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Diffstat (limited to 'vendor/github.com/klauspost/compress/zstd/matchlen_generic.go')
-rw-r--r--vendor/github.com/klauspost/compress/zstd/matchlen_generic.go33
1 files changed, 33 insertions, 0 deletions
diff --git a/vendor/github.com/klauspost/compress/zstd/matchlen_generic.go b/vendor/github.com/klauspost/compress/zstd/matchlen_generic.go
new file mode 100644
index 000000000..57b9c31c0
--- /dev/null
+++ b/vendor/github.com/klauspost/compress/zstd/matchlen_generic.go
@@ -0,0 +1,33 @@
+//go:build !amd64 || appengine || !gc || noasm
+// +build !amd64 appengine !gc noasm
+
+// Copyright 2019+ Klaus Post. All rights reserved.
+// License information can be found in the LICENSE file.
+
+package zstd
+
+import (
+ "encoding/binary"
+ "math/bits"
+)
+
+// matchLen returns the maximum common prefix length of a and b.
+// a must be the shortest of the two.
+func matchLen(a, b []byte) (n int) {
+ for ; len(a) >= 8 && len(b) >= 8; a, b = a[8:], b[8:] {
+ diff := binary.LittleEndian.Uint64(a) ^ binary.LittleEndian.Uint64(b)
+ if diff != 0 {
+ return n + bits.TrailingZeros64(diff)>>3
+ }
+ n += 8
+ }
+
+ for i := range a {
+ if a[i] != b[i] {
+ break
+ }
+ n++
+ }
+ return n
+
+}