Fix reassociate to clear optional flags, such as nsw.

llvm-svn: 124712

1 files changed, 22 insertions, 0 deletions

diff --git a/llvm/test/Transforms/Reassociate/optional-flags.ll b/llvm/test/Transforms/Reassociate/optional-flags.ll
new file mode 100644
index 00000000000..5ecc7675f8e
--- /dev/null
+++ b/llvm/test/Transforms/Reassociate/optional-flags.ll
@@ -0,0 +1,22 @@
+; RUN: opt -S -reassociate < %s | FileCheck %s
+; rdar://8944681
+
+; Reassociate should clear optional flags like nsw when reassociating.
+
+; CHECK: @test0
+; CHECK: %y = add i64 %b, %a
+; CHECK: %z = add i64 %y, %c
+define i64 @test0(i64 %a, i64 %b, i64 %c) {
+  %y = add nsw i64 %c, %b
+  %z = add i64 %y, %a
+  ret i64 %z
+}
+
+; CHECK: @test1
+; CHECK: %y = add i64 %b, %a
+; CHECK: %z = add i64 %y, %c
+define i64 @test1(i64 %a, i64 %b, i64 %c) {
+  %y = add i64 %c, %b
+  %z = add nsw i64 %y, %a
+  ret i64 %z
+}