[PATCH] [AArch64] Add add/sub/cmp/cmn aliases to MC AsmParser

Renato Golin renato.golin at linaro.org
Fri Jul 11 13:03:33 PDT 2014

On 11 July 2014 20:52, Jim Grosbach <grosbach at apple.com> wrote:
> I have the same question about a number of the other proposed patches of this nature. If the docs say we should support them, then I’m all for it. If they don’t, I’m very hesitant to do so. I don’t like adding undocumented extensions to the assembler syntax.

I see, makes sense.

It is possible that GCC already does that and maybe that's the reason
for the patch? (Arnaud?)

I don't have any interest in that kind of patch myself, unless GCC is
generating them and we need to consume, which would make a bit of
sense to add as a GNU extension.

About documentation, I don't think it's realistic to expect GNU folks
from documenting every extension in the assembler, as they have been
specifically lenient in that same area... :/

Back to the patch, the only explicit aliasing rules I've seen is
between CMP/CMN and ADDS/SUBS, but that doesn't automatically allow us
to convert negative immediate in the reverse operation.


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