basic time-measuring loop

1 files changed, 35 insertions, 31 deletions

diff --git a/src/main.F90 b/src/main.F90
index f898e1a..2649e10 100644
--- a/src/main.F90
+++ b/src/main.F90
@@ -4,42 +4,46 @@ PROGRAM mul
   USE dotmat
   IMPLICIT none
 
-  real(kind=4), dimension(:,:), allocatable :: mat1, mat2, res1, res2
-
-  call init_random_seed()
-
-  allocate(mat1(10,10))
-  allocate(mat2(10,10))
-  allocate(res1(10,10))
-  allocate(res2(10,10))
-
-  call random_number(mat1)
-  call random_number(mat2)
-  
-  print *, "mat1:", char(10), mat1
-  print *, "mat2:", char(10), mat2
-  
-  res1 = naivmull(mat1, mat2)
-  res2 = matmul(mat1, mat2)
-
-  print *, "res:", char(10), res1
-  print *, "res_diff:", char(10), res1 - res2
-  
+  real(kind=4), dimension(:,:), allocatable :: mat1, mat2, res
+  real :: start, end
+  integer :: dim = 10
+
+  DO WHILE (dim < 2000)
+     
+     call init_random_seed(123456)
+
+     allocate(mat1(dim,dim))
+     allocate(mat2(dim,dim))
+     allocate(res(dim,dim))
+
+     call random_number(mat1)
+     call random_number(mat2)
+
+     call cpu_time(start)
+
+     res = naivmull(mat1, mat2)
+
+     call cpu_time(end)
+
+     print '(I11," ",ES11.5)', dim, end - start
+
+     dim = dim * 2
+
+     deallocate(mat1)
+     deallocate(mat2)
+     deallocate(res)
+     
+  END DO
+
 CONTAINS
 
-  SUBROUTINE init_random_seed()
-    integer :: i, n, clock
-    integer, dimension(:), allocatable :: seed
+  SUBROUTINE init_random_seed(seed)
+    integer, intent(in) :: seed
+    integer :: i, n
     
     call random_seed(size = n)
     
-    allocate(seed(n))
-    
-    call system_clock(count = clock)
-    
-    seed = clock + 37 * (/ (i - 1, i = 1, n) /)
-    
-    call random_seed(put = seed)
+    call random_seed(put = (/ ((seed + i) * 37, i = 1, n) /))
     
   END SUBROUTINE init_random_seed