[InstCombine] add test for vectors with undef elts; NFC

llvm-svn: 326661

diff --git a/llvm/test/Transforms/InstCombine/sub.ll b/llvm/test/Transforms/InstCombine/sub.ll
index 405320ba74cb5901bb4890ee86e19edd700ca1cc..0d4f87714b9075648697b29f6a23dcdeb7d430b5 100644 (file)
--- a/llvm/test/Transforms/InstCombine/sub.ll
+++ b/llvm/test/Transforms/InstCombine/sub.ll
@@ -40,7 +40,6 @@ define i32 @test4(i32 %A, i32 %x) {
   ret i32 %C
 }
 
-; FIXME:
 ; (~X) - (~Y) --> Y - X
 ; Also, show that we can handle extra uses and vectors.
 
@@ -74,6 +73,20 @@ define <2 x i8> @notnotsub_vec(<2 x i8> %x, <2 x i8> %y) {
   ret <2 x i8> %sub
 }
 
+; FIXME:
+define <2 x i8> @notnotsub_vec_undef_elts(<2 x i8> %x, <2 x i8> %y) {
+; CHECK-LABEL: @notnotsub_vec_undef_elts(
+; CHECK-NEXT:    [[NX:%.*]] = xor <2 x i8> [[X:%.*]], <i8 undef, i8 -1>
+; CHECK-NEXT:    [[NY:%.*]] = xor <2 x i8> [[Y:%.*]], <i8 -1, i8 undef>
+; CHECK-NEXT:    [[SUB:%.*]] = sub <2 x i8> [[NX]], [[NY]]
+; CHECK-NEXT:    ret <2 x i8> [[SUB]]
+;
+  %nx = xor <2 x i8> %x, <i8 undef, i8 -1>
+  %ny = xor <2 x i8> %y, <i8 -1, i8 undef>
+  %sub = sub <2 x i8> %nx, %ny
+  ret <2 x i8> %sub
+}
+
 define i32 @test5(i32 %A, i32 %B, i32 %C) {
 ; CHECK-LABEL: @test5(
 ; CHECK-NEXT:    [[D1:%.*]] = sub i32 [[C:%.*]], [[B:%.*]]