summaryrefslogtreecommitdiff
path: root/vendor/github.com/ulikunitz/xz/lzma/bitops.go
diff options
context:
space:
mode:
authorDaniel J Walsh <dwalsh@redhat.com>2018-07-08 07:55:30 -0400
committerAtomic Bot <atomic-devel@projectatomic.io>2018-07-19 18:43:32 +0000
commit98703eb204923f06555605c648fc165a55214520 (patch)
treea407bae8b3489d4f9b0f0d0f228658bbfe95a38e /vendor/github.com/ulikunitz/xz/lzma/bitops.go
parentc020db8cd21cb221cfbe36b264e0ec02999596ed (diff)
downloadpodman-98703eb204923f06555605c648fc165a55214520.tar.gz
podman-98703eb204923f06555605c648fc165a55214520.tar.bz2
podman-98703eb204923f06555605c648fc165a55214520.zip
Vendor in latest code for storage,image, buildah
vendor in containers/storage vendor in containers/image vendor in projectatomic/buildah Signed-off-by: Daniel J Walsh <dwalsh@redhat.com> Closes: #1114 Approved by: mheon
Diffstat (limited to 'vendor/github.com/ulikunitz/xz/lzma/bitops.go')
-rw-r--r--vendor/github.com/ulikunitz/xz/lzma/bitops.go45
1 files changed, 45 insertions, 0 deletions
diff --git a/vendor/github.com/ulikunitz/xz/lzma/bitops.go b/vendor/github.com/ulikunitz/xz/lzma/bitops.go
new file mode 100644
index 000000000..e9bab0199
--- /dev/null
+++ b/vendor/github.com/ulikunitz/xz/lzma/bitops.go
@@ -0,0 +1,45 @@
+// Copyright 2014-2017 Ulrich Kunitz. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package lzma
+
+/* Naming conventions follows the CodeReviewComments in the Go Wiki. */
+
+// ntz32Const is used by the functions NTZ and NLZ.
+const ntz32Const = 0x04d7651f
+
+// ntz32Table is a helper table for de Bruijn algorithm by Danny Dubé.
+// See Henry S. Warren, Jr. "Hacker's Delight" section 5-1 figure 5-26.
+var ntz32Table = [32]int8{
+ 0, 1, 2, 24, 3, 19, 6, 25,
+ 22, 4, 20, 10, 16, 7, 12, 26,
+ 31, 23, 18, 5, 21, 9, 15, 11,
+ 30, 17, 8, 14, 29, 13, 28, 27,
+}
+
+// ntz32 computes the number of trailing zeros for an unsigned 32-bit integer.
+func ntz32(x uint32) int {
+ if x == 0 {
+ return 32
+ }
+ x = (x & -x) * ntz32Const
+ return int(ntz32Table[x>>27])
+}
+
+// nlz32 computes the number of leading zeros for an unsigned 32-bit integer.
+func nlz32(x uint32) int {
+ // Smear left most bit to the right
+ x |= x >> 1
+ x |= x >> 2
+ x |= x >> 4
+ x |= x >> 8
+ x |= x >> 16
+ // Use ntz mechanism to calculate nlz.
+ x++
+ if x == 0 {
+ return 0
+ }
+ x *= ntz32Const
+ return 32 - int(ntz32Table[x>>27])
+}