Re: [patch 5/8] Immediate Values - x86 Optimization (update)

[H. Peter Anvin]

Mathieu Desnoyers wrote:
> Ok, so the most flexible solution that I see, that should fit for both
> i386 and x86_64 would be :
>
>
> 1 byte  : "=Q" : Any register accessible as rh: a, b, c, and d.
> 2, 4 bytes : "=R" : Legacy registerâthe eight integer registers available
>                  on all i386 processors (a, b, c, d, si, di, bp, sp). 
> 8 bytes : (only for x86_64)
>           "=r" : A register operand is allowed provided that it is in a
>                  general register.
>
> That should make sure x86_64 won't try to use REX prefixed opcodes for
> 1, 2 and 4 bytes values.
>
> Does it make sense ?

That's probably the best bet.

	-hpa
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