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Diffstat (limited to 'lib/Transforms/Scalar/GEPSplitter.cpp')
-rw-r--r-- | lib/Transforms/Scalar/GEPSplitter.cpp | 83 |
1 files changed, 0 insertions, 83 deletions
diff --git a/lib/Transforms/Scalar/GEPSplitter.cpp b/lib/Transforms/Scalar/GEPSplitter.cpp deleted file mode 100644 index 4c3d188..0000000 --- a/lib/Transforms/Scalar/GEPSplitter.cpp +++ /dev/null @@ -1,83 +0,0 @@ -//===- GEPSplitter.cpp - Split complex GEPs into simple ones --------------===// -// -// The LLVM Compiler Infrastructure -// -// This file is distributed under the University of Illinois Open Source -// License. See LICENSE.TXT for details. -// -//===----------------------------------------------------------------------===// -// -// This function breaks GEPs with more than 2 non-zero operands into smaller -// GEPs each with no more than 2 non-zero operands. This exposes redundancy -// between GEPs with common initial operand sequences. -// -//===----------------------------------------------------------------------===// - -#define DEBUG_TYPE "split-geps" -#include "llvm/Transforms/Scalar.h" -#include "llvm/Constants.h" -#include "llvm/Function.h" -#include "llvm/Instructions.h" -#include "llvm/Pass.h" -using namespace llvm; - -namespace { - class GEPSplitter : public FunctionPass { - virtual bool runOnFunction(Function &F); - virtual void getAnalysisUsage(AnalysisUsage &AU) const; - public: - static char ID; // Pass identification, replacement for typeid - explicit GEPSplitter() : FunctionPass(ID) { - initializeGEPSplitterPass(*PassRegistry::getPassRegistry()); - } - }; -} - -char GEPSplitter::ID = 0; -INITIALIZE_PASS(GEPSplitter, "split-geps", - "split complex GEPs into simple GEPs", false, false) - -FunctionPass *llvm::createGEPSplitterPass() { - return new GEPSplitter(); -} - -bool GEPSplitter::runOnFunction(Function &F) { - bool Changed = false; - - // Visit each GEP instruction. - for (Function::iterator I = F.begin(), E = F.end(); I != E; ++I) - for (BasicBlock::iterator II = I->begin(), IE = I->end(); II != IE; ) - if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(II++)) { - unsigned NumOps = GEP->getNumOperands(); - // Ignore GEPs which are already simple. - if (NumOps <= 2) - continue; - bool FirstIndexIsZero = isa<ConstantInt>(GEP->getOperand(1)) && - cast<ConstantInt>(GEP->getOperand(1))->isZero(); - if (NumOps == 3 && FirstIndexIsZero) - continue; - // The first index is special and gets expanded with a 2-operand GEP - // (unless it's zero, in which case we can skip this). - Value *NewGEP = FirstIndexIsZero ? - GEP->getOperand(0) : - GetElementPtrInst::Create(GEP->getOperand(0), GEP->getOperand(1), - "tmp", GEP); - // All remaining indices get expanded with a 3-operand GEP with zero - // as the second operand. - Value *Idxs[2]; - Idxs[0] = ConstantInt::get(Type::getInt64Ty(F.getContext()), 0); - for (unsigned i = 2; i != NumOps; ++i) { - Idxs[1] = GEP->getOperand(i); - NewGEP = GetElementPtrInst::Create(NewGEP, Idxs, Idxs+2, "tmp", GEP); - } - GEP->replaceAllUsesWith(NewGEP); - GEP->eraseFromParent(); - Changed = true; - } - - return Changed; -} - -void GEPSplitter::getAnalysisUsage(AnalysisUsage &AU) const { - AU.setPreservesCFG(); -} |