splitting add instructions

[Richard Henderson]

On 07/19/2011 08:08 AM, Paulo J. Matos wrote:
> So, this seems to have to do with the post-reload comparison optimization pass Richard mentioned.

Exactly.

> But I am still confused as to how GCC matches them. Is *_flags any
> special name GCC loops for (doubtful)?

No, and as you can see from the leading "*" in the name, the
name is not actually visible as a pattern.

As an experiment, please read the comment at the start of the
compare-elim.c file.  If you still do not understand how the
patch works, that suggests the documentation needs improvement.


r~