For this C code: nilfs_bmap_find_target_seq_bmap; unsigned long nilfs_bmap_find_target_seq_bmap_0; unsigned long nilfs_bmap_find_target_seq() { if (nilfs_bmap_find_target_seq_bmap && nilfs_bmap_find_target_seq_bmap_0 + nilfs_bmap_find_target_seq_bmap) return nilfs_bmap_find_target_seq_bmap_0 + nilfs_bmap_find_target_seq_bmap; else return 0; } compiled by recent gcc trunk, does this: $ ../results/bin/gcc -c -w -O1 bug908.c bug908.c: In function ‘nilfs_bmap_find_target_seq’: bug908.c:9:1: error: definition in block 3 does not dominate use in block 4 9 | } | ^ for SSA_NAME: _5 in statement: # VUSE <.MEM_10(D)> return _5; during GIMPLE pass: phiopt bug908.c:9:1: internal compiler error: verify_ssa failed 0x107ae4f verify_ssa(bool, bool) ../../trunk.year/gcc/tree-ssa.cc:1211 This seems to have broken between git hash g:7e26fd6bcd39f53b and g:ff8f95449350372b, which is 6 revisions.
Started with r14-169-g84325f1c6aa3c5.
I had already posted a fix for this (and approved already): https://gcc.gnu.org/pipermail/gcc-patches/2023-April/616499.html I will add the testcase.
Another test case, this time in C++: struct { int second; } selectPlayer_playerRes; int selectPlayer_playerRes_0; int selectPlayer() { if (selectPlayer_playerRes_0 && selectPlayer_playerRes.second >= 0) return selectPlayer_playerRes.second; else return -1; }
The trunk branch has been updated by Andrew Pinski <pinskia@gcc.gnu.org>: https://gcc.gnu.org/g:2f58dd71d1b8e23f28a43360742519e92ee0c8d5 commit r14-199-g2f58dd71d1b8e23f28a43360742519e92ee0c8d5 Author: Andrew Pinski <apinski@marvell.com> Date: Thu Apr 20 09:23:25 2023 -0700 PHIOPT: Move check on diamond bb to tree_ssa_phiopt_worker from minmax_replacement This moves the check to make sure on the diamond shaped form bbs that the the two middle bbs are only for that diamond shaped form earlier in the shared code. Also remove the redundant check for single_succ_p since that was already done before hand. The next patch will simplify the code even further and remove redundant checks. PR tree-optimization/109604 gcc/ChangeLog: * tree-ssa-phiopt.cc (tree_ssa_phiopt_worker): Move the diamond form check from ... (minmax_replacement): Here. gcc/testsuite/ChangeLog: * gcc.c-torture/compile/pr109604-1.c: New test. * gcc.c-torture/compile/pr109604-2.c: New test.
Fixed.