On the creation of temporary arrays when passing type element arguments

16

If I run the first program with gfortran on an Intel(R) Core™ i7-5500U CPU @ 2.40GHz (the time in seconds is on the right):

  • Original program (without module, without intent(in)):
$ gfortran vsrch.f90
$ time ./a.out 10000
 Found        10001      100000           5   11.4076843
  • With just a module:
$ time ./a.out 10000
 Found        10001      100000           5   11.6750689
  • With the module and the three intent(in):
$ time ./a.out 10000
 Found        10001      100000           5   4.64428234
  • With the module and the three intent(in) and -O3:
$ time ./a.out 10000    
 Found        10001      100000           5   2.95242286

It seems even a little better (~2.85-2.90) with -Os (size optimization).

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