forked from mirror/brotli
Optimize log2FloorNonZero with math/bits.
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ec682fbe0a
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16
fast_log.go
16
fast_log.go
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@ -1,6 +1,9 @@
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package brotli
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import "math"
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import (
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"math"
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"math/bits"
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)
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/* Copyright 2013 Google Inc. All Rights Reserved.
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@ -11,16 +14,7 @@ import "math"
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/* Utilities for fast computation of logarithms. */
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func log2FloorNonZero(n uint) uint32 {
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/* TODO: generalize and move to platform.h */
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var result uint32 = 0
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for {
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n >>= 1
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if n == 0 {
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break
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}
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result++
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}
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return result
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return uint32(bits.Len(n)) - 1
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}
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/* A lookup table for small values of log2(int) to be used in entropy
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