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llvm-6502/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
Chris Lattner 319ef94030 remove dead code. 
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97529 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-02 00:40:26 +00:00

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//===-- SelectionDAGISel.cpp - Implement the SelectionDAGISel class -------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This implements the SelectionDAGISel class.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "isel"
#include "ScheduleDAGSDNodes.h"
#include "SelectionDAGBuilder.h"
#include "FunctionLoweringInfo.h"
#include "llvm/CodeGen/SelectionDAGISel.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/DebugInfo.h"
#include "llvm/Constants.h"
#include "llvm/CallingConv.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Function.h"
#include "llvm/GlobalVariable.h"
#include "llvm/InlineAsm.h"
#include "llvm/Instructions.h"
#include "llvm/Intrinsics.h"
#include "llvm/IntrinsicInst.h"
#include "llvm/LLVMContext.h"
#include "llvm/CodeGen/FastISel.h"
#include "llvm/CodeGen/GCStrategy.h"
#include "llvm/CodeGen/GCMetadata.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFunctionAnalysis.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineJumpTableInfo.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/ScheduleHazardRecognizer.h"
#include "llvm/CodeGen/SchedulerRegistry.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/CodeGen/DwarfWriter.h"
#include "llvm/Target/TargetRegisterInfo.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetFrameInfo.h"
#include "llvm/Target/TargetIntrinsicInfo.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetLowering.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/Timer.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
using namespace llvm;
static cl::opt<bool>
EnableFastISelVerbose("fast-isel-verbose", cl::Hidden,
cl::desc("Enable verbose messages in the \"fast\" "
"instruction selector"));
static cl::opt<bool>
EnableFastISelAbort("fast-isel-abort", cl::Hidden,
cl::desc("Enable abort calls when \"fast\" instruction fails"));
static cl::opt<bool>
SchedLiveInCopies("schedule-livein-copies", cl::Hidden,
cl::desc("Schedule copies of livein registers"),
cl::init(false));
#ifndef NDEBUG
static cl::opt<bool>
ViewDAGCombine1("view-dag-combine1-dags", cl::Hidden,
cl::desc("Pop up a window to show dags before the first "
"dag combine pass"));
static cl::opt<bool>
ViewLegalizeTypesDAGs("view-legalize-types-dags", cl::Hidden,
cl::desc("Pop up a window to show dags before legalize types"));
static cl::opt<bool>
ViewLegalizeDAGs("view-legalize-dags", cl::Hidden,
cl::desc("Pop up a window to show dags before legalize"));
static cl::opt<bool>
ViewDAGCombine2("view-dag-combine2-dags", cl::Hidden,
cl::desc("Pop up a window to show dags before the second "
"dag combine pass"));
static cl::opt<bool>
ViewDAGCombineLT("view-dag-combine-lt-dags", cl::Hidden,
cl::desc("Pop up a window to show dags before the post legalize types"
" dag combine pass"));
static cl::opt<bool>
ViewISelDAGs("view-isel-dags", cl::Hidden,
cl::desc("Pop up a window to show isel dags as they are selected"));
static cl::opt<bool>
ViewSchedDAGs("view-sched-dags", cl::Hidden,
cl::desc("Pop up a window to show sched dags as they are processed"));
static cl::opt<bool>
ViewSUnitDAGs("view-sunit-dags", cl::Hidden,
cl::desc("Pop up a window to show SUnit dags after they are processed"));
#else
static const bool ViewDAGCombine1 = false,
ViewLegalizeTypesDAGs = false, ViewLegalizeDAGs = false,
ViewDAGCombine2 = false,
ViewDAGCombineLT = false,
ViewISelDAGs = false, ViewSchedDAGs = false,
ViewSUnitDAGs = false;
#endif
//===---------------------------------------------------------------------===//
///
/// RegisterScheduler class - Track the registration of instruction schedulers.
///
//===---------------------------------------------------------------------===//
MachinePassRegistry RegisterScheduler::Registry;
//===---------------------------------------------------------------------===//
///
/// ISHeuristic command line option for instruction schedulers.
///
//===---------------------------------------------------------------------===//
static cl::opt<RegisterScheduler::FunctionPassCtor, false,
RegisterPassParser<RegisterScheduler> >
ISHeuristic("pre-RA-sched",
cl::init(&createDefaultScheduler),
cl::desc("Instruction schedulers available (before register"
" allocation):"));
static RegisterScheduler
defaultListDAGScheduler("default", "Best scheduler for the target",
createDefaultScheduler);
namespace llvm {
//===--------------------------------------------------------------------===//
/// createDefaultScheduler - This creates an instruction scheduler appropriate
/// for the target.
ScheduleDAGSDNodes* createDefaultScheduler(SelectionDAGISel *IS,
CodeGenOpt::Level OptLevel) {
const TargetLowering &TLI = IS->getTargetLowering();
if (OptLevel == CodeGenOpt::None)
return createFastDAGScheduler(IS, OptLevel);
if (TLI.getSchedulingPreference() == TargetLowering::SchedulingForLatency)
return createTDListDAGScheduler(IS, OptLevel);
assert(TLI.getSchedulingPreference() ==
TargetLowering::SchedulingForRegPressure && "Unknown sched type!");
return createBURRListDAGScheduler(IS, OptLevel);
}
}
// EmitInstrWithCustomInserter - This method should be implemented by targets
// that mark instructions with the 'usesCustomInserter' flag. These
// instructions are special in various ways, which require special support to
// insert. The specified MachineInstr is created but not inserted into any
// basic blocks, and this method is called to expand it into a sequence of
// instructions, potentially also creating new basic blocks and control flow.
// When new basic blocks are inserted and the edges from MBB to its successors
// are modified, the method should insert pairs of <OldSucc, NewSucc> into the
// DenseMap.
MachineBasicBlock *TargetLowering::EmitInstrWithCustomInserter(MachineInstr *MI,
MachineBasicBlock *MBB,
DenseMap<MachineBasicBlock*, MachineBasicBlock*> *EM) const {
#ifndef NDEBUG
dbgs() << "If a target marks an instruction with "
"'usesCustomInserter', it must implement "
"TargetLowering::EmitInstrWithCustomInserter!";
#endif
llvm_unreachable(0);
return 0;
}
/// EmitLiveInCopy - Emit a copy for a live in physical register. If the
/// physical register has only a single copy use, then coalesced the copy
/// if possible.
static void EmitLiveInCopy(MachineBasicBlock *MBB,
MachineBasicBlock::iterator &InsertPos,
unsigned VirtReg, unsigned PhysReg,
const TargetRegisterClass *RC,
DenseMap<MachineInstr*, unsigned> &CopyRegMap,
const MachineRegisterInfo &MRI,
const TargetRegisterInfo &TRI,
const TargetInstrInfo &TII) {
unsigned NumUses = 0;
MachineInstr *UseMI = NULL;
for (MachineRegisterInfo::use_iterator UI = MRI.use_begin(VirtReg),
UE = MRI.use_end(); UI != UE; ++UI) {
UseMI = &*UI;
if (++NumUses > 1)
break;
}
// If the number of uses is not one, or the use is not a move instruction,
// don't coalesce. Also, only coalesce away a virtual register to virtual
// register copy.
bool Coalesced = false;
unsigned SrcReg, DstReg, SrcSubReg, DstSubReg;
if (NumUses == 1 &&
TII.isMoveInstr(*UseMI, SrcReg, DstReg, SrcSubReg, DstSubReg) &&
TargetRegisterInfo::isVirtualRegister(DstReg)) {
VirtReg = DstReg;
Coalesced = true;
}
// Now find an ideal location to insert the copy.
MachineBasicBlock::iterator Pos = InsertPos;
while (Pos != MBB->begin()) {
MachineInstr *PrevMI = prior(Pos);
DenseMap<MachineInstr*, unsigned>::iterator RI = CopyRegMap.find(PrevMI);
// copyRegToReg might emit multiple instructions to do a copy.
unsigned CopyDstReg = (RI == CopyRegMap.end()) ? 0 : RI->second;
if (CopyDstReg && !TRI.regsOverlap(CopyDstReg, PhysReg))
// This is what the BB looks like right now:
// r1024 = mov r0
// ...
// r1 = mov r1024
//
// We want to insert "r1025 = mov r1". Inserting this copy below the
// move to r1024 makes it impossible for that move to be coalesced.
//
// r1025 = mov r1
// r1024 = mov r0
// ...
// r1 = mov 1024
// r2 = mov 1025
break; // Woot! Found a good location.
--Pos;
}
bool Emitted = TII.copyRegToReg(*MBB, Pos, VirtReg, PhysReg, RC, RC);
assert(Emitted && "Unable to issue a live-in copy instruction!\n");
(void) Emitted;
CopyRegMap.insert(std::make_pair(prior(Pos), VirtReg));
if (Coalesced) {
if (&*InsertPos == UseMI) ++InsertPos;
MBB->erase(UseMI);
}
}
/// EmitLiveInCopies - If this is the first basic block in the function,
/// and if it has live ins that need to be copied into vregs, emit the
/// copies into the block.
static void EmitLiveInCopies(MachineBasicBlock *EntryMBB,
const MachineRegisterInfo &MRI,
const TargetRegisterInfo &TRI,
const TargetInstrInfo &TII) {
if (SchedLiveInCopies) {
// Emit the copies at a heuristically-determined location in the block.
DenseMap<MachineInstr*, unsigned> CopyRegMap;
MachineBasicBlock::iterator InsertPos = EntryMBB->begin();
for (MachineRegisterInfo::livein_iterator LI = MRI.livein_begin(),
E = MRI.livein_end(); LI != E; ++LI)
if (LI->second) {
const TargetRegisterClass *RC = MRI.getRegClass(LI->second);
EmitLiveInCopy(EntryMBB, InsertPos, LI->second, LI->first,
RC, CopyRegMap, MRI, TRI, TII);
}
} else {
// Emit the copies into the top of the block.
for (MachineRegisterInfo::livein_iterator LI = MRI.livein_begin(),
E = MRI.livein_end(); LI != E; ++LI)
if (LI->second) {
const TargetRegisterClass *RC = MRI.getRegClass(LI->second);
bool Emitted = TII.copyRegToReg(*EntryMBB, EntryMBB->begin(),
LI->second, LI->first, RC, RC);
assert(Emitted && "Unable to issue a live-in copy instruction!\n");
(void) Emitted;
}
}
}
//===----------------------------------------------------------------------===//
// SelectionDAGISel code
//===----------------------------------------------------------------------===//
SelectionDAGISel::SelectionDAGISel(TargetMachine &tm, CodeGenOpt::Level OL) :
MachineFunctionPass(&ID), TM(tm), TLI(*tm.getTargetLowering()),
FuncInfo(new FunctionLoweringInfo(TLI)),
CurDAG(new SelectionDAG(TLI, *FuncInfo)),
SDB(new SelectionDAGBuilder(*CurDAG, TLI, *FuncInfo, OL)),
GFI(),
OptLevel(OL),
DAGSize(0)
{}
SelectionDAGISel::~SelectionDAGISel() {
delete SDB;
delete CurDAG;
delete FuncInfo;
}
unsigned SelectionDAGISel::MakeReg(EVT VT) {
return RegInfo->createVirtualRegister(TLI.getRegClassFor(VT));
}
void SelectionDAGISel::getAnalysisUsage(AnalysisUsage &AU) const {
AU.addRequired<AliasAnalysis>();
AU.addPreserved<AliasAnalysis>();
AU.addRequired<GCModuleInfo>();
AU.addPreserved<GCModuleInfo>();
AU.addRequired<DwarfWriter>();
AU.addPreserved<DwarfWriter>();
MachineFunctionPass::getAnalysisUsage(AU);
}
bool SelectionDAGISel::runOnMachineFunction(MachineFunction &mf) {
Function &Fn = *mf.getFunction();
// Do some sanity-checking on the command-line options.
assert((!EnableFastISelVerbose || EnableFastISel) &&
"-fast-isel-verbose requires -fast-isel");
assert((!EnableFastISelAbort || EnableFastISel) &&
"-fast-isel-abort requires -fast-isel");
// Get alias analysis for load/store combining.
