[PATCH] MIPS: gas: alter 64 or 32 for r6 triples if march is implicit

[YunQiang Su]

Jiaxun Yang <jiaxun.yang@flygoat.com> 于2023年5月6日周六 16:43写道：
>
>
>
> > 2023年5月6日 09:37，YunQiang Su <yunqiang.su@cipunited.com> 写道：
> >
> > When configure with triples mipsisa[32,64]r6[el,], the march value
> > is pinned to a fix value if not given explicitly. for example
> >   mipsisa32r6-linux-gnu -n32 xx.s
> > will complains that:
> >   -march=mips32r6 is not compatible with the selected ABI
> >
> > Since we are using these triples as a regular linux distributions,
> > let's alter march according to ABI.
>
> Hi,
>
> Hmm, why people wants to build n32 binary on mips32r6 CPU?

I guess o32 toolchain should not work only for 32bit CPU?

At seem time, this patch can solve some testcases in binutils-all
when configured with
       --target=mipsisa32r6-linux-gnu

> For multiline folks they should use mipsisa64r6 base triple which will accept
> all 3 ABIs.
>
> Thanks
> Jiaxun
>
>
> > ---
> > gas/config/tc-mips.c | 18 ++++++++++++++++++
> > 1 file changed, 18 insertions(+)
> >
> > diff --git a/gas/config/tc-mips.c b/gas/config/tc-mips.c
> > index 8a970ceada2..d99736df26a 100644
> > --- a/gas/config/tc-mips.c
> > +++ b/gas/config/tc-mips.c
> > @@ -20247,6 +20247,24 @@ mips_parse_cpu (const char *option, const char *cpu_string)
> >     : ISA_MIPS1);
> >     }
> >
> > +  /* mipsisa32r6-linux-gnu refuses -n32/-64 swtiches:
> > + -march=mips32r6 is not compatible with the selected ABI
> > +     Let's workaround it when -march options are not given explicitly.
> > +     We treat it some like -march=from-abi */
> > +  if ((strcasecmp (cpu_string, "mips32r6") == 0 || strcasecmp (cpu_string, "mips64r6") == 0)
> > + && strcasecmp (option, "default CPU") == 0)
> > +    {
> > +      if (ABI_NEEDS_32BIT_REGS (mips_abi))
> > + return mips_cpu_info_from_isa (ISA_MIPS32R6);
> > +
> > +      if (ABI_NEEDS_64BIT_REGS (mips_abi))
> > + return mips_cpu_info_from_isa (ISA_MIPS64R6);
> > +
> > +      if (file_mips_opts.gp >= 0)
> > + return mips_cpu_info_from_isa (file_mips_opts.gp == 32
> > +       ? ISA_MIPS32R6 : ISA_MIPS64R6);
> > +    }
> > +
> >   /* 'default' has traditionally been a no-op.  Probably not very useful.  */
> >   if (strcasecmp (cpu_string, "default") == 0)
> >     return 0;
> > --
> > 2.30.2
> >
>