[SimplifyLibCalls] Enable double to float shrinking for copysign

rdar://19049359

Differential Revision: http://reviews.llvm.org/D6495

llvm-svn: 223269
diff --git a/llvm/test/Transforms/InstCombine/float-shrink-compare.ll b/llvm/test/Transforms/InstCombine/float-shrink-compare.ll
index e500467..ef1221b 100644
--- a/llvm/test/Transforms/InstCombine/float-shrink-compare.ll
+++ b/llvm/test/Transforms/InstCombine/float-shrink-compare.ll
@@ -222,8 +222,22 @@
 ; CHECK-NEXT: fcmp oeq float %fmaxf, %z
 }
 
+define i32 @test19(float %x, float %y, float %z) nounwind uwtable {
+  %1 = fpext float %x to double
+  %2 = fpext float %y to double
+  %3 = call double @copysign(double %1, double %2) nounwind
+  %4 = fpext float %z to double
+  %5 = fcmp oeq double %3, %4
+  %6 = zext i1 %5 to i32
+  ret i32 %6
+; CHECK-LABEL: @test19(
+; CHECK-NEXT: %copysignf = call float @copysignf(float %x, float %y)
+; CHECK-NEXT: fcmp oeq float %copysignf, %z
+}
+
 declare double @fabs(double) nounwind readnone
 declare double @ceil(double) nounwind readnone
+declare double @copysign(double, double) nounwind readnone
 declare double @floor(double) nounwind readnone
 declare double @nearbyint(double) nounwind readnone
 declare double @rint(double) nounwind readnone