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From: "cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug lto/104237] [11 Regression] Emitted binary code changes when -g is enabled at -O1 -flto and optimize attribute since r11-3126-ga8f9b4c54cc35062 Date: Sat, 19 Feb 2022 08:02:05 +0000 [thread overview] Message-ID: <bug-104237-4-jTsbwMx8bd@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-104237-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104237 --- Comment #11 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-11 branch has been updated by Jakub Jelinek <jakub@gcc.gnu.org>: https://gcc.gnu.org/g:88ff2eb5cc2c1af2ae751c02997d0b5667662782 commit r11-9594-g88ff2eb5cc2c1af2ae751c02997d0b5667662782 Author: Jakub Jelinek <jakub@redhat.com> Date: Fri Jan 28 11:48:18 2022 +0100 cfgrtl: Fix up locus comparison in unique_locus_on_edge_between_p [PR104237] The testcase in the PR (not included for the testsuite because we don't have an (easy) way to -fcompare-debug LTO, we'd need 2 compilations/linking, one with -g and one with -g0 and -fdump-rtl-final= at the end of lto1 and compare that) has different code generation for -g vs. -g0. The difference appears during expansion, where we have a goto_locus that is at -O0 compared to the INSN_LOCATION of the previous and next insn across an edge. With -g0 the locations are equal and so no nop is added. With -g the locations aren't equal and so a nop is added holding that location. The reason for the different location is in the way how we stream in locations by lto1. We have lto_location_cache::apply_location_cache that is called with some set of expanded locations, qsorts them, creates location_t's for those and remembers the last expanded location. lto_location_cache::input_location_and_block when read in expanded_location is equal to the last expanded location just reuses the last location_t (or adds/changes/removes LOCATION_BLOCK in it), when it is not queues it for next apply_location_cache. Now, when streaming in -g input, we can see extra locations that don't appear with -g0, and if we are unlucky enough, those can be sorted last during apply_location_cache and affect what locations are used from the single entry cache next. In particular, second apply_location_cache with non-empty loc_cache in the testcase has 14 locations with -g0 and 16 with -g and those 2 extra ones sort both last (they are the same). The last one from -g0 then appears to be input_location_and_block sourced again, for -g0 triggers the single entry cache, while for -g it doesn't and so apply_location_cache will create for it another location_t with the same content. The following patch fixes it by comparing everything we care about the location instead (well, better in addition) to a simple location_t == location_t check. I think we don't care about the sysp flag for debug info... 2022-01-28 Jakub Jelinek <jakub@redhat.com> PR lto/104237 * cfgrtl.c (loc_equal): New function. (unique_locus_on_edge_between_p): Use it. (cherry picked from commit 430dca620fa3d03e53f6771a2b61d3f0ebb73756)
next prev parent reply other threads:[~2022-02-19 8:02 UTC|newest] Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-01-26 6:06 [Bug lto/104237] New: Emitted binary code changes when -g is enabled at -O1 -flto tlwang at uwaterloo dot ca 2022-01-26 6:13 ` [Bug lto/104237] Emitted binary code changes when -g is enabled at -O1 -flto and optimize attribute pinskia at gcc dot gnu.org 2022-01-26 8:39 ` [Bug lto/104237] [11/12 Regression] Emitted binary code changes when -g is enabled at -O1 -flto and optimize attribute since r11-3126-ga8f9b4c54cc35062 marxin at gcc dot gnu.org 2022-01-27 14:59 ` jakub at gcc dot gnu.org 2022-01-27 16:26 ` jakub at gcc dot gnu.org 2022-01-27 18:46 ` jakub at gcc dot gnu.org 2022-01-27 18:46 ` jakub at gcc dot gnu.org 2022-01-27 18:58 ` dmalcolm at gcc dot gnu.org 2022-01-28 10:49 ` cvs-commit at gcc dot gnu.org 2022-01-28 10:57 ` [Bug lto/104237] [11 " jakub at gcc dot gnu.org 2022-01-29 6:35 ` cnsun at uwaterloo dot ca 2022-01-29 9:07 ` jakub at gcc dot gnu.org 2022-02-19 8:02 ` cvs-commit at gcc dot gnu.org [this message] 2022-02-19 8:06 ` jakub at gcc dot gnu.org 2022-02-23 16:03 ` cnsun at uwaterloo dot ca 2022-03-08 20:34 ` cnsun at uwaterloo dot ca 2022-03-08 20:48 ` pinskia at gcc dot gnu.org 2022-03-08 20:49 ` jakub at gcc dot gnu.org 2022-03-08 21:07 ` cnsun at uwaterloo dot ca 2022-06-01 15:02 ` cnsun at uwaterloo dot ca 2022-06-01 16:23 ` pinskia at gcc dot gnu.org 2022-06-01 16:42 ` jakub at gcc dot gnu.org 2022-06-01 17:12 ` cnsun at uwaterloo dot ca
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