diff --git a/lib/Transforms/Scalar/CodeGenPrepare.cpp b/lib/Transforms/Scalar/CodeGenPrepare.cpp index c15bd8a4268..4f14a479eb4 100644 --- a/lib/Transforms/Scalar/CodeGenPrepare.cpp +++ b/lib/Transforms/Scalar/CodeGenPrepare.cpp @@ -98,6 +98,7 @@ namespace { bool CanMergeBlocks(const BasicBlock *BB, const BasicBlock *DestBB) const; void EliminateMostlyEmptyBlock(BasicBlock *BB); bool OptimizeBlock(BasicBlock &BB); + bool OptimizeInst(Instruction *I); bool OptimizeMemoryInst(Instruction *I, Value *Addr, const Type *AccessTy, DenseMap &SunkAddrs); bool OptimizeInlineAsmInst(Instruction *I, CallSite CS, @@ -959,6 +960,54 @@ bool CodeGenPrepare::OptimizeExtUses(Instruction *I) { return MadeChange; } +bool CodeGenPrepare::OptimizeInst(Instruction *I) { + bool MadeChange = false; + + if (PHINode *P = dyn_cast(I)) { + // It is possible for very late stage optimizations (such as SimplifyCFG) + // to introduce PHI nodes too late to be cleaned up. If we detect such a + // trivial PHI, go ahead and zap it here. + if (Value *V = SimplifyInstruction(P)) { + P->replaceAllUsesWith(V); + P->eraseFromParent(); + ++NumPHIsElim; + } + } else if (CastInst *CI = dyn_cast(I)) { + // If the source of the cast is a constant, then this should have + // already been constant folded. The only reason NOT to constant fold + // it is if something (e.g. LSR) was careful to place the constant + // evaluation in a block other than then one that uses it (e.g. to hoist + // the address of globals out of a loop). If this is the case, we don't + // want to forward-subst the cast. + if (isa(CI->getOperand(0))) + return false; + + bool Change = false; + if (TLI) { + Change = OptimizeNoopCopyExpression(CI, *TLI); + MadeChange |= Change; + } + + if (!Change && (isa(I) || isa(I))) { + MadeChange |= MoveExtToFormExtLoad(I); + MadeChange |= OptimizeExtUses(I); + } + } else if (CmpInst *CI = dyn_cast(I)) { + MadeChange |= OptimizeCmpExpression(CI); + } else if (LoadInst *LI = dyn_cast(I)) { + if (TLI) + MadeChange |= OptimizeMemoryInst(I, I->getOperand(0), LI->getType(), + SunkAddrs); + } else if (StoreInst *SI = dyn_cast(I)) { + if (TLI) + MadeChange |= OptimizeMemoryInst(I, SI->getOperand(1), + SI->getOperand(0)->getType(), + SunkAddrs); + } + + return MadeChange; +} + // In this pass we look for GEP and cast instructions that are used // across basic blocks and rewrite them to improve basic-block-at-a-time // selection. @@ -982,47 +1031,7 @@ bool CodeGenPrepare::OptimizeBlock(BasicBlock &BB) { for (BasicBlock::iterator BBI = BB.begin(), E = BB.end(); BBI != E; ) { Instruction *I = BBI++; - if (PHINode *P = dyn_cast(I)) { - // It is possible for very late stage optimizations (such as SimplifyCFG) - // to introduce PHI nodes too late to be cleaned up. If we detect such a - // trivial PHI, go ahead and zap it here. - if (Value *V = SimplifyInstruction(P)) { - P->replaceAllUsesWith(V); - P->eraseFromParent(); - ++NumPHIsElim; - } - } else if (CastInst *CI = dyn_cast(I)) { - // If the source of the cast is a constant, then this should have - // already been constant folded. The only reason NOT to constant fold - // it is if something (e.g. LSR) was careful to place the constant - // evaluation in a block other than then one that uses it (e.g. to hoist - // the address of globals out of a loop). If this is the case, we don't - // want to forward-subst the cast. - if (isa(CI->getOperand(0))) - continue; - - bool Change = false; - if (TLI) { - Change = OptimizeNoopCopyExpression(CI, *TLI); - MadeChange |= Change; - } - - if (!Change && (isa(I) || isa(I))) { - MadeChange |= MoveExtToFormExtLoad(I); - MadeChange |= OptimizeExtUses(I); - } - } else if (CmpInst *CI = dyn_cast(I)) { - MadeChange |= OptimizeCmpExpression(CI); - } else if (LoadInst *LI = dyn_cast(I)) { - if (TLI) - MadeChange |= OptimizeMemoryInst(I, I->getOperand(0), LI->getType(), - SunkAddrs); - } else if (StoreInst *SI = dyn_cast(I)) { - if (TLI) - MadeChange |= OptimizeMemoryInst(I, SI->getOperand(1), - SI->getOperand(0)->getType(), - SunkAddrs); - } else if (GetElementPtrInst *GEPI = dyn_cast(I)) { + if (GetElementPtrInst *GEPI = dyn_cast(I)) { if (GEPI->hasAllZeroIndices()) { /// The GEP operand must be a pointer, so must its result -> BitCast Instruction *NC = new BitCastInst(GEPI->getOperand(0), GEPI->getType(), @@ -1050,6 +1059,8 @@ bool CodeGenPrepare::OptimizeBlock(BasicBlock &BB) { // enclosing iterator here. MadeChange |= OptimizeCallInst(CI); } + } else { + MadeChange |= OptimizeInst(I); } }