diff options
Diffstat (limited to 'contrib/llvm-project/llvm/lib/Analysis/PHITransAddr.cpp')
| -rw-r--r-- | contrib/llvm-project/llvm/lib/Analysis/PHITransAddr.cpp | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/contrib/llvm-project/llvm/lib/Analysis/PHITransAddr.cpp b/contrib/llvm-project/llvm/lib/Analysis/PHITransAddr.cpp index 7571bd0059cc..5b0fbca23891 100644 --- a/contrib/llvm-project/llvm/lib/Analysis/PHITransAddr.cpp +++ b/contrib/llvm-project/llvm/lib/Analysis/PHITransAddr.cpp @@ -21,6 +21,10 @@ #include "llvm/Support/raw_ostream.h" using namespace llvm; +static cl::opt<bool> EnableAddPhiTranslation( + "gvn-add-phi-translation", cl::init(false), cl::Hidden, + cl::desc("Enable phi-translation of add instructions")); + static bool CanPHITrans(Instruction *Inst) { if (isa<PHINode>(Inst) || isa<GetElementPtrInst>(Inst)) @@ -410,14 +414,14 @@ InsertPHITranslatedSubExpr(Value *InVal, BasicBlock *CurBB, return Result; } -#if 0 - // FIXME: This code works, but it is unclear that we actually want to insert - // a big chain of computation in order to make a value available in a block. - // This needs to be evaluated carefully to consider its cost trade offs. - // Handle add with a constant RHS. - if (Inst->getOpcode() == Instruction::Add && + if (EnableAddPhiTranslation && Inst->getOpcode() == Instruction::Add && isa<ConstantInt>(Inst->getOperand(1))) { + + // FIXME: This code works, but it is unclear that we actually want to insert + // a big chain of computation in order to make a value available in a block. + // This needs to be evaluated carefully to consider its cost trade offs. + // PHI translate the LHS. Value *OpVal = InsertPHITranslatedSubExpr(Inst->getOperand(0), CurBB, PredBB, DT, NewInsts); @@ -431,7 +435,6 @@ InsertPHITranslatedSubExpr(Value *InVal, BasicBlock *CurBB, NewInsts.push_back(Res); return Res; } -#endif return nullptr; } |