diff options
| -rw-r--r-- | lib/Transforms/InstCombine/InstCombineCompares.cpp | 25 | ||||
| -rw-r--r-- | test/Transforms/InstCombine/select-select.ll | 24 |
2 files changed, 24 insertions, 25 deletions
diff --git a/lib/Transforms/InstCombine/InstCombineCompares.cpp b/lib/Transforms/InstCombine/InstCombineCompares.cpp index 5dd3325a0b..281ff4050c 100644 --- a/lib/Transforms/InstCombine/InstCombineCompares.cpp +++ b/lib/Transforms/InstCombine/InstCombineCompares.cpp @@ -3313,31 +3313,6 @@ Instruction *InstCombiner::visitFCmpInst(FCmpInst &I) { if (Instruction *NV = FoldFCmp_IntToFP_Cst(I, LHSI, RHSC)) return NV; break; - case Instruction::Select: { - // If either operand of the select is a constant, we can fold the - // comparison into the select arms, which will cause one to be - // constant folded and the select turned into a bitwise or. - Value *Op1 = 0, *Op2 = 0; - if (LHSI->hasOneUse()) { - if (Constant *C = dyn_cast<Constant>(LHSI->getOperand(1))) { - // Fold the known value into the constant operand. - Op1 = ConstantExpr::getCompare(I.getPredicate(), C, RHSC); - // Insert a new FCmp of the other select operand. - Op2 = Builder->CreateFCmp(I.getPredicate(), - LHSI->getOperand(2), RHSC, I.getName()); - } else if (Constant *C = dyn_cast<Constant>(LHSI->getOperand(2))) { - // Fold the known value into the constant operand. - Op2 = ConstantExpr::getCompare(I.getPredicate(), C, RHSC); - // Insert a new FCmp of the other select operand. - Op1 = Builder->CreateFCmp(I.getPredicate(), LHSI->getOperand(1), - RHSC, I.getName()); - } - } - - if (Op1) - return SelectInst::Create(LHSI->getOperand(0), Op1, Op2); - break; - } case Instruction::FSub: { // fcmp pred (fneg x), C -> fcmp swap(pred) x, -C Value *Op; diff --git a/test/Transforms/InstCombine/select-select.ll b/test/Transforms/InstCombine/select-select.ll new file mode 100644 index 0000000000..65820acf07 --- /dev/null +++ b/test/Transforms/InstCombine/select-select.ll @@ -0,0 +1,24 @@ +; RUN: opt -instcombine -S < %s | FileCheck %s + +; CHECK: @foo1 +define float @foo1(float %a) #0 { +; CHECK-NOT: xor + %b = fcmp ogt float %a, 0.000000e+00 + %c = select i1 %b, float %a, float 0.000000e+00 + %d = fcmp olt float %c, 1.000000e+00 + %f = select i1 %d, float %c, float 1.000000e+00 + ret float %f +} + +; CHECK: @foo2 +define float @foo2(float %a) #0 { +; CHECK-NOT: xor + %b = fcmp ogt float %a, 0.000000e+00 + %c = select i1 %b, float %a, float 0.000000e+00 + %d = fcmp olt float %c, 1.000000e+00 + %e = select i1 %b, float %a, float 0.000000e+00 + %f = select i1 %d, float %e, float 1.000000e+00 + ret float %f +} + +attributes #0 = { nounwind readnone ssp uwtable } |