[Bug other/91730] [10 regression] r275518 causes 3 verification errors in the cpu 2006 test suite
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91730 Tamar Christina changed: What|Removed |Added CC||tnfchris at gcc dot gnu.org --- Comment #9 from Tamar Christina --- Hmm yes the transformation is too aggressive and incorrect here. we'll fix that and resubmit a fixed patch.
[Bug other/91730] [10 regression] r275518 causes 3 verification errors in the cpu 2006 test suite
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91730 Richard Biener changed: What|Removed |Added Status|NEW |RESOLVED Resolution|--- |FIXED --- Comment #8 from Richard Biener --- Reverted the patch.
[Bug other/91730] [10 regression] r275518 causes 3 verification errors in the cpu 2006 test suite
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91730 --- Comment #7 from Richard Biener --- Note in all cases of the testcases coming with the patch the sources are eventually casted from float to double.
[Bug other/91730] [10 regression] r275518 causes 3 verification errors in the cpu 2006 test suite
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91730 --- Comment #6 from Richard Biener --- (In reply to Martin Liška from comment #5) > The transformation is from: > > _663 = T1$1_55 + _293; > _651 = (float) _663; > > where T1$1_55 and _293 are doubles. To: > > _758 = (float) T1$1_55; > _759 = (float) _293; > _760 = _758 + _759; > _651 = (float) _760; OK, so thats invalid for example when T1$1_55 and _293 are FP values that cannot be represented in 'float' but their sum can. That's outside of what we generally allow with -ffast-math. It would be valid if one of T1$1_55 or _293 are already float.
[Bug other/91730] [10 regression] r275518 causes 3 verification errors in the cpu 2006 test suite
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91730 --- Comment #5 from Martin Liška --- The transformation is from: _663 = T1$1_55 + _293; _651 = (float) _663; where T1$1_55 and _293 are doubles. To: _758 = (float) T1$1_55; _759 = (float) _293; _760 = _758 + _759; _651 = (float) _760;
[Bug other/91730] [10 regression] r275518 causes 3 verification errors in the cpu 2006 test suite
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91730 --- Comment #4 from Martin Liška --- Created attachment 46869 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=46869=edit Dump file without problematic transformation
[Bug other/91730] [10 regression] r275518 causes 3 verification errors in the cpu 2006 test suite
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91730 --- Comment #3 from Martin Liška --- Created attachment 46868 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=46868=edit Dump file with problematic transformation For the 453.povray (which fails with --size=test), the problematic file is: g++ -c -o quadrics.o -dspec_cpu -dndebug -ofast -g -fpermissive -dspec_cpu_lp64 quadrics.cpp -fdbg-cnt=match:4030 Where match:4030 is the first bad debug counter value.
[Bug other/91730] [10 regression] r275518 causes 3 verification errors in the cpu 2006 test suite
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91730 Martin Liška changed: What|Removed |Added Status|UNCONFIRMED |NEW Last reconfirmed||2019-09-11 CC||marxin at gcc dot gnu.org Ever confirmed|0 |1 --- Comment #2 from Martin Liška --- I can confirm that and I'm going to bisect the transformation.
[Bug other/91730] [10 regression] r275518 causes 3 verification errors in the cpu 2006 test suite
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91730 Richard Biener changed: What|Removed |Added Target|powerpc64le-unknown-linux-g |powerpc64le-unknown-linux-g |nu |nu, x86_64-*-* CC||barnaby.wilks at arm dot com Blocks||26163 Target Milestone|--- |10.0 --- Comment #1 from Richard Biener --- Using -Ofast I presume? Note there's the 'match' debug-counter you can use to bisect the offending transform (per source file of course). Confirmed on a Haswell machine with -Ofast -march=native as well. Not exactly wrong-code confirmed yet but we'd like to have SPEC CPU "-Ofast clean" and thus need to understand what actual transform is bad here. Referenced Bugs: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=26163 [Bug 26163] [meta-bug] missed optimization in SPEC (2k17, 2k and 2k6 and 95)
