[Bug debug/80025] [5/6/7 Regression] ICE w/ -O2 (-O3, -Ofast) -g -ftracer (infinite recursion in rtx_equal_for_cselib_1)
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80025 --- Comment #14 from Jakub Jelinek --- Author: jakub Date: Fri Mar 31 06:05:47 2017 New Revision: 246606 URL: https://gcc.gnu.org/viewcvs?rev=246606=gcc=rev Log: PR debug/80025 * cselib.h (rtx_equal_for_cselib_1): Add depth argument. (rtx_equal_for_cselib_p): Pass 0 to it. * cselib.c (cselib_hasher::equal): Likewise. (rtx_equal_for_cselib_1): Add depth argument. If depth is 128, don't look up VALUE locs and punt. Increment depth in recursive calls when walking VALUE locs. * gcc.dg/torture/pr80025.c: New test. Added: trunk/gcc/testsuite/gcc.dg/torture/pr80025.c Modified: trunk/gcc/ChangeLog trunk/gcc/cselib.c trunk/gcc/cselib.h trunk/gcc/testsuite/ChangeLog
[Bug debug/80025] [5/6/7 Regression] ICE w/ -O2 (-O3, -Ofast) -g -ftracer (infinite recursion in rtx_equal_for_cselib_1)
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80025 --- Comment #13 from Jakub Jelinek --- (In reply to Bernd Schmidt from comment #12) > That still doesn't seem to address the root cause though? Isn't the problem > that this reversible mappings code can create cycles and we should avoid > creating these in the first place? They can create cycles, but we can't avoid creating them generally, they are very important for the debug info quality; if there is no cycle, it isn't a problem, and determining whether there is a cycle is hard, because the locs lists aren't cast in stone, they actually can have further locs added or removed as the cselib processing goes on; and rtx_equal_for_cselib_1 is used while they are still in flux. Furthermore, even if there is a cycle, the comparison function might not run into the cycle. With the cap the comparison function might try to use some other location in another recursion level and be successful.
[Bug debug/80025] [5/6/7 Regression] ICE w/ -O2 (-O3, -Ofast) -g -ftracer (infinite recursion in rtx_equal_for_cselib_1)
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80025 --- Comment #12 from Bernd Schmidt --- That still doesn't seem to address the root cause though? Isn't the problem that this reversible mappings code can create cycles and we should avoid creating these in the first place?
[Bug debug/80025] [5/6/7 Regression] ICE w/ -O2 (-O3, -Ofast) -g -ftracer (infinite recursion in rtx_equal_for_cselib_1)
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80025 --- Comment #11 from Jakub Jelinek --- Created attachment 41034 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=41034=edit gcc7-pr80025.patch Untested alternate patch.
