sysdeps/powerpc/powerpc64/bp-asm.h

   1 /* Bounded-pointer definitions for PowerPC64 assembler.
   2    Copyright (C) 2000, 2002 Free Software Foundation, Inc.
   3    Contributed by Greg McGary <greg@mcgary.org>
   4
   5    This file is part of the GNU C Library.  Its master source is NOT part of
   6    the C library, however.  The master source lives in the GNU MP Library.
   7
   8    The GNU C Library is free software; you can redistribute it and/or
   9    modify it under the terms of the GNU Library General Public License as
  10    published by the Free Software Foundation; either version 2 of the
  11    License, or (at your option) any later version.
  12
  13    The GNU C Library is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16    Library General Public License for more details.
  17
  18    You should have received a copy of the GNU Library General Public
  19    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  20    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  21    Boston, MA 02111-1307, USA.  */
  22
  23 #if __BOUNDED_POINTERS__
  24
  25 /* Byte offsets of BP components.  */
  26 # define oVALUE 0
  27 # define oLOW   4
  28 # define oHIGH  8
  29
  30 /* Don't check bounds, just convert the BP register to its simple
  31    pointer value.  */
  32
  33 # define DISCARD_BOUNDS(rBP)                    \
  34         ld      rBP, oVALUE(rBP)
  35
  36 /* Check low bound, with the side effect that the BP register is converted
  37    its simple pointer value.  Move the high bound into a register for
  38    later use.  */
  39
  40 # define CHECK_BOUNDS_LOW(rBP, rLOW, rHIGH)     \
  41         ld      rHIGH, oHIGH(rBP);              \
  42         ld      rLOW, oLOW(rBP);                \
  43         ld      rBP, oVALUE(rBP);               \
  44         tdllt   rBP, rLOW
  45
  46 /* Check the high bound, which is in a register, using the given
  47    conditional trap instruction.  */
  48
  49 # define CHECK_BOUNDS_HIGH(rVALUE, rHIGH, TWLcc) \
  50         TWLcc   rVALUE, rHIGH
  51
  52 /* Check the high bound, which is stored at the return-value's high
  53    bound slot, using the given conditional trap instruction.  */
  54
  55 # define CHECK_BOUNDS_HIGH_RTN(rVALUE, rHIGH, TWLcc)    \
  56         ld      rHIGH, oHIGH(rRTN);                     \
  57         TWLcc   rVALUE, rHIGH
  58
  59 /* Check both bounds, with the side effect that the BP register is
  60    converted to its simple pointer value.  */
  61
  62 # define CHECK_BOUNDS_BOTH(rBP, rLOW, rHIGH)    \
  63         CHECK_BOUNDS_LOW(rBP, rLOW, rHIGH);     \
  64         tdlge   rBP, rHIGH
  65
  66 /* Check bounds on a memory region of given length, with the side
  67    effect that the BP register is converted to its simple pointer
  68    value.  */
  69
  70 # define CHECK_BOUNDS_BOTH_WIDE(rBP, rLOW, rHIGH, rLENGTH)      \
  71         CHECK_BOUNDS_LOW (rBP, rLOW, rHIGH);                    \
  72         sub     rHIGH, rHIGH, rLENGTH;                          \
  73         tdlgt   rBP, rHIGH
  74
  75 # define CHECK_BOUNDS_BOTH_WIDE_LIT(rBP, rLOW, rHIGH, LENGTH)   \
  76         CHECK_BOUNDS_LOW (rBP, rLOW, rHIGH);                    \
  77         subi    rHIGH, rHIGH, LENGTH;                           \
  78         tdlgt   rBP, rHIGH
  79
  80 /* Store a pointer value register into the return-value's pointer
  81    value slot.  */
  82
  83 # define STORE_RETURN_VALUE(rVALUE)             \
  84         std     rVALUE, oVALUE(rRTN)
  85
  86 /* Store a low and high bounds into the return-value's pointer bounds
  87    slots.  */
  88
  89 # define STORE_RETURN_BOUNDS(rLOW, rHIGH)       \
  90         std     rLOW, oLOW(rRTN);               \
  91         std     rHIGH, oHIGH(rRTN)
  92
  93 /* Stuff zero value/low/high into the BP addressed by rRTN.  */
  94
  95 # define RETURN_NULL_BOUNDED_POINTER            \
  96         li      r4, 0;                          \
  97         STORE_RETURN_VALUE (r4);                \
  98         STORE_RETURN_BOUNDS (r4, r4)
  99
 100 #else
 101
 102 # define DISCARD_BOUNDS(rBP)
 103 # define CHECK_BOUNDS_LOW(rBP, rLOW, rHIGH)
 104 # define CHECK_BOUNDS_HIGH(rVALUE, rHIGH, TWLcc)
 105 # define CHECK_BOUNDS_HIGH_RTN(rVALUE, rHIGH, TWLcc)
 106 # define CHECK_BOUNDS_BOTH(rBP, rLOW, rHIGH)
 107 # define CHECK_BOUNDS_BOTH_WIDE(rBP, rLOW, rHIGH, rLENGTH)
 108 # define CHECK_BOUNDS_BOTH_WIDE_LIT(rBP, rLOW, rHIGH, LENGTH)
 109 # define STORE_RETURN_VALUE(rVALUE)
 110 # define STORE_RETURN_BOUNDS(rLOW, rHIGH)
 111
 112 # define RETURN_NULL_BOUNDED_POINTER li rRTN, 0
 113
 114 #endif
 115