DAG.getEntryNode();
|
|
} else {
|
|
// New and improved token factor.
|
|
Result = DAG.getNode(ISD::TokenFactor, MVT::Other, &Ops[0], Ops.size());
|
|
}
|
|
|
|
// Don't add users to work list.
|
|
return CombineTo(N, Result, false);
|
|
}
|
|
|
|
return Result;
|
|
}
|
|
|
|
static
|
|
SDOperand combineShlAddConstant(SDOperand N0, SDOperand N1, SelectionDAG &DAG) {
|
|
MVT::ValueType VT = N0.getValueType();
|
|
SDOperand N00 = N0.getOperand(0);
|
|
SDOperand N01 = N0.getOperand(1);
|
|
ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N01);
|
|
if (N01C && N00.getOpcode() == ISD::ADD && N00.Val->hasOneUse() &&
|
|
isa<ConstantSDNode>(N00.getOperand(1))) {
|
|
N0 = DAG.getNode(ISD::ADD, VT,
|
|
DAG.getNode(ISD::SHL, VT, N00.getOperand(0), N01),
|
|
DAG.getNode(ISD::SHL, VT, N00.getOperand(1), N01));
|
|
return DAG.getNode(ISD::ADD, VT, N0, N1);
|
|
}
|
|
return SDOperand();
|
|
}
|
|
|
|
static
|
|
SDOperand combineSelectAndUse(SDNode *N, SDOperand Slct, SDOperand OtherOp,
|
|
SelectionDAG &DAG) {
|
|
MVT::ValueType VT = N->getValueType(0);
|
|
unsigned Opc = N->getOpcode();
|
|
bool isSlctCC = Slct.getOpcode() == ISD::SELECT_CC;
|
|
SDOperand LHS = isSlctCC ? Slct.getOperand(2) : Slct.getOperand(1);
|
|
SDOperand RHS = isSlctCC ? Slct.getOperand(3) : Slct.getOperand(2);
|
|
ISD::CondCode CC = ISD::SETCC_INVALID;
|
|
if (isSlctCC)
|
|
CC = cast<CondCodeSDNode>(Slct.getOperand(4))->get();
|
|
else {
|
|
SDOperand CCOp = Slct.getOperand(0);
|
|
if (CCOp.getOpcode() == ISD::SETCC)
|
|
CC = cast<CondCodeSDNode>(CCOp.getOperand(2))->get();
|
|
}
|
|
|
|
bool DoXform = false;
|
|
bool InvCC = false;
|
|
assert ((Opc == ISD::ADD || (Opc == ISD::SUB && Slct == N->getOperand(1))) &&
|
|
"Bad input!");
|
|
if (LHS.getOpcode() == ISD::Constant &&
|
|
cast<ConstantSDNode>(LHS)->isNullValue())
|
|
DoXform = true;
|
|
else if (CC != ISD::SETCC_INVALID &&
|
|
RHS.getOpcode() == ISD::Constant &&
|
|
cast<ConstantSDNode>(RHS)->isNullValue()) {
|
|
std::swap(LHS, RHS);
|
|
bool isInt = MVT::isInteger(isSlctCC ? Slct.getOperand(0).getValueType()
|
|
: Slct.getOperand(0).getOperand(0).getValueType());
|
|
CC = ISD::getSetCCInverse(CC, isInt);
|
|
DoXform = true;
|
|
InvCC = true;
|
|
}
|
|
|
|
if (DoXform) {
|
|
SDOperand Result = DAG.getNode(Opc, VT, OtherOp, RHS);
|
|
if (isSlctCC)
|
|
return DAG.getSelectCC(OtherOp, Result,
|
|
Slct.getOperand(0), Slct.getOperand(1), CC);
|
|
SDOperand CCOp = Slct.getOperand(0);
|
|
if (InvCC)
|
|
CCOp = DAG.getSetCC(CCOp.getValueType(), CCOp.getOperand(0),
|
|
CCOp.getOperand(1), CC);
|
|
return DAG.getNode(ISD::SELECT, VT, CCOp, OtherOp, Result);
|
|
}
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitADD(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
SDOperand N1 = N->getOperand(1);
|
|
ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
|
|
ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
|
|
MVT::ValueType VT = N0.getValueType();
|
|
|
|
// fold vector ops
|
|
if (MVT::isVector(VT)) {
|
|
SDOperand FoldedVOp = SimplifyVBinOp(N);
|
|
if (FoldedVOp.Val) return FoldedVOp;
|
|
}
|
|
|
|
// fold (add x, undef) -> undef
|
|
if (N0.getOpcode() == ISD::UNDEF)
|
|
return N0;
|
|
if (N1.getOpcode() == ISD::UNDEF)
|
|
return N1;
|
|
// fold (add c1, c2) -> c1+c2
|
|
if (N0C && N1C)
|
|
return DAG.getNode(ISD::ADD, VT, N0, N1);
|
|
// canonicalize constant to RHS
|
|
if (N0C && !N1C)
|
|
return DAG.getNode(ISD::ADD, VT, N1, N0);
|
|
// fold (add x, 0) -> x
|
|
if (N1C && N1C->isNullValue())
|
|
return N0;
|
|
// fold ((c1-A)+c2) -> (c1+c2)-A
|
|
if (N1C && N0.getOpcode() == ISD::SUB)
|
|
if (ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.getOperand(0)))
|
|
return DAG.getNode(ISD::SUB, VT,
|
|
DAG.getConstant(N1C->getValue()+N0C->getValue(), VT),
|
|
N0.getOperand(1));
|
|
// reassociate add
|
|
SDOperand RADD = ReassociateOps(ISD::ADD, N0, N1);
|
|
if (RADD.Val != 0)
|
|
return RADD;
|
|
// fold ((0-A) + B) -> B-A
|
|
if (N0.getOpcode() == ISD::SUB && isa<ConstantSDNode>(N0.getOperand(0)) &&
|
|
cast<ConstantSDNode>(N0.getOperand(0))->isNullValue())
|
|
return DAG.getNode(ISD::SUB, VT, N1, N0.getOperand(1));
|
|
// fold (A + (0-B)) -> A-B
|
|
if (N1.getOpcode() == ISD::SUB && isa<ConstantSDNode>(N1.getOperand(0)) &&
|
|
cast<ConstantSDNode>(N1.getOperand(0))->isNullValue())
|
|
return DAG.getNode(ISD::SUB, VT, N0, N1.getOperand(1));
|
|
// fold (A+(B-A)) -> B
|
|
if (N1.getOpcode() == ISD::SUB && N0 == N1.getOperand(1))
|
|
return N1.getOperand(0);
|
|
|
|
if (!MVT::isVector(VT) && SimplifyDemandedBits(SDOperand(N, 0)))
|
|
return SDOperand(N, 0);
|
|
|
|
// fold (a+b) -> (a|b) iff a and b share no bits.
|
|
if (MVT::isInteger(VT) && !MVT::isVector(VT)) {
|
|
uint64_t LHSZero, LHSOne;
|
|
uint64_t RHSZero, RHSOne;
|
|
uint64_t Mask = MVT::getIntVTBitMask(VT);
|
|
DAG.ComputeMaskedBits(N0, Mask, LHSZero, LHSOne);
|
|
if (LHSZero) {
|
|
DAG.ComputeMaskedBits(N1, Mask, RHSZero, RHSOne);
|
|
|
|
// If all possibly-set bits on the LHS are clear on the RHS, return an OR.
|
|
// If all possibly-set bits on the RHS are clear on the LHS, return an OR.
|
|
if ((RHSZero & (~LHSZero & Mask)) == (~LHSZero & Mask) ||
|
|
(LHSZero & (~RHSZero & Mask)) == (~RHSZero & Mask))
|
|
return DAG.getNode(ISD::OR, VT, N0, N1);
|
|
}
|
|
}
|
|
|
|
// fold (add (shl (add x, c1), c2), ) -> (add (add (shl x, c2), c1<<c2), )
|
|
if (N0.getOpcode() == ISD::SHL && N0.Val->hasOneUse()) {
|
|
SDOperand Result = combineShlAddConstant(N0, N1, DAG);
|
|
if (Result.Val) return Result;
|
|
}
|
|
if (N1.getOpcode() == ISD::SHL && N1.Val->hasOneUse()) {
|
|
SDOperand Result = combineShlAddConstant(N1, N0, DAG);
|
|
if (Result.Val) return Result;
|
|
}
|
|
|
|
// fold (add (select cc, 0, c), x) -> (select cc, x, (add, x, c))
|
|
if (N0.getOpcode() == ISD::SELECT && N0.Val->hasOneUse()) {
|
|
SDOperand Result = combineSelectAndUse(N, N0, N1, DAG);
|
|
if (Result.Val) return Result;
|
|
}
|
|
if (N1.getOpcode() == ISD::SELECT && N1.Val->hasOneUse()) {
|
|
SDOperand Result = combineSelectAndUse(N, N1, N0, DAG);
|
|
if (Result.Val) return Result;
|
|
}
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitADDC(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
SDOperand N1 = N->getOperand(1);
|
|
ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
|
|
ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
|
|
MVT::ValueType VT = N0.getValueType();
|
|
|
|
// If the flag result is dead, turn this into an ADD.
|
|
if (N->hasNUsesOfValue(0, 1))
|
|
return CombineTo(N, DAG.getNode(ISD::ADD, VT, N1, N0),
|
|
DAG.getNode(ISD::CARRY_FALSE, MVT::Flag));
|
|
|
|
// canonicalize constant to RHS.
|
|
if (N0C && !N1C) {
|
|
SDOperand Ops[] = { N1, N0 };
|
|
return DAG.getNode(ISD::ADDC, N->getVTList(), Ops, 2);
|
|
}
|
|
|
|
// fold (addc x, 0) -> x + no carry out
|
|
if (N1C && N1C->isNullValue())
|
|
return CombineTo(N, N0, DAG.getNode(ISD::CARRY_FALSE, MVT::Flag));
|
|
|
|
// fold (addc a, b) -> (or a, b), CARRY_FALSE iff a and b share no bits.
|
|
uint64_t LHSZero, LHSOne;
|
|
uint64_t RHSZero, RHSOne;
|
|
uint64_t Mask = MVT::getIntVTBitMask(VT);
|
|
DAG.ComputeMaskedBits(N0, Mask, LHSZero, LHSOne);
|
|
if (LHSZero) {
|
|
DAG.ComputeMaskedBits(N1, Mask, RHSZero, RHSOne);
|
|
|
|
// If all possibly-set bits on the LHS are clear on the RHS, return an OR.
|
|
// If all possibly-set bits on the RHS are clear on the LHS, return an OR.
|
|
if ((RHSZero & (~LHSZero & Mask)) == (~LHSZero & Mask) ||
|
|
(LHSZero & (~RHSZero & Mask)) == (~RHSZero & Mask))
|
|
return CombineTo(N, DAG.getNode(ISD::OR, VT, N0, N1),
|
|
DAG.getNode(ISD::CARRY_FALSE, MVT::Flag));
|
|
}
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitADDE(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
SDOperand N1 = N->getOperand(1);
|
|
SDOperand CarryIn = N->getOperand(2);
|
|
ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
|
|
ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
|
|
//MVT::ValueType VT = N0.getValueType();
|
|
|
|
// canonicalize constant to RHS
|
|
if (N0C && !N1C) {
|
|
SDOperand Ops[] = { N1, N0, CarryIn };
|
|
return DAG.getNode(ISD::ADDE, N->getVTList(), Ops, 3);
|
|
}
|
|
|
|
// fold (adde x, y, false) -> (addc x, y)
|
|
if (CarryIn.getOpcode() == ISD::CARRY_FALSE) {
|
|
SDOperand Ops[] = { N1, N0 };
|
|
return DAG.getNode(ISD::ADDC, N->getVTList(), Ops, 2);
|
|
}
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
|
|
|
|
SDOperand DAGCombiner::visitSUB(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
SDOperand N1 = N->getOperand(1);
|
|
ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.Val);
|
|
ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.Val);
|
|
MVT::ValueType VT = N0.getValueType();
|
|
|
|
// fold vector ops
|
|
if (MVT::isVector(VT)) {
|
|
SDOperand FoldedVOp = SimplifyVBinOp(N);
|
|
if (FoldedVOp.Val) return FoldedVOp;
|
|
}
|
|
|
|
// fold (sub x, x) -> 0
|
|
if (N0 == N1)
|
|
return DAG.getConstant(0, N->getValueType(0));
|
|
// fold (sub c1, c2) -> c1-c2
|
|
if (N0C && N1C)
|
|
return DAG.getNode(ISD::SUB, VT, N0, N1);
|
|
// fold (sub x, c) -> (add x, -c)
|
|
if (N1C)
|
|
return DAG.getNode(ISD::ADD, VT, N0, DAG.getConstant(-N1C->getValue(), VT));
|
|
// fold (A+B)-A -> B
|
|
if (N0.getOpcode() == ISD::ADD && N0.getOperand(0) == N1)
|
|
return N0.getOperand(1);
|
|
// fold (A+B)-B -> A
|
|
if (N0.getOpcode() == ISD::ADD && N0.getOperand(1) == N1)
|
|
return N0.getOperand(0);
|
|
// fold (sub x, (select cc, 0, c)) -> (select cc, x, (sub, x, c))
|
|
if (N1.getOpcode() == ISD::SELECT && N1.Val->hasOneUse()) {
|
|
SDOperand Result = combineSelectAndUse(N, N1, N0, DAG);
|
|
if (Result.Val) return Result;
|
|
}
|
|
// If either operand of a sub is undef, the result is undef
|
|
if (N0.getOpcode() == ISD::UNDEF)
|
|
return N0;
|
|
if (N1.getOpcode() == ISD::UNDEF)
|
|
return N1;
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitMUL(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
SDOperand N1 = N->getOperand(1);
|
|
ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
|
|
ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
|
|
MVT::ValueType VT = N0.getValueType();
|
|
|
|
// fold vector ops
|
|
if (MVT::isVector(VT)) {
|
|
SDOperand FoldedVOp = SimplifyVBinOp(N);
|
|
if (FoldedVOp.Val) return FoldedVOp;
|
|
}
|
|
|
|
// fold (mul x, undef) -> 0
|
|
if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
|
|
return DAG.getConstant(0, VT);
|
|
// fold (mul c1, c2) -> c1*c2
|
|
if (N0C && N1C)
|
|
return DAG.getNode(ISD::MUL, VT, N0, N1);
|
|
// canonicalize constant to RHS
|
|
if (N0C && !N1C)
|
|
return DAG.getNode(ISD::MUL, VT, N1, N0);
|
|
// fold (mul x, 0) -> 0
|
|
if (N1C && N1C->isNullValue())
|
|
return N1;
|
|
// fold (mul x, -1) -> 0-x
|
|
if (N1C && N1C->isAllOnesValue())
|
|
return DAG.getNode(ISD::SUB, VT, DAG.getConstant(0, VT), N0);
|
|
// fold (mul x, (1 << c)) -> x << c
|
|
if (N1C && isPowerOf2_64(N1C->getValue()))
|
|
return DAG.getNode(ISD::SHL, VT, N0,
|
|
DAG.getConstant(Log2_64(N1C->getValue()),
|
|
TLI.getShiftAmountTy()));
|
|
// fold (mul x, -(1 << c)) -> -(x << c) or (-x) << c
|
|
if (N1C && isPowerOf2_64(-N1C->getSignExtended())) {
|
|
// FIXME: If the input is something that is easily negated (e.g. a
|
|
// single-use add), we should put the negate there.
|
|
return DAG.getNode(ISD::SUB, VT, DAG.getConstant(0, VT),
|
|
DAG.getNode(ISD::SHL, VT, N0,
|
|
DAG.getConstant(Log2_64(-N1C->getSignExtended()),
|
|
TLI.getShiftAmountTy())));
|
|
}
|
|
|
|
// (mul (shl X, c1), c2) -> (mul X, c2 << c1)
|
|
if (N1C && N0.getOpcode() == ISD::SHL &&
|
|
isa<ConstantSDNode>(N0.getOperand(1))) {
|
|
SDOperand C3 = DAG.getNode(ISD::SHL, VT, N1, N0.getOperand(1));
|
|
AddToWorkList(C3.Val);
|
|
return DAG.getNode(ISD::MUL, VT, N0.getOperand(0), C3);
|
|
}
|
|
|
|
// Change (mul (shl X, C), Y) -> (shl (mul X, Y), C) when the shift has one
|
|
// use.
|
|
{
|
|
SDOperand Sh(0,0), Y(0,0);
|
|
// Check for both (mul (shl X, C), Y) and (mul Y, (shl X, C)).
|
|
if (N0.getOpcode() == ISD::SHL && isa<ConstantSDNode>(N0.getOperand(1)) &&
|
|
N0.Val->hasOneUse()) {
|
|
Sh = N0; Y = N1;
|
|
} else if (N1.getOpcode() == ISD::SHL &&
|
|
isa<ConstantSDNode>(N1.getOperand(1)) && N1.Val->hasOneUse()) {
|
|
Sh = N1; Y = N0;
|
|
}
|
|
if (Sh.Val) {
|
|
SDOperand Mul = DAG.getNode(ISD::MUL, VT, Sh.getOperand(0), Y);
|
|
return DAG.getNode(ISD::SHL, VT, Mul, Sh.getOperand(1));
|
|
}
|
|
}
|
|
// fold (mul (add x, c1), c2) -> (add (mul x, c2), c1*c2)
|
|
if (N1C && N0.getOpcode() == ISD::ADD && N0.Val->hasOneUse() &&
|
|
isa<ConstantSDNode>(N0.getOperand(1))) {
|
|
return DAG.getNode(ISD::ADD, VT,
|
|
DAG.getNode(ISD::MUL, VT, N0.getOperand(0), N1),
|
|
DAG.getNode(ISD::MUL, VT, N0.getOperand(1), N1));
|
|
}
|
|
|
|
// reassociate mul
|
|
SDOperand RMUL = ReassociateOps(ISD::MUL, N0, N1);
|
|
if (RMUL.Val != 0)
|
|
return RMUL;
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitSDIV(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
SDOperand N1 = N->getOperand(1);
|
|
ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.Val);
|
|
ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.Val);
|
|
MVT::ValueType VT = N->getValueType(0);
|
|
|
|
// fold vector ops
|
|
if (MVT::isVector(VT)) {
|
|
SDOperand FoldedVOp = SimplifyVBinOp(N);
|
|
if (FoldedVOp.Val) return FoldedVOp;
|
|
}
|
|
|
|
// fold (sdiv c1, c2) -> c1/c2
|
|
if (N0C && N1C && !N1C->isNullValue())
|
|
return DAG.getNode(ISD::SDIV, VT, N0, N1);
|
|
// fold (sdiv X, 1) -> X
|
|
if (N1C && N1C->getSignExtended() == 1LL)
|
|
return N0;
|
|
// fold (sdiv X, -1) -> 0-X
|
|
if (N1C && N1C->isAllOnesValue())
|
|
return DAG.getNode(ISD::SUB, VT, DAG.getConstant(0, VT), N0);
|
|
// If we know the sign bits of both operands are zero, strength reduce to a
|
|
// udiv instead. Handles (X&15) /s 4 -> X&15 >> 2
|
|
uint64_t SignBit = 1ULL << (MVT::getSizeInBits(VT)-1);
|
|
if (DAG.MaskedValueIsZero(N1, SignBit) &&
|
|
DAG.MaskedValueIsZero(N0, SignBit))
|
|
return DAG.getNode(ISD::UDIV, N1.getValueType(), N0, N1);
|
|
// fold (sdiv X, pow2) -> simple ops after legalize
|
|
if (N1C && N1C->getValue() && !TLI.isIntDivCheap() &&
|
|
(isPowerOf2_64(N1C->getSignExtended()) ||
|
|
isPowerOf2_64(-N1C->getSignExtended()))) {
|
|
// If dividing by powers of two is cheap, then don't perform the following
|
|
// fold.
|
|
if (TLI.isPow2DivCheap())
|
|
return SDOperand();
|
|
int64_t pow2 = N1C->getSignExtended();
|
|
int64_t abs2 = pow2 > 0 ? pow2 : -pow2;
|
|
unsigned lg2 = Log2_64(abs2);
|
|
// Splat the sign bit into the register
|
|
SDOperand SGN = DAG.getNode(ISD::SRA, VT, N0,
|
|
DAG.getConstant(MVT::getSizeInBits(VT)-1,
|
|
TLI.getShiftAmountTy()));
|
|
AddToWorkList(SGN.Val);
|
|
// Add (N0 < 0) ? abs2 - 1 : 0;
|
|
SDOperand SRL = DAG.getNode(ISD::SRL, VT, SGN,
|
|
DAG.getConstant(MVT::getSizeInBits(VT)-lg2,
|
|
TLI.getShiftAmountTy()));
|
|
SDOperand ADD = DAG.getNode(ISD::ADD, VT, N0, SRL);
|
|
AddToWorkList(SRL.Val);
|
|
AddToWorkList(ADD.Val); // Divide by pow2
|
|
SDOperand SRA = DAG.getNode(ISD::SRA, VT, ADD,
|
|
DAG.getConstant(lg2, TLI.getShiftAmountTy()));
|
|
// If we're dividing by a positive value, we're done. Otherwise, we must
|
|
// negate the result.
|
|
if (pow2 > 0)
|
|
return SRA;
|
|
AddToWorkList(SRA.Val);
|
|
return DAG.getNode(ISD::SUB, VT, DAG.getConstant(0, VT), SRA);
|
|
}
|
|
// if integer divide is expensive and we satisfy the requirements, emit an
|
|
// alternate sequence.
|
|
if (N1C && (N1C->getSignExtended() < -1 || N1C->getSignExtended() > 1) &&
|
|
!TLI.isIntDivCheap()) {
|
|
SDOperand Op = BuildSDIV(N);
|
|
if (Op.Val) return Op;
|
|
}
|
|
|
|
// undef / X -> 0
|
|
if (N0.getOpcode() == ISD::UNDEF)
|
|
return DAG.getConstant(0, VT);
|
|
// X / undef -> undef
|
|
if (N1.getOpcode() == ISD::UNDEF)
|
|
return N1;
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitUDIV(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
SDOperand N1 = N->getOperand(1);
|
|
ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0.Val);
|
|
ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.Val);
|
|
MVT::ValueType VT = N->getValueType(0);
|
|
|
|
// fold vector ops
|
|
if (MVT::isVector(VT)) {
|
|
SDOperand FoldedVOp = SimplifyVBinOp(N);
|
|
if (FoldedVOp.Val) return FoldedVOp;
|
|
}
|
|
|
|
// fold (udiv c1, c2) -> c1/c2
|
|
if (N0C && N1C && !N1C->isNullValue())
|
|
return DAG.getNode(ISD::UDIV, VT, N0, N1);
|
|
// fold (udiv x, (1 << c)) -> x >>u c
|
|
if (N1C && isPowerOf2_64(N1C->getValue()))
|
|
return DAG.getNode(ISD::SRL, VT, N0,
|
|
DAG.getConstant(Log2_64(N1C->getValue()),
|
|
TLI.getShiftAmountTy()));
|
|
// fold (udiv x, (shl c, y)) -> x >>u (log2(c)+y) iff c is power of 2
|
|
if (N1.getOpcode() == ISD::SHL) {
|
|
if (ConstantSDNode *SHC = dyn_cast<ConstantSDNode>(N1.getOperand(0))) {
|
|
if (isPowerOf2_64(SHC->getValue())) {
|
|
MVT::ValueType ADDVT = N1.getOperand(1).getValueType();
|
|
SDOperand Add = DAG.getNode(ISD::ADD, ADDVT, N1.getOperand(1),
|
|
DAG.getConstant(Log2_64(SHC->getValue()),
|
|
ADDVT));
|
|
AddToWorkList(Add.Val);
|
|
return DAG.getNode(ISD::SRL, VT, N0, Add);
|
|
}
|
|
}
|
|
}
|
|
// fold (udiv x, c) -> alternate
|
|
if (N1C && N1C->getValue() && !TLI.isIntDivCheap()) {
|
|
SDOperand Op = BuildUDIV(N);
|
|
if (Op.Val) return Op;
|
|
}
|
|
|
|
// undef / X -> 0
|
|
if (N0.getOpcode() == ISD::UNDEF)
|
|
return DAG.getConstant(0, VT);
|
|
// X / undef -> undef
|
|
if (N1.getOpcode() == ISD::UNDEF)
|
|
return N1;
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitSREM(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
SDOperand N1 = N->getOperand(1);
|
|
ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
|
|
ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
|
|
MVT::ValueType VT = N->getValueType(0);
|
|
|
|
// fold (srem c1, c2) -> c1%c2
|
|
if (N0C && N1C && !N1C->isNullValue())
|
|
return DAG.getNode(ISD::SREM, VT, N0, N1);
|
|
// If we know the sign bits of both operands are zero, strength reduce to a
|
|
// urem instead. Handles (X & 0x0FFFFFFF) %s 16 -> X&15
|
|
uint64_t SignBit = 1ULL << (MVT::getSizeInBits(VT)-1);
|
|
if (DAG.MaskedValueIsZero(N1, SignBit) &&
|
|
DAG.MaskedValueIsZero(N0, SignBit))
|
|
return DAG.getNode(ISD::UREM, VT, N0, N1);
|
|
|
|
// Unconditionally lower X%C -> X-X/C*C. This allows the X/C logic to hack on
|
|
// the remainder operation.
|
|
if (N1C && !N1C->isNullValue()) {
|
|
SDOperand Div = DAG.getNode(ISD::SDIV, VT, N0, N1);
|
|
SDOperand Mul = DAG.getNode(ISD::MUL, VT, Div, N1);
|
|
SDOperand Sub = DAG.getNode(ISD::SUB, VT, N0, Mul);
|
|
AddToWorkList(Div.Val);
|
|
AddToWorkList(Mul.Val);
|
|
return Sub;
|
|
}
|
|
|
|
// undef % X -> 0
|
|
if (N0.getOpcode() == ISD::UNDEF)
|
|
return DAG.getConstant(0, VT);
|
|
// X % undef -> undef
|
|
if (N1.getOpcode() == ISD::UNDEF)
|
|
return N1;
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitUREM(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
SDOperand N1 = N->getOperand(1);
|
|
ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
|
|
ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
|
|
MVT::ValueType VT = N->getValueType(0);
|
|
|
|
// fold (urem c1, c2) -> c1%c2
|
|
if (N0C && N1C && !N1C->isNullValue())
|
|
return DAG.getNode(ISD::UREM, VT, N0, N1);
|
|
// fold (urem x, pow2) -> (and x, pow2-1)
|
|
if (N1C && !N1C->isNullValue() && isPowerOf2_64(N1C->getValue()))
|
|
return DAG.getNode(ISD::AND, VT, N0, DAG.getConstant(N1C->getValue()-1,VT));
|
|
// fold (urem x, (shl pow2, y)) -> (and x, (add (shl pow2, y), -1))
|
|
if (N1.getOpcode() == ISD::SHL) {
|
|
if (ConstantSDNode *SHC = dyn_cast<ConstantSDNode>(N1.getOperand(0))) {
|
|
if (isPowerOf2_64(SHC->getValue())) {
|
|
SDOperand Add = DAG.getNode(ISD::ADD, VT, N1,DAG.getConstant(~0ULL,VT));
|
|
AddToWorkList(Add.Val);
|
|
return DAG.getNode(ISD::AND, VT, N0, Add);
|
|
}
|
|
}
|
|
}
|
|
|
|
// Unconditionally lower X%C -> X-X/C*C. This allows the X/C logic to hack on
|
|
// the remainder operation.
