summaryrefslogtreecommitdiff
path: root/sysdeps/unix/sysv/linux/alpha/makecontext.S
blob: 45f0f5c7c6a679b704f2c4096a06a71e2dacb708 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
/* Copyright (C) 2004-2019 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library.  If not, see
   <http://www.gnu.org/licenses/>.  */

#include <sysdep.h>
#include <ucontext-offsets.h>


ENTRY(__makecontext)
	ldgp	$29, 0($27)
#ifdef PROF
	.set noat
	lda     AT, _mcount
	jsr     AT, (AT), _mcount
	.set at
#endif
	.prologue 1

	/* Compute top of stack, including arguments.  */
	ldq	$1, UC_STACK+SS_SP($16)
	ldq	$2, UC_STACK+SS_SIZE($16)
	addq	$1, $2, $8
	subq	$18, 6, $1
	cmovlt	$1, 0, $1
	s8addq	$1, 0, $2
	subq	$8, $2, $8

	/* Copy all parameters.  Switch statement header here.  */
	ldah	$3, $jumptable($29)	!gprelhigh
	cmple	$18, 6, $1
	mov	$18, $2
	cmoveq	$1, 7, $2
	s4addq	$2, $3, $3
	ldl	$4, $jumptable($3)	!gprellow
	addq	$4, $29, $4
	jmp	$31, ($4), $args1

	.section .rodata
	.align	2
$jumptable:
	.gprel32  $args0
	.gprel32  $args1
	.gprel32  $args2
	.gprel32  $args3
	.gprel32  $args4
	.gprel32  $args5
	.gprel32  $args6
	.gprel32  $argsN
	.text

	/* Here we process arguments 7 through N.  This is a straight
	   stack-to-stack copy.  */
	.align	4
$argsN:
	subq	$18, 6, $1
	lda	$2, 0($8)
	lda	$3, 3*8($30)
	.align	4
1:
	ldq	$0, 0($3)
	subq	$1, 1, $1
	lda	$3, 8($3)
	stq	$0, 0($2)
	lda	$2, 8($2)
	bne	$1, 1b

	/* Here we process arguments 6 through 0.  This involves
	   copying into the register save areas of the ucontext.  */
	.align	4
$args6:
	ldq	$0, 2*8($30)
	stq	$0, UC_SIGCTX+SC_REGS+21*8($16)
	unop
	stq	$0, UC_SIGCTX+SC_FPREGS+21*8($16)
$args5:
	ldq	$0, 1*8($30)
	stq	$0, UC_SIGCTX+SC_REGS+20*8($16)
	unop
	stq	$0, UC_SIGCTX+SC_FPREGS+20*8($16)
$args4:
	ldq	$0, 0*8($30)
	stq	$0, UC_SIGCTX+SC_REGS+19*8($16)
	unop
	stq	$0, UC_SIGCTX+SC_FPREGS+19*8($16)
$args3:
	unop
	stq	$21, UC_SIGCTX+SC_REGS+18*8($16)
	unop
	stt	$f21, UC_SIGCTX+SC_FPREGS+18*8($16)
$args2:
	unop
	stq	$20, UC_SIGCTX+SC_REGS+17*8($16)
	unop
	stt	$f20, UC_SIGCTX+SC_FPREGS+17*8($16)
$args1:
	unop
	stq	$19, UC_SIGCTX+SC_REGS+16*8($16)
	unop
	stt	$f19, UC_SIGCTX+SC_FPREGS+16*8($16)
$args0:

	/* Set up the registers ready to invoke __startcontext.
	   We seed $27 with the target function address, and $9
	   with the link from ucp.  */
	ldah	$0, __startcontext($29)		!gprelhigh
	ldq	$1, UC_LINK($16)
	lda	$0, __startcontext($0)		!gprellow
	stq	$17, UC_SIGCTX+SC_REGS+27*8($16)
	stq	$8, UC_SIGCTX+SC_REGS+30*8($16)
	stq	$0, UC_SIGCTX+SC_PC($16)
	stq	$1, UC_SIGCTX+SC_REGS+9*8($16)

	/* No return value from makecontext.  */
	ret

END(__makecontext)
weak_alias (__makecontext, makecontext)

/* This function is where a new makecontext "thread" begins life.
   We have already set up $27 for calling the target function, and
   we've set $9 to the UC_LINK of the parent context.

   If the function returns, we either jump to the linked context
   (if non-null) or exit.  */

	.align	4
	.ent	__startcontext
__startcontext:
	.frame $31, 0, $31, 0
	.prologue 0

	jsr	$26, ($27), 0
	ldgp	$29, 0($26)
	mov	$9, $16
	beq	$9, 1f

#ifdef PIC
	bsr	$26, __setcontext		!samegp
1:	mov	$31, $16
	bsr	$26, HIDDEN_JUMPTARGET(exit)	!samegp
#else
	jsr	$26, __setcontext
	ldgp	$29, 0($26)
1:	mov	$31, $16
	jsr	$26, HIDDEN_JUMPTARGET(exit)
#endif

	halt

	.end __startcontext