I repeated the profiling: print $ sumCheck 500 [1..1000] [1..1000] sumCheck1: 58,648 sumCheck2: 58,484 sumCheck3: 70,016 print $ sumCheck 5000 [1..10000] [1..10000] sumCheck1: 238,668 sumCheck2: 238,504 sumCheck3: 358,016 (unit: byte) This time I used the same compiler flags as Aditya (all but -rtsopts, I got:ghc: unrecognised flags: -rtsopts ). I'm using GHC version 6.12.1. Ok, in this numerical example, the scaling of sumCheck3 is not worse than the other's. In my first run I used quasi random numbers (fingers on my keyboard). Maybe you got puzzled with your '.prof' files? They seem identical (there always exists a function sum) On 07/27/2011 07:34 AM, aditya siram wrote:
I just profiled all three and have not found them to be different. Maybe I'm reading my profiler output wrong so I've pasted it below. The compilation command I used was: ghc -fforce-recomp -XBangPatterns -prof -rtsopts -auto-all -o ListCrossProductSum ListCrossProductSum.hs
They were all invoked using: main = print $ sumCheck 5000 [1..10000] [1..10000]
I am running GHC 7.0.1
-deech
sumcheck1: ========== Wed Jul 27 00:26 2011 Time and Allocation Profiling Report (Final)
ListCrossProductSum +RTS -p -RTS
total time = 0.00 secs (0 ticks @ 20 ms) total alloc = 344,084 bytes (excludes profiling overheads)
COST CENTRE MODULE %time %alloc
sums Main 0.0 40.7 main Main 0.0 58.3
individual inherited COST CENTRE MODULE no. entries %time %alloc %time %alloc
MAIN MAIN 1 0 0.0 0.0 0.0 100.0 CAF Main 240 2 0.0 0.2 0.0 99.2 main Main 246 1 0.0 58.3 0.0 99.0 sumCheck Main 247 1 0.0 0.0 0.0 40.7 sums Main 248 1 0.0 40.7 0.0 40.7 CAF GHC.Show 236 1 0.0 0.0 0.0 0.0 CAF GHC.IO.Handle.FD 176 2 0.0 0.4 0.0 0.4 CAF System.Posix.Internals 175 1 0.0 0.0 0.0 0.0 CAF GHC.IO.Handle.Internals 140 1 0.0 0.0 0.0 0.0 CAF GHC.IO.Encoding.Iconv 134 2 0.0 0.3 0.0 0.3 CAF GHC.Conc.Signal 131 1 0.0 0.1 0.0 0.1
sumcheck2 ========= [1 of 1] Compiling Main ( ListCrossProductSum.hs, ListCrossProductSum.o ) True Wed Jul 27 00:27 2011 Time and Allocation Profiling Report (Final)
ListCrossProductSum +RTS -p -RTS
total time = 0.00 secs (0 ticks @ 20 ms) total alloc = 344,084 bytes (excludes profiling overheads)
COST CENTRE MODULE %time %alloc
sums Main 0.0 40.7 main Main 0.0 58.3
individual inherited COST CENTRE MODULE no. entries %time %alloc %time %alloc
MAIN MAIN 1 0 0.0 0.0 0.0 100.0 CAF Main 240 2 0.0 0.2 0.0 99.2 main Main 246 1 0.0 58.3 0.0 99.0 sumCheck Main 247 1 0.0 0.0 0.0 40.7 sums Main 248 1 0.0 40.7 0.0 40.7 CAF GHC.Show 236 1 0.0 0.0 0.0 0.0 CAF GHC.IO.Handle.FD 176 2 0.0 0.4 0.0 0.4 CAF System.Posix.Internals 175 1 0.0 0.0 0.0 0.0 CAF GHC.IO.Handle.Internals 140 1 0.0 0.0 0.0 0.0 CAF GHC.IO.Encoding.Iconv 134 2 0.0 0.3 0.0 0.3 CAF GHC.Conc.Signal 131 1 0.0 0.1 0.0 0.1
sumcheck3 ========= ListCrossProductSum +RTS -p -RTS
total time = 0.00 secs (0 ticks @ 20 ms) total alloc = 344,084 bytes (excludes profiling overheads)
COST CENTRE MODULE %time %alloc
sums Main 0.0 40.7 main Main 0.0 58.3
individual inherited COST CENTRE MODULE no. entries %time %alloc %time %alloc
MAIN MAIN 1 0 0.0 0.0 0.0 100.0 CAF Main 240 2 0.0 0.2 0.0 99.2 main Main 246 1 0.0 58.3 0.0 99.0 sumCheck Main 247 1 0.0 0.0 0.0 40.7 sums Main 248 1 0.0 40.7 0.0 40.7 CAF GHC.Show 236 1 0.0 0.0 0.0 0.0 CAF GHC.IO.Handle.FD 176 2 0.0 0.4 0.0 0.4 CAF System.Posix.Internals 175 1 0.0 0.0 0.0 0.0 CAF GHC.IO.Handle.Internals 140 1 0.0 0.0 0.0 0.0 CAF GHC.IO.Encoding.Iconv 134 2 0.0 0.3 0.0 0.3 CAF GHC.Conc.Signal 131 1 0.0 0.1 0.0 0.1