github.com/SandwichDev/go-internals@v0.0.0-20210605002614-12311ac6b2c5/bytealg/index_amd64.go (about)

     1  // Copyright 2018 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package bytealg
     6  
     7  import "github.com/SandwichDev/go-internals/cpu"
     8  
     9  const MaxBruteForce = 64
    10  
    11  func init() {
    12  	if cpu.X86.HasAVX2 {
    13  		MaxLen = 63
    14  	} else {
    15  		MaxLen = 31
    16  	}
    17  }
    18  
    19  // Cutover reports the number of failures of IndexByte we should tolerate
    20  // before switching over to Index.
    21  // n is the number of bytes processed so far.
    22  // See the bytes.Index implementation for details.
    23  func Cutover(n int) int {
    24  	// 1 error per 8 characters, plus a few slop to start.
    25  	return (n + 16) / 8
    26  }