[FFmpeg-devel] [PATCH 1/2] x86inc: Extend FMA_INSTR functionality

[James Almer]

On 14/02/14 5:57 AM, Christophe Gisquet wrote:
> 2014-02-13 James Almer <jamrial at gmail.com>:
>> You're right, a fifth parameter is probably the proper way. See
>> FMULADD_PS in x86util. It would allow actual non-destructive emulation
>> of these XOP instructions if it's ever needed.
>> It's not for now, but changing it will not hurt and it will probably have
>> to be done at some point anyway.
> 
> You can probably make it optional (haven't looked at FMULADD_PS), ie
> make the macro use 4-8 arguments, and if %0 == 8, use %8, otherwise
> use %2.
> 

Someone else committed the opposite to x264, making the %1 = %2 * %3 + %1 case 
unsupported instead, so I'm not sure at this point if this should be on x86inc 
or added as a local macro on a given asm file like i originally did.