http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57690
Uroš Bizjak <ubizjak at gmail dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2013-06-30
Ever confirmed|0 |1
--- Comment #1 from Uroš Bizjak <ubizjak at gmail dot com> ---
For some reason combine simplifies
(zero_extend:DI (lshiftrt:SI (reg:SI 0 ax [orig:65 D.1730 ] [65])
(const_int 2 [0x2]))))
to
(set (reg:DI 0 ax [orig:64 D.1733 ] [64])
(zero_extract:DI (reg:DI 0 ax [orig:59 D.1732 ] [59])
(const_int 30 [0x1e])
(const_int 2 [0x2])))
perhaps correct RTX costs could prevent this transformation for -Os?
