Giant blob of minor changes

[dotfiles/.git] / .config / coc / extensions / coc-go-data / tools / pkg / mod / golang.org / x / tools@v0.0.0-20201028153306-37f0764111ff / container / intsets / util.go

diff --git a/.config/coc/extensions/coc-go-data/tools/pkg/mod/golang.org/x/tools@v0.0.0-20201028153306-37f0764111ff/container/intsets/util.go b/.config/coc/extensions/coc-go-data/tools/pkg/mod/golang.org/x/tools@v0.0.0-20201028153306-37f0764111ff/container/intsets/util.go
new file mode 100644 (file)
index 0000000..dd1db86
--- /dev/null
+++ b/.config/coc/extensions/coc-go-data/tools/pkg/mod/golang.org/x/tools@v0.0.0-20201028153306-37f0764111ff/container/intsets/util.go
@@ -0,0 +1,84 @@
+// Copyright 2013 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 intsets
+
+// From Hacker's Delight, fig 5.2.
+func popcountHD(x uint32) int {
+       x -= (x >> 1) & 0x55555555
+       x = (x & 0x33333333) + ((x >> 2) & 0x33333333)
+       x = (x + (x >> 4)) & 0x0f0f0f0f
+       x = x + (x >> 8)
+       x = x + (x >> 16)
+       return int(x & 0x0000003f)
+}
+
+var a [1 << 8]byte
+
+func init() {
+       for i := range a {
+               var n byte
+               for x := i; x != 0; x >>= 1 {
+                       if x&1 != 0 {
+                               n++
+                       }
+               }
+               a[i] = n
+       }
+}
+
+func popcountTable(x word) int {
+       return int(a[byte(x>>(0*8))] +
+               a[byte(x>>(1*8))] +
+               a[byte(x>>(2*8))] +
+               a[byte(x>>(3*8))] +
+               a[byte(x>>(4*8))] +
+               a[byte(x>>(5*8))] +
+               a[byte(x>>(6*8))] +
+               a[byte(x>>(7*8))])
+}
+
+// nlz returns the number of leading zeros of x.
+// From Hacker's Delight, fig 5.11.
+func nlz(x word) int {
+       x |= (x >> 1)
+       x |= (x >> 2)
+       x |= (x >> 4)
+       x |= (x >> 8)
+       x |= (x >> 16)
+       x |= (x >> 32)
+       return popcount(^x)
+}
+
+// ntz returns the number of trailing zeros of x.
+// From Hacker's Delight, fig 5.13.
+func ntz(x word) int {
+       if x == 0 {
+               return bitsPerWord
+       }
+       n := 1
+       if bitsPerWord == 64 {
+               if (x & 0xffffffff) == 0 {
+                       n = n + 32
+                       x = x >> 32
+               }
+       }
+       if (x & 0x0000ffff) == 0 {
+               n = n + 16
+               x = x >> 16
+       }
+       if (x & 0x000000ff) == 0 {
+               n = n + 8
+               x = x >> 8
+       }
+       if (x & 0x0000000f) == 0 {
+               n = n + 4
+               x = x >> 4
+       }
+       if (x & 0x00000003) == 0 {
+               n = n + 2
+               x = x >> 2
+       }
+       return n - int(x&1)
+}