diff options
| -rw-r--r-- | llvm/lib/Analysis/InstructionSimplify.cpp | 6 | ||||
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp | 4 | ||||
| -rw-r--r-- | llvm/test/Transforms/InstCombine/fmul.ll | 11 | ||||
| -rw-r--r-- | llvm/test/Transforms/InstSimplify/fast-math.ll | 15 |
4 files changed, 21 insertions, 15 deletions
diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp index a424e693842..eee6d531643 100644 --- a/llvm/lib/Analysis/InstructionSimplify.cpp +++ b/llvm/lib/Analysis/InstructionSimplify.cpp @@ -4251,6 +4251,12 @@ static Value *SimplifyFMulInst(Value *Op0, Value *Op1, FastMathFlags FMF, if (FMF.noNaNs() && FMF.noSignedZeros() && match(Op1, m_AnyZero())) return Op1; + // sqrt(X) * sqrt(X) --> X + Value *X; + if (FMF.isFast() && Op0 == Op1 && + match(Op0, m_Intrinsic<Intrinsic::sqrt>(m_Value(X)))) + return X; + return nullptr; } diff --git a/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp b/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp index d5456cc532f..48fba0319fd 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp @@ -620,10 +620,6 @@ Instruction *InstCombiner::visitFMul(BinaryOperator &I) { if (Op0 == Op1) { if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(Op0)) { - // sqrt(X) * sqrt(X) -> X - if (AllowReassociate && II->getIntrinsicID() == Intrinsic::sqrt) - return replaceInstUsesWith(I, II->getOperand(0)); - // fabs(X) * fabs(X) -> X * X if (II->getIntrinsicID() == Intrinsic::fabs) { Instruction *FMulVal = BinaryOperator::CreateFMul(II->getOperand(0), diff --git a/llvm/test/Transforms/InstCombine/fmul.ll b/llvm/test/Transforms/InstCombine/fmul.ll index 1c05475ba07..2eaa7c3e761 100644 --- a/llvm/test/Transforms/InstCombine/fmul.ll +++ b/llvm/test/Transforms/InstCombine/fmul.ll @@ -172,19 +172,8 @@ define float @test11(float %x, float %y) { ret float %c } -; PR21126: http://llvm.org/bugs/show_bug.cgi?id=21126 -; With unsafe/fast math, sqrt(X) * sqrt(X) is just X. declare double @llvm.sqrt.f64(double) -define double @sqrt_squared1(double %f) { -; CHECK-LABEL: @sqrt_squared1( -; CHECK-NEXT: ret double [[F:%.*]] -; - %sqrt = call double @llvm.sqrt.f64(double %f) - %mul = fmul fast double %sqrt, %sqrt - ret double %mul -} - ; With unsafe/fast math, sqrt(X) * sqrt(X) is just X, ; but make sure another use of the sqrt is intact. ; Note that the remaining fmul is altered but is not 'fast' diff --git a/llvm/test/Transforms/InstSimplify/fast-math.ll b/llvm/test/Transforms/InstSimplify/fast-math.ll index f4f31236e5c..dbf17a2fcee 100644 --- a/llvm/test/Transforms/InstSimplify/fast-math.ll +++ b/llvm/test/Transforms/InstSimplify/fast-math.ll @@ -203,3 +203,18 @@ define float @fdiv_neg_swapped2(float %f) { %div = fdiv nnan float %f, %neg ret float %div } + +; PR21126: http://llvm.org/bugs/show_bug.cgi?id=21126 +; With unsafe/fast math, sqrt(X) * sqrt(X) is just X. + +declare double @llvm.sqrt.f64(double) + +define double @sqrt_squared(double %f) { +; CHECK-LABEL: @sqrt_squared( +; CHECK-NEXT: ret double [[F:%.*]] +; + %sqrt = call double @llvm.sqrt.f64(double %f) + %mul = fmul fast double %sqrt, %sqrt + ret double %mul +} + |
