http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56982
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2013-04-16
CC| |jakub at gcc dot gnu.org
Target Milestone|--- |4.8.1
Summary|Bad optimization with |[4.8/4.9 Regression] Bad
|setjmp() |optimization with setjmp()
Ever Confirmed|0 |1
--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> 2013-04-16
15:46:43 UTC ---
Also happens with -Os. Started with http://gcc.gnu.org/r190284
Eyeballing the difference between r190283 and r190284 -Os dumps, I see that
*.copyrename4 is still the same appart from losing some SSA_NAME_VARs, but
*.uncprop has one difference:
- # n_13 = PHI <0(5), 1(6)>
+ # _13 = PHI <_3(5), 1(6)>
The missing n is fine, but _3 instead of 0 there supposedly isn't.
_3 is set before the setjmp call, while this PHI is after the returns-twice
function, and while for non-zero _3 the code before setjmp exits early, so _3
should contain 0, perhaps while extending the lifetime of _3 over the returns
twice function it should have added SSA_NAME_OCCURS_IN_ABNORMAL_PHI or give up
on it. Richard, can you please have a look?
