From d693603c8997f59f33da0ae30fa241f377924c46 Mon Sep 17 00:00:00 2001 From: Lindsey Kuper Date: Fri, 25 Mar 2011 13:40:40 -0700 Subject: [PATCH 1/2] Updates to the nbody demo. --- src/test/bench/shootout/nbody.rs | 85 ++++++++++++++++++-------------- 1 file changed, 47 insertions(+), 38 deletions(-) diff --git a/src/test/bench/shootout/nbody.rs b/src/test/bench/shootout/nbody.rs index b0ac2d446976..3c6c83a033a4 100644 --- a/src/test/bench/shootout/nbody.rs +++ b/src/test/bench/shootout/nbody.rs @@ -3,6 +3,8 @@ fn main() { + log "foo"; + let vec[int] inputs = vec( 50000 //these segfault :( @@ -55,7 +57,9 @@ mod NBodySystem { py += body.vy * body.mass; pz += body.vz * body.mass; } - bodies.(0) = Body.offsetMomentum(bodies.(0), px, py, pz); + + // side-effecting + Body.offsetMomentum(bodies.(0), px, py, pz); ret bodies; } @@ -75,6 +79,14 @@ mod NBodySystem { let float distance; rustrt.squareroot(dSquared, distance); let float mag = dt / (dSquared * distance); + + iBody.vx -= dx * jbody.mass * mag; + iBody.vy -= dy * jbody.mass * mag; + iBody.vz -= dz * jbody.mass * mag; + + jbody.vx += dx * iBody.mass * mag; + jbody.vy += dy * iBody.mass * mag; + jbody.vz += dz * iBody.mass * mag; } } @@ -124,8 +136,8 @@ mod NBodySystem { mod Body { - const float PI = 3.141592; - const float SOLAR_MASS = 39.478417; // was 4 * PI * PI originally + const float PI = 3.14; + const float SOLAR_MASS = 39.47; // was 4 * PI * PI originally const float DAYS_PER_YEAR = 365.24; type props = rec(float x, @@ -141,49 +153,49 @@ mod Body { // fit into a 32-bit int. let Body.props p; - p.x = 4.841431e+00; - p.y = -1.160320e+00; - p.z = -1.036220e-01; - p.vx = 1.660076e-03 * DAYS_PER_YEAR; - p.vy = 7.699011e-03 * DAYS_PER_YEAR; - p.vz = -6.904600e-05 * DAYS_PER_YEAR; - p.mass = 9.547919e-04 * SOLAR_MASS; + p.x = 4.84e+00; + p.y = -1.16e+00; + p.z = -1.03e-01; + p.vx = 1.66e-03 * DAYS_PER_YEAR; + p.vy = 7.69e-03 * DAYS_PER_YEAR; + p.vz = -6.90e-05 * DAYS_PER_YEAR; + p.mass = 9.54e-04 * SOLAR_MASS; ret p; } fn saturn() -> Body.props { let Body.props p; - p.x = 8.343366e+00; - p.y = 4.124798e+00; - p.z = -4.035234e-01; - p.vx = -2.767425e-03 * DAYS_PER_YEAR; - p.vy = 4.998528e-03 * DAYS_PER_YEAR; - p.vz = 2.304172e-05 * DAYS_PER_YEAR; - p.mass = 2.858859e-04 * SOLAR_MASS; + p.x = 8.34e+00; + p.y = 4.12e+00; + p.z = -4.03e-01; + p.vx = -2.76e-03 * DAYS_PER_YEAR; + p.vy = 4.99e-03 * DAYS_PER_YEAR; + p.vz = 2.30e-05 * DAYS_PER_YEAR; + p.mass = 2.85e-04 * SOLAR_MASS; ret p; } fn uranus() -> Body.props { let Body.props p; - p.x = 1.289436e+01; - p.y = -1.511115e+01; - p.z = -2.233075e-01; - p.vx = 2.964601e-03 * DAYS_PER_YEAR; - p.vy = 2.378471e-03 * DAYS_PER_YEAR; - p.vz = -2.965895e-05 * DAYS_PER_YEAR; - p.mass = 4.366244e-05 * SOLAR_MASS; + p.x = 1.28e+01; + p.y = -1.51e+01; + p.z = -2.23e-01; + p.vx = 2.96e-03 * DAYS_PER_YEAR; + p.vy = 2.37e-03 * DAYS_PER_YEAR; + p.vz = -2.96e-05 * DAYS_PER_YEAR; + p.mass = 4.36e-05 * SOLAR_MASS; ret p; } fn neptune() -> Body.props { let Body.props p; - p.x = 1.537969e+01; - p.y = -2.591931e+01; - p.z = 1.792587e-01; - p.vx = 2.680677e-03 * DAYS_PER_YEAR; - p.vy = 1.628241e-03 * DAYS_PER_YEAR; - p.vz = -9.515922e-05 * DAYS_PER_YEAR; - p.mass = 5.151389e-05 * SOLAR_MASS; + p.x = 1.53e+01; + p.y = -2.59e+01; + p.z = 1.79e-01; + p.vx = 2.68e-03 * DAYS_PER_YEAR; + p.vy = 1.62e-03 * DAYS_PER_YEAR; + p.vz = -9.51e-05 * DAYS_PER_YEAR; + p.mass = 5.15e-05 * SOLAR_MASS; ret p; } @@ -193,17 +205,14 @@ mod Body { ret p; } - fn offsetMomentum(Body.props props, + impure fn offsetMomentum(mutable Body.props props, float px, float py, float pz) -> Body.props { - // TODO: should we create a new one or mutate the original? - let Body.props p = props; - p.vx = -px / SOLAR_MASS; - p.vy = -py / SOLAR_MASS; - p.vz = -pz / SOLAR_MASS; - ret p; + props.vx = -px / SOLAR_MASS; + props.vy = -py / SOLAR_MASS; + props.vz = -pz / SOLAR_MASS; } } From ad1e44a9f2aaf352a01b3aea00b8a7989ecffcb0 Mon Sep 17 00:00:00 2001 From: Lindsey Kuper Date: Sat, 26 Mar 2011 15:14:22 -0700 Subject: [PATCH 2/2] Got the nbody demo working, and hopefully faster, too! --- src/test/bench/shootout/nbody.rs | 218 ++++++++++++++++--------------- 1 file changed, 112 insertions(+), 106 deletions(-) diff --git a/src/test/bench/shootout/nbody.rs b/src/test/bench/shootout/nbody.rs index bfa77674cabf..9df439f2fc65 100644 --- a/src/test/bench/shootout/nbody.rs +++ b/src/test/bench/shootout/nbody.rs @@ -4,8 +4,6 @@ fn main() { - log "foo"; - let vec[int] inputs = vec( 50000 //these segfault :( @@ -17,13 +15,12 @@ fn main() { let vec[Body.props] bodies = NBodySystem.MakeNBodySystem(); for (int n in inputs) { - // TODO: make #fmt handle floats? log NBodySystem.energy(bodies); let int i = 0; while (i < n) { - bodies = NBodySystem.advance(bodies, 0.01); - i = i+1; + NBodySystem.advance(bodies, 0.01); + i += 1; } log NBodySystem.energy(bodies); } @@ -40,7 +37,6 @@ native "rust" mod rustrt { mod NBodySystem { fn MakeNBodySystem() -> vec[Body.props] { - // can't iterate over a record? how about a vector, then? let vec[Body.props] bodies = vec( // these each return a Body.props Body.sun(), @@ -53,10 +49,13 @@ mod NBodySystem { let float py = 0.0; let float pz = 0.0; - for (Body.props body in bodies) { - px += body.vx * body.mass; - py += body.vy * body.mass; - pz += body.vz * body.mass; + let int i = 0; + while (i < 5) { + px += bodies.(i).vx * bodies.(i).mass; + py += bodies.(i).vy * bodies.(i).mass; + pz += bodies.(i).vz * bodies.(i).mass; + + i += 1; } // side-effecting @@ -65,15 +64,15 @@ mod NBodySystem { ret bodies; } - fn advance(vec[Body.props] bodies, float dt) -> vec[Body.props] { - for (Body.props ibody in bodies) { + fn advance(vec[Body.props] bodies, float dt) -> () { - let Body.props iBody = ibody; - - for (Body.props jbody in bodies) { - let float dx = iBody.x - jbody.x; - let float dy = iBody.y - jbody.y; - let float dz = iBody.z - jbody.z; + let int i = 0; + while (i < 5) { + let int j = i+1; + while (j < 5) { + let float dx = bodies.