Re: Replacing $mon with Jan, Feb, Mar by regex or other means

To make a better comparison, you should strftimeLookup do a getMonthNumber as well. Now it's the only case that isn't penalized by an extra subroutine call. Or you could eliminate the call from all cases, the lookup time won't be different depending on the number of the month. Just use a fixed month number (but don't hardcode it as a literal, or else the compiler might pre-calculate some calculations).

Abigail

Comment on Re: Replacing $mon with Jan, Feb, Mar by regex or other means Select or Download Code

Replies are listed 'Best First'.
Re: Re: Replacing $mon with Jan, Feb, Mar by regex or other means by RMGir (Prior) on Apr 25, 2003 at 12:14 UTC
I did consider that, but since the strftime variant was already losing badly, it didn't seem critical. You're right, though, wrapping the fetch of @fixedLocaltime in a sub (returning a ref to the array) call kills the performance of the strftime variant a bit more. $ perl testMonth.pl Benchmark: running inlineArrayLookup, preBuiltArrayLookup, strftimeLoo +kup, strftimeSubLookup, substrLookup, each for at least 2 CPU seconds +... inlineArrayLookup: 2 wallclock secs ( 2.12 usr + 0.00 sys = 2.12 CP +U) @ 513847.17/s (n=1089356) preBuiltArrayLookup: 2 wallclock secs ( 2.09 usr + 0.01 sys = 2.10 +CPU) @ 568700.00/s (n=1194270) strftimeLookup: 1 wallclock secs ( 1.81 usr + 0.35 sys = 2.16 CPU) +@ 223003.24/s (n=481687) strftimeSubLookup: 2 wallclock secs ( 1.74 usr + 0.26 sys = 2.00 CP +U) @ 182455.50/s (n=364911) substrLookup: 2 wallclock secs ( 2.19 usr + 0.01 sys = 2.20 CPU) @ +446835.91/s (n=983039) Rate strftimeSubLookup strftimeLookup substrLo +okup inlineArrayLookup preBuiltArrayLookup strftimeSubLookup 182455/s -- -18% +-59% -64% -68% strftimeLookup 223003/s 22% -- +-50% -57% -61% substrLookup 446836/s 145% 100% + -- -13% -21% inlineArrayLookup 513847/s 182% 130% + 15% -- -10% preBuiltArrayLookup 568700/s 212% 155% + 27% 11% -- [download] -- Mike Edit by tye, change PRE to CODE around long lines	[reply] [d/l]

Replies are listed 'Best First'.

Re: Re: Replacing $mon with Jan, Feb, Mar by regex or other means
by RMGir (Prior) on Apr 25, 2003 at 12:14 UTC

You're right, though, wrapping the fetch of @fixedLocaltime in a sub (returning a ref to the array) call kills the performance of the strftime variant a bit more.

$ perl testMonth.pl 
Benchmark: running inlineArrayLookup, preBuiltArrayLookup, strftimeLoo
+kup, strftimeSubLookup, substrLookup, each for at least 2 CPU seconds
+...
inlineArrayLookup:  2 wallclock secs ( 2.12 usr +  0.00 sys =  2.12 CP
+U) @ 513847.17/s (n=1089356)
preBuiltArrayLookup:  2 wallclock secs ( 2.09 usr +  0.01 sys =  2.10 
+CPU) @ 568700.00/s (n=1194270)
strftimeLookup:  1 wallclock secs ( 1.81 usr +  0.35 sys =  2.16 CPU) 
+@ 223003.24/s (n=481687)
strftimeSubLookup:  2 wallclock secs ( 1.74 usr +  0.26 sys =  2.00 CP
+U) @ 182455.50/s (n=364911)
substrLookup:  2 wallclock secs ( 2.19 usr +  0.01 sys =  2.20 CPU) @ 
+446835.91/s (n=983039)
                        Rate strftimeSubLookup strftimeLookup substrLo
+okup inlineArrayLookup preBuiltArrayLookup
strftimeSubLookup   182455/s                --           -18%         
+-59%              -64%                -68%
strftimeLookup      223003/s               22%             --         
+-50%              -57%                -61%
substrLookup        446836/s              145%           100%         
+  --              -13%                -21%
inlineArrayLookup   513847/s              182%           130%         
+ 15%                --                -10%
preBuiltArrayLookup 568700/s              212%           155%         
+ 27%               11%                  --
[download]

Edit by tye, change PRE to CODE around long lines

[reply]
[d/l]