sysdeps/alpha/bits/setjmp.h

   1 /* Define the machine-dependent type `jmp_buf'.  Alpha version.
   2    Copyright (C) 1992,1997,2003,2005,2006 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #ifndef _BITS_SETJMP_H
  21 #define _BITS_SETJMP_H  1
  22
  23 #if !defined _SETJMP_H && !defined _PTHREAD_H
  24 # error "Never include <bits/setjmp.h> directly; use <setjmp.h> instead."
  25 #endif
  26
  27 /* The previous bits/setjmp.h had __jmp_buf defined as a structure.
  28    We use an array of 'long int' instead, to make writing the
  29    assembler easier. Naturally, user code should not depend on
  30    either representation. */
  31
  32 /*
  33  * Integer registers:
  34  *    $0 is the return value (va);
  35  *    $1-$8, $22-$25, $28 are call-used (t0-t7, t8-t11, at);
  36  *    $9-$14 we save here (s0-s5);
  37  *    $15 is the FP and we save it here (fp or s6);
  38  *    $16-$21 are input arguments (call-used) (a0-a5);
  39  *    $26 is the return PC and we save it here (ra);
  40  *    $27 is the procedure value (i.e., the address of __setjmp) (pv or t12);
  41  *    $29 is the global pointer, which the caller will reconstruct
  42  *        from the return address restored in $26 (gp);
  43  *    $30 is the stack pointer and we save it here (sp);
  44  *    $31 is always zero (zero).
  45  *
  46  * Floating-point registers:
  47  *    $f0 is the floating return value;
  48  *    $f1, $f10-$f15, $f22-$f30 are call-used;
  49  *    $f2-$f9 we save here;
  50  *    $f16-$21 are input args (call-used);
  51  *    $f31 is always zero.
  52  *
  53  * Note that even on Alpha hardware that does not have an FPU (there
  54  * isn't such a thing currently) it is required to implement the FP
  55  * registers.
  56  */
  57
  58 #ifndef __ASSEMBLY__
  59 typedef long int __jmp_buf[17];
  60 #endif
  61
  62 #endif  /* bits/setjmp.h */