[Ffmpeg-devel] Re: [PATCH] Fix compilation when using --disable-opts

[Måns Rullgård]

"Alexis Ballier" <alexis.ballier at gmail.com> writes:

>> Yes 7 registers are assumed on AMD64. And there will be 7 registers
>> available because there are more registers than on 32-bit so it doesn't
>> matter even if one is reserved.
>> This error has nothing whatsoever to do with the number of available
>> registers, and is not the one mentioned in the first link you gave in
>> your original post.
>>
>> So there are 2 separate problems:
>>
>> error: PIC register '%ebx' clobbered in 'asm'
>> This is the one first linked to in your original mail, and is related to
>> CONFIG_7REGS.
>>
>> Error: junk `(%rip)' after expression
>> This has nothing to do with CONFIG_7REGS. Reimar's earlier post talked
>> about this problem.

[...]

> A possible fix would be to readd the hack that wouldnt use ebx with
> pic and __GNUC__ defined, but I dunno if this is wanted.
> A probably better one would be to add a check for ebx with pic in
> configure with something like  :
>
> #ifdef PIC
> test ebx
> #endif
>
> compiled with -fPIC (or with a more portable way) and with
> -D$LIBOBJFLAGS (the syntax is wrong but you get the idea) so that it
> would be a "generic" check for ebx with pic without requiring special
> ifdef's for gcc (and then update the if defined logic to reflect that)

We always test the availability of ebx and ebp, PIC or not.

-- 
M?ns Rullg?rd
mans at mansr.com