About fpr usage in mips64

[Heiher]

Thank you reply!

I want to use ICT Loongson 3A extension SIMD instructions in o32 ABI
program. The march loongson3a is based on mips64. -mfp32 don't work...
:(

On Wed, Nov 30, 2011 at 2:42 PM, Ian Lance Taylor <iant@google.com> wrote:
> Heiher <admin@heiher.info> writes:
>
>> The o32 abi programs could only use even-numbered floating-point
>> registers by appointment. The GCC generate assembly source  code using
>> odd-numbered floating-point register when I -march=mips64 and
>> -mabi=32. Every double floating-point instructions will use 32-bit
>> even/odd-numbered paired 64-bit fpr when 0 = bit FR in Status
>> register. However kernel set bit FR to a thread at loading ELF for N32
>> or 64 only. In other words, o32 abi process can't use odd-numbered
>> fpr.
>>
>> How ought I to act? Thanks!
>
> I'm not sure it makes sense to use -march=mips64 -mabi=32.  Why do you
> want to do that?
>
> You could try using the -mfp32 option but I don't know whether it will
> help.
>
> Ian



-- 
Best regards!
Heiher