[Bug middle-end/45720] [4.6 regression] Revision 164367 miscompiled SPEC CPU 2K
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=45720 Bug 45720 depends on bug 43432, which changed state. Bug 43432 Summary: Missed vectorization: "complicated access pattern" for increasing and decreasing data indexing https://gcc.gnu.org/bugzilla/show_bug.cgi?id=43432 What|Removed |Added Status|WAITING |RESOLVED Resolution|--- |FIXED
[Bug middle-end/45720] [4.6 regression] Revision 164367 miscompiled SPEC CPU 2K
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45720 --- Comment #7 from Richard Guenther rguenth at gcc dot gnu.org 2010-10-22 08:59:56 UTC --- We need some sort of a testcase.
[Bug middle-end/45720] [4.6 regression] Revision 164367 miscompiled SPEC CPU 2K
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45720
--- Comment #8 from Vladimir Kharchenko vladimir.a.kharchenko at intel dot
com 2010-10-22 10:15:16 UTC ---
It can happen that this file is minimal test case. :(
The piece of source:
961 if ((l_maxabs = temp.s_max[rw]) 0)
962 {
963 l_maxabs = fabs(u.row.val[len]);
964
965 for (i = len - 1; i = beg; --i)
966if (l_maxabs fabs(u.row.val[i])) Seg. fault
967 l_maxabs = fabs(u.row.val[i]);
968
969 temp.s_max[rw] = l_maxabs; /* # */
970 }
is executed many times in this test before Segmentation fault.
GDB shows that all objects (l_maxabs, fabs(u.row.val[i]), len, i, beg) have
correct values after Seg exception. Instructions after disassembler:
0x0041385b soplex::CLUFactor::selectPivots(soplex::Real)+2203:
and$0x7,%r8d
0x0041385f soplex::CLUFactor::selectPivots(soplex::Real)+2207:
movapd 0x0(%rbp),%xmm2 Seg. fault
0x00413864 soplex::CLUFactor::selectPivots(soplex::Real)+2212:
cmp%r11d,%edx
also looks correct. %rbp points to correct memory.
So I have no hypotheses about the reason of this exception.
Maybe, it was indirect jump into the middle of instruction.
I will continue attemts to create short test case after weekend.
[Bug middle-end/45720] [4.6 regression] Revision 164367 miscompiled SPEC CPU 2K
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45720 --- Comment #9 from Uros Bizjak ubizjak at gmail dot com 2010-10-22 11:21:27 UTC --- (In reply to comment #8) So I have no hypotheses about the reason of this exception. Maybe, it was indirect jump into the middle of instruction. I will continue attemts to create short test case after weekend. Try to run the test under valgrind. This tool is much more powerful.
[Bug middle-end/45720] [4.6 regression] Revision 164367 miscompiled SPEC CPU 2K
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45720
Richard Guenther rguenth at gcc dot gnu.org changed:
What|Removed |Added
Status|UNCONFIRMED |NEW
Last reconfirmed||2010.10.22 12:25:43
Ever Confirmed|0 |1
--- Comment #10 from Richard Guenther rguenth at gcc dot gnu.org 2010-10-22
12:25:43 UTC ---
Peeling for alignment needs adjustment:
float val[256];
float x;
void __attribute__((noinline,noclone))
foo(int len, int beg)
{
int i;
for (i = len - 1; i = beg; --i)
x += val[i] * 2;
}
int main()
{
foo(256-3, 0);
return 0;
}
segfaults. We align val[len-1] instead of val[len-4].
[Bug middle-end/45720] [4.6 regression] Revision 164367 miscompiled SPEC CPU 2K
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45720 --- Comment #11 from Richard Guenther rguenth at gcc dot gnu.org 2010-10-22 13:22:18 UTC --- Created attachment 22116 -- http://gcc.gnu.org/bugzilla/attachment.cgi?id=22116 untested patch Patch which fixes the testcase (and some more).
[Bug middle-end/45720] [4.6 regression] Revision 164367 miscompiled SPEC CPU 2K
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45720 --- Comment #12 from Richard Guenther rguenth at gcc dot gnu.org 2010-10-22 14:44:53 UTC --- Author: rguenth Date: Fri Oct 22 14:44:48 2010 New Revision: 165832 URL: http://gcc.gnu.org/viewcvs?root=gccview=revrev=165832 Log: 2010-10-22 Richard Guenther rguent...@suse.de PR tree-optimization/45720 * tree-vect-data-refs.c (vect_update_misalignment_for_peel): Handle negative step. (vect_enhance_data_refs_alignment): Likewise. * tree-vect-loop-manip.c (vect_gen_niters_for_prolog_loop): Likewise. (vect_create_cond_for_align_checks): Likewise. (vect_create_cond_for_alias_checks): Likewise. * gcc.dg/torture/pr45720.c: New testcase. Added: trunk/gcc/testsuite/gcc.dg/torture/pr45720.c Modified: trunk/gcc/ChangeLog trunk/gcc/testsuite/ChangeLog trunk/gcc/tree-vect-data-refs.c trunk/gcc/tree-vect-loop-manip.c
[Bug middle-end/45720] [4.6 regression] Revision 164367 miscompiled SPEC CPU 2K
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45720 H.J. Lu hjl.tools at gmail dot com changed: What|Removed |Added Status|NEW |RESOLVED Resolution||FIXED --- Comment #13 from H.J. Lu hjl.tools at gmail dot com 2010-10-23 02:08:57 UTC --- Fixed as of revision 165840.
