diff options
Diffstat (limited to 'deps/v8/src/array.js')
-rw-r--r-- | deps/v8/src/array.js | 151 |
1 files changed, 88 insertions, 63 deletions
diff --git a/deps/v8/src/array.js b/deps/v8/src/array.js index a1cc5b6a7d..1cedd8d476 100644 --- a/deps/v8/src/array.js +++ b/deps/v8/src/array.js @@ -777,78 +777,103 @@ function ArraySort(comparefn) { } }; - var QuickSort = function QuickSort(a, from, to) { - // Insertion sort is faster for short arrays. - if (to - from <= 10) { - InsertionSort(a, from, to); - return; + var GetThirdIndex = function(a, from, to) { + var t_array = []; + // Use both 'from' and 'to' to determine the pivot candidates. + var increment = 200 + ((to - from) & 15); + for (var i = from + 1; i < to - 1; i += increment) { + t_array.push([i, a[i]]); } - // Find a pivot as the median of first, last and middle element. - var v0 = a[from]; - var v1 = a[to - 1]; - var middle_index = from + ((to - from) >> 1); - var v2 = a[middle_index]; - var c01 = %_CallFunction(receiver, v0, v1, comparefn); - if (c01 > 0) { - // v1 < v0, so swap them. - var tmp = v0; - v0 = v1; - v1 = tmp; - } // v0 <= v1. - var c02 = %_CallFunction(receiver, v0, v2, comparefn); - if (c02 >= 0) { - // v2 <= v0 <= v1. - var tmp = v0; - v0 = v2; - v2 = v1; - v1 = tmp; - } else { - // v0 <= v1 && v0 < v2 - var c12 = %_CallFunction(receiver, v1, v2, comparefn); - if (c12 > 0) { - // v0 <= v2 < v1 - var tmp = v1; - v1 = v2; - v2 = tmp; + t_array.sort(function(a, b) { + return %_CallFunction(receiver, a[1], b[1], comparefn) } ); + var third_index = t_array[t_array.length >> 1][0]; + return third_index; + } + + var QuickSort = function QuickSort(a, from, to) { + var third_index = 0; + while (true) { + // Insertion sort is faster for short arrays. + if (to - from <= 10) { + InsertionSort(a, from, to); + return; } - } - // v0 <= v1 <= v2 - a[from] = v0; - a[to - 1] = v2; - var pivot = v1; - var low_end = from + 1; // Upper bound of elements lower than pivot. - var high_start = to - 1; // Lower bound of elements greater than pivot. - a[middle_index] = a[low_end]; - a[low_end] = pivot; - - // From low_end to i are elements equal to pivot. - // From i to high_start are elements that haven't been compared yet. - partition: for (var i = low_end + 1; i < high_start; i++) { - var element = a[i]; - var order = %_CallFunction(receiver, element, pivot, comparefn); - if (order < 0) { - a[i] = a[low_end]; - a[low_end] = element; - low_end++; - } else if (order > 0) { - do { - high_start--; - if (high_start == i) break partition; - var top_elem = a[high_start]; - order = %_CallFunction(receiver, top_elem, pivot, comparefn); - } while (order > 0); - a[i] = a[high_start]; - a[high_start] = element; + if (to - from > 1000) { + third_index = GetThirdIndex(a, from, to); + } else { + third_index = from + ((to - from) >> 1); + } + // Find a pivot as the median of first, last and middle element. + var v0 = a[from]; + var v1 = a[to - 1]; + var v2 = a[third_index]; + var c01 = %_CallFunction(receiver, v0, v1, comparefn); + if (c01 > 0) { + // v1 < v0, so swap them. + var tmp = v0; + v0 = v1; + v1 = tmp; + } // v0 <= v1. + var c02 = %_CallFunction(receiver, v0, v2, comparefn); + if (c02 >= 0) { + // v2 <= v0 <= v1. + var tmp = v0; + v0 = v2; + v2 = v1; + v1 = tmp; + } else { + // v0 <= v1 && v0 < v2 + var c12 = %_CallFunction(receiver, v1, v2, comparefn); + if (c12 > 0) { + // v0 <= v2 < v1 + var tmp = v1; + v1 = v2; + v2 = tmp; + } + } + // v0 <= v1 <= v2 + a[from] = v0; + a[to - 1] = v2; + var pivot = v1; + var low_end = from + 1; // Upper bound of elements lower than pivot. + var high_start = to - 1; // Lower bound of elements greater than pivot. + a[third_index] = a[low_end]; + a[low_end] = pivot; + + // From low_end to i are elements equal to pivot. + // From i to high_start are elements that haven't been compared yet. + partition: for (var i = low_end + 1; i < high_start; i++) { + var element = a[i]; + var order = %_CallFunction(receiver, element, pivot, comparefn); if (order < 0) { - element = a[i]; a[i] = a[low_end]; a[low_end] = element; low_end++; + } else if (order > 0) { + do { + high_start--; + if (high_start == i) break partition; + var top_elem = a[high_start]; + order = %_CallFunction(receiver, top_elem, pivot, comparefn); + } while (order > 0); + a[i] = a[high_start]; + a[high_start] = element; + if (order < 0) { + element = a[i]; + a[i] = a[low_end]; + a[low_end] = element; + low_end++; + } } } + if (to - high_start < low_end - from) { + QuickSort(a, high_start, to); + to = low_end; + } else { + QuickSort(a, from, low_end); + from = high_start; + } } - QuickSort(a, from, low_end); - QuickSort(a, high_start, to); }; // Copy elements in the range 0..length from obj's prototype chain |