|
|
if (N1C && !N1C->isNullValue()) {
|
|
SDOperand Div = DAG.getNode(ISD::UDIV, VT, N0, N1);
|
|
SDOperand Mul = DAG.getNode(ISD::MUL, VT, Div, N1);
|
|
SDOperand Sub = DAG.getNode(ISD::SUB, VT, N0, Mul);
|
|
AddToWorkList(Div.Val);
|
|
AddToWorkList(Mul.Val);
|
|
return Sub;
|
|
}
|
|
|
|
// undef % X -> 0
|
|
if (N0.getOpcode() == ISD::UNDEF)
|
|
return DAG.getConstant(0, VT);
|
|
// X % undef -> undef
|
|
if (N1.getOpcode() == ISD::UNDEF)
|
|
return N1;
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitMULHS(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
SDOperand N1 = N->getOperand(1);
|
|
ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
|
|
MVT::ValueType VT = N->getValueType(0);
|
|
|
|
// fold (mulhs x, 0) -> 0
|
|
if (N1C && N1C->isNullValue())
|
|
return N1;
|
|
// fold (mulhs x, 1) -> (sra x, size(x)-1)
|
|
if (N1C && N1C->getValue() == 1)
|
|
return DAG.getNode(ISD::SRA, N0.getValueType(), N0,
|
|
DAG.getConstant(MVT::getSizeInBits(N0.getValueType())-1,
|
|
TLI.getShiftAmountTy()));
|
|
// fold (mulhs x, undef) -> 0
|
|
if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
|
|
return DAG.getConstant(0, VT);
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitMULHU(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
SDOperand N1 = N->getOperand(1);
|
|
ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
|
|
MVT::ValueType VT = N->getValueType(0);
|
|
|
|
// fold (mulhu x, 0) -> 0
|
|
if (N1C && N1C->isNullValue())
|
|
return N1;
|
|
// fold (mulhu x, 1) -> 0
|
|
if (N1C && N1C->getValue() == 1)
|
|
return DAG.getConstant(0, N0.getValueType());
|
|
// fold (mulhu x, undef) -> 0
|
|
if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
|
|
return DAG.getConstant(0, VT);
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
/// SimplifyNodeWithTwoResults - Perform optimizations common to nodes that
|
|
/// compute two values. LoOp and HiOp give the opcodes for the two computations
|
|
/// that are being performed. Return true if a simplification was made.
|
|
///
|
|
bool DAGCombiner::SimplifyNodeWithTwoResults(SDNode *N,
|
|
unsigned LoOp, unsigned HiOp) {
|
|
// If the high half is not needed, just compute the low half.
|
|
if (!N->hasAnyUseOfValue(1) &&
|
|
(!AfterLegalize ||
|
|
TLI.isOperationLegal(LoOp, N->getValueType(0)))) {
|
|
DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 0),
|
|
DAG.getNode(LoOp, N->getValueType(0),
|
|
N->op_begin(),
|
|
N->getNumOperands()));
|
|
return true;
|
|
}
|
|
|
|
// If the low half is not needed, just compute the high half.
|
|
if (!N->hasAnyUseOfValue(0) &&
|
|
(!AfterLegalize ||
|
|
TLI.isOperationLegal(HiOp, N->getValueType(1)))) {
|
|
DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 1),
|
|
DAG.getNode(HiOp, N->getValueType(1),
|
|
N->op_begin(),
|
|
N->getNumOperands()));
|
|
return true;
|
|
}
|
|
|
|
// If the two computed results can be siplified separately, separate them.
|
|
SDOperand Lo = DAG.getNode(LoOp, N->getValueType(0),
|
|
N->op_begin(), N->getNumOperands());
|
|
SDOperand Hi = DAG.getNode(HiOp, N->getValueType(1),
|
|
N->op_begin(), N->getNumOperands());
|
|
unsigned LoExists = !Lo.use_empty();
|
|
unsigned HiExists = !Hi.use_empty();
|
|
SDOperand LoOpt = Lo;
|
|
SDOperand HiOpt = Hi;
|
|
if (!LoExists || !HiExists) {
|
|
SDOperand Pair = DAG.getNode(ISD::BUILD_PAIR, MVT::Other, Lo, Hi);
|
|
assert(Pair.use_empty() && "Pair with type MVT::Other already exists!");
|
|
LoOpt = combine(Lo.Val);
|
|
HiOpt = combine(Hi.Val);
|
|
if (!LoOpt.Val)
|
|
LoOpt = Pair.getOperand(0);
|
|
if (!HiOpt.Val)
|
|
HiOpt = Pair.getOperand(1);
|
|
DAG.DeleteNode(Pair.Val);
|
|
}
|
|
if ((LoExists || LoOpt != Lo) &&
|
|
(HiExists || HiOpt != Hi) &&
|
|
TLI.isOperationLegal(LoOpt.getOpcode(), LoOpt.getValueType()) &&
|
|
TLI.isOperationLegal(HiOpt.getOpcode(), HiOpt.getValueType())) {
|
|
DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 0), LoOpt);
|
|
DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 1), HiOpt);
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitSMUL_LOHI(SDNode *N) {
|
|
|
|
if (SimplifyNodeWithTwoResults(N, ISD::MUL, ISD::MULHS))
|
|
return SDOperand();
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitUMUL_LOHI(SDNode *N) {
|
|
|
|
if (SimplifyNodeWithTwoResults(N, ISD::MUL, ISD::MULHU))
|
|
return SDOperand();
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitSDIVREM(SDNode *N) {
|
|
|
|
if (SimplifyNodeWithTwoResults(N, ISD::SDIV, ISD::SREM))
|
|
return SDOperand();
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitUDIVREM(SDNode *N) {
|
|
|
|
if (SimplifyNodeWithTwoResults(N, ISD::UDIV, ISD::UREM))
|
|
return SDOperand();
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
/// SimplifyBinOpWithSameOpcodeHands - If this is a binary operator with
|
|
/// two operands of the same opcode, try to simplify it.
|
|
SDOperand DAGCombiner::SimplifyBinOpWithSameOpcodeHands(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0), N1 = N->getOperand(1);
|
|
MVT::ValueType VT = N0.getValueType();
|
|
assert(N0.getOpcode() == N1.getOpcode() && "Bad input!");
|
|
|
|
// For each of OP in AND/OR/XOR:
|
|
// fold (OP (zext x), (zext y)) -> (zext (OP x, y))
|
|
// fold (OP (sext x), (sext y)) -> (sext (OP x, y))
|
|
// fold (OP (aext x), (aext y)) -> (aext (OP x, y))
|
|
// fold (OP (trunc x), (trunc y)) -> (trunc (OP x, y))
|
|
if ((N0.getOpcode() == ISD::ZERO_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND||
|
|
N0.getOpcode() == ISD::SIGN_EXTEND || N0.getOpcode() == ISD::TRUNCATE) &&
|
|
N0.getOperand(0).getValueType() == N1.getOperand(0).getValueType()) {
|
|
SDOperand ORNode = DAG.getNode(N->getOpcode(),
|
|
N0.getOperand(0).getValueType(),
|
|
N0.getOperand(0), N1.getOperand(0));
|
|
AddToWorkList(ORNode.Val);
|
|
return DAG.getNode(N0.getOpcode(), VT, ORNode);
|
|
}
|
|
|
|
// For each of OP in SHL/SRL/SRA/AND...
|
|
// fold (and (OP x, z), (OP y, z)) -> (OP (and x, y), z)
|
|
// fold (or (OP x, z), (OP y, z)) -> (OP (or x, y), z)
|
|
// fold (xor (OP x, z), (OP y, z)) -> (OP (xor x, y), z)
|
|
if ((N0.getOpcode() == ISD::SHL || N0.getOpcode() == ISD::SRL ||
|
|
N0.getOpcode() == ISD::SRA || N0.getOpcode() == ISD::AND) &&
|
|
N0.getOperand(1) == N1.getOperand(1)) {
|
|
SDOperand ORNode = DAG.getNode(N->getOpcode(),
|
|
N0.getOperand(0).getValueType(),
|
|
N0.getOperand(0), N1.getOperand(0));
|
|
AddToWorkList(ORNode.Val);
|
|
return DAG.getNode(N0.getOpcode(), VT, ORNode, N0.getOperand(1));
|
|
}
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitAND(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
SDOperand N1 = N->getOperand(1);
|
|
SDOperand LL, LR, RL, RR, CC0, CC1;
|
|
ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
|
|
ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
|
|
MVT::ValueType VT = N1.getValueType();
|
|
|
|
// fold vector ops
|
|
if (MVT::isVector(VT)) {
|
|
SDOperand FoldedVOp = SimplifyVBinOp(N);
|
|
if (FoldedVOp.Val) return FoldedVOp;
|
|
}
|
|
|
|
// fold (and x, undef) -> 0
|
|
if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
|
|
return DAG.getConstant(0, VT);
|
|
// fold (and c1, c2) -> c1&c2
|
|
if (N0C && N1C)
|
|
return DAG.getNode(ISD::AND, VT, N0, N1);
|
|
// canonicalize constant to RHS
|
|
if (N0C && !N1C)
|
|
return DAG.getNode(ISD::AND, VT, N1, N0);
|
|
// fold (and x, -1) -> x
|
|
if (N1C && N1C->isAllOnesValue())
|
|
return N0;
|
|
// if (and x, c) is known to be zero, return 0
|
|
if (N1C && DAG.MaskedValueIsZero(SDOperand(N, 0), MVT::getIntVTBitMask(VT)))
|
|
return DAG.getConstant(0, VT);
|
|
// reassociate and
|
|
SDOperand RAND = ReassociateOps(ISD::AND, N0, N1);
|
|
if (RAND.Val != 0)
|
|
return RAND;
|
|
// fold (and (or x, 0xFFFF), 0xFF) -> 0xFF
|
|
if (N1C && N0.getOpcode() == ISD::OR)
|
|
if (ConstantSDNode *ORI = dyn_cast<ConstantSDNode>(N0.getOperand(1)))
|
|
if ((ORI->getValue() & N1C->getValue()) == N1C->getValue())
|
|
return N1;
|
|
// fold (and (any_ext V), c) -> (zero_ext V) if 'and' only clears top bits.
|
|
if (N1C && N0.getOpcode() == ISD::ANY_EXTEND) {
|
|
unsigned InMask = MVT::getIntVTBitMask(N0.getOperand(0).getValueType());
|
|
if (DAG.MaskedValueIsZero(N0.getOperand(0),
|
|
~N1C->getValue() & InMask)) {
|
|
SDOperand Zext = DAG.getNode(ISD::ZERO_EXTEND, N0.getValueType(),
|
|
N0.getOperand(0));
|
|
|
|
// Replace uses of the AND with uses of the Zero extend node.
|
|
CombineTo(N, Zext);
|
|
|
|
// We actually want to replace all uses of the any_extend with the
|
|
// zero_extend, to avoid duplicating things. This will later cause this
|
|
// AND to be folded.
|
|
CombineTo(N0.Val, Zext);
|
|
return SDOperand(N, 0); // Return N so it doesn't get rechecked!
|
|
}
|
|
}
|
|
// fold (and (setcc x), (setcc y)) -> (setcc (and x, y))
|
|
if (isSetCCEquivalent(N0, LL, LR, CC0) && isSetCCEquivalent(N1, RL, RR, CC1)){
|
|
ISD::CondCode Op0 = cast<CondCodeSDNode>(CC0)->get();
|
|
ISD::CondCode Op1 = cast<CondCodeSDNode>(CC1)->get();
|
|
|
|
if (LR == RR && isa<ConstantSDNode>(LR) && Op0 == Op1 &&
|
|
MVT::isInteger(LL.getValueType())) {
|
|
// fold (X == 0) & (Y == 0) -> (X|Y == 0)
|
|
if (cast<ConstantSDNode>(LR)->getValue() == 0 && Op1 == ISD::SETEQ) {
|
|
SDOperand ORNode = DAG.getNode(ISD::OR, LR.getValueType(), LL, RL);
|
|
AddToWorkList(ORNode.Val);
|
|
return DAG.getSetCC(VT, ORNode, LR, Op1);
|
|
}
|
|
// fold (X == -1) & (Y == -1) -> (X&Y == -1)
|
|
if (cast<ConstantSDNode>(LR)->isAllOnesValue() && Op1 == ISD::SETEQ) {
|
|
SDOperand ANDNode = DAG.getNode(ISD::AND, LR.getValueType(), LL, RL);
|
|
AddToWorkList(ANDNode.Val);
|
|
return DAG.getSetCC(VT, ANDNode, LR, Op1);
|
|
}
|
|
// fold (X > -1) & (Y > -1) -> (X|Y > -1)
|
|
if (cast<ConstantSDNode>(LR)->isAllOnesValue() && Op1 == ISD::SETGT) {
|
|
SDOperand ORNode = DAG.getNode(ISD::OR, LR.getValueType(), LL, RL);
|
|
AddToWorkList(ORNode.Val);
|
|
return DAG.getSetCC(VT, ORNode, LR, Op1);
|
|
}
|
|
}
|
|
// canonicalize equivalent to ll == rl
|
|
if (LL == RR && LR == RL) {
|
|
Op1 = ISD::getSetCCSwappedOperands(Op1);
|
|
std::swap(RL, RR);
|
|
}
|
|
if (LL == RL && LR == RR) {
|
|
bool isInteger = MVT::isInteger(LL.getValueType());
|
|
ISD::CondCode Result = ISD::getSetCCAndOperation(Op0, Op1, isInteger);
|
|
if (Result != ISD::SETCC_INVALID)
|
|
return DAG.getSetCC(N0.getValueType(), LL, LR, Result);
|
|
}
|
|
}
|
|
|
|
// Simplify: and (op x...), (op y...) -> (op (and x, y))
|
|
if (N0.getOpcode() == N1.getOpcode()) {
|
|
SDOperand Tmp = SimplifyBinOpWithSameOpcodeHands(N);
|
|
if (Tmp.Val) return Tmp;
|
|
}
|
|
|
|
// fold (and (sign_extend_inreg x, i16 to i32), 1) -> (and x, 1)
|
|
// fold (and (sra)) -> (and (srl)) when possible.
|
|
if (!MVT::isVector(VT) &&
|
|
SimplifyDemandedBits(SDOperand(N, 0)))
|
|
return SDOperand(N, 0);
|
|
// fold (zext_inreg (extload x)) -> (zextload x)
|
|
if (ISD::isEXTLoad(N0.Val) && ISD::isUNINDEXEDLoad(N0.Val)) {
|
|
LoadSDNode *LN0 = cast<LoadSDNode>(N0);
|
|
MVT::ValueType EVT = LN0->getLoadedVT();
|
|
// If we zero all the possible extended bits, then we can turn this into
|
|
// a zextload if we are running before legalize or the operation is legal.
|
|
if (DAG.MaskedValueIsZero(N1, ~0ULL << MVT::getSizeInBits(EVT)) &&
|
|
(!AfterLegalize || TLI.isLoadXLegal(ISD::ZEXTLOAD, EVT))) {
|
|
SDOperand ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, VT, LN0->getChain(),
|
|
LN0->getBasePtr(), LN0->getSrcValue(),
|
|
LN0->getSrcValueOffset(), EVT,
|
|
LN0->isVolatile(),
|
|
LN0->getAlignment());
|
|
AddToWorkList(N);
|
|
CombineTo(N0.Val, ExtLoad, ExtLoad.getValue(1));
|
|
return SDOperand(N, 0); // Return N so it doesn't get rechecked!
|
|
}
|
|
}
|
|
// fold (zext_inreg (sextload x)) -> (zextload x) iff load has one use
|
|
if (ISD::isSEXTLoad(N0.Val) && ISD::isUNINDEXEDLoad(N0.Val) &&
|
|
N0.hasOneUse()) {
|
|
LoadSDNode *LN0 = cast<LoadSDNode>(N0);
|
|
MVT::ValueType EVT = LN0->getLoadedVT();
|
|
// If we zero all the possible extended bits, then we can turn this into
|
|
// a zextload if we are running before legalize or the operation is legal.
|
|
if (DAG.MaskedValueIsZero(N1, ~0ULL << MVT::getSizeInBits(EVT)) &&
|
|
(!AfterLegalize || TLI.isLoadXLegal(ISD::ZEXTLOAD, EVT))) {
|
|
SDOperand ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, VT, LN0->getChain(),
|
|
LN0->getBasePtr(), LN0->getSrcValue(),
|
|
LN0->getSrcValueOffset(), EVT,
|
|
LN0->isVolatile(),
|
|
LN0->getAlignment());
|
|
AddToWorkList(N);
|
|
CombineTo(N0.Val, ExtLoad, ExtLoad.getValue(1));
|
|
return SDOperand(N, 0); // Return N so it doesn't get rechecked!
|
|
}
|
|
}
|
|
|
|
// fold (and (load x), 255) -> (zextload x, i8)
|
|
// fold (and (extload x, i16), 255) -> (zextload x, i8)
|
|
if (N1C && N0.getOpcode() == ISD::LOAD) {
|
|
LoadSDNode *LN0 = cast<LoadSDNode>(N0);
|
|
if (LN0->getExtensionType() != ISD::SEXTLOAD &&
|
|
LN0->getAddressingMode() == ISD::UNINDEXED &&
|
|
N0.hasOneUse()) {
|
|
MVT::ValueType EVT, LoadedVT;
|
|
if (N1C->getValue() == 255)
|
|
EVT = MVT::i8;
|
|
else if (N1C->getValue() == 65535)
|
|
EVT = MVT::i16;
|
|
else if (N1C->getValue() == ~0U)
|
|
EVT = MVT::i32;
|
|
else
|
|
EVT = MVT::Other;
|
|
|
|
LoadedVT = LN0->getLoadedVT();
|
|
if (EVT != MVT::Other && LoadedVT > EVT &&
|
|
(!AfterLegalize || TLI.isLoadXLegal(ISD::ZEXTLOAD, EVT))) {
|
|
MVT::ValueType PtrType = N0.getOperand(1).getValueType();
|
|
// For big endian targets, we need to add an offset to the pointer to
|
|
// load the correct bytes. For little endian systems, we merely need to
|
|
// read fewer bytes from the same pointer.
|
|
unsigned PtrOff =
|
|
(MVT::getSizeInBits(LoadedVT) - MVT::getSizeInBits(EVT)) / 8;
|
|
SDOperand NewPtr = LN0->getBasePtr();
|
|
if (!TLI.isLittleEndian())
|
|
NewPtr = DAG.getNode(ISD::ADD, PtrType, NewPtr,
|
|
DAG.getConstant(PtrOff, PtrType));
|
|
AddToWorkList(NewPtr.Val);
|
|
SDOperand Load =
|
|
DAG.getExtLoad(ISD::ZEXTLOAD, VT, LN0->getChain(), NewPtr,
|
|
LN0->getSrcValue(), LN0->getSrcValueOffset(), EVT,
|
|
LN0->isVolatile(), LN0->getAlignment());
|
|
AddToWorkList(N);
|
|
CombineTo(N0.Val, Load, Load.getValue(1));
|
|
return SDOperand(N, 0); // Return N so it doesn't get rechecked!
|
|
}
|
|
}
|
|
}
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitOR(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
SDOperand N1 = N->getOperand(1);
|
|
SDOperand LL, LR, RL, RR, CC0, CC1;
|
|
ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
|
|
ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
|
|
MVT::ValueType VT = N1.getValueType();
|
|
unsigned OpSizeInBits = MVT::getSizeInBits(VT);
|
|
|
|
// fold vector ops
|
|
if (MVT::isVector(VT)) {
|
|
SDOperand FoldedVOp = SimplifyVBinOp(N);
|
|
if (FoldedVOp.Val) return FoldedVOp;
|
|
}
|
|
|
|
// fold (or x, undef) -> -1
|
|
if (N0.getOpcode() == ISD::UNDEF || N1.getOpcode() == ISD::UNDEF)
|
|
return DAG.getConstant(~0ULL, VT);
|
|
// fold (or c1, c2) -> c1|c2
|
|
if (N0C && N1C)
|
|
return DAG.getNode(ISD::OR, VT, N0, N1);
|
|
// canonicalize constant to RHS
|
|
if (N0C && !N1C)
|
|
return DAG.getNode(ISD::OR, VT, N1, N0);
|
|
// fold (or x, 0) -> x
|
|
if (N1C && N1C->isNullValue())
|
|
return N0;
|
|
// fold (or x, -1) -> -1
|
|
if (N1C && N1C->isAllOnesValue())
|
|
return N1;
|
|
// fold (or x, c) -> c iff (x & ~c) == 0
|
|
if (N1C &&
|
|
DAG.MaskedValueIsZero(N0,~N1C->getValue() & (~0ULL>>(64-OpSizeInBits))))
|
|
return N1;
|
|
// reassociate or
|
|
SDOperand ROR = ReassociateOps(ISD::OR, N0, N1);
|
|
if (ROR.Val != 0)
|
|
return ROR;
|
|
// Canonicalize (or (and X, c1), c2) -> (and (or X, c2), c1|c2)
|
|
if (N1C && N0.getOpcode() == ISD::AND && N0.Val->hasOneUse() &&
|
|
isa<ConstantSDNode>(N0.getOperand(1))) {
|
|
ConstantSDNode *C1 = cast<ConstantSDNode>(N0.getOperand(1));
|
|
return DAG.getNode(ISD::AND, VT, DAG.getNode(ISD::OR, VT, N0.getOperand(0),
|
|
N1),
|
|
DAG.getConstant(N1C->getValue() | C1->getValue(), VT));
|
|
}
|
|
// fold (or (setcc x), (setcc y)) -> (setcc (or x, y))
|
|
if (isSetCCEquivalent(N0, LL, LR, CC0) && isSetCCEquivalent(N1, RL, RR, CC1)){
|
|
ISD::CondCode Op0 = cast<CondCodeSDNode>(CC0)->get();
|
|
ISD::CondCode Op1 = cast<CondCodeSDNode>(CC1)->get();
|
|
|
|
if (LR == RR && isa<ConstantSDNode>(LR) && Op0 == Op1 &&
|
|
MVT::isInteger(LL.getValueType())) {
|
|
// fold (X != 0) | (Y != 0) -> (X|Y != 0)
|
|
// fold (X < 0) | (Y < 0) -> (X|Y < 0)
|
|
if (cast<ConstantSDNode>(LR)->getValue() == 0 &&
|
|
(Op1 == ISD::SETNE || Op1 == ISD::SETLT)) {
|
|
SDOperand ORNode = DAG.getNode(ISD::OR, LR.getValueType(), LL, RL);
|
|
AddToWorkList(ORNode.Val);
|
|
return DAG.getSetCC(VT, ORNode, LR, Op1);
|
|
}
|
|
// fold (X != -1) | (Y != -1) -> (X&Y != -1)
|
|
// fold (X > -1) | (Y > -1) -> (X&Y > -1)
|
|
if (cast<ConstantSDNode>(LR)->isAllOnesValue() &&
|
|
(Op1 == ISD::SETNE || Op1 == ISD::SETGT)) {
|
|
SDOperand ANDNode = DAG.getNode(ISD::AND, LR.getValueType(), LL, RL);
|
|
AddToWorkList(ANDNode.Val);
|
|
return DAG.getSetCC(VT, ANDNode, LR, Op1);
|
|
}
|
|
}
|
|
// canonicalize equivalent to ll == rl
|
|
if (LL == RR && LR == RL) {
|
|
Op1 = ISD::getSetCCSwappedOperands(Op1);
|
|
std::swap(RL, RR);
|
|
}
|
|
if (LL == RL && LR == RR) {
|
|
bool isInteger = MVT::isInteger(LL.getValueType());
|
|
ISD::CondCode Result = ISD::getSetCCOrOperation(Op0, Op1, isInteger);
|
|
if (Result != ISD::SETCC_INVALID)
|
|
return DAG.getSetCC(N0.getValueType(), LL, LR, Result);
|
|
}
|
|
}
|
|
|
|
// Simplify: or (op x...), (op y...) -> (op (or x, y))
|
|
if (N0.getOpcode() == N1.getOpcode()) {
|
|
SDOperand Tmp = SimplifyBinOpWithSameOpcodeHands(N);
|
|
if (Tmp.Val) return Tmp;
|
|
}
|
|
|
|
// (X & C1) | (Y & C2) -> (X|Y) & C3 if possible.
|
|
if (N0.getOpcode() == ISD::AND &&
|
|
N1.getOpcode() == ISD::AND &&
|
|
N0.getOperand(1).getOpcode() == ISD::Constant &&
|
|
N1.getOperand(1).getOpcode() == ISD::Constant &&
|
|
// Don't increase # computations.
|
|
(N0.Val->hasOneUse() || N1.Val->hasOneUse())) {
|
|
// We can only do this xform if we know that bits from X that are set in C2
|
|
// but not in C1 are already zero. Likewise for Y.
|
|
uint64_t LHSMask = cast<ConstantSDNode>(N0.getOperand(1))->getValue();
|
|
uint64_t RHSMask = cast<ConstantSDNode>(N1.getOperand(1))->getValue();
|
|
|
|
if (DAG.MaskedValueIsZero(N0.getOperand(0), RHSMask&~LHSMask) &&
|
|
DAG.MaskedValueIsZero(N1.getOperand(0), LHSMask&~RHSMask)) {
|
|
SDOperand X =DAG.getNode(ISD::OR, VT, N0.getOperand(0), N1.getOperand(0));
|
|
return DAG.getNode(ISD::AND, VT, X, DAG.getConstant(LHSMask|RHSMask, VT));
|
|
}
|
|
}
|
|
|
|
|
|
// See if this is some rotate idiom.
|
|
if (SDNode *Rot = MatchRotate(N0, N1))
|
|
return SDOperand(Rot, 0);
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
|
|
/// MatchRotateHalf - Match "(X shl/srl V1) & V2" where V2 may not be present.
