[Bug tree-optimization/61576] [4.10 Regression] wrong code at -O3 on x86_64-linux-gnu
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61576 --- Comment #6 from Kirill Yukhin kyukhin at gcc dot gnu.org --- Author: kyukhin Date: Tue Jul 8 07:52:12 2014 New Revision: 212347 URL: https://gcc.gnu.org/viewcvs?rev=212347root=gccview=rev Log: PR tree-optimization/61576 gcc/ * tree-if-conv.c (is_cond_scalar_reduction): Add check that basic block containing reduction statement is predecessor of phi basi block. gcc/testsuite/ * gcc.dg/torture/pr61576.c: New test. Added: trunk/gcc/testsuite/gcc.dg/torture/pr61576.c Modified: trunk/gcc/ChangeLog trunk/gcc/testsuite/ChangeLog trunk/gcc/tree-if-conv.c
[Bug tree-optimization/61576] [4.10 Regression] wrong code at -O3 on x86_64-linux-gnu
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61576 Igor Zamyatin izamyatin at gmail dot com changed: What|Removed |Added CC||izamyatin at gmail dot com --- Comment #5 from Igor Zamyatin izamyatin at gmail dot com --- Patch is posted at http://gcc.gnu.org/ml/gcc-patches/2014-06/msg01866.html
[Bug tree-optimization/61576] [4.10 Regression] wrong code at -O3 on x86_64-linux-gnu
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61576 Jakub Jelinek jakub at gcc dot gnu.org changed: What|Removed |Added Status|UNCONFIRMED |NEW Last reconfirmed||2014-06-23 CC||chrbr at gcc dot gnu.org, ||jakub at gcc dot gnu.org Target Milestone|--- |4.10.0 Summary|wrong code at -O3 on|[4.10 Regression] wrong |x86_64-linux-gnu|code at -O3 on ||x86_64-linux-gnu Ever confirmed|0 |1 --- Comment #1 from Jakub Jelinek jakub at gcc dot gnu.org --- Worked up to and including r209971, started to ICE with r209972, that got fixed in r211263. The wrong-code started in r211302. Given that was a cost change, supposedly this has been latent before?
[Bug tree-optimization/61576] [4.10 Regression] wrong code at -O3 on x86_64-linux-gnu
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61576 --- Comment #2 from Richard Biener rguenth at gcc dot gnu.org --- Hmm, but it doesn't do any PHI hoisting. -fno-tree-loop-if-convert fixes it, -O2 -ftree-loop-if-convert breaks it.
[Bug tree-optimization/61576] [4.10 Regression] wrong code at -O3 on x86_64-linux-gnu
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61576 Richard Biener rguenth at gcc dot gnu.org changed: What|Removed |Added CC||ysrumyan at gmail dot com --- Comment #3 from Richard Biener rguenth at gcc dot gnu.org --- +Found cond scalar reduction. +d.6_12 = d_lsm.14_16 + 1;
[Bug tree-optimization/61576] [4.10 Regression] wrong code at -O3 on x86_64-linux-gnu
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61576
--- Comment #4 from Yuri Rumyantsev ysrumyan at gmail dot com ---
There is an issue with phi-node and reduction stmt - after r211302 new hammock
was inserted between reduction stmt and bb containing phi:
bb 6:
d.6_12 = d_lsm.14_17 + 1;
if (c.8_13 != 0)
goto bb 7;
else
goto bb 8;
bb 7:
bb 8:
# iftmp.7_15 = PHI 1(7), _19(6)
bb 9:
# d_lsm.14_16 = PHI d_lsm.14_17(5), d.6_12(8)
but algorithm for converting conditional scalar reduction assumes that basic
block containing reduction is one of predecessors of phi-block. I added check
on it and test is passed.
BTW I wonder why such code motion has been done - in fact, redundant
computations were introduced in loop, before this fix all computations related
to hammock were hoisted out off loop:
bb 4:
d_lsm.14_25 = d;
c.8_13 = c;
f.9_14 = f;
_18 = f.9_14 != 0;
_19 = (int) _18;
iftmp.7_15 = c.8_13 != 0 ? 1 : _19;
e_lsm.15_26 = e;
bb 5:
# d_lsm.14_17 = PHI d_lsm.14_25(4), d_lsm.14_16(9)
# e_lsm.15_1 = PHI e_lsm.15_26(4), e_lsm.15_24(9)
b.4_10 ={v} b;
if (b.4_10 != 0)
goto bb 6;
else
goto bb 7;
bb 6:
d.6_12 = d_lsm.14_17 + 1;
bb 7:
# d_lsm.14_16 = PHI d_lsm.14_17(5), d.6_12(6)
# e_lsm.15_24 = PHI e_lsm.15_1(5), iftmp.7_15(6)
I will send for review patch after required testing completion.
