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64 lines
1.6 KiB
64 lines
1.6 KiB
// Copyright 2011 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// This benchmark, taken from the shootout, tests garbage collector
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// performance by generating and discarding large binary trees.
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package go1
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import "testing"
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type binaryNode struct {
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item int
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left, right *binaryNode
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}
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func bottomUpTree(item, depth int) *binaryNode {
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if depth <= 0 {
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return &binaryNode{item: item}
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}
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return &binaryNode{item, bottomUpTree(2*item-1, depth-1), bottomUpTree(2*item, depth-1)}
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}
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func (n *binaryNode) itemCheck() int {
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if n.left == nil {
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return n.item
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}
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return n.item + n.left.itemCheck() - n.right.itemCheck()
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}
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const minDepth = 4
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func binarytree(n int) {
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maxDepth := n
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if minDepth+2 > n {
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maxDepth = minDepth + 2
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}
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stretchDepth := maxDepth + 1
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check := bottomUpTree(0, stretchDepth).itemCheck()
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//fmt.Printf("stretch tree of depth %d\t check: %d\n", stretchDepth, check)
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longLivedTree := bottomUpTree(0, maxDepth)
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for depth := minDepth; depth <= maxDepth; depth += 2 {
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iterations := 1 << uint(maxDepth-depth+minDepth)
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check = 0
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for i := 1; i <= iterations; i++ {
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check += bottomUpTree(i, depth).itemCheck()
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check += bottomUpTree(-i, depth).itemCheck()
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}
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//fmt.Printf("%d\t trees of depth %d\t check: %d\n", iterations*2, depth, check)
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}
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longLivedTree.itemCheck()
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//fmt.Printf("long lived tree of depth %d\t check: %d\n", maxDepth, longLivedTree.itemCheck())
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}
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func BenchmarkBinaryTree17(b *testing.B) {
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for i := 0; i < b.N; i++ {
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binarytree(17)
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}
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}
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