diff options
Diffstat (limited to 'llvm/lib')
3 files changed, 7 insertions, 47 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp index 482768655bd..223bba03507 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp @@ -3970,19 +3970,6 @@ Instruction *InstCombiner::visitFCmpInst(FCmpInst &I) { } } - // Test if the FCmpInst instruction is used exclusively by a select as - // part of a minimum or maximum operation. If so, refrain from doing - // any other folding. This helps out other analyses which understand - // non-obfuscated minimum and maximum idioms, such as ScalarEvolution - // and CodeGen. And in this case, at least one of the comparison - // operands has at least one user besides the compare (the select), - // which would often largely negate the benefit of folding anyway. - if (I.hasOneUse()) - if (SelectInst *SI = dyn_cast<SelectInst>(*I.user_begin())) - if ((SI->getOperand(1) == Op0 && SI->getOperand(2) == Op1) || - (SI->getOperand(2) == Op0 && SI->getOperand(1) == Op1)) - return nullptr; - // Handle fcmp with constant RHS if (Constant *RHSC = dyn_cast<Constant>(Op1)) { if (Instruction *LHSI = dyn_cast<Instruction>(Op0)) diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp index d2fbcdd3991..b13d3edb9ad 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp @@ -1154,30 +1154,18 @@ Instruction *InstCombiner::visitSelectInst(SelectInst &SI) { } // See if we can fold the select into one of our operands. - if (SI.getType()->isIntOrIntVectorTy()) { + if (SI.getType()->isIntegerTy()) { if (Instruction *FoldI = FoldSelectIntoOp(SI, TrueVal, FalseVal)) return FoldI; Value *LHS, *RHS, *LHS2, *RHS2; - Instruction::CastOps CastOp; - SelectPatternFlavor SPF = matchSelectPattern(&SI, LHS, RHS, &CastOp); + SelectPatternFlavor SPF = matchSelectPattern(&SI, LHS, RHS); + // MAX(MAX(a, b), a) -> MAX(a, b) + // MIN(MIN(a, b), a) -> MIN(a, b) + // MAX(MIN(a, b), a) -> a + // MIN(MAX(a, b), a) -> a if (SPF) { - // Canonicalize so that type casts are outside select patterns. - if (LHS->getType()->getPrimitiveSizeInBits() != - SI.getType()->getPrimitiveSizeInBits()) { - CmpInst::Predicate Pred = getICmpPredicateForMinMax(SPF); - Value *Cmp = Builder->CreateICmp(Pred, LHS, RHS); - Value *NewSI = Builder->CreateCast(CastOp, - Builder->CreateSelect(Cmp, LHS, RHS), - SI.getType()); - return ReplaceInstUsesWith(SI, NewSI); - } - - // MAX(MAX(a, b), a) -> MAX(a, b) - // MIN(MIN(a, b), a) -> MIN(a, b) - // MAX(MIN(a, b), a) -> a - // MIN(MAX(a, b), a) -> a if (SelectPatternFlavor SPF2 = matchSelectPattern(LHS, LHS2, RHS2)) if (Instruction *R = FoldSPFofSPF(cast<Instruction>(LHS),SPF2,LHS2,RHS2, SI, SPF, RHS)) diff --git a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp index b0604534150..53ab81dbef2 100644 --- a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp +++ b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp @@ -714,22 +714,6 @@ Instruction *InstCombiner::FoldOpIntoSelect(Instruction &Op, SelectInst *SI) { return nullptr; } - // Test if a CmpInst instruction is used exclusively by a select as - // part of a minimum or maximum operation. If so, refrain from doing - // any other folding. This helps out other analyses which understand - // non-obfuscated minimum and maximum idioms, such as ScalarEvolution - // and CodeGen. And in this case, at least one of the comparison - // operands has at least one user besides the compare (the select), - // which would often largely negate the benefit of folding anyway. - if (auto *CI = dyn_cast<CmpInst>(SI->getCondition())) { - if (CI->hasOneUse()) { - Value *Op0 = CI->getOperand(0), *Op1 = CI->getOperand(1); - if ((SI->getOperand(1) == Op0 && SI->getOperand(2) == Op1) || - (SI->getOperand(2) == Op0 && SI->getOperand(1) == Op1)) - return nullptr; - } - } - Value *SelectTrueVal = FoldOperationIntoSelectOperand(Op, TV, this); Value *SelectFalseVal = FoldOperationIntoSelectOperand(Op, FV, this); @@ -739,6 +723,7 @@ Instruction *InstCombiner::FoldOpIntoSelect(Instruction &Op, SelectInst *SI) { return nullptr; } + /// FoldOpIntoPhi - 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). |
