[GHC] #5505: Program runs faster with profiling than without

[GHC]

#5505: Program runs faster with profiling than without
--------------------------------------+-------------------------------------
  Reporter:  simonpj                  |          Owner:                  
      Type:  bug                      |         Status:  new             
  Priority:  high                     |      Milestone:  7.4.1           
 Component:  Compiler                 |        Version:  7.6.1           
Resolution:                           |       Keywords:                  
        Os:  Windows                  |   Architecture:  Unknown/Multiple
   Failure:  Runtime performance bug  |     Difficulty:                  
  Testcase:                           |      Blockedby:                  
  Blocking:                           |        Related:                  
--------------------------------------+-------------------------------------

Comment(by tomberek):

 {{{
 ./Main.exe +RTS -s
 222
 CPU time:   1.87s
          172,636 bytes allocated in the heap
              980 bytes copied during GC
           41,860 bytes maximum residency (1 sample(s))
           19,580 bytes maximum slop
                1 MB total memory in use (0 MB lost due to fragmentation)

                                     Tot time (elapsed)  Avg pause  Max
 pause
   Gen  0         0 colls,     0 par    0.00s    0.00s     0.0000s
 0.0000s
   Gen  1         1 colls,     0 par    0.00s    0.00s     0.0001s
 0.0001s

   INIT    time    0.00s  (  0.00s elapsed)
   MUT     time    1.87s  (  1.86s elapsed)
   GC      time    0.00s  (  0.00s elapsed)
   EXIT    time    0.00s  (  0.00s elapsed)
   Total   time    1.87s  (  1.86s elapsed)

   %GC     time       0.0%  (0.0% elapsed)

   Alloc rate    92,219 bytes per MUT second

   Productivity 100.0% of total user, 100.6% of total elapsed


 ./Main.exe +RTS -s -h
 222
 CPU time:   1.39s
          172,892 bytes allocated in the heap
          271,180 bytes copied during GC
           78,104 bytes maximum residency (14 sample(s))
           20,200 bytes maximum slop
                1 MB total memory in use (0 MB lost due to fragmentation)

                                     Tot time (elapsed)  Avg pause  Max
 pause
   Gen  0         0 colls,     0 par    0.00s    0.00s     0.0000s
 0.0000s
   Gen  1        14 colls,     0 par    0.00s    0.00s     0.0002s
 0.0003s

   INIT    time    0.00s  (  0.00s elapsed)
   MUT     time    1.39s  (  1.37s elapsed)
   GC      time    0.00s  (  0.00s elapsed)
   EXIT    time    0.00s  (  0.00s elapsed)
   Total   time    1.39s  (  1.38s elapsed)

   %GC     time       0.0%  (0.2% elapsed)

   Alloc rate    124,525 bytes per MUT second

   Productivity 100.0% of total user, 100.7% of total elapsed
 }}}

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/5505#comment:14>
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