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519474451a
This is a subset of https://golang.org/cl/20022 with only the copyright header lines, so the next CL will be smaller and more reviewable. Go policy has been single space after periods in comments for some time. The copyright header template at: https://golang.org/doc/contribute.html#copyright also uses a single space. Make them all consistent. Change-Id: Icc26c6b8495c3820da6b171ca96a74701b4a01b0 Reviewed-on: https://go-review.googlesource.com/20111 Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org> Reviewed-by: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org>
35 lines
784 B
Go
35 lines
784 B
Go
// Copyright 2015 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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package runtime_test
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import (
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"math"
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"runtime"
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"testing"
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)
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func TestFastLog2(t *testing.T) {
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// Compute the euclidean distance between math.Log2 and the FastLog2
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// implementation over the range of interest for heap sampling.
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const randomBitCount = 26
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var e float64
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inc := 1
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if testing.Short() {
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// Check 1K total values, down from 64M.
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inc = 1 << 16
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}
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for i := 1; i < 1<<randomBitCount; i += inc {
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l, fl := math.Log2(float64(i)), runtime.Fastlog2(float64(i))
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d := l - fl
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e += d * d
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}
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e = math.Sqrt(e)
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if e > 1.0 {
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t.Fatalf("imprecision on fastlog2 implementation, want <=1.0, got %f", e)
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}
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}
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