https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105455
--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-12 branch has been updated by Alexandre Oliva <aol...@gcc.gnu.org>: https://gcc.gnu.org/g:e628690d6333f0cc4d338cd8b796408f35e07ced commit r12-8372-ge628690d6333f0cc4d338cd8b796408f35e07ced Author: Alexandre Oliva <ol...@adacore.com> Date: Fri May 13 03:05:46 2022 -0300 [PR105455] Set edge probabilities when hardening conditionals When turning unconditional edges into conditional, as in gimple-harden-conditionals.cc:insert_check_and_trap, the newly-created edge's probability comes out uninitialized, while the previously unconditional edge's probability is presumably profile_probability::always. Mixing initialized and uninitialized probabilities before expand breaks predict.cc:force_edge_cold: the initialized probability may end up copied to a REG_BR_PROB note in a conditional branch insn, but if force_edge_cold is called on that edge, it will find another edge with uninitialized probability and assume the note is absent. Later on, rtl_verify_edges complains that the note does not match the probability modified by force_edge_cold in the edge. This patch sets probabilities for edges affected by hardening of conditionals, both the newly-created edges to trap blocks and the previously-unconditional edges, so that the former are considered never taken, while the latter are confirmed as always taken. for gcc/ChangeLog PR rtl-optimization/105455 * gimple-harden-conditionals.cc (insert_check_and_trap): Set probabilities for newly-conditional edges. for gcc/testsuite/ChangeLog PR rtl-optimization/105455 * gcc.dg/pr105455.c: New. (cherry picked from commit 90a8eab4a1292430467f68b65e5127f7760acc94)
