From: Fariborz Jahanian <fjahanian@apple.com>
Date: Mon, 25 Apr 2011 22:30:02 +0000 (+0000)
Subject: Ir-gen the side-effect(s) when __builtin_expect is
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=ec9919549095390b5737c561544f8bd49fc894de;p=clang

Ir-gen the side-effect(s) when __builtin_expect is
constant-folded. // rdar://9330105


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@130163 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/CGBuiltin.cpp b/lib/CodeGen/CGBuiltin.cpp
index e553eb6c27..2971436831 100644
--- a/lib/CodeGen/CGBuiltin.cpp
+++ b/lib/CodeGen/CGBuiltin.cpp
@@ -177,6 +177,15 @@ RValue CodeGenFunction::EmitBuiltinExpr(const FunctionDecl *FD,
   // See if we can constant fold this builtin.  If so, don't emit it at all.
   Expr::EvalResult Result;
   if (E->Evaluate(Result, CGM.getContext())) {
+    // Short circuiting the __builtin_expect on its 1st argument
+    // must still IR-gen the 1st and 2nd argument's side-effect.
+    if (BuiltinID == Builtin::BI__builtin_expect) {
+      if (E->getArg(0)->HasSideEffects(getContext()))
+        (void)EmitScalarExpr(E->getArg(0));
+      if (E->getArg(1)->HasSideEffects(getContext()))
+        (void)EmitScalarExpr(E->getArg(1));
+    }
+    
     if (Result.Val.isInt())
       return RValue::get(llvm::ConstantInt::get(getLLVMContext(),
                                                 Result.Val.getInt()));
diff --git a/test/CodeGen/builtin-expect.c b/test/CodeGen/builtin-expect.c
index 8f02c4da78..88479d90a0 100644
--- a/test/CodeGen/builtin-expect.c
+++ b/test/CodeGen/builtin-expect.c
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -emit-llvm -o - %s | FileCheck %s
 
 int x;
 int y(void);
@@ -9,3 +9,13 @@ void FUNC() {
     foo ();
 }
 
+// rdar://9330105
+void isigprocmask(void);
+long bar();
+
+int main() {
+    (void) __builtin_expect((isigprocmask(), 0), bar());
+}
+
+// CHECK: call void @isigprocmask()
+// CHECK: [[C:%.*]] = call i64 (...)* @bar()