I see a 14% slowdown with the SciMark sparse matrix multiplication benchmark
when going from 3.4.3 to 4.0.0 on my Gentoo box. Flags are -O3 -march=athlon-xp
-fomit-frame-pointer. I compiled and linked in one run of gcc, and ran the
executable from the command line with "time".
4.0's performance gets better (closer to 3.4's, which remains roughly constant)
as functions from the other files are moved into main.c. On those grounds, my
own inexpert opinion is that this regression stems from function inlining.
Earlier tests showed that the two versions are much closer when
-fomit-frame-pointer isn't used.
Will upload the preprocessed test cases that you're so fond of ;).
--
Summary: Optimizer regression: SciMark sparse matrix benchmark
Product: gcc
Version: 4.0.0
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: rtl-optimization
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: jbucata at tulsaconnect dot com
CC: gcc-bugs at gcc dot gnu dot org
GCC host triplet: i686-pc-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21676
