[PATCH] Reduce conservativeness in REE using machine model (issue6631066)

[Steven Bosscher]

On Wed, Oct 10, 2012 at 11:25 PM, Teresa Johnson <tejohnson@google.com> wrote:
> What I did to address this is to call get_attr_mode from the machine model
> to get the actual mode of the insn. In this case, it returns MODE_SI.
> There doesn't seem to be any code that maps from the attr_mode (MODE_SI)
> to the machine_mode (SImode), so I am doing the mapping in ree.c before
> the comparison with the mode from the second extend.

The "mode" attribute is not a default attribute, i.e. targets are free
to define an attribute mode with target-specific semantics. So AFAIU,
I don't think you can just use the i386 "mode" attribute in ree.c.

So maybe you need a target hook, something similar to mode_rep_extended.

Ciao!
Steven