------- Additional Comments From roger at eyesopen dot com 2005-04-03 03:20
-------
> Excuse me for asking, but what is it that makes the latest patch I posted not
> reasonable for the 4.0 timeframe?
The performance regression on C, Java, Ada and fortran code, that isn't affected
by this bug. The bug is marked has the "c++" component because it only affects
the C++ front-end. A fix that disables MIN_EXPR/MAX_EXPR optimizations in all
front-ends is not suitable for a release branch without SPEC testing to show how
badly innocent targets will get burnt! There may be lots of places in the Linux
kernel that depend upon generating min/max insns for performance reasons...
I'd hoped I'd made this clear when I proposed the alternate strategy of only
disabling this optimization *only* in the C++ front-end, and *only* prior to
tree-ssa. Whilst I agree this is a serious bug, it currently affects all
release branches, so taking a universal performance hit to resolve it without
considering the consequences seems a bad decision. Just grep for "MIN (" and
"MAX (" in GCC's own source code to see how badly this could impact the
compiler's own code/performance/bootstrap times.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19199