|
|
static bool MatchRotateHalf(SDOperand Op, SDOperand &Shift, SDOperand &Mask) {
|
|
if (Op.getOpcode() == ISD::AND) {
|
|
if (isa<ConstantSDNode>(Op.getOperand(1))) {
|
|
Mask = Op.getOperand(1);
|
|
Op = Op.getOperand(0);
|
|
} else {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
if (Op.getOpcode() == ISD::SRL || Op.getOpcode() == ISD::SHL) {
|
|
Shift = Op;
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
|
|
// MatchRotate - Handle an 'or' of two operands. If this is one of the many
|
|
// idioms for rotate, and if the target supports rotation instructions, generate
|
|
// a rot[lr].
|
|
SDNode *DAGCombiner::MatchRotate(SDOperand LHS, SDOperand RHS) {
|
|
// Must be a legal type. Expanded an promoted things won't work with rotates.
|
|
MVT::ValueType VT = LHS.getValueType();
|
|
if (!TLI.isTypeLegal(VT)) return 0;
|
|
|
|
// The target must have at least one rotate flavor.
|
|
bool HasROTL = TLI.isOperationLegal(ISD::ROTL, VT);
|
|
bool HasROTR = TLI.isOperationLegal(ISD::ROTR, VT);
|
|
if (!HasROTL && !HasROTR) return 0;
|
|
|
|
// Match "(X shl/srl V1) & V2" where V2 may not be present.
|
|
SDOperand LHSShift; // The shift.
|
|
SDOperand LHSMask; // AND value if any.
|
|
if (!MatchRotateHalf(LHS, LHSShift, LHSMask))
|
|
return 0; // Not part of a rotate.
|
|
|
|
SDOperand RHSShift; // The shift.
|
|
SDOperand RHSMask; // AND value if any.
|
|
if (!MatchRotateHalf(RHS, RHSShift, RHSMask))
|
|
return 0; // Not part of a rotate.
|
|
|
|
if (LHSShift.getOperand(0) != RHSShift.getOperand(0))
|
|
return 0; // Not shifting the same value.
|
|
|
|
if (LHSShift.getOpcode() == RHSShift.getOpcode())
|
|
return 0; // Shifts must disagree.
|
|
|
|
// Canonicalize shl to left side in a shl/srl pair.
|
|
if (RHSShift.getOpcode() == ISD::SHL) {
|
|
std::swap(LHS, RHS);
|
|
std::swap(LHSShift, RHSShift);
|
|
std::swap(LHSMask , RHSMask );
|
|
}
|
|
|
|
unsigned OpSizeInBits = MVT::getSizeInBits(VT);
|
|
SDOperand LHSShiftArg = LHSShift.getOperand(0);
|
|
SDOperand LHSShiftAmt = LHSShift.getOperand(1);
|
|
SDOperand RHSShiftAmt = RHSShift.getOperand(1);
|
|
|
|
// fold (or (shl x, C1), (srl x, C2)) -> (rotl x, C1)
|
|
// fold (or (shl x, C1), (srl x, C2)) -> (rotr x, C2)
|
|
if (LHSShiftAmt.getOpcode() == ISD::Constant &&
|
|
RHSShiftAmt.getOpcode() == ISD::Constant) {
|
|
uint64_t LShVal = cast<ConstantSDNode>(LHSShiftAmt)->getValue();
|
|
uint64_t RShVal = cast<ConstantSDNode>(RHSShiftAmt)->getValue();
|
|
if ((LShVal + RShVal) != OpSizeInBits)
|
|
return 0;
|
|
|
|
SDOperand Rot;
|
|
if (HasROTL)
|
|
Rot = DAG.getNode(ISD::ROTL, VT, LHSShiftArg, LHSShiftAmt);
|
|
else
|
|
Rot = DAG.getNode(ISD::ROTR, VT, LHSShiftArg, RHSShiftAmt);
|
|
|
|
// If there is an AND of either shifted operand, apply it to the result.
|
|
if (LHSMask.Val || RHSMask.Val) {
|
|
uint64_t Mask = MVT::getIntVTBitMask(VT);
|
|
|
|
if (LHSMask.Val) {
|
|
uint64_t RHSBits = (1ULL << LShVal)-1;
|
|
Mask &= cast<ConstantSDNode>(LHSMask)->getValue() | RHSBits;
|
|
}
|
|
if (RHSMask.Val) {
|
|
uint64_t LHSBits = ~((1ULL << (OpSizeInBits-RShVal))-1);
|
|
Mask &= cast<ConstantSDNode>(RHSMask)->getValue() | LHSBits;
|
|
}
|
|
|
|
Rot = DAG.getNode(ISD::AND, VT, Rot, DAG.getConstant(Mask, VT));
|
|
}
|
|
|
|
return Rot.Val;
|
|
}
|
|
|
|
// If there is a mask here, and we have a variable shift, we can't be sure
|
|
// that we're masking out the right stuff.
|
|
if (LHSMask.Val || RHSMask.Val)
|
|
return 0;
|
|
|
|
// fold (or (shl x, y), (srl x, (sub 32, y))) -> (rotl x, y)
|
|
// fold (or (shl x, y), (srl x, (sub 32, y))) -> (rotr x, (sub 32, y))
|
|
if (RHSShiftAmt.getOpcode() == ISD::SUB &&
|
|
LHSShiftAmt == RHSShiftAmt.getOperand(1)) {
|
|
if (ConstantSDNode *SUBC =
|
|
dyn_cast<ConstantSDNode>(RHSShiftAmt.getOperand(0))) {
|
|
if (SUBC->getValue() == OpSizeInBits)
|
|
if (HasROTL)
|
|
return DAG.getNode(ISD::ROTL, VT, LHSShiftArg, LHSShiftAmt).Val;
|
|
else
|
|
return DAG.getNode(ISD::ROTR, VT, LHSShiftArg, RHSShiftAmt).Val;
|
|
}
|
|
}
|
|
|
|
// fold (or (shl x, (sub 32, y)), (srl x, r)) -> (rotr x, y)
|
|
// fold (or (shl x, (sub 32, y)), (srl x, r)) -> (rotl x, (sub 32, y))
|
|
if (LHSShiftAmt.getOpcode() == ISD::SUB &&
|
|
RHSShiftAmt == LHSShiftAmt.getOperand(1)) {
|
|
if (ConstantSDNode *SUBC =
|
|
dyn_cast<ConstantSDNode>(LHSShiftAmt.getOperand(0))) {
|
|
if (SUBC->getValue() == OpSizeInBits)
|
|
if (HasROTL)
|
|
return DAG.getNode(ISD::ROTL, VT, LHSShiftArg, LHSShiftAmt).Val;
|
|
else
|
|
return DAG.getNode(ISD::ROTR, VT, LHSShiftArg, RHSShiftAmt).Val;
|
|
}
|
|
}
|
|
|
|
// Look for sign/zext/any-extended cases:
|
|
if ((LHSShiftAmt.getOpcode() == ISD::SIGN_EXTEND
|
|
|| LHSShiftAmt.getOpcode() == ISD::ZERO_EXTEND
|
|
|| LHSShiftAmt.getOpcode() == ISD::ANY_EXTEND) &&
|
|
(RHSShiftAmt.getOpcode() == ISD::SIGN_EXTEND
|
|
|| RHSShiftAmt.getOpcode() == ISD::ZERO_EXTEND
|
|
|| RHSShiftAmt.getOpcode() == ISD::ANY_EXTEND)) {
|
|
SDOperand LExtOp0 = LHSShiftAmt.getOperand(0);
|
|
SDOperand RExtOp0 = RHSShiftAmt.getOperand(0);
|
|
if (RExtOp0.getOpcode() == ISD::SUB &&
|
|
RExtOp0.getOperand(1) == LExtOp0) {
|
|
// fold (or (shl x, (*ext y)), (srl x, (*ext (sub 32, y)))) ->
|
|
// (rotr x, y)
|
|
// fold (or (shl x, (*ext y)), (srl x, (*ext (sub 32, y)))) ->
|
|
// (rotl x, (sub 32, y))
|
|
if (ConstantSDNode *SUBC = cast<ConstantSDNode>(RExtOp0.getOperand(0))) {
|
|
if (SUBC->getValue() == OpSizeInBits) {
|
|
if (HasROTL)
|
|
return DAG.getNode(ISD::ROTL, VT, LHSShiftArg, LHSShiftAmt).Val;
|
|
else
|
|
return DAG.getNode(ISD::ROTR, VT, LHSShiftArg, RHSShiftAmt).Val;
|
|
}
|
|
}
|
|
} else if (LExtOp0.getOpcode() == ISD::SUB &&
|
|
RExtOp0 == LExtOp0.getOperand(1)) {
|
|
// fold (or (shl x, (*ext (sub 32, y))), (srl x, (*ext r))) ->
|
|
// (rotl x, y)
|
|
// fold (or (shl x, (*ext (sub 32, y))), (srl x, (*ext r))) ->
|
|
// (rotr x, (sub 32, y))
|
|
if (ConstantSDNode *SUBC = cast<ConstantSDNode>(LExtOp0.getOperand(0))) {
|
|
if (SUBC->getValue() == OpSizeInBits) {
|
|
if (HasROTL)
|
|
return DAG.getNode(ISD::ROTL, VT, LHSShiftArg, RHSShiftAmt).Val;
|
|
else
|
|
return DAG.getNode(ISD::ROTL, VT, LHSShiftArg, LHSShiftAmt).Val;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
SDOperand DAGCombiner::visitXOR(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
SDOperand N1 = N->getOperand(1);
|
|
SDOperand LHS, RHS, CC;
|
|
ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
|
|
ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
|
|
MVT::ValueType VT = N0.getValueType();
|
|
|
|
// fold vector ops
|
|
if (MVT::isVector(VT)) {
|
|
SDOperand FoldedVOp = SimplifyVBinOp(N);
|
|
if (FoldedVOp.Val) return FoldedVOp;
|
|
}
|
|
|
|
// fold (xor x, undef) -> undef
|
|
if (N0.getOpcode() == ISD::UNDEF)
|
|
return N0;
|
|
if (N1.getOpcode() == ISD::UNDEF)
|
|
return N1;
|
|
// fold (xor c1, c2) -> c1^c2
|
|
if (N0C && N1C)
|
|
return DAG.getNode(ISD::XOR, VT, N0, N1);
|
|
// canonicalize constant to RHS
|
|
if (N0C && !N1C)
|
|
return DAG.getNode(ISD::XOR, VT, N1, N0);
|
|
// fold (xor x, 0) -> x
|
|
if (N1C && N1C->isNullValue())
|
|
return N0;
|
|
// reassociate xor
|
|
SDOperand RXOR = ReassociateOps(ISD::XOR, N0, N1);
|
|
if (RXOR.Val != 0)
|
|
return RXOR;
|
|
// fold !(x cc y) -> (x !cc y)
|
|
if (N1C && N1C->getValue() == 1 && isSetCCEquivalent(N0, LHS, RHS, CC)) {
|
|
bool isInt = MVT::isInteger(LHS.getValueType());
|
|
ISD::CondCode NotCC = ISD::getSetCCInverse(cast<CondCodeSDNode>(CC)->get(),
|
|
isInt);
|
|
if (N0.getOpcode() == ISD::SETCC)
|
|
return DAG.getSetCC(VT, LHS, RHS, NotCC);
|
|
if (N0.getOpcode() == ISD::SELECT_CC)
|
|
return DAG.getSelectCC(LHS, RHS, N0.getOperand(2),N0.getOperand(3),NotCC);
|
|
assert(0 && "Unhandled SetCC Equivalent!");
|
|
abort();
|
|
}
|
|
// fold (not (zext (setcc x, y))) -> (zext (not (setcc x, y)))
|
|
if (N1C && N1C->getValue() == 1 && N0.getOpcode() == ISD::ZERO_EXTEND &&
|
|
N0.Val->hasOneUse() && isSetCCEquivalent(N0.getOperand(0), LHS, RHS, CC)){
|
|
SDOperand V = N0.getOperand(0);
|
|
V = DAG.getNode(ISD::XOR, V.getValueType(), V,
|
|
DAG.getConstant(1, V.getValueType()));
|
|
AddToWorkList(V.Val);
|
|
return DAG.getNode(ISD::ZERO_EXTEND, VT, V);
|
|
}
|
|
|
|
// fold !(x or y) -> (!x and !y) iff x or y are setcc
|
|
if (N1C && N1C->getValue() == 1 && VT == MVT::i1 &&
|
|
(N0.getOpcode() == ISD::OR || N0.getOpcode() == ISD::AND)) {
|
|
SDOperand LHS = N0.getOperand(0), RHS = N0.getOperand(1);
|
|
if (isOneUseSetCC(RHS) || isOneUseSetCC(LHS)) {
|
|
unsigned NewOpcode = N0.getOpcode() == ISD::AND ? ISD::OR : ISD::AND;
|
|
LHS = DAG.getNode(ISD::XOR, VT, LHS, N1); // RHS = ~LHS
|
|
RHS = DAG.getNode(ISD::XOR, VT, RHS, N1); // RHS = ~RHS
|
|
AddToWorkList(LHS.Val); AddToWorkList(RHS.Val);
|
|
return DAG.getNode(NewOpcode, VT, LHS, RHS);
|
|
}
|
|
}
|
|
// fold !(x or y) -> (!x and !y) iff x or y are constants
|
|
if (N1C && N1C->isAllOnesValue() &&
|
|
(N0.getOpcode() == ISD::OR || N0.getOpcode() == ISD::AND)) {
|
|
SDOperand LHS = N0.getOperand(0), RHS = N0.getOperand(1);
|
|
if (isa<ConstantSDNode>(RHS) || isa<ConstantSDNode>(LHS)) {
|
|
unsigned NewOpcode = N0.getOpcode() == ISD::AND ? ISD::OR : ISD::AND;
|
|
LHS = DAG.getNode(ISD::XOR, VT, LHS, N1); // RHS = ~LHS
|
|
RHS = DAG.getNode(ISD::XOR, VT, RHS, N1); // RHS = ~RHS
|
|
AddToWorkList(LHS.Val); AddToWorkList(RHS.Val);
|
|
return DAG.getNode(NewOpcode, VT, LHS, RHS);
|
|
}
|
|
}
|
|
// fold (xor (xor x, c1), c2) -> (xor x, c1^c2)
|
|
if (N1C && N0.getOpcode() == ISD::XOR) {
|
|
ConstantSDNode *N00C = dyn_cast<ConstantSDNode>(N0.getOperand(0));
|
|
ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
|
|
if (N00C)
|
|
return DAG.getNode(ISD::XOR, VT, N0.getOperand(1),
|
|
DAG.getConstant(N1C->getValue()^N00C->getValue(), VT));
|
|
if (N01C)
|
|
return DAG.getNode(ISD::XOR, VT, N0.getOperand(0),
|
|
DAG.getConstant(N1C->getValue()^N01C->getValue(), VT));
|
|
}
|
|
// fold (xor x, x) -> 0
|
|
if (N0 == N1) {
|
|
if (!MVT::isVector(VT)) {
|
|
return DAG.getConstant(0, VT);
|
|
} else if (!AfterLegalize || TLI.isOperationLegal(ISD::BUILD_VECTOR, VT)) {
|
|
// Produce a vector of zeros.
|
|
SDOperand El = DAG.getConstant(0, MVT::getVectorElementType(VT));
|
|
std::vector<SDOperand> Ops(MVT::getVectorNumElements(VT), El);
|
|
return DAG.getNode(ISD::BUILD_VECTOR, VT, &Ops[0], Ops.size());
|
|
}
|
|
}
|
|
|
|
// Simplify: xor (op x...), (op y...) -> (op (xor x, y))
|
|
if (N0.getOpcode() == N1.getOpcode()) {
|
|
SDOperand Tmp = SimplifyBinOpWithSameOpcodeHands(N);
|
|
if (Tmp.Val) return Tmp;
|
|
}
|
|
|
|
// Simplify the expression using non-local knowledge.
|
|
if (!MVT::isVector(VT) &&
|
|
SimplifyDemandedBits(SDOperand(N, 0)))
|
|
return SDOperand(N, 0);
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitSHL(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
SDOperand N1 = N->getOperand(1);
|
|
ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
|
|
ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
|
|
MVT::ValueType VT = N0.getValueType();
|
|
unsigned OpSizeInBits = MVT::getSizeInBits(VT);
|
|
|
|
// fold (shl c1, c2) -> c1<<c2
|
|
if (N0C && N1C)
|
|
return DAG.getNode(ISD::SHL, VT, N0, N1);
|
|
// fold (shl 0, x) -> 0
|
|
if (N0C && N0C->isNullValue())
|
|
return N0;
|
|
// fold (shl x, c >= size(x)) -> undef
|
|
if (N1C && N1C->getValue() >= OpSizeInBits)
|
|
return DAG.getNode(ISD::UNDEF, VT);
|
|
// fold (shl x, 0) -> x
|
|
if (N1C && N1C->isNullValue())
|
|
return N0;
|
|
// if (shl x, c) is known to be zero, return 0
|
|
if (DAG.MaskedValueIsZero(SDOperand(N, 0), MVT::getIntVTBitMask(VT)))
|
|
return DAG.getConstant(0, VT);
|
|
if (N1C && SimplifyDemandedBits(SDOperand(N, 0)))
|
|
return SDOperand(N, 0);
|
|
// fold (shl (shl x, c1), c2) -> 0 or (shl x, c1+c2)
|
|
if (N1C && N0.getOpcode() == ISD::SHL &&
|
|
N0.getOperand(1).getOpcode() == ISD::Constant) {
|
|
uint64_t c1 = cast<ConstantSDNode>(N0.getOperand(1))->getValue();
|
|
uint64_t c2 = N1C->getValue();
|
|
if (c1 + c2 > OpSizeInBits)
|
|
return DAG.getConstant(0, VT);
|
|
return DAG.getNode(ISD::SHL, VT, N0.getOperand(0),
|
|
DAG.getConstant(c1 + c2, N1.getValueType()));
|
|
}
|
|
// fold (shl (srl x, c1), c2) -> (shl (and x, -1 << c1), c2-c1) or
|
|
// (srl (and x, -1 << c1), c1-c2)
|
|
if (N1C && N0.getOpcode() == ISD::SRL &&
|
|
N0.getOperand(1).getOpcode() == ISD::Constant) {
|
|
uint64_t c1 = cast<ConstantSDNode>(N0.getOperand(1))->getValue();
|
|
uint64_t c2 = N1C->getValue();
|
|
SDOperand Mask = DAG.getNode(ISD::AND, VT, N0.getOperand(0),
|
|
DAG.getConstant(~0ULL << c1, VT));
|
|
if (c2 > c1)
|
|
return DAG.getNode(ISD::SHL, VT, Mask,
|
|
DAG.getConstant(c2-c1, N1.getValueType()));
|
|
else
|
|
return DAG.getNode(ISD::SRL, VT, Mask,
|
|
DAG.getConstant(c1-c2, N1.getValueType()));
|
|
}
|
|
// fold (shl (sra x, c1), c1) -> (and x, -1 << c1)
|
|
if (N1C && N0.getOpcode() == ISD::SRA && N1 == N0.getOperand(1))
|
|
return DAG.getNode(ISD::AND, VT, N0.getOperand(0),
|
|
DAG.getConstant(~0ULL << N1C->getValue(), VT));
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitSRA(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
SDOperand N1 = N->getOperand(1);
|
|
ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
|
|
ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
|
|
MVT::ValueType VT = N0.getValueType();
|
|
|
|
// fold (sra c1, c2) -> c1>>c2
|
|
if (N0C && N1C)
|
|
return DAG.getNode(ISD::SRA, VT, N0, N1);
|
|
// fold (sra 0, x) -> 0
|
|
if (N0C && N0C->isNullValue())
|
|
return N0;
|
|
// fold (sra -1, x) -> -1
|
|
if (N0C && N0C->isAllOnesValue())
|
|
return N0;
|
|
// fold (sra x, c >= size(x)) -> undef
|
|
if (N1C && N1C->getValue() >= MVT::getSizeInBits(VT))
|
|
return DAG.getNode(ISD::UNDEF, VT);
|
|
// fold (sra x, 0) -> x
|
|
if (N1C && N1C->isNullValue())
|
|
return N0;
|
|
// fold (sra (shl x, c1), c1) -> sext_inreg for some c1 and target supports
|
|
// sext_inreg.
|
|
if (N1C && N0.getOpcode() == ISD::SHL && N1 == N0.getOperand(1)) {
|
|
unsigned LowBits = MVT::getSizeInBits(VT) - (unsigned)N1C->getValue();
|
|
MVT::ValueType EVT;
|
|
switch (LowBits) {
|
|
default: EVT = MVT::Other; break;
|
|
case 1: EVT = MVT::i1; break;
|
|
case 8: EVT = MVT::i8; break;
|
|
case 16: EVT = MVT::i16; break;
|
|
case 32: EVT = MVT::i32; break;
|
|
}
|
|
if (EVT > MVT::Other && TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG, EVT))
|
|
return DAG.getNode(ISD::SIGN_EXTEND_INREG, VT, N0.getOperand(0),
|
|
DAG.getValueType(EVT));
|
|
}
|
|
|
|
// fold (sra (sra x, c1), c2) -> (sra x, c1+c2)
|
|
if (N1C && N0.getOpcode() == ISD::SRA) {
|
|
if (ConstantSDNode *C1 = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
|
|
unsigned Sum = N1C->getValue() + C1->getValue();
|
|
if (Sum >= MVT::getSizeInBits(VT)) Sum = MVT::getSizeInBits(VT)-1;
|
|
return DAG.getNode(ISD::SRA, VT, N0.getOperand(0),
|
|
DAG.getConstant(Sum, N1C->getValueType(0)));
|
|
}
|
|
}
|
|
|
|
// Simplify, based on bits shifted out of the LHS.
|
|
if (N1C && SimplifyDemandedBits(SDOperand(N, 0)))
|
|
return SDOperand(N, 0);
|
|
|
|
|
|
// If the sign bit is known to be zero, switch this to a SRL.
|
|
if (DAG.MaskedValueIsZero(N0, MVT::getIntVTSignBit(VT)))
|
|
return DAG.getNode(ISD::SRL, VT, N0, N1);
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitSRL(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
SDOperand N1 = N->getOperand(1);
|
|
ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
|
|
ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
|
|
MVT::ValueType VT = N0.getValueType();
|
|
unsigned OpSizeInBits = MVT::getSizeInBits(VT);
|
|
|
|
// fold (srl c1, c2) -> c1 >>u c2
|
|
if (N0C && N1C)
|
|
return DAG.getNode(ISD::SRL, VT, N0, N1);
|
|
// fold (srl 0, x) -> 0
|
|
if (N0C && N0C->isNullValue())
|
|
return N0;
|
|
// fold (srl x, c >= size(x)) -> undef
|
|
if (N1C && N1C->getValue() >= OpSizeInBits)
|
|
return DAG.getNode(ISD::UNDEF, VT);
|
|
// fold (srl x, 0) -> x
|
|
if (N1C && N1C->isNullValue())
|
|
return N0;
|
|
// if (srl x, c) is known to be zero, return 0
|
|
if (N1C && DAG.MaskedValueIsZero(SDOperand(N, 0), ~0ULL >> (64-OpSizeInBits)))
|
|
return DAG.getConstant(0, VT);
|
|
|
|
// fold (srl (srl x, c1), c2) -> 0 or (srl x, c1+c2)
|
|
if (N1C && N0.getOpcode() == ISD::SRL &&
|
|
N0.getOperand(1).getOpcode() == ISD::Constant) {
|
|
uint64_t c1 = cast<ConstantSDNode>(N0.getOperand(1))->getValue();
|
|
uint64_t c2 = N1C->getValue();
|
|
if (c1 + c2 > OpSizeInBits)
|
|
return DAG.getConstant(0, VT);
|
|
return DAG.getNode(ISD::SRL, VT, N0.getOperand(0),
|
|
DAG.getConstant(c1 + c2, N1.getValueType()));
|
|
}
|
|
|
|
// fold (srl (anyextend x), c) -> (anyextend (srl x, c))
|
|
if (N1C && N0.getOpcode() == ISD::ANY_EXTEND) {
|
|
// Shifting in all undef bits?
|
|
MVT::ValueType SmallVT = N0.getOperand(0).getValueType();
|
|
if (N1C->getValue() >= MVT::getSizeInBits(SmallVT))
|
|
return DAG.getNode(ISD::UNDEF, VT);
|
|
|
|
SDOperand SmallShift = DAG.getNode(ISD::SRL, SmallVT, N0.getOperand(0), N1);
|
|
AddToWorkList(SmallShift.Val);
|
|
return DAG.getNode(ISD::ANY_EXTEND, VT, SmallShift);
|
|
}
|
|
|
|
// fold (srl (sra X, Y), 31) -> (srl X, 31). This srl only looks at the sign
|
|
// bit, which is unmodified by sra.
|
|
if (N1C && N1C->getValue()+1 == MVT::getSizeInBits(VT)) {
|
|
if (N0.getOpcode() == ISD::SRA)
|
|
return DAG.getNode(ISD::SRL, VT, N0.getOperand(0), N1);
|
|
}
|
|
|
|
// fold (srl (ctlz x), "5") -> x iff x has one bit set (the low bit).
|
|
if (N1C && N0.getOpcode() == ISD::CTLZ &&
|
|
N1C->getValue() == Log2_32(MVT::getSizeInBits(VT))) {
|
|
uint64_t KnownZero, KnownOne, Mask = MVT::getIntVTBitMask(VT);
|
|
DAG.ComputeMaskedBits(N0.getOperand(0), Mask, KnownZero, KnownOne);
|
|
|
|
// If any of the input bits are KnownOne, then the input couldn't be all
|
|
// zeros, thus the result of the srl will always be zero.
|
|
if (KnownOne) return DAG.getConstant(0, VT);
|
|
|
|
// If all of the bits input the to ctlz node are known to be zero, then
|
|
// the result of the ctlz is "32" and the result of the shift is one.
|
|
uint64_t UnknownBits = ~KnownZero & Mask;
|
|
if (UnknownBits == 0) return DAG.getConstant(1, VT);
|
|
|
|
// Otherwise, check to see if there is exactly one bit input to the ctlz.
|
|
if ((UnknownBits & (UnknownBits-1)) == 0) {
|
|
// Okay, we know that only that the single bit specified by UnknownBits
|
|
// could be set on input to the CTLZ node. If this bit is set, the SRL
|
|
// will return 0, if it is clear, it returns 1. Change the CTLZ/SRL pair
|
|
// to an SRL,XOR pair, which is likely to simplify more.
|
|
unsigned ShAmt = CountTrailingZeros_64(UnknownBits);
|
|
SDOperand Op = N0.getOperand(0);
|
|
if (ShAmt) {
|
|
Op = DAG.getNode(ISD::SRL, VT, Op,
|
|
DAG.getConstant(ShAmt, TLI.getShiftAmountTy()));
|
|
AddToWorkList(Op.Val);
|
|
}
|
|
return DAG.getNode(ISD::XOR, VT, Op, DAG.getConstant(1, VT));
|
|
}
|
|
}
|
|
|
|
// fold operands of srl based on knowledge that the low bits are not
|
|
// demanded.
