1. Poking
- Posted by Mathew Hounsell <mat.hounsell at MAILEXCITE.COM>
Sep 11, 1998
-
Last edited Sep 12, 1998
I tested some routines to see which would be the best way to wipe/fill a
character buffer.
As you can see using repeat to generate a sequence, poking it into memory and
the repeated copying produces the fastest results.
My machine 486DX2/66MHz tick_rate(100)
x 1000 * = 0.05 sec
------ ------------
0.050001 sec *--> s = repeat( c, 32 ) poke( a, s) memcopy( s
) x 8
0.050001 sec *--> s = repeat( c, 64 ) poke( a, s) memcopy( s
) x 4
0.060001 sec *--> s = repeat( c, 128 ) poke( a, s) memcopy(
s ) x 2
0.130002 sec ***--> s = repeat( c, 256 ) poke( a, s)
0.190003 sec ****-> s = {c,c,c,c} poke4( a, s ) x 64
0.320005 sec ******-> poke( a, c ) x 256
0.470007 sec *********-> poke4( a, {c,c,c,c} ) x 64
x 1000 * = 0.5 sec
------ -----------
0.240004 sec --> s = repeat( c, 320 ) poke( a, s) memcopy(
s ) x 8
0.360006 sec *--> s = repeat( c, 640 ) poke( a, s) memcopy(
s ) x 4
0.650010 sec *--> s = repeat( c, 1280 ) poke( a, s) memcopy(
s ) x 2
1.180018 sec **--> s = repeat( c, 2560 ) poke( a, s)
1.860029 sec ****--> s = {c,c,c,c} poke4( a, s ) x 640
3.160049 sec ******--> poke( a, c ) x 2560
4.720073 sec *********--> poke4( a, {c,c,c,c} ) x 640
NOTE :
for 1000 aa = a 0.000000000000000 sec
-----< Code >-----
include machine.e
sequence s
integer c
atom addr, at, at_b
atom time_then, time_a, time_t
c = '3'
tick_rate(100)
addr = allocate( 2570 )
if addr then
time_then = time()
for t = 1 to 1000 do
at = addr
end for
time_t = time() - time_then
printf(1, "for 100 aa = a %0.15f sec\n", time_t )
time_then = time()
for t = 1 to 1000 do
at = addr
at_b = addr
s = repeat(c, 320 )
poke( addr, s )
for tt = 1 to 7 do
at = at + 320
mem_copy( at, at_b, 320 )
at_b = at_b + 320
end for
end for
time_a = time() - time_then - time_t
printf(1, "s = repeat( c, 320 ) poke( a, s) memcopy( s ) x 8
%0.15f\n\n", time_a )
free( addr )
end if
-----<End Code>-----
-----
Sincerely,
Mathew Hounsell
Mat.Hounsell at Mailexcite.Com
PS : Thak you Dave for the regular expression evaluator, and thank you Ralf for
the include info, you solved one of my most annoying problems.
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