[Bug target/41156] [4.4/4.5 Regression] zlib segfault in inflate_table() compiled w/ -O -msse2 ftree-vectorize

["mahatma at eu dot by" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #23 from mahatma at eu dot by  2009-10-12 11:40 -------
(In reply to comment #22)

> We can't check Seamonkey into gcc/testsuite. We need something
> much smaller. 

I understand this. But even if I will use your testsuite addons (I unsure in
it, Gentoo "USE=test emerge sys-deve/gcc" on unpatched gcc & Celeron don't
breaks), unknown bug from at least old *-3.patch will be present. This is like
communicative problem, but problem...

> If you think adding -mstackrealign to your build is an acceptable solution,
> we can close this bug. Otherwise, please test my latest gcc 4.4 patch for
> PR 40838.  Thanks.

Your patch, by idea, more accurate - if now realign stack in ALL requred
places. But also it unmotivated realign with AMDs too. I alredy ask: "Why
-mstackrealign may be bad?". This is dark place. In manpage "-mstackrealign"
described against SSE aligning problem. This is like wellknown solution, but
unused wide. Why? What side-effects of "-mstackrealign"? Perfomance?
Compatibility? Just ABI standard? Related from this "-mstackrealign" may be
hardcoded for SSE in simple way - just "SSE -> -mstackrealign" or overcoded
patch to disable -mstackrealign for AMDs. Or unuse whole. I will not fast
testing your patch on old Celeron (after few days) to close this theme too, but
for final solution IMHO information about -mstackrealign [history] required.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41156