gcc/conditions.h

   1 /* Definitions for condition code handling in final.cc and output routines.
   2    Copyright (C) 1987-2023 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify it under
   7 the terms of the GNU General Public License as published by the Free
   8 Software Foundation; either version 3, or (at your option) any later
   9 version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef GCC_CONDITIONS_H
  21 #define GCC_CONDITIONS_H
  22
  23 /* These are the machine-independent flags:  */
  24
  25 /* Set if the sign of the cc value is inverted:
  26    output a following jump-if-less as a jump-if-greater, etc.  */
  27 #define CC_REVERSED 1
  28
  29 /* This bit means that the current setting of the N bit is bogus
  30    and conditional jumps should use the Z bit in its place.
  31    This state obtains when an extraction of a signed single-bit field
  32    or an arithmetic shift right of a byte by 7 bits
  33    is turned into a btst, because btst does not set the N bit.  */
  34 #define CC_NOT_POSITIVE 2
  35
  36 /* This bit means that the current setting of the N bit is bogus
  37    and conditional jumps should pretend that the N bit is clear.
  38    Used after extraction of an unsigned bit
  39    or logical shift right of a byte by 7 bits is turned into a btst.
  40    The btst does not alter the N bit, but the result of that shift
  41    or extract is never negative.  */
  42 #define CC_NOT_NEGATIVE 4
  43
  44 /* This bit means that the current setting of the overflow flag
  45    is bogus and conditional jumps should pretend there is no overflow.  */
  46 /* ??? Note that for most targets this macro is misnamed as it applies
  47    to the carry flag, not the overflow flag.  */
  48 #define CC_NO_OVERFLOW 010
  49
  50 /* This bit means that what ought to be in the Z bit
  51    should be tested as the complement of the N bit.  */
  52 #define CC_Z_IN_NOT_N 020
  53
  54 /* This bit means that what ought to be in the Z bit
  55    should be tested as the N bit.  */
  56 #define CC_Z_IN_N 040
  57
  58 /* Nonzero if we must invert the sense of the following branch, i.e.
  59    change EQ to NE.  This is not safe for IEEE floating point operations!
  60    It is intended for use only when a combination of arithmetic
  61    or logical insns can leave the condition codes set in a fortuitous
  62    (though inverted) state.  */
  63 #define CC_INVERTED 0100
  64
  65 /* Nonzero if we must convert signed condition operators to unsigned.
  66    This is only used by machine description files.  */
  67 #define CC_NOT_SIGNED 0200
  68
  69 #endif /* GCC_CONDITIONS_H */