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Diffstat (limited to 'tests/examplefiles/rust_example.rs')
| -rw-r--r-- | tests/examplefiles/rust_example.rs | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/tests/examplefiles/rust_example.rs b/tests/examplefiles/rust_example.rs new file mode 100644 index 00000000..1c0a70c3 --- /dev/null +++ b/tests/examplefiles/rust_example.rs @@ -0,0 +1,233 @@ +// Copyright 2012 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or +// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +// based on: +// http://shootout.alioth.debian.org/u32/benchmark.php?test=nbody&lang=java + +extern mod std; + +use core::os; + +// Using sqrt from the standard library is way slower than using libc +// directly even though std just calls libc, I guess it must be +// because the the indirection through another dynamic linker +// stub. Kind of shocking. Might be able to make it faster still with +// an llvm intrinsic. +#[nolink] +extern mod libc { + #[legacy_exports]; + fn sqrt(n: float) -> float; +} + +fn main() { + let args = os::args(); + let args = if os::getenv(~"RUST_BENCH").is_some() { + ~[~"", ~"4000000"] + } else if args.len() <= 1u { + ~[~"", ~"100000"] + } else { + args + }; + let n = int::from_str(args[1]).get(); + let mut bodies: ~[Body::props] = NBodySystem::make(); + io::println(fmt!("%f", NBodySystem::energy(bodies))); + let mut i = 0; + while i < n { + NBodySystem::advance(bodies, 0.01); + i += 1; + } + io::println(fmt!("%f", NBodySystem::energy(bodies))); +} + +mod NBodySystem { + use Body; + + pub fn make() -> ~[Body::props] { + let mut bodies: ~[Body::props] = + ~[Body::sun(), + Body::jupiter(), + Body::saturn(), + Body::uranus(), + Body::neptune()]; + + let mut px = 0.0; + let mut py = 0.0; + let mut pz = 0.0; + + let mut 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 + Body::offset_momentum(&mut bodies[0], px, py, pz); + + return bodies; + } + + pub fn advance(bodies: &mut [Body::props], dt: float) { + let mut i = 0; + while i < 5 { + let mut j = i + 1; + while j < 5 { + advance_one(&mut bodies[i], + &mut bodies[j], dt); + j += 1; + } + + i += 1; + } + + i = 0; + while i < 5 { + move_(&mut bodies[i], dt); + i += 1; + } + } + + pub fn advance_one(bi: &mut Body::props, + bj: &mut Body::props, + dt: float) unsafe { + let dx = bi.x - bj.x; + let dy = bi.y - bj.y; + let dz = bi.z - bj.z; + + let dSquared = dx * dx + dy * dy + dz * dz; + + let distance = ::libc::sqrt(dSquared); + let mag = dt / (dSquared * distance); + + bi.vx -= dx * bj.mass * mag; + bi.vy -= dy * bj.mass * mag; + bi.vz -= dz * bj.mass * mag; + + bj.vx += dx * bi.mass * mag; + bj.vy += dy * bi.mass * mag; + bj.vz += dz * bi.mass * mag; + } + + pub fn move_(b: &mut Body::props, dt: float) { + b.x += dt * b.vx; + b.y += dt * b.vy; + b.z += dt * b.vz; + } + + pub fn energy(bodies: &[Body::props]) -> float unsafe { + let mut dx; + let mut dy; + let mut dz; + let mut distance; + let mut e = 0.0; + + let mut 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 mut 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; + + distance = ::libc::sqrt(dx * dx + dy * dy + dz * dz); + e -= bodies[i].mass * bodies[j].mass / distance; + + j += 1; + } + + i += 1; + } + return e; + + } +} + +mod Body { + use Body; + + pub const PI: float = 3.141592653589793; + pub const SOLAR_MASS: float = 39.478417604357432; + // was 4 * PI * PI originally + pub const DAYS_PER_YEAR: float = 365.24; + + pub type props = + {mut x: float, + mut y: float, + mut z: float, + mut vx: float, + mut vy: float, + mut vz: float, + mass: float}; + + pub fn jupiter() -> Body::props { + return {mut x: 4.84143144246472090e+00, + mut y: -1.16032004402742839e+00, + mut z: -1.03622044471123109e-01, + mut vx: 1.66007664274403694e-03 * DAYS_PER_YEAR, + mut vy: 7.69901118419740425e-03 * DAYS_PER_YEAR, + mut vz: -6.90460016972063023e-05 * DAYS_PER_YEAR, + mass: 9.54791938424326609e-04 * SOLAR_MASS}; + } + + pub fn saturn() -> Body::props { + return {mut x: 8.34336671824457987e+00, + mut y: 4.12479856412430479e+00, + mut z: -4.03523417114321381e-01, + mut vx: -2.76742510726862411e-03 * DAYS_PER_YEAR, + mut vy: 4.99852801234917238e-03 * DAYS_PER_YEAR, + mut vz: 2.30417297573763929e-05 * DAYS_PER_YEAR, + mass: 2.85885980666130812e-04 * SOLAR_MASS}; + } + + pub fn uranus() -> Body::props { + return {mut x: 1.28943695621391310e+01, + mut y: -1.51111514016986312e+01, + mut z: -2.23307578892655734e-01, + mut vx: 2.96460137564761618e-03 * DAYS_PER_YEAR, + mut vy: 2.37847173959480950e-03 * DAYS_PER_YEAR, + mut vz: -2.96589568540237556e-05 * DAYS_PER_YEAR, + mass: 4.36624404335156298e-05 * SOLAR_MASS}; + } + + pub fn neptune() -> Body::props { + return {mut x: 1.53796971148509165e+01, + mut y: -2.59193146099879641e+01, + mut z: 1.79258772950371181e-01, + mut vx: 2.68067772490389322e-03 * DAYS_PER_YEAR, + mut vy: 1.62824170038242295e-03 * DAYS_PER_YEAR, + mut vz: -9.51592254519715870e-05 * DAYS_PER_YEAR, + mass: 5.15138902046611451e-05 * SOLAR_MASS}; + } + + pub fn sun() -> Body::props { + return {mut x: 0.0, + mut y: 0.0, + mut z: 0.0, + mut vx: 0.0, + mut vy: 0.0, + mut vz: 0.0, + mass: SOLAR_MASS}; + } + + pub fn offset_momentum(props: &mut Body::props, + px: float, py: float, pz: float) { + props.vx = -px / SOLAR_MASS; + props.vy = -py / SOLAR_MASS; + props.vz = -pz / SOLAR_MASS; + } + +} |