// Copyright 2014 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 runtime import "unsafe" // On AMD64, virtual addresses are 48-bit numbers sign extended to 64.// We shift the address left 16 to eliminate the sign extended part and make// room in the bottom for the count.// In addition to the 16 bits taken from the top, we can take 3 from the// bottom, because node must be pointer-aligned, giving a total of 19 bits// of count. func lfstackPack(node *lfnode, cnt uintptr) uint64 {	return uint64(uintptr(unsafe.Pointer(node)))<<16 | uint64(cnt&(1<<19-1))} func lfstackUnpack(val uint64) (node *lfnode, cnt uintptr) {	node = (*lfnode)(unsafe.Pointer(uintptr(int64(val) >> 19 << 3)))	cnt = uintptr(val & (1<<19 - 1))	return}