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Sooooo many of these had incorrect or strange main module includes. I have manually inspected all of these, and fixed the main module include to be the nearest plausible thing I could find. If you own or care about any of these source files, I encourage you to take some time and check that these edits were sensible. I can't have broken anything (I strictly added headers, and reordered them, never removed), but they may not be the headers you'd really like to identify as containing the API being implemented. Many forward declarations and missing includes were added to a header files to allow them to parse cleanly when included first. The main module rule does in fact have its merits. =] git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169131 91177308-0d34-0410-b5e6-96231b3b80d8
175 lines
6.0 KiB
C++
175 lines
6.0 KiB
C++
//===- LoopInstSimplify.cpp - Loop Instruction Simplification Pass --------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This pass performs lightweight instruction simplification on loop bodies.
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//
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//===----------------------------------------------------------------------===//
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#define DEBUG_TYPE "loop-instsimplify"
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#include "llvm/Transforms/Scalar.h"
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#include "llvm/ADT/Statistic.h"
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#include "llvm/Analysis/Dominators.h"
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#include "llvm/Analysis/InstructionSimplify.h"
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#include "llvm/Analysis/LoopInfo.h"
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#include "llvm/Analysis/LoopPass.h"
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#include "llvm/DataLayout.h"
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#include "llvm/Instructions.h"
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#include "llvm/Support/Debug.h"
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#include "llvm/Target/TargetLibraryInfo.h"
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#include "llvm/Transforms/Utils/Local.h"
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using namespace llvm;
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STATISTIC(NumSimplified, "Number of redundant instructions simplified");
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namespace {
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class LoopInstSimplify : public LoopPass {
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public:
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static char ID; // Pass ID, replacement for typeid
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LoopInstSimplify() : LoopPass(ID) {
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initializeLoopInstSimplifyPass(*PassRegistry::getPassRegistry());
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}
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bool runOnLoop(Loop*, LPPassManager&);
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virtual void getAnalysisUsage(AnalysisUsage &AU) const {
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AU.setPreservesCFG();
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AU.addRequired<LoopInfo>();
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AU.addRequiredID(LoopSimplifyID);
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AU.addPreservedID(LoopSimplifyID);
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AU.addPreservedID(LCSSAID);
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AU.addPreserved("scalar-evolution");
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AU.addRequired<TargetLibraryInfo>();
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}
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};
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}
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char LoopInstSimplify::ID = 0;
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INITIALIZE_PASS_BEGIN(LoopInstSimplify, "loop-instsimplify",
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"Simplify instructions in loops", false, false)
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INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfo)
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INITIALIZE_PASS_DEPENDENCY(DominatorTree)
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INITIALIZE_PASS_DEPENDENCY(LoopInfo)
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INITIALIZE_PASS_DEPENDENCY(LCSSA)
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INITIALIZE_PASS_END(LoopInstSimplify, "loop-instsimplify",
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"Simplify instructions in loops", false, false)
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Pass *llvm::createLoopInstSimplifyPass() {
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return new LoopInstSimplify();
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}
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bool LoopInstSimplify::runOnLoop(Loop *L, LPPassManager &LPM) {
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DominatorTree *DT = getAnalysisIfAvailable<DominatorTree>();
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LoopInfo *LI = &getAnalysis<LoopInfo>();
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const DataLayout *TD = getAnalysisIfAvailable<DataLayout>();
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const TargetLibraryInfo *TLI = &getAnalysis<TargetLibraryInfo>();
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SmallVector<BasicBlock*, 8> ExitBlocks;
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L->getUniqueExitBlocks(ExitBlocks);
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array_pod_sort(ExitBlocks.begin(), ExitBlocks.end());
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SmallPtrSet<const Instruction*, 8> S1, S2, *ToSimplify = &S1, *Next = &S2;
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// The bit we are stealing from the pointer represents whether this basic
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// block is the header of a subloop, in which case we only process its phis.
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typedef PointerIntPair<BasicBlock*, 1> WorklistItem;
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SmallVector<WorklistItem, 16> VisitStack;
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SmallPtrSet<BasicBlock*, 32> Visited;
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bool Changed = false;
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bool LocalChanged;
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do {
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LocalChanged = false;
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VisitStack.clear();
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Visited.clear();
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VisitStack.push_back(WorklistItem(L->getHeader(), false));
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while (!VisitStack.empty()) {
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WorklistItem Item = VisitStack.pop_back_val();
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BasicBlock *BB = Item.getPointer();
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bool IsSubloopHeader = Item.getInt();
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// Simplify instructions in the current basic block.
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for (BasicBlock::iterator BI = BB->begin(), BE = BB->end(); BI != BE;) {
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Instruction *I = BI++;
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// The first time through the loop ToSimplify is empty and we try to
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// simplify all instructions. On later iterations ToSimplify is not
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// empty and we only bother simplifying instructions that are in it.
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if (!ToSimplify->empty() && !ToSimplify->count(I))
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continue;
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// Don't bother simplifying unused instructions.
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if (!I->use_empty()) {
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Value *V = SimplifyInstruction(I, TD, TLI, DT);
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if (V && LI->replacementPreservesLCSSAForm(I, V)) {
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// Mark all uses for resimplification next time round the loop.
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for (Value::use_iterator UI = I->use_begin(), UE = I->use_end();
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UI != UE; ++UI)
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Next->insert(cast<Instruction>(*UI));
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I->replaceAllUsesWith(V);
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LocalChanged = true;
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++NumSimplified;
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}
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}
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LocalChanged |= RecursivelyDeleteTriviallyDeadInstructions(I, TLI);
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if (IsSubloopHeader && !isa<PHINode>(I))
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break;
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}
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// Add all successors to the worklist, except for loop exit blocks and the
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// bodies of subloops. We visit the headers of loops so that we can process
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// their phis, but we contract the rest of the subloop body and only follow
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// edges leading back to the original loop.
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for (succ_iterator SI = succ_begin(BB), SE = succ_end(BB); SI != SE;
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++SI) {
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BasicBlock *SuccBB = *SI;
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if (!Visited.insert(SuccBB))
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continue;
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const Loop *SuccLoop = LI->getLoopFor(SuccBB);
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if (SuccLoop && SuccLoop->getHeader() == SuccBB
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&& L->contains(SuccLoop)) {
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VisitStack.push_back(WorklistItem(SuccBB, true));
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SmallVector<BasicBlock*, 8> SubLoopExitBlocks;
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SuccLoop->getExitBlocks(SubLoopExitBlocks);
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for (unsigned i = 0; i < SubLoopExitBlocks.size(); ++i) {
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BasicBlock *ExitBB = SubLoopExitBlocks[i];
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if (LI->getLoopFor(ExitBB) == L && Visited.insert(ExitBB))
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VisitStack.push_back(WorklistItem(ExitBB, false));
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}
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continue;
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}
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bool IsExitBlock = std::binary_search(ExitBlocks.begin(),
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ExitBlocks.end(), SuccBB);
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if (IsExitBlock)
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continue;
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VisitStack.push_back(WorklistItem(SuccBB, false));
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}
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}
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// Place the list of instructions to simplify on the next loop iteration
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// into ToSimplify.
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std::swap(ToSimplify, Next);
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Next->clear();
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Changed |= LocalChanged;
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} while (LocalChanged);
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return Changed;
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}
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