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[/] [openrisc/] [trunk/] [gnu-old/] [gcc-4.2.2/] [gcc/] [conditions.h] - Blame information for rev 841

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/* Definitions for condition code handling in final.c and output routines.
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   Copyright (C) 1987, 2007 Free Software Foundation, Inc.
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This file is part of GCC.
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GCC is free software; you can redistribute it and/or modify it under
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the terms of the GNU General Public License as published by the Free
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Software Foundation; either version 3, or (at your option) any later
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version.
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GCC is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY; without even the implied warranty of MERCHANTABILITY or
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FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
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for more details.
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You should have received a copy of the GNU General Public License
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along with GCC; see the file COPYING3.  If not see
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<http://www.gnu.org/licenses/>.  */
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/* None of the things in the files exist if we don't use CC0.  */
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#ifdef HAVE_cc0
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/* The variable cc_status says how to interpret the condition code.
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   It is set by output routines for an instruction that sets the cc's
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   and examined by output routines for jump instructions.
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   cc_status contains two components named `value1' and `value2'
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   that record two equivalent expressions for the values that the
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   condition codes were set from.  (Either or both may be null if
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   there is no useful expression to record.)  These fields are
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   used for eliminating redundant test and compare instructions
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   in the cases where the condition codes were already set by the
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   previous instruction.
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   cc_status.flags contains flags which say that the condition codes
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   were set in a nonstandard manner.  The output of jump instructions
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   uses these flags to compensate and produce the standard result
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   with the nonstandard condition codes.  Standard flags are defined here.
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   The tm.h file can also define other machine-dependent flags.
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   cc_status also contains a machine-dependent component `mdep'
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   whose type, `CC_STATUS_MDEP', may be defined as a macro in the
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   tm.h file.  */
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#ifndef CC_STATUS_MDEP
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#define CC_STATUS_MDEP int
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#endif
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#ifndef CC_STATUS_MDEP_INIT
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#define CC_STATUS_MDEP_INIT 0
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#endif
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typedef struct {int flags; rtx value1, value2; CC_STATUS_MDEP mdep;} CC_STATUS;
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/* While outputting an insn as assembler code,
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   this is the status BEFORE that insn.  */
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extern CC_STATUS cc_prev_status;
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/* While outputting an insn as assembler code,
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   this is being altered to the status AFTER that insn.  */
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extern CC_STATUS cc_status;
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/* These are the machine-independent flags:  */
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/* Set if the sign of the cc value is inverted:
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   output a following jump-if-less as a jump-if-greater, etc.  */
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#define CC_REVERSED 1
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/* This bit means that the current setting of the N bit is bogus
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   and conditional jumps should use the Z bit in its place.
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   This state obtains when an extraction of a signed single-bit field
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   or an arithmetic shift right of a byte by 7 bits
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   is turned into a btst, because btst does not set the N bit.  */
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#define CC_NOT_POSITIVE 2
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/* This bit means that the current setting of the N bit is bogus
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   and conditional jumps should pretend that the N bit is clear.
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   Used after extraction of an unsigned bit
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   or logical shift right of a byte by 7 bits is turned into a btst.
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   The btst does not alter the N bit, but the result of that shift
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   or extract is never negative.  */
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#define CC_NOT_NEGATIVE 4
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/* This bit means that the current setting of the overflow flag
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   is bogus and conditional jumps should pretend there is no overflow.  */
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/* ??? Note that for most targets this macro is misnamed as it applies
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   to the carry flag, not the overflow flag.  */
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#define CC_NO_OVERFLOW 010
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/* This bit means that what ought to be in the Z bit
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   should be tested as the complement of the N bit.  */
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#define CC_Z_IN_NOT_N 020
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/* This bit means that what ought to be in the Z bit
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   should be tested as the N bit.  */
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#define CC_Z_IN_N 040
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/* Nonzero if we must invert the sense of the following branch, i.e.
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   change EQ to NE.  This is not safe for IEEE floating point operations!
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   It is intended for use only when a combination of arithmetic
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   or logical insns can leave the condition codes set in a fortuitous
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   (though inverted) state.  */
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#define CC_INVERTED 0100
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/* Nonzero if we must convert signed condition operators to unsigned.
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   This is only used by machine description files.  */
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#define CC_NOT_SIGNED 0200
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/* This is how to initialize the variable cc_status.
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   final does this at appropriate moments.  */
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#define CC_STATUS_INIT  \
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 (cc_status.flags = 0, cc_status.value1 = 0, cc_status.value2 = 0,  \
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  CC_STATUS_MDEP_INIT)
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#endif

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