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1d765b77a0
The current fastlog2 testing checks all 64M values in the domain of interest, which is too much for platforms with no native floating point. Reduce testing under testing.Short() to speed up builds for those platforms. Related to #12620 Change-Id: Ie5dcd408724ba91c3b3fcf9ba0dddedb34706cd1 Reviewed-on: https://go-review.googlesource.com/15830 Reviewed-by: Keith Randall <khr@golang.org> Reviewed-by: Joel Sing <jsing@google.com> Reviewed-by: Minux Ma <minux@golang.org> Run-TryBot: Minux Ma <minux@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
35 lines
785 B
Go
35 lines
785 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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