|
|
if (N1C && SimplifyDemandedBits(SDOperand(N, 0)))
|
|
return SDOperand(N, 0);
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitCTLZ(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
MVT::ValueType VT = N->getValueType(0);
|
|
|
|
// fold (ctlz c1) -> c2
|
|
if (isa<ConstantSDNode>(N0))
|
|
return DAG.getNode(ISD::CTLZ, VT, N0);
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitCTTZ(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
MVT::ValueType VT = N->getValueType(0);
|
|
|
|
// fold (cttz c1) -> c2
|
|
if (isa<ConstantSDNode>(N0))
|
|
return DAG.getNode(ISD::CTTZ, VT, N0);
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitCTPOP(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
MVT::ValueType VT = N->getValueType(0);
|
|
|
|
// fold (ctpop c1) -> c2
|
|
if (isa<ConstantSDNode>(N0))
|
|
return DAG.getNode(ISD::CTPOP, VT, N0);
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitSELECT(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
SDOperand N1 = N->getOperand(1);
|
|
SDOperand N2 = N->getOperand(2);
|
|
ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
|
|
ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
|
|
ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2);
|
|
MVT::ValueType VT = N->getValueType(0);
|
|
MVT::ValueType VT0 = N0.getValueType();
|
|
|
|
// fold select C, X, X -> X
|
|
if (N1 == N2)
|
|
return N1;
|
|
// fold select true, X, Y -> X
|
|
if (N0C && !N0C->isNullValue())
|
|
return N1;
|
|
// fold select false, X, Y -> Y
|
|
if (N0C && N0C->isNullValue())
|
|
return N2;
|
|
// fold select C, 1, X -> C | X
|
|
if (MVT::i1 == VT && N1C && N1C->getValue() == 1)
|
|
return DAG.getNode(ISD::OR, VT, N0, N2);
|
|
// fold select C, 0, 1 -> ~C
|
|
if (MVT::isInteger(VT) && MVT::isInteger(VT0) &&
|
|
N1C && N2C && N1C->isNullValue() && N2C->getValue() == 1) {
|
|
SDOperand XORNode = DAG.getNode(ISD::XOR, VT0, N0, DAG.getConstant(1, VT0));
|
|
if (VT == VT0)
|
|
return XORNode;
|
|
AddToWorkList(XORNode.Val);
|
|
if (MVT::getSizeInBits(VT) > MVT::getSizeInBits(VT0))
|
|
return DAG.getNode(ISD::ZERO_EXTEND, VT, XORNode);
|
|
return DAG.getNode(ISD::TRUNCATE, VT, XORNode);
|
|
}
|
|
// fold select C, 0, X -> ~C & X
|
|
if (VT == VT0 && N1C && N1C->isNullValue()) {
|
|
SDOperand XORNode = DAG.getNode(ISD::XOR, VT, N0, DAG.getConstant(1, VT));
|
|
AddToWorkList(XORNode.Val);
|
|
return DAG.getNode(ISD::AND, VT, XORNode, N2);
|
|
}
|
|
// fold select C, X, 1 -> ~C | X
|
|
if (VT == VT0 && N2C && N2C->getValue() == 1) {
|
|
SDOperand XORNode = DAG.getNode(ISD::XOR, VT, N0, DAG.getConstant(1, VT));
|
|
AddToWorkList(XORNode.Val);
|
|
return DAG.getNode(ISD::OR, VT, XORNode, N1);
|
|
}
|
|
// fold select C, X, 0 -> C & X
|
|
// FIXME: this should check for C type == X type, not i1?
|
|
if (MVT::i1 == VT && N2C && N2C->isNullValue())
|
|
return DAG.getNode(ISD::AND, VT, N0, N1);
|
|
// fold X ? X : Y --> X ? 1 : Y --> X | Y
|
|
if (MVT::i1 == VT && N0 == N1)
|
|
return DAG.getNode(ISD::OR, VT, N0, N2);
|
|
// fold X ? Y : X --> X ? Y : 0 --> X & Y
|
|
if (MVT::i1 == VT && N0 == N2)
|
|
return DAG.getNode(ISD::AND, VT, N0, N1);
|
|
|
|
// If we can fold this based on the true/false value, do so.
|
|
if (SimplifySelectOps(N, N1, N2))
|
|
return SDOperand(N, 0); // Don't revisit N.
|
|
|
|
// fold selects based on a setcc into other things, such as min/max/abs
|
|
if (N0.getOpcode() == ISD::SETCC)
|
|
// FIXME:
|
|
// Check against MVT::Other for SELECT_CC, which is a workaround for targets
|
|
// having to say they don't support SELECT_CC on every type the DAG knows
|
|
// about, since there is no way to mark an opcode illegal at all value types
|
|
if (TLI.isOperationLegal(ISD::SELECT_CC, MVT::Other))
|
|
return DAG.getNode(ISD::SELECT_CC, VT, N0.getOperand(0), N0.getOperand(1),
|
|
N1, N2, N0.getOperand(2));
|
|
else
|
|
return SimplifySelect(N0, N1, N2);
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitSELECT_CC(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
SDOperand N1 = N->getOperand(1);
|
|
SDOperand N2 = N->getOperand(2);
|
|
SDOperand N3 = N->getOperand(3);
|
|
SDOperand N4 = N->getOperand(4);
|
|
ISD::CondCode CC = cast<CondCodeSDNode>(N4)->get();
|
|
|
|
// fold select_cc lhs, rhs, x, x, cc -> x
|
|
if (N2 == N3)
|
|
return N2;
|
|
|
|
// Determine if the condition we're dealing with is constant
|
|
SDOperand SCC = SimplifySetCC(TLI.getSetCCResultTy(), N0, N1, CC, false);
|
|
if (SCC.Val) AddToWorkList(SCC.Val);
|
|
|
|
if (ConstantSDNode *SCCC = dyn_cast_or_null<ConstantSDNode>(SCC.Val)) {
|
|
if (SCCC->getValue())
|
|
return N2; // cond always true -> true val
|
|
else
|
|
return N3; // cond always false -> false val
|
|
}
|
|
|
|
// Fold to a simpler select_cc
|
|
if (SCC.Val && SCC.getOpcode() == ISD::SETCC)
|
|
return DAG.getNode(ISD::SELECT_CC, N2.getValueType(),
|
|
SCC.getOperand(0), SCC.getOperand(1), N2, N3,
|
|
SCC.getOperand(2));
|
|
|
|
// If we can fold this based on the true/false value, do so.
|
|
if (SimplifySelectOps(N, N2, N3))
|
|
return SDOperand(N, 0); // Don't revisit N.
|
|
|
|
// fold select_cc into other things, such as min/max/abs
|
|
return SimplifySelectCC(N0, N1, N2, N3, CC);
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitSETCC(SDNode *N) {
|
|
return SimplifySetCC(N->getValueType(0), N->getOperand(0), N->getOperand(1),
|
|
cast<CondCodeSDNode>(N->getOperand(2))->get());
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitSIGN_EXTEND(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
MVT::ValueType VT = N->getValueType(0);
|
|
|
|
// fold (sext c1) -> c1
|
|
if (isa<ConstantSDNode>(N0))
|
|
return DAG.getNode(ISD::SIGN_EXTEND, VT, N0);
|
|
|
|
// fold (sext (sext x)) -> (sext x)
|
|
// fold (sext (aext x)) -> (sext x)
|
|
if (N0.getOpcode() == ISD::SIGN_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND)
|
|
return DAG.getNode(ISD::SIGN_EXTEND, VT, N0.getOperand(0));
|
|
|
|
// fold (sext (truncate (load x))) -> (sext (smaller load x))
|
|
// fold (sext (truncate (srl (load x), c))) -> (sext (smaller load (x+c/n)))
|
|
if (N0.getOpcode() == ISD::TRUNCATE) {
|
|
SDOperand NarrowLoad = ReduceLoadWidth(N0.Val);
|
|
if (NarrowLoad.Val) {
|
|
if (NarrowLoad.Val != N0.Val)
|
|
CombineTo(N0.Val, NarrowLoad);
|
|
return DAG.getNode(ISD::SIGN_EXTEND, VT, NarrowLoad);
|
|
}
|
|
}
|
|
|
|
// See if the value being truncated is already sign extended. If so, just
|
|
// eliminate the trunc/sext pair.
|
|
if (N0.getOpcode() == ISD::TRUNCATE) {
|
|
SDOperand Op = N0.getOperand(0);
|
|
unsigned OpBits = MVT::getSizeInBits(Op.getValueType());
|
|
unsigned MidBits = MVT::getSizeInBits(N0.getValueType());
|
|
unsigned DestBits = MVT::getSizeInBits(VT);
|
|
unsigned NumSignBits = DAG.ComputeNumSignBits(Op);
|
|
|
|
if (OpBits == DestBits) {
|
|
// Op is i32, Mid is i8, and Dest is i32. If Op has more than 24 sign
|
|
// bits, it is already ready.
|
|
if (NumSignBits > DestBits-MidBits)
|
|
return Op;
|
|
} else if (OpBits < DestBits) {
|
|
// Op is i32, Mid is i8, and Dest is i64. If Op has more than 24 sign
|
|
// bits, just sext from i32.
|
|
if (NumSignBits > OpBits-MidBits)
|
|
return DAG.getNode(ISD::SIGN_EXTEND, VT, Op);
|
|
} else {
|
|
// Op is i64, Mid is i8, and Dest is i32. If Op has more than 56 sign
|
|
// bits, just truncate to i32.
|
|
if (NumSignBits > OpBits-MidBits)
|
|
return DAG.getNode(ISD::TRUNCATE, VT, Op);
|
|
}
|
|
|
|
// fold (sext (truncate x)) -> (sextinreg x).
|
|
if (!AfterLegalize || TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG,
|
|
N0.getValueType())) {
|
|
if (Op.getValueType() < VT)
|
|
Op = DAG.getNode(ISD::ANY_EXTEND, VT, Op);
|
|
else if (Op.getValueType() > VT)
|
|
Op = DAG.getNode(ISD::TRUNCATE, VT, Op);
|
|
return DAG.getNode(ISD::SIGN_EXTEND_INREG, VT, Op,
|
|
DAG.getValueType(N0.getValueType()));
|
|
}
|
|
}
|
|
|
|
// fold (sext (load x)) -> (sext (truncate (sextload x)))
|
|
if (ISD::isNON_EXTLoad(N0.Val) && N0.hasOneUse() &&
|
|
(!AfterLegalize||TLI.isLoadXLegal(ISD::SEXTLOAD, N0.getValueType()))){
|
|
LoadSDNode *LN0 = cast<LoadSDNode>(N0);
|
|
SDOperand ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, VT, LN0->getChain(),
|
|
LN0->getBasePtr(), LN0->getSrcValue(),
|
|
LN0->getSrcValueOffset(),
|
|
N0.getValueType(),
|
|
LN0->isVolatile(),
|
|
LN0->getAlignment());
|
|
CombineTo(N, ExtLoad);
|
|
CombineTo(N0.Val, DAG.getNode(ISD::TRUNCATE, N0.getValueType(), ExtLoad),
|
|
ExtLoad.getValue(1));
|
|
return SDOperand(N, 0); // Return N so it doesn't get rechecked!
|
|
}
|
|
|
|
// fold (sext (sextload x)) -> (sext (truncate (sextload x)))
|
|
// fold (sext ( extload x)) -> (sext (truncate (sextload x)))
|
|
if ((ISD::isSEXTLoad(N0.Val) || ISD::isEXTLoad(N0.Val)) &&
|
|
ISD::isUNINDEXEDLoad(N0.Val) && N0.hasOneUse()) {
|
|
LoadSDNode *LN0 = cast<LoadSDNode>(N0);
|
|
MVT::ValueType EVT = LN0->getLoadedVT();
|
|
if (!AfterLegalize || TLI.isLoadXLegal(ISD::SEXTLOAD, EVT)) {
|
|
SDOperand ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, VT, LN0->getChain(),
|
|
LN0->getBasePtr(), LN0->getSrcValue(),
|
|
LN0->getSrcValueOffset(), EVT,
|
|
LN0->isVolatile(),
|
|
LN0->getAlignment());
|
|
CombineTo(N, ExtLoad);
|
|
CombineTo(N0.Val, DAG.getNode(ISD::TRUNCATE, N0.getValueType(), ExtLoad),
|
|
ExtLoad.getValue(1));
|
|
return SDOperand(N, 0); // Return N so it doesn't get rechecked!
|
|
}
|
|
}
|
|
|
|
// sext(setcc x,y,cc) -> select_cc x, y, -1, 0, cc
|
|
if (N0.getOpcode() == ISD::SETCC) {
|
|
SDOperand SCC =
|
|
SimplifySelectCC(N0.getOperand(0), N0.getOperand(1),
|
|
DAG.getConstant(~0ULL, VT), DAG.getConstant(0, VT),
|
|
cast<CondCodeSDNode>(N0.getOperand(2))->get(), true);
|
|
if (SCC.Val) return SCC;
|
|
}
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitZERO_EXTEND(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
MVT::ValueType VT = N->getValueType(0);
|
|
|
|
// fold (zext c1) -> c1
|
|
if (isa<ConstantSDNode>(N0))
|
|
return DAG.getNode(ISD::ZERO_EXTEND, VT, N0);
|
|
// fold (zext (zext x)) -> (zext x)
|
|
// fold (zext (aext x)) -> (zext x)
|
|
if (N0.getOpcode() == ISD::ZERO_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND)
|
|
return DAG.getNode(ISD::ZERO_EXTEND, VT, N0.getOperand(0));
|
|
|
|
// fold (zext (truncate (load x))) -> (zext (smaller load x))
|
|
// fold (zext (truncate (srl (load x), c))) -> (zext (small load (x+c/n)))
|
|
if (N0.getOpcode() == ISD::TRUNCATE) {
|
|
SDOperand NarrowLoad = ReduceLoadWidth(N0.Val);
|
|
if (NarrowLoad.Val) {
|
|
if (NarrowLoad.Val != N0.Val)
|
|
CombineTo(N0.Val, NarrowLoad);
|
|
return DAG.getNode(ISD::ZERO_EXTEND, VT, NarrowLoad);
|
|
}
|
|
}
|
|
|
|
// fold (zext (truncate x)) -> (and x, mask)
|
|
if (N0.getOpcode() == ISD::TRUNCATE &&
|
|
(!AfterLegalize || TLI.isOperationLegal(ISD::AND, VT))) {
|
|
SDOperand Op = N0.getOperand(0);
|
|
if (Op.getValueType() < VT) {
|
|
Op = DAG.getNode(ISD::ANY_EXTEND, VT, Op);
|
|
} else if (Op.getValueType() > VT) {
|
|
Op = DAG.getNode(ISD::TRUNCATE, VT, Op);
|
|
}
|
|
return DAG.getZeroExtendInReg(Op, N0.getValueType());
|
|
}
|
|
|
|
// fold (zext (and (trunc x), cst)) -> (and x, cst).
|
|
if (N0.getOpcode() == ISD::AND &&
|
|
N0.getOperand(0).getOpcode() == ISD::TRUNCATE &&
|
|
N0.getOperand(1).getOpcode() == ISD::Constant) {
|
|
SDOperand X = N0.getOperand(0).getOperand(0);
|
|
if (X.getValueType() < VT) {
|
|
X = DAG.getNode(ISD::ANY_EXTEND, VT, X);
|
|
} else if (X.getValueType() > VT) {
|
|
X = DAG.getNode(ISD::TRUNCATE, VT, X);
|
|
}
|
|
uint64_t Mask = cast<ConstantSDNode>(N0.getOperand(1))->getValue();
|
|
return DAG.getNode(ISD::AND, VT, X, DAG.getConstant(Mask, VT));
|
|
}
|
|
|
|
// fold (zext (load x)) -> (zext (truncate (zextload x)))
|
|
if (ISD::isNON_EXTLoad(N0.Val) && N0.hasOneUse() &&
|
|
(!AfterLegalize||TLI.isLoadXLegal(ISD::ZEXTLOAD, N0.getValueType()))) {
|
|
LoadSDNode *LN0 = cast<LoadSDNode>(N0);
|
|
SDOperand ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, VT, LN0->getChain(),
|
|
LN0->getBasePtr(), LN0->getSrcValue(),
|
|
LN0->getSrcValueOffset(),
|
|
N0.getValueType(),
|
|
LN0->isVolatile(),
|
|
LN0->getAlignment());
|
|
CombineTo(N, ExtLoad);
|
|
CombineTo(N0.Val, DAG.getNode(ISD::TRUNCATE, N0.getValueType(), ExtLoad),
|
|
ExtLoad.getValue(1));
|
|
return SDOperand(N, 0); // Return N so it doesn't get rechecked!
|
|
}
|
|
|
|
// fold (zext (zextload x)) -> (zext (truncate (zextload x)))
|
|
// fold (zext ( extload x)) -> (zext (truncate (zextload x)))
|
|
if ((ISD::isZEXTLoad(N0.Val) || ISD::isEXTLoad(N0.Val)) &&
|
|
ISD::isUNINDEXEDLoad(N0.Val) && N0.hasOneUse()) {
|
|
LoadSDNode *LN0 = cast<LoadSDNode>(N0);
|
|
MVT::ValueType EVT = LN0->getLoadedVT();
|
|
SDOperand ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, VT, LN0->getChain(),
|
|
LN0->getBasePtr(), LN0->getSrcValue(),
|
|
LN0->getSrcValueOffset(), EVT,
|
|
LN0->isVolatile(),
|
|
LN0->getAlignment());
|
|
CombineTo(N, ExtLoad);
|
|
CombineTo(N0.Val, DAG.getNode(ISD::TRUNCATE, N0.getValueType(), ExtLoad),
|
|
ExtLoad.getValue(1));
|
|
return SDOperand(N, 0); // Return N so it doesn't get rechecked!
|
|
}
|
|
|
|
// zext(setcc x,y,cc) -> select_cc x, y, 1, 0, cc
|
|
if (N0.getOpcode() == ISD::SETCC) {
|
|
SDOperand SCC =
|
|
SimplifySelectCC(N0.getOperand(0), N0.getOperand(1),
|
|
DAG.getConstant(1, VT), DAG.getConstant(0, VT),
|
|
cast<CondCodeSDNode>(N0.getOperand(2))->get(), true);
|
|
if (SCC.Val) return SCC;
|
|
}
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitANY_EXTEND(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
MVT::ValueType VT = N->getValueType(0);
|
|
|
|
// fold (aext c1) -> c1
|
|
if (isa<ConstantSDNode>(N0))
|
|
return DAG.getNode(ISD::ANY_EXTEND, VT, N0);
|
|
// fold (aext (aext x)) -> (aext x)
|
|
// fold (aext (zext x)) -> (zext x)
|
|
// fold (aext (sext x)) -> (sext x)
|
|
if (N0.getOpcode() == ISD::ANY_EXTEND ||
|
|
N0.getOpcode() == ISD::ZERO_EXTEND ||
|
|
N0.getOpcode() == ISD::SIGN_EXTEND)
|
|
return DAG.getNode(N0.getOpcode(), VT, N0.getOperand(0));
|
|
|
|
// fold (aext (truncate (load x))) -> (aext (smaller load x))
|
|
// fold (aext (truncate (srl (load x), c))) -> (aext (small load (x+c/n)))
|
|
if (N0.getOpcode() == ISD::TRUNCATE) {
|
|
SDOperand NarrowLoad = ReduceLoadWidth(N0.Val);
|
|
if (NarrowLoad.Val) {
|
|
if (NarrowLoad.Val != N0.Val)
|
|
CombineTo(N0.Val, NarrowLoad);
|
|
return DAG.getNode(ISD::ANY_EXTEND, VT, NarrowLoad);
|
|
}
|
|
}
|
|
|
|
// fold (aext (truncate x))
|
|
if (N0.getOpcode() == ISD::TRUNCATE) {
|
|
SDOperand TruncOp = N0.getOperand(0);
|
|
if (TruncOp.getValueType() == VT)
|
|
return TruncOp; // x iff x size == zext size.
|
|
if (TruncOp.getValueType() > VT)
|
|
return DAG.getNode(ISD::TRUNCATE, VT, TruncOp);
|
|
return DAG.getNode(ISD::ANY_EXTEND, VT, TruncOp);
|
|
}
|
|
|
|
// fold (aext (and (trunc x), cst)) -> (and x, cst).
|
|
if (N0.getOpcode() == ISD::AND &&
|
|
N0.getOperand(0).getOpcode() == ISD::TRUNCATE &&
|
|
N0.getOperand(1).getOpcode() == ISD::Constant) {
|
|
SDOperand X = N0.getOperand(0).getOperand(0);
|
|
if (X.getValueType() < VT) {
|
|
X = DAG.getNode(ISD::ANY_EXTEND, VT, X);
|
|
} else if (X.getValueType() > VT) {
|
|
X = DAG.getNode(ISD::TRUNCATE, VT, X);
|
|
}
|
|
uint64_t Mask = cast<ConstantSDNode>(N0.getOperand(1))->getValue();
|
|
return DAG.getNode(ISD::AND, VT, X, DAG.getConstant(Mask, VT));
|
|
}
|
|
|
|
// fold (aext (load x)) -> (aext (truncate (extload x)))
|
|
if (ISD::isNON_EXTLoad(N0.Val) && N0.hasOneUse() &&
|
|
(!AfterLegalize||TLI.isLoadXLegal(ISD::EXTLOAD, N0.getValueType()))) {
|
|
LoadSDNode *LN0 = cast<LoadSDNode>(N0);
|
|
SDOperand ExtLoad = DAG.getExtLoad(ISD::EXTLOAD, VT, LN0->getChain(),
|
|
LN0->getBasePtr(), LN0->getSrcValue(),
|
|
LN0->getSrcValueOffset(),
|
|
N0.getValueType(),
|
|
LN0->isVolatile(),
|
|
LN0->getAlignment());
|
|
CombineTo(N, ExtLoad);
|
|
CombineTo(N0.Val, DAG.getNode(ISD::TRUNCATE, N0.getValueType(), ExtLoad),
|
|
ExtLoad.getValue(1));
|
|
return SDOperand(N, 0); // Return N so it doesn't get rechecked!
|
|
}
|
|
|
|
// fold (aext (zextload x)) -> (aext (truncate (zextload x)))
|
|
// fold (aext (sextload x)) -> (aext (truncate (sextload x)))
|
|
// fold (aext ( extload x)) -> (aext (truncate (extload x)))
|
|
if (N0.getOpcode() == ISD::LOAD &&
|
|
!ISD::isNON_EXTLoad(N0.Val) && ISD::isUNINDEXEDLoad(N0.Val) &&
|
|
N0.hasOneUse()) {
|
|
LoadSDNode *LN0 = cast<LoadSDNode>(N0);
|
|
MVT::ValueType EVT = LN0->getLoadedVT();
|
|
SDOperand ExtLoad = DAG.getExtLoad(LN0->getExtensionType(), VT,
|
|
LN0->getChain(), LN0->getBasePtr(),
|
|
LN0->getSrcValue(),
|
|
LN0->getSrcValueOffset(), EVT,
|
|
LN0->isVolatile(),
|
|
LN0->getAlignment());
|
|
CombineTo(N, ExtLoad);
|
|
CombineTo(N0.Val, DAG.getNode(ISD::TRUNCATE, N0.getValueType(), ExtLoad),
|
|
ExtLoad.getValue(1));
|
|
return SDOperand(N, 0); // Return N so it doesn't get rechecked!
|
|
}
|
|
|
|
// aext(setcc x,y,cc) -> select_cc x, y, 1, 0, cc
|
|
if (N0.getOpcode() == ISD::SETCC) {
|
|
SDOperand SCC =
|
|
SimplifySelectCC(N0.getOperand(0), N0.getOperand(1),
|
|
DAG.getConstant(1, VT), DAG.getConstant(0, VT),
|
|
cast<CondCodeSDNode>(N0.getOperand(2))->get(), true);
|
|
if (SCC.Val)
|
|
return SCC;
|
|
}
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
/// GetDemandedBits - See if the specified operand can be simplified with the
|
|
/// knowledge that only the bits specified by Mask are used. If so, return the
|
|
/// simpler operand, otherwise return a null SDOperand.
|
|
SDOperand DAGCombiner::GetDemandedBits(SDOperand V, uint64_t Mask) {
|
|
switch (V.getOpcode()) {
|
|
default: break;
|
|
case ISD::OR:
|
|
case ISD::XOR:
|
|
// If the LHS or RHS don't contribute bits to the or, drop them.
|
|
if (DAG.MaskedValueIsZero(V.getOperand(0), Mask))
|
|
return V.getOperand(1);
|
|
if (DAG.MaskedValueIsZero(V.getOperand(1), Mask))
|
|
return V.getOperand(0);
|
|
break;
|
|
case ISD::SRL:
|
|
// Only look at single-use SRLs.
|
|
if (!V.Val->hasOneUse())
|
|
break;
|
|
if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(V.getOperand(1))) {
|
|
// See if we can recursively simplify the LHS.
|
|
unsigned Amt = RHSC->getValue();
|
|
Mask = (Mask << Amt) & MVT::getIntVTBitMask(V.getValueType());
|
|
SDOperand SimplifyLHS = GetDemandedBits(V.getOperand(0), Mask);
|
|
if (SimplifyLHS.Val) {
|
|
return DAG.getNode(ISD::SRL, V.getValueType(),
|
|
SimplifyLHS, V.getOperand(1));
|
|
}
|
|
}
|
|
}
|
|
return SDOperand();
|
|
}
|
|
|
|
/// ReduceLoadWidth - If the result of a wider load is shifted to right of N
|
|
/// bits and then truncated to a narrower type and where N is a multiple
|
|
/// of number of bits of the narrower type, transform it to a narrower load
|
|
/// from address + N / num of bits of new type. If the result is to be
|
|
/// extended, also fold the extension to form a extending load.
|
|
SDOperand DAGCombiner::ReduceLoadWidth(SDNode *N) {
|
|
unsigned Opc = N->getOpcode();
|
|
ISD::LoadExtType ExtType = ISD::NON_EXTLOAD;
|
|
SDOperand N0 = N->getOperand(0);
|
|
MVT::ValueType VT = N->getValueType(0);
|
|
MVT::ValueType EVT = N->getValueType(0);
|
|
|
|
// Special case: SIGN_EXTEND_INREG is basically truncating to EVT then
|
|
// extended to VT.
