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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>
50 lines
1.5 KiB
ArmAsm
50 lines
1.5 KiB
ArmAsm
// 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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#include "go_asm.h"
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#include "go_tls.h"
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#include "funcdata.h"
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#include "textflag.h"
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// We have to resort to TLS variable to save g (R30).
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// One reason is that external code might trigger
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// SIGSEGV, and our runtime.sigtramp don't even know we
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// are in external code, and will continue to use R30,
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// this might well result in another SIGSEGV.
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// save_g saves the g register into pthread-provided
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// thread-local memory, so that we can call externally compiled
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// ppc64 code that will overwrite this register.
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//
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// If !iscgo, this is a no-op.
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//
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// NOTE: setg_gcc<> assume this clobbers only R31.
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TEXT runtime·save_g(SB),NOSPLIT|NOFRAME,$0-0
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MOVB runtime·iscgo(SB), R31
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CMP R31, $0
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BEQ nocgo
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MOVD runtime·tls_g(SB), R31
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MOVD g, 0(R13)(R31*1)
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nocgo:
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RET
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// load_g loads the g register from pthread-provided
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// thread-local memory, for use after calling externally compiled
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// ppc64 code that overwrote those registers.
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//
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// This is never called directly from C code (it doesn't have to
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// follow the C ABI), but it may be called from a C context, where the
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// usual Go registers aren't set up.
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//
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// NOTE: _cgo_topofstack assumes this only clobbers g (R30), and R31.
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TEXT runtime·load_g(SB),NOSPLIT|NOFRAME,$0-0
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MOVD runtime·tls_g(SB), R31
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MOVD 0(R13)(R31*1), g
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RET
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GLOBL runtime·tls_g+0(SB), TLSBSS, $8
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