[PATCH] D20456: [CodeGen] Fix problem with X86 byte registers in CriticalAntiDepBreaker

[Matthias Braun via llvm-commits]

MatzeB added a comment.

In http://reviews.llvm.org/D20456#439854, @spatel wrote:

> In http://reviews.llvm.org/D20456#439675, @mbodart wrote:
>
> > Sanjay, I tried backing out your fix for pr20020.ll, but the test passes either way.  So something else changed along the way.
>
>
> I confirmed that locally. There's no difference in the asm for that code after backing out the tied operand blob, so it's not just due to bogus CHECK lines in the test. I also confirmed that the original C program from PR20020 is not crashing anymore even without the changes from r212275.


>From a high level the fix in your revision does make sense to me. We cannot just rename the input of a two-address instruction when we do not rename the output at the same time.


http://reviews.llvm.org/D20456