https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114239
Bug ID: 114239 Summary: ice: error: definition in block does not dominate use in block Product: gcc Version: 14.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c Assignee: unassigned at gcc dot gnu.org Reporter: dcb314 at hotmail dot com Target Milestone: --- For this C code: int ip4_getbit_a, ip4_getbit_pos, ip4_clrbit_pos; void ip4_clrbit(int *a) { *a &= ip4_clrbit_pos; } typedef struct { char pxlen; int prefix } net_addr_ip4; void fib_get_chain(); int trie_match_longest_ip4(); int trie_match_next_longest_ip4(net_addr_ip4 *n) { int __trans_tmp_1; while (n->pxlen) { n->pxlen--; ip4_clrbit(&n->prefix); __trans_tmp_1 = ip4_getbit_a >> ip4_getbit_pos; if (__trans_tmp_1) return 1; } return 0; } void net_roa_check_ip4_trie_tab() { net_addr_ip4 px0; for (int _n = trie_match_longest_ip4(&px0); _n; _n = trie_match_next_longest_ip4(&px0)) fib_get_chain(); } on x86_64, does this: $ ../results/bin/gcc -c -O3 -march=znver3 -w ~/cvise/bug1021.c /home/dcb38/cvise/bug1021.c: In function ‘net_roa_check_ip4_trie_tab’: /home/dcb38/cvise/bug1021.c:20:6: error: definition in block 19 does not dominate use in block 14 20 | void net_roa_check_ip4_trie_tab() { | ^~~~~~~~~~~~~~~~~~~~~~~~~~ for SSA_NAME: _117 in statement: px0__lsm.22_47 = PHI <_117(14), _117(19)> PHI argument _117 for PHI node px0__lsm.22_47 = PHI <_117(14), _117(19)> during GIMPLE pass: vect /home/dcb38/cvise/bug1021.c:20:6: internal compiler error: verify_ssa failed The bug first seems to occur sometime between g:1e74ce8983fd4926 and g:71244316cf714725, which is 42 commits.