diff options
| -rw-r--r-- | lib/Target/CppBackend/SimplifyAllocas.cpp | 40 |
1 files changed, 12 insertions, 28 deletions
diff --git a/lib/Target/CppBackend/SimplifyAllocas.cpp b/lib/Target/CppBackend/SimplifyAllocas.cpp index 19480ffe7c..0aca53bc50 100644 --- a/lib/Target/CppBackend/SimplifyAllocas.cpp +++ b/lib/Target/CppBackend/SimplifyAllocas.cpp @@ -35,7 +35,7 @@ namespace llvm { /* * Find cases where an alloca is used only to load and store a single value, * even though it is bitcast. Then replace it with a direct alloca of that - * simple type. + * simple type, and avoid the bitcasts. */ struct SimplifyAllocas : public FunctionPass { @@ -73,35 +73,20 @@ bool SimplifyAllocas::runOnFunction(Function &Func) { std::vector<Instruction*> Aliases; // the bitcasts of this alloca for (Instruction::use_iterator UI = AI->use_begin(), UE = AI->use_end(); UI != UE && !Fail; ++UI) { Instruction *U = dyn_cast<Instruction>(*UI); - if (!U) { Fail = true; break; } - switch (U->getOpcode()) { - case Instruction::Load: { - CHECK_TYPE(U->getType()); + if (!U || U->getOpcode() != Instruction::BitCast) { Fail = true; break; } + // bitcasting just to do loads and stores is ok + for (Instruction::use_iterator BUI = U->use_begin(), BUE = U->use_end(); BUI != BUE && !Fail; ++BUI) { + Instruction *BU = dyn_cast<Instruction>(*BUI); + if (!BU) { Fail = true; break; } + if (BU->getOpcode() == Instruction::Load) { + CHECK_TYPE(BU->getType()); break; } - case Instruction::Store: { - CHECK_TYPE(U->getOperand(0)->getType()); - if (U->getOperand(0) == AI) Fail = true; - break; - } - case Instruction::BitCast: { - // bitcasting just to do loads and stores is ok - for (Instruction::use_iterator BUI = U->use_begin(), BUE = U->use_end(); BUI != BUE && !Fail; ++BUI) { - Instruction *BU = dyn_cast<Instruction>(*BUI); - if (!BU) { Fail = true; break; } - if (BU->getOpcode() == Instruction::Load) { - CHECK_TYPE(BU->getType()); - break; - } - if (BU->getOpcode() != Instruction::Store) { Fail = true; break; } - CHECK_TYPE(BU->getOperand(0)->getType()); - if (BU->getOperand(0) == U) { Fail = true; break; } - } - if (!Fail) Aliases.push_back(U); - break; - } - default: { Fail = true; break; } + if (BU->getOpcode() != Instruction::Store) { Fail = true; break; } + CHECK_TYPE(BU->getOperand(0)->getType()); + if (BU->getOperand(0) == U) { Fail = true; break; } } + if (!Fail) Aliases.push_back(U); } if (!Fail && Aliases.size() > 0) { // success, replace the alloca and the bitcast aliases with a single simple alloca @@ -109,7 +94,6 @@ bool SimplifyAllocas::runOnFunction(Function &Func) { NA->takeName(AI); NA->setAlignment(AI->getAlignment()); NA->setDebugLoc(AI->getDebugLoc()); - AI->replaceAllUsesWith(NA); ToRemove.push_back(AI); for (unsigned i = 0; i < Aliases.size(); i++) { Aliases[i]->replaceAllUsesWith(NA); |