[llvm] r371221 - [SimplifyLibCalls] handle pow(x, -0.0) before it can assert (PR43233)

[Sanjay Patel via llvm-commits]

Author: spatel
Date: Fri Sep  6 09:10:18 2019
New Revision: 371221

URL: http://llvm.org/viewvc/llvm-project?rev=371221&view=rev
Log:
[SimplifyLibCalls] handle pow(x,-0.0) before it can assert (PR43233)

https://bugs.llvm.org/show_bug.cgi?id=43233

Modified:
    llvm/trunk/lib/Transforms/Utils/SimplifyLibCalls.cpp
    llvm/trunk/test/Transforms/InstCombine/pow-4.ll

Modified: llvm/trunk/lib/Transforms/Utils/SimplifyLibCalls.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/SimplifyLibCalls.cpp?rev=371221&r1=371220&r2=371221&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/SimplifyLibCalls.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/SimplifyLibCalls.cpp Fri Sep  6 09:10:18 2019
@@ -1562,8 +1562,8 @@ Value *LibCallSimplifier::optimizePow(Ca
   if (match(Expo, m_SpecificFP(-1.0)))
     return B.CreateFDiv(ConstantFP::get(Ty, 1.0), Base, "reciprocal");
 
-  // pow(x, 0.0) -> 1.0
-  if (match(Expo, m_SpecificFP(0.0)))
+  // pow(x, +/-0.0) -> 1.0
+  if (match(Expo, m_AnyZeroFP()))
     return ConstantFP::get(Ty, 1.0);
 
   // pow(x, 1.0) -> x

Modified: llvm/trunk/test/Transforms/InstCombine/pow-4.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/pow-4.ll?rev=371221&r1=371220&r2=371221&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/pow-4.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/pow-4.ll Fri Sep  6 09:10:18 2019
@@ -223,3 +223,13 @@ define <4 x float> @test_simplify_3_5(<4
   ret <4 x float> %1
 }
 
+; Make sure that -0.0 exponent is always simplified.
+
+define double @PR43233(double %x) {
+; CHECK-LABEL: @PR43233(
+; CHECK-NEXT:    ret double 1.000000e+00
+;
+  %r = call fast double @llvm.pow.f64(double %x, double -0.0)
+  ret double %r
+}
+