http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38518
--- Comment #8 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #7)
> Fixing this DF issue get's us down to
>
> loop invariant motion : 0.14 ( 0%) usr 0.01 ( 1%) sys 0.14 ( 0%)
> wall 148 kB ( 0%) ggc
> loop unswitching : 15.44 (30%) usr 0.02 ( 3%) sys 15.48 (29%)
> wall 0 kB ( 0%) ggc
> TOTAL : 52.26 0.73 52.99
> 456534 kB
>
> so finally a RTL unswitching slowness ;)
Fixing the same issue in loop-iv.c fixes that, too.
loop invariant motion : 0.18 ( 0%) usr 0.00 ( 0%) sys 0.16 ( 0%) wall
148 kB ( 0%) ggc
loop unswitching : 0.01 ( 0%) usr 0.00 ( 0%) sys 0.01 ( 0%) wall
0 kB ( 0%) ggc
TOTAL : 37.14 0.67 37.80
456534 kB
