diff --git a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
--- a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
@@ -1562,8 +1562,9 @@
   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_SpecificFP(0.0)) ||
+      match(Expo, m_SpecificFP(-0.0)))
     return ConstantFP::get(Ty, 1.0);
 
   // pow(x, 1.0) -> x
diff --git a/llvm/test/Transforms/InstCombine/pow-0.ll b/llvm/test/Transforms/InstCombine/pow-0.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/pow-0.ll
@@ -0,0 +1,31 @@
+; RUN: opt < %s -instcombine -S | FileCheck %s
+
+; CHECK-LABEL: @zero(
+; CHECK-NEXT:  ret double 1.000000e+00
+define double @zero(double %value) {
+  %res = call double @llvm.pow.f64(double %value, double 0.000000e+00)
+  ret double %res
+}
+
+; CHECK-LABEL: @minus_zero(
+; CHECK-NEXT:  ret double 1.000000e+00
+define double @minus_zero(double %value) {
+  %res = call double @llvm.pow.f64(double %value, double -0.000000e+00)
+  ret double %res
+}
+
+; CHECK-LABEL: @fast_zero(
+; CHECK-NEXT:  ret double 1.000000e+00
+define double @fast_zero(double %value) {
+  %res = call fast double @llvm.pow.f64(double %value, double 0.000000e+00)
+  ret double %res
+}
+
+; CHECK-LABEL: @fast_minus_zero(
+; CHECK-NEXT:  ret double 1.000000e+00
+define double @fast_minus_zero(double %value) {
+  %res = call fast double @llvm.pow.f64(double %value, double -0.000000e+00)
+  ret double %res
+}
+
+declare double @llvm.pow.f64(double, double)