Check to see if the 'no-builtin' attribute is set before simplifying a library call.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175470 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 26 insertions, 0 deletions

diff --git a/lib/Transforms/Utils/SimplifyLibCalls.cpp b/lib/Transforms/Utils/SimplifyLibCalls.cpp
index cccf0a67a6..2f47174ea6 100644
--- a/lib/Transforms/Utils/SimplifyLibCalls.cpp
+++ b/lib/Transforms/Utils/SimplifyLibCalls.cpp
@@ -1889,6 +1889,9 @@ LibCallSimplifier::~LibCallSimplifier() {
 }
 
 Value *LibCallSimplifier::optimizeCall(CallInst *CI) {
+  Function *F = CI->getParent()->getParent();
+  // We don't want to "optimize" if the function doesn't want builtins.
+  if (F->hasFnAttribute("no-builtin")) return 0;
   return Impl->optimizeCall(CI);
 }
 
diff --git a/test/Transforms/InstCombine/no-builtin.ll b/test/Transforms/InstCombine/no-builtin.ll
new file mode 100644
index 0000000000..a576cd4813
--- /dev/null
+++ b/test/Transforms/InstCombine/no-builtin.ll
@@ -0,0 +1,23 @@
+; RUN: opt < %s -instcombine -S | FileCheck %s
+@.str = private unnamed_addr constant [14 x i8] c"hello world!\0A\00", align 1
+
+; CHECK: @foo
+; CHECK: printf
+define void @foo() nounwind ssp uwtable "no-builtin" {
+entry:
+  %call = call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([14 x i8]* @.str, i32 0, i32 0))
+  ret void
+}
+
+; CHECK: @bar
+; CHECK: puts
+define void @bar() nounwind ssp uwtable {
+entry:
+  %call = call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([14 x i8]* @.str, i32 0, i32 0))
+  ret void
+}
+
+declare i32 @printf(i8*, ...)
+
+attributes #0 = { nounwind ssp uwtable "no-builtin" }
+attributes #1 = { nounwind ssp uwtable }