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author | Ryan Dahl <ry@tinyclouds.org> | 2010-12-21 10:24:08 -0800 |
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committer | Ryan Dahl <ry@tinyclouds.org> | 2010-12-21 10:24:08 -0800 |
commit | 1a894b39b3c622e7c7d228c049e68b65e4334ee5 (patch) | |
tree | d115a78b28c3b1643154589473c74c75ed039fc7 /deps/v8/src/array.js | |
parent | 6f726cf8c7415d58acb5f6b8493fe53f272b1dd4 (diff) | |
download | node-new-1a894b39b3c622e7c7d228c049e68b65e4334ee5.tar.gz |
Upgrade V8 to 3.0.4
Diffstat (limited to 'deps/v8/src/array.js')
-rw-r--r-- | deps/v8/src/array.js | 69 |
1 files changed, 53 insertions, 16 deletions
diff --git a/deps/v8/src/array.js b/deps/v8/src/array.js index a805157b13..0f1e969f98 100644 --- a/deps/v8/src/array.js +++ b/deps/v8/src/array.js @@ -1,4 +1,4 @@ -// Copyright 2006-2008 the V8 project authors. All rights reserved. +// Copyright 2010 the V8 project authors. All rights reserved. // Redistribution and use in source and binary forms, with or without // modification, are permitted provided that the following conditions are // met: @@ -677,39 +677,76 @@ function ArraySort(comparefn) { function QuickSort(a, from, to) { // Insertion sort is faster for short arrays. - if (to - from <= 22) { + if (to - from <= 10) { InsertionSort(a, from, to); return; } - var pivot_index = $floor($random() * (to - from)) + from; - var pivot = a[pivot_index]; - // Issue 95: Keep the pivot element out of the comparisons to avoid - // infinite recursion if comparefn(pivot, pivot) != 0. - %_SwapElements(a, from, pivot_index); - var low_end = from; // Upper bound of the elements lower than pivot. - var high_start = to; // Lower bound of the elements greater than pivot. + // 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(global_receiver, v0, v1, comparefn); + if (c01 > 0) { + // v1 < v0, so swap them. + var tmp = v0; + v0 = v1; + v1 = tmp; + } // v0 <= v1. + var c02 = %_CallFunction(global_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(global_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[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. - for (var i = from + 1; i < high_start; ) { + partition: for (var i = low_end + 1; i < high_start; i++) { var element = a[i]; var order = %_CallFunction(global_receiver, element, pivot, comparefn); if (order < 0) { %_SwapElements(a, i, low_end); - i++; low_end++; } else if (order > 0) { - high_start--; + do { + high_start--; + if (high_start == i) break partition; + var top_elem = a[high_start]; + order = %_CallFunction(global_receiver, top_elem, pivot, comparefn); + } while (order > 0); %_SwapElements(a, i, high_start); - } else { // order == 0 - i++; + if (order < 0) { + %_SwapElements(a, i, low_end); + low_end++; + } } } QuickSort(a, from, low_end); QuickSort(a, high_start, to); } - // Copies elements in the range 0..length from obj's prototype chain - // to obj itself, if obj has holes. Returns one more than the maximal index + // Copy elements in the range 0..length from obj's prototype chain + // to obj itself, if obj has holes. Return one more than the maximal index // of a prototype property. function CopyFromPrototype(obj, length) { var max = 0; |