b8198005db
* OPT: Little optimization in nbody benchmark. [GB.JIT] * BUG: Fix translation of loops. * BUG: Fix label generation.
210 lines
4.2 KiB
Text
Executable file
210 lines
4.2 KiB
Text
Executable file
#!/usr/bin/env gbs3
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Class Body
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Static Private SOLAR_MASS As Float = 4 * Pi * Pi
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Private Const DAYS_PER_YEAR As Float = 365.24
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Public X As Float
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Public Y As Float
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Public Z As Float
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Public VX As Float
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Public VY As Float
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Public VZ As Float
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Public Mass As Float
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Static Public Sub Jupiter() As Body
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Dim P As New Body
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p.x = 4.84143144246472090e+00
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p.y = -1.16032004402742839e+00
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p.z = -1.03622044471123109e-01
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p.vx = 1.66007664274403694e-03 * DAYS_PER_YEAR
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p.vy = 7.69901118419740425e-03 * DAYS_PER_YEAR
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p.vz = -6.90460016972063023e-05 * DAYS_PER_YEAR
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p.mass = 9.54791938424326609e-04 * SOLAR_MASS
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return p
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End
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Static Public Sub Saturn() As Body
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Dim P As New Body
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p.x = 8.34336671824457987e+00
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p.y = 4.12479856412430479e+00
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p.z = -4.03523417114321381e-01
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p.vx = -2.76742510726862411e-03 * DAYS_PER_YEAR
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p.vy = 4.99852801234917238e-03 * DAYS_PER_YEAR
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p.vz = 2.30417297573763929e-05 * DAYS_PER_YEAR
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p.mass = 2.85885980666130812e-04 * SOLAR_MASS
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return p
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End
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Static Public Sub Uranus() As Body
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Dim P As New Body
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p.x = 1.28943695621391310e+01
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p.y = -1.51111514016986312e+01
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p.z = -2.23307578892655734e-01
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p.vx = 2.96460137564761618e-03 * DAYS_PER_YEAR
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p.vy = 2.37847173959480950e-03 * DAYS_PER_YEAR
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p.vz = -2.96589568540237556e-05 * DAYS_PER_YEAR
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p.mass = 4.36624404335156298e-05 * SOLAR_MASS
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return p
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End
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Static Public Sub Neptune() As Body
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Dim P As New Body
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p.x = 1.53796971148509165e+01
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p.y = -2.59193146099879641e+01
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p.z = 1.79258772950371181e-01
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p.vx = 2.68067772490389322e-03 * DAYS_PER_YEAR
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p.vy = 1.62824170038242295e-03 * DAYS_PER_YEAR
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p.vz = -9.51592254519715870e-05 * DAYS_PER_YEAR
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p.mass = 5.15138902046611451e-05 * SOLAR_MASS
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return p
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End
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Static Public Sub Sun() As Body
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Dim P As New Body
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p.mass = SOLAR_MASS
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return p
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End
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Public Sub OffsetMomentum(px As Float, py As Float, pz As Float) As Body
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vx = -px / SOLAR_MASS
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vy = -py / SOLAR_MASS
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vz = -pz / SOLAR_MASS
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Return Me
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End
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End Class
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Class NBodySystem
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Private Bodies As Body[]
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Public Sub _new()
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Dim PX, PY, PZ As Float
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Dim I As Integer
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Bodies = [ Body.Sun(), Body.Jupiter(), Body.Saturn(), Body.Uranus(), Body.Neptune() ]
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For I = 0 To Bodies.Max
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PX += Bodies[I].vx * Bodies[I].mass
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PY += Bodies[I].vy * Bodies[I].mass
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PZ += Bodies[I].vz * Bodies[I].mass
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Next
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Bodies[0].offsetMomentum(PX, PY, PZ)
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End
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Public Sub Advance(dt As Float)
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Dim I, J As Integer
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Dim iBody, jBody As Body
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Dim dx, dy, dz As Float
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Dim ix, iy, iz As Float
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Dim dSquared, fMag As Float
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Dim iMass, jMass, iMag, jMag As Float
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For I = 0 To Bodies.Max
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iBody = Bodies[I]
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iMass = iBody.mass
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ix = iBody.x
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iy = iBody.y
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iz = iBody.z
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For J = I + 1 To Bodies.Max
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jBody = Bodies[J]
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jMass = jBody.mass
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dx = ix - jBody.x
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dy = iy - jBody.y
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dz = iz - jBody.z
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dSquared = dx * dx + dy * dy + dz * dz
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fMag = dt / (dSquared * Sqr(dSquared))
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iMag = iMass * fMag
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jMag = jMass * fMag
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iBody.vx -= dx * jMag
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iBody.vy -= dy * jMag
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iBody.vz -= dz * jMag
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jBody.vx += dx * iMag
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jBody.vy += dy * iMag
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jBody.vz += dz * iMag
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Next
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Next
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For I = 0 To Bodies.Max
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iBody = Bodies[i]
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iBody.x += dt * iBody.vx
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iBody.y += dt * iBody.vy
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iBody.z += dt * iBody.vz
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Next
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End
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Public Sub Energy() As Float
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Dim dx, dy, dz, distance, E As Float
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Dim iBody, jBody As Body
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Dim I, J As Integer
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For I = 0 To Bodies.Max
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iBody = bodies[i]
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E += 0.5 * iBody.mass * (iBody.vx * iBody.vx + iBody.vy * iBody.vy + iBody.vz * iBody.vz)
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For J = I + 1 To Bodies.Max
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jBody = Bodies[J]
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dx = iBody.x - jBody.x
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dy = iBody.y - jBody.y
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dz = iBody.z - jBody.z
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distance = Sqr(dx*dx + dy*dy + dz*dz)
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E -= (iBody.mass * jBody.mass) / distance
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Next
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Next
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return E
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End
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End Class
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Dim S As New NBodySystem
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Dim I, N As Integer
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For N = 1 To 5
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Print S.Energy()
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For I = 1 To 100000
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S.Advance(0.01)
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Next
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Next
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Print S.Energy()
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