glibc/sysdeps/unix/alpha/sysdep.S
Ulrich Drepper af215add0a (EPILOGUE, GPSAVEREG): New.
(LOADGP) [!PIC]: Rewrite to preserve caller's gp.
2003-01-17 19:19:55 +00:00

135 lines
3.2 KiB
ArmAsm

/* Copyright (C) 1993, 1996, 1998, 2002, 2003 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 */
#ifdef PIC
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