github.com/huandu/go@v0.0.0-20151114150818-04e615e41150/misc/cgo/test/issue9400/asm_arm64.s (about)

     1  // Copyright 2014 The Go Authors.  All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  // +build !gccgo
     6  
     7  #include "textflag.h"
     8  
     9  TEXT ·RewindAndSetgid(SB),NOSPLIT,$-8-0
    10  	// Save link register
    11  	MOVD	R30, R9
    12  
    13  	// Rewind stack pointer so anything that happens on the stack
    14  	// will clobber the test pattern created by the caller
    15  	ADD	$(1024 * 8), RSP
    16  
    17  	// Ask signaller to setgid
    18  	MOVD	$·Baton(SB), R0
    19  	MOVD	$1, R1
    20  storeloop:
    21  	LDAXRW	(R0), R2
    22  	STLXRW	R1, (R0), R3
    23  	CBNZ	R3, storeloop
    24  
    25  	// Wait for setgid completion
    26  	MOVW	$0, R1
    27  	MOVW	$0, R2
    28  loop:
    29  	LDAXRW	(R0), R3
    30  	CMPW	R1, R3
    31  	BNE	loop
    32  	STLXRW	R2, (R0), R3
    33  	CBNZ	R3, loop
    34  
    35  	// Restore stack
    36  	SUB	$(1024 * 8), RSP
    37  
    38  	MOVD	R9, R30
    39  	RET