gcc/real.h

   1 /* Front-end tree definitions for GNU compiler.
   2    Copyright (C) 1989, 1991 Free Software Foundation, Inc.
   3
   4 This file is part of GNU CC.
   5
   6 GNU CC is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU CC is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU CC; see the file COPYING.  If not, write to
  18 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
  19
  20 #ifndef REAL_H_INCLUDED
  21 #define REAL_H_INCLUDED
  22
  23 /* Define codes for all the float formats that we know of.  */
  24 #define UNKNOWN_FLOAT_FORMAT 0
  25 #define IEEE_FLOAT_FORMAT 1
  26 #define VAX_FLOAT_FORMAT 2
  27
  28 /* Default to IEEE float if not specified.  Nearly all machines use it.  */
  29
  30 #ifndef TARGET_FLOAT_FORMAT
  31 #define TARGET_FLOAT_FORMAT     IEEE_FLOAT_FORMAT
  32 #endif
  33
  34 #ifndef HOST_FLOAT_FORMAT
  35 #define HOST_FLOAT_FORMAT       IEEE_FLOAT_FORMAT
  36 #endif
  37
  38 #if TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
  39 #define REAL_INFINITY
  40 #endif
  41
  42 #ifdef REAL_ARITHMETIC
  43 /* Defining REAL_IS_NOT_DOUBLE breaks certain initializations
  44    when REAL_ARITHMETIC etc. are not defined.  */
  45
  46 /* Now see if the host and target machines use the same format.
  47    If not, define REAL_IS_NOT_DOUBLE (even if we end up representing
  48    reals as doubles because we have no better way in this cross compiler.)
  49    This turns off various optimizations that can happen when we know the
  50    compiler's float format matches the target's float format.
  51    */
  52 #if HOST_FLOAT_FORMAT != TARGET_FLOAT_FORMAT
  53 #define REAL_IS_NOT_DOUBLE
  54 #ifndef REAL_VALUE_TYPE
  55 #define REAL_VALUE_TYPE \
  56   struct real_value { long i[sizeof (double) / sizeof (long)]; }
  57 #endif /* no REAL_VALUE_TYPE */
  58 #endif /* formats differ */
  59 #endif /* 0 */
  60
  61 /* If we are not cross-compiling, use a `double' to represent the
  62    floating-point value.  Otherwise, use some other type
  63    (probably a struct containing an array of longs).  */
  64 #ifndef REAL_VALUE_TYPE
  65 #define REAL_VALUE_TYPE double
  66 #else
  67 #define REAL_IS_NOT_DOUBLE
  68 #endif
  69
  70 /* Compare two floating-point values for equality.  */
  71 #ifndef REAL_VALUES_EQUAL
  72 #define REAL_VALUES_EQUAL(x,y) ((x) == (y))
  73 #endif
  74
  75 /* Compare two floating-point values for less than.  */
  76 #ifndef REAL_VALUES_LESS
  77 #define REAL_VALUES_LESS(x,y) ((x) < (y))
  78 #endif
  79
  80 /* Convert a floating-point value to integer by truncating.  */
  81 #ifndef REAL_VALUE_FIX_TRUNCATE
  82 #define REAL_VALUE_FIX_TRUNCATE(x) ((int) (x))
  83 #endif
  84
  85 /* Convert a floating-point value to unsigned integer by truncating.  */
  86 #ifndef REAL_VALUE_UNSIGNED_FIX_TRUNCATE
  87 #define REAL_VALUE_UNSIGNED_FIX_TRUNCATE(x) ((unsigned int) (x))
  88 #endif
  89
  90 /* Convert a floating-point value to integer, using any rounding mode.  */
  91 #ifndef REAL_VALUE_FIX
  92 #define REAL_VALUE_FIX(x) ((int) (x))
  93 #endif
  94
  95 /* Convert a floating-point value to unsigned integer, using any rounding
  96    mode.  */
  97 #ifndef REAL_VALUE_UNSIGNED_FIX
  98 #define REAL_VALUE_UNSIGNED_FIX(x) ((unsigned int) (x))
  99 #endif
 100
 101 /* Scale X by Y powers of 2.  */
 102 #ifndef REAL_VALUE_LDEXP
 103 #define REAL_VALUE_LDEXP(x,y) ldexp (x, y)
 104 extern double ldexp ();
 105 #endif
 106
 107 /* Convert the string X to a floating-point value.  */
 108 #ifndef REAL_VALUE_ATOF
 109 #define REAL_VALUE_ATOF(x) atof (x)
 110 #if defined (MIPSEL) || defined (MIPSEB)
 111 /* MIPS compiler can't handle parens around the function name.
