quantum-espresso/Modules/random_numbers_gpu.f90

151 lines
4.7 KiB
Fortran

!
! Copyright (C) 2001-2012 Quantum ESPRESSO group
! This file is distributed under the terms of the
! GNU General Public License. See the file `License'
! in the root directory of the present distribution,
! or http://www.gnu.org/copyleft/gpl.txt .
!
!----------------------------------------------------------------------------
MODULE random_numbers_gpum
!----------------------------------------------------------------------------
!! Module for random numbers generation - GPU double.
!
USE kinds, ONLY : DP
#if defined(__CUDA)
USE cudafor
#endif
!
IMPLICIT NONE
!
CONTAINS
!
!------------------------------------------------------------------------
FUNCTION randy_gpu ( irand )
!------------------------------------------------------------------------
REAL(DP) :: randy_gpu
INTEGER, optional :: irand
#if defined(__CUDA)
attributes(DEVICE) :: randy_gpu
#endif
call errore('randy','use randy_vect_gpu on GPUs',1)
END FUNCTION randy_gpu
!------------------------------------------------------------------------
SUBROUTINE randy_vect_gpu ( r_d, n, irand )
!------------------------------------------------------------------------
!
! randy_vect_gpu(r, n, irand): reseed with initial seed idum=irand ( 0 <= irand <= ic, see below)
! if randyv is not explicitly initialized, it will be
! initialized with seed idum=0 the first time it is called
! randy_vect_gpu(r, n) : generate uniform real(DP) numbers x in [0,1]
!
USE random_numbers, ONLY : randy
#if defined(__CUDA)
USE curand
#endif
REAL(DP) :: r_d(n)
#if defined(__CUDA)
attributes(DEVICE) :: r_d
#endif
INTEGER :: i, n
INTEGER, optional :: irand
!
INTEGER :: ist
INTEGER, SAVE :: idum=0
#if defined(__CUDA)
type(curandGenerator), SAVE :: gen
LOGICAL, SAVE :: first=.true.
!
IF ( present(irand) ) THEN
idum = MIN( ABS(irand), idum)
first=.true.
END IF
!
IF ( first ) THEN
!
first = .false.
ist=curandDestroyGenerator(gen)
ist=curandCreateGenerator(gen, CURAND_RNG_PSEUDO_XORWOW) ! or CURAND_RNG_PSEUDO_MRG32k3a
ist=curandSetPseudoRandomGeneratorSeed(gen, idum)
!
END IF
!
ist=curandGenerateUniformDouble(gen,r_d,n)
!
#else
! randy_vect_gpu is not a GPU array in this case
!
! ist means starting index here
ist = 1
IF ( present(irand) ) THEN
r_d(1) = randy(irand)
ist = 2
END IF
DO i = ist, n
r_d(i) = randy()
END DO
#endif
RETURN
!
END SUBROUTINE randy_vect_gpu
!
!------------------------------------------------------------------------
SUBROUTINE randy_vect_debug_gpu (r_d, n, irand )
!------------------------------------------------------------------------
!
! randy_vect_debug_gpu(r, n, irand): reseed with initial seed idum=irand ( 0 <= irand <= ic, see below)
! if randyv is not explicitly initialized, it will be
! initialized with seed idum=0 the first time it is called
! randy_vect_debug_gpu(r, n) : generate uniform real(DP) numbers x in [0,1]
!
USE random_numbers, ONLY : randy
!
REAL(DP) :: r_d(n)
INTEGER, optional :: irand
#if defined(__CUDA)
attributes(DEVICE) :: r_d
#endif
INTEGER :: n, i, ist
REAL(DP), ALLOCATABLE :: aux_v(:)
!
ALLOCATE(aux_v(n))
!
ist = 1
IF ( present(irand) ) THEN
aux_v(1) = randy(irand)
ist = 2
END IF
!
DO i = ist, n
aux_v(i) = randy()
END DO
!
r_d(1:n) = aux_v(1:n)
!
DEALLOCATE(aux_v)
END SUBROUTINE randy_vect_debug_gpu
!
!------------------------------------------------------------------------
SUBROUTINE set_random_seed ( )
!------------------------------------------------------------------------
!
! poor-man random seed for randy
!
INTEGER, DIMENSION (8) :: itime
INTEGER :: iseed
REAL(DP) :: drand(1)
#if defined(__CUDA)
attributes(DEVICE) :: drand
#endif
!
CALL date_and_time ( values = itime )
! itime contains: year, month, day, time difference in minutes, hours,
! minutes, seconds and milliseconds.
iseed = ( itime(8) + itime(6) ) * ( itime(7) + itime(4) )
CALL randy_vect_gpu ( drand, 1, iseed )
CALL randy_vect_debug_gpu (drand, 1, iseed )
!
END SUBROUTINE set_random_seed
!
END MODULE random_numbers_gpum