(i).x - bodies.(j).x; + let float dy = bodies.(i).y - bodies.(j).y; + let float dz = bodies.(i).z - bodies.(j).z; let float dSquared = dx * dx + dy * dy + dz * dz; @@ -81,23 +80,30 @@ mod NBodySystem { rustrt.squareroot(dSquared, distance); let float mag = dt / (dSquared * distance); - iBody.vx -= dx * jbody.mass * mag; - iBody.vy -= dy * jbody.mass * mag; - iBody.vz -= dz * jbody.mass * mag; + bodies.(i).vx -= dx * bodies.(j).mass * mag; + bodies.(i).vy -= dy * bodies.(j).mass * mag; + bodies.(i).vz -= dz * bodies.(j).mass * mag; + + bodies.(j).vx += dx * bodies.(i).mass * mag; + bodies.(j).vy += dy * bodies.(i).mass * mag; + bodies.(j).vz += dz * bodies.(i).mass * mag; + + j += 1; - jbody.vx += dx * iBody.mass * mag; - jbody.vy += dy * iBody.mass * mag; - jbody.vz += dz * iBody.mass * mag; } - } - for (Body.props body in bodies) { - body.x += dt * body.vx; - body.y += dt * body.vy; - body.z += dt * body.vz; + i += 1; } - ret bodies; + i = 0; + while (i < 5) { + + bodies.(i).x += dt * bodies.(i).vx; + bodies.(i).y += dt * bodies.(i).vy; + bodies.(i).z += dt * bodies.(i).vz; + + i += 1; + } } fn energy(vec[Body.props] bodies) -> float { @@ -107,110 +113,110 @@ mod NBodySystem { let float distance; let float e = 0.0; - for (Body.props ibody in bodies) { - - // do we need this? - let Body.props iBody = ibody; - - e += 0.5 * iBody.mass * - ( iBody.vx * iBody.vx - + iBody.vy * iBody.vy - + iBody.vz * iBody.vz ); - - for (Body.props jbody in bodies) { - - // do we need this? - let Body.props jBody = jbody; - - dx = iBody.x - jBody.x; - dy = iBody.y - jBody.y; - dz = iBody.z - jBody.z; + let int i = 0; + while (i < 5) { + e += 0.5 * bodies.(i).mass * + ( bodies.(i).vx * bodies.(i).vx + + bodies.(i).vy * bodies.(i).vy + + bodies.(i).vz * bodies.(i).vz ); + + let int j = i+1; + while (j < 5) { + dx = bodies.(i).x - bodies.(j).x; + dy = bodies.(i).y - bodies.(j).y; + dz = bodies.(i).z - bodies.(j).z; rustrt.squareroot(dx*dx + dy*dy + dz*dz, distance); - e -= (iBody.mass * jBody.mass) / distance; + e -= (bodies.(i).mass * bodies.(j).mass) / distance; + + j += 1; } + + i += 1; } ret e; - } + } } mod Body { - - const float PI = 3.14; - const float SOLAR_MASS = 39.47; // was 4 * PI * PI originally + + const float PI = 3.141592653589793; + const float SOLAR_MASS = 39.478417604357432; // was 4 * PI * PI originally const float DAYS_PER_YEAR = 365.24; - type props = rec(float x, - float y, - float z, - float vx, - float vy, - float vz, + type props = rec(mutable float x, + mutable float y, + mutable float z, + mutable float vx, + mutable float vy, + mutable float vz, float mass); fn jupiter() -> Body.props { - // current limitation of the float lexer: decimal part has to - // fit into a 32-bit