EVOLUTION: Parallelize evolve_ssp324() using OpenMP.

Signed-off-by: Grzegorz Kowal <grzegorz@amuncode.org>

sources/evolution.F90

@@ -2682,7 +2682,7 @@ module evolution
 !
   subroutine evolve_ssp324()
 
-    use blocks     , only : block_data, list_data
+    use blocks    , only : block_data, list_data, data_blocks, get_dblocks
     use boundaries, only : boundary_fluxes
     use equations , only : errors, ibp, cmax
     use helpers   , only : print_message
@@ -2693,7 +2693,7 @@ module evolution
     type(block_data), pointer :: pdata
 
     logical         :: test, cond
-    integer         :: nrej, i, status
+    integer         :: i, l, n, nrej, status
     real(kind=8)    :: tm, dtm, dh, fc
 
     real(kind=8), parameter :: onethird = 1.0d+00 / 3.0d+00,                   &
@@ -2706,6 +2706,7 @@ module evolution
     test = .true.
     cond = .true.
     nrej = 0
+    n    = get_dblocks()
 
 ! at the entry point we assume the previous solution of conserved variables U(n)
 ! is stored in pdata%u(:,:,:,:,1) and the primitive variables are already
@@ -2723,15 +2724,15 @@ module evolution
 
 != preparation step: U(1) = U(n)
 !
-      pdata => list_data
+!$omp parallel do default(shared) private(pdata)
-      do while (associated(pdata))
+      do l = 1, n
+        pdata => data_blocks(l)%ptr
 
         pdata%uu(:,:,:,:,2) = pdata%uu(:,:,:,:,1)
 
         pdata%u => pdata%uu(:,:,:,:,2)
-
-        pdata => pdata%next
       end do
+!$omp end parallel do
 
 != 1st to 3rd steps: U(1) = U(1) + ½ dt F[U(1)], for i = 1...3
 !
@@ -2740,24 +2741,24 @@ module evolution
         tm  = time + (i - 1) * dh
         dtm = dh
 
-        pdata => list_data
+!$omp parallel do default(shared) private(pdata)
-        do while (associated(pdata))
+        do l = 1, n
+          pdata => data_blocks(l)%ptr
 
           call update_increment(pdata)
           call update_sources(pdata, tm, dtm, pdata%du(:,:,:,:))
-
-          pdata => pdata%next
         end do
+!$omp end parallel do
 
         call boundary_fluxes()
 
-        pdata => list_data
+!$omp parallel do default(shared) private(pdata)
-        do while (associated(pdata))
+        do l = 1, n
+          pdata => data_blocks(l)%ptr
 
           pdata%uu(:,:,:,:,2) = pdata%uu(:,:,:,:,2) + dh * pdata%du(:,:,:,:)
-
-          pdata => pdata%next
         end do
+!$omp end parallel do
 
         call update_variables(tm, dtm, status)
         if (status /= 0) go to 100
@@ -2766,16 +2767,16 @@ module evolution
 
 != 4th step: U(1) = ⅔ U(n) + ⅓ U(1), U(2) = ⅓ U(n) + ⅔ U(1)
 !
-      pdata => list_data
+!$omp parallel do default(shared) private(pdata)
-      do while (associated(pdata))
+      do l = 1, n
+        pdata => data_blocks(l)%ptr
 
         pdata%uu(:,:,:,:,3) = onethird * pdata%uu(:,:,:,:,1)                   &
                             + twothird * pdata%uu(:,:,:,:,2)
         pdata%uu(:,:,:,:,2) = twothird * pdata%uu(:,:,:,:,1)                   &
                             + onethird * pdata%uu(:,:,:,:,2)
-
-        pdata => pdata%next
       end do
+!$omp end parallel do
 
       call update_variables(tm, dtm, status)
       if (status /= 0) go to 100
@@ -2785,54 +2786,54 @@ module evolution
       tm  = time + dh
       dtm = dh
 
-      pdata => list_data
+!$omp parallel do default(shared) private(pdata)
-      do while (associated(pdata))
+      do l = 1, n
+        pdata => data_blocks(l)%ptr
 
         call update_increment(pdata)
         call update_sources(pdata, tm, dtm, pdata%du(:,:,:,:))
-
-        pdata => pdata%next
       end do
+!$omp end parallel do
 
       call boundary_fluxes()
 
-      pdata => list_data
+!$omp parallel do default(shared) private(pdata)
-      do while (associated(pdata))
+      do l = 1, n
+        pdata => data_blocks(l)%ptr
 
         pdata%uu(:,:,:,:,2) = pdata%uu(:,:,:,:,2) + dh * pdata%du(:,:,:,:)
-
-        pdata => pdata%next
       end do
+!$omp end parallel do
 
       call update_variables(tm, dtm, status)
       if (status /= 0) go to 100
 
 != 6th step: U(2) = ½ (U(1) + U(2)) <- 2ⁿᵈ-order approximation
 !
-      pdata => list_data
+!$omp parallel do default(shared) private(pdata)
-      do while (associated(pdata))
+      do l = 1, n
+        pdata => data_blocks(l)%ptr
 
         pdata%uu(:,:,:,:,3) = 5.0d-01 * (pdata%uu(:,:,:,:,3) &
                                        + pdata%uu(:,:,:,:,2))
-
-        pdata => pdata%next
       end do
+!$omp end parallel do
 
 != 7th step: decay the magnetic divergence potential of both solutions
 !
       if (ibp > 0) then
         adecay(:) = exp(aglm(:) * cmax * dt)
 
-        pdata => list_data
+!$omp parallel do default(shared) private(pdata)
-        do while (associated(pdata))
+        do l = 1, n
+          pdata => data_blocks(l)%ptr
 
           pdata%uu(ibp,:,:,:,2) = adecay(pdata%meta%level)                     &
                                                        * pdata%uu(ibp,:,:,:,2)
           pdata%uu(ibp,:,:,:,3) = adecay(pdata%meta%level)                     &
                                                        * pdata%uu(ibp,:,:,:,3)
-
-          pdata => pdata%next
         end do
+!$omp end parallel do
       end if
 
 ! update the vector of errors
@@ -2869,13 +2870,13 @@ module evolution
 ! since the solution was rejected, we have to revert the primitive variables
 ! to the previous state
 !
-        pdata => list_data
+!$omp parallel do default(shared) private(pdata)
-        do while (associated(pdata))
+        do l = 1, n
+          pdata => data_blocks(l)%ptr
 
           pdata%u => pdata%uu(:,:,:,:,1)
-
-          pdata => pdata%next
         end do
+!$omp end parallel do
 
         call update_variables(tm, dtm, status)
         if (status /= 0) &
@@ -2889,15 +2890,15 @@ module evolution
 
 != final step: U(n+1) = U(1) - update the accepted solution
 !
-    pdata => list_data
+!$omp parallel do default(shared) private(pdata)
-    do while (associated(pdata))
+    do l = 1, n
+      pdata => data_blocks(l)%ptr
 
       pdata%uu(:,:,:,:,1) = pdata%uu(:,:,:,:,2)
 
       pdata%u => pdata%uu(:,:,:,:,1)
-
-      pdata => pdata%next
     end do
+!$omp end parallel do
 
 !-------------------------------------------------------------------------------
 !