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519474451a
This is a subset of https://golang.org/cl/20022 with only the copyright header lines, so the next CL will be smaller and more reviewable. Go policy has been single space after periods in comments for some time. The copyright header template at: https://golang.org/doc/contribute.html#copyright also uses a single space. Make them all consistent. Change-Id: Icc26c6b8495c3820da6b171ca96a74701b4a01b0 Reviewed-on: https://go-review.googlesource.com/20111 Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org> Reviewed-by: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org>
33 lines
947 B
Go
33 lines
947 B
Go
// Copyright 2014 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// +build ppc64 ppc64le
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// +build linux
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package runtime
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import "unsafe"
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// On ppc64, Linux limits the user address space to 46 bits (see
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// TASK_SIZE_USER64 in the Linux kernel). This has grown over time,
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// so here we allow 48 bit addresses.
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//
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// In addition to the 16 bits taken from the top, we can take 3 from the
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// bottom, because node must be pointer-aligned, giving a total of 19 bits
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// of count.
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const (
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addrBits = 48
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cntBits = 64 - addrBits + 3
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)
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func lfstackPack(node *lfnode, cnt uintptr) uint64 {
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return uint64(uintptr(unsafe.Pointer(node)))<<(64-addrBits) | uint64(cnt&(1<<cntBits-1))
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}
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func lfstackUnpack(val uint64) (node *lfnode, cnt uintptr) {
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node = (*lfnode)(unsafe.Pointer(uintptr(val >> cntBits << 3)))
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cnt = uintptr(val & (1<<cntBits - 1))
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return
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}
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