|Strength reduction of constant multipliers email@example.com (1992-10-13)|
|Re: Strength reduction of constant multipliers firstname.lastname@example.org (1992-10-14)|
|multiplication by constant - quick comparison of algorithms email@example.com (Youfeng Wu) (1992-10-21)|
|Re: multiplication by constant - quick comparison of algorithms firstname.lastname@example.org (1992-10-21)|
|Re: multiplication by constant - quick comparison of algorithms email@example.com (1992-10-25)|
|Re: multiplication by constant - quick comparison of algorithms chased@rbbb.Eng.Sun.COM (1992-10-27)|
|Re: multiplication by constant - quick comparison of algorithms firstname.lastname@example.org (1992-10-28)|
|From:||Youfeng Wu <email@example.com>|
|Date:||Wed, 21 Oct 1992 06:29:44 GMT|
For all numbers in [2, 10000], there is a total number of 64612 one's in
their binary represenations, and the following compares the total number
of add/sub/shift instructions used to perform all of the multiplications.
Cliff's Bernstein (Preston Briggs)
#insts 81751 70616
Note: Cliff's algorithm generates many "shift by zero" and "add by zero"
instructions. The above numbers have already removed these nop
It should be interesting to compare them when LEA instruction is allowed.
By allowing the following LEA instructions:
LEA( b, i, s ) = b + i << s, where s = 1, 2, or 3
I have an algorithm that achieves:
The question is how we can push the ratio of #insts/
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