https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65249
--- Comment #7 from Oleg Endo <olegendo at gcc dot gnu.org> --- Created attachment 34902 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=34902&action=edit Various R0 pre-alloc splits I've tried compiling CSiBE with the two split patterns in comment #5 ... It's a can of worms. I'm dumping my current state as a patch here, maybe it's helpful in some way. I ended up adding one r0 split pattern after another, but probably some are still missing. bzip2 (haven't tried anything else so far) fails with: internal compiler error: in spill_failure, at reload1.c:2143 error: this is the insn: (insn 8965 8964 8966 70 (set (mem:SI (plus:SI (reg:SI 0 r0) (reg:SI 945 [ D.5064 ])) [1 MEM[base: _692, index: _1412, offset: 0B]+0 S4 A32]) (reg:SI 7 r7 [orig:592 D.5066 ] [592])) bzip2-1.0.2/blocksort.c:564 252 {movsi_ie} (expr_list:REG_DEAD (reg:SI 7 r7 [orig:592 D.5066 ] [592]) (expr_list:REG_DEAD (reg:SI 0 r0) (nil)))) Probably reload can't resolve adjacent insns which have r0 constraints. I haven't checked the details though. Regardless of that, I think the cmpeqsi_t hunk in sh.md and the sh_disp_addr_displacement huink in predicates.md should be applied on trunk.
