[FFmpeg-devel] Patch: Inline asm fixes for Intel compiler on Windows

Reimar Döffinger Reimar.Doeffinger at gmx.de
Sun Dec 29 09:31:12 CET 2013


On Sun, Dec 29, 2013 at 02:48:52PM +1100, Matt Oliver wrote:
> If using "m" is an issue with PIC then that posses a problem. I had hoped
> the compiler would be smart enough to optimise constants but I guess that
> is to much to ask.

1) Compilers are never smart enough to reliably do even the most trivial
stuff. That is basically a constant over decades of development.
2) It isn't a constant, not even if PIC is disabled, since dynamic
libraries  always must be relocatable. You could of course use the
"constant" constraint instead of "memory", but that would probably fail
even more often (it also would make the PIC issue obvious by failing
compile time, assuming you even get it to work when PIC is disabled).
Still leaves the issue with > 9 arguments.
3) It very much isn't a constant at all if PIC is enabled, especially on
32 bit x86 which is about as unsuitable for PIC as you can get.


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