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/* Bounded-pointer definitions for PowerPC assembler.
Copyright (C) 2000 Free Software Foundation, Inc.
Contributed by Greg McGary <greg@mcgary.org>
This file is part of the GNU C Library. Its master source is NOT part of
the C library, however. The master source lives in the GNU MP Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#if __BOUNDED_POINTERS__
/* Byte offsets of BP components. */
# define oVALUE 0
# define oLOW 4
# define oHIGH 8
/* Don't check bounds, just convert the BP register to its simple
pointer value. */
# define DISCARD_BOUNDS(rBP) \
lwz rBP, oVALUE(rBP)
/* Check low bound, with the side effect that the BP register is converted
its simple pointer value. Move the high bound into a register for
later use. */
# define CHECK_BOUNDS_LOW(rBP, rLOW, rHIGH) \
lwz rHIGH, oHIGH(rBP); \
lwz rLOW, oLOW(rBP); \
lwz rBP, oVALUE(rBP); \
twllt rBP, rLOW
/* Check the high bound, which is in a register, using the given
conditional trap instruction. */
# define CHECK_BOUNDS_HIGH(rVALUE, rHIGH, TWLcc) \
TWLcc rVALUE, rHIGH
/* Check the high bound, which is stored at the return-value's high
bound slot, using the given conditional trap instruction. */
# define CHECK_BOUNDS_HIGH_RTN(rVALUE, rHIGH, TWLcc) \
lwz rHIGH, oHIGH(rRTN); \
TWLcc rVALUE, rHIGH
/* Check both bounds, with the side effect that the BP register is
converted to its simple pointer value. */
# define CHECK_BOUNDS_BOTH(rBP, rLOW, rHIGH) \
CHECK_BOUNDS_LOW(rBP, rLOW, rHIGH); \
twlge rBP, rHIGH
/* Check bounds on a memory region of given length, with the side
effect that the BP register is converted to its simple pointer
value. */
# define CHECK_BOUNDS_BOTH_WIDE(rBP, rLOW, rHIGH, rLENGTH) \
CHECK_BOUNDS_LOW (rBP, rLOW, rHIGH); \
sub rHIGH, rHIGH, rLENGTH; \
twlgt rBP, rHIGH
# define CHECK_BOUNDS_BOTH_WIDE_LIT(rBP, rLOW, rHIGH, LENGTH) \
CHECK_BOUNDS_LOW (rBP, rLOW, rHIGH); \
subi rHIGH, rHIGH, LENGTH; \
twlgt rBP, rHIGH
/* Store a pointer value register into the return-value's pointer
value slot. */
# define STORE_RETURN_VALUE(rVALUE) \
stw rVALUE, oVALUE(rRTN)
/* Store a low and high bounds into the return-value's pointer bounds
slots. */
# define STORE_RETURN_BOUNDS(rLOW, rHIGH) \
stw rLOW, oLOW(rRTN); \
stw rHIGH, oHIGH(rRTN)
/* Stuff zero value/low/high into the BP addressed by rRTN. */
# define RETURN_NULL_BOUNDED_POINTER \
li r4, 0; \
STORE_RETURN_VALUE (r4); \
STORE_RETURN_BOUNDS (r4, r4)
#else
# define DISCARD_BOUNDS(rBP)
# define CHECK_BOUNDS_LOW(rBP, rLOW, rHIGH)
# define CHECK_BOUNDS_HIGH(rVALUE, rHIGH, TWLcc)
# define CHECK_BOUNDS_HIGH_RTN(rVALUE, rHIGH, TWLcc)
# define CHECK_BOUNDS_BOTH(rBP, rLOW, rHIGH)
# define CHECK_BOUNDS_BOTH_WIDE(rBP, rLOW, rHIGH, rLENGTH)
# define CHECK_BOUNDS_BOTH_WIDE_LIT(rBP, rLOW, rHIGH, LENGTH)
# define STORE_RETURN_VALUE(rVALUE)
# define STORE_RETURN_BOUNDS(rLOW, rHIGH)
# define RETURN_NULL_BOUNDED_POINTER li rRTN, 0
#endif
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