|
|
if (Opc == ISD::SIGN_EXTEND_INREG) {
|
|
ExtType = ISD::SEXTLOAD;
|
|
EVT = cast<VTSDNode>(N->getOperand(1))->getVT();
|
|
if (AfterLegalize && !TLI.isLoadXLegal(ISD::SEXTLOAD, EVT))
|
|
return SDOperand();
|
|
}
|
|
|
|
unsigned EVTBits = MVT::getSizeInBits(EVT);
|
|
unsigned ShAmt = 0;
|
|
bool CombineSRL = false;
|
|
if (N0.getOpcode() == ISD::SRL && N0.hasOneUse()) {
|
|
if (ConstantSDNode *N01 = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
|
|
ShAmt = N01->getValue();
|
|
// Is the shift amount a multiple of size of VT?
|
|
if ((ShAmt & (EVTBits-1)) == 0) {
|
|
N0 = N0.getOperand(0);
|
|
if (MVT::getSizeInBits(N0.getValueType()) <= EVTBits)
|
|
return SDOperand();
|
|
CombineSRL = true;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (ISD::isNON_EXTLoad(N0.Val) && N0.hasOneUse() &&
|
|
// Do not allow folding to i1 here. i1 is implicitly stored in memory in
|
|
// zero extended form: by shrinking the load, we lose track of the fact
|
|
// that it is already zero extended.
|
|
// FIXME: This should be reevaluated.
|
|
VT != MVT::i1) {
|
|
assert(MVT::getSizeInBits(N0.getValueType()) > EVTBits &&
|
|
"Cannot truncate to larger type!");
|
|
LoadSDNode *LN0 = cast<LoadSDNode>(N0);
|
|
MVT::ValueType PtrType = N0.getOperand(1).getValueType();
|
|
// For big endian targets, we need to adjust the offset to the pointer to
|
|
// load the correct bytes.
|
|
if (!TLI.isLittleEndian())
|
|
ShAmt = MVT::getSizeInBits(N0.getValueType()) - ShAmt - EVTBits;
|
|
uint64_t PtrOff = ShAmt / 8;
|
|
SDOperand NewPtr = DAG.getNode(ISD::ADD, PtrType, LN0->getBasePtr(),
|
|
DAG.getConstant(PtrOff, PtrType));
|
|
AddToWorkList(NewPtr.Val);
|
|
SDOperand Load = (ExtType == ISD::NON_EXTLOAD)
|
|
? DAG.getLoad(VT, LN0->getChain(), NewPtr,
|
|
LN0->getSrcValue(), LN0->getSrcValueOffset(),
|
|
LN0->isVolatile(), LN0->getAlignment())
|
|
: DAG.getExtLoad(ExtType, VT, LN0->getChain(), NewPtr,
|
|
LN0->getSrcValue(), LN0->getSrcValueOffset(), EVT,
|
|
LN0->isVolatile(), LN0->getAlignment());
|
|
AddToWorkList(N);
|
|
if (CombineSRL) {
|
|
DAG.ReplaceAllUsesOfValueWith(N0.getValue(1), Load.getValue(1));
|
|
CombineTo(N->getOperand(0).Val, Load);
|
|
} else
|
|
CombineTo(N0.Val, Load, Load.getValue(1));
|
|
if (ShAmt) {
|
|
if (Opc == ISD::SIGN_EXTEND_INREG)
|
|
return DAG.getNode(Opc, VT, Load, N->getOperand(1));
|
|
else
|
|
return DAG.getNode(Opc, VT, Load);
|
|
}
|
|
return SDOperand(N, 0); // Return N so it doesn't get rechecked!
|
|
}
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
|
|
SDOperand DAGCombiner::visitSIGN_EXTEND_INREG(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
SDOperand N1 = N->getOperand(1);
|
|
MVT::ValueType VT = N->getValueType(0);
|
|
MVT::ValueType EVT = cast<VTSDNode>(N1)->getVT();
|
|
unsigned EVTBits = MVT::getSizeInBits(EVT);
|
|
|
|
// fold (sext_in_reg c1) -> c1
|
|
if (isa<ConstantSDNode>(N0) || N0.getOpcode() == ISD::UNDEF)
|
|
return DAG.getNode(ISD::SIGN_EXTEND_INREG, VT, N0, N1);
|
|
|
|
// If the input is already sign extended, just drop the extension.
|
|
if (DAG.ComputeNumSignBits(N0) >= MVT::getSizeInBits(VT)-EVTBits+1)
|
|
return N0;
|
|
|
|
// fold (sext_in_reg (sext_in_reg x, VT2), VT1) -> (sext_in_reg x, minVT) pt2
|
|
if (N0.getOpcode() == ISD::SIGN_EXTEND_INREG &&
|
|
EVT < cast<VTSDNode>(N0.getOperand(1))->getVT()) {
|
|
return DAG.getNode(ISD::SIGN_EXTEND_INREG, VT, N0.getOperand(0), N1);
|
|
}
|
|
|
|
// fold (sext_in_reg x) -> (zext_in_reg x) if the sign bit is known zero.
|
|
if (DAG.MaskedValueIsZero(N0, 1ULL << (EVTBits-1)))
|
|
return DAG.getZeroExtendInReg(N0, EVT);
|
|
|
|
// fold operands of sext_in_reg based on knowledge that the top bits are not
|
|
// demanded.
|
|
if (SimplifyDemandedBits(SDOperand(N, 0)))
|
|
return SDOperand(N, 0);
|
|
|
|
// fold (sext_in_reg (load x)) -> (smaller sextload x)
|
|
// fold (sext_in_reg (srl (load x), c)) -> (smaller sextload (x+c/evtbits))
|
|
SDOperand NarrowLoad = ReduceLoadWidth(N);
|
|
if (NarrowLoad.Val)
|
|
return NarrowLoad;
|
|
|
|
// fold (sext_in_reg (srl X, 24), i8) -> sra X, 24
|
|
// fold (sext_in_reg (srl X, 23), i8) -> sra X, 23 iff possible.
|
|
// We already fold "(sext_in_reg (srl X, 25), i8) -> srl X, 25" above.
|
|
if (N0.getOpcode() == ISD::SRL) {
|
|
if (ConstantSDNode *ShAmt = dyn_cast<ConstantSDNode>(N0.getOperand(1)))
|
|
if (ShAmt->getValue()+EVTBits <= MVT::getSizeInBits(VT)) {
|
|
// We can turn this into an SRA iff the input to the SRL is already sign
|
|
// extended enough.
|
|
unsigned InSignBits = DAG.ComputeNumSignBits(N0.getOperand(0));
|
|
if (MVT::getSizeInBits(VT)-(ShAmt->getValue()+EVTBits) < InSignBits)
|
|
return DAG.getNode(ISD::SRA, VT, N0.getOperand(0), N0.getOperand(1));
|
|
}
|
|
}
|
|
|
|
// fold (sext_inreg (extload x)) -> (sextload x)
|
|
if (ISD::isEXTLoad(N0.Val) &&
|
|
ISD::isUNINDEXEDLoad(N0.Val) &&
|
|
EVT == cast<LoadSDNode>(N0)->getLoadedVT() &&
|
|
(!AfterLegalize || TLI.isLoadXLegal(ISD::SEXTLOAD, EVT))) {
|
|
LoadSDNode *LN0 = cast<LoadSDNode>(N0);
|
|
SDOperand ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, VT, LN0->getChain(),
|
|
LN0->getBasePtr(), LN0->getSrcValue(),
|
|
LN0->getSrcValueOffset(), EVT,
|
|
LN0->isVolatile(),
|
|
LN0->getAlignment());
|
|
CombineTo(N, ExtLoad);
|
|
CombineTo(N0.Val, ExtLoad, ExtLoad.getValue(1));
|
|
return SDOperand(N, 0); // Return N so it doesn't get rechecked!
|
|
}
|
|
// fold (sext_inreg (zextload x)) -> (sextload x) iff load has one use
|
|
if (ISD::isZEXTLoad(N0.Val) && ISD::isUNINDEXEDLoad(N0.Val) &&
|
|
N0.hasOneUse() &&
|
|
EVT == cast<LoadSDNode>(N0)->getLoadedVT() &&
|
|
(!AfterLegalize || TLI.isLoadXLegal(ISD::SEXTLOAD, EVT))) {
|
|
LoadSDNode *LN0 = cast<LoadSDNode>(N0);
|
|
SDOperand ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, VT, LN0->getChain(),
|
|
LN0->getBasePtr(), LN0->getSrcValue(),
|
|
LN0->getSrcValueOffset(), EVT,
|
|
LN0->isVolatile(),
|
|
LN0->getAlignment());
|
|
CombineTo(N, ExtLoad);
|
|
CombineTo(N0.Val, ExtLoad, ExtLoad.getValue(1));
|
|
return SDOperand(N, 0); // Return N so it doesn't get rechecked!
|
|
}
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitTRUNCATE(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
MVT::ValueType VT = N->getValueType(0);
|
|
|
|
// noop truncate
|
|
if (N0.getValueType() == N->getValueType(0))
|
|
return N0;
|
|
// fold (truncate c1) -> c1
|
|
if (isa<ConstantSDNode>(N0))
|
|
return DAG.getNode(ISD::TRUNCATE, VT, N0);
|
|
// fold (truncate (truncate x)) -> (truncate x)
|
|
if (N0.getOpcode() == ISD::TRUNCATE)
|
|
return DAG.getNode(ISD::TRUNCATE, VT, N0.getOperand(0));
|
|
// fold (truncate (ext x)) -> (ext x) or (truncate x) or x
|
|
if (N0.getOpcode() == ISD::ZERO_EXTEND || N0.getOpcode() == ISD::SIGN_EXTEND||
|
|
N0.getOpcode() == ISD::ANY_EXTEND) {
|
|
if (N0.getOperand(0).getValueType() < VT)
|
|
// if the source is smaller than the dest, we still need an extend
|
|
return DAG.getNode(N0.getOpcode(), VT, N0.getOperand(0));
|
|
else if (N0.getOperand(0).getValueType() > VT)
|
|
// if the source is larger than the dest, than we just need the truncate
|
|
return DAG.getNode(ISD::TRUNCATE, VT, N0.getOperand(0));
|
|
else
|
|
// if the source and dest are the same type, we can drop both the extend
|
|
// and the truncate
|
|
return N0.getOperand(0);
|
|
}
|
|
|
|
// See if we can simplify the input to this truncate through knowledge that
|
|
// only the low bits are being used. For example "trunc (or (shl x, 8), y)"
|
|
// -> trunc y
|
|
SDOperand Shorter = GetDemandedBits(N0, MVT::getIntVTBitMask(VT));
|
|
if (Shorter.Val)
|
|
return DAG.getNode(ISD::TRUNCATE, VT, Shorter);
|
|
|
|
// fold (truncate (load x)) -> (smaller load x)
|
|
// fold (truncate (srl (load x), c)) -> (smaller load (x+c/evtbits))
|
|
return ReduceLoadWidth(N);
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitBIT_CONVERT(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
MVT::ValueType VT = N->getValueType(0);
|
|
|
|
// If the input is a BUILD_VECTOR with all constant elements, fold this now.
|
|
// Only do this before legalize, since afterward the target may be depending
|
|
// on the bitconvert.
|
|
// First check to see if this is all constant.
|
|
if (!AfterLegalize &&
|
|
N0.getOpcode() == ISD::BUILD_VECTOR && N0.Val->hasOneUse() &&
|
|
MVT::isVector(VT)) {
|
|
bool isSimple = true;
|
|
for (unsigned i = 0, e = N0.getNumOperands(); i != e; ++i)
|
|
if (N0.getOperand(i).getOpcode() != ISD::UNDEF &&
|
|
N0.getOperand(i).getOpcode() != ISD::Constant &&
|
|
N0.getOperand(i).getOpcode() != ISD::ConstantFP) {
|
|
isSimple = false;
|
|
break;
|
|
}
|
|
|
|
MVT::ValueType DestEltVT = MVT::getVectorElementType(N->getValueType(0));
|
|
assert(!MVT::isVector(DestEltVT) &&
|
|
"Element type of vector ValueType must not be vector!");
|
|
if (isSimple) {
|
|
return ConstantFoldBIT_CONVERTofBUILD_VECTOR(N0.Val, DestEltVT);
|
|
}
|
|
}
|
|
|
|
// If the input is a constant, let getNode() fold it.
|
|
if (isa<ConstantSDNode>(N0) || isa<ConstantFPSDNode>(N0)) {
|
|
SDOperand Res = DAG.getNode(ISD::BIT_CONVERT, VT, N0);
|
|
if (Res.Val != N) return Res;
|
|
}
|
|
|
|
if (N0.getOpcode() == ISD::BIT_CONVERT) // conv(conv(x,t1),t2) -> conv(x,t2)
|
|
return DAG.getNode(ISD::BIT_CONVERT, VT, N0.getOperand(0));
|
|
|
|
// fold (conv (load x)) -> (load (conv*)x)
|
|
// If the resultant load doesn't need a higher alignment than the original!
|
|
if (ISD::isNormalLoad(N0.Val) && N0.hasOneUse() &&
|
|
TLI.isOperationLegal(ISD::LOAD, VT)) {
|
|
LoadSDNode *LN0 = cast<LoadSDNode>(N0);
|
|
unsigned Align = TLI.getTargetMachine().getTargetData()->
|
|
getABITypeAlignment(MVT::getTypeForValueType(VT));
|
|
unsigned OrigAlign = LN0->getAlignment();
|
|
if (Align <= OrigAlign) {
|
|
SDOperand Load = DAG.getLoad(VT, LN0->getChain(), LN0->getBasePtr(),
|
|
LN0->getSrcValue(), LN0->getSrcValueOffset(),
|
|
LN0->isVolatile(), Align);
|
|
AddToWorkList(N);
|
|
CombineTo(N0.Val, DAG.getNode(ISD::BIT_CONVERT, N0.getValueType(), Load),
|
|
Load.getValue(1));
|
|
return Load;
|
|
}
|
|
}
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
/// ConstantFoldBIT_CONVERTofBUILD_VECTOR - We know that BV is a build_vector
|
|
/// node with Constant, ConstantFP or Undef operands. DstEltVT indicates the
|
|
/// destination element value type.
|
|
SDOperand DAGCombiner::
|
|
ConstantFoldBIT_CONVERTofBUILD_VECTOR(SDNode *BV, MVT::ValueType DstEltVT) {
|
|
MVT::ValueType SrcEltVT = BV->getOperand(0).getValueType();
|
|
|
|
// If this is already the right type, we're done.
|
|
if (SrcEltVT == DstEltVT) return SDOperand(BV, 0);
|
|
|
|
unsigned SrcBitSize = MVT::getSizeInBits(SrcEltVT);
|
|
unsigned DstBitSize = MVT::getSizeInBits(DstEltVT);
|
|
|
|
// If this is a conversion of N elements of one type to N elements of another
|
|
// type, convert each element. This handles FP<->INT cases.
|
|
if (SrcBitSize == DstBitSize) {
|
|
SmallVector<SDOperand, 8> Ops;
|
|
for (unsigned i = 0, e = BV->getNumOperands(); i != e; ++i) {
|
|
Ops.push_back(DAG.getNode(ISD::BIT_CONVERT, DstEltVT, BV->getOperand(i)));
|
|
AddToWorkList(Ops.back().Val);
|
|
}
|
|
MVT::ValueType VT =
|
|
MVT::getVectorType(DstEltVT,
|
|
MVT::getVectorNumElements(BV->getValueType(0)));
|
|
return DAG.getNode(ISD::BUILD_VECTOR, VT, &Ops[0], Ops.size());
|
|
}
|
|
|
|
// Otherwise, we're growing or shrinking the elements. To avoid having to
|
|
// handle annoying details of growing/shrinking FP values, we convert them to
|
|
// int first.
|
|
if (MVT::isFloatingPoint(SrcEltVT)) {
|
|
// Convert the input float vector to a int vector where the elements are the
|
|
// same sizes.
|
|
assert((SrcEltVT == MVT::f32 || SrcEltVT == MVT::f64) && "Unknown FP VT!");
|
|
MVT::ValueType IntVT = SrcEltVT == MVT::f32 ? MVT::i32 : MVT::i64;
|
|
BV = ConstantFoldBIT_CONVERTofBUILD_VECTOR(BV, IntVT).Val;
|
|
SrcEltVT = IntVT;
|
|
}
|
|
|
|
// Now we know the input is an integer vector. If the output is a FP type,
|
|
// convert to integer first, then to FP of the right size.
|
|
if (MVT::isFloatingPoint(DstEltVT)) {
|
|
assert((DstEltVT == MVT::f32 || DstEltVT == MVT::f64) && "Unknown FP VT!");
|
|
MVT::ValueType TmpVT = DstEltVT == MVT::f32 ? MVT::i32 : MVT::i64;
|
|
SDNode *Tmp = ConstantFoldBIT_CONVERTofBUILD_VECTOR(BV, TmpVT).Val;
|
|
|
|
// Next, convert to FP elements of the same size.
|
|
return ConstantFoldBIT_CONVERTofBUILD_VECTOR(Tmp, DstEltVT);
|
|
}
|
|
|
|
// Okay, we know the src/dst types are both integers of differing types.
|
|
// Handling growing first.
|
|
assert(MVT::isInteger(SrcEltVT) && MVT::isInteger(DstEltVT));
|
|
if (SrcBitSize < DstBitSize) {
|
|
unsigned NumInputsPerOutput = DstBitSize/SrcBitSize;
|
|
|
|
SmallVector<SDOperand, 8> Ops;
|
|
for (unsigned i = 0, e = BV->getNumOperands(); i != e;
|
|
i += NumInputsPerOutput) {
|
|
bool isLE = TLI.isLittleEndian();
|
|
uint64_t NewBits = 0;
|
|
bool EltIsUndef = true;
|
|
for (unsigned j = 0; j != NumInputsPerOutput; ++j) {
|
|
// Shift the previously computed bits over.
|
|
NewBits <<= SrcBitSize;
|
|
SDOperand Op = BV->getOperand(i+ (isLE ? (NumInputsPerOutput-j-1) : j));
|
|
if (Op.getOpcode() == ISD::UNDEF) continue;
|
|
EltIsUndef = false;
|
|
|
|
NewBits |= cast<ConstantSDNode>(Op)->getValue();
|
|
}
|
|
|
|
if (EltIsUndef)
|
|
Ops.push_back(DAG.getNode(ISD::UNDEF, DstEltVT));
|
|
else
|
|
Ops.push_back(DAG.getConstant(NewBits, DstEltVT));
|
|
}
|
|
|
|
MVT::ValueType VT = MVT::getVectorType(DstEltVT,
|
|
Ops.size());
|
|
return DAG.getNode(ISD::BUILD_VECTOR, VT, &Ops[0], Ops.size());
|
|
}
|
|
|
|
// Finally, this must be the case where we are shrinking elements: each input
|
|
// turns into multiple outputs.
|
|
unsigned NumOutputsPerInput = SrcBitSize/DstBitSize;
|
|
SmallVector<SDOperand, 8> Ops;
|
|
for (unsigned i = 0, e = BV->getNumOperands(); i != e; ++i) {
|
|
if (BV->getOperand(i).getOpcode() == ISD::UNDEF) {
|
|
for (unsigned j = 0; j != NumOutputsPerInput; ++j)
|
|
Ops.push_back(DAG.getNode(ISD::UNDEF, DstEltVT));
|
|
continue;
|
|
}
|
|
uint64_t OpVal = cast<ConstantSDNode>(BV->getOperand(i))->getValue();
|
|
|
|
for (unsigned j = 0; j != NumOutputsPerInput; ++j) {
|
|
unsigned ThisVal = OpVal & ((1ULL << DstBitSize)-1);
|
|
OpVal >>= DstBitSize;
|
|
Ops.push_back(DAG.getConstant(ThisVal, DstEltVT));
|
|
}
|
|
|
|
// For big endian targets, swap the order of the pieces of each element.
|
|
if (!TLI.isLittleEndian())
|
|
std::reverse(Ops.end()-NumOutputsPerInput, Ops.end());
|
|
}
|
|
MVT::ValueType VT = MVT::getVectorType(DstEltVT, Ops.size());
|
|
return DAG.getNode(ISD::BUILD_VECTOR, VT, &Ops[0], Ops.size());
|
|
}
|
|
|
|
|
|
|
|
SDOperand DAGCombiner::visitFADD(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
SDOperand N1 = N->getOperand(1);
|
|
ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
|
|
ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
|
|
MVT::ValueType VT = N->getValueType(0);
|
|
|
|
// fold vector ops
|
|
if (MVT::isVector(VT)) {
|
|
SDOperand FoldedVOp = SimplifyVBinOp(N);
|
|
if (FoldedVOp.Val) return FoldedVOp;
|
|
}
|
|
|
|
// fold (fadd c1, c2) -> c1+c2
|
|
if (N0CFP && N1CFP && VT != MVT::ppcf128)
|
|
return DAG.getNode(ISD::FADD, VT, N0, N1);
|
|
// canonicalize constant to RHS
|
|
if (N0CFP && !N1CFP)
|
|
return DAG.getNode(ISD::FADD, VT, N1, N0);
|
|
// fold (A + (-B)) -> A-B
|
|
if (isNegatibleForFree(N1) == 2)
|
|
return DAG.getNode(ISD::FSUB, VT, N0, GetNegatedExpression(N1, DAG));
|
|
// fold ((-A) + B) -> B-A
|
|
if (isNegatibleForFree(N0) == 2)
|
|
return DAG.getNode(ISD::FSUB, VT, N1, GetNegatedExpression(N0, DAG));
|
|
|
|
// If allowed, fold (fadd (fadd x, c1), c2) -> (fadd x, (fadd c1, c2))
|
|
if (UnsafeFPMath && N1CFP && N0.getOpcode() == ISD::FADD &&
|
|
N0.Val->hasOneUse() && isa<ConstantFPSDNode>(N0.getOperand(1)))
|
|
return DAG.getNode(ISD::FADD, VT, N0.getOperand(0),
|
|
DAG.getNode(ISD::FADD, VT, N0.getOperand(1), N1));
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitFSUB(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
SDOperand N1 = N->getOperand(1);
|
|
ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
|
|
ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
|
|
MVT::ValueType VT = N->getValueType(0);
|
|
|
|
// fold vector ops
|
|
if (MVT::isVector(VT)) {
|
|
SDOperand FoldedVOp = SimplifyVBinOp(N);
|
|
if (FoldedVOp.Val) return FoldedVOp;
|
|
}
|
|
|
|
// fold (fsub c1, c2) -> c1-c2
|
|
if (N0CFP && N1CFP && VT != MVT::ppcf128)
|
|
return DAG.getNode(ISD::FSUB, VT, N0, N1);
|
|
// fold (0-B) -> -B
|
|
if (UnsafeFPMath && N0CFP && N0CFP->getValueAPF().isZero()) {
|
|
if (isNegatibleForFree(N1))
|
|
return GetNegatedExpression(N1, DAG);
|
|
return DAG.getNode(ISD::FNEG, VT, N1);
|
|
}
|
|
// fold (A-(-B)) -> A+B
|
|
if (isNegatibleForFree(N1))
|
|
return DAG.getNode(ISD::FADD, VT, N0, GetNegatedExpression(N1, DAG));
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitFMUL(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
SDOperand N1 = N->getOperand(1);
|
|
ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
|
|
ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
|
|
MVT::ValueType VT = N->getValueType(0);
|
|
|
|
// fold vector ops
|
|
if (MVT::isVector(VT)) {
|
|
SDOperand FoldedVOp = SimplifyVBinOp(N);
|
|
if (FoldedVOp.Val) return FoldedVOp;
|
|
}
|
|
|
|
// fold (fmul c1, c2) -> c1*c2
|
|
if (N0CFP && N1CFP && VT != MVT::ppcf128)
|
|
return DAG.getNode(ISD::FMUL, VT, N0, N1);
|
|
// canonicalize constant to RHS
|
|
if (N0CFP && !N1CFP)
|
|
return DAG.getNode(ISD::FMUL, VT, N1, N0);
|
|
// fold (fmul X, 2.0) -> (fadd X, X)
|
|
if (N1CFP && N1CFP->isExactlyValue(+2.0))
|
|
return DAG.getNode(ISD::FADD, VT, N0, N0);
|
|
// fold (fmul X, -1.0) -> (fneg X)
|
|
if (N1CFP && N1CFP->isExactlyValue(-1.0))
|
|
return DAG.getNode(ISD::FNEG, VT, N0);
|
|
|
|
// -X * -Y -> X*Y
|
|
if (char LHSNeg = isNegatibleForFree(N0)) {
|
|
if (char RHSNeg = isNegatibleForFree(N1)) {
|
|
// Both can be negated for free, check to see if at least one is cheaper
|
|
// negated.
|
|
if (LHSNeg == 2 || RHSNeg == 2)
|
|
return DAG.getNode(ISD::FMUL, VT, GetNegatedExpression(N0, DAG),
|
|
GetNegatedExpression(N1, DAG));
|
|
}
|
|
}
|
|
|
|
// If allowed, fold (fmul (fmul x, c1), c2) -> (fmul x, (fmul c1, c2))
|
|
if (UnsafeFPMath && N1CFP && N0.getOpcode() == ISD::FMUL &&
|
|
N0.Val->hasOneUse() && isa<ConstantFPSDNode>(N0.getOperand(1)))
|
|
return DAG.getNode(ISD::FMUL, VT, N0.getOperand(0),
|
|
DAG.getNode(ISD::FMUL, VT, N0.getOperand(1), N1));
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitFDIV(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
SDOperand N1 = N->getOperand(1);
|
|
ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
|
|
ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
|
|
MVT::ValueType VT = N->getValueType(0);
|
|
|
|
// fold vector ops
|
|
if (MVT::isVector(VT)) {
|
|
SDOperand FoldedVOp = SimplifyVBinOp(N);
|
|
if (FoldedVOp.Val) return FoldedVOp;
|
|
}
|
|
|
|
// fold (fdiv c1, c2) -> c1/c2
|
|
if (N0CFP && N1CFP && VT != MVT::ppcf128)
|
|
return DAG.getNode(ISD::FDIV, VT, N0, N1);
|
|
|
|
|
|
// -X / -Y -> X*Y
|
|
if (char LHSNeg = isNegatibleForFree(N0)) {
|
|
if (char RHSNeg = isNegatibleForFree(N1)) {
|
|
// Both can be negated for free, check to see if at least one is cheaper
|
|
// negated.
