diff options
Diffstat (limited to 'lib/Transforms/InstCombine/InstructionCombining.cpp')
| -rw-r--r-- | lib/Transforms/InstCombine/InstructionCombining.cpp | 20 |
1 files changed, 13 insertions, 7 deletions
diff --git a/lib/Transforms/InstCombine/InstructionCombining.cpp b/lib/Transforms/InstCombine/InstructionCombining.cpp index 9a52874c4c212..27fc34d231752 100644 --- a/lib/Transforms/InstCombine/InstructionCombining.cpp +++ b/lib/Transforms/InstCombine/InstructionCombining.cpp @@ -770,10 +770,6 @@ static Value *foldOperationIntoSelectOperand(Instruction &I, Value *SO, return RI; } -/// Given an instruction with a select as one operand and a constant as the -/// other operand, try to fold the binary operator into the select arguments. -/// This also works for Cast instructions, which obviously do not have a second -/// operand. Instruction *InstCombiner::FoldOpIntoSelect(Instruction &Op, SelectInst *SI) { // Don't modify shared select instructions. if (!SI->hasOneUse()) @@ -824,9 +820,6 @@ Instruction *InstCombiner::FoldOpIntoSelect(Instruction &Op, SelectInst *SI) { return SelectInst::Create(SI->getCondition(), NewTV, NewFV, "", nullptr, SI); } -/// Given a binary operator, cast instruction, or select which has a PHI node as -/// operand #0, see if we can fold the instruction into the PHI (which is only -/// possible if all operands to the PHI are constants). Instruction *InstCombiner::FoldOpIntoPhi(Instruction &I) { PHINode *PN = cast<PHINode>(I.getOperand(0)); unsigned NumPHIValues = PN->getNumIncomingValues(); @@ -964,6 +957,19 @@ Instruction *InstCombiner::FoldOpIntoPhi(Instruction &I) { return replaceInstUsesWith(I, NewPN); } +Instruction *InstCombiner::foldOpWithConstantIntoOperand(Instruction &I) { + assert(isa<Constant>(I.getOperand(1)) && "Unexpected operand type"); + + if (auto *Sel = dyn_cast<SelectInst>(I.getOperand(0))) { + if (Instruction *NewSel = FoldOpIntoSelect(I, Sel)) + return NewSel; + } else if (isa<PHINode>(I.getOperand(0))) { + if (Instruction *NewPhi = FoldOpIntoPhi(I)) + return NewPhi; + } + return nullptr; +} + /// Given a pointer type and a constant offset, determine whether or not there /// is a sequence of GEP indices into the pointed type that will land us at the /// specified offset. If so, fill them into NewIndices and return the resultant |