This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: [PATCH 2/3][AArch64] Improve zero extend
Richard Earnshaw wrote:
> Why does combine care what the cost is if the instruction isn't valid?
No idea. Combine does lots of odd things that don't make sense to me.
Unfortunately the costs we give for cases like this need to be accurate or
they negatively affect code quality. The reason for this patch was to fix
some unexpected slowdowns caused by the cost for zero_extend being
too high.
Wilco