Re: Skybuck presents Faster Div 7

Also here is a litte bit faster version:

// little bit faster
function SimulatedDiv7v5( Content : longword ) : longword; inline;
var
 vEightDivisions : longword;
begin
 result := 0;  // latency 1

// vLoops := 0;

 while Content > 8 do // latency 1 + latency 1 = latency 2
 begin
  vEightDivisions := (Content shr 3); // latency 1 + latency 1 = latency 2
  Content := (Content and 7) + vEightDivisions; // latency 1 + latency 1 =

latency 2
  result := result + vEightDivisions; // latency 1
 end;

 // single loop latency: 2 + 2 + 2 + 1 = 7

 if Content >= 7 then // latency 1 + latency 1 = latency 2
 begin
  result := result + 1; // latency 1
 end;

 // best case latency: 1 + 7 + 3 = 11
 // worst case latency (max loops 11 for 32 bit longwords): 1 + 7 * 11 + 3
= 
81

 // very close to div 7, though this routine is probably directpath mostly

and not vector path
 // so maybe it's faster... but then again still some calling overhead.. 
let's see what happens
 // when it's inlined ;)
 // yup inlining works real nice.

 // time for a benchmark :)

 // tested on amd x2 3800+
 // for content values ranging from say 1000 to even a million this
routine 
appears
 // to be faster than the div... kinda nice.

end;