1 |
Stroller<stroller@××××××××××××××××××.uk> writes: |
2 |
> But, surely "-march=" also instructs gcc to support the additional |
3 |
> instructions. Suggest you re-read Daniel's post that I was replying |
4 |
> to. |
5 |
> |
6 |
> What's the difference between supporting the "certain set of |
7 |
> instructions" with "-march=" and doing so with USEs? |
8 |
|
9 |
One is for telling gcc how to compile C code, the other is for telling |
10 |
packages what inline assembler code is legal. |
11 |
|
12 |
In the case of mplayer, just setting mmx/sse/etc does absolutely |
13 |
nothing. You also have to enable custom-cpuopts, which then tells |
14 |
mplayer to ignore its own build-time detection of CPU features and only |
15 |
use the ones you tell it. Either way, if mplayer does it automatically |
16 |
or you pass in USE flags, all they do is enable selected asm files in |
17 |
the codecs that use those opcodes. |
18 |
|
19 |
--K |