https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94291
--- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jakub Jelinek <ja...@gcc.gnu.org>: https://gcc.gnu.org/g:c23c899aedf11069e992eed7358802b262d62f98 commit r10-7607-gc23c899aedf11069e992eed7358802b262d62f98 Author: Jakub Jelinek <ja...@redhat.com> Date: Tue Apr 7 21:30:12 2020 +0200 combine: Fix split_i2i3 ICE [PR94291] The following testcase ICEs on armv7hl-linux-gnueabi. try_combine is called on: (gdb) p debug_rtx (i3) (insn 20 12 22 2 (set (mem/c:SI (plus:SI (reg/f:SI 102 sfp) (const_int -4 [0xfffffffffffffffc])) [1 x+0 S4 A32]) (reg:SI 125)) "pr94291.c":7:8 241 {*arm_movsi_insn} (expr_list:REG_DEAD (reg:SI 125) (nil))) (gdb) p debug_rtx (i2) (insn 12 7 20 2 (parallel [ (set (reg:CC 100 cc) (compare:CC (reg:SI 121 [ <retval> ]) (const_int 0 [0]))) (set (reg:SI 125) (reg:SI 121 [ <retval> ])) ]) "pr94291.c":7:8 248 {*movsi_compare0} (expr_list:REG_UNUSED (reg:CC 100 cc) (nil))) and tries to recognize cc = r121 cmp 0; [sfp-4] = r121 parallel, but that isn't recognized, so it splits it into two: split_i2i3 [sfp-4] = r121 followed by cc = r121 cmp 0 which is recognized, but ICEs because the code below insist that the SET_DEST of newi2pat (or first set in PARALLEL thereof) must be a REG or SUBREG of REG, but it is a MEM in this case. I don't see any condition that would guarantee that, perhaps for the swap_i2i3 case it was somehow guaranteed. As the code just wants to update LOG_LINKS and LOG_LINKS are only for registers, not for MEM or anything else, the patch just doesn't update those if it isn't a REG or SUBREG of REG. 2020-04-07 Jakub Jelinek <ja...@redhat.com> PR rtl-optimization/94291 PR rtl-optimization/84169 * combine.c (try_combine): For split_i2i3, don't assume SET_DEST must be a REG or SUBREG of REG; if it is not one of these, don't update LOG_LINKs. * gcc.dg/pr94291.c: New test.
