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assemblyforthsquare-root

Square root function in Forth using x86 Assembly?

I don't know much about assembly, but I am pretty sure that there are square root instructions on the x86? I am trying to get a square root function to work well in froth and the one that I have found gets bogged down somehow when I run it many times.

: sqrt-closer ( square guess -- square guess adjustment)
2dup / over - 2 /
;

: sqrt ( square -- root )
1 begin
sqrt-closer dup
while + repeat
drop nip ;
Solution

  • There is a floating-point square root instruction (FSQRT). This is quite fast, even if you only need an integer square root.