sysdeps/tile/stackinfo.h

   1 /* Copyright (C) 2011-2017 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Chris Metcalf <cmetcalf@tilera.com>, 2011.
   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, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 /* This file contains a bit of information about the stack allocation
  20    of the processor.  */
  21
  22 #ifndef _STACKINFO_H
  23 #define _STACKINFO_H    1
  24
  25 #include <elf.h>
  26
  27 /* On tile the stack grows down.  */
  28 #define _STACK_GROWS_DOWN       1
  29
  30 /* Default to a non-executable stack. */
  31 #define DEFAULT_STACK_PERMS (PF_R|PF_W)
  32
  33 /* Access to the stack pointer.  The macros are used in alloca_account
  34    for which they need to act as barriers as well, hence the additional
  35    (unnecessary) parameters.  */
  36 #define stackinfo_get_sp() \
  37   ({ void *p__; asm volatile ("move %0, sp" : "=r" (p__)); p__; })
  38 #if defined __tilegx__ && __WORDSIZE == 32
  39 #define __stackinfo_sub "subx"
  40 #else
  41 #define __stackinfo_sub "sub"
  42 #endif
  43 #define stackinfo_sub_sp(ptr)                                  \
  44   ({ ptrdiff_t d__;                                             \
  45     asm volatile (__stackinfo_sub " %0, %0, sp" : "=r" (d__) : "0" (ptr));  \
  46     d__; })
  47
  48 #endif /* stackinfo.h */