https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125469
--- Comment #6 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-16 branch has been updated by Jakub Jelinek <[email protected]>: https://gcc.gnu.org/g:b4594399e84b3f48509d2303c176b926a5f415b0 commit r16-9187-gb4594399e84b3f48509d2303c176b926a5f415b0 Author: Jakub Jelinek <[email protected]> Date: Thu May 28 10:28:12 2026 +0200 i386: Fix up *add<mode>_1<nf_name> [PR125469] The following testcase ICEs, because combine matches (set (reg:DI 108) (plus:DI (reg:DI 104 [ s ]) (subreg:DI (reg:TI 103 [ _2 ]) 8))) Now, because ix86_validate_address_register has: 12038 /* Don't allow SUBREGs that span more than a word. It can 12039 lead to spill failures when the register is one word out 12040 of a two word structure. */ 12041 if (GET_MODE_SIZE (mode) > UNITS_PER_WORD) 12042 return NULL_RTX; this isn't recognized as *leadi, but is recognized as *adddi_1_nf pattern instead. Now, later on the RA turns it into: (set (reg:DI 2 cx [108]) (plus:DI (reg:DI 0 ax [orig:104 s ] [104]) (reg:DI 5 di [ _2+8 ]))) which would be valid *leadi, but given that INSN_CODE is already set to the *adddi_1_nf and that also satisfies it, nothing re-recognizes it as *leadi. But in that case without TARGET_APX_NDD the pattern has return "#"; That is a bug, because there is no splitter to split that (set (reg:DI 2 cx [108]) (plus:DI (reg:DI 0 ax [orig:104 s ] [104]) (reg:DI 5 di [ _2+8 ]))) into itself so that it is re-recognized as *leadi, so it just ICEs. I think having a splitter to split to the same thing would be just weird, so this just outputs lea insn directly. 2026-05-28 Jakub Jelinek <[email protected]> PR target/125469 * config/i386/i386.md (*add<mode>_1<nf_name>): Don't return "#" for the lea non-TARGET_APX_NDD case, instead emit a lea directly. * gcc.target/i386/apx-nf-pr125469.c: New test. Reviewed-by: Uros Bizjak <[email protected]> (cherry picked from commit 896c822afed0aad4c0ca761777cdc5f0085bbce0)