 112    This problem *does not* appear to be connected with any
 113    macro definition for atof.  It does not seem there is one.  */
 114 extern double atof ();
 115 #else
 116 extern double (atof) ();
 117 #endif
 118 #endif
 119
 120 /* Negate the floating-point value X.  */
 121 #ifndef REAL_VALUE_NEGATE
 122 #define REAL_VALUE_NEGATE(x) (- (x))
 123 #endif
 124
 125 /* Truncate the floating-point value X to mode MODE.  This is correct only
 126    for the most common case where the host and target have objects of the same
 127    size and where `float' is SFmode.  */
 128
 129 #ifndef REAL_VALUE_TRUNCATE
 130 #define REAL_VALUE_TRUNCATE(mode, x) \
 131  (GET_MODE_BITSIZE (mode) == GET_MODE_BITSIZE (SFmode) ? (float) (x) : (x))
 132 #endif
 133
 134 /* Determine whether a floating-point value X is infinite. */
 135 #ifndef REAL_VALUE_ISINF
 136 #define REAL_VALUE_ISINF(x) (target_isinf (x))
 137 #endif
 138
 139 /* Determine whether a floating-point value X is minus 0. */
 140 #ifndef REAL_VALUE_MINUS_ZERO
 141 #define REAL_VALUE_MINUS_ZERO(x) (target_minus_zero (x))
 142 #endif
 143 \f
 144 /* Constant real values 0, 1, 2, and -1.  */
 145
 146 extern REAL_VALUE_TYPE dconst0;
 147 extern REAL_VALUE_TYPE dconst1;
 148 extern REAL_VALUE_TYPE dconst2;
 149 extern REAL_VALUE_TYPE dconstm1;
 150
 151 /* Union type used for extracting real values from CONST_DOUBLEs
 152    or putting them in.  */
 153
 154 union real_extract
 155 {
 156   REAL_VALUE_TYPE d;
 157   int i[sizeof (REAL_VALUE_TYPE) / sizeof (int)];
 158 };
 159
 160 /* For a CONST_DOUBLE:
 161    The usual two ints that hold the value.
 162    For a DImode, that is all there are;
 163     and CONST_DOUBLE_LOW is the low-order word and ..._HIGH the high-order.
 164    For a float, the number of ints varies,
 165     and CONST_DOUBLE_LOW is the one that should come first *in memory*.
 166     So use &CONST_DOUBLE_LOW(r) as the address of an array of ints.  */
 167 #define CONST_DOUBLE_LOW(r) XINT (r, 2)
 168 #define CONST_DOUBLE_HIGH(r) XINT (r, 3)
 169
 170 /* Link for chain of all CONST_DOUBLEs in use in current function.  */
 171 #define CONST_DOUBLE_CHAIN(r) XEXP (r, 1)
 172 /* The MEM which represents this CONST_DOUBLE's value in memory,
 173    or const0_rtx if no MEM has been made for it yet,
 174    or cc0_rtx if it is not on the chain.  */
 175 #define CONST_DOUBLE_MEM(r) XEXP (r, 0)
 176
 177 /* Function to return a real value (not a tree node)
 178    from a given integer constant.  */
 179 REAL_VALUE_TYPE real_value_from_int_cst ();
 180
 181 /* Given a CONST_DOUBLE in FROM, store into TO the value it represents.  */
 182
 183 #define REAL_VALUE_FROM_CONST_DOUBLE(to, from)          \
 184 do { union real_extract u;                              \
 185      bcopy (&CONST_DOUBLE_LOW ((from)), &u, sizeof u);  \
 186      to = u.d; } while (0)
 187
 188 /* Return a CONST_DOUBLE with value R and mode M.  */
 189
 190 #define CONST_DOUBLE_FROM_REAL_VALUE(r,m) immed_real_const_1 (r, m)
 191
 192 #endif /* Not REAL_H_INCLUDED */