[MSX] MAP update, 2005-05-12
lholst at students.cs.uu.nl
Fri May 13 00:54:49 CEST 2005
Patriek Lesparre wrote:
>> * Replaced the Div16 16-bits division routine with a faster one by
>> Flyguille. The speed gain seems quite humble, 3 T-states, but this one
>> can be unrolled to gain quite some speed.
> Another 4 t-states can be saved by replacing
> XOR A ; 5 t-states
> LD L,A ; 5 t-states
> LD H,A ; 5 t-states
> LD HL,0 ; 11 t-states
> The first sequence of instructions are only faster if both A and HL are
> supposed to be 0, which is not the case in this routine.
Thanks! Though it’s only 3 states, as I’m also counting the additional
M1 wait state. If you don’t mind, I’ll just keep the credit for you on
this list, otherwise the document’ll become a maze of thanks this thanks
that ^_^. Even though the tweak effectively doubles the gain in speed ;)
Ushiko-san! Kimi wa doushite, Ushiko-san!!
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