diff options
Diffstat (limited to 'libc/sysdeps/linux/nios/__longjmp.S')
-rw-r--r-- | libc/sysdeps/linux/nios/__longjmp.S | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/nios/__longjmp.S b/libc/sysdeps/linux/nios/__longjmp.S new file mode 100644 index 000000000..c2b1979cc --- /dev/null +++ b/libc/sysdeps/linux/nios/__longjmp.S @@ -0,0 +1,108 @@ +/* Copyright (C) 1997, 1998 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. */ + +#define _ASM +#define _SETJMP_H +#include <bits/setjmp.h> + + +;---------------------------------------- +; Name: __longjmp +; Description: Restore the current context +; as saved by a previous nr_setjmp +; Input: %o0: jmp_buf (ptr to) array to restore context from +; %o1: integer to return +; Output: %o0 = 0 the first time we're called, or +; whatever longjmp returns later +; Side Effects: uses %g0, %g1 & %g2 +; CWP Depth: 0 +; + + .align 2 + .global __longjmp +__longjmp: + ; + ; The way we'll do this is by executing + ; RESTORE instructions until the old + ; return address matches. Then we'll + ; jump to where setjmp was called from. + ; + ; Since we're moving the window pointer + ; all over the place, we'll naturally + ; only use the %g registers. + ; + + mov %g0,%o0 ; %g0 -> jmp_buf + mov %g1,%o1 ; %g1 = return value + pfx jmpbuf_callersret + ld %g2,[%g0] ; %g2 = old return address +__longjmp_loop: + cmp %g2,%i7 ; Are we there yet? + skps cc_ne + br __longjmp_done + nop ; (delay slot) + + br __longjmp_loop + restore ; (delay slot) + ; + ; One might put in a watchdog counter here, to + ; prevent a runaway stack crawl... but what would that + ; accomplish? What error can we throw? To whom? + ; + +__longjmp_done: + pfx jmpbuf_l0 ; Restore local register l0 + ld %l0,[%g0] + pfx jmpbuf_l1 ; Restore local register l1 + ld %l1,[%g0] + pfx jmpbuf_l2 ; Restore local register l2 + ld %l2,[%g0] + pfx jmpbuf_l3 ; Restore local register l3 + ld %l3,[%g0] + pfx jmpbuf_l4 ; Restore local register l4 + ld %l4,[%g0] + pfx jmpbuf_l5 ; Restore local register l5 + ld %l5,[%g0] + pfx jmpbuf_l6 ; Restore local register l6 + ld %l6,[%g0] + pfx jmpbuf_l7 ; Restore local register l7 + ld %l7,[%g0] + pfx jmpbuf_i0 ; Restore input register i0 + ld %i0,[%g0] + pfx jmpbuf_i1 ; Restore input register i1 + ld %i1,[%g0] + pfx jmpbuf_i2 ; Restore input register i2 + ld %i2,[%g0] + pfx jmpbuf_i3 ; Restore input register i3 + ld %i3,[%g0] + pfx jmpbuf_i4 ; Restore input register i4 + ld %i4,[%g0] + pfx jmpbuf_i5 ; Restore input register i5 + ld %i5,[%g0] + pfx jmpbuf_jmpret + ld %o7,[%g0] ; set fake return address + jmp %o7 ; and kinda return there. + mov %o0,%g1 ; (delay slot) return value + + + + + + + + |