.gitignore added

[dotfiles/.git] / .config / coc / extensions / coc-go-data / tools / pkg / mod / golang.org / x / tools@v0.1.1-0.20210319172145-bda8f5cee399 / container / intsets / popcnt_generic.go

diff --git a/.config/coc/extensions/coc-go-data/tools/pkg/mod/golang.org/x/tools@v0.1.1-0.20210319172145-bda8f5cee399/container/intsets/popcnt_generic.go b/.config/coc/extensions/coc-go-data/tools/pkg/mod/golang.org/x/tools@v0.1.1-0.20210319172145-bda8f5cee399/container/intsets/popcnt_generic.go
new file mode 100644 (file)
index 0000000..caffedc
--- /dev/null
+++ b/.config/coc/extensions/coc-go-data/tools/pkg/mod/golang.org/x/tools@v0.1.1-0.20210319172145-bda8f5cee399/container/intsets/popcnt_generic.go
@@ -0,0 +1,34 @@
+// Copyright 2015 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.
+
+//go:build (!amd64 || appengine) && !gccgo
+// +build !amd64 appengine
+// +build !gccgo
+
+package intsets
+
+import "runtime"
+
+// We compared three algorithms---Hacker's Delight, table lookup,
+// and AMD64's SSE4.1 hardware POPCNT---on a 2.67GHz Xeon X5550.
+//
+// % GOARCH=amd64 go test -run=NONE -bench=Popcount
+// POPCNT               5.12 ns/op
+// Table                8.53 ns/op
+// HackersDelight       9.96 ns/op
+//
+// % GOARCH=386 go test -run=NONE -bench=Popcount
+// Table               10.4  ns/op
+// HackersDelight       5.23 ns/op
+//
+// (AMD64's ABM1 hardware supports ntz and nlz too,
+// but they aren't critical.)
+
+// popcount returns the population count (number of set bits) of x.
+func popcount(x word) int {
+       if runtime.GOARCH == "386" {
+               return popcountHD(uint32(x))
+       }
+       return popcountTable(x)
+}