Dan Sugalski wrote:
[ this came up WRT calling conventions ]
I assume he's doing bsr/ret to get into and out of the sub, which is going to be significantly faster.
Who says that?
As already stated, I don't consider these as either light-weight nor faster. Here is a benchmark.
Below are 2 version of a recursive factorial program. fact(100) is calculated 1000 times:
PIR 1.1 s bsr/ret 2.4 s PIR/tailcall 0.2s
Unoptimized Parrot, default i.e. slow run core.
Way to go with the overkill. I'm impressed. However, written more sanely the results are:
PIR: real 0m4.149s user 0m4.120s sys 0m0.030s
bsr/ret: real 0m1.266s user 0m1.260s sys 0m0.000s
Chopping out the multiplication (since that's a not-insignificant amount of the runtime for the bsr/ret version) gives:
PIR: real 0m3.016s user 0m2.990s sys 0m0.030s
bsr/ret real 0m0.344s user 0m0.340s sys 0m0.010s
The bsr/ret version is:
start:
new P16, .PerlInt
set P16, 1000 elements I16, P5
lt I16, 2, def
set S0, P5[1]
set P16, S0def: set I16, 0
time N16
save N16
loop:
clone P1, P16
new P0, .PerlInt
set P0, 1
save P16
save I16
bsr fact
restore I16
restore P16
inc I16
lt I16, 1000, loop
restore N16
time N17
sub N17, N17, N16
print P0
print "\n"
print N17
print "\n"
end# in: P0 is product, p1 is count # out: P0 is new product fact: gt P1, 1, doit ret doit: mul P0, P0, P1 dec P1 bsr fact ret
--
Dan--------------------------------------it's like this-------------------
Dan Sugalski even samurai
[EMAIL PROTECTED] have teddy bears and even
teddy bears get drunk
