[PATCH] D11678: [CodeGen] Fixes *absdiff* intrinsic: LangRef doc/test case improvement and corresponding code change

[Ahmed Bougacha via llvm-commits]

ab added a comment.

Thanks for the changes!

I'm still uncomfortable with the tests. The explicit CHECK-NEXT approach would apply much better to the smaller tests in _128.ll than the big v16i16 one, I think. Regexes would also help make the tests less brittle while keeping them as useful.

Also, should we merge the two test files together?  IMO, the _128/_256 distinction isn't very useful.


================
Comment at: test/CodeGen/X86/absdiff_128.ll:66-67
@@ +65,4 @@
+; CHECK:      movd
+; CHECK-DAG:  movzbl   {{.*}}, {{%.*}}
+; CHECK-DAG:  movzbl   {{.*}}, {{%.*}}
+; CHECK:      subl
----------------
These lines could be simplified into:


```
; CHECK: movzbl
; CHECK: movzbl

```

Ditto for others, e.g. pextrw below.

================
Comment at: test/CodeGen/X86/absdiff_256.ll:25-27
@@ +24,5 @@
+; CHECK-NEXT:    pandn %xmm1, %xmm5
+; CHECK-DAG:     psubw %xmm1, %xmm4
+; CHECK-DAG:     pxor %xmm0, %xmm3
+; CHECK:         pandn %xmm4, %xmm3
+; CHECK-NEXT:    por %xmm5, %xmm3
----------------
Why do these need CHECK-DAG?


http://reviews.llvm.org/D11678