|
|
if (LHSNeg == 2 || RHSNeg == 2)
|
|
return DAG.getNode(ISD::FDIV, VT, GetNegatedExpression(N0, DAG),
|
|
GetNegatedExpression(N1, DAG));
|
|
}
|
|
}
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitFREM(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
SDOperand N1 = N->getOperand(1);
|
|
ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
|
|
ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
|
|
MVT::ValueType VT = N->getValueType(0);
|
|
|
|
// fold (frem c1, c2) -> fmod(c1,c2)
|
|
if (N0CFP && N1CFP && VT != MVT::ppcf128)
|
|
return DAG.getNode(ISD::FREM, VT, N0, N1);
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitFCOPYSIGN(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
SDOperand N1 = N->getOperand(1);
|
|
ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
|
|
ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
|
|
MVT::ValueType VT = N->getValueType(0);
|
|
|
|
if (N0CFP && N1CFP && VT != MVT::ppcf128) // Constant fold
|
|
return DAG.getNode(ISD::FCOPYSIGN, VT, N0, N1);
|
|
|
|
if (N1CFP) {
|
|
const APFloat& V = N1CFP->getValueAPF();
|
|
// copysign(x, c1) -> fabs(x) iff ispos(c1)
|
|
// copysign(x, c1) -> fneg(fabs(x)) iff isneg(c1)
|
|
if (!V.isNegative())
|
|
return DAG.getNode(ISD::FABS, VT, N0);
|
|
else
|
|
return DAG.getNode(ISD::FNEG, VT, DAG.getNode(ISD::FABS, VT, N0));
|
|
}
|
|
|
|
// copysign(fabs(x), y) -> copysign(x, y)
|
|
// copysign(fneg(x), y) -> copysign(x, y)
|
|
// copysign(copysign(x,z), y) -> copysign(x, y)
|
|
if (N0.getOpcode() == ISD::FABS || N0.getOpcode() == ISD::FNEG ||
|
|
N0.getOpcode() == ISD::FCOPYSIGN)
|
|
return DAG.getNode(ISD::FCOPYSIGN, VT, N0.getOperand(0), N1);
|
|
|
|
// copysign(x, abs(y)) -> abs(x)
|
|
if (N1.getOpcode() == ISD::FABS)
|
|
return DAG.getNode(ISD::FABS, VT, N0);
|
|
|
|
// copysign(x, copysign(y,z)) -> copysign(x, z)
|
|
if (N1.getOpcode() == ISD::FCOPYSIGN)
|
|
return DAG.getNode(ISD::FCOPYSIGN, VT, N0, N1.getOperand(1));
|
|
|
|
// copysign(x, fp_extend(y)) -> copysign(x, y)
|
|
// copysign(x, fp_round(y)) -> copysign(x, y)
|
|
if (N1.getOpcode() == ISD::FP_EXTEND || N1.getOpcode() == ISD::FP_ROUND)
|
|
return DAG.getNode(ISD::FCOPYSIGN, VT, N0, N1.getOperand(0));
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
|
|
|
|
SDOperand DAGCombiner::visitSINT_TO_FP(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
|
|
MVT::ValueType VT = N->getValueType(0);
|
|
|
|
// fold (sint_to_fp c1) -> c1fp
|
|
if (N0C && N0.getValueType() != MVT::ppcf128)
|
|
return DAG.getNode(ISD::SINT_TO_FP, VT, N0);
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitUINT_TO_FP(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
|
|
MVT::ValueType VT = N->getValueType(0);
|
|
|
|
// fold (uint_to_fp c1) -> c1fp
|
|
if (N0C && N0.getValueType() != MVT::ppcf128)
|
|
return DAG.getNode(ISD::UINT_TO_FP, VT, N0);
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitFP_TO_SINT(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
|
|
MVT::ValueType VT = N->getValueType(0);
|
|
|
|
// fold (fp_to_sint c1fp) -> c1
|
|
if (N0CFP)
|
|
return DAG.getNode(ISD::FP_TO_SINT, VT, N0);
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitFP_TO_UINT(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
|
|
MVT::ValueType VT = N->getValueType(0);
|
|
|
|
// fold (fp_to_uint c1fp) -> c1
|
|
if (N0CFP && VT != MVT::ppcf128)
|
|
return DAG.getNode(ISD::FP_TO_UINT, VT, N0);
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitFP_ROUND(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
|
|
MVT::ValueType VT = N->getValueType(0);
|
|
|
|
// fold (fp_round c1fp) -> c1fp
|
|
if (N0CFP && N0.getValueType() != MVT::ppcf128)
|
|
return DAG.getNode(ISD::FP_ROUND, VT, N0);
|
|
|
|
// fold (fp_round (fp_extend x)) -> x
|
|
if (N0.getOpcode() == ISD::FP_EXTEND && VT == N0.getOperand(0).getValueType())
|
|
return N0.getOperand(0);
|
|
|
|
// fold (fp_round (copysign X, Y)) -> (copysign (fp_round X), Y)
|
|
if (N0.getOpcode() == ISD::FCOPYSIGN && N0.Val->hasOneUse()) {
|
|
SDOperand Tmp = DAG.getNode(ISD::FP_ROUND, VT, N0.getOperand(0));
|
|
AddToWorkList(Tmp.Val);
|
|
return DAG.getNode(ISD::FCOPYSIGN, VT, Tmp, N0.getOperand(1));
|
|
}
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitFP_ROUND_INREG(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
MVT::ValueType VT = N->getValueType(0);
|
|
MVT::ValueType EVT = cast<VTSDNode>(N->getOperand(1))->getVT();
|
|
ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
|
|
|
|
// fold (fp_round_inreg c1fp) -> c1fp
|
|
if (N0CFP) {
|
|
SDOperand Round = DAG.getConstantFP(N0CFP->getValueAPF(), EVT);
|
|
return DAG.getNode(ISD::FP_EXTEND, VT, Round);
|
|
}
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitFP_EXTEND(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
|
|
MVT::ValueType VT = N->getValueType(0);
|
|
|
|
// fold (fp_extend c1fp) -> c1fp
|
|
if (N0CFP && VT != MVT::ppcf128)
|
|
return DAG.getNode(ISD::FP_EXTEND, VT, N0);
|
|
|
|
// fold (fpext (load x)) -> (fpext (fpround (extload x)))
|
|
if (ISD::isNON_EXTLoad(N0.Val) && N0.hasOneUse() && VT != MVT::ppcf128 &&
|
|
(!AfterLegalize||TLI.isLoadXLegal(ISD::EXTLOAD, N0.getValueType()))) {
|
|
LoadSDNode *LN0 = cast<LoadSDNode>(N0);
|
|
SDOperand ExtLoad = DAG.getExtLoad(ISD::EXTLOAD, VT, LN0->getChain(),
|
|
LN0->getBasePtr(), LN0->getSrcValue(),
|
|
LN0->getSrcValueOffset(),
|
|
N0.getValueType(),
|
|
LN0->isVolatile(),
|
|
LN0->getAlignment());
|
|
CombineTo(N, ExtLoad);
|
|
CombineTo(N0.Val, DAG.getNode(ISD::FP_ROUND, N0.getValueType(), ExtLoad),
|
|
ExtLoad.getValue(1));
|
|
return SDOperand(N, 0); // Return N so it doesn't get rechecked!
|
|
}
|
|
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitFNEG(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
|
|
if (isNegatibleForFree(N0))
|
|
return GetNegatedExpression(N0, DAG);
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitFABS(SDNode *N) {
|
|
SDOperand N0 = N->getOperand(0);
|
|
ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
|
|
MVT::ValueType VT = N->getValueType(0);
|
|
|
|
// fold (fabs c1) -> fabs(c1)
|
|
if (N0CFP && VT != MVT::ppcf128)
|
|
return DAG.getNode(ISD::FABS, VT, N0);
|
|
// fold (fabs (fabs x)) -> (fabs x)
|
|
if (N0.getOpcode() == ISD::FABS)
|
|
return N->getOperand(0);
|
|
// fold (fabs (fneg x)) -> (fabs x)
|
|
// fold (fabs (fcopysign x, y)) -> (fabs x)
|
|
if (N0.getOpcode() == ISD::FNEG || N0.getOpcode() == ISD::FCOPYSIGN)
|
|
return DAG.getNode(ISD::FABS, VT, N0.getOperand(0));
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitBRCOND(SDNode *N) {
|
|
SDOperand Chain = N->getOperand(0);
|
|
SDOperand N1 = N->getOperand(1);
|
|
SDOperand N2 = N->getOperand(2);
|
|
ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
|
|
|
|
// never taken branch, fold to chain
|
|
if (N1C && N1C->isNullValue())
|
|
return Chain;
|
|
// unconditional branch
|
|
if (N1C && N1C->getValue() == 1)
|
|
return DAG.getNode(ISD::BR, MVT::Other, Chain, N2);
|
|
// fold a brcond with a setcc condition into a BR_CC node if BR_CC is legal
|
|
// on the target.
|
|
if (N1.getOpcode() == ISD::SETCC &&
|
|
TLI.isOperationLegal(ISD::BR_CC, MVT::Other)) {
|
|
return DAG.getNode(ISD::BR_CC, MVT::Other, Chain, N1.getOperand(2),
|
|
N1.getOperand(0), N1.getOperand(1), N2);
|
|
}
|
|
return SDOperand();
|
|
}
|
|
|
|
// Operand List for BR_CC: Chain, CondCC, CondLHS, CondRHS, DestBB.
|
|
//
|
|
SDOperand DAGCombiner::visitBR_CC(SDNode *N) {
|
|
CondCodeSDNode *CC = cast<CondCodeSDNode>(N->getOperand(1));
|
|
SDOperand CondLHS = N->getOperand(2), CondRHS = N->getOperand(3);
|
|
|
|
// Use SimplifySetCC to simplify SETCC's.
|
|
SDOperand Simp = SimplifySetCC(MVT::i1, CondLHS, CondRHS, CC->get(), false);
|
|
if (Simp.Val) AddToWorkList(Simp.Val);
|
|
|
|
ConstantSDNode *SCCC = dyn_cast_or_null<ConstantSDNode>(Simp.Val);
|
|
|
|
// fold br_cc true, dest -> br dest (unconditional branch)
|
|
if (SCCC && SCCC->getValue())
|
|
return DAG.getNode(ISD::BR, MVT::Other, N->getOperand(0),
|
|
N->getOperand(4));
|
|
// fold br_cc false, dest -> unconditional fall through
|
|
if (SCCC && SCCC->isNullValue())
|
|
return N->getOperand(0);
|
|
|
|
// fold to a simpler setcc
|
|
if (Simp.Val && Simp.getOpcode() == ISD::SETCC)
|
|
return DAG.getNode(ISD::BR_CC, MVT::Other, N->getOperand(0),
|
|
Simp.getOperand(2), Simp.getOperand(0),
|
|
Simp.getOperand(1), N->getOperand(4));
|
|
return SDOperand();
|
|
}
|
|
|
|
|
|
/// CombineToPreIndexedLoadStore - Try turning a load / store and a
|
|
/// pre-indexed load / store when the base pointer is a add or subtract
|
|
/// and it has other uses besides the load / store. After the
|
|
/// transformation, the new indexed load / store has effectively folded
|
|
/// the add / subtract in and all of its other uses are redirected to the
|
|
/// new load / store.
|
|
bool DAGCombiner::CombineToPreIndexedLoadStore(SDNode *N) {
|
|
if (!AfterLegalize)
|
|
return false;
|
|
|
|
bool isLoad = true;
|
|
SDOperand Ptr;
|
|
MVT::ValueType VT;
|
|
if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
|
|
if (LD->getAddressingMode() != ISD::UNINDEXED)
|
|
return false;
|
|
VT = LD->getLoadedVT();
|
|
if (!TLI.isIndexedLoadLegal(ISD::PRE_INC, VT) &&
|
|
!TLI.isIndexedLoadLegal(ISD::PRE_DEC, VT))
|
|
return false;
|
|
Ptr = LD->getBasePtr();
|
|
} else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
|
|
if (ST->getAddressingMode() != ISD::UNINDEXED)
|
|
return false;
|
|
VT = ST->getStoredVT();
|
|
if (!TLI.isIndexedStoreLegal(ISD::PRE_INC, VT) &&
|
|
!TLI.isIndexedStoreLegal(ISD::PRE_DEC, VT))
|
|
return false;
|
|
Ptr = ST->getBasePtr();
|
|
isLoad = false;
|
|
} else
|
|
return false;
|
|
|
|
// If the pointer is not an add/sub, or if it doesn't have multiple uses, bail
|
|
// out. There is no reason to make this a preinc/predec.
|
|
if ((Ptr.getOpcode() != ISD::ADD && Ptr.getOpcode() != ISD::SUB) ||
|
|
Ptr.Val->hasOneUse())
|
|
return false;
|
|
|
|
// Ask the target to do addressing mode selection.
|
|
SDOperand BasePtr;
|
|
SDOperand Offset;
|
|
ISD::MemIndexedMode AM = ISD::UNINDEXED;
|
|
if (!TLI.getPreIndexedAddressParts(N, BasePtr, Offset, AM, DAG))
|
|
return false;
|
|
// Don't create a indexed load / store with zero offset.
|
|
if (isa<ConstantSDNode>(Offset) &&
|
|
cast<ConstantSDNode>(Offset)->getValue() == 0)
|
|
return false;
|
|
|
|
// Try turning it into a pre-indexed load / store except when:
|
|
// 1) The new base ptr is a frame index.
|
|
// 2) If N is a store and the new base ptr is either the same as or is a
|
|
// predecessor of the value being stored.
|
|
// 3) Another use of old base ptr is a predecessor of N. If ptr is folded
|
|
// that would create a cycle.
|
|
// 4) All uses are load / store ops that use it as old base ptr.
|
|
|
|
// Check #1. Preinc'ing a frame index would require copying the stack pointer
|
|
// (plus the implicit offset) to a register to preinc anyway.
|
|
if (isa<FrameIndexSDNode>(BasePtr))
|
|
return false;
|
|
|
|
// Check #2.
|
|
if (!isLoad) {
|
|
SDOperand Val = cast<StoreSDNode>(N)->getValue();
|
|
if (Val == BasePtr || BasePtr.Val->isPredecessor(Val.Val))
|
|
return false;
|
|
}
|
|
|
|
// Now check for #3 and #4.
|
|
bool RealUse = false;
|
|
for (SDNode::use_iterator I = Ptr.Val->use_begin(),
|
|
E = Ptr.Val->use_end(); I != E; ++I) {
|
|
SDNode *Use = *I;
|
|
if (Use == N)
|
|
continue;
|
|
if (Use->isPredecessor(N))
|
|
return false;
|
|
|
|
if (!((Use->getOpcode() == ISD::LOAD &&
|
|
cast<LoadSDNode>(Use)->getBasePtr() == Ptr) ||
|
|
(Use->getOpcode() == ISD::STORE) &&
|
|
cast<StoreSDNode>(Use)->getBasePtr() == Ptr))
|
|
RealUse = true;
|
|
}
|
|
if (!RealUse)
|
|
return false;
|
|
|
|
SDOperand Result;
|
|
if (isLoad)
|
|
Result = DAG.getIndexedLoad(SDOperand(N,0), BasePtr, Offset, AM);
|
|
else
|
|
Result = DAG.getIndexedStore(SDOperand(N,0), BasePtr, Offset, AM);
|
|
++PreIndexedNodes;
|
|
++NodesCombined;
|
|
DOUT << "\nReplacing.4 "; DEBUG(N->dump(&DAG));
|
|
DOUT << "\nWith: "; DEBUG(Result.Val->dump(&DAG));
|
|
DOUT << '\n';
|
|
std::vector<SDNode*> NowDead;
|
|
if (isLoad) {
|
|
DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 0), Result.getValue(0),
|
|
&NowDead);
|
|
DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 1), Result.getValue(2),
|
|
&NowDead);
|
|
} else {
|
|
DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 0), Result.getValue(1),
|
|
&NowDead);
|
|
}
|
|
|
|
// Nodes can end up on the worklist more than once. Make sure we do
|
|
// not process a node that has been replaced.
|
|
for (unsigned i = 0, e = NowDead.size(); i != e; ++i)
|
|
removeFromWorkList(NowDead[i]);
|
|
// Finally, since the node is now dead, remove it from the graph.
|
|
DAG.DeleteNode(N);
|
|
|
|
// Replace the uses of Ptr with uses of the updated base value.
|
|
DAG.ReplaceAllUsesOfValueWith(Ptr, Result.getValue(isLoad ? 1 : 0),
|
|
&NowDead);
|
|
removeFromWorkList(Ptr.Val);
|
|
for (unsigned i = 0, e = NowDead.size(); i != e; ++i)
|
|
removeFromWorkList(NowDead[i]);
|
|
DAG.DeleteNode(Ptr.Val);
|
|
|
|
return true;
|
|
}
|
|
|
|
/// CombineToPostIndexedLoadStore - Try combine a load / store with a
|
|
/// add / sub of the base pointer node into a post-indexed load / store.
|
|
/// The transformation folded the add / subtract into the new indexed
|
|
/// load / store effectively and all of its uses are redirected to the
|
|
/// new load / store.
|
|
bool DAGCombiner::CombineToPostIndexedLoadStore(SDNode *N) {
|
|
if (!AfterLegalize)
|
|
return false;
|
|
|
|
bool isLoad = true;
|
|
SDOperand Ptr;
|
|
MVT::ValueType VT;
|
|
if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
|
|
if (LD->getAddressingMode() != ISD::UNINDEXED)
|
|
return false;
|
|
VT = LD->getLoadedVT();
|
|
if (!TLI.isIndexedLoadLegal(ISD::POST_INC, VT) &&
|
|
!TLI.isIndexedLoadLegal(ISD::POST_DEC, VT))
|
|
return false;
|
|
Ptr = LD->getBasePtr();
|
|
} else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
|
|
if (ST->getAddressingMode() != ISD::UNINDEXED)
|
|
return false;
|
|
VT = ST->getStoredVT();
|
|
if (!TLI.isIndexedStoreLegal(ISD::POST_INC, VT) &&
|
|
!TLI.isIndexedStoreLegal(ISD::POST_DEC, VT))
|
|
return false;
|
|
Ptr = ST->getBasePtr();
|
|
isLoad = false;
|
|
} else
|
|
return false;
|
|
|
|
if (Ptr.Val->hasOneUse())
|
|
return false;
|
|
|
|
for (SDNode::use_iterator I = Ptr.Val->use_begin(),
|
|
E = Ptr.Val->use_end(); I != E; ++I) {
|
|
SDNode *Op = *I;
|
|
if (Op == N ||
|
|
(Op->getOpcode() != ISD::ADD && Op->getOpcode() != ISD::SUB))
|
|
continue;
|
|
|
|
SDOperand BasePtr;
|
|
SDOperand Offset;
|
|
ISD::MemIndexedMode AM = ISD::UNINDEXED;
|
|
if (TLI.getPostIndexedAddressParts(N, Op, BasePtr, Offset, AM, DAG)) {
|
|
if (Ptr == Offset)
|
|
std::swap(BasePtr, Offset);
|
|
if (Ptr != BasePtr)
|
|
continue;
|
|
// Don't create a indexed load / store with zero offset.
|
|
if (isa<ConstantSDNode>(Offset) &&
|
|
cast<ConstantSDNode>(Offset)->getValue() == 0)
|
|
continue;
|
|
|
|
// Try turning it into a post-indexed load / store except when
|
|
// 1) All uses are load / store ops that use it as base ptr.
|
|
// 2) Op must be independent of N, i.e. Op is neither a predecessor
|
|
// nor a successor of N. Otherwise, if Op is folded that would
|
|
// create a cycle.
|
|
|
|
// Check for #1.
|
|
bool TryNext = false;
|
|
for (SDNode::use_iterator II = BasePtr.Val->use_begin(),
|
|
EE = BasePtr.Val->use_end(); II != EE; ++II) {
|
|
SDNode *Use = *II;
|
|
if (Use == Ptr.Val)
|
|
continue;
|
|
|
|
// If all the uses are load / store addresses, then don't do the
|
|
// transformation.
|
|
if (Use->getOpcode() == ISD::ADD || Use->getOpcode() == ISD::SUB){
|
|
bool RealUse = false;
|
|
for (SDNode::use_iterator III = Use->use_begin(),
|
|
EEE = Use->use_end(); III != EEE; ++III) {
|
|
SDNode *UseUse = *III;
|
|
if (!((UseUse->getOpcode() == ISD::LOAD &&
|
|
cast<LoadSDNode>(UseUse)->getBasePtr().Val == Use) ||
|
|
(UseUse->getOpcode() == ISD::STORE) &&
|
|
cast<StoreSDNode>(UseUse)->getBasePtr().Val == Use))
|
|
RealUse = true;
|
|
}
|
|
|
|
if (!RealUse) {
|
|
TryNext = true;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
if (TryNext)
|
|
continue;
|
|
|
|
// Check for #2
|
|
if (!Op->isPredecessor(N) && !N->isPredecessor(Op)) {
|
|
SDOperand Result = isLoad
|
|
? DAG.getIndexedLoad(SDOperand(N,0), BasePtr, Offset, AM)
|
|
: DAG.getIndexedStore(SDOperand(N,0), BasePtr, Offset, AM);
|
|
++PostIndexedNodes;
|
|
++NodesCombined;
|
|
DOUT << "\nReplacing.5 "; DEBUG(N->dump(&DAG));
|
|
DOUT << "\nWith: "; DEBUG(Result.Val->dump(&DAG));
|
|
DOUT << '\n';
|
|
std::vector<SDNode*> NowDead;
|
|
if (isLoad) {
|
|
DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 0), Result.getValue(0),
|
|
&NowDead);
|
|
DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 1), Result.getValue(2),
|
|
&NowDead);
|
|
} else {
|
|
DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 0), Result.getValue(1),
|
|
&NowDead);
|
|
}
|
|
|
|
// Nodes can end up on the worklist more than once. Make sure we do
|
|
// not process a node that has been replaced.
|
|
for (unsigned i = 0, e = NowDead.size(); i != e; ++i)
|
|
removeFromWorkList(NowDead[i]);
|
|
// Finally, since the node is now dead, remove it from the graph.
|
|
DAG.DeleteNode(N);
|
|
|
|
// Replace the uses of Use with uses of the updated base value.
|
|
DAG.ReplaceAllUsesOfValueWith(SDOperand(Op, 0),
|
|
Result.getValue(isLoad ? 1 : 0),
|
|
&NowDead);
|
|
removeFromWorkList(Op);
|
|
for (unsigned i = 0, e = NowDead.size(); i != e; ++i)
|
|
removeFromWorkList(NowDead[i]);
|
|
DAG.DeleteNode(Op);
|
|
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
|
|
SDOperand DAGCombiner::visitLOAD(SDNode *N) {
|
|
LoadSDNode *LD = cast<LoadSDNode>(N);
|
|
SDOperand Chain = LD->getChain();
|
|
SDOperand Ptr = LD->getBasePtr();
|
|
|
|
// If load is not volatile and there are no uses of the loaded value (and
|
|
// the updated indexed value in case of indexed loads), change uses of the
|
|
// chain value into uses of the chain input (i.e. delete the dead load).
|
|
if (!LD->isVolatile()) {
|
|
if (N->getValueType(1) == MVT::Other) {
|
|
// Unindexed loads.
|
|
if (N->hasNUsesOfValue(0, 0))
|
|
return CombineTo(N, DAG.getNode(ISD::UNDEF, N->getValueType(0)), Chain);
|
|
} else {
|
|
// Indexed loads.
|
|
assert(N->getValueType(2) == MVT::Other && "Malformed indexed loads?");
|
|
if (N->hasNUsesOfValue(0, 0) && N->hasNUsesOfValue(0, 1)) {
|
|
SDOperand Undef0 = DAG.getNode(ISD::UNDEF, N->getValueType(0));
|
|
SDOperand Undef1 = DAG.getNode(ISD::UNDEF, N->getValueType(1));
|
|
SDOperand To[] = { Undef0, Undef1, Chain };
|
|
return CombineTo(N, To, 3);
|
|
}
|
|
}
|
|
}
|
|
|
|
// If this load is directly stored, replace the load value with the stored
|
|
// value.
|
|
// TODO: Handle store large -> read small portion.
|
|
// TODO: Handle TRUNCSTORE/LOADEXT
|
|
if (LD->getExtensionType() == ISD::NON_EXTLOAD) {
|
|
if (ISD::isNON_TRUNCStore(Chain.Val)) {
|
|
StoreSDNode *PrevST = cast<StoreSDNode>(Chain);
|
|
if (PrevST->getBasePtr() == Ptr &&
|
|
PrevST->getValue().getValueType() == N->getValueType(0))
|
|
return CombineTo(N, Chain.getOperand(1), Chain);
|
|
}
|
|
}
|
|
|
|
if (CombinerAA) {
|
|
// Walk up chain skipping non-aliasing memory nodes.
|
|
SDOperand BetterChain = FindBetterChain(N, Chain);
|
|
|
|
// If there is a better chain.
|
|
if (Chain != BetterChain) {
|
|
SDOperand ReplLoad;
|
|
|
|
// Replace the chain to void dependency.
|
|
if (LD->getExtensionType() == ISD::NON_EXTLOAD) {
|
|
ReplLoad = DAG.getLoad(N->getValueType(0), BetterChain, Ptr,
|
|
LD->getSrcValue(), LD->getSrcValueOffset(),
|
|
LD->isVolatile(), LD->getAlignment());
|
|
} else {
|
|
ReplLoad = DAG.getExtLoad(LD->getExtensionType(),
|
|
LD->getValueType(0),
|
|
BetterChain, Ptr, LD->getSrcValue(),
|
|
LD->getSrcValueOffset(),
|
|
LD->getLoadedVT(),
|
|
LD->isVolatile(),
|
|
LD->getAlignment());
|
|
}
|
|
|
|
// Create token factor to keep old chain connected.
|
|
SDOperand Token = DAG.getNode(ISD::TokenFactor, MVT::Other,
|
|
Chain, ReplLoad.getValue(1));
|
|
|
|
// Replace uses with load result and token factor. Don't add users
|
|
// to work list.
|
|
return CombineTo(N, ReplLoad.getValue(0), Token, false);
|
|
}
|
|
}
|
|
|
|
// Try transforming N to an indexed load.
|
|
if (CombineToPreIndexedLoadStore(N) || CombineToPostIndexedLoadStore(N))
|
|
return SDOperand(N, 0);
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitSTORE(SDNode *N) {
|
|
StoreSDNode *ST = cast<StoreSDNode>(N);
|
|
SDOperand Chain = ST->getChain();
|
|
SDOperand Value = ST->getValue();
|
|
SDOperand Ptr = ST->getBasePtr();
|
|
|
|
// If this is a store of a bit convert, store the input value if the
|
|
// resultant store does not need a higher alignment than the original.
