[FFmpeg-devel] [PATCH] x86: use raw opcode for xgetbv instruction
Sun Feb 20 16:43:04 CET 2011
Luca Barbato <lu_zero at gentoo.org> writes:
> On 02/20/2011 03:39 PM, Mans Rullgard wrote:
>> This allows the CPU detection to work with assemblers not supporting
>> the xgetbv mnemonic. These include clang and some BSD versions.
>> All AVX code will be written for yasm, where the main assembler
>> is not involved.
> We'd better put a notice about this somewhere and/or prepare a configure
> check in case somebody provides inline avx asm.
Note that xgetbv is not an avx instruction as such. As for inline asm,
we should discourage its use.
> The patch looks ok (given the opcode is that one).
I got it from the manual, and objdump agrees.
BTW, there is an open clang bug on this already.
mans at mansr.com
More information about the ffmpeg-devel