github.com/riscv/riscv-go@v0.0.0-20200123204226-124ebd6fcc8e/misc/cgo/test/issue9400/asm_arm.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 cas<>(SB),NOSPLIT,$0
    10  	MOVW	$0xffff0fc0, R15 // R15 is PC
    11  
    12  TEXT ·RewindAndSetgid(SB),NOSPLIT,$-4-0
    13  	// Save link register
    14  	MOVW	R14, R4
    15  
    16  	// Rewind stack pointer so anything that happens on the stack
    17  	// will clobber the test pattern created by the caller
    18  	ADD	$(1024 * 8), R13
    19  
    20  	// Ask signaller to setgid
    21  	MOVW	$·Baton(SB), R2
    22  storeloop:
    23  	MOVW	0(R2), R0
    24  	MOVW	$1, R1
    25  	BL	cas<>(SB)
    26  	BCC	storeloop
    27  
    28  	// Wait for setgid completion
    29  loop:
    30  	MOVW	$0, R0
    31  	MOVW	$0, R1
    32  	BL	cas<>(SB)
    33  	BCC	loop
    34  
    35  	// Restore stack
    36  	SUB	$(1024 * 8), R13
    37  
    38  	MOVW	R4, R14
    39  	RET