Potential issue with --enable-fat

[Niels Möller]

Marc Glisse <marc.glisse at inria.fr> writes:

> On Mon, 10 Feb 2025, Niels Möller wrote:
>
>> diff -r 1a2ad0e32507 configure.ac
>> --- a/configure.ac	Mon Feb 03 17:52:54 2025 +0100
>> +++ b/configure.ac	Mon Feb 10 16:21:35 2025 +0100
>> @@ -3843,7 +3843,9 @@ yes
>>     X86_PATTERN | X86_64_PATTERN)
>>       GMP_ASM_ALIGN_FILL_0x90
>>       if test "$x86_have_mulx" = yes; then
>> -        GMP_ASM_X86_MULX
>> +        if test "$enable_fat" = no; then
>> +	  GMP_ASM_X86_MULX
>> +	fi
>>       fi
>>       GMP_ASM_COFF_TYPE
>>       case $ABI in
>
> I don't like it, GMP_ASM_X86_MULX is about the assembler supporting
> the mulx instruction, not about the host processor being able to
> execute it.

That's what the docs say, but as far as I see, it is used *only* for
controlling the inline asm in longlong.h.

Which is a bit puzzling: it would make sense if it also controls if
mpn/x86_64/mulx is added to the asm path, but I don't see how that
happens?

I think it would make thigs a bit clearer to take out
AC_DEFINE(X86_ASM_MULX, ...) from GMP_ASM_X86_MULX, and instead let the
IF-YES path in configure.ac arrange so that the right things happen, for
both fat and non-fat builds.

Regards,
/Niels

-- 
Niels Möller. PGP key CB4962D070D77D7FCB8BA36271D8F1FF368C6677.
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