AA = &getAnalysis<AliasAnalysis>();
MF = &mf;
const TargetInstrInfo &TII = *TM.getInstrInfo();
const TargetRegisterInfo &TRI = *TM.getRegisterInfo();
if (Fn.hasGC())
GFI = &getAnalysis<GCModuleInfo>().getFunctionInfo(Fn);
else
GFI = 0;
RegInfo = &MF->getRegInfo();
DEBUG(dbgs() << "\n\n\n=== " << Fn.getName() << "\n");
MachineModuleInfo *MMI = getAnalysisIfAvailable<MachineModuleInfo>();
DwarfWriter *DW = getAnalysisIfAvailable<DwarfWriter>();
CurDAG->init(*MF, MMI, DW);
FuncInfo->set(Fn, *MF, EnableFastISel);
SDB->init(GFI, *AA);
for (Function::iterator I = Fn.begin(), E = Fn.end(); I != E; ++I)
if (InvokeInst *Invoke = dyn_cast<InvokeInst>(I->getTerminator()))
// Mark landing pad.
FuncInfo->MBBMap[Invoke->getSuccessor(1)]->setIsLandingPad();
SelectAllBasicBlocks(Fn, *MF, MMI, DW, TII);
// If the first basic block in the function has live ins that need to be
// copied into vregs, emit the copies into the top of the block before
// emitting the code for the block.
EmitLiveInCopies(MF->begin(), *RegInfo, TRI, TII);
// Add function live-ins to entry block live-in set.
for (MachineRegisterInfo::livein_iterator I = RegInfo->livein_begin(),
E = RegInfo->livein_end(); I != E; ++I)
MF->begin()->addLiveIn(I->first);
#ifndef NDEBUG
assert(FuncInfo->CatchInfoFound.size() == FuncInfo->CatchInfoLost.size() &&
"Not all catch info was assigned to a landing pad!");
#endif
FuncInfo->clear();
return true;
}
/// SetDebugLoc - Update MF's and SDB's DebugLocs if debug information is
/// attached with this instruction.
static void SetDebugLoc(unsigned MDDbgKind, Instruction *I,
SelectionDAGBuilder *SDB,
FastISel *FastIS, MachineFunction *MF) {
if (isa<DbgInfoIntrinsic>(I)) return;
if (MDNode *Dbg = I->getMetadata(MDDbgKind)) {
DILocation DILoc(Dbg);
DebugLoc Loc = ExtractDebugLocation(DILoc, MF->getDebugLocInfo());
SDB->setCurDebugLoc(Loc);
if (FastIS)
FastIS->setCurDebugLoc(Loc);
// If the function doesn't have a default debug location yet, set
// it. This is kind of a hack.
if (MF->getDefaultDebugLoc().isUnknown())
MF->setDefaultDebugLoc(Loc);
}
}
/// ResetDebugLoc - Set MF's and SDB's DebugLocs to Unknown.
static void ResetDebugLoc(SelectionDAGBuilder *SDB, FastISel *FastIS) {
SDB->setCurDebugLoc(DebugLoc::getUnknownLoc());
if (FastIS)
FastIS->setCurDebugLoc(DebugLoc::getUnknownLoc());
}
void SelectionDAGISel::SelectBasicBlock(BasicBlock *LLVMBB,
BasicBlock::iterator Begin,
BasicBlock::iterator End,
bool &HadTailCall) {
SDB->setCurrentBasicBlock(BB);
unsigned MDDbgKind = LLVMBB->getContext().getMDKindID("dbg");
// Lower all of the non-terminator instructions. If a call is emitted
// as a tail call, cease emitting nodes for this block.
for (BasicBlock::iterator I = Begin; I != End && !SDB->HasTailCall; ++I) {
SetDebugLoc(MDDbgKind, I, SDB, 0, MF);
if (!isa<TerminatorInst>(I)) {
SDB->visit(*I);
// Set the current debug location back to "unknown" so that it doesn't
// spuriously apply to subsequent instructions.
ResetDebugLoc(SDB, 0);
}
}
if (!SDB->HasTailCall) {
// Ensure that all instructions which are used outside of their defining
// blocks are available as virtual registers. Invoke is handled elsewhere.
for (BasicBlock::iterator I = Begin; I != End; ++I)
if (!isa<PHINode>(I) && !isa<InvokeInst>(I))
SDB->CopyToExportRegsIfNeeded(I);
// Handle PHI nodes in successor blocks.
if (End == LLVMBB->end()) {
HandlePHINodesInSuccessorBlocks(LLVMBB);
// Lower the terminator after the copies are emitted.
SetDebugLoc(MDDbgKind, LLVMBB->getTerminator(), SDB, 0, MF);
SDB->visit(*LLVMBB->getTerminator());
ResetDebugLoc(SDB, 0);
}
}
// Make sure the root of the DAG is up-to-date.
CurDAG->setRoot(SDB->getControlRoot());
// Final step, emit the lowered DAG as machine code.
CodeGenAndEmitDAG();
HadTailCall = SDB->HasTailCall;
SDB->clear();
}
namespace {
/// WorkListRemover - This class is a DAGUpdateListener that removes any deleted
/// nodes from the worklist.
class SDOPsWorkListRemover : public SelectionDAG::DAGUpdateListener {
SmallVector<SDNode*, 128> &Worklist;
public:
SDOPsWorkListRemover(SmallVector<SDNode*, 128> &wl) : Worklist(wl) {}
virtual void NodeDeleted(SDNode *N, SDNode *E) {
Worklist.erase(std::remove(Worklist.begin(), Worklist.end(), N),
Worklist.end());
}
virtual void NodeUpdated(SDNode *N) {
// Ignore updates.
}
};
}
/// TrivialTruncElim - Eliminate some trivial nops that can result from
/// ShrinkDemandedOps: (trunc (ext n)) -> n.
static bool TrivialTruncElim(SDValue Op,
TargetLowering::TargetLoweringOpt &TLO) {
SDValue N0 = Op.getOperand(0);
EVT VT = Op.getValueType();
if ((N0.getOpcode() == ISD::ZERO_EXTEND ||
N0.getOpcode() == ISD::SIGN_EXTEND ||
N0.getOpcode() == ISD::ANY_EXTEND) &&
N0.getOperand(0).getValueType() == VT) {
return TLO.CombineTo(Op, N0.getOperand(0));
}
return false;
}
/// ShrinkDemandedOps - A late transformation pass that shrink expressions
/// using TargetLowering::TargetLoweringOpt::ShrinkDemandedOp. It converts
/// x+y to (VT)((SmallVT)x+(SmallVT)y) if the casts are free.
void SelectionDAGISel::ShrinkDemandedOps() {
SmallVector<SDNode*, 128> Worklist;
// Add all the dag nodes to the worklist.
Worklist.reserve(CurDAG->allnodes_size());
for (SelectionDAG::allnodes_iterator I = CurDAG->allnodes_begin(),
E = CurDAG->allnodes_end(); I != E; ++I)
Worklist.push_back(I);
APInt Mask;
APInt KnownZero;
APInt KnownOne;
TargetLowering::TargetLoweringOpt TLO(*CurDAG, true);
while (!Worklist.empty()) {
SDNode *N = Worklist.pop_back_val();
if (N->use_empty() && N != CurDAG->getRoot().getNode()) {
CurDAG->DeleteNode(N);
continue;
}
// Run ShrinkDemandedOp on scalar binary operations.
if (N->getNumValues() == 1 &&
N->getValueType(0).isSimple() && N->getValueType(0).isInteger()) {
unsigned BitWidth = N->getValueType(0).getScalarType().getSizeInBits();
APInt Demanded = APInt::getAllOnesValue(BitWidth);
APInt KnownZero, KnownOne;
if (TLI.SimplifyDemandedBits(SDValue(N, 0), Demanded,
KnownZero, KnownOne, TLO) ||
(N->getOpcode() == ISD::TRUNCATE &&
TrivialTruncElim(SDValue(N, 0), TLO))) {
// Revisit the node.
Worklist.erase(std::remove(Worklist.begin(), Worklist.end(), N),
Worklist.end());
Worklist.push_back(N);
// Replace the old value with the new one.
DEBUG(errs() << "\nReplacing ";
TLO.Old.getNode()->dump(CurDAG);
errs() << "\nWith: ";
TLO.New.getNode()->dump(CurDAG);
errs() << '\n');
Worklist.push_back(TLO.New.getNode());
SDOPsWorkListRemover DeadNodes(Worklist);
CurDAG->ReplaceAllUsesOfValueWith(TLO.Old, TLO.New, &DeadNodes);
if (TLO.Old.getNode()->use_empty()) {
for (unsigned i = 0, e = TLO.Old.getNode()->getNumOperands();
i != e; ++i) {
SDNode *OpNode = TLO.Old.getNode()->getOperand(i).getNode();
if (OpNode->hasOneUse()) {
Worklist.erase(std::remove(Worklist.begin(), Worklist.end(),
OpNode), Worklist.end());
Worklist.push_back(OpNode);
}
}
Worklist.erase(std::remove(Worklist.begin(), Worklist.end(),
TLO.Old.getNode()), Worklist.end());
CurDAG->DeleteNode(TLO.Old.getNode());
}
}
}
}
}
void SelectionDAGISel::ComputeLiveOutVRegInfo() {
SmallPtrSet<SDNode*, 128> VisitedNodes;
SmallVector<SDNode*, 128> Worklist;
Worklist.push_back(CurDAG->getRoot().getNode());
APInt Mask;
APInt KnownZero;
APInt KnownOne;
do {
SDNode *N = Worklist.pop_back_val();
// If we've already seen this node, ignore it.
if (!VisitedNodes.insert(N))
continue;
// Otherwise, add all chain operands to the worklist.
for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
if (N->getOperand(i).getValueType() == MVT::Other)
Worklist.push_back(N->getOperand(i).getNode());
// If this is a CopyToReg with a vreg dest, process it.
if (N->getOpcode() != ISD::CopyToReg)
continue;
unsigned DestReg = cast<RegisterSDNode>(N->getOperand(1))->getReg();
if (!TargetRegisterInfo::isVirtualRegister(DestReg))
continue;
// Ignore non-scalar or non-integer values.
