https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104914
Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- See Also| |https://gcc.gnu.org/bugzill | |a/show_bug.cgi?id=67736 --- Comment #9 from Andrew Pinski <pinskia at gcc dot gnu.org> --- (In reply to YunQiang Su from comment #8) > (In reply to Andrew Pinski from comment #7) > > The initial RTL has a signed extend in there: > > > > > > (insn 20 19 23 2 (set (reg/v:DI 200 [ val+-4 ]) > > (sign_extend:DI (subreg:SI (reg/v:DI 200 [ val+-4 ]) 4))) > > "/app/example.cpp":7:29 -1 > > (nil)) > > (jump_insn 23 20 24 2 (set (pc) > > (if_then_else (le (subreg/s/u:SI (reg/v:DI 200 [ val+-4 ]) 4) > > (const_int 0 [0])) > > (label_ref 32) > > (pc))) "/app/example.cpp":8:5 -1 > > (int_list:REG_BR_PROB 440234148 (nil)) > > -> 32) > > > > > > Before combine also looks fine: > > (insn 20 19 23 2 (set (reg/v:DI 200 [ val+-4 ]) > > (sign_extend:DI (subreg:SI (reg/v:DI 200 [ val+-4 ]) 4))) > > "/app/example.cpp":7:29 235 {extendsidi2} > > (nil)) > > Yes. I noticed it. while in mips.md, extendsidi2 is expanded to no > instructions at all. Right then the le should had a truncation before the use of SI mode here ...