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Re: [PATCH] MIPS: Add a GNU attribute for -mips32 -mfp64 objects
Thiemo Seufer <firstname.lastname@example.org> writes:
> Richard Sandiford wrote:
>> Paul Koning <email@example.com> writes:
>> >>>>>> "Richard" == Richard Sandiford <firstname.lastname@example.org> writes:
>> > Richard> I agree with Joseph here. Although it's redundant to
>> > Richard> specify -mfp64 with -msoft-float, it isn't actively wrong.
>> > Richard> The options have traditionally been orthogonal. I don't
>> > Richard> think the assembler should assume that -mfp64 implies
>> > Richard> -mhard-float.
>> > It seems strange, since -msoft-float means no float registers, while
>> > -mfp64 says there are float registers and they are 64 bits wide.
>> Well, -mhard-float and -msoft-float are ABI options. -mfp64 is
>> an architectural configuration option, and only affects calling
>> conventions when combined with -mhard-float.
> But "-mhard-float -mfp64" constitutes a new ABI variant. This is
> the case I want to cover. The "-msoft-float -mfp64" should stay
> tagged as soft float object.
Right. That's why in the other paragraph I agreed that adding a new
value to the current enumeration was the right way to go. I just don't
think GAS has enough information to generate the enumeration value itself.
> And, for completeness, we have "-mips32r2 -mips16 -mhard-float -mfp64",
> which tells the compiler to generate different stubs than the ones
> needed for the standard hard float.
Right. In theory, -mips16 supports all hard-float and soft-float ABI
combinations for o32 and o64 (including -msingle-float).