Index: lib/Analysis/TargetLibraryInfo.cpp
===================================================================
--- lib/Analysis/TargetLibraryInfo.cpp
+++ lib/Analysis/TargetLibraryInfo.cpp
@@ -61,6 +61,13 @@
   }
 #endif // !NDEBUG
 
+  if (T.getArch() == Triple::r600 ||
+      T.getArch() == Triple::amdgcn) {
+    TLI.setUnavailable(LibFunc::ldexp);
+    TLI.setUnavailable(LibFunc::ldexpf);
+    TLI.setUnavailable(LibFunc::ldexpl);
+  }
+
   // There are no library implementations of mempcy and memset for AMD gpus and
   // these can be difficult to lower in the backend.
   if (T.getArch() == Triple::r600 ||
Index: test/Transforms/InstCombine/exp2-1.ll
===================================================================
--- test/Transforms/InstCombine/exp2-1.ll
+++ test/Transforms/InstCombine/exp2-1.ll
@@ -1,7 +1,8 @@
 ; Test that the exp2 library call simplifier works correctly.
 ;
 ; RUN: opt < %s -instcombine -S | FileCheck %s
-; RUN: opt < %s -instcombine -S -mtriple=i386-pc-win32 | FileCheck %s -check-prefix=CHECK-WIN
+; RUN: opt < %s -instcombine -S -mtriple=i386-pc-win32 | FileCheck %s -check-prefix=CHECK-NOLDEXP
+; RUN: opt < %s -instcombine -S -mtriple=amdgcn-unknown-unknown -mcpu=tonga | FileCheck %s -check-prefix=CHECK-NOLDEXP
 
 target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
 
@@ -81,20 +82,20 @@
 
 define double @test_simplify9(i8 zeroext %x) {
 ; CHECK-LABEL: @test_simplify9(
-; CHECK-WIN-LABEL: @test_simplify9(
+; CHECK-NOLDEXP-LABEL: @test_simplify9(
   %conv = uitofp i8 %x to double
   %ret = call double @llvm.exp2.f64(double %conv)
 ; CHECK: call double @ldexp
-; CHECK-WIN: call double @ldexp
+; CHECK-NOLDEXP: call double @ldexp
   ret double %ret
 }
 
 define float @test_simplify10(i8 zeroext %x) {
 ; CHECK-LABEL: @test_simplify10(
-; CHECK-WIN-LABEL: @test_simplify10(
+; CHECK-NOLDEXP-LABEL: @test_simplify10(
   %conv = uitofp i8 %x to float
   %ret = call float @llvm.exp2.f32(float %conv)
 ; CHECK: call float @ldexpf
-; CHECK-WIN-NOT: call float @ldexpf
+; CHECK-NOLDEXP-NOT: call float @ldexpf
   ret float %ret
 }