SDValue Src = N->getOperand(2);
EVT SrcVT = Src.getValueType();
if (!SrcVT.isInteger() || SrcVT.isVector())
continue;
unsigned NumSignBits = CurDAG->ComputeNumSignBits(Src);
Mask = APInt::getAllOnesValue(SrcVT.getSizeInBits());
CurDAG->ComputeMaskedBits(Src, Mask, KnownZero, KnownOne);
// Only install this information if it tells us something.
if (NumSignBits != 1 || KnownZero != 0 || KnownOne != 0) {
DestReg -= TargetRegisterInfo::FirstVirtualRegister;
if (DestReg >= FuncInfo->LiveOutRegInfo.size())
FuncInfo->LiveOutRegInfo.resize(DestReg+1);
FunctionLoweringInfo::LiveOutInfo &LOI =
FuncInfo->LiveOutRegInfo[DestReg];
LOI.NumSignBits = NumSignBits;
LOI.KnownOne = KnownOne;
LOI.KnownZero = KnownZero;
}
} while (!Worklist.empty());
}
void SelectionDAGISel::CodeGenAndEmitDAG() {
std::string GroupName;
if (TimePassesIsEnabled)
GroupName = "Instruction Selection and Scheduling";
std::string BlockName;
if (ViewDAGCombine1 || ViewLegalizeTypesDAGs || ViewLegalizeDAGs ||
ViewDAGCombine2 || ViewDAGCombineLT || ViewISelDAGs || ViewSchedDAGs ||
ViewSUnitDAGs)
BlockName = MF->getFunction()->getNameStr() + ":" +
BB->getBasicBlock()->getNameStr();
DEBUG(dbgs() << "Initial selection DAG:\n");
DEBUG(CurDAG->dump());
if (ViewDAGCombine1) CurDAG->viewGraph("dag-combine1 input for " + BlockName);
// Run the DAG combiner in pre-legalize mode.
if (TimePassesIsEnabled) {
NamedRegionTimer T("DAG Combining 1", GroupName);
CurDAG->Combine(Unrestricted, *AA, OptLevel);
} else {
CurDAG->Combine(Unrestricted, *AA, OptLevel);
}
DEBUG(dbgs() << "Optimized lowered selection DAG:\n");
DEBUG(CurDAG->dump());
// Second step, hack on the DAG until it only uses operations and types that
// the target supports.
if (ViewLegalizeTypesDAGs) CurDAG->viewGraph("legalize-types input for " +
BlockName);
bool Changed;
if (TimePassesIsEnabled) {
NamedRegionTimer T("Type Legalization", GroupName);
Changed = CurDAG->LegalizeTypes();
} else {
Changed = CurDAG->LegalizeTypes();
}
DEBUG(dbgs() << "Type-legalized selection DAG:\n");
DEBUG(CurDAG->dump());
if (Changed) {
if (ViewDAGCombineLT)
CurDAG->viewGraph("dag-combine-lt input for " + BlockName);
// Run the DAG combiner in post-type-legalize mode.
if (TimePassesIsEnabled) {
NamedRegionTimer T("DAG Combining after legalize types", GroupName);
CurDAG->Combine(NoIllegalTypes, *AA, OptLevel);
} else {
CurDAG->Combine(NoIllegalTypes, *AA, OptLevel);
}
DEBUG(dbgs() << "Optimized type-legalized selection DAG:\n");
DEBUG(CurDAG->dump());
}
if (TimePassesIsEnabled) {
NamedRegionTimer T("Vector Legalization", GroupName);
Changed = CurDAG->LegalizeVectors();
} else {
Changed = CurDAG->LegalizeVectors();
}
if (Changed) {
if (TimePassesIsEnabled) {
NamedRegionTimer T("Type Legalization 2", GroupName);
CurDAG->LegalizeTypes();
} else {
CurDAG->LegalizeTypes();
}
if (ViewDAGCombineLT)
CurDAG->viewGraph("dag-combine-lv input for " + BlockName);
// Run the DAG combiner in post-type-legalize mode.
if (TimePassesIsEnabled) {
NamedRegionTimer T("DAG Combining after legalize vectors", GroupName);
CurDAG->Combine(NoIllegalOperations, *AA, OptLevel);
} else {
CurDAG->Combine(NoIllegalOperations, *AA, OptLevel);
}
DEBUG(dbgs() << "Optimized vector-legalized selection DAG:\n");
DEBUG(CurDAG->dump());
}
if (ViewLegalizeDAGs) CurDAG->viewGraph("legalize input for " + BlockName);
if (TimePassesIsEnabled) {
NamedRegionTimer T("DAG Legalization", GroupName);
CurDAG->Legalize(OptLevel);
} else {
CurDAG->Legalize(OptLevel);
}
DEBUG(dbgs() << "Legalized selection DAG:\n");
DEBUG(CurDAG->dump());
if (ViewDAGCombine2) CurDAG->viewGraph("dag-combine2 input for " + BlockName);
// Run the DAG combiner in post-legalize mode.
if (TimePassesIsEnabled) {
NamedRegionTimer T("DAG Combining 2", GroupName);
CurDAG->Combine(NoIllegalOperations, *AA, OptLevel);
} else {
CurDAG->Combine(NoIllegalOperations, *AA, OptLevel);
}
DEBUG(dbgs() << "Optimized legalized selection DAG:\n");
DEBUG(CurDAG->dump());
if (ViewISelDAGs) CurDAG->viewGraph("isel input for " + BlockName);
if (OptLevel != CodeGenOpt::None) {
ShrinkDemandedOps();
ComputeLiveOutVRegInfo();
}
// Third, instruction select all of the operations to machine code, adding the
// code to the MachineBasicBlock.
if (TimePassesIsEnabled) {
NamedRegionTimer T("Instruction Selection", GroupName);
InstructionSelect();
} else {
InstructionSelect();
}
DEBUG(dbgs() << "Selected selection DAG:\n");
DEBUG(CurDAG->dump());
if (ViewSchedDAGs) CurDAG->viewGraph("scheduler input for " + BlockName);
// Schedule machine code.
ScheduleDAGSDNodes *Scheduler = CreateScheduler();
if (TimePassesIsEnabled) {
NamedRegionTimer T("Instruction Scheduling", GroupName);
Scheduler->Run(CurDAG, BB, BB->end());
} else {
Scheduler->Run(CurDAG, BB, BB->end());
}
if (ViewSUnitDAGs) Scheduler->viewGraph();
// Emit machine code to BB. This can change 'BB' to the last block being
// inserted into.
if (TimePassesIsEnabled) {
NamedRegionTimer T("Instruction Creation", GroupName);
BB = Scheduler->EmitSchedule(&SDB->EdgeMapping);
} else {
BB = Scheduler->EmitSchedule(&SDB->EdgeMapping);
}
// Free the scheduler state.
if (TimePassesIsEnabled) {
NamedRegionTimer T("Instruction Scheduling Cleanup", GroupName);
delete Scheduler;
} else {
delete Scheduler;
}
DEBUG(dbgs() << "Selected machine code:\n");
DEBUG(BB->dump());
}
void SelectionDAGISel::SelectAllBasicBlocks(Function &Fn,
MachineFunction &MF,
MachineModuleInfo *MMI,
DwarfWriter *DW,
const TargetInstrInfo &TII) {
// Initialize the Fast-ISel state, if needed.
FastISel *FastIS = 0;
if (EnableFastISel)
FastIS = TLI.createFastISel(MF, MMI, DW,
FuncInfo->ValueMap,
FuncInfo->MBBMap,
FuncInfo->StaticAllocaMap
#ifndef NDEBUG
, FuncInfo->CatchInfoLost
#endif
);
unsigned MDDbgKind = Fn.getContext().getMDKindID("dbg");
// Iterate over all basic blocks in the function.
for (Function::iterator I = Fn.begin(), E = Fn.end(); I != E; ++I) {
BasicBlock *LLVMBB = &*I;
BB = FuncInfo->MBBMap[LLVMBB];
BasicBlock::iterator const Begin = LLVMBB->begin();
BasicBlock::iterator const End = LLVMBB->end();
BasicBlock::iterator BI = Begin;
// Lower any arguments needed in this block if this is the entry block.
bool SuppressFastISel = false;
if (LLVMBB == &Fn.getEntryBlock()) {
LowerArguments(LLVMBB);
// If any of the arguments has the byval attribute, forgo
// fast-isel in the entry block.
if (FastIS) {
unsigned j = 1;
for (Function::arg_iterator I = Fn.arg_begin(), E = Fn.arg_end();
I != E; ++I, ++j)
if (Fn.paramHasAttr(j, Attribute::ByVal)) {
if (EnableFastISelVerbose || EnableFastISelAbort)
dbgs() << "FastISel skips entry block due to byval argument\n";
SuppressFastISel = true;
break;
}
}
}
if (MMI && BB->isLandingPad()) {
// Add a label to mark the beginning of the landing pad. Deletion of the
// landing pad can thus be detected via the MachineModuleInfo.
unsigned LabelID = MMI->addLandingPad(BB);
const TargetInstrDesc &II = TII.get(TargetOpcode::EH_LABEL);
BuildMI(BB, SDB->getCurDebugLoc(), II).addImm(LabelID);
// Mark exception register as live in.
unsigned Reg = TLI.getExceptionAddressRegister();
if (Reg) BB->addLiveIn(Reg);
// Mark exception selector register as live in.
Reg = TLI.getExceptionSelectorRegister();
if (Reg) BB->addLiveIn(Reg);
// FIXME: Hack around an exception handling flaw (PR1508): the personality
// function and list of typeids logically belong to the invoke (or, if you
// like, the basic block containing the invoke), and need to be associated
// with it in the dwarf exception handling tables. Currently however the
// information is provided by an intrinsic (eh.selector) that can be moved
// to unexpected places by the optimizers: if the unwind edge is critical,
// then breaking it can result in the intrinsics being in the successor of
// the landing pad, not the landing pad itself. This results
// in exceptions not being caught because no typeids are associated with
// the invoke. This may not be the only way things can go wrong, but it
// is the only way we try to work around for the moment.
BranchInst *Br = dyn_cast<BranchInst>(LLVMBB->getTerminator());
if (Br && Br->isUnconditional()) { // Critical edge?
BasicBlock::iterator I, E;
for (I = LLVMBB->begin(), E = --LLVMBB->end(); I != E; ++I)
if (isa<EHSelectorInst>(I))
break;
if (I == E)
// No catch info found - try to extract some from the successor.
CopyCatchInfo(Br->getSuccessor(0), LLVMBB, MMI, *FuncInfo);
}
}
// Before doing SelectionDAG ISel, see if FastISel has been requested.
if (FastIS && !SuppressFastISel) {
// Emit code for any incoming arguments. This must happen before
// beginning FastISel on the entry block.
if (LLVMBB == &Fn.getEntryBlock()) {
CurDAG->setRoot(SDB->getControlRoot());
CodeGenAndEmitDAG();
SDB->clear();
}
FastIS->startNewBlock(BB);
// Do FastISel on as many instructions as possible.
for (; BI != End; ++BI) {
// Just before the terminator instruction, insert instructions to
// feed PHI nodes in successor blocks.
if (isa<TerminatorInst>(BI))
if (!HandlePHINodesInSuccessorBlocksFast(LLVMBB, FastIS)) {
ResetDebugLoc(SDB, FastIS);
if (EnableFastISelVerbose || EnableFastISelAbort) {
dbgs() << "FastISel miss: ";
BI->dump();
}
assert(!EnableFastISelAbort &&
"FastISel didn't handle a PHI in a successor");
break;
}
SetDebugLoc(MDDbgKind, BI, SDB, FastIS, &MF);
// Try to select the instruction with FastISel.
if (FastIS->SelectInstruction(BI)) {
ResetDebugLoc(SDB, FastIS);
continue;
}
// Clear out the debug location so that it doesn't carry over to
// unrelated instructions.
ResetDebugLoc(SDB, FastIS);
// Then handle certain instructions as single-LLVM-Instruction blocks.
if (isa<CallInst>(BI)) {
if (EnableFastISelVerbose || EnableFastISelAbort) {
dbgs() << "FastISel missed call: ";
BI->dump();
}
if (!BI->getType()->isVoidTy()) {
unsigned &R = FuncInfo->ValueMap[BI];
if (!R)
R = FuncInfo->CreateRegForValue(BI);
}
bool HadTailCall = false;
SelectBasicBlock(LLVMBB, BI, llvm::next(BI), HadTailCall);
// If the call was emitted as a tail call, we're done with the block.
if (HadTailCall) {
BI = End;
break;
}
// If the instruction was codegen'd with multiple blocks,
// inform the FastISel object where to resume inserting.
