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De-abstract std::sort:qsort3, which uses only the trait-based lt/eq.

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quick_sort3 was converted from fn parameters to traits in d9cdddeb, but
was still passing around closures over core::cmp::{eq,lt} internally,
and LLVM doesn't and/or can't pick up that they're effectively constant.

Reduces time spent to sort a large random ~[uint] by 16% in my testing.
This commit is contained in:
Jed Davis 2012-08-27 21:17:42 -07:00 • committed by Niko Matsakis
parent 206edf66c9
commit c5528198ab
1 changed files with 8 additions and 9 deletions
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17
src/libstd/sort.rs
View file

@ -95,8 +95,7 @@ fn quick_sort<T: copy>(compare_func: le<T>, arr: ~[mut T]) {
qsort::<T>(compare_func, arr, 0u, len::<T>(arr) - 1u);
}
fn qsort3<T: copy>(compare_func_lt: le<T>, compare_func_eq: le<T>,
arr: ~[mut T], left: int, right: int) {
fn qsort3<T: copy Ord Eq>(arr: ~[mut T], left: int, right: int) {
if right <= left { return; }
let v: T = arr[right];
let mut i: int = left - 1;
@ -105,19 +104,19 @@ fn qsort3<T: copy>(compare_func_lt: le<T>, compare_func_eq: le<T>,
let mut q: int = j;
loop {
i += 1;
while compare_func_lt(&arr[i], &v) { i += 1; }
while arr[i] < v { i += 1; }
j -= 1;
while compare_func_lt(&v, &arr[j]) {
while v < arr[j] {
if j == left { break; }
j -= 1;
}
if i >= j { break; }
arr[i] <-> arr[j];
if compare_func_eq(&arr[i], &v) {
if arr[i] == v {
p += 1;
arr[p] <-> arr[i];
}
if compare_func_eq(&v, &arr[j]) {
if v == arr[j] {
q -= 1;
arr[j] <-> arr[q];
}
@ -139,8 +138,8 @@ fn qsort3<T: copy>(compare_func_lt: le<T>, compare_func_eq: le<T>,
i += 1;
if k == 0 { break; }
}
qsort3::<T>(compare_func_lt, compare_func_eq, arr, left, j);
qsort3::<T>(compare_func_lt, compare_func_eq, arr, i, right);
qsort3::<T>(arr, left, j);
qsort3::<T>(arr, i, right);
}
/**
@ -155,7 +154,7 @@ fn qsort3<T: copy>(compare_func_lt: le<T>, compare_func_eq: le<T>,
*/
fn quick_sort3<T: copy Ord Eq>(arr: ~[mut T]) {
if arr.len() <= 1 { return; }
qsort3(core::cmp::lt, core::cmp::eq, arr, 0, (arr.len() - 1) as int);
qsort3(arr, 0, (arr.len() - 1) as int);
}
#[cfg(test)]