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Alternative ways to divide and multiply with assembly.

Martyr · 2004-08-05 18:27:32

I use these instructions instead of using IMUL or MUL sometimes to speed up code when i know number. Multiplying EAX by 3. [PHP]lea eax, [eax + 2 * eax][/PHP] By 24 [PHP]lea eax, [eax + 2 * eax] shl eax, 3[/PHP] And so on..are there alternative ways to divide also, without using DIV & IDIV instructions???

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05-08-2004 7:27pm

#1

Martyr

Closed Accounts Posts: 1,567 ✭✭✭

Join Date: November 2001

Posts: 1391

I use these instructions instead of using IMUL or MUL sometimes
to speed up code when i know number.

Multiplying EAX by 3.

[PHP]lea eax, [eax + 2 * eax][/PHP]

By 24

[PHP]lea eax, [eax + 2 * eax]
shl eax, 3[/PHP]

And so on..are there alternative ways to divide also, without using DIV & IDIV
instructions???

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