|
|
if (Value.getOpcode() == ISD::BIT_CONVERT && !ST->isTruncatingStore() &&
|
|
ST->getAddressingMode() == ISD::UNINDEXED) {
|
|
unsigned Align = ST->getAlignment();
|
|
MVT::ValueType SVT = Value.getOperand(0).getValueType();
|
|
unsigned OrigAlign = TLI.getTargetMachine().getTargetData()->
|
|
getABITypeAlignment(MVT::getTypeForValueType(SVT));
|
|
if (Align <= OrigAlign && TLI.isOperationLegal(ISD::STORE, SVT))
|
|
return DAG.getStore(Chain, Value.getOperand(0), Ptr, ST->getSrcValue(),
|
|
ST->getSrcValueOffset(), ST->isVolatile(), Align);
|
|
}
|
|
|
|
// Turn 'store float 1.0, Ptr' -> 'store int 0x12345678, Ptr'
|
|
if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(Value)) {
|
|
if (Value.getOpcode() != ISD::TargetConstantFP) {
|
|
SDOperand Tmp;
|
|
switch (CFP->getValueType(0)) {
|
|
default: assert(0 && "Unknown FP type");
|
|
case MVT::f80: // We don't do this for these yet.
|
|
case MVT::f128:
|
|
case MVT::ppcf128:
|
|
break;
|
|
case MVT::f32:
|
|
if (!AfterLegalize || TLI.isTypeLegal(MVT::i32)) {
|
|
Tmp = DAG.getConstant((uint32_t)CFP->getValueAPF().
|
|
convertToAPInt().getZExtValue(), MVT::i32);
|
|
return DAG.getStore(Chain, Tmp, Ptr, ST->getSrcValue(),
|
|
ST->getSrcValueOffset(), ST->isVolatile(),
|
|
ST->getAlignment());
|
|
}
|
|
break;
|
|
case MVT::f64:
|
|
if (!AfterLegalize || TLI.isTypeLegal(MVT::i64)) {
|
|
Tmp = DAG.getConstant(CFP->getValueAPF().convertToAPInt().
|
|
getZExtValue(), MVT::i64);
|
|
return DAG.getStore(Chain, Tmp, Ptr, ST->getSrcValue(),
|
|
ST->getSrcValueOffset(), ST->isVolatile(),
|
|
ST->getAlignment());
|
|
} else if (TLI.isTypeLegal(MVT::i32)) {
|
|
// Many FP stores are not make apparent until after legalize, e.g. for
|
|
// argument passing. Since this is so common, custom legalize the
|
|
// 64-bit integer store into two 32-bit stores.
|
|
uint64_t Val = CFP->getValueAPF().convertToAPInt().getZExtValue();
|
|
SDOperand Lo = DAG.getConstant(Val & 0xFFFFFFFF, MVT::i32);
|
|
SDOperand Hi = DAG.getConstant(Val >> 32, MVT::i32);
|
|
if (!TLI.isLittleEndian()) std::swap(Lo, Hi);
|
|
|
|
int SVOffset = ST->getSrcValueOffset();
|
|
unsigned Alignment = ST->getAlignment();
|
|
bool isVolatile = ST->isVolatile();
|
|
|
|
SDOperand St0 = DAG.getStore(Chain, Lo, Ptr, ST->getSrcValue(),
|
|
ST->getSrcValueOffset(),
|
|
isVolatile, ST->getAlignment());
|
|
Ptr = DAG.getNode(ISD::ADD, Ptr.getValueType(), Ptr,
|
|
DAG.getConstant(4, Ptr.getValueType()));
|
|
SVOffset += 4;
|
|
if (Alignment > 4)
|
|
Alignment = 4;
|
|
SDOperand St1 = DAG.getStore(Chain, Hi, Ptr, ST->getSrcValue(),
|
|
SVOffset, isVolatile, Alignment);
|
|
return DAG.getNode(ISD::TokenFactor, MVT::Other, St0, St1);
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (CombinerAA) {
|
|
// Walk up chain skipping non-aliasing memory nodes.
|
|
SDOperand BetterChain = FindBetterChain(N, Chain);
|
|
|
|
// If there is a better chain.
|
|
if (Chain != BetterChain) {
|
|
// Replace the chain to avoid dependency.
|
|
SDOperand ReplStore;
|
|
if (ST->isTruncatingStore()) {
|
|
ReplStore = DAG.getTruncStore(BetterChain, Value, Ptr,
|
|
ST->getSrcValue(), ST->getSrcValueOffset(), ST->getStoredVT(),
|
|
ST->isVolatile(), ST->getAlignment());
|
|
} else {
|
|
ReplStore = DAG.getStore(BetterChain, Value, Ptr,
|
|
ST->getSrcValue(), ST->getSrcValueOffset(),
|
|
ST->isVolatile(), ST->getAlignment());
|
|
}
|
|
|
|
// Create token to keep both nodes around.
|
|
SDOperand Token =
|
|
DAG.getNode(ISD::TokenFactor, MVT::Other, Chain, ReplStore);
|
|
|
|
// Don't add users to work list.
|
|
return CombineTo(N, Token, false);
|
|
}
|
|
}
|
|
|
|
// Try transforming N to an indexed store.
|
|
if (CombineToPreIndexedLoadStore(N) || CombineToPostIndexedLoadStore(N))
|
|
return SDOperand(N, 0);
|
|
|
|
// FIXME: is there such a think as a truncating indexed store?
|
|
if (ST->isTruncatingStore() && ST->getAddressingMode() == ISD::UNINDEXED &&
|
|
MVT::isInteger(Value.getValueType())) {
|
|
// See if we can simplify the input to this truncstore with knowledge that
|
|
// only the low bits are being used. For example:
|
|
// "truncstore (or (shl x, 8), y), i8" -> "truncstore y, i8"
|
|
SDOperand Shorter =
|
|
GetDemandedBits(Value, MVT::getIntVTBitMask(ST->getStoredVT()));
|
|
AddToWorkList(Value.Val);
|
|
if (Shorter.Val)
|
|
return DAG.getTruncStore(Chain, Shorter, Ptr, ST->getSrcValue(),
|
|
ST->getSrcValueOffset(), ST->getStoredVT(),
|
|
ST->isVolatile(), ST->getAlignment());
|
|
|
|
// Otherwise, see if we can simplify the operation with
|
|
// SimplifyDemandedBits, which only works if the value has a single use.
|
|
if (SimplifyDemandedBits(Value, MVT::getIntVTBitMask(ST->getStoredVT())))
|
|
return SDOperand(N, 0);
|
|
}
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitINSERT_VECTOR_ELT(SDNode *N) {
|
|
SDOperand InVec = N->getOperand(0);
|
|
SDOperand InVal = N->getOperand(1);
|
|
SDOperand EltNo = N->getOperand(2);
|
|
|
|
// If the invec is a BUILD_VECTOR and if EltNo is a constant, build a new
|
|
// vector with the inserted element.
|
|
if (InVec.getOpcode() == ISD::BUILD_VECTOR && isa<ConstantSDNode>(EltNo)) {
|
|
unsigned Elt = cast<ConstantSDNode>(EltNo)->getValue();
|
|
SmallVector<SDOperand, 8> Ops(InVec.Val->op_begin(), InVec.Val->op_end());
|
|
if (Elt < Ops.size())
|
|
Ops[Elt] = InVal;
|
|
return DAG.getNode(ISD::BUILD_VECTOR, InVec.getValueType(),
|
|
&Ops[0], Ops.size());
|
|
}
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitEXTRACT_VECTOR_ELT(SDNode *N) {
|
|
SDOperand InVec = N->getOperand(0);
|
|
SDOperand EltNo = N->getOperand(1);
|
|
|
|
// (vextract (v4f32 s2v (f32 load $addr)), 0) -> (f32 load $addr)
|
|
// (vextract (v4i32 bc (v4f32 s2v (f32 load $addr))), 0) -> (i32 load $addr)
|
|
if (isa<ConstantSDNode>(EltNo)) {
|
|
unsigned Elt = cast<ConstantSDNode>(EltNo)->getValue();
|
|
bool NewLoad = false;
|
|
if (Elt == 0) {
|
|
MVT::ValueType VT = InVec.getValueType();
|
|
MVT::ValueType EVT = MVT::getVectorElementType(VT);
|
|
MVT::ValueType LVT = EVT;
|
|
unsigned NumElts = MVT::getVectorNumElements(VT);
|
|
if (InVec.getOpcode() == ISD::BIT_CONVERT) {
|
|
MVT::ValueType BCVT = InVec.getOperand(0).getValueType();
|
|
if (NumElts != MVT::getVectorNumElements(BCVT))
|
|
return SDOperand();
|
|
InVec = InVec.getOperand(0);
|
|
EVT = MVT::getVectorElementType(BCVT);
|
|
NewLoad = true;
|
|
}
|
|
if (InVec.getOpcode() == ISD::SCALAR_TO_VECTOR &&
|
|
InVec.getOperand(0).getValueType() == EVT &&
|
|
ISD::isNormalLoad(InVec.getOperand(0).Val) &&
|
|
InVec.getOperand(0).hasOneUse()) {
|
|
LoadSDNode *LN0 = cast<LoadSDNode>(InVec.getOperand(0));
|
|
unsigned Align = LN0->getAlignment();
|
|
if (NewLoad) {
|
|
// Check the resultant load doesn't need a higher alignment than the
|
|
// original load.
|
|
unsigned NewAlign = TLI.getTargetMachine().getTargetData()->
|
|
getABITypeAlignment(MVT::getTypeForValueType(LVT));
|
|
if (!TLI.isOperationLegal(ISD::LOAD, LVT) || NewAlign > Align)
|
|
return SDOperand();
|
|
Align = NewAlign;
|
|
}
|
|
|
|
return DAG.getLoad(LVT, LN0->getChain(), LN0->getBasePtr(),
|
|
LN0->getSrcValue(), LN0->getSrcValueOffset(),
|
|
LN0->isVolatile(), Align);
|
|
}
|
|
}
|
|
}
|
|
return SDOperand();
|
|
}
|
|
|
|
|
|
SDOperand DAGCombiner::visitBUILD_VECTOR(SDNode *N) {
|
|
unsigned NumInScalars = N->getNumOperands();
|
|
MVT::ValueType VT = N->getValueType(0);
|
|
unsigned NumElts = MVT::getVectorNumElements(VT);
|
|
MVT::ValueType EltType = MVT::getVectorElementType(VT);
|
|
|
|
// Check to see if this is a BUILD_VECTOR of a bunch of EXTRACT_VECTOR_ELT
|
|
// operations. If so, and if the EXTRACT_VECTOR_ELT vector inputs come from
|
|
// at most two distinct vectors, turn this into a shuffle node.
|
|
SDOperand VecIn1, VecIn2;
|
|
for (unsigned i = 0; i != NumInScalars; ++i) {
|
|
// Ignore undef inputs.
|
|
if (N->getOperand(i).getOpcode() == ISD::UNDEF) continue;
|
|
|
|
// If this input is something other than a EXTRACT_VECTOR_ELT with a
|
|
// constant index, bail out.
|
|
if (N->getOperand(i).getOpcode() != ISD::EXTRACT_VECTOR_ELT ||
|
|
!isa<ConstantSDNode>(N->getOperand(i).getOperand(1))) {
|
|
VecIn1 = VecIn2 = SDOperand(0, 0);
|
|
break;
|
|
}
|
|
|
|
// If the input vector type disagrees with the result of the build_vector,
|
|
// we can't make a shuffle.
|
|
SDOperand ExtractedFromVec = N->getOperand(i).getOperand(0);
|
|
if (ExtractedFromVec.getValueType() != VT) {
|
|
VecIn1 = VecIn2 = SDOperand(0, 0);
|
|
break;
|
|
}
|
|
|
|
// Otherwise, remember this. We allow up to two distinct input vectors.
|
|
if (ExtractedFromVec == VecIn1 || ExtractedFromVec == VecIn2)
|
|
continue;
|
|
|
|
if (VecIn1.Val == 0) {
|
|
VecIn1 = ExtractedFromVec;
|
|
} else if (VecIn2.Val == 0) {
|
|
VecIn2 = ExtractedFromVec;
|
|
} else {
|
|
// Too many inputs.
|
|
VecIn1 = VecIn2 = SDOperand(0, 0);
|
|
break;
|
|
}
|
|
}
|
|
|
|
// If everything is good, we can make a shuffle operation.
|
|
if (VecIn1.Val) {
|
|
SmallVector<SDOperand, 8> BuildVecIndices;
|
|
for (unsigned i = 0; i != NumInScalars; ++i) {
|
|
if (N->getOperand(i).getOpcode() == ISD::UNDEF) {
|
|
BuildVecIndices.push_back(DAG.getNode(ISD::UNDEF, TLI.getPointerTy()));
|
|
continue;
|
|
}
|
|
|
|
SDOperand Extract = N->getOperand(i);
|
|
|
|
// If extracting from the first vector, just use the index directly.
|
|
if (Extract.getOperand(0) == VecIn1) {
|
|
BuildVecIndices.push_back(Extract.getOperand(1));
|
|
continue;
|
|
}
|
|
|
|
// Otherwise, use InIdx + VecSize
|
|
unsigned Idx = cast<ConstantSDNode>(Extract.getOperand(1))->getValue();
|
|
BuildVecIndices.push_back(DAG.getConstant(Idx+NumInScalars,
|
|
TLI.getPointerTy()));
|
|
}
|
|
|
|
// Add count and size info.
|
|
MVT::ValueType BuildVecVT =
|
|
MVT::getVectorType(TLI.getPointerTy(), NumElts);
|
|
|
|
// Return the new VECTOR_SHUFFLE node.
|
|
SDOperand Ops[5];
|
|
Ops[0] = VecIn1;
|
|
if (VecIn2.Val) {
|
|
Ops[1] = VecIn2;
|
|
} else {
|
|
// Use an undef build_vector as input for the second operand.
|
|
std::vector<SDOperand> UnOps(NumInScalars,
|
|
DAG.getNode(ISD::UNDEF,
|
|
EltType));
|
|
Ops[1] = DAG.getNode(ISD::BUILD_VECTOR, VT,
|
|
&UnOps[0], UnOps.size());
|
|
AddToWorkList(Ops[1].Val);
|
|
}
|
|
Ops[2] = DAG.getNode(ISD::BUILD_VECTOR, BuildVecVT,
|
|
&BuildVecIndices[0], BuildVecIndices.size());
|
|
return DAG.getNode(ISD::VECTOR_SHUFFLE, VT, Ops, 3);
|
|
}
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitCONCAT_VECTORS(SDNode *N) {
|
|
// TODO: Check to see if this is a CONCAT_VECTORS of a bunch of
|
|
// EXTRACT_SUBVECTOR operations. If so, and if the EXTRACT_SUBVECTOR vector
|
|
// inputs come from at most two distinct vectors, turn this into a shuffle
|
|
// node.
|
|
|
|
// If we only have one input vector, we don't need to do any concatenation.
|
|
if (N->getNumOperands() == 1) {
|
|
return N->getOperand(0);
|
|
}
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::visitVECTOR_SHUFFLE(SDNode *N) {
|
|
SDOperand ShufMask = N->getOperand(2);
|
|
unsigned NumElts = ShufMask.getNumOperands();
|
|
|
|
// If the shuffle mask is an identity operation on the LHS, return the LHS.
|
|
bool isIdentity = true;
|
|
for (unsigned i = 0; i != NumElts; ++i) {
|
|
if (ShufMask.getOperand(i).getOpcode() != ISD::UNDEF &&
|
|
cast<ConstantSDNode>(ShufMask.getOperand(i))->getValue() != i) {
|
|
isIdentity = false;
|
|
break;
|
|
}
|
|
}
|
|
if (isIdentity) return N->getOperand(0);
|
|
|
|
// If the shuffle mask is an identity operation on the RHS, return the RHS.
|
|
isIdentity = true;
|
|
for (unsigned i = 0; i != NumElts; ++i) {
|
|
if (ShufMask.getOperand(i).getOpcode() != ISD::UNDEF &&
|
|
cast<ConstantSDNode>(ShufMask.getOperand(i))->getValue() != i+NumElts) {
|
|
isIdentity = false;
|
|
break;
|
|
}
|
|
}
|
|
if (isIdentity) return N->getOperand(1);
|
|
|
|
// Check if the shuffle is a unary shuffle, i.e. one of the vectors is not
|
|
// needed at all.
|
|
bool isUnary = true;
|
|
bool isSplat = true;
|
|
int VecNum = -1;
|
|
unsigned BaseIdx = 0;
|
|
for (unsigned i = 0; i != NumElts; ++i)
|
|
if (ShufMask.getOperand(i).getOpcode() != ISD::UNDEF) {
|
|
unsigned Idx = cast<ConstantSDNode>(ShufMask.getOperand(i))->getValue();
|
|
int V = (Idx < NumElts) ? 0 : 1;
|
|
if (VecNum == -1) {
|
|
VecNum = V;
|
|
BaseIdx = Idx;
|
|
} else {
|
|
if (BaseIdx != Idx)
|
|
isSplat = false;
|
|
if (VecNum != V) {
|
|
isUnary = false;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
SDOperand N0 = N->getOperand(0);
|
|
SDOperand N1 = N->getOperand(1);
|
|
// Normalize unary shuffle so the RHS is undef.
|
|
if (isUnary && VecNum == 1)
|
|
std::swap(N0, N1);
|
|
|
|
// If it is a splat, check if the argument vector is a build_vector with
|
|
// all scalar elements the same.
|
|
if (isSplat) {
|
|
SDNode *V = N0.Val;
|
|
|
|
// If this is a bit convert that changes the element type of the vector but
|
|
// not the number of vector elements, look through it. Be careful not to
|
|
// look though conversions that change things like v4f32 to v2f64.
|
|
if (V->getOpcode() == ISD::BIT_CONVERT) {
|
|
SDOperand ConvInput = V->getOperand(0);
|
|
if (MVT::getVectorNumElements(ConvInput.getValueType()) == NumElts)
|
|
V = ConvInput.Val;
|
|
}
|
|
|
|
if (V->getOpcode() == ISD::BUILD_VECTOR) {
|
|
unsigned NumElems = V->getNumOperands();
|
|
if (NumElems > BaseIdx) {
|
|
SDOperand Base;
|
|
bool AllSame = true;
|
|
for (unsigned i = 0; i != NumElems; ++i) {
|
|
if (V->getOperand(i).getOpcode() != ISD::UNDEF) {
|
|
Base = V->getOperand(i);
|
|
break;
|
|
}
|
|
}
|
|
// Splat of <u, u, u, u>, return <u, u, u, u>
|
|
if (!Base.Val)
|
|
return N0;
|
|
for (unsigned i = 0; i != NumElems; ++i) {
|
|
if (V->getOperand(i) != Base) {
|
|
AllSame = false;
|
|
break;
|
|
}
|
|
}
|
|
// Splat of <x, x, x, x>, return <x, x, x, x>
|
|
if (AllSame)
|
|
return N0;
|
|
}
|
|
}
|
|
}
|
|
|
|
// If it is a unary or the LHS and the RHS are the same node, turn the RHS
|
|
// into an undef.
|
|
if (isUnary || N0 == N1) {
|
|
// Check the SHUFFLE mask, mapping any inputs from the 2nd operand into the
|
|
// first operand.
|
|
SmallVector<SDOperand, 8> MappedOps;
|
|
for (unsigned i = 0; i != NumElts; ++i) {
|
|
if (ShufMask.getOperand(i).getOpcode() == ISD::UNDEF ||
|
|
cast<ConstantSDNode>(ShufMask.getOperand(i))->getValue() < NumElts) {
|
|
MappedOps.push_back(ShufMask.getOperand(i));
|
|
} else {
|
|
unsigned NewIdx =
|
|
cast<ConstantSDNode>(ShufMask.getOperand(i))->getValue() - NumElts;
|
|
MappedOps.push_back(DAG.getConstant(NewIdx, MVT::i32));
|
|
}
|
|
}
|
|
ShufMask = DAG.getNode(ISD::BUILD_VECTOR, ShufMask.getValueType(),
|
|
&MappedOps[0], MappedOps.size());
|
|
AddToWorkList(ShufMask.Val);
|
|
return DAG.getNode(ISD::VECTOR_SHUFFLE, N->getValueType(0),
|
|
N0,
|
|
DAG.getNode(ISD::UNDEF, N->getValueType(0)),
|
|
ShufMask);
|
|
}
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
/// XformToShuffleWithZero - Returns a vector_shuffle if it able to transform
|
|
/// an AND to a vector_shuffle with the destination vector and a zero vector.
|
|
/// e.g. AND V, <0xffffffff, 0, 0xffffffff, 0>. ==>
|
|
/// vector_shuffle V, Zero, <0, 4, 2, 4>
|
|
SDOperand DAGCombiner::XformToShuffleWithZero(SDNode *N) {
|
|
SDOperand LHS = N->getOperand(0);
|
|
SDOperand RHS = N->getOperand(1);
|
|
if (N->getOpcode() == ISD::AND) {
|
|
if (RHS.getOpcode() == ISD::BIT_CONVERT)
|
|
RHS = RHS.getOperand(0);
|
|
if (RHS.getOpcode() == ISD::BUILD_VECTOR) {
|
|
std::vector<SDOperand> IdxOps;
|
|
unsigned NumOps = RHS.getNumOperands();
|
|
unsigned NumElts = NumOps;
|
|
MVT::ValueType EVT = MVT::getVectorElementType(RHS.getValueType());
|
|
for (unsigned i = 0; i != NumElts; ++i) {
|
|
SDOperand Elt = RHS.getOperand(i);
|
|
if (!isa<ConstantSDNode>(Elt))
|
|
return SDOperand();
|
|
else if (cast<ConstantSDNode>(Elt)->isAllOnesValue())
|
|
IdxOps.push_back(DAG.getConstant(i, EVT));
|
|
else if (cast<ConstantSDNode>(Elt)->isNullValue())
|
|
IdxOps.push_back(DAG.getConstant(NumElts, EVT));
|
|
else
|
|
return SDOperand();
|
|
}
|
|
|
|
// Let's see if the target supports this vector_shuffle.
|
|
if (!TLI.isVectorClearMaskLegal(IdxOps, EVT, DAG))
|
|
return SDOperand();
|
|
|
|
// Return the new VECTOR_SHUFFLE node.
|
|
MVT::ValueType VT = MVT::getVectorType(EVT, NumElts);
|
|
std::vector<SDOperand> Ops;
|
|
LHS = DAG.getNode(ISD::BIT_CONVERT, VT, LHS);
|
|
Ops.push_back(LHS);
|
|
AddToWorkList(LHS.Val);
|
|
std::vector<SDOperand> ZeroOps(NumElts, DAG.getConstant(0, EVT));
|
|
Ops.push_back(DAG.getNode(ISD::BUILD_VECTOR, VT,
|
|
&ZeroOps[0], ZeroOps.size()));
|
|
Ops.push_back(DAG.getNode(ISD::BUILD_VECTOR, VT,
|
|
&IdxOps[0], IdxOps.size()));
|
|
SDOperand Result = DAG.getNode(ISD::VECTOR_SHUFFLE, VT,
|
|
&Ops[0], Ops.size());
|
|
if (VT != LHS.getValueType()) {
|
|
Result = DAG.getNode(ISD::BIT_CONVERT, LHS.getValueType(), Result);
|
|
}
|
|
return Result;
|
|
}
|
|
}
|
|
return SDOperand();
|
|
}
|
|
|
|
/// SimplifyVBinOp - Visit a binary vector operation, like ADD.
|
|
SDOperand DAGCombiner::SimplifyVBinOp(SDNode *N) {
|
|
// After legalize, the target may be depending on adds and other
|
|
// binary ops to provide legal ways to construct constants or other
|
|
// things. Simplifying them may result in a loss of legality.
|
|
if (AfterLegalize) return SDOperand();
|
|
|
|
MVT::ValueType VT = N->getValueType(0);
|
|
assert(MVT::isVector(VT) && "SimplifyVBinOp only works on vectors!");
|
|
|
|
MVT::ValueType EltType = MVT::getVectorElementType(VT);
|
|
SDOperand LHS = N->getOperand(0);
|
|
SDOperand RHS = N->getOperand(1);
|
|
SDOperand Shuffle = XformToShuffleWithZero(N);
|
|
if (Shuffle.Val) return Shuffle;
|
|
|
|
// If the LHS and RHS are BUILD_VECTOR nodes, see if we can constant fold
|
|
// this operation.
|
|
if (LHS.getOpcode() == ISD::BUILD_VECTOR &&
|
|
RHS.getOpcode() == ISD::BUILD_VECTOR) {
|
|
SmallVector<SDOperand, 8> Ops;
|
|
for (unsigned i = 0, e = LHS.getNumOperands(); i != e; ++i) {
|
|
SDOperand LHSOp = LHS.getOperand(i);
|
|
SDOperand RHSOp = RHS.getOperand(i);
|
|
// If these two elements can't be folded, bail out.
|
|
if ((LHSOp.getOpcode() != ISD::UNDEF &&
|
|
LHSOp.getOpcode() != ISD::Constant &&
|
|
LHSOp.getOpcode() != ISD::ConstantFP) ||
|
|
(RHSOp.getOpcode() != ISD::UNDEF &&
|
|
RHSOp.getOpcode() != ISD::Constant &&
|
|
RHSOp.getOpcode() != ISD::ConstantFP))
|
|
break;
|
|
// Can't fold divide by zero.
|
|
if (N->getOpcode() == ISD::SDIV || N->getOpcode() == ISD::UDIV ||
|
|
N->getOpcode() == ISD::FDIV) {
|
|
if ((RHSOp.getOpcode() == ISD::Constant &&
|
|
cast<ConstantSDNode>(RHSOp.Val)->isNullValue()) ||
|
|
(RHSOp.getOpcode() == ISD::ConstantFP &&
|
|
cast<ConstantFPSDNode>(RHSOp.Val)->getValueAPF().isZero()))
|
|
break;
|
|
}
|
|
Ops.push_back(DAG.getNode(N->getOpcode(), EltType, LHSOp, RHSOp));
|
|
AddToWorkList(Ops.back().Val);
|
|
assert((Ops.back().getOpcode() == ISD::UNDEF ||
|
|
Ops.back().getOpcode() == ISD::Constant ||
|
|
Ops.back().getOpcode() == ISD::ConstantFP) &&
|
|
"Scalar binop didn't fold!");
|
|
}
|
|
|
|
if (Ops.size() == LHS.getNumOperands()) {
|
|
MVT::ValueType VT = LHS.getValueType();
|
|
return DAG.getNode(ISD::BUILD_VECTOR, VT, &Ops[0], Ops.size());
|
|
}
|
|
}
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
SDOperand DAGCombiner::SimplifySelect(SDOperand N0, SDOperand N1, SDOperand N2){
|
|
assert(N0.getOpcode() ==ISD::SETCC && "First argument must be a SetCC node!");
|
|
|
|
SDOperand SCC = SimplifySelectCC(N0.getOperand(0), N0.getOperand(1), N1, N2,
|
|
cast<CondCodeSDNode>(N0.getOperand(2))->get());
|
|
// If we got a simplified select_cc node back from SimplifySelectCC, then
|
|
// break it down into a new SETCC node, and a new SELECT node, and then return
|
|
// the SELECT node, since we were called with a SELECT node.
