From 901a27d892662899071ce9794adaa6b23408f68c Mon Sep 17 00:00:00 2001 From: Devang Patel Date: Wed, 7 Mar 2007 00:26:10 +0000 Subject: [PATCH] Now LoopUnswitch is a LoopPass. llvm-svn: 34992 --- llvm/include/llvm/Transforms/Scalar.h | 2 +- llvm/lib/Analysis/LoopPass.cpp | 3 +- llvm/lib/Transforms/Scalar/LoopUnswitch.cpp | 103 ++++---------------- llvm/tools/opt/opt.cpp | 1 + 4 files changed, 21 insertions(+), 88 deletions(-) diff --git a/llvm/include/llvm/Transforms/Scalar.h b/llvm/include/llvm/Transforms/Scalar.h index 0ce0f3faac37..1d6445c64e36 100644 --- a/llvm/include/llvm/Transforms/Scalar.h +++ b/llvm/include/llvm/Transforms/Scalar.h @@ -127,7 +127,7 @@ LoopPass *createLoopStrengthReducePass(const TargetLowering *TLI = NULL); // // LoopUnswitch - This pass is a simple loop unswitching pass. // -FunctionPass *createLoopUnswitchPass(); +LoopPass *createLoopUnswitchPass(); //===----------------------------------------------------------------------===// // diff --git a/llvm/lib/Analysis/LoopPass.cpp b/llvm/lib/Analysis/LoopPass.cpp index d44e41a63713..ac2e32c51cfe 100644 --- a/llvm/lib/Analysis/LoopPass.cpp +++ b/llvm/lib/Analysis/LoopPass.cpp @@ -132,7 +132,7 @@ void LPPassManager::insertLoop(Loop *L, Loop *ParentLoop) { // queue. This allows LoopPass to change loop nest for the loop. This // utility may send LPPassManager into infinite loops so use caution. void LPPassManager::redoLoop(Loop *L) { - assert (CurrentLoop != L && "Can redo only CurrentLoop"); + assert (CurrentLoop == L && "Can redo only CurrentLoop"); redoThisLoop = true; } @@ -279,6 +279,7 @@ void LoopPass::assignPassManager(PMStack &PMS, // [1] Create new Call Graph Pass Manager LPPM = new LPPassManager(PMD->getDepth() + 1); + LPPM->populateInheritedAnalysis(PMS); // [2] Set up new manager's top level manager PMTopLevelManager *TPM = PMD->getTopLevelManager(); diff --git a/llvm/lib/Transforms/Scalar/LoopUnswitch.cpp b/llvm/lib/Transforms/Scalar/LoopUnswitch.cpp index 5274c9dd107c..77dfb908fa77 100644 --- a/llvm/lib/Transforms/Scalar/LoopUnswitch.cpp +++ b/llvm/lib/Transforms/Scalar/LoopUnswitch.cpp @@ -34,6 +34,7 @@ #include "llvm/Instructions.h" #include "llvm/Analysis/ConstantFolding.h" #include "llvm/Analysis/LoopInfo.h" +#include "llvm/Analysis/LoopPass.h" #include "llvm/Transforms/Utils/Cloning.h" #include "llvm/Transforms/Utils/Local.h" #include "llvm/Transforms/Utils/BasicBlockUtils.h" @@ -58,16 +59,17 @@ namespace { Threshold("loop-unswitch-threshold", cl::desc("Max loop size to unswitch"), cl::init(10), cl::Hidden); - class VISIBILITY_HIDDEN LoopUnswitch : public FunctionPass { + class VISIBILITY_HIDDEN LoopUnswitch : public LoopPass { LoopInfo *LI; // Loop information + LPPassManager *LPM; - // LoopProcessWorklist - List of loops we need to process. + // LoopProcessWorklist - Used to check if second loop needs processing + // after RewriteLoopBodyWithConditionConstant rewrites first loop. std::vector LoopProcessWorklist; SmallPtrSet UnswitchedVals; public: - virtual bool runOnFunction(Function &F); - bool visitLoop(Loop *L); + bool runOnLoop(Loop *L, LPPassManager &LPM); /// This transformation requires natural loop information & requires that /// loop preheaders be inserted into the CFG... @@ -110,29 +112,7 @@ namespace { RegisterPass X("loop-unswitch", "Unswitch loops"); } -FunctionPass *llvm::createLoopUnswitchPass() { return new LoopUnswitch(); } - -bool LoopUnswitch::runOnFunction(Function &F) { - bool Changed = false; - LI = &getAnalysis(); - - // Populate the worklist of loops to process in post-order. - for (LoopInfo::iterator I = LI->begin(), E = LI->end(); I != E; ++I) - for (po_iterator LI = po_begin(*I), E = po_end(*I); LI != E; ++LI) - LoopProcessWorklist.push_back(*LI); - - // Process the loops in worklist order, this is a post-order visitation of - // the loops. We use a worklist of loops so that loops can be removed at any - // time if they are deleted (e.g. the backedge of a loop is removed). - while (!LoopProcessWorklist.empty()) { - Loop *L = LoopProcessWorklist.back(); - LoopProcessWorklist.pop_back(); - Changed |= visitLoop(L); - } - - UnswitchedVals.clear(); - return Changed; -} +LoopPass *llvm::createLoopUnswitchPass() { return new LoopUnswitch(); } /// FindLIVLoopCondition - Cond is a condition that occurs in L. If it is /// invariant in the loop, or has an invariant piece, return the invariant. @@ -160,9 +140,10 @@ static Value *FindLIVLoopCondition(Value *Cond, Loop *L, bool &Changed) { return 0; } -bool LoopUnswitch::visitLoop(Loop *L) { +bool LoopUnswitch::runOnLoop(Loop *L, LPPassManager &LPM_Ref) { assert(L->isLCSSAForm()); - + LI = &getAnalysis(); + LPM = &LPM_Ref; bool Changed = false; // Loop over all of the basic blocks in the loop. If we find an interior @@ -466,13 +447,10 @@ static inline void RemapInstruction(Instruction *I, /// CloneLoop - Recursively clone the specified loop and all of its children, /// mapping the blocks with the specified map. static Loop *CloneLoop(Loop *L, Loop *PL, DenseMap &VM, - LoopInfo *LI) { + LoopInfo *LI, LPPassManager *LPM) { Loop *New = new Loop(); - if (PL) - PL->addChildLoop(New); - else - LI->addTopLevelLoop(New); + LPM->insertLoop(New, PL); // Add all of the blocks in L to the new loop. for (Loop::block_iterator I = L->block_begin(), E = L->block_end(); @@ -482,7 +460,7 @@ static Loop *CloneLoop(Loop *L, Loop *PL, DenseMap &VM, // Add all of the subloops to the new loop. for (Loop::iterator I = L->begin(), E = L->end(); I != E; ++I) - CloneLoop(*I, New, VM, LI); + CloneLoop(*I, New, VM, LI, LPM); return New; } @@ -545,7 +523,7 @@ void LoopUnswitch::UnswitchTrivialCondition(Loop *L, Value *Cond, OrigPH->getTerminator()->eraseFromParent(); // We need to reprocess this loop, it could be unswitched again. - LoopProcessWorklist.push_back(L); + LPM->redoLoop(L); // Now that we know that the loop is never entered when this condition is a // particular value, rewrite the loop with this info. We know that this will @@ -654,7 +632,7 @@ void LoopUnswitch::UnswitchNontrivialCondition(Value *LIC, Constant *Val, NewBlocks[0], F->end()); // Now we create the new Loop object for the versioned loop. - Loop *NewLoop = CloneLoop(L, L->getParentLoop(), ValueMap, LI); + Loop *NewLoop = CloneLoop(L, L->getParentLoop(), ValueMap, LI, LPM); Loop *ParentLoop = L->getParentLoop(); if (ParentLoop) { // Make sure to add the cloned preheader and exit blocks to the parent loop @@ -699,8 +677,8 @@ void LoopUnswitch::UnswitchNontrivialCondition(Value *LIC, Constant *Val, EmitPreheaderBranchOnCondition(LIC, Val, NewBlocks[0], LoopBlocks[0], OldBR); OldBR->eraseFromParent(); - LoopProcessWorklist.push_back(L); LoopProcessWorklist.push_back(NewLoop); + LPM->redoLoop(L); // Now we rewrite the original code to know that the condition is true and the // new code to know that the condition is false. @@ -855,54 +833,7 @@ void LoopUnswitch::RemoveBlockIfDead(BasicBlock *BB, /// so they just reparent loops. If the loops are actually dead, they will be /// removed later. void LoopUnswitch::RemoveLoopFromHierarchy(Loop *L) { - if (Loop *ParentLoop = L->getParentLoop()) { // Not a top-level loop. - // Reparent all of the blocks in this loop. Since BBLoop had a parent, - // they are now all in it. - for (Loop::block_iterator I = L->block_begin(), E = L->block_end(); - I != E; ++I) - if (LI->getLoopFor(*I) == L) // Don't change blocks in subloops. - LI->changeLoopFor(*I, ParentLoop); - - // Remove the loop from its parent loop. - for (Loop::iterator I = ParentLoop->begin(), E = ParentLoop->end();; - ++I) { - assert(I != E && "Couldn't find loop"); - if (*I == L) { - ParentLoop->removeChildLoop(I); - break; - } - } - - // Move all subloops into the parent loop. - while (L->begin() != L->end()) - ParentLoop->addChildLoop(L->removeChildLoop(L->end()-1)); - } else { - // Reparent all of the blocks in this loop. Since BBLoop had no parent, - // they no longer in a loop at all. - - for (unsigned i = 0; i != L->getBlocks().size(); ++i) { - // Don't change blocks in subloops. - if (LI->getLoopFor(L->getBlocks()[i]) == L) { - LI->removeBlock(L->getBlocks()[i]); - --i; - } - } - - // Remove the loop from the top-level LoopInfo object. - for (LoopInfo::iterator I = LI->begin(), E = LI->end();; ++I) { - assert(I != E && "Couldn't find loop"); - if (*I == L) { - LI->removeLoop(I); - break; - } - } - - // Move all of the subloops to the top-level. - while (L->begin() != L->end()) - LI->addTopLevelLoop(L->removeChildLoop(L->end()-1)); - } - - delete L; + LPM->deleteLoopFromQueue(L); RemoveLoopFromWorklist(L); } diff --git a/llvm/tools/opt/opt.cpp b/llvm/tools/opt/opt.cpp index 24dab745c50d..14dd158b906c 100644 --- a/llvm/tools/opt/opt.cpp +++ b/llvm/tools/opt/opt.cpp @@ -18,6 +18,7 @@ #include "llvm/Bytecode/WriteBytecodePass.h" #include "llvm/Assembly/PrintModulePass.h" #include "llvm/Analysis/Verifier.h" +#include "llvm/Analysis/LoopPass.h" #include "llvm/Target/TargetData.h" #include "llvm/Target/TargetMachine.h" #include "llvm/Support/PassNameParser.h"