InstSimplify: Don't allow (x srem y) urem y -> x srem y
Let's consider the case where:
%x i16 = 32768
%y i16 = 384
%x srem %y = 65408
(%x srem %y) urem %y = 128
llvm-svn: 217939
diff --git a/llvm/test/Transforms/InstSimplify/rem.ll b/llvm/test/Transforms/InstSimplify/rem.ll
index b757ccd..f5ea451 100644
--- a/llvm/test/Transforms/InstSimplify/rem.ll
+++ b/llvm/test/Transforms/InstSimplify/rem.ll
@@ -16,11 +16,30 @@
; CHECK: ret i32 0
}
-define i32 @select3(i32 %x, i32 %n) {
-; CHECK-LABEL: @select3(
+define i32 @rem1(i32 %x, i32 %n) {
+; CHECK-LABEL: @rem1(
; CHECK-NEXT: %mod = srem i32 %x, %n
; CHECK-NEXT: ret i32 %mod
%mod = srem i32 %x, %n
%mod1 = srem i32 %mod, %n
ret i32 %mod1
}
+
+define i32 @rem2(i32 %x, i32 %n) {
+; CHECK-LABEL: @rem2(
+; CHECK-NEXT: %mod = urem i32 %x, %n
+; CHECK-NEXT: ret i32 %mod
+ %mod = urem i32 %x, %n
+ %mod1 = urem i32 %mod, %n
+ ret i32 %mod1
+}
+
+define i32 @rem3(i32 %x, i32 %n) {
+; CHECK-LABEL: @rem3(
+; CHECK-NEXT: %[[srem:.*]] = srem i32 %x, %n
+; CHECK-NEXT: %[[urem:.*]] = urem i32 %[[srem]], %n
+; CHECK-NEXT: ret i32 %[[urem]]
+ %mod = srem i32 %x, %n
+ %mod1 = urem i32 %mod, %n
+ ret i32 %mod1
+}