FastIS->setCurrentBlock(BB);
continue;
}
// Otherwise, give up on FastISel for the rest of the block.
// For now, be a little lenient about non-branch terminators.
if (!isa<TerminatorInst>(BI) || isa<BranchInst>(BI)) {
if (EnableFastISelVerbose || EnableFastISelAbort) {
dbgs() << "FastISel miss: ";
BI->dump();
}
if (EnableFastISelAbort)
// The "fast" selector couldn't handle something and bailed.
// For the purpose of debugging, just abort.
llvm_unreachable("FastISel didn't select the entire block");
}
break;
}
}
// Run SelectionDAG instruction selection on the remainder of the block
// not handled by FastISel. If FastISel is not run, this is the entire
// block.
if (BI != End) {
bool HadTailCall;
SelectBasicBlock(LLVMBB, BI, End, HadTailCall);
}
FinishBasicBlock();
}
delete FastIS;
}
void
SelectionDAGISel::FinishBasicBlock() {
DEBUG(dbgs() << "Target-post-processed machine code:\n");
DEBUG(BB->dump());
DEBUG(dbgs() << "Total amount of phi nodes to update: "
<< SDB->PHINodesToUpdate.size() << "\n");
DEBUG(for (unsigned i = 0, e = SDB->PHINodesToUpdate.size(); i != e; ++i)
dbgs() << "Node " << i << " : ("
<< SDB->PHINodesToUpdate[i].first
<< ", " << SDB->PHINodesToUpdate[i].second << ")\n");
// Next, now that we know what the last MBB the LLVM BB expanded is, update
// PHI nodes in successors.
if (SDB->SwitchCases.empty() &&
SDB->JTCases.empty() &&
SDB->BitTestCases.empty()) {
for (unsigned i = 0, e = SDB->PHINodesToUpdate.size(); i != e; ++i) {
MachineInstr *PHI = SDB->PHINodesToUpdate[i].first;
assert(PHI->isPHI() &&
"This is not a machine PHI node that we are updating!");
PHI->addOperand(MachineOperand::CreateReg(SDB->PHINodesToUpdate[i].second,
false));
PHI->addOperand(MachineOperand::CreateMBB(BB));
}
SDB->PHINodesToUpdate.clear();
return;
}
for (unsigned i = 0, e = SDB->BitTestCases.size(); i != e; ++i) {
// Lower header first, if it wasn't already lowered
if (!SDB->BitTestCases[i].Emitted) {
// Set the current basic block to the mbb we wish to insert the code into
BB = SDB->BitTestCases[i].Parent;
SDB->setCurrentBasicBlock(BB);
// Emit the code
SDB->visitBitTestHeader(SDB->BitTestCases[i]);
CurDAG->setRoot(SDB->getRoot());
CodeGenAndEmitDAG();
SDB->clear();
}
for (unsigned j = 0, ej = SDB->BitTestCases[i].Cases.size(); j != ej; ++j) {
// Set the current basic block to the mbb we wish to insert the code into
BB = SDB->BitTestCases[i].Cases[j].ThisBB;
SDB->setCurrentBasicBlock(BB);
// Emit the code
if (j+1 != ej)
SDB->visitBitTestCase(SDB->BitTestCases[i].Cases[j+1].ThisBB,
SDB->BitTestCases[i].Reg,
SDB->BitTestCases[i].Cases[j]);
else
SDB->visitBitTestCase(SDB->BitTestCases[i].Default,
SDB->BitTestCases[i].Reg,
SDB->BitTestCases[i].Cases[j]);
CurDAG->setRoot(SDB->getRoot());
CodeGenAndEmitDAG();
SDB->clear();
}
// Update PHI Nodes
for (unsigned pi = 0, pe = SDB->PHINodesToUpdate.size(); pi != pe; ++pi) {
MachineInstr *PHI = SDB->PHINodesToUpdate[pi].first;
MachineBasicBlock *PHIBB = PHI->getParent();
assert(PHI->isPHI() &&
"This is not a machine PHI node that we are updating!");
// This is "default" BB. We have two jumps to it. From "header" BB and
// from last "case" BB.
if (PHIBB == SDB->BitTestCases[i].Default) {
PHI->addOperand(MachineOperand::
CreateReg(SDB->PHINodesToUpdate[pi].second, false));
PHI->addOperand(MachineOperand::CreateMBB(SDB->BitTestCases[i].Parent));
PHI->addOperand(MachineOperand::
CreateReg(SDB->PHINodesToUpdate[pi].second, false));
PHI->addOperand(MachineOperand::CreateMBB(SDB->BitTestCases[i].Cases.
back().ThisBB));
}
// One of "cases" BB.
for (unsigned j = 0, ej = SDB->BitTestCases[i].Cases.size();
j != ej; ++j) {
MachineBasicBlock* cBB = SDB->BitTestCases[i].Cases[j].ThisBB;
if (cBB->isSuccessor(PHIBB)) {
PHI->addOperand(MachineOperand::
CreateReg(SDB->PHINodesToUpdate[pi].second, false));
PHI->addOperand(MachineOperand::CreateMBB(cBB));
}
}
}
}
SDB->BitTestCases.clear();
// If the JumpTable record is filled in, then we need to emit a jump table.
// Updating the PHI nodes is tricky in this case, since we need to determine
// whether the PHI is a successor of the range check MBB or the jump table MBB
for (unsigned i = 0, e = SDB->JTCases.size(); i != e; ++i) {
// Lower header first, if it wasn't already lowered
if (!SDB->JTCases[i].first.Emitted) {
// Set the current basic block to the mbb we wish to insert the code into
BB = SDB->JTCases[i].first.HeaderBB;
SDB->setCurrentBasicBlock(BB);
// Emit the code
SDB->visitJumpTableHeader(SDB->JTCases[i].second, SDB->JTCases[i].first);
CurDAG->setRoot(SDB->getRoot());
CodeGenAndEmitDAG();
SDB->clear();
}
// Set the current basic block to the mbb we wish to insert the code into
BB = SDB->JTCases[i].second.MBB;
SDB->setCurrentBasicBlock(BB);
// Emit the code
SDB->visitJumpTable(SDB->JTCases[i].second);
CurDAG->setRoot(SDB->getRoot());
CodeGenAndEmitDAG();
SDB->clear();
// Update PHI Nodes
for (unsigned pi = 0, pe = SDB->PHINodesToUpdate.size(); pi != pe; ++pi) {
MachineInstr *PHI = SDB->PHINodesToUpdate[pi].first;
MachineBasicBlock *PHIBB = PHI->getParent();
assert(PHI->isPHI() &&
"This is not a machine PHI node that we are updating!");
// "default" BB. We can go there only from header BB.
if (PHIBB == SDB->JTCases[i].second.Default) {
PHI->addOperand
(MachineOperand::CreateReg(SDB->PHINodesToUpdate[pi].second, false));
PHI->addOperand
(MachineOperand::CreateMBB(SDB->JTCases[i].first.HeaderBB));
}
// JT BB. Just iterate over successors here
if (BB->isSuccessor(PHIBB)) {
PHI->addOperand
(MachineOperand::CreateReg(SDB->PHINodesToUpdate[pi].second, false));
PHI->addOperand(MachineOperand::CreateMBB(BB));
}
}
}
SDB->JTCases.clear();
// If the switch block involved a branch to one of the actual successors, we
// need to update PHI nodes in that block.
for (unsigned i = 0, e = SDB->PHINodesToUpdate.size(); i != e; ++i) {
MachineInstr *PHI = SDB->PHINodesToUpdate[i].first;
assert(PHI->isPHI() &&
"This is not a machine PHI node that we are updating!");
if (BB->isSuccessor(PHI->getParent())) {
PHI->addOperand(MachineOperand::CreateReg(SDB->PHINodesToUpdate[i].second,
false));
PHI->addOperand(MachineOperand::CreateMBB(BB));
}
}
// If we generated any switch lowering information, build and codegen any
// additional DAGs necessary.
for (unsigned i = 0, e = SDB->SwitchCases.size(); i != e; ++i) {
// Set the current basic block to the mbb we wish to insert the code into
MachineBasicBlock *ThisBB = BB = SDB->SwitchCases[i].ThisBB;
SDB->setCurrentBasicBlock(BB);
// Emit the code
SDB->visitSwitchCase(SDB->SwitchCases[i]);
CurDAG->setRoot(SDB->getRoot());
CodeGenAndEmitDAG();
// Handle any PHI nodes in successors of this chunk, as if we were coming
// from the original BB before switch expansion. Note that PHI nodes can
// occur multiple times in PHINodesToUpdate. We have to be very careful to
// handle them the right number of times.
while ((BB = SDB->SwitchCases[i].TrueBB)) { // Handle LHS and RHS.
// If new BB's are created during scheduling, the edges may have been
// updated. That is, the edge from ThisBB to BB may have been split and
// BB's predecessor is now another block.
DenseMap<MachineBasicBlock*, MachineBasicBlock*>::iterator EI =
SDB->EdgeMapping.find(BB);
if (EI != SDB->EdgeMapping.end())
ThisBB = EI->second;
// BB may have been removed from the CFG if a branch was constant folded.
if (ThisBB->isSuccessor(BB)) {
for (MachineBasicBlock::iterator Phi = BB->begin();
Phi != BB->end() && Phi->isPHI();
++Phi) {
// This value for this PHI node is recorded in PHINodesToUpdate.
for (unsigned pn = 0; ; ++pn) {
assert(pn != SDB->PHINodesToUpdate.size() &&
"Didn't find PHI entry!");
if (SDB->PHINodesToUpdate[pn].first == Phi) {
Phi->addOperand(MachineOperand::
CreateReg(SDB->PHINodesToUpdate[pn].second,
false));
Phi->addOperand(MachineOperand::CreateMBB(ThisBB));
break;
}
}
}
}
// Don't process RHS if same block as LHS.
if (BB == SDB->SwitchCases[i].FalseBB)
SDB->SwitchCases[i].FalseBB = 0;
// If we haven't handled the RHS, do so now. Otherwise, we're done.
SDB->SwitchCases[i].TrueBB = SDB->SwitchCases[i].FalseBB;
SDB->SwitchCases[i].FalseBB = 0;
}
assert(SDB->SwitchCases[i].TrueBB == 0 && SDB->SwitchCases[i].FalseBB == 0);
SDB->clear();
}
SDB->SwitchCases.clear();
SDB->PHINodesToUpdate.clear();
}
/// Create the scheduler. If a specific scheduler was specified
/// via the SchedulerRegistry, use it, otherwise select the
/// one preferred by the target.
///
ScheduleDAGSDNodes *SelectionDAGISel::CreateScheduler() {
RegisterScheduler::FunctionPassCtor Ctor = RegisterScheduler::getDefault();
if (!Ctor) {
Ctor = ISHeuristic;
RegisterScheduler::setDefault(Ctor);
}
return Ctor(this, OptLevel);
}
ScheduleHazardRecognizer *SelectionDAGISel::CreateTargetHazardRecognizer() {
return new ScheduleHazardRecognizer();
}
//===----------------------------------------------------------------------===//
// Helper functions used by the generated instruction selector.
//===----------------------------------------------------------------------===//
// Calls to these methods are generated by tblgen.
