[Bug tree-optimization/63380] [5 Regression] Wrong constant folding
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63380 --- Comment #7 from Richard Biener rguenth at gcc dot gnu.org --- Author: rguenth Date: Fri Oct 10 11:05:39 2014 New Revision: 216066 URL: https://gcc.gnu.org/viewcvs?rev=216066root=gccview=rev Log: 2014-10-10 Richard Biener rguent...@suse.de PR tree-optimization/63380 * tree-ssa-tail-merge.c (stmt_local_def): Exclude stmts that may trap. * gcc.dg/torture/pr63380-1.c: New testcase. * gcc.dg/torture/pr63380-2.c: Likewise. Added: branches/gcc-4_9-branch/gcc/testsuite/gcc.dg/torture/pr63380-1.c branches/gcc-4_9-branch/gcc/testsuite/gcc.dg/torture/pr63380-2.c Modified: branches/gcc-4_9-branch/gcc/ChangeLog branches/gcc-4_9-branch/gcc/testsuite/ChangeLog branches/gcc-4_9-branch/gcc/tree-ssa-tail-merge.c
[Bug tree-optimization/63380] [5 Regression] Wrong constant folding
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63380 --- Comment #4 from Richard Biener rguenth at gcc dot gnu.org --- *** Bug 63381 has been marked as a duplicate of this bug. ***
[Bug tree-optimization/63380] [5 Regression] Wrong constant folding
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63380 Richard Biener rguenth at gcc dot gnu.org changed: What|Removed |Added Status|ASSIGNED|RESOLVED Resolution|--- |FIXED --- Comment #6 from Richard Biener rguenth at gcc dot gnu.org --- Fixed.
[Bug tree-optimization/63380] [5 Regression] Wrong constant folding
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63380 --- Comment #5 from Richard Biener rguenth at gcc dot gnu.org --- Author: rguenth Date: Thu Oct 9 12:45:07 2014 New Revision: 216038 URL: https://gcc.gnu.org/viewcvs?rev=216038root=gccview=rev Log: 2014-10-09 Richard Biener rguent...@suse.de PR tree-optimization/63380 * tree-ssa-tail-merge.c (stmt_local_def): Exclude stmts that may trap. * gcc.dg/torture/pr63380-1.c: New testcase. * gcc.dg/torture/pr63380-2.c: Likewise. Added: trunk/gcc/testsuite/gcc.dg/torture/pr63380-1.c trunk/gcc/testsuite/gcc.dg/torture/pr63380-2.c Modified: trunk/gcc/ChangeLog trunk/gcc/testsuite/ChangeLog trunk/gcc/tree-ssa-tail-merge.c
[Bug tree-optimization/63380] [5 Regression] Wrong constant folding
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63380
--- Comment #3 from Richard Biener rguenth at gcc dot gnu.org ---
Hmm. We end up with
main ()
{
int d.0_4;
int e.1_5;
int _7;
int b.7_11;
int a.8_12;
bb 2:
d.0_4 = d;
e.1_5 = 1 d.0_4;
e = e.1_5;
_7 = 31 / 0;
in the end. Which is caused by tail-merging (part of PRE) optimizing
bb 2:
d.0_4 = d;
e.1_5 = 1 d.0_4;
e = e.1_5;
if (e.1_5 = 0)
goto bb 10;
else
goto bb 3;
bb 10:
goto bb 4;
bb 3:
_7 = 31 / 0;
bb 4:
by removing bb 3 as having no side-effect appearantly (_7 is unused). It
produces
bb 2:
d.0_4 = d;
e.1_5 = 1 d.0_4;
e = e.1_5;
bb 3:
_7 = 31 / 0;
bb 4:
not sure how it ends up doing that (I suppose it has code to merge an
if diamond).
[Bug tree-optimization/63380] [5 Regression] Wrong constant folding
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63380 Richard Biener rguenth at gcc dot gnu.org changed: What|Removed |Added Status|NEW |ASSIGNED Assignee|unassigned at gcc dot gnu.org |rguenth at gcc dot gnu.org --- Comment #2 from Richard Biener rguenth at gcc dot gnu.org --- Mine.
[Bug tree-optimization/63380] [5 Regression] Wrong constant folding
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63380 Marek Polacek mpolacek at gcc dot gnu.org changed: What|Removed |Added Status|UNCONFIRMED |NEW Last reconfirmed||2014-10-02 CC||mpolacek at gcc dot gnu.org Target Milestone|--- |5.0 Summary|Wrong constant folding |[5 Regression] Wrong ||constant folding Ever confirmed|0 |1 --- Comment #1 from Marek Polacek mpolacek at gcc dot gnu.org --- Works with -fno-tree-vrp. Seems to have started with r211904.