|
|
if (SCC.Val) {
|
|
// Check to see if we got a select_cc back (to turn into setcc/select).
|
|
// Otherwise, just return whatever node we got back, like fabs.
|
|
if (SCC.getOpcode() == ISD::SELECT_CC) {
|
|
SDOperand SETCC = DAG.getNode(ISD::SETCC, N0.getValueType(),
|
|
SCC.getOperand(0), SCC.getOperand(1),
|
|
SCC.getOperand(4));
|
|
AddToWorkList(SETCC.Val);
|
|
return DAG.getNode(ISD::SELECT, SCC.getValueType(), SCC.getOperand(2),
|
|
SCC.getOperand(3), SETCC);
|
|
}
|
|
return SCC;
|
|
}
|
|
return SDOperand();
|
|
}
|
|
|
|
/// SimplifySelectOps - Given a SELECT or a SELECT_CC node, where LHS and RHS
|
|
/// are the two values being selected between, see if we can simplify the
|
|
/// select. Callers of this should assume that TheSelect is deleted if this
|
|
/// returns true. As such, they should return the appropriate thing (e.g. the
|
|
/// node) back to the top-level of the DAG combiner loop to avoid it being
|
|
/// looked at.
|
|
///
|
|
bool DAGCombiner::SimplifySelectOps(SDNode *TheSelect, SDOperand LHS,
|
|
SDOperand RHS) {
|
|
|
|
// If this is a select from two identical things, try to pull the operation
|
|
// through the select.
|
|
if (LHS.getOpcode() == RHS.getOpcode() && LHS.hasOneUse() && RHS.hasOneUse()){
|
|
// If this is a load and the token chain is identical, replace the select
|
|
// of two loads with a load through a select of the address to load from.
|
|
// This triggers in things like "select bool X, 10.0, 123.0" after the FP
|
|
// constants have been dropped into the constant pool.
|
|
if (LHS.getOpcode() == ISD::LOAD &&
|
|
// Token chains must be identical.
|
|
LHS.getOperand(0) == RHS.getOperand(0)) {
|
|
LoadSDNode *LLD = cast<LoadSDNode>(LHS);
|
|
LoadSDNode *RLD = cast<LoadSDNode>(RHS);
|
|
|
|
// If this is an EXTLOAD, the VT's must match.
|
|
if (LLD->getLoadedVT() == RLD->getLoadedVT()) {
|
|
// FIXME: this conflates two src values, discarding one. This is not
|
|
// the right thing to do, but nothing uses srcvalues now. When they do,
|
|
// turn SrcValue into a list of locations.
|
|
SDOperand Addr;
|
|
if (TheSelect->getOpcode() == ISD::SELECT) {
|
|
// Check that the condition doesn't reach either load. If so, folding
|
|
// this will induce a cycle into the DAG.
|
|
if (!LLD->isPredecessor(TheSelect->getOperand(0).Val) &&
|
|
!RLD->isPredecessor(TheSelect->getOperand(0).Val)) {
|
|
Addr = DAG.getNode(ISD::SELECT, LLD->getBasePtr().getValueType(),
|
|
TheSelect->getOperand(0), LLD->getBasePtr(),
|
|
RLD->getBasePtr());
|
|
}
|
|
} else {
|
|
// Check that the condition doesn't reach either load. If so, folding
|
|
// this will induce a cycle into the DAG.
|
|
if (!LLD->isPredecessor(TheSelect->getOperand(0).Val) &&
|
|
!RLD->isPredecessor(TheSelect->getOperand(0).Val) &&
|
|
!LLD->isPredecessor(TheSelect->getOperand(1).Val) &&
|
|
!RLD->isPredecessor(TheSelect->getOperand(1).Val)) {
|
|
Addr = DAG.getNode(ISD::SELECT_CC, LLD->getBasePtr().getValueType(),
|
|
TheSelect->getOperand(0),
|
|
TheSelect->getOperand(1),
|
|
LLD->getBasePtr(), RLD->getBasePtr(),
|
|
TheSelect->getOperand(4));
|
|
}
|
|
}
|
|
|
|
if (Addr.Val) {
|
|
SDOperand Load;
|
|
if (LLD->getExtensionType() == ISD::NON_EXTLOAD)
|
|
Load = DAG.getLoad(TheSelect->getValueType(0), LLD->getChain(),
|
|
Addr,LLD->getSrcValue(),
|
|
LLD->getSrcValueOffset(),
|
|
LLD->isVolatile(),
|
|
LLD->getAlignment());
|
|
else {
|
|
Load = DAG.getExtLoad(LLD->getExtensionType(),
|
|
TheSelect->getValueType(0),
|
|
LLD->getChain(), Addr, LLD->getSrcValue(),
|
|
LLD->getSrcValueOffset(),
|
|
LLD->getLoadedVT(),
|
|
LLD->isVolatile(),
|
|
LLD->getAlignment());
|
|
}
|
|
// Users of the select now use the result of the load.
|
|
CombineTo(TheSelect, Load);
|
|
|
|
// Users of the old loads now use the new load's chain. We know the
|
|
// old-load value is dead now.
|
|
CombineTo(LHS.Val, Load.getValue(0), Load.getValue(1));
|
|
CombineTo(RHS.Val, Load.getValue(0), Load.getValue(1));
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
SDOperand DAGCombiner::SimplifySelectCC(SDOperand N0, SDOperand N1,
|
|
SDOperand N2, SDOperand N3,
|
|
ISD::CondCode CC, bool NotExtCompare) {
|
|
|
|
MVT::ValueType VT = N2.getValueType();
|
|
ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.Val);
|
|
ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2.Val);
|
|
ConstantSDNode *N3C = dyn_cast<ConstantSDNode>(N3.Val);
|
|
|
|
// Determine if the condition we're dealing with is constant
|
|
SDOperand SCC = SimplifySetCC(TLI.getSetCCResultTy(), N0, N1, CC, false);
|
|
if (SCC.Val) AddToWorkList(SCC.Val);
|
|
ConstantSDNode *SCCC = dyn_cast_or_null<ConstantSDNode>(SCC.Val);
|
|
|
|
// fold select_cc true, x, y -> x
|
|
if (SCCC && SCCC->getValue())
|
|
return N2;
|
|
// fold select_cc false, x, y -> y
|
|
if (SCCC && SCCC->getValue() == 0)
|
|
return N3;
|
|
|
|
// Check to see if we can simplify the select into an fabs node
|
|
if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(N1)) {
|
|
// Allow either -0.0 or 0.0
|
|
if (CFP->getValueAPF().isZero()) {
|
|
// select (setg[te] X, +/-0.0), X, fneg(X) -> fabs
|
|
if ((CC == ISD::SETGE || CC == ISD::SETGT) &&
|
|
N0 == N2 && N3.getOpcode() == ISD::FNEG &&
|
|
N2 == N3.getOperand(0))
|
|
return DAG.getNode(ISD::FABS, VT, N0);
|
|
|
|
// select (setl[te] X, +/-0.0), fneg(X), X -> fabs
|
|
if ((CC == ISD::SETLT || CC == ISD::SETLE) &&
|
|
N0 == N3 && N2.getOpcode() == ISD::FNEG &&
|
|
N2.getOperand(0) == N3)
|
|
return DAG.getNode(ISD::FABS, VT, N3);
|
|
}
|
|
}
|
|
|
|
// Check to see if we can perform the "gzip trick", transforming
|
|
// select_cc setlt X, 0, A, 0 -> and (sra X, size(X)-1), A
|
|
if (N1C && N3C && N3C->isNullValue() && CC == ISD::SETLT &&
|
|
MVT::isInteger(N0.getValueType()) &&
|
|
MVT::isInteger(N2.getValueType()) &&
|
|
(N1C->isNullValue() || // (a < 0) ? b : 0
|
|
(N1C->getValue() == 1 && N0 == N2))) { // (a < 1) ? a : 0
|
|
MVT::ValueType XType = N0.getValueType();
|
|
MVT::ValueType AType = N2.getValueType();
|
|
if (XType >= AType) {
|
|
// and (sra X, size(X)-1, A) -> "and (srl X, C2), A" iff A is a
|
|
// single-bit constant.
|
|
if (N2C && ((N2C->getValue() & (N2C->getValue()-1)) == 0)) {
|
|
unsigned ShCtV = Log2_64(N2C->getValue());
|
|
ShCtV = MVT::getSizeInBits(XType)-ShCtV-1;
|
|
SDOperand ShCt = DAG.getConstant(ShCtV, TLI.getShiftAmountTy());
|
|
SDOperand Shift = DAG.getNode(ISD::SRL, XType, N0, ShCt);
|
|
AddToWorkList(Shift.Val);
|
|
if (XType > AType) {
|
|
Shift = DAG.getNode(ISD::TRUNCATE, AType, Shift);
|
|
AddToWorkList(Shift.Val);
|
|
}
|
|
return DAG.getNode(ISD::AND, AType, Shift, N2);
|
|
}
|
|
SDOperand Shift = DAG.getNode(ISD::SRA, XType, N0,
|
|
DAG.getConstant(MVT::getSizeInBits(XType)-1,
|
|
TLI.getShiftAmountTy()));
|
|
AddToWorkList(Shift.Val);
|
|
if (XType > AType) {
|
|
Shift = DAG.getNode(ISD::TRUNCATE, AType, Shift);
|
|
AddToWorkList(Shift.Val);
|
|
}
|
|
return DAG.getNode(ISD::AND, AType, Shift, N2);
|
|
}
|
|
}
|
|
|
|
// fold select C, 16, 0 -> shl C, 4
|
|
if (N2C && N3C && N3C->isNullValue() && isPowerOf2_64(N2C->getValue()) &&
|
|
TLI.getSetCCResultContents() == TargetLowering::ZeroOrOneSetCCResult) {
|
|
|
|
// If the caller doesn't want us to simplify this into a zext of a compare,
|
|
// don't do it.
|
|
if (NotExtCompare && N2C->getValue() == 1)
|
|
return SDOperand();
|
|
|
|
// Get a SetCC of the condition
|
|
// FIXME: Should probably make sure that setcc is legal if we ever have a
|
|
// target where it isn't.
|
|
SDOperand Temp, SCC;
|
|
// cast from setcc result type to select result type
|
|
if (AfterLegalize) {
|
|
SCC = DAG.getSetCC(TLI.getSetCCResultTy(), N0, N1, CC);
|
|
if (N2.getValueType() < SCC.getValueType())
|
|
Temp = DAG.getZeroExtendInReg(SCC, N2.getValueType());
|
|
else
|
|
Temp = DAG.getNode(ISD::ZERO_EXTEND, N2.getValueType(), SCC);
|
|
} else {
|
|
SCC = DAG.getSetCC(MVT::i1, N0, N1, CC);
|
|
Temp = DAG.getNode(ISD::ZERO_EXTEND, N2.getValueType(), SCC);
|
|
}
|
|
AddToWorkList(SCC.Val);
|
|
AddToWorkList(Temp.Val);
|
|
|
|
if (N2C->getValue() == 1)
|
|
return Temp;
|
|
// shl setcc result by log2 n2c
|
|
return DAG.getNode(ISD::SHL, N2.getValueType(), Temp,
|
|
DAG.getConstant(Log2_64(N2C->getValue()),
|
|
TLI.getShiftAmountTy()));
|
|
}
|
|
|
|
// Check to see if this is the equivalent of setcc
|
|
// FIXME: Turn all of these into setcc if setcc if setcc is legal
|
|
// otherwise, go ahead with the folds.
|
|
if (0 && N3C && N3C->isNullValue() && N2C && (N2C->getValue() == 1ULL)) {
|
|
MVT::ValueType XType = N0.getValueType();
|
|
if (TLI.isOperationLegal(ISD::SETCC, TLI.getSetCCResultTy())) {
|
|
SDOperand Res = DAG.getSetCC(TLI.getSetCCResultTy(), N0, N1, CC);
|
|
if (Res.getValueType() != VT)
|
|
Res = DAG.getNode(ISD::ZERO_EXTEND, VT, Res);
|
|
return Res;
|
|
}
|
|
|
|
// seteq X, 0 -> srl (ctlz X, log2(size(X)))
|
|
if (N1C && N1C->isNullValue() && CC == ISD::SETEQ &&
|
|
TLI.isOperationLegal(ISD::CTLZ, XType)) {
|
|
SDOperand Ctlz = DAG.getNode(ISD::CTLZ, XType, N0);
|
|
return DAG.getNode(ISD::SRL, XType, Ctlz,
|
|
DAG.getConstant(Log2_32(MVT::getSizeInBits(XType)),
|
|
TLI.getShiftAmountTy()));
|
|
}
|
|
// setgt X, 0 -> srl (and (-X, ~X), size(X)-1)
|
|
if (N1C && N1C->isNullValue() && CC == ISD::SETGT) {
|
|
SDOperand NegN0 = DAG.getNode(ISD::SUB, XType, DAG.getConstant(0, XType),
|
|
N0);
|
|
SDOperand NotN0 = DAG.getNode(ISD::XOR, XType, N0,
|
|
DAG.getConstant(~0ULL, XType));
|
|
return DAG.getNode(ISD::SRL, XType,
|
|
DAG.getNode(ISD::AND, XType, NegN0, NotN0),
|
|
DAG.getConstant(MVT::getSizeInBits(XType)-1,
|
|
TLI.getShiftAmountTy()));
|
|
}
|
|
// setgt X, -1 -> xor (srl (X, size(X)-1), 1)
|
|
if (N1C && N1C->isAllOnesValue() && CC == ISD::SETGT) {
|
|
SDOperand Sign = DAG.getNode(ISD::SRL, XType, N0,
|
|
DAG.getConstant(MVT::getSizeInBits(XType)-1,
|
|
TLI.getShiftAmountTy()));
|
|
return DAG.getNode(ISD::XOR, XType, Sign, DAG.getConstant(1, XType));
|
|
}
|
|
}
|
|
|
|
// Check to see if this is an integer abs. select_cc setl[te] X, 0, -X, X ->
|
|
// Y = sra (X, size(X)-1); xor (add (X, Y), Y)
|
|
if (N1C && N1C->isNullValue() && (CC == ISD::SETLT || CC == ISD::SETLE) &&
|
|
N0 == N3 && N2.getOpcode() == ISD::SUB && N0 == N2.getOperand(1) &&
|
|
N2.getOperand(0) == N1 && MVT::isInteger(N0.getValueType())) {
|
|
MVT::ValueType XType = N0.getValueType();
|
|
SDOperand Shift = DAG.getNode(ISD::SRA, XType, N0,
|
|
DAG.getConstant(MVT::getSizeInBits(XType)-1,
|
|
TLI.getShiftAmountTy()));
|
|
SDOperand Add = DAG.getNode(ISD::ADD, XType, N0, Shift);
|
|
AddToWorkList(Shift.Val);
|
|
AddToWorkList(Add.Val);
|
|
return DAG.getNode(ISD::XOR, XType, Add, Shift);
|
|
}
|
|
// Check to see if this is an integer abs. select_cc setgt X, -1, X, -X ->
|
|
// Y = sra (X, size(X)-1); xor (add (X, Y), Y)
|
|
if (N1C && N1C->isAllOnesValue() && CC == ISD::SETGT &&
|
|
N0 == N2 && N3.getOpcode() == ISD::SUB && N0 == N3.getOperand(1)) {
|
|
if (ConstantSDNode *SubC = dyn_cast<ConstantSDNode>(N3.getOperand(0))) {
|
|
MVT::ValueType XType = N0.getValueType();
|
|
if (SubC->isNullValue() && MVT::isInteger(XType)) {
|
|
SDOperand Shift = DAG.getNode(ISD::SRA, XType, N0,
|
|
DAG.getConstant(MVT::getSizeInBits(XType)-1,
|
|
TLI.getShiftAmountTy()));
|
|
SDOperand Add = DAG.getNode(ISD::ADD, XType, N0, Shift);
|
|
AddToWorkList(Shift.Val);
|
|
AddToWorkList(Add.Val);
|
|
return DAG.getNode(ISD::XOR, XType, Add, Shift);
|
|
}
|
|
}
|
|
}
|
|
|
|
return SDOperand();
|
|
}
|
|
|
|
/// SimplifySetCC - This is a stub for TargetLowering::SimplifySetCC.
|
|
SDOperand DAGCombiner::SimplifySetCC(MVT::ValueType VT, SDOperand N0,
|
|
SDOperand N1, ISD::CondCode Cond,
|
|
bool foldBooleans) {
|
|
TargetLowering::DAGCombinerInfo
|
|
DagCombineInfo(DAG, !AfterLegalize, false, this);
|
|
return TLI.SimplifySetCC(VT, N0, N1, Cond, foldBooleans, DagCombineInfo);
|
|
}
|
|
|
|
/// BuildSDIVSequence - Given an ISD::SDIV node expressing a divide by constant,
|
|
/// return a DAG expression to select that will generate the same value by
|
|
/// multiplying by a magic number. See:
|
|
/// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
|
|
SDOperand DAGCombiner::BuildSDIV(SDNode *N) {
|
|
std::vector<SDNode*> Built;
|
|
SDOperand S = TLI.BuildSDIV(N, DAG, &Built);
|
|
|
|
for (std::vector<SDNode*>::iterator ii = Built.begin(), ee = Built.end();
|
|
ii != ee; ++ii)
|
|
AddToWorkList(*ii);
|
|
return S;
|
|
}
|
|
|
|
/// BuildUDIVSequence - Given an ISD::UDIV node expressing a divide by constant,
|
|
/// return a DAG expression to select that will generate the same value by
|
|
/// multiplying by a magic number. See:
|
|
/// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
|
|
SDOperand DAGCombiner::BuildUDIV(SDNode *N) {
|
|
std::vector<SDNode*> Built;
|
|
SDOperand S = TLI.BuildUDIV(N, DAG, &Built);
|
|
|
|
for (std::vector<SDNode*>::iterator ii = Built.begin(), ee = Built.end();
|
|
ii != ee; ++ii)
|
|
AddToWorkList(*ii);
|
|
return S;
|
|
}
|
|
|
|
/// FindBaseOffset - Return true if base is known not to alias with anything
|
|
/// but itself. Provides base object and offset as results.
|
|
static bool FindBaseOffset(SDOperand Ptr, SDOperand &Base, int64_t &Offset) {
|
|
// Assume it is a primitive operation.
|
|
Base = Ptr; Offset = 0;
|
|
|
|
// If it's an adding a simple constant then integrate the offset.
|
|
if (Base.getOpcode() == ISD::ADD) {
|
|
if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Base.getOperand(1))) {
|
|
Base = Base.getOperand(0);
|
|
Offset += C->getValue();
|
|
}
|
|
}
|
|
|
|
// If it's any of the following then it can't alias with anything but itself.
|
|
return isa<FrameIndexSDNode>(Base) ||
|
|
isa<ConstantPoolSDNode>(Base) ||
|
|
isa<GlobalAddressSDNode>(Base);
|
|
}
|
|
|
|
/// isAlias - Return true if there is any possibility that the two addresses
|
|
/// overlap.
|
|
bool DAGCombiner::isAlias(SDOperand Ptr1, int64_t Size1,
|
|
const Value *SrcValue1, int SrcValueOffset1,
|
|
SDOperand Ptr2, int64_t Size2,
|
|
const Value *SrcValue2, int SrcValueOffset2)
|
|
{
|
|
// If they are the same then they must be aliases.
|
|
if (Ptr1 == Ptr2) return true;
|
|
|
|
// Gather base node and offset information.
|
|
SDOperand Base1, Base2;
|
|
int64_t Offset1, Offset2;
|
|
bool KnownBase1 = FindBaseOffset(Ptr1, Base1, Offset1);
|
|
bool KnownBase2 = FindBaseOffset(Ptr2, Base2, Offset2);
|
|
|
|
// If they have a same base address then...
|
|
if (Base1 == Base2) {
|
|
// Check to see if the addresses overlap.
|
|
return!((Offset1 + Size1) <= Offset2 || (Offset2 + Size2) <= Offset1);
|
|
}
|
|
|
|
// If we know both bases then they can't alias.
|
|
if (KnownBase1 && KnownBase2) return false;
|
|
|
|
if (CombinerGlobalAA) {
|
|
// Use alias analysis information.
|
|
int64_t MinOffset = std::min(SrcValueOffset1, SrcValueOffset2);
|
|
int64_t Overlap1 = Size1 + SrcValueOffset1 - MinOffset;
|
|
int64_t Overlap2 = Size2 + SrcValueOffset2 - MinOffset;
|
|
AliasAnalysis::AliasResult AAResult =
|
|
AA.alias(SrcValue1, Overlap1, SrcValue2, Overlap2);
|
|
if (AAResult == AliasAnalysis::NoAlias)
|
|
return false;
|
|
}
|
|
|
|
// Otherwise we have to assume they alias.
|
|
return true;
|
|
}
|
|
|
|
/// FindAliasInfo - Extracts the relevant alias information from the memory
|
|
/// node. Returns true if the operand was a load.
|
|
bool DAGCombiner::FindAliasInfo(SDNode *N,
|
|
SDOperand &Ptr, int64_t &Size,
|
|
const Value *&SrcValue, int &SrcValueOffset) {
|
|
if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
|
|
Ptr = LD->getBasePtr();
|
|
Size = MVT::getSizeInBits(LD->getLoadedVT()) >> 3;
|
|
SrcValue = LD->getSrcValue();
|
|
SrcValueOffset = LD->getSrcValueOffset();
|
|
return true;
|
|
} else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
|
|
Ptr = ST->getBasePtr();
|
|
Size = MVT::getSizeInBits(ST->getStoredVT()) >> 3;
|
|
SrcValue = ST->getSrcValue();
|
|
SrcValueOffset = ST->getSrcValueOffset();
|
|
} else {
|
|
assert(0 && "FindAliasInfo expected a memory operand");
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/// GatherAllAliases - Walk up chain skipping non-aliasing memory nodes,
|
|
/// looking for aliasing nodes and adding them to the Aliases vector.
|
|
void DAGCombiner::GatherAllAliases(SDNode *N, SDOperand OriginalChain,
|
|
SmallVector<SDOperand, 8> &Aliases) {
|
|
SmallVector<SDOperand, 8> Chains; // List of chains to visit.
|
|
std::set<SDNode *> Visited; // Visited node set.
|
|
|
|
// Get alias information for node.
|
|
SDOperand Ptr;
|
|
int64_t Size;
|
|
const Value *SrcValue;
|
|
int SrcValueOffset;
|
|
bool IsLoad = FindAliasInfo(N, Ptr, Size, SrcValue, SrcValueOffset);
|
|
|
|
// Starting off.
|
|
Chains.push_back(OriginalChain);
|
|
|
|
// Look at each chain and determine if it is an alias. If so, add it to the
|
|
// aliases list. If not, then continue up the chain looking for the next
|
|
// candidate.
|
|
while (!Chains.empty()) {
|
|
SDOperand Chain = Chains.back();
|
|
Chains.pop_back();
|
|
|
|
// Don't bother if we've been before.
|
|
if (Visited.find(Chain.Val) != Visited.end()) continue;
|
|
Visited.insert(Chain.Val);
|
|
|
|
switch (Chain.getOpcode()) {
|
|
case ISD::EntryToken:
|
|
// Entry token is ideal chain operand, but handled in FindBetterChain.
|
|
break;
|
|
|
|
case ISD::LOAD:
|
|
case ISD::STORE: {
|
|
// Get alias information for Chain.
|
|
SDOperand OpPtr;
|
|
int64_t OpSize;
|
|
const Value *OpSrcValue;
|
|
int OpSrcValueOffset;
|
|
bool IsOpLoad = FindAliasInfo(Chain.Val, OpPtr, OpSize,
|
|
OpSrcValue, OpSrcValueOffset);
|
|
|
|
// If chain is alias then stop here.
|
|
if (!(IsLoad && IsOpLoad) &&
|
|
isAlias(Ptr, Size, SrcValue, SrcValueOffset,
|
|
OpPtr, OpSize, OpSrcValue, OpSrcValueOffset)) {
|
|
Aliases.push_back(Chain);
|
|
} else {
|
|
// Look further up the chain.
|
|
Chains.push_back(Chain.getOperand(0));
|
|
// Clean up old chain.
|
|
AddToWorkList(Chain.Val);
|
|
}
|
|
break;
|
|
}
|
|
|
|
case ISD::TokenFactor:
|
|
// We have to check each of the operands of the token factor, so we queue
|
|
// then up. Adding the operands to the queue (stack) in reverse order
|
|
// maintains the original order and increases the likelihood that getNode
|
|
// will find a matching token factor (CSE.)
|
|
for (unsigned n = Chain.getNumOperands(); n;)
|
|
Chains.push_back(Chain.getOperand(--n));
|
|
// Eliminate the token factor if we can.
|
|
AddToWorkList(Chain.Val);
|
|
break;
|
|
|
|
default:
|
|
// For all other instructions we will just have to take what we can get.
|
|
Aliases.push_back(Chain);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
/// FindBetterChain - Walk up chain skipping non-aliasing memory nodes, looking
|
|
/// for a better chain (aliasing node.)
|
|
SDOperand DAGCombiner::FindBetterChain(SDNode *N, SDOperand OldChain) {
|
|
SmallVector<SDOperand, 8> Aliases; // Ops for replacing token factor.
|
|
|
|
// Accumulate all the aliases to this node.
|
|
GatherAllAliases(N, OldChain, Aliases);
|
|
|
|
if (Aliases.size() == 0) {
|
|
// If no operands then chain to entry token.
|
|
return DAG.getEntryNode();
|
|
} else if (Aliases.size() == 1) {
|
|
// If a single operand then chain to it. We don't need to revisit it.
|
|
return Aliases[0];
|
|
}
|
|
|
|
// Construct a custom tailored token factor.
|
|
SDOperand NewChain = DAG.getNode(ISD::TokenFactor, MVT::Other,
|
|
&Aliases[0], Aliases.size());
|
|
|
|
// Make sure the old chain gets cleaned up.
|
|
if (NewChain != OldChain) AddToWorkList(OldChain.Val);
|
|
|
|
return NewChain;
|
|
}
|
|
|
|
// SelectionDAG::Combine - This is the entry point for the file.
|
|
//
|
|
void SelectionDAG::Combine(bool RunningAfterLegalize, AliasAnalysis &AA) {
|
|
if (!RunningAfterLegalize && ViewDAGCombine1)
|
|
viewGraph();
|
|
if (RunningAfterLegalize && ViewDAGCombine2)
|
|
viewGraph();
|
|
/// run - This is the main entry point to this class.
|
|
///
|
|
DAGCombiner(*this, AA).Run(RunningAfterLegalize);
|
|
}
|