diff options
Diffstat (limited to 'libc/sysdeps/linux/sparc/__longjmp.S')
| -rw-r--r-- | libc/sysdeps/linux/sparc/__longjmp.S | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/sparc/__longjmp.S b/libc/sysdeps/linux/sparc/__longjmp.S new file mode 100644 index 000000000..d0f8c73be --- /dev/null +++ b/libc/sysdeps/linux/sparc/__longjmp.S @@ -0,0 +1,92 @@ +/* Copyright (C) 1991, 93, 96, 97, 98, 99, 2000 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., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +/* Code taken from glibc/sysdeps/sparc/sparc32/ (glibc 2.2.2) */ + +//#include "sysdep.h" +#include <sysdep.h> + +#define _ASM 1 +#define _SETJMP_H +#include <bits/setjmp.h> +#define ENV(base,reg) [%base + (reg * 4)] +#define ST_FLUSH_WINDOWS 3 +#define RW_FP [%fp + 0x48] + +ENTRY(__longjmp) + /* Store our arguments in global registers so we can still + use them while unwinding frames and their register windows. */ + + ld ENV(o0,JB_FP), %g3 /* Cache target FP in register %g3. */ + mov %o0, %g1 /* ENV in %g1 */ + orcc %o1, %g0, %g2 /* VAL in %g2 */ + be,a 0f /* Branch if zero; else skip delay slot. */ + mov 1, %g2 /* Delay slot only hit if zero: VAL = 1. */ +0: + xor %fp, %g3, %o0 + add %fp, 512, %o1 + andncc %o0, 4095, %o0 + bne thread + //bne LOC(thread) + cmp %o1, %g3 + bl thread + //bl LOC(thread) + + /* Now we will loop, unwinding the register windows up the stack + until the restored %fp value matches the target value in %g3. */ + +//LOC(loop): +loop: + cmp %fp, %g3 /* Have we reached the target frame? */ + bl,a loop /* Loop while current fp is below target. */ + //bl,a LOC(loop) /* Loop while current fp is below target. */ + restore /* Unwind register window in delay slot. */ + be,a found /* Better have hit it exactly. */ + //be,a LOC(found) /* Better have hit it exactly. */ + ld ENV(g1,JB_SP), %o0 /* Delay slot: extract target SP. */ + +thread: +//LOC(thread): + /* + * Do a "flush register windows trap". The trap handler in the + * kernel writes all the register windows to their stack slots, and + * marks them all as invalid (needing to be sucked up from the + * stack when used). This ensures that all information needed to + * unwind to these callers is in memory, not in the register + * windows. + */ + ta ST_FLUSH_WINDOWS + ld ENV(g1,JB_PC), %o7 /* Set return PC. */ + ld ENV(g1,JB_SP), %fp /* Set saved SP on restore below. */ + sub %fp, 64, %sp /* Allocate a register frame. */ + st %g3, RW_FP /* Set saved FP on restore below. */ + retl + restore %g2, 0, %o0 /* Restore values from above register frame. */ + +found: +//LOC(found): + /* We have unwound register windows so %fp matches the target. */ + mov %o0, %sp /* OK, install new SP. */ + +//LOC(sp_ok): +sp_ok: + ld ENV(g1,JB_PC), %o0 /* Extract target return PC. */ + jmp %o0 + 8 /* Return there. */ + mov %g2, %o0 /* Delay slot: set return value. */ + +END(__longjmp) |