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From: "mehdi.chinoune at hotmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug fortran/98577] Wrong "count_rate" values with int32 and real32 if the "count" argument is int64.
Date: Thu, 07 Jan 2021 13:03:21 +0000 [thread overview]
Message-ID: <bug-98577-4-zEDul7nPQu@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-98577-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98577
Chinoune <mehdi.chinoune at hotmail dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|RESOLVED |UNCONFIRMED
Resolution|INVALID |---
--- Comment #2 from Chinoune <mehdi.chinoune at hotmail dot com> ---
program main
use iso_fortran_env
implicit none
!
integer(int32) :: count_rate_i32
integer(int64) :: t1, t2, t3, t4, t5, t6
real(real32) :: count_rate_r32
real(real64) :: count_rate_r64
!
integer(int32), parameter :: n = 2048
real(real64), allocatable :: a(:,:), b(:,:), c(:,:)
integer :: i, j, k
!
allocate( a(n,n), b(n,n), c(n,n) )
call random_number( a )
call random_number( b )
!
call system_clock( t1, count_rate_r32 )
c = matmul( a, b )
call system_clock( t2 )
!
call system_clock( t3, count_rate_i32 )
b = matmul( c, a )
call system_clock( t4 )
!
call system_clock( t5, count_rate_r64 )
a = matmul( b, c )
call system_clock( t6 )
!
print*, "count_rate_r32:", (t2-t1)/count_rate_r32
print*, "count_rate_i32:", (t4-t3)/real(count_rate_i32,real64)
print*, "count_rate_r64:", (t6-t5)/count_rate_r64
!
end program main
$ gfortran-9 -O3 bug_gcc_98577_2.f90 -o test.x
$ ./test.x
count_rate_r32: 478419744.
count_rate_i32:
479128968.57999998
count_rate_r64: 0.71684850000000000
$ gfortran-10 -O3 bug_gcc_98577_2.f90 -o test.x
$ ./test.x
count_rate_r32: 568052096.
count_rate_i32:
568763156.84800005
count_rate_r64: 0.71658250000000001
Can you explain these results?!
next prev parent reply other threads:[~2021-01-07 13:03 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-07 4:12 [Bug fortran/98577] New: " mehdi.chinoune at hotmail dot com
2021-01-07 11:36 ` [Bug fortran/98577] " anlauf at gcc dot gnu.org
2021-01-07 13:03 ` mehdi.chinoune at hotmail dot com [this message]
2021-01-07 16:32 ` kargl at gcc dot gnu.org
2021-01-07 17:28 ` mehdi.chinoune at hotmail dot com
2021-01-07 18:01 ` sgk at troutmask dot apl.washington.edu
2021-01-07 18:49 ` mehdi.chinoune at hotmail dot com
2021-01-07 18:56 ` mehdi.chinoune at hotmail dot com
2021-01-07 20:27 ` sgk at troutmask dot apl.washington.edu
2021-01-07 20:37 ` kargl at gcc dot gnu.org
2021-01-08 6:18 ` mehdi.chinoune at hotmail dot com
2021-01-08 7:21 ` kargl at gcc dot gnu.org
2021-01-08 8:04 ` mehdi.chinoune at hotmail dot com
2021-01-08 8:27 ` mehdi.chinoune at hotmail dot com
2021-01-08 16:12 ` kargl at gcc dot gnu.org
2021-01-08 16:42 ` mehdi.chinoune at hotmail dot com
2021-01-08 16:59 ` kargl at gcc dot gnu.org
2021-01-08 18:43 ` mehdi.chinoune at hotmail dot com
2021-01-08 18:55 ` sgk at troutmask dot apl.washington.edu
2021-01-08 19:19 ` sgk at troutmask dot apl.washington.edu
2021-01-09 2:34 ` mehdi.chinoune at hotmail dot com
2021-01-09 3:43 ` kargl at gcc dot gnu.org
2021-01-09 9:00 ` tkoenig at gcc dot gnu.org
2023-05-14 16:01 ` mehdi.chinoune at hotmail dot com
2023-05-14 16:37 ` tkoenig at gcc dot gnu.org
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