Index: lib/Transforms/Scalar/PartiallyInlineLibCalls.cpp
===================================================================
--- lib/Transforms/Scalar/PartiallyInlineLibCalls.cpp
+++ lib/Transforms/Scalar/PartiallyInlineLibCalls.cpp
@@ -64,6 +64,7 @@
   // Add attribute "readnone" so that backend can use a native sqrt instruction
   // for this call. Insert a FP compare instruction and a conditional branch
   // at the end of CurrBB.
+  Call->removeAttribute(AttributeList::FunctionIndex, Attribute::WriteOnly);
   Call->addAttribute(AttributeList::FunctionIndex, Attribute::ReadNone);
   CurrBB.getTerminator()->eraseFromParent();
   Builder.SetInsertPoint(&CurrBB);
Index: test/Transforms/PartiallyInlineLibCalls/X86/good-prototype.ll
===================================================================
--- test/Transforms/PartiallyInlineLibCalls/X86/good-prototype.ll
+++ test/Transforms/PartiallyInlineLibCalls/X86/good-prototype.ll
@@ -5,7 +5,7 @@
 define float @f(float %val) {
 ; CHECK-LABEL: @f(
 ; CHECK-NEXT:  entry:
-; CHECK-NEXT:    [[RES:%.*]] = tail call float @sqrtf(float [[VAL:%.*]]) #0
+; CHECK-NEXT:    [[RES:%.*]] = tail call float @sqrtf(float [[VAL:%.*]]) [[RN:#[0-9]+]]
 ; CHECK-NEXT:    [[TMP0:%.*]] = fcmp oge float [[VAL]], 0.000000e+00
 ; CHECK-NEXT:    br i1 [[TMP0]], label [[ENTRY_SPLIT:%.*]], label [[CALL_SQRT:%.*]]
 ; CHECK:       call.sqrt:
@@ -20,4 +20,26 @@
   ret float %res
 }
 
+define float @f2(float %val) {
+; CHECK-LABEL: @f2(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[RES:%.*]] = tail call float @sqrtf(float [[VAL:%.*]]) [[RN]]
+; CHECK-NEXT:    [[TMP0:%.*]] = fcmp oge float [[VAL]], 0.000000e+00
+; CHECK-NEXT:    br i1 [[TMP0]], label [[ENTRY_SPLIT:%.*]], label [[CALL_SQRT:%.*]]
+; CHECK:       call.sqrt:
+; CHECK-NEXT:    [[TMP1:%.*]] = tail call float @sqrtf(float [[VAL]]) [[WO:#[0-9]+]]
+; CHECK-NEXT:    br label [[ENTRY_SPLIT]]
+; CHECK:       entry.split:
+; CHECK-NEXT:    [[TMP2:%.*]] = phi float [ [[RES]], [[ENTRY:%.*]] ], [ [[TMP1]], [[CALL_SQRT]] ]
+; CHECK-NEXT:    ret float [[TMP2]]
+;
+entry:
+  %res = tail call float @sqrtf(float %val) #0
+  ret float %res
+}
+
 declare float @sqrtf(float)
+
+; CHECK: attributes [[RN]] = { readnone }
+; CHECK: attributes [[WO]] = { writeonly }
+attributes #0 = { writeonly }