int. - - let Body.props p; - p.x = 4.84e+00; - p.y = -1.16e+00; - p.z = -1.03e-01; - p.vx = 1.66e-03 * DAYS_PER_YEAR; - p.vy = 7.69e-03 * DAYS_PER_YEAR; - p.vz = -6.90e-05 * DAYS_PER_YEAR; - p.mass = 9.54e-04 * SOLAR_MASS; - ret p; + ret rec( + mutable x = 4.84143144246472090e+00, + mutable y = -1.16032004402742839e+00, + mutable z = -1.03622044471123109e-01, + mutable vx = 1.66007664274403694e-03 * DAYS_PER_YEAR, + mutable vy = 7.69901118419740425e-03 * DAYS_PER_YEAR, + mutable vz = -6.90460016972063023e-05 * DAYS_PER_YEAR, + mass = 9.54791938424326609e-04 * SOLAR_MASS + ); } fn saturn() -> Body.props { - let Body.props p; - p.x = 8.34e+00; - p.y = 4.12e+00; - p.z = -4.03e-01; - p.vx = -2.76e-03 * DAYS_PER_YEAR; - p.vy = 4.99e-03 * DAYS_PER_YEAR; - p.vz = 2.30e-05 * DAYS_PER_YEAR; - p.mass = 2.85e-04 * SOLAR_MASS; - ret p; + ret rec( + mutable x = 8.34336671824457987e+00, + mutable y = 4.12479856412430479e+00, + mutable z = -4.03523417114321381e-01, + mutable vx = -2.76742510726862411e-03 * DAYS_PER_YEAR, + mutable vy = 4.99852801234917238e-03 * DAYS_PER_YEAR, + mutable vz = 2.30417297573763929e-05 * DAYS_PER_YEAR, + mass = 2.85885980666130812e-04 * SOLAR_MASS + ); } fn uranus() -> Body.props { - let Body.props p; - p.x = 1.28e+01; - p.y = -1.51e+01; - p.z = -2.23e-01; - p.vx = 2.96e-03 * DAYS_PER_YEAR; - p.vy = 2.37e-03 * DAYS_PER_YEAR; - p.vz = -2.96e-05 * DAYS_PER_YEAR; - p.mass = 4.36e-05 * SOLAR_MASS; - ret p; + ret rec( + mutable x = 1.28943695621391310e+01, + mutable y = -1.51111514016986312e+01, + mutable z = -2.23307578892655734e-01, + mutable vx = 2.96460137564761618e-03 * DAYS_PER_YEAR, + mutable vy = 2.37847173959480950e-03 * DAYS_PER_YEAR, + mutable vz = -2.96589568540237556e-05 * DAYS_PER_YEAR, + mass = 4.36624404335156298e-05 * SOLAR_MASS + ); } fn neptune() -> Body.props { - let Body.props p; - p.x = 1.53e+01; - p.y = -2.59e+01; - p.z = 1.79e-01; - p.vx = 2.68e-03 * DAYS_PER_YEAR; - p.vy = 1.62e-03 * DAYS_PER_YEAR; - p.vz = -9.51e-05 * DAYS_PER_YEAR; - p.mass = 5.15e-05 * SOLAR_MASS; - ret p; + ret rec( + mutable x = 1.53796971148509165e+01, + mutable y = -2.59193146099879641e+01, + mutable z = 1.79258772950371181e-01, + mutable vx = 2.68067772490389322e-03 * DAYS_PER_YEAR, + mutable vy = 1.62824170038242295e-03 * DAYS_PER_YEAR, + mutable vz = -9.51592254519715870e-05 * DAYS_PER_YEAR, + mass = 5.15138902046611451e-05 * SOLAR_MASS + ); } fn sun() -> Body.props { - let Body.props p; - p.mass = SOLAR_MASS; - ret p; + ret rec( + mutable x = 0.0, + mutable y = 0.0, + mutable z = 0.0, + mutable vx = 0.0, + mutable vy = 0.0, + mutable vz = 0.0, + mass = SOLAR_MASS + ); } - impure fn offsetMomentum(mutable Body.props props, - float px, - float py, - float pz) -> Body.props { - + impure fn offsetMomentum(&Body.props props, + float px, + float py, + float pz) -> () { props.vx = -px / SOLAR_MASS; props.vy = -py / SOLAR_MASS; props.vz = -pz / SOLAR_MASS;