https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104914
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
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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 ...
