https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111283
--- Comment #10 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Sergei Trofimovich <sly...@gcc.gnu.org>: https://gcc.gnu.org/g:043a6fcbc27f8721301eb2f72a7839f54f393003 commit r14-4421-g043a6fcbc27f8721301eb2f72a7839f54f393003 Author: Sergei Trofimovich <siarh...@google.com> Date: Wed Sep 27 14:29:12 2023 +0100 ipa-utils: avoid uninitialized probabilities on ICF [PR111559] r14-3459-g0c78240fd7d519 "Check that passes do not forget to define profile" exposed check failures in cases when gcc produces uninitialized profile probabilities. In case of PR/111559 uninitialized profile is generated by edges executed 0 times reported by IPA profile: $ gcc -O2 -fprofile-generate pr111559.c -o b -fopt-info $ ./b $ gcc -O2 -fprofile-use -fprofile-correction pr111559.c -o b -fopt-info pr111559.c: In function 'rule1': pr111559.c:6:13: error: probability of edge 3->4 not initialized 6 | static void rule1(void) { if (p) edge(); } | ^~~~~ during GIMPLE pass: fixup_cfg pr111559.c:6:13: internal compiler error: verify_flow_info failed The change conservatively ignores updates with zero execution counts and uses initially assigned probabilities (`always` probability in case of the example). PR ipa/111283 PR gcov-profile/111559 gcc/ * ipa-utils.cc (ipa_merge_profiles): Avoid producing uninitialized probabilities when merging counters with zero denominators. gcc/testsuite/ * gcc.dg/tree-prof/pr111559.c: New test.
