My super-optimizer noticed that we weren't folding this expression to

true: (x *nsw x) sgt 0, where x = (y | 1).  This occurs in 464.h264ref.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@143028 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 31 insertions, 0 deletions

diff --git a/test/Transforms/InstSimplify/compare.ll b/test/Transforms/InstSimplify/compare.ll
index 2cbd641a74..3ece118902 100644
--- a/test/Transforms/InstSimplify/compare.ll
+++ b/test/Transforms/InstSimplify/compare.ll
@@ -323,3 +323,34 @@ define i1 @and1(i32 %X) {
   ret i1 %B
 ; CHECK: ret i1 false
 }
+
+define i1 @mul1(i32 %X) {
+; CHECK: @mul1
+; Square of a non-zero number is non-zero if there is no overflow.
+  %Y = or i32 %X, 1
+  %M = mul nuw i32 %Y, %Y
+  %C = icmp eq i32 %M, 0
+  ret i1 %C
+; CHECK: ret i1 false
+}
+
+define i1 @mul2(i32 %X) {
+; CHECK: @mul2
+; Square of a non-zero number is positive if there is no signed overflow.
+  %Y = or i32 %X, 1
+  %M = mul nsw i32 %Y, %Y
+  %C = icmp sgt i32 %M, 0
+  ret i1 %C
+; CHECK: ret i1 true
+}
+
+define i1 @mul3(i32 %X, i32 %Y) {
+; CHECK: @mul3
+; Product of non-negative numbers is non-negative if there is no signed overflow.
+  %XX = mul nsw i32 %X, %X
+  %YY = mul nsw i32 %Y, %Y
+  %M = mul nsw i32 %XX, %YY
+  %C = icmp sge i32 %M, 0
+  ret i1 %C
+; CHECK: ret i1 true
+}