Optimize exact sdiv by a constant power of 2 to ashr.

llvm-svn: 78714

1 files changed, 15 insertions, 0 deletions

diff --git a/llvm/test/Transforms/InstCombine/exact-sdiv.ll b/llvm/test/Transforms/InstCombine/exact-sdiv.ll
new file mode 100644
index 00000000000..9ed524f8ec7
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/exact-sdiv.ll
@@ -0,0 +1,15 @@
+; RUN: llvm-as < %s | opt -instcombine | llvm-dis | FileCheck %s
+
+; CHECK: define i32 @foo
+; CHECK: sdiv i32 %x, 8
+define i32 @foo(i32 %x) {
+  %y = sdiv i32 %x, 8
+  ret i32 %y
+}
+
+; CHECK: define i32 @bar
+; CHECK: ashr i32 %x, 3
+define i32 @bar(i32 %x) {
+  %y = sdiv exact i32 %x, 8
+  ret i32 %y
+}