Index: lib/Transforms/Utils/SimplifyLibCalls.cpp
===================================================================
--- lib/Transforms/Utils/SimplifyLibCalls.cpp
+++ lib/Transforms/Utils/SimplifyLibCalls.cpp
@@ -1529,10 +1529,6 @@
   bool AllowApprox = Pow->hasApproxFunc();
   bool Ignored;
 
-  // Bail out if simplifying libcalls to pow() is disabled.
-  if (!hasFloatFn(TLI, Ty, LibFunc_pow, LibFunc_powf, LibFunc_powl))
-    return nullptr;
-
   // Propagate the math semantics from the call to any created instructions.
   IRBuilder<>::FastMathFlagGuard Guard(B);
   B.setFastMathFlags(Pow->getFastMathFlags());
@@ -1573,6 +1569,8 @@
   if (Value *Sqrt = replacePowWithSqrt(Pow, B))
     return Sqrt;
 
+  bool HasLibPow = hasFloatFn(TLI, Ty, LibFunc_pow, LibFunc_powf, LibFunc_powl);
+
   // pow(x, n) -> x * x * x * ...
   const APFloat *ExpoF;
   if (AllowApprox && match(Expo, m_APFloat(ExpoF))) {
@@ -1608,6 +1606,10 @@
       InnerChain[1] = Base;
       InnerChain[2] = B.CreateFMul(Base, Base, "square");
 
+      // Bail out if simplifying libcalls to pow() is disabled.
+      if (!HasLibPow)
+        return nullptr;
+
       // We cannot readily convert a non-double type (like float) to a double.
       // So we first convert it to something which could be converted to double.
       ExpoA.convert(APFloat::IEEEdouble(), APFloat::rmTowardZero, &Ignored);
@@ -1624,6 +1626,10 @@
       return FMul;
     }
 
+    // Bail out if simplifying libcalls to pow() is disabled.
+    if (!HasLibPow)
+      return nullptr;
+
     APSInt IntExpo(32, /*isUnsigned=*/false);
     // powf(x, n) -> powi(x, n) if n is a constant signed integer value
     if (ExpoF->isInteger() &&
@@ -1634,6 +1640,10 @@
     }
   }
 
+  // Bail out if simplifying libcalls to pow() is disabled.
+  if (!HasLibPow)
+    return nullptr;
+
   // powf(x, itofp(y)) -> powi(x, y)
   if (AllowApprox && (isa<SIToFPInst>(Expo) || isa<UIToFPInst>(Expo))) {
     if (Value *ExpoI = getIntToFPVal(Expo, B))
Index: test/Transforms/InstCombine/pow-amdgcn.ll
===================================================================
--- /dev/null
+++ test/Transforms/InstCombine/pow-amdgcn.ll
@@ -0,0 +1,55 @@
+; RUN: opt < %s -mtriple=amdgcn-- -targetlibinfo -instcombine -S | FileCheck %s
+
+; Check that a transform of llvm.pow to multiplies or divides happens for amdgcn (for which
+; TLI says no lib functions).
+
+define float @pow_of_1(float %x) {
+; CHECK-LABEL: @pow_of_1(
+; CHECK-NEXT: ret float
+;
+  %pow = call float @llvm.pow.f32(float 1.0, float %x)
+  ret float %pow
+}
+
+define float @pow_minus_1(float %x) {
+; CHECK-LABEL: @pow_minus_1(
+; CHECK: = fdiv float
+;
+  %pow = call float @llvm.pow.f32(float %x, float -1.0)
+  ret float %pow
+}
+
+define float @pow_0(float %x) {
+; CHECK-LABEL: @pow_0(
+; CHECK-NEXT: ret float
+;
+  %pow = call float @llvm.pow.f32(float %x, float 0.0)
+  ret float %pow
+}
+
+define float @pow_1(float %x) {
+; CHECK-LABEL: @pow_1(
+; CHECK-NEXT: ret float
+;
+  %pow = call float @llvm.pow.f32(float %x, float 1.0)
+  ret float %pow
+}
+
+define float @pow_half(float %x) {
+; CHECK-LABEL: @pow_half(
+; CHECK: @llvm.sqrt
+;
+  %pow = call float @llvm.pow.f32(float %x, float 0.5)
+  ret float %pow
+}
+
+define float @pow_2(float %x) {
+; CHECK-LABEL: @pow_2(
+; CHECK: = fmul float
+;
+  %pow = call float @llvm.pow.f32(float %x, float 2.0)
+  ret float %pow
+}
+
+declare float @llvm.pow.f32(float, float)
+