about summary refs log tree commit diff
path: root/sysdeps/unix/alpha/sysdep.S
blob: c67a6542f67a7b7bca5d43e0c0926dc11ffe3239 (plain) (blame)
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
/* Copyright (C) 1993, 1996, 1998, 2002, 2003, 2004
   Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Brendan Kehoe (brendan@zen.org).

   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, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#include <sysdep.h>
#include <features.h>

#if defined(__ELF__) && defined(PIC)
	/* Put this at the end of libc's text segment so that all of
	   the direct branches from the syscalls are forward, and 
	   thus predicted not taken.  */
	.section .text.last, "ax", @progbits
#else
	.text
#endif

#ifdef PIC
	/* When building a shared library, we branch here without
	   having loaded the GP.  Nor, since it was a direct branch,
	   have we loaded PV with our address.  Do both.  */
# define LOADGP		br pv, 1f; 1: ldgp gp, 0(pv)
# define PROLOGUE	.prologue 0
# define EPILOGUE
#else
	/* When building the static library, we tail call here from
	   elsewhere, which might use a different GP.  The entertaining
	   part is that we have to return with the GP of our caller
	   in place, so that linker relaxation works properly.  */
	/* ??? This is so ugly.  Consider always putting the errno
	   setting code with the syscall in the static case.  */
# define GPSAVEREG	t10
# define LOADGP		ldah	t11, 0(pv) !gpdisp!1;		\
			br	1f;				\
			.subsection 2;				\
			1: mov	gp, GPSAVEREG;			\
			lda	gp, 0(t11) !gpdisp!1;		\
			br	2f;				\
			.previous;				\
			mov	gp, GPSAVEREG;			\
			2:
# define PROLOGUE	.prologue 1
# define EPILOGUE	mov	GPSAVEREG, gp
#endif

	.align 4
	.globl __syscall_error
	.ent __syscall_error
__syscall_error:

#if defined(_LIBC_REENTRANT) && USE___THREAD

#ifndef NOT_IN_libc
# define SYSCALL_ERROR_ERRNO __libc_errno
#else
# define SYSCALL_ERROR_ERRNO errno
#endif

	LOADGP
	PROLOGUE
	mov	v0, t0
	call_pal PAL_rduniq
	ldq	t1, SYSCALL_ERROR_ERRNO(gp) !gottprel
	addq	v0, t1, v0
	stl	t0, 0(v0)
	lda	v0, -1
	EPILOGUE
	ret

#elif defined(_LIBC_REENTRANT)

	LOADGP
	lda	sp, -32(sp)
	.frame	sp, 32, ra, 0
	stq	ra, 0(sp)
	stq	v0, 8(sp)
#ifdef GPSAVEREG
	stq	GPSAVEREG, 16(sp)
#endif
	.mask	0x4000001, -32
	PROLOGUE

	/* Find our per-thread errno address  */
#if defined PIC && !defined IS_IN_librt
	bsr	ra, __errno_location	!samegp
#else
	jsr	ra, __errno_location
#ifndef GPSAVEREG
	ldgp	gp, 0(ra)
#endif
#endif

	/* Store the error value.  */
	ldq	t0, 8(sp)
	stl	t0, 0(v0)

	/* And kick back a -1.  */
	ldi	v0, -1

#ifdef GPSAVEREG
	ldq	GPSAVEREG, 16(sp)
#endif
	ldq	ra, 0(sp)
	lda	sp, 32(sp)
	EPILOGUE
	ret

#else

	LOADGP
	PROLOGUE
	stl	v0, errno
	lda	v0, -1
	EPILOGUE
	ret

#endif

	.subsection 3
	.end __syscall_error