glibc/sysdeps/sparc/__longjmp.S

60 lines
2.2 KiB
ArmAsm

/* Copyright (C) 1991, 1993, 1996 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 Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
#include <sysdep.h>
#define _ASM 1
#include <jmp_buf.h>
#define ENV(reg) [%g1 + (reg * 4)]
ENTRY (__longjmp)
/* Store our arguments in global registers so we can still
use them while unwinding frames and their register windows. */
mov %o0, %g1 /* ENV in %g1 */
orcc %o1, %g0, %g6 /* VAL in %g6 */
be,a 0f /* Branch if zero; else skip delay slot. */
mov 1, %g6 /* Delay slot only hit if zero: VAL = 1. */
0:
/* Cache target FP in register %g7. */
ld ENV (JB_FP), %g7
/* Now we will loop, unwinding the register windows up the stack
until the restored %fp value matches the target value in %g7. */
loop: cmp %fp, %g7 /* Have we reached the target frame? */
bl,a loop /* Loop while current fp is below target. */
restore /* Unwind register window in delay slot. */
be,a found /* Better have hit it exactly. */
ld ENV (JB_SP), %o0 /* Delay slot: extract target SP. */
bogus: /* Get here only if the jmp_buf or stack is clobbered. */
call C_SYMBOL_NAME (abort)
nop
unimp 0
found: /* We have unwound register windows so %fp matches the target. */
cmp %o0, %sp /* Check jmp_buf SP vs register window. */
bge,a sp_ok /* Saved must not be deeper than register. */
mov %o0, %sp /* OK, install new SP. */
b,a bogus /* Bogus, we lose. */
sp_ok: ld ENV (JB_PC), %o0 /* Extract target return PC. */
jmp %o0 + 8 /* Return there. */
mov %g6, %o0 /* Delay slot: set return value. */