Juan 27/08/2021:dotprod.f90, add orig for GPU opti

src/ZSOLVER/dotprod.f90

+!MNH_LIC Copyright 1994-2014 CNRS, Meteo-France and Universite Paul Sabatier
+!MNH_LIC This is part of the Meso-NH software governed by the CeCILL-C licence
+!MNH_LIC version 1. See LICENSE, CeCILL-C_V1-en.txt and CeCILL-C_V1-fr.txt  
+!MNH_LIC for details. version 1.
+!-----------------------------------------------------------------
+!--------------- special set of characters for RCS information
+!-----------------------------------------------------------------
+! $Source$ $Revision$
+! MASDEV4_7 solver 2006/05/18 13:07:25
+!-----------------------------------------------------------------
+!     ###################
+      MODULE MODI_DOTPROD
+!     ###################
+!
+INTERFACE
+!
+      FUNCTION DOTPROD(PA,PB,HLBCX,HLBCY)  RESULT(PDOTPROD)
+!  
+IMPLICIT NONE
+!
+REAL, DIMENSION(:,:,:), INTENT(IN) :: PA, PB     ! input vectors
+!
+CHARACTER (LEN=4), DIMENSION(2), INTENT(IN) :: HLBCX    ! x-direction LBC type 
+CHARACTER (LEN=4), DIMENSION(2), INTENT(IN) :: HLBCY    ! y-direction LBC type 
+!
+REAL :: PDOTPROD                                     ! dot product
+!
+END FUNCTION DOTPROD
+!
+END INTERFACE
+!
+END MODULE MODI_DOTPROD
+!
+!
+!
+!     #####################################################
+      FUNCTION DOTPROD(PA,PB,HLBCX,HLBCY)  RESULT(PDOTPROD)
+!     #####################################################
+!
+!!****  *DOTPROD* -  compute the dot product of two vectors
+!!
+!!    PURPOSE
+!!    -------
+!       The purpose of this function  is to compute dot product of the vectors 
+!     stored in the arrays PA, PB. The elements of PA and PB are localized at
+!     mass points.
+!
+!!**  METHOD
+!!    ------ 
+!!      The scalar product DOTPROD  of 2 vectors  A and B is defined by : 
+!!        DOTPROD = SUM( A(i,j,k)* B(i,j,k) )
+!!    The bounds for the summation depend on the l.b.c.
+!!
+!!    EXTERNAL
+!!    --------
+!!      NONE
+!!
+!!    IMPLICIT ARGUMENTS
+!!    ------------------
+!!      Module MODD_PARAMETERS: declaration of parameter variables
+!!        JPHEXT, JPVEXT: define the number of marginal points out of the 
+!!        physical domain along horizontal and vertical directions respectively
+!!     Module MODD_CONF: model configurations
+!!        L2D: logical switch for 2D model version
+!!
+!!    REFERENCE
+!!    ---------
+!!      Book2 of documentation of Meso-NH (function DOTPROD)
+!!
+!!    AUTHOR
+!!    ------
+!!	P. Hereil and J. Stein      * Meteo France *
+!!
+!!    MODIFICATIONS
+!!    -------------
+!!      Original    25/07/94 
+!!      J.-P. Pinty 12/11/99 Parallelization
+!!
+!-------------------------------------------------------------------------------
+!
+!*      0.     DECLARATIONS
+!              ------------
+!
+USE MODD_PARAMETERS
+USE MODD_CONF
+!
+USE MODE_ll
+!JUAN
+USE MODE_REPRO_SUM
+!JUAN
+!
+IMPLICIT NONE
+!
+!*      0.1   Declarations of arguments and result
+!             ------------------------------------
+!
+REAL, DIMENSION(:,:,:), INTENT(IN) :: PA, PB     ! input vectors
+!
+CHARACTER (LEN=4), DIMENSION(2), INTENT(IN) :: HLBCX    ! x-direction LBC type 
+CHARACTER (LEN=4), DIMENSION(2), INTENT(IN) :: HLBCY    ! y-direction LBC type 
+!
+REAL :: PDOTPROD                                     ! dot product
+!
+!*       0.2   Declarations of local variables
+!              -------------------------------
+!
+INTEGER :: JK,JI,JJ                         ! loop indexes
+!
+INTEGER :: IIB          ! indice I for the first inner mass point along x
+INTEGER :: IIE          ! indice I for the last inner mass point along x
+INTEGER :: IJB          ! indice J for the first inner mass point along y
+INTEGER :: IJE          ! indice J for the last inner mass point along y
+INTEGER :: IKB          ! indice K for the first inner mass point along z
+INTEGER :: IKE          ! indice K for the last inner mass point along z
+!
+INTEGER :: ILBXB,ILBYB,ILBXE,ILBYE          ! loop indices depending on the
+                                            ! lateral boundary conditions
+!
+INTEGER  :: IINFO_ll
+!JUAN16
+REAL, ALLOCATABLE, DIMENSION(:,:)     :: ZDOTPROD
+!JUAN16
+!
+!-------------------------------------------------------------------------------
+!
+!*       1.    COMPUTE LOOP BOUNDS
+!              -------------------
+!
+CALL GET_INDICE_ll(IIB,IJB,IIE,IJE)
+!
+IKB=1+JPVEXT
+IKE=SIZE(PA,3) - JPVEXT
+!
+IF(HLBCX(1)/='CYCL' .AND. LWEST_ll()) THEN
+  ILBXB = IIB-1    ! non cyclic condition at the physical boundary
+ELSE
+  ILBXB = IIB
+ENDIF
+!
+IF(HLBCX(2)/='CYCL' .AND. LEAST_ll()) THEN
+  ILBXE = IIE+1    ! non cyclic condition at the physical boundary
+ELSE
+  ILBXE = IIE
+ENDIF
+!
+ILBYB = IJB
+ILBYE = IJE
+!
+IF (.NOT.L2D) THEN        ! 3d version
+  IF(HLBCY(1)/='CYCL' .AND. LSOUTH_ll()) THEN
+    ILBYB = IJB-1    ! non cyclic condition at the physical boundary
+  ELSE
+    ILBYB = IJB
+  ENDIF
+!
+  IF(HLBCY(2)/='CYCL' .AND. LNORTH_ll()) THEN
+    ILBYE = IJE+1    ! non cyclic condition at the physical boundary
+  ELSE
+    ILBYE = IJE
+  ENDIF
+ELSE                      ! 2d version
+  ILBYB = IJB
+  ILBYE = IJB
+ENDIF
+!
+!*       2.    COMPUTE THE DOT PRODUCT 
+!              -----------------------
+!
+!JUAN16
+ALLOCATE(ZDOTPROD(ILBXB:ILBXE,ILBYB:ILBYE))
+ZDOTPROD    = 0.
+DO JK = IKB-1,IKE+1
+   DO JJ = ILBYB,ILBYE
+      DO JI = ILBXB,ILBXE
+         ZDOTPROD(JI,JJ) = ZDOTPROD(JI,JJ) + PA(JI,JJ,JK) * PB(JI,JJ,JK)
+      END DO
+   END DO
+END DO
+PDOTPROD = SUM_DD_R2_ll(ZDOTPROD)
+!JUAN16
+!
+!-------------------------------------------------------------------------------
+!
+END FUNCTION DOTPROD