/// CheckAndMask - The isel is trying to match something like (and X, 255). If
/// the dag combiner simplified the 255, we still want to match. RHS is the
/// actual value in the DAG on the RHS of an AND, and DesiredMaskS is the value
/// specified in the .td file (e.g. 255).
bool SelectionDAGISel::CheckAndMask(SDValue LHS, ConstantSDNode *RHS,
int64_t DesiredMaskS) const {
const APInt &ActualMask = RHS->getAPIntValue();
const APInt &DesiredMask = APInt(LHS.getValueSizeInBits(), DesiredMaskS);
// If the actual mask exactly matches, success!
if (ActualMask == DesiredMask)
return true;
// If the actual AND mask is allowing unallowed bits, this doesn't match.
if (ActualMask.intersects(~DesiredMask))
return false;
// Otherwise, the DAG Combiner may have proven that the value coming in is
// either already zero or is not demanded. Check for known zero input bits.
APInt NeededMask = DesiredMask & ~ActualMask;
if (CurDAG->MaskedValueIsZero(LHS, NeededMask))
return true;
// TODO: check to see if missing bits are just not demanded.
// Otherwise, this pattern doesn't match.
return false;
}
/// CheckOrMask - The isel is trying to match something like (or X, 255). If
/// the dag combiner simplified the 255, we still want to match. RHS is the
/// actual value in the DAG on the RHS of an OR, and DesiredMaskS is the value
/// specified in the .td file (e.g. 255).
bool SelectionDAGISel::CheckOrMask(SDValue LHS, ConstantSDNode *RHS,
int64_t DesiredMaskS) const {
const APInt &ActualMask = RHS->getAPIntValue();
const APInt &DesiredMask = APInt(LHS.getValueSizeInBits(), DesiredMaskS);
// If the actual mask exactly matches, success!
if (ActualMask == DesiredMask)
return true;
// If the actual AND mask is allowing unallowed bits, this doesn't match.
if (ActualMask.intersects(~DesiredMask))
return false;
// Otherwise, the DAG Combiner may have proven that the value coming in is
// either already zero or is not demanded. Check for known zero input bits.
APInt NeededMask = DesiredMask & ~ActualMask;
APInt KnownZero, KnownOne;
CurDAG->ComputeMaskedBits(LHS, NeededMask, KnownZero, KnownOne);
// If all the missing bits in the or are already known to be set, match!
if ((NeededMask & KnownOne) == NeededMask)
return true;
// TODO: check to see if missing bits are just not demanded.
// Otherwise, this pattern doesn't match.
return false;
}
/// SelectInlineAsmMemoryOperands - Calls to this are automatically generated
/// by tblgen. Others should not call it.
void SelectionDAGISel::
SelectInlineAsmMemoryOperands(std::vector<SDValue> &Ops) {
std::vector<SDValue> InOps;
std::swap(InOps, Ops);
Ops.push_back(InOps[0]); // input chain.
Ops.push_back(InOps[1]); // input asm string.
unsigned i = 2, e = InOps.size();
if (InOps[e-1].getValueType() == MVT::Flag)
--e; // Don't process a flag operand if it is here.
while (i != e) {
unsigned Flags = cast<ConstantSDNode>(InOps[i])->getZExtValue();
if ((Flags & 7) != 4 /*MEM*/) {
// Just skip over this operand, copying the operands verbatim.
Ops.insert(Ops.end(), InOps.begin()+i,
InOps.begin()+i+InlineAsm::getNumOperandRegisters(Flags) + 1);
i += InlineAsm::getNumOperandRegisters(Flags) + 1;
} else {
assert(InlineAsm::getNumOperandRegisters(Flags) == 1 &&
"Memory operand with multiple values?");
// Otherwise, this is a memory operand. Ask the target to select it.
std::vector<SDValue> SelOps;
if (SelectInlineAsmMemoryOperand(InOps[i+1], 'm', SelOps)) {
llvm_report_error("Could not match memory address. Inline asm"
" failure!");
}
// Add this to the output node.
Ops.push_back(CurDAG->getTargetConstant(4/*MEM*/ | (SelOps.size()<< 3),
MVT::i32));
Ops.insert(Ops.end(), SelOps.begin(), SelOps.end());
i += 2;
}
}
// Add the flag input back if present.
if (e != InOps.size())
Ops.push_back(InOps.back());
}
/// findFlagUse - Return use of EVT::Flag value produced by the specified
/// SDNode.
///
static SDNode *findFlagUse(SDNode *N) {
unsigned FlagResNo = N->getNumValues()-1;
for (SDNode::use_iterator I = N->use_begin(), E = N->use_end(); I != E; ++I) {
SDUse &Use = I.getUse();
if (Use.getResNo() == FlagResNo)
return Use.getUser();
}
return NULL;
}
/// findNonImmUse - Return true if "Use" is a non-immediate use of "Def".
/// This function recursively traverses up the operand chain, ignoring
/// certain nodes.
static bool findNonImmUse(SDNode *Use, SDNode* Def, SDNode *ImmedUse,
SDNode *Root,
SmallPtrSet<SDNode*, 16> &Visited) {
// The NodeID's are given uniques ID's where a node ID is guaranteed to be
// greater than all of its (recursive) operands. If we scan to a point where
// 'use' is smaller than the node we're scanning for, then we know we will
// never find it.
//
// The Use may be -1 (unassigned) if it is a newly allocated node. This can
// happen because we scan down to newly selected nodes in the case of flag
// uses.
if ((Use->getNodeId() < Def->getNodeId() && Use->getNodeId() != -1))
return false;
// Don't revisit nodes if we already scanned it and didn't fail, we know we
// won't fail if we scan it again.
if (!Visited.insert(Use))
return false;
for (unsigned i = 0, e = Use->getNumOperands(); i != e; ++i) {
SDNode *N = Use->getOperand(i).getNode();
if (N == Def) {
if (Use == ImmedUse || Use == Root)
continue; // We are not looking for immediate use.
assert(N != Root);
return true;
}
// Traverse up the operand chain.
if (findNonImmUse(N, Def, ImmedUse, Root, Visited))
return true;
}
return false;
}
/// isNonImmUse - Start searching from Root up the DAG to check is Def can
/// be reached. Return true if that's the case. However, ignore direct uses
/// by ImmedUse (which would be U in the example illustrated in
/// IsLegalToFold) and by Root (which can happen in the store case).
/// FIXME: to be really generic, we should allow direct use by any node
/// that is being folded. But realisticly since we only fold loads which
/// have one non-chain use, we only need to watch out for load/op/store
/// and load/op/cmp case where the root (store / cmp) may reach the load via
/// its chain operand.
static inline bool isNonImmUse(SDNode *Root, SDNode *Def, SDNode *ImmedUse) {
SmallPtrSet<SDNode*, 16> Visited;
return findNonImmUse(Root, Def, ImmedUse, Root, Visited);
}
/// IsProfitableToFold - Returns true if it's profitable to fold the specific
/// operand node N of U during instruction selection that starts at Root.
bool SelectionDAGISel::IsProfitableToFold(SDValue N, SDNode *U,
SDNode *Root) const {
if (OptLevel == CodeGenOpt::None) return false;
return N.hasOneUse();
}
/// IsLegalToFold - Returns true if the specific operand node N of
/// U can be folded during instruction selection that starts at Root.
bool SelectionDAGISel::IsLegalToFold(SDValue N, SDNode *U, SDNode *Root) const {
if (OptLevel == CodeGenOpt::None) return false;
// If Root use can somehow reach N through a path that that doesn't contain
// U then folding N would create a cycle. e.g. In the following
// diagram, Root can reach N through X. If N is folded into into Root, then
// X is both a predecessor and a successor of U.
//
// [N*] //
// ^ ^ //
// / \ //
// [U*] [X]? //
// ^ ^ //
// \ / //
// \ / //
// [Root*] //
//
// * indicates nodes to be folded together.
//
// If Root produces a flag, then it gets (even more) interesting. Since it
// will be "glued" together with its flag use in the scheduler, we need to
// check if it might reach N.
//
// [N*] //
// ^ ^ //
// / \ //
// [U*] [X]? //
// ^ ^ //
// \ \ //
// \ | //
// [Root*] | //
// ^ | //
// f | //
// | / //
// [Y] / //
// ^ / //
// f / //
// | / //
// [FU] //
//
// If FU (flag use) indirectly reaches N (the load), and Root folds N
// (call it Fold), then X is a predecessor of FU and a successor of
// Fold. But since Fold and FU are flagged together, this will create
// a cycle in the scheduling graph.
EVT VT = Root->getValueType(Root->getNumValues()-1);
while (VT == MVT::Flag) {
SDNode *FU = findFlagUse(Root);
if (FU == NULL)
break;
Root = FU;
VT = Root->getValueType(Root->getNumValues()-1);
}
return !isNonImmUse(Root, N.getNode(), U);
}
SDNode *SelectionDAGISel::Select_INLINEASM(SDNode *N) {
std::vector<SDValue> Ops(N->op_begin(), N->op_end());
SelectInlineAsmMemoryOperands(Ops);
std::vector<EVT> VTs;
VTs.push_back(MVT::Other);
VTs.push_back(MVT::Flag);
SDValue New = CurDAG->getNode(ISD::INLINEASM, N->getDebugLoc(),
VTs, &Ops[0], Ops.size());
return New.getNode();
}
SDNode *SelectionDAGISel::Select_UNDEF(SDNode *N) {
return CurDAG->SelectNodeTo(N, TargetOpcode::IMPLICIT_DEF,N->getValueType(0));
}
SDNode *SelectionDAGISel::Select_EH_LABEL(SDNode *N) {
SDValue Chain = N->getOperand(0);
unsigned C = cast<LabelSDNode>(N)->getLabelID();
SDValue Tmp = CurDAG->getTargetConstant(C, MVT::i32);
return CurDAG->SelectNodeTo(N, TargetOpcode::EH_LABEL,
MVT::Other, Tmp, Chain);
}
/// ChainNotReachable - Returns true if Chain does not reach Op.
static bool ChainNotReachable(SDNode *Chain, SDNode *Op) {
if (Chain->getOpcode() == ISD::EntryToken)
return true;
if (Chain->getOpcode() == ISD::TokenFactor)
return false;
if (Chain->getNumOperands() > 0) {
SDValue C0 = Chain->getOperand(0);
if (C0.getValueType() == MVT::Other)
return C0.getNode() != Op && ChainNotReachable(C0.getNode(), Op);
}
return true;
}
/// IsChainCompatible - Returns true if Chain is Op or Chain does not reach Op.
/// This is used to ensure that there are no nodes trapped between Chain, which
/// is the first chain node discovered in a pattern and Op, a later node, that
/// will not be selected into the pattern.
static bool IsChainCompatible(SDNode *Chain, SDNode *Op) {
return Chain == Op || ChainNotReachable(Chain, Op);
}
/// GetVBR - decode a vbr encoding whose top bit is set.
ALWAYS_INLINE static uint64_t
GetVBR(uint64_t Val, const unsigned char *MatcherTable, unsigned &Idx) {
assert(Val >= 128 && "Not a VBR");
Val &= 127; // Remove first vbr bit.
unsigned Shift = 7;
uint64_t NextBits;
do {
NextBits = MatcherTable[Idx++];
Val |= (NextBits&127) << Shift;
Shift += 7;
} while (NextBits & 128);
return Val;
}
/// UpdateChainsAndFlags - When a match is complete, this method updates uses of
/// interior flag and chain results to use the new flag and chain results.
static void UpdateChainsAndFlags(SDNode *NodeToMatch, SDValue InputChain,
const SmallVectorImpl<SDNode*> &ChainNodesMatched,
SDValue InputFlag,
const SmallVectorImpl<SDNode*> &FlagResultNodesMatched,
bool isMorphNodeTo, SelectionDAG *CurDAG) {
// Now that all the normal results are replaced, we replace the chain and
// flag results if present.
if (!ChainNodesMatched.empty()) {
assert(InputChain.getNode() != 0 &&
"Matched input chains but didn't produce a chain");
// Loop over all of the nodes we matched that produced a chain result.
