[Bug tree-optimization/61559] FAIL: gcc.dg/builtin-bswap-8.c on i686 with -mmovbe
rguenther at suse dot de
gcc-bugzilla@gcc.gnu.org
Thu Sep 4 09:16:00 GMT 2014
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61559
--- Comment #8 from rguenther at suse dot de <rguenther at suse dot de> ---
On Thu, 4 Sep 2014, ubizjak at gmail dot com wrote:
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61559
>
> --- Comment #7 from Uroš Bizjak <ubizjak at gmail dot com> ---
> (In reply to Richard Biener from comment #6)
>
> > Seems to me we want
> >
> > (bit_xor (bswap32 @0) (bswap32 @1)) -> (bswap32 (bit_xor @0 @1))
> >
> > in match-and-simplify speak.
>
> Please note that there are some more interesting transformations involving
> immediates and bit_not, as shown in builtin-bswap-8.c.
Added.
/* PR61559. Transforms for gcc.dg/builtin-bswap-8.c */
(for bswap in BUILT_IN_BSWAP16 BUILT_IN_BSWAP32 BUILT_IN_BSWAP64
(simplify
(bswap (bswap @0))
@0)
(simplify
(bswap (bit_not (bswap @0)))
(bit_not @0))
(for bitop in bit_xor bit_ior bit_and
(simplify
(bitop (bswap @0) (bswap @1))
(bswap (bitop @0 @1)))
(simplify
(bswap (bitop (bswap @0) INTEGER_CST@1))
(bitop @0 (bswap @1)))))
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