http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58318
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |compile-time-hog
Status|UNCONFIRMED |NEW
Last reconfirmed| |2013-09-05
Version|unknown |4.9.0
Summary|very slow compilation on |very slow compilation on
|x86_64-linux with -O3 and |x86_64-linux with -O3 and
|-g |-g and checking enabled
Ever confirmed|0 |1
--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Confirmed. We completely unroll the loop nest in bar () after inlining foo ().
In the -g case we retain a ton of DEBUG_STMTs - 577185 - in a single basic
block. So walking all of them causes the slowdown, the walking done by
the verifiers - did you compare trunk with --enable-checking=release? I can
see the same stmts with using GCC 4.8.
A quick check with a non-bootstrapped cc1 but release checking makes the
slowdown go away.
Still, eventually the checkers may need some speed related TLC.
