[Bug rtl-optimization/31849] Code size regression caused by fix to PR 31360

[pinskia at gcc dot gnu dot org]

------- Comment #2 from pinskia at gcc dot gnu dot org  2007-05-07 02:36 -------
> 1) Hoists a register containing 0 out of the loop
The correct thing to do.
>2) Uses that *only* as a copy into another register (mov reg, #0 costs exactly
the same as mov reg, reg)
Interesting, but this is also true on ppc where I reported the original
problem.

> 3) By doing the above, somehow prevents the post-increment sequence from being
found.
This might be the true issue.  But is this a regression from 4.1 where loop.c
would actually move this invariant?


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31849