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-rw-r--r--src/internal/bytealg/index_amd64.go26
1 files changed, 26 insertions, 0 deletions
diff --git a/src/internal/bytealg/index_amd64.go b/src/internal/bytealg/index_amd64.go
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+++ b/src/internal/bytealg/index_amd64.go
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+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package bytealg
+
+import "internal/cpu"
+
+const MaxBruteForce = 64
+
+func init() {
+ if cpu.X86.HasAVX2 {
+ MaxLen = 63
+ } else {
+ MaxLen = 31
+ }
+}
+
+// Cutover reports the number of failures of IndexByte we should tolerate
+// before switching over to Index.
+// n is the number of bytes processed so far.
+// See the bytes.Index implementation for details.
+func Cutover(n int) int {
+ // 1 error per 8 characters, plus a few slop to start.
+ return (n + 16) / 8
+}