From a457121df89fc3569421ccf68534a74838877c1f Mon Sep 17 00:00:00 2001
From: goodale <goodale@4451c3c6-1034-4891-99ea-21147727ccdf>
Date: Tue, 28 Mar 2000 07:04:06 +0000
Subject: 60% more MFlop/s

Tom


git-svn-id: http://svn.cactuscode.org/arrangements/CactusWave/WaveToyF77/trunk@49 4451c3c6-1034-4891-99ea-21147727ccdf
---
 src/WaveToy.F77 | 23 +++++++++++++++++------
 1 file changed, 17 insertions(+), 6 deletions(-)

diff --git a/src/WaveToy.F77 b/src/WaveToy.F77
index 13e1fad..6130447 100644
--- a/src/WaveToy.F77
+++ b/src/WaveToy.F77
@@ -42,6 +42,8 @@ c     Declare variables in argument list
       INTEGER   i,j,k,ierr
       INTEGER   istart, jstart, kstart, iend, jend, kend
       CCTK_REAL dx,dy,dz,dt
+      CCTK_REAL dx2,dy2,dz2,dt2
+      CCTK_REAL dx2i,dy2i,dz2i
 
 c     Set up shorthands
 c     -----------------
@@ -50,6 +52,15 @@ c     -----------------
       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
@@ -65,12 +76,12 @@ c     ----------------
             do i = istart, iend
                
                phi_next(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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