[Bug middle-end/45720] [4.6 regression] Revision 164367 miscompiled SPEC CPU 2K
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45720 --- Comment #2 from hjl at gcc dot gnu.org hjl at gcc dot gnu.org 2010-10-03 05:41:44 UTC --- Author: hjl Date: Sun Oct 3 05:39:32 2010 New Revision: 164914 URL: http://gcc.gnu.org/viewcvs?root=gccview=revrev=164914 Log: Disallow negative steps in vectorizer. gcc/ 2010-10-02 H.J. Lu hongjiu...@intel.com PR tree-optimization/45720 PR tree-optimization/45764 * tree-vect-data-refs.c (vect_analyze_data_ref_access): Don't accept backwards consecutive accesses. (vect_create_data_ref_ptr): Disallow negative steps. * tree-vect-stmts.c (vectorizable_store): Allow negative steps. (perm_mask_for_reverse): Removed. (reverse_vec_elements): Likewise. (vectorizable_load): Don't hanle negative steps. gcc/testsuite/ 2010-10-02 H.J. Lu hongjiu...@intel.com PR tree-optimization/45720 PR tree-optimization/45764 * g++.dg/torture/pr45764.C: New. * gcc.dg/vect/pr43432.c: Xfail. * gcc.dg/vect/vect-114.c: Likewise. * gcc.dg/vect/vect-15.c: Likewise. Added: trunk/gcc/testsuite/g++.dg/torture/pr45764.C Modified: trunk/gcc/ChangeLog trunk/gcc/testsuite/ChangeLog trunk/gcc/testsuite/gcc.dg/vect/pr43432.c trunk/gcc/testsuite/gcc.dg/vect/vect-114.c trunk/gcc/testsuite/gcc.dg/vect/vect-15.c trunk/gcc/tree-vect-data-refs.c trunk/gcc/tree-vect-stmts.c --- Comment #3 from Richard Guenther rguenth at gcc dot gnu.org 2010-10-21 10:03:49 UTC --- Likely a dup of PR45764 which has all the analysis.
[Bug middle-end/45720] [4.6 regression] Revision 164367 miscompiled SPEC CPU 2K
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45720 --- Comment #4 from H.J. Lu hjl.tools at gmail dot com 2010-10-21 16:28:24 UTC --- As of revision 165771, I still got With runspec -c lnx-i686-gcc.cfg -n 1 -l -o asc -I all -T peak *** Miscompare of ref.out, see /export/gnu/import/svn/gcc-test/spec/2000/i686/spec/benchspec/CINT2000/254.gap/run/0002/ref.out.mis Error: 1x254.gap With runspec -c lnx-x86_64-gcc.cfg -n 1 -l -o asc -I all -T peak *** Miscompare of crafty.out, see /export/gnu/import/svn/gcc-test/spec/2000/x86_64/spec/benchspec/CINT2000/186.crafty/run/0002/crafty.out.mis *** Miscompare of inp.out, see /export/gnu/import/svn/gcc-test/spec/2000/x86_64/spec/benchspec/CFP2000/200.sixtrack/run/0002/inp.out.mis Error: 1x186.crafty 1x200.sixtrack
[Bug middle-end/45720] [4.6 regression] Revision 164367 miscompiled SPEC CPU 2K
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45720 --- Comment #5 from H.J. Lu hjl.tools at gmail dot com 2010-10-22 00:28:51 UTC --- With SPEC CPU 2006, revision 165771 gave me: 1. 64bit using-O3 -funroll-loops -ffast-math: Running 450.soplex ref peak lnx32e-gcc default 450.soplex: copy 0 non-zero return code (exit code=0, signal=11) Running 481.wrf ref peak lnx32e-gcc default 481.wrf: copy 0 non-zero return code (exit code=0, signal=11) 2. 32bit using -O3 -funroll-loops -msse2 -mfpmath=sse -ffast-math: Running 481.wrf ref peak lnx32-gcc default 481.wrf: copy 0 non-zero return code (exit code=0, signal=11)
[Bug middle-end/45720] [4.6 regression] Revision 164367 miscompiled SPEC CPU 2K
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45720 --- Comment #6 from Vladimir Kharchenko vladimir.a.kharchenko at intel dot com 2010-10-22 04:28:46 UTC --- Quick investigation of 450.soplex failure shows that Segmentation fault is in line 966 (file factor.cc). When I recompiled this file without the option -ffast=math, test passed.
[Bug middle-end/45720] [4.6 regression] Revision 164367 miscompiled SPEC CPU 2K
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45720 Richard Guenther rguenth at gcc dot gnu.org changed: What|Removed |Added Priority|P3 |P1
[Bug middle-end/45720] [4.6 regression] Revision 164367 miscompiled SPEC CPU 2K
-- hjl dot tools at gmail dot com changed: What|Removed |Added Target Milestone|--- |4.6.0 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45720
[Bug middle-end/45720] [4.6 regression] Revision 164367 miscompiled SPEC CPU 2K
--- Comment #1 from rguenth at gcc dot gnu dot org 2010-09-18 18:45 --- I also see 450.soplex and 481.wrf fail. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45720
