sysdeps/alpha/bits/setjmp.h

   1 /* Define the machine-dependent type `jmp_buf'.  Alpha version.
   2    Copyright (C) 1992, 1997 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 Library General Public License as
   7    published by the Free Software Foundation; either version 2 of the
   8    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    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 #ifndef _SETJMP_H
  21 # error "Never include <bits/setjmp.h> directly; use <setjmp.h> instead."
  22 #endif
  23
  24 /* The previous bits/setjmp.h had __jmp_buf defined as a structure.
  25    We use an array of 'long int' instead, to make writing the
  26    assembler easier. Naturally, user code should not depend on
  27    either representation. */
  28
  29 /*
  30  * Integer registers:
  31  *    $0 is the return value (va);
  32  *    $1-$8, $22-$25, $28 are call-used (t0-t7, t8-t11, at);
  33  *    $9-$14 we save here (s0-s5);
  34  *    $15 is the FP and we save it here (fp or s6);
  35  *    $16-$21 are input arguments (call-used) (a0-a5);
  36  *    $26 is the return PC and we save it here (ra);
  37  *    $27 is the procedure value (i.e., the address of __setjmp) (pv or t12);
  38  *    $29 is the global pointer, which the caller will reconstruct
  39  *        from the return address restored in $26 (gp);
  40  *    $30 is the stack pointer and we save it here (sp);
  41  *    $31 is always zero (zero).
  42  *
  43  * Floating-point registers:
  44  *    $f0 is the floating return value;
  45  *    $f1, $f10-$f15, $f22-$f30 are call-used;
  46  *    $f2-$f9 we save here;
  47  *    $f16-$21 are input args (call-used);
  48  *    $f31 is always zero.
  49  *
  50  * Note that even on Alpha hardware that does not have an FPU (there
  51  * isn't such a thing currently) it is required to implement the FP
  52  * registers.
  53  */
  54
  55 #if defined __USE_MISC || defined __ASSEMBLY__
  56 # define JB_S0  0
  57 # define JB_S1  1
  58 # define JB_S2  2
  59 # define JB_S3  3
  60 # define JB_S4  4
  61 # define JB_S5  5
  62 # define JB_PC  6
  63 # define JB_FP  7
  64 # define JB_SP  8
  65 # define JB_F2  9
  66 # define JB_F3  10
  67 # define JB_F4  11
  68 # define JB_F5  12
  69 # define JB_F6  13
  70 # define JB_F7  14
  71 # define JB_F8  15
  72 # define JB_F9  16
  73 #endif
  74
  75 #ifndef __ASSEMBLY__
  76 typedef long int __jmp_buf[17];
  77
  78 /* Test if longjmp to JMPBUF would unwind the frame containing a local
  79    variable at ADDRESS.  */
  80 #define _JMPBUF_UNWINDS(_jmpbuf, _address)                              \
  81   ({ register void *_sp __asm__("$30"); void *_addr = (_address);       \
  82      _sp <= _addr && _addr < (void *)((_jmpbuf)[JB_SP]); })
  83 #endif