teach instsimplify to transform (X / Y) * Y to X
when the div is an exact udiv.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124994 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Transforms/InstSimplify/reassociate.ll b/test/Transforms/InstSimplify/reassociate.ll
index 928442a..3c8169e 100644
--- a/test/Transforms/InstSimplify/reassociate.ll
+++ b/test/Transforms/InstSimplify/reassociate.ll
@@ -137,6 +137,7 @@
; CHECK: ret i32 %x
}
+
define i32 @udiv1(i32 %x, i32 %y) {
; CHECK: @udiv1
; (no overflow X * Y) / Y -> X
@@ -164,3 +165,22 @@
ret i32 %div
; CHECK: ret i32 0
}
+
+define i32 @udiv4(i32 %x, i32 %y) {
+; CHECK: @udiv4
+; (X / Y) * Y -> X if the division is exact
+ %div = udiv exact i32 %x, %y
+ %mul = mul i32 %div, %y
+ ret i32 %mul
+; CHECK: ret i32 %x
+}
+
+define i32 @udiv5(i32 %x, i32 %y) {
+; CHECK: @udiv5
+; Y * (X / Y) -> X if the division is exact
+ %div = udiv exact i32 %x, %y
+ %mul = mul i32 %y, %div
+ ret i32 %mul
+; CHECK: ret i32 %x
+}
+