// Replace all the chain results with the final chain we ended up with.
for (unsigned i = 0, e = ChainNodesMatched.size(); i != e; ++i) {
SDNode *ChainNode = ChainNodesMatched[i];
// Don't replace the results of the root node if we're doing a
// MorphNodeTo.
if (ChainNode == NodeToMatch && isMorphNodeTo)
continue;
SDValue ChainVal = SDValue(ChainNode, ChainNode->getNumValues()-1);
if (ChainVal.getValueType() == MVT::Flag)
ChainVal = ChainVal.getValue(ChainVal->getNumValues()-2);
assert(ChainVal.getValueType() == MVT::Other && "Not a chain?");
CurDAG->ReplaceAllUsesOfValueWith(ChainVal, InputChain);
}
}
// If the result produces a flag, update any flag results in the matched
// pattern with the flag result.
if (InputFlag.getNode() != 0) {
// Handle any interior nodes explicitly marked.
for (unsigned i = 0, e = FlagResultNodesMatched.size(); i != e; ++i) {
SDNode *FRN = FlagResultNodesMatched[i];
assert(FRN->getValueType(FRN->getNumValues()-1) == MVT::Flag &&
"Doesn't have a flag result");
CurDAG->ReplaceAllUsesOfValueWith(SDValue(FRN, FRN->getNumValues()-1),
InputFlag);
}
}
DEBUG(errs() << "ISEL: Match complete!\n");
}
/// HandleMergeInputChains - This implements the OPC_EmitMergeInputChains
/// operation for when the pattern matched multiple nodes with chains.
static SDValue
HandleMergeInputChains(const SmallVectorImpl<SDNode*> &ChainNodesMatched,
SelectionDAG *CurDAG) {
assert(ChainNodesMatched.size() > 1 &&
"Should only happen for multi chain node case");
// Walk all the chained nodes, adding the input chains if they are not in
// ChainedNodes (and this, not in the matched pattern). This is an N^2
// algorithm, but # chains is usually 2 here, at most 3 for MSP430.
SmallVector<SDValue, 3> InputChains;
for (unsigned i = 0, e = ChainNodesMatched.size(); i != e; ++i) {
SDValue InChain = ChainNodesMatched[i]->getOperand(0);
assert(InChain.getValueType() == MVT::Other && "Not a chain");
bool Invalid = false;
for (unsigned j = 0; j != e; ++j)
Invalid |= ChainNodesMatched[j] == InChain.getNode();
if (!Invalid)
InputChains.push_back(InChain);
}
SDValue Res;
if (InputChains.size() == 1)
return InputChains[0];
return CurDAG->getNode(ISD::TokenFactor, ChainNodesMatched[0]->getDebugLoc(),
MVT::Other, &InputChains[0], InputChains.size());
}
struct MatchScope {
/// FailIndex - If this match fails, this is the index to continue with.
unsigned FailIndex;
/// NodeStack - The node stack when the scope was formed.
SmallVector<SDValue, 4> NodeStack;
/// NumRecordedNodes - The number of recorded nodes when the scope was formed.
unsigned NumRecordedNodes;
/// NumMatchedMemRefs - The number of matched memref entries.
unsigned NumMatchedMemRefs;
/// InputChain/InputFlag - The current chain/flag
SDValue InputChain, InputFlag;
/// HasChainNodesMatched - True if the ChainNodesMatched list is non-empty.
bool HasChainNodesMatched, HasFlagResultNodesMatched;
};
SDNode *SelectionDAGISel::
SelectCodeCommon(SDNode *NodeToMatch, const unsigned char *MatcherTable,
unsigned TableSize) {
// FIXME: Should these even be selected? Handle these cases in the caller?
switch (NodeToMatch->getOpcode()) {
default:
break;
case ISD::EntryToken: // These nodes remain the same.
case ISD::BasicBlock:
case ISD::Register:
case ISD::HANDLENODE:
case ISD::TargetConstant:
case ISD::TargetConstantFP:
case ISD::TargetConstantPool:
case ISD::TargetFrameIndex:
case ISD::TargetExternalSymbol:
case ISD::TargetBlockAddress:
case ISD::TargetJumpTable:
case ISD::TargetGlobalTLSAddress:
case ISD::TargetGlobalAddress:
case ISD::TokenFactor:
case ISD::CopyFromReg:
case ISD::CopyToReg:
return 0;
case ISD::AssertSext:
case ISD::AssertZext:
CurDAG->ReplaceAllUsesOfValueWith(SDValue(NodeToMatch, 0),
NodeToMatch->getOperand(0));
return 0;
case ISD::INLINEASM: return Select_INLINEASM(NodeToMatch);
case ISD::EH_LABEL: return Select_EH_LABEL(NodeToMatch);
case ISD::UNDEF: return Select_UNDEF(NodeToMatch);
}
assert(!NodeToMatch->isMachineOpcode() && "Node already selected!");
// Set up the node stack with NodeToMatch as the only node on the stack.
SmallVector<SDValue, 8> NodeStack;
SDValue N = SDValue(NodeToMatch, 0);
NodeStack.push_back(N);
// MatchScopes - Scopes used when matching, if a match failure happens, this
// indicates where to continue checking.
SmallVector<MatchScope, 8> MatchScopes;
// RecordedNodes - This is the set of nodes that have been recorded by the
// state machine.
SmallVector<SDValue, 8> RecordedNodes;
// MatchedMemRefs - This is the set of MemRef's we've seen in the input
// pattern.
SmallVector<MachineMemOperand*, 2> MatchedMemRefs;
// These are the current input chain and flag for use when generating nodes.
// Various Emit operations change these. For example, emitting a copytoreg
// uses and updates these.
SDValue InputChain, InputFlag;
// ChainNodesMatched - If a pattern matches nodes that have input/output
// chains, the OPC_EmitMergeInputChains operation is emitted which indicates
// which ones they are. The result is captured into this list so that we can
// update the chain results when the pattern is complete.
SmallVector<SDNode*, 3> ChainNodesMatched;
SmallVector<SDNode*, 3> FlagResultNodesMatched;
DEBUG(errs() << "ISEL: Starting pattern match on root node: ";
NodeToMatch->dump(CurDAG);
errs() << '\n');
// Determine where to start the interpreter. Normally we start at opcode #0,
// but if the state machine starts with an OPC_SwitchOpcode, then we
// accelerate the first lookup (which is guaranteed to be hot) with the
// OpcodeOffset table.
unsigned MatcherIndex = 0;
if (!OpcodeOffset.empty()) {
// Already computed the OpcodeOffset table, just index into it.
if (N.getOpcode() < OpcodeOffset.size())
MatcherIndex = OpcodeOffset[N.getOpcode()];
DEBUG(errs() << " Initial Opcode index to " << MatcherIndex << "\n");
} else if (MatcherTable[0] == OPC_SwitchOpcode) {
// Otherwise, the table isn't computed, but the state machine does start
// with an OPC_SwitchOpcode instruction. Populate the table now, since this
// is the first time we're selecting an instruction.
unsigned Idx = 1;
while (1) {
// Get the size of this case.
unsigned CaseSize = MatcherTable[Idx++];
if (CaseSize & 128)
CaseSize = GetVBR(CaseSize, MatcherTable, Idx);
if (CaseSize == 0) break;
// Get the opcode, add the index to the table.
unsigned Opc = MatcherTable[Idx++];
if (Opc >= OpcodeOffset.size())
OpcodeOffset.resize((Opc+1)*2);
OpcodeOffset[Opc] = Idx;
Idx += CaseSize;
}
// Okay, do the lookup for the first opcode.
if (N.getOpcode() < OpcodeOffset.size())
MatcherIndex = OpcodeOffset[N.getOpcode()];
}
while (1) {
assert(MatcherIndex < TableSize && "Invalid index");
BuiltinOpcodes Opcode = (BuiltinOpcodes)MatcherTable[MatcherIndex++];
switch (Opcode) {
case OPC_Scope: {
unsigned NumToSkip = MatcherTable[MatcherIndex++];
if (NumToSkip & 128)
NumToSkip = GetVBR(NumToSkip, MatcherTable, MatcherIndex);
assert(NumToSkip != 0 &&
"First entry of OPC_Scope shouldn't be 0, scope has no children?");
// Push a MatchScope which indicates where to go if the first child fails
// to match.
MatchScope NewEntry;
NewEntry.FailIndex = MatcherIndex+NumToSkip;
NewEntry.NodeStack.append(NodeStack.begin(), NodeStack.end());
NewEntry.NumRecordedNodes = RecordedNodes.size();
NewEntry.NumMatchedMemRefs = MatchedMemRefs.size();
NewEntry.InputChain = InputChain;
NewEntry.InputFlag = InputFlag;
NewEntry.HasChainNodesMatched = !ChainNodesMatched.empty();
NewEntry.HasFlagResultNodesMatched = !FlagResultNodesMatched.empty();
MatchScopes.push_back(NewEntry);
continue;
}
case OPC_RecordNode:
// Remember this node, it may end up being an operand in the pattern.
RecordedNodes.push_back(N);
continue;
case OPC_RecordChild0: case OPC_RecordChild1:
case OPC_RecordChild2: case OPC_RecordChild3:
case OPC_RecordChild4: case OPC_RecordChild5:
case OPC_RecordChild6: case OPC_RecordChild7: {
unsigned ChildNo = Opcode-OPC_RecordChild0;
if (ChildNo >= N.getNumOperands())
break; // Match fails if out of range child #.
RecordedNodes.push_back(N->getOperand(ChildNo));
continue;
}
case OPC_RecordMemRef:
MatchedMemRefs.push_back(cast<MemSDNode>(N)->getMemOperand());
continue;
case OPC_CaptureFlagInput:
// If the current node has an input flag, capture it in InputFlag.
if (N->getNumOperands() != 0 &&
N->getOperand(N->getNumOperands()-1).getValueType() == MVT::Flag)
InputFlag = N->getOperand(N->getNumOperands()-1);
continue;
case OPC_MoveChild: {
unsigned ChildNo = MatcherTable[MatcherIndex++];
if (ChildNo >= N.getNumOperands())
break; // Match fails if out of range child #.
N = N.getOperand(ChildNo);
NodeStack.push_back(N);
continue;
}
case OPC_MoveParent:
// Pop the current node off the NodeStack.
NodeStack.pop_back();
assert(!NodeStack.empty() && "Node stack imbalance!");
N = NodeStack.back();
continue;
case OPC_CheckSame: {
// Accept if it is exactly the same as a previously recorded node.
unsigned RecNo = MatcherTable[MatcherIndex++];
assert(RecNo < RecordedNodes.size() && "Invalid CheckSame");
if (N != RecordedNodes[RecNo]) break;
continue;
}
case OPC_CheckPatternPredicate:
if (!CheckPatternPredicate(MatcherTable[MatcherIndex++])) break;
continue;
case OPC_CheckPredicate:
if (!CheckNodePredicate(N.getNode(), MatcherTable[MatcherIndex++])) break;
continue;
case OPC_CheckComplexPat:
if (!CheckComplexPattern(NodeToMatch, N,
MatcherTable[MatcherIndex++], RecordedNodes))
break;
continue;
case OPC_CheckOpcode:
if (N->getOpcode() != MatcherTable[MatcherIndex++]) break;
continue;
case OPC_SwitchOpcode: {
unsigned CurNodeOpcode = N.getOpcode();
unsigned SwitchStart = MatcherIndex-1; (void)SwitchStart;
unsigned CaseSize;
while (1) {
// Get the size of this case.
