https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111334
--- Comment #15 from Xi Ruoyao <xry111 at gcc dot gnu.org> ---
(In reply to chenglulu from comment #13)
> (In reply to Xi Ruoyao from comment #12)
> > (In reply to chenglulu from comment #11)
> > > (In reply to Xi Ruoyao from comment #10)
> > > > (In reply to Xi Ruoyao from comment #9)
> > > >
> > > > > (define_insn "<optab>di3_fake"
> > > > > [(set (match_operand:DI 0 "register_operand" "=r,&r,&r")
> > > > > - (sign_extend:DI
> > > > > - (any_div:SI (match_operand:DI 1 "register_operand" "r,r,0")
> > > > > - (match_operand:DI 2 "register_operand"
> > > > > "r,r,r"))))]
> > > > > - ""
> > > > > + (if_then_else
> > > > > + (and (eq (match_operand:DI 1 "register_operand" "r,r,0")
> > > > > + (sign_extend:DI (subreg:SI (match_dup 1) 0)))
> > > > > + (eq (match_operand:DI 2 "register_operand" "r,r,r")
> > > > > + (sign_extend:DI (subreg:SI (match_dup 2) 0))))
> > > > > + (sign_extend:DI
> > > > > + (any_div:SI (subreg:SI (match_dup 1) 0)
> > > > > + (subreg:SI (match_dup 2) 0)))
> > > > > + (unspec:DI [(const_int 0)] UNSPEC_BAD_DIVW)))]
> > > >
> > > > With this the compiler will still believe all bad {div,mod}.w{,u}
> > >
> > > I think this is already defined as UNSPEC. Isn’t the simpler the logic,
> > > the
> > > better?
> >
> > Yes, I think we should just use 4 different UNSPEC_ values and the simple
> > version. But I've not find a way to use 4 different UNSPEC_ values in the
> > RTL template except duplicating everything 4 times...
>
> I still have a question that I don't quite understand, that is, why that the
> four generated strings are equivalent when using an UNSPEC name? My template
> names are different, and they will not be automatically matched during
> optimization.???
Oh I get it, you mean
(define_insn "<optab>di3_fake"
[(set (match_operand:DI 0 "register_operand" "=r,&r,&r")
(sign_extend:DI
- (any_div:SI (match_operand:DI 1 "register_operand" "r,r,0")
- (match_operand:DI 2 "register_operand" "r,r,r"))))]
+ (unspec:DI [(any_div:DI
+ (match_operand:DI 1 "register_operand" "r,r,0")
+ (match_operand:DI 2 "register_operand" "r,r,r"))]
+ UNSPEC_ANY_DIV)))]
""
{
return loongarch_output_division ("<insn>.w<u>\t%0,%1,%2", operands);
Good idea! I think it's better than my stupid hacks :).
I'd been thinking about:
(define_insn "<optab>di3_fake"
[(set (match_operand:DI 0 "register_operand" "=r,&r,&r")
(sign_extend:DI
- (any_div:SI (match_operand:DI 1 "register_operand" "r,r,0")
- (match_operand:DI 2 "register_operand" "r,r,r"))))]
+ (unspec:DI [(match_operand:DI 1 "register_operand" "r,r,0")
+ (match_operand:DI 2 "register_operand" "r,r,r")]
+ UNSPEC_ANY_DIV)))]
""
{
return loongarch_output_division ("<insn>.w<u>\t%0,%1,%2", operands);
and this is just wrong.
