http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57003
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|WAITING |NEW
Component|middle-end |rtl-optimization
Target Milestone|--- |4.8.1
Summary|gcc-4.8.0 breaks -O2 |[4.8/4.9 Regression]
|optimization with Wine(64) |gcc-4.8.0 breaks -O2
|- links/info/bisect of |optimization with Wine(64)
|commits included |- links/info/bisect of
| |commits included
--- Comment #15 from Jakub Jelinek <jakub at gcc dot gnu.org> 2013-04-24
16:50:21 UTC ---
Ah, ok, I can see it. To look at 22354 it helps to sed -i 's/^# .*$//', then
look for 22354 in the dump. Seems the code is still correct at *.ce3 pass,
Bernd's optimization kicks in during RA time before that and the pseudo holding
buffer is assigned to %rdi before the call memcpy and assumed to live in %rax
right after the call. But cprop_hardreg breaks this, changes the %rax after
the memcpy call into %rdi, even when %rdi is call clobbered register, and even
the call pattern contains (clobber (reg:DI 5 di)) and REG_DEAD note for the
same register.