CaseSize = MatcherTable[MatcherIndex++];
if (CaseSize & 128)
CaseSize = GetVBR(CaseSize, MatcherTable, MatcherIndex);
if (CaseSize == 0) break;
// If the opcode matches, then we will execute this case.
if (CurNodeOpcode == MatcherTable[MatcherIndex++])
break;
// Otherwise, skip over this case.
MatcherIndex += CaseSize;
}
// If we failed to match, bail out.
if (CaseSize == 0) break;
// Otherwise, execute the case we found.
DEBUG(errs() << " OpcodeSwitch from " << SwitchStart
<< " to " << MatcherIndex << "\n");
continue;
}
case OPC_CheckType: {
MVT::SimpleValueType VT =
(MVT::SimpleValueType)MatcherTable[MatcherIndex++];
if (N.getValueType() != VT) {
// Handle the case when VT is iPTR.
if (VT != MVT::iPTR || N.getValueType() != TLI.getPointerTy())
break;
}
continue;
}
case OPC_CheckChild0Type: case OPC_CheckChild1Type:
case OPC_CheckChild2Type: case OPC_CheckChild3Type:
case OPC_CheckChild4Type: case OPC_CheckChild5Type:
case OPC_CheckChild6Type: case OPC_CheckChild7Type: {
unsigned ChildNo = Opcode-OPC_CheckChild0Type;
if (ChildNo >= N.getNumOperands())
break; // Match fails if out of range child #.
MVT::SimpleValueType VT =
(MVT::SimpleValueType)MatcherTable[MatcherIndex++];
EVT ChildVT = N.getOperand(ChildNo).getValueType();
if (ChildVT != VT) {
// Handle the case when VT is iPTR.
if (VT != MVT::iPTR || ChildVT != TLI.getPointerTy())
break;
}
continue;
}
case OPC_CheckCondCode:
if (cast<CondCodeSDNode>(N)->get() !=
(ISD::CondCode)MatcherTable[MatcherIndex++]) break;
continue;
case OPC_CheckValueType: {
MVT::SimpleValueType VT =
(MVT::SimpleValueType)MatcherTable[MatcherIndex++];
if (cast<VTSDNode>(N)->getVT() != VT) {
// Handle the case when VT is iPTR.
if (VT != MVT::iPTR || cast<VTSDNode>(N)->getVT() != TLI.getPointerTy())
break;
}
continue;
}
case OPC_CheckInteger: {
int64_t Val = MatcherTable[MatcherIndex++];
if (Val & 128)
Val = GetVBR(Val, MatcherTable, MatcherIndex);
ConstantSDNode *C = dyn_cast<ConstantSDNode>(N);
if (C == 0 || C->getSExtValue() != Val)
break;
continue;
}
case OPC_CheckAndImm: {
int64_t Val = MatcherTable[MatcherIndex++];
if (Val & 128)
Val = GetVBR(Val, MatcherTable, MatcherIndex);
if (N->getOpcode() != ISD::AND) break;
ConstantSDNode *C = dyn_cast<ConstantSDNode>(N->getOperand(1));
if (C == 0 || !CheckAndMask(N.getOperand(0), C, Val))
break;
continue;
}
case OPC_CheckOrImm: {
int64_t Val = MatcherTable[MatcherIndex++];
if (Val & 128)
Val = GetVBR(Val, MatcherTable, MatcherIndex);
if (N->getOpcode() != ISD::OR) break;
ConstantSDNode *C = dyn_cast<ConstantSDNode>(N->getOperand(1));
if (C == 0 || !CheckOrMask(N.getOperand(0), C, Val))
break;
continue;
}
case OPC_CheckFoldableChainNode: {
assert(NodeStack.size() != 1 && "No parent node");
// Verify that all intermediate nodes between the root and this one have
// a single use.
bool HasMultipleUses = false;
for (unsigned i = 1, e = NodeStack.size()-1; i != e; ++i)
if (!NodeStack[i].hasOneUse()) {
HasMultipleUses = true;
break;
}
if (HasMultipleUses) break;
// Check to see that the target thinks this is profitable to fold and that
// we can fold it without inducing cycles in the graph.
if (!IsProfitableToFold(N, NodeStack[NodeStack.size()-2].getNode(),
NodeToMatch) ||
!IsLegalToFold(N, NodeStack[NodeStack.size()-2].getNode(),
NodeToMatch))
break;
continue;
}
case OPC_CheckChainCompatible: {
unsigned PrevNode = MatcherTable[MatcherIndex++];
assert(PrevNode < RecordedNodes.size() && "Invalid CheckChainCompatible");
SDValue PrevChainedNode = RecordedNodes[PrevNode];
SDValue ThisChainedNode = RecordedNodes.back();
// We have two nodes with chains, verify that their input chains are good.
assert(PrevChainedNode.getOperand(0).getValueType() == MVT::Other &&
ThisChainedNode.getOperand(0).getValueType() == MVT::Other &&
"Invalid chained nodes");
if (!IsChainCompatible(// Input chain of the previous node.
PrevChainedNode.getOperand(0).getNode(),
// Node with chain.
ThisChainedNode.getNode()))
break;
continue;
}
case OPC_EmitInteger: {
MVT::SimpleValueType VT =
(MVT::SimpleValueType)MatcherTable[MatcherIndex++];
int64_t Val = MatcherTable[MatcherIndex++];
if (Val & 128)
Val = GetVBR(Val, MatcherTable, MatcherIndex);
RecordedNodes.push_back(CurDAG->getTargetConstant(Val, VT));
continue;
}
case OPC_EmitRegister: {
MVT::SimpleValueType VT =
(MVT::SimpleValueType)MatcherTable[MatcherIndex++];
unsigned RegNo = MatcherTable[MatcherIndex++];
RecordedNodes.push_back(CurDAG->getRegister(RegNo, VT));
continue;
}
case OPC_EmitConvertToTarget: {
// Convert from IMM/FPIMM to target version.
unsigned RecNo = MatcherTable[MatcherIndex++];
assert(RecNo < RecordedNodes.size() && "Invalid CheckSame");
SDValue Imm = RecordedNodes[RecNo];
if (Imm->getOpcode() == ISD::Constant) {
int64_t Val = cast<ConstantSDNode>(Imm)->getZExtValue();
Imm = CurDAG->getTargetConstant(Val, Imm.getValueType());
} else if (Imm->getOpcode() == ISD::ConstantFP) {
const ConstantFP *Val=cast<ConstantFPSDNode>(Imm)->getConstantFPValue();
Imm = CurDAG->getTargetConstantFP(*Val, Imm.getValueType());
}
RecordedNodes.push_back(Imm);
continue;
}
case OPC_EmitMergeInputChains: {
assert(InputChain.getNode() == 0 &&
"EmitMergeInputChains should be the first chain producing node");
// This node gets a list of nodes we matched in the input that have
// chains. We want to token factor all of the input chains to these nodes
// together. However, if any of the input chains is actually one of the
// nodes matched in this pattern, then we have an intra-match reference.
// Ignore these because the newly token factored chain should not refer to
// the old nodes.
unsigned NumChains = MatcherTable[MatcherIndex++];
assert(NumChains != 0 && "Can't TF zero chains");
assert(ChainNodesMatched.empty() &&
"Should only have one EmitMergeInputChains per match");
// Handle the first chain.
unsigned RecNo = MatcherTable[MatcherIndex++];
assert(RecNo < RecordedNodes.size() && "Invalid CheckSame");
ChainNodesMatched.push_back(RecordedNodes[RecNo].getNode());
// If the chained node is not the root, we can't fold it if it has
// multiple uses.
// FIXME: What if other value results of the node have uses not matched by
// this pattern?
if (ChainNodesMatched.back() != NodeToMatch &&
!RecordedNodes[RecNo].hasOneUse()) {
ChainNodesMatched.clear();
break;
}
// The common case here is that we have exactly one chain, which is really
// cheap to handle, just do it.
if (NumChains == 1) {
InputChain = RecordedNodes[RecNo].getOperand(0);
assert(InputChain.getValueType() == MVT::Other && "Not a chain");
continue;
}
// Read all of the chained nodes.
for (unsigned i = 1; i != NumChains; ++i) {
RecNo = MatcherTable[MatcherIndex++];
assert(RecNo < RecordedNodes.size() && "Invalid CheckSame");
ChainNodesMatched.push_back(RecordedNodes[RecNo].getNode());
// FIXME: What if other value results of the node have uses not matched
// by this pattern?
if (ChainNodesMatched.back() != NodeToMatch &&
!RecordedNodes[RecNo].hasOneUse()) {
ChainNodesMatched.clear();
break;
}
}
// If the inner loop broke out, the match fails.
if (ChainNodesMatched.empty())
break;
// Merge the input chains if they are not intra-pattern references.
InputChain = HandleMergeInputChains(ChainNodesMatched, CurDAG);
if (InputChain.getNode() == 0)
break; // Failed to merge.
continue;
}
case OPC_EmitCopyToReg: {
unsigned RecNo = MatcherTable[MatcherIndex++];
assert(RecNo < RecordedNodes.size() && "Invalid CheckSame");
unsigned DestPhysReg = MatcherTable[MatcherIndex++];
if (InputChain.getNode() == 0)
InputChain = CurDAG->getEntryNode();
InputChain = CurDAG->getCopyToReg(InputChain, NodeToMatch->getDebugLoc(),
DestPhysReg, RecordedNodes[RecNo],
InputFlag);
InputFlag = InputChain.getValue(1);
continue;
}
case OPC_EmitNodeXForm: {
unsigned XFormNo = MatcherTable[MatcherIndex++];
unsigned RecNo = MatcherTable[MatcherIndex++];
assert(RecNo < RecordedNodes.size() && "Invalid CheckSame");
RecordedNodes.push_back(RunSDNodeXForm(RecordedNodes[RecNo], XFormNo));
continue;
}
case OPC_EmitNode:
case OPC_MorphNodeTo: {
uint16_t TargetOpc = MatcherTable[MatcherIndex++];
TargetOpc |= (unsigned short)MatcherTable[MatcherIndex++] << 8;
unsigned EmitNodeInfo = MatcherTable[MatcherIndex++];
// Get the result VT list.
unsigned NumVTs = MatcherTable[MatcherIndex++];
SmallVector<EVT, 4> VTs;
for (unsigned i = 0; i != NumVTs; ++i) {
MVT::SimpleValueType VT =
(MVT::SimpleValueType)MatcherTable[MatcherIndex++];
if (VT == MVT::iPTR) VT = TLI.getPointerTy().SimpleTy;
VTs.push_back(VT);
}
if (EmitNodeInfo & OPFL_Chain)
VTs.push_back(MVT::Other);
if (EmitNodeInfo & OPFL_FlagOutput)
VTs.push_back(MVT::Flag);
// This is hot code, so optimize the two most common cases of 1 and 2
// results.
