From e07ae62012ec2ccb3d283670a90252ea6d4bf6cd Mon Sep 17 00:00:00 2001
From: goodale <goodale@daab82bb-f315-4ad1-b6d0-9353ff8b6e27>
Date: Tue, 28 Mar 2000 07:04:08 +0000
Subject: 60% more MFlop/s

Tom


git-svn-id: http://svn.cactuscode.org/arrangements/CactusWave/WaveToyFreeF90/trunk@15 daab82bb-f315-4ad1-b6d0-9353ff8b6e27
---
 src/WaveToy.F90 | 24 ++++++++++++++++++------
 1 file changed, 18 insertions(+), 6 deletions(-)

diff --git a/src/WaveToy.F90 b/src/WaveToy.F90
index eaa279c..1a02912 100644
--- a/src/WaveToy.F90
+++ b/src/WaveToy.F90
@@ -42,7 +42,10 @@ subroutine WaveToyFreeF90_Evolution(CCTK_ARGUMENTS)
   !  Declare local variables
   INTEGER   :: i,j,k
   INTEGER   :: istart, jstart, kstart, iend, jend, kend
+
   CCTK_REAL :: dx,dy,dz,dt
+  CCTK_REAL :: dx2,dy2,dz2,dt2
+  CCTK_REAL :: dx2i,dy2i,dz2i
   
   ! Set up shorthands
   ! -----------------
@@ -51,6 +54,15 @@ subroutine WaveToyFreeF90_Evolution(CCTK_ARGUMENTS)
   dz = CCTK_DELTA_SPACE(3)
   dt = CCTK_DELTA_TIME
   
+  dx2 = dx*dx
+  dy2 = dy*dy
+  dz2 = dz*dz
+  dt2 = dt*dt
+
+  dx2i = 1.0/dx2
+  dy2i = 1.0/dy2
+  dz2i = 1.0/dz2
+
   istart = 2
   jstart = 2
   kstart = 2
@@ -66,12 +78,12 @@ subroutine WaveToyFreeF90_Evolution(CCTK_ARGUMENTS)
         do i = istart, iend
            
            phi_tmp(i,j,k) =                         &
-                2.0*(1.0 - (dt**2)*(1.0/dx**2 +     &
-                1.0/dy**2 +1.0/dz**2))*phi(i,j,k) - &
-                phi_old(i,j,k) + (dt**2) *          &
-                ((phi(i+1,j,k)+phi(i-1,j,k))/dx**2  &
-                +(phi(i,j+1,k)+phi(i,j-1,k))/dy**2  &
-                +(phi(i,j,k+1)+phi(i,j,k-1))/dz**2)
+                2.0*(1.0 - (dt2)*(dx2i +            &
+                dy2i + dz2i))*phi(i,j,k) -          &
+                phi_old(i,j,k) + (dt2) *            &
+                ((phi(i+1,j,k)+phi(i-1,j,k))*dx2i   &
+                +(phi(i,j+1,k)+phi(i,j-1,k))*dy2i   &
+                +(phi(i,j,k+1)+phi(i,j,k-1))*dz2i)
            
         end do
      end do
-- 
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