[FFmpeg-devel] [RFC] fix AMD64 OpenBSD 4.7 compilation

[Reimar Döffinger]

On Sat, Aug 21, 2010 at 12:31:15AM -0400, David Conrad wrote:
> On Aug 20, 2010, at 1:33 PM, Reimar D?ffinger wrote:
> 
> > Hello,
> > newer binutils are very lenient, accepting e.g. eax as register for
> > addressing (which means silently substituting it by rax, since eax can't
> > be used for addresses).
> 
> It's not binutils being lenient; addressing with 32-bit registers is distinct from using 64-bit registers (it uses the 0x67 prefix.) If openbsd's binutils doesn't accept addressing using 32-bit registers it's buggy.

I somehow missed that existed...
It's still a bit of a waste of bytes, since it could use the 64 bit registers.

> But the usage in cabac seem buggy anyway since there's no guarantee that the table addresses will be in the lower 32 bits.

The e* registers are not used for any addresses, only for offsets.
Unless using the 0x67 prefix means using 32 bit addresses, not only
32 bit registers for the offsets...