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bench: Update shootout-nbody for style

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This commit is contained in:
Brian Anderson 2012-01-14 20:26:44 -08:00
parent 93dcb9fb6b
commit 1588ae204e
1 changed files with 20 additions and 22 deletions
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42
src/test/bench/shootout-nbody.rs
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@ -1,31 +1,29 @@
// based on:
// http://shootout.alioth.debian.org/u32/benchmark.php?test=nbody&lang=java
#[abi = "cdecl"]
use std;
// 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]
native mod llvm {
native mod libc {
fn sqrt(n: float) -> float;
}
fn main() {
//
// Leave these commented out to
// finish in a reasonable time
// during 'make check' under valgrind
// 5000000
// 50000000
let inputs: [int] = [50000, 500000];
fn main(args: [str]) {
let n = if vec::len(args) == 2u {
int::from_str(args[1])
} else {
1000000
};
let bodies: [Body::props] = NBodySystem::MakeNBodySystem();
for n: int in inputs {
log(debug, NBodySystem::energy(bodies));
let i: int = 0;
while i < n { NBodySystem::advance(bodies, 0.01); i += 1; }
log(debug, NBodySystem::energy(bodies));
}
std::io::println(#fmt("%f", NBodySystem::energy(bodies)));
let i: int = 0;
while i < n { NBodySystem::advance(bodies, 0.01); i += 1; }
std::io::println(#fmt("%f", NBodySystem::energy(bodies)));
}
// Body::props is a record of floats, so
@ -79,7 +77,7 @@ mod NBodySystem {
let dSquared: float = dx * dx + dy * dy + dz * dz;
let distance: float = llvm::sqrt(dSquared);
let distance: float = libc::sqrt(dSquared);
let mag: float = dt / (dSquared * distance);
bi.vx -= dx * bj.mass * mag;
@ -117,7 +115,7 @@ mod NBodySystem {
dy = bodies[i].y - bodies[j].y;
dz = bodies[i].z - bodies[j].z;
distance = llvm::sqrt(dx * dx + dy * dy + dz * dz);
distance = libc::sqrt(dx * dx + dy * dy + dz * dz);
e -= bodies[i].mass * bodies[j].mass / distance;
j += 1;