Fix builin_expect lowering bug

PR33346

Skip cases when expected value is not constant int.

llvm-svn: 304933

2 files changed, 25 insertions, 1 deletions

diff --git a/llvm/lib/Transforms/Scalar/LowerExpectIntrinsic.cpp b/llvm/lib/Transforms/Scalar/LowerExpectIntrinsic.cpp
index 7d8da9b453f..46f8a356426 100644
--- a/llvm/lib/Transforms/Scalar/LowerExpectIntrinsic.cpp
+++ b/llvm/lib/Transforms/Scalar/LowerExpectIntrinsic.cpp
@@ -93,7 +93,9 @@ static bool handleSwitchExpect(SwitchInst &SI) {
 /// the branch probability info for the originating branch can be inferred.
 static void handlePhiDef(CallInst *Expect) {
   Value &Arg = *Expect->getArgOperand(0);
-  ConstantInt *ExpectedValue = cast<ConstantInt>(Expect->getArgOperand(1));
+  ConstantInt *ExpectedValue = dyn_cast<ConstantInt>(Expect->getArgOperand(1));
+  if (!ExpectedValue)
+    return;
   const APInt &ExpectedPhiValue = ExpectedValue->getValue();
 
   // Walk up in backward a list of instructions that
diff --git a/llvm/test/Transforms/LowerExpectIntrinsic/PR33346.ll b/llvm/test/Transforms/LowerExpectIntrinsic/PR33346.ll
new file mode 100644
index 00000000000..ca962fbdc8f
--- /dev/null
+++ b/llvm/test/Transforms/LowerExpectIntrinsic/PR33346.ll
@@ -0,0 +1,22 @@
+; RUN: opt -lower-expect -S < %s
+; RUN: opt -passes='function(lower-expect)' -S < %s
+
+define i64 @foo(i64 %arg) #0 {
+bb:
+  %tmp = alloca i64, align 8
+  store i64 %arg, i64* %tmp, align 8
+  %tmp1 = load i64, i64* %tmp, align 8
+  %tmp2 = load i64, i64* %tmp, align 8
+  %tmp3 = call i64 @llvm.expect.i64(i64 %tmp1, i64 %tmp2)
+  ret i64 %tmp3
+}
+
+; Function Attrs: nounwind readnone
+declare i64 @llvm.expect.i64(i64, i64)
+
+
+!llvm.module.flags = !{!0}
+!llvm.ident = !{!1}
+
+!0 = !{i32 1, !"wchar_size", i32 4}
+!1 = !{!"clang version 5.0.0 (trunk 304723)"}