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// 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
}
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