Juan 14/09/2020 : tridiag_wind.f90 , OpenACC optimisation -> DO CONCURRENT + ...

Juan 14/09/2020 : tridiag_wind.f90 , OpenACC optimisation -> DO CONCURRENT +  loop gang vector collapse

src/MNH/tridiag_wind.f90

@@ -269,22 +269,21 @@ IF ( PIMPL > 1.E-10 ) THEN
       PVARP(JI,JJ,IKB) = ZY(JI,JJ,IKB) / ZBET(JI,JJ)
   END DO !CONCURRENT
   !
-  DO JK = IKB+KKL,IKE-KKL,KKL 
-!$acc loop collapse(2) independent
-    DO JJ=1,JJU
-      DO JI=1,JIU
+  !$acc loop  seq
+  DO JK = IKB+KKL,IKE-KKL,KKL
+     !$acc loop gang, vector collapse(2)
+     DO  CONCURRENT ( JJ=1:JJU , JI=1:JIU )  
         ZGAM(JI,JJ,JK) = PIMPL * PA(JI,JJ,JK) / PRHODJA(JI,JJ,JK-KKL) / ZBET(JI,JJ)  
-                                                    ! gam(k) = c(k-1) / bet
+        ! gam(k) = c(k-1) / bet
         ZBET(JI,JJ)    = 1. - PIMPL * (  PA(JI,JJ,JK) * (1. + ZGAM(JI,JJ,JK))  &
-                                 + PA(JI,JJ,JK+KKL)                      &
-                                ) / PRHODJA(JI,JJ,JK)  
-                                                    ! bet = b(k) - a(k)* gam(k)  
+             + PA(JI,JJ,JK+KKL)                      &
+             ) / PRHODJA(JI,JJ,JK)  
+        ! bet = b(k) - a(k)* gam(k)  
         PVARP(JI,JJ,JK)= ( ZY(JI,JJ,JK) - PIMPL * PA(JI,JJ,JK) / PRHODJA(JI,JJ,JK) &
-                    * PVARP(JI,JJ,JK-KKL)                                  &
-                   ) / ZBET(JI,JJ)
-                                        ! res(k) = (y(k) -a(k)*res(k-1))/ bet 
-      END DO
-    END DO
+             * PVARP(JI,JJ,JK-KKL)                                  &
+             ) / ZBET(JI,JJ)
+        ! res(k) = (y(k) -a(k)*res(k-1))/ bet 
+     END DO ! CONCURRENT
   END DO
   ! special treatment for the last level
   DO CONCURRENT ( JI=1:JIU,JJ=1:JJU)