Re: 387 emulator hack - mutant AAD trick - any objections?

From: Denis Vlasenko
Date: Fri May 27 2005 - 04:46:01 EST


On Friday 27 May 2005 10:44, cutaway@xxxxxxxxxxxxx wrote:
> Brain fade...example should be:
>
> 1) Start with AX = 0x0023
> 2) Execute AAM instruction
> 3) Now AX = 0x0305 (unpacked BCD)
> 4) Execute base 16 AAD instruction
> 5) Now AX = 0x0035 (packed BCD)

Intel syntax:

shl ah,4
or al,ah
mov ah,0 (if needed)

No need to use AAD16, it is
a) doesnt work on some obscure ancient NEC x86 clones IIRC
b) is microcoded (slow)
--
vda

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