1 files changed, 37 insertions, 0 deletions
diff --git a/test/CodeGen/X86/pr28504.ll b/test/CodeGen/X86/pr28504.ll
new file mode 100644
index 0000000000000..a617c8aa4f1e6
--- /dev/null
+++ b/test/CodeGen/X86/pr28504.ll
@@ -0,0 +1,37 @@
+; RUN: llc -mtriple=x86_64-unknown-linux-gnu < %s | FileCheck %s
+
+; The test case is rather involved, because we need to get to a state where
+; We have a sext(setcc x, y, cc) -> (select (setcc x, y, cc), T, 0) combine,
+; BUT this combine is only triggered post-legalization, so the setcc's return
+; type is i8. So we can't have the combine opportunity be exposed too early.
+; Basically, what we want to see is that the compare result zero-extended, and 
+; then stored. Only one zext, and no sexts.
+
+; CHECK-LABEL: main:
+; CHECK: movzbl (%rdi), %[[EAX:.*]]
+; CHECK-NEXT: xorl  %e[[C:.]]x, %e[[C]]x
+; CHECK-NEXT: cmpl  $1, %[[EAX]]
+; CHECK-NEXT: sete  %[[C]]l
+; CHECK-NEXT: movl  %e[[C]]x, (%rsi)
+define void @main(i8* %p, i32* %q) {
+bb:
+  %tmp4 = load i8, i8* %p, align 1
+  %tmp5 = sext i8 %tmp4 to i32
+  %tmp6 = load i8, i8* %p, align 1
+  %tmp7 = zext i8 %tmp6 to i32
+  %tmp8 = sub nsw i32 %tmp5, %tmp7
+  %tmp11 = icmp eq i32 %tmp7, 1
+  %tmp12 = zext i1 %tmp11 to i32
+  %tmp13 = add nsw i32 %tmp8, %tmp12
+  %tmp14 = trunc i32 %tmp13 to i8
+  %tmp15 = sext i8 %tmp14 to i16
+  %tmp16 = sext i16 %tmp15 to i32
+  store i32 %tmp16, i32* %q, align 4
+  br i1 %tmp11, label %bb21, label %bb22
+
+bb21:                                             ; preds = %bb
+  unreachable
+
+bb22:                                             ; preds = %bb
+  ret void
+}