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glibc  2.9
setjmp.h
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00001 /* Define the machine-dependent type `jmp_buf'.  Alpha version.
00002    Copyright (C) 1992,1997,2003,2005,2006 Free Software Foundation, Inc.
00003    This file is part of the GNU C Library.
00004 
00005    The GNU C Library is free software; you can redistribute it and/or
00006    modify it under the terms of the GNU Lesser General Public
00007    License as published by the Free Software Foundation; either
00008    version 2.1 of the License, or (at your option) any later version.
00009 
00010    The GNU C Library is distributed in the hope that it will be useful,
00011    but WITHOUT ANY WARRANTY; without even the implied warranty of
00012    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00013    Lesser General Public License for more details.
00014 
00015    You should have received a copy of the GNU Lesser General Public
00016    License along with the GNU C Library; if not, write to the Free
00017    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
00018    02111-1307 USA.  */
00019 
00020 #ifndef _BITS_SETJMP_H
00021 #define _BITS_SETJMP_H  1
00022 
00023 #if !defined _SETJMP_H && !defined _PTHREAD_H
00024 # error "Never include <bits/setjmp.h> directly; use <setjmp.h> instead."
00025 #endif
00026 
00027 /* The previous bits/setjmp.h had __jmp_buf defined as a structure.
00028    We use an array of 'long int' instead, to make writing the
00029    assembler easier. Naturally, user code should not depend on
00030    either representation. */
00031 
00032 /*
00033  * Integer registers:
00034  *    $0 is the return value (va);
00035  *    $1-$8, $22-$25, $28 are call-used (t0-t7, t8-t11, at);
00036  *    $9-$14 we save here (s0-s5);
00037  *    $15 is the FP and we save it here (fp or s6);
00038  *    $16-$21 are input arguments (call-used) (a0-a5);
00039  *    $26 is the return PC and we save it here (ra);
00040  *    $27 is the procedure value (i.e., the address of __setjmp) (pv or t12);
00041  *    $29 is the global pointer, which the caller will reconstruct
00042  *        from the return address restored in $26 (gp);
00043  *    $30 is the stack pointer and we save it here (sp);
00044  *    $31 is always zero (zero).
00045  *
00046  * Floating-point registers:
00047  *    $f0 is the floating return value;
00048  *    $f1, $f10-$f15, $f22-$f30 are call-used;
00049  *    $f2-$f9 we save here;
00050  *    $f16-$21 are input args (call-used);
00051  *    $f31 is always zero.
00052  *
00053  * Note that even on Alpha hardware that does not have an FPU (there
00054  * isn't such a thing currently) it is required to implement the FP
00055  * registers.
00056  */
00057 
00058 #ifndef __ASSEMBLY__
00059 typedef long int __jmp_buf[17];
00060 #endif
00061 
00062 #endif  /* bits/setjmp.h */