SDVTList VTList;
if (VTs.size() == 1)
VTList = CurDAG->getVTList(VTs[0]);
else if (VTs.size() == 2)
VTList = CurDAG->getVTList(VTs[0], VTs[1]);
else
VTList = CurDAG->getVTList(VTs.data(), VTs.size());
// Get the operand list.
unsigned NumOps = MatcherTable[MatcherIndex++];
SmallVector<SDValue, 8> Ops;
for (unsigned i = 0; i != NumOps; ++i) {
unsigned RecNo = MatcherTable[MatcherIndex++];
if (RecNo & 128)
RecNo = GetVBR(RecNo, MatcherTable, MatcherIndex);
assert(RecNo < RecordedNodes.size() && "Invalid EmitNode");
Ops.push_back(RecordedNodes[RecNo]);
}
// If there are variadic operands to add, handle them now.
if (EmitNodeInfo & OPFL_VariadicInfo) {
// Determine the start index to copy from.
unsigned FirstOpToCopy = getNumFixedFromVariadicInfo(EmitNodeInfo);
FirstOpToCopy += (EmitNodeInfo & OPFL_Chain) ? 1 : 0;
assert(NodeToMatch->getNumOperands() >= FirstOpToCopy &&
"Invalid variadic node");
// Copy all of the variadic operands, not including a potential flag
// input.
for (unsigned i = FirstOpToCopy, e = NodeToMatch->getNumOperands();
i != e; ++i) {
SDValue V = NodeToMatch->getOperand(i);
if (V.getValueType() == MVT::Flag) break;
Ops.push_back(V);
}
}
// If this has chain/flag inputs, add them.
if (EmitNodeInfo & OPFL_Chain)
Ops.push_back(InputChain);
if ((EmitNodeInfo & OPFL_FlagInput) && InputFlag.getNode() != 0)
Ops.push_back(InputFlag);
// Create the node.
SDNode *Res = 0;
if (Opcode != OPC_MorphNodeTo) {
// If this is a normal EmitNode command, just create the new node and
// add the results to the RecordedNodes list.
Res = CurDAG->getMachineNode(TargetOpc, NodeToMatch->getDebugLoc(),
VTList, Ops.data(), Ops.size());
// Add all the non-flag/non-chain results to the RecordedNodes list.
for (unsigned i = 0, e = VTs.size(); i != e; ++i) {
if (VTs[i] == MVT::Other || VTs[i] == MVT::Flag) break;
RecordedNodes.push_back(SDValue(Res, i));
}
} else {
// It is possible we're using MorphNodeTo to replace a node with no
// normal results with one that has a normal result (or we could be
// adding a chain) and the input could have flags and chains as well.
// In this case we need to shifting the operands down.
// FIXME: This is a horrible hack and broken in obscure cases, no worse
// than the old isel though. We should sink this into MorphNodeTo.
int OldFlagResultNo = -1, OldChainResultNo = -1;
unsigned NTMNumResults = NodeToMatch->getNumValues();
if (NodeToMatch->getValueType(NTMNumResults-1) == MVT::Flag) {
OldFlagResultNo = NTMNumResults-1;
if (NTMNumResults != 1 &&
NodeToMatch->getValueType(NTMNumResults-2) == MVT::Other)
OldChainResultNo = NTMNumResults-2;
} else if (NodeToMatch->getValueType(NTMNumResults-1) == MVT::Other)
OldChainResultNo = NTMNumResults-1;
Res = CurDAG->MorphNodeTo(NodeToMatch, ~TargetOpc, VTList,
Ops.data(), Ops.size());
// MorphNodeTo can operate in two ways: if an existing node with the
// specified operands exists, it can just return it. Otherwise, it
// updates the node in place to have the requested operands.
if (Res == NodeToMatch) {
// If we updated the node in place, reset the node ID. To the isel,
// this should be just like a newly allocated machine node.
Res->setNodeId(-1);
}
unsigned ResNumResults = Res->getNumValues();
// Move the flag if needed.
if ((EmitNodeInfo & OPFL_FlagOutput) && OldFlagResultNo != -1 &&
(unsigned)OldFlagResultNo != ResNumResults-1)
CurDAG->ReplaceAllUsesOfValueWith(SDValue(NodeToMatch,
OldFlagResultNo),
SDValue(Res, ResNumResults-1));
if ((EmitNodeInfo & OPFL_FlagOutput) != 0)
--ResNumResults;
// Move the chain reference if needed.
if ((EmitNodeInfo & OPFL_Chain) && OldChainResultNo != -1 &&
(unsigned)OldChainResultNo != ResNumResults-1)
CurDAG->ReplaceAllUsesOfValueWith(SDValue(NodeToMatch,
OldChainResultNo),
SDValue(Res, ResNumResults-1));
if (Res != NodeToMatch) {
// Otherwise, no replacement happened because the node already exists.
CurDAG->ReplaceAllUsesWith(NodeToMatch, Res);
}
}
// If the node had chain/flag results, update our notion of the current
// chain and flag.
if (VTs.back() == MVT::Flag) {
InputFlag = SDValue(Res, VTs.size()-1);
if (EmitNodeInfo & OPFL_Chain)
InputChain = SDValue(Res, VTs.size()-2);
} else if (EmitNodeInfo & OPFL_Chain)
InputChain = SDValue(Res, VTs.size()-1);
// If the OPFL_MemRefs flag is set on this node, slap all of the
// accumulated memrefs onto it.
//
// FIXME: This is vastly incorrect for patterns with multiple outputs
// instructions that access memory and for ComplexPatterns that match
// loads.
if (EmitNodeInfo & OPFL_MemRefs) {
MachineSDNode::mmo_iterator MemRefs =
MF->allocateMemRefsArray(MatchedMemRefs.size());
std::copy(MatchedMemRefs.begin(), MatchedMemRefs.end(), MemRefs);
cast<MachineSDNode>(Res)
->setMemRefs(MemRefs, MemRefs + MatchedMemRefs.size());
}
DEBUG(errs() << " "
<< (Opcode == OPC_MorphNodeTo ? "Morphed" : "Created")
<< " node: "; Res->dump(CurDAG); errs() << "\n");
// If this was a MorphNodeTo then we're completely done!
if (Opcode == OPC_MorphNodeTo) {
// Update chain and flag uses.
UpdateChainsAndFlags(NodeToMatch, InputChain, ChainNodesMatched,
InputFlag, FlagResultNodesMatched, true, CurDAG);
return 0;
}
continue;
}
case OPC_MarkFlagResults: {
unsigned NumNodes = MatcherTable[MatcherIndex++];
// Read and remember all the flag-result nodes.
for (unsigned i = 0; i != NumNodes; ++i) {
unsigned RecNo = MatcherTable[MatcherIndex++];
if (RecNo & 128)
RecNo = GetVBR(RecNo, MatcherTable, MatcherIndex);
assert(RecNo < RecordedNodes.size() && "Invalid CheckSame");
FlagResultNodesMatched.push_back(RecordedNodes[RecNo].getNode());
}
continue;
}
case OPC_CompleteMatch: {
// The match has been completed, and any new nodes (if any) have been
// created. Patch up references to the matched dag to use the newly
// created nodes.
unsigned NumResults = MatcherTable[MatcherIndex++];
for (unsigned i = 0; i != NumResults; ++i) {
unsigned ResSlot = MatcherTable[MatcherIndex++];
if (ResSlot & 128)
ResSlot = GetVBR(ResSlot, MatcherTable, MatcherIndex);
assert(ResSlot < RecordedNodes.size() && "Invalid CheckSame");
SDValue Res = RecordedNodes[ResSlot];
// FIXME2: Eliminate this horrible hack by fixing the 'Gen' program
// after (parallel) on input patterns are removed. This would also
// allow us to stop encoding #results in OPC_CompleteMatch's table
// entry.
if (NodeToMatch->getNumValues() <= i ||
NodeToMatch->getValueType(i) == MVT::Other ||
NodeToMatch->getValueType(i) == MVT::Flag)
break;
assert((NodeToMatch->getValueType(i) == Res.getValueType() ||
NodeToMatch->getValueType(i) == MVT::iPTR ||
Res.getValueType() == MVT::iPTR ||
NodeToMatch->getValueType(i).getSizeInBits() ==
Res.getValueType().getSizeInBits()) &&
"invalid replacement");
CurDAG->ReplaceAllUsesOfValueWith(SDValue(NodeToMatch, i), Res);
}
// If the root node defines a flag, add it to the flag nodes to update
// list.
if (NodeToMatch->getValueType(NodeToMatch->getNumValues()-1) == MVT::Flag)
FlagResultNodesMatched.push_back(NodeToMatch);
// Update chain and flag uses.
UpdateChainsAndFlags(NodeToMatch, InputChain, ChainNodesMatched,
InputFlag, FlagResultNodesMatched, false, CurDAG);
assert(NodeToMatch->use_empty() &&
"Didn't replace all uses of the node?");
// FIXME: We just return here, which interacts correctly with SelectRoot
// above. We should fix this to not return an SDNode* anymore.
return 0;
}
}
// If the code reached this point, then the match failed. See if there is
// another child to try in the current 'Scope', otherwise pop it until we
// find a case to check.
while (1) {
if (MatchScopes.empty()) {
CannotYetSelect(NodeToMatch);
return 0;
}
// Restore the interpreter state back to the point where the scope was
// formed.
MatchScope &LastScope = MatchScopes.back();
RecordedNodes.resize(LastScope.NumRecordedNodes);
NodeStack.clear();
NodeStack.append(LastScope.NodeStack.begin(), LastScope.NodeStack.end());
N = NodeStack.back();
DEBUG(errs() << " Match failed at index " << MatcherIndex
<< " continuing at " << LastScope.FailIndex << "\n");
if (LastScope.NumMatchedMemRefs != MatchedMemRefs.size())
MatchedMemRefs.resize(LastScope.NumMatchedMemRefs);
MatcherIndex = LastScope.FailIndex;
InputChain = LastScope.InputChain;
InputFlag = LastScope.InputFlag;
if (!LastScope.HasChainNodesMatched)
ChainNodesMatched.clear();
if (!LastScope.HasFlagResultNodesMatched)
FlagResultNodesMatched.clear();
// Check to see what the offset is at the new MatcherIndex. If it is zero
// we have reached the end of this scope, otherwise we have another child
// in the current scope to try.
unsigned NumToSkip = MatcherTable[MatcherIndex++];
if (NumToSkip & 128)
NumToSkip = GetVBR(NumToSkip, MatcherTable, MatcherIndex);
// If we have another child in this scope to match, update FailIndex and
// try it.
if (NumToSkip != 0) {
LastScope.FailIndex = MatcherIndex+NumToSkip;
break;
}
// End of this scope, pop it and try the next child in the containing
// scope.
MatchScopes.pop_back();
}
}
}
void SelectionDAGISel::CannotYetSelect(SDNode *N) {
if (N->getOpcode() == ISD::INTRINSIC_W_CHAIN ||
N->getOpcode() == ISD::INTRINSIC_WO_CHAIN ||
N->getOpcode() == ISD::INTRINSIC_VOID)
return CannotYetSelectIntrinsic(N);
std::string msg;
raw_string_ostream Msg(msg);
Msg << "Cannot yet select: ";
N->printrFull(Msg, CurDAG);
llvm_report_error(Msg.str());
}
void SelectionDAGISel::CannotYetSelectIntrinsic(SDNode *N) {
dbgs() << "Cannot yet select: ";
unsigned iid =
cast<ConstantSDNode>(N->getOperand(N->getOperand(0).getValueType() ==
MVT::Other))->getZExtValue();
if (iid < Intrinsic::num_intrinsics)
llvm_report_error("Cannot yet select: intrinsic %" +
Intrinsic::getName((Intrinsic::ID)iid));
else if (const TargetIntrinsicInfo *tii = TM.getIntrinsicInfo())
llvm_report_error(Twine("Cannot yet select: target intrinsic %") +
tii->getName(iid));
}
char SelectionDAGISel::ID = 0;
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