mach/con_float

   1 /*
   2   (c) copyright 1988 by the Vrije Universiteit, Amsterdam, The Netherlands.
   3   See the copyright notice in the ACK home directory, in the file "Copyright".
   4 */
   5
   6 /* $Id: con_float,v 2.11 1994/06/24 12:53:35 ceriel Exp $ */
   7
   8 /*
   9    #define CODE_GENERATOR for code generator
  10    #define CODE_EXPANDER for code expander
  11
  12    #define IEEEFLOAT for machines using IEEE floating point format
  13    #define PDPFLOAT for machines using the PDP-11 floating point format
  14    If none of these are defined, the format of the machine on which the
  15    code generator runs is used.
  16    Returns 1 if sz has an illegal value, 2 in case of overflow,
  17    and 0 if all went well.
  18    If neither IEEEFLOAT nor PDPFLOAT are defined, the return value is not
  19    trustworthy.
  20
  21    Unfortunately, the IEEE standard does not define the byte-order.
  22    depends on the #defines
  23         FL_MSL_AT_LOW_ADDRESS   1 if most significant long is at low address
  24         FL_MSW_AT_LOW_ADDRESS   1 if most significant word is at low address
  25         FL_MSB_AT_LOW_ADDRESS   1 if most significant byte is at low address
  26 */
  27 #ifdef IEEEFLOAT
  28 #define USE_FLT
  29 #endif
  30 #ifdef PDPFLOAT
  31 #define USE_FLT
  32 #undef FL_MSL_AT_LOW_ADDRESS
  33 #define FL_MSL_AT_LOW_ADDRESS 1
  34 #undef FL_MSW_AT_LOW_ADDRESS
  35 #define FL_MSW_AT_LOW_ADDRESS 1
  36 #undef FL_MSB_AT_LOW_ADDRESS
  37 #define FL_MSB_AT_LOW_ADDRESS 0
  38 #endif
  39
  40 #define I0 ((FL_MSL_AT_LOW_ADDRESS ? 0 : 4) + (FL_MSW_AT_LOW_ADDRESS ? 0 : 2) \
  41                 + (FL_MSB_AT_LOW_ADDRESS ? 0 : 1))
  42 #define I1 ((FL_MSL_AT_LOW_ADDRESS ? 0 : 4) + (FL_MSW_AT_LOW_ADDRESS ? 0 : 2) \
  43                 + (FL_MSB_AT_LOW_ADDRESS ? 1 : 0))
  44 #define I2 ((FL_MSL_AT_LOW_ADDRESS ? 0 : 4) + (FL_MSW_AT_LOW_ADDRESS ? 2 : 0) \
  45                 + (FL_MSB_AT_LOW_ADDRESS ? 0 : 1))
  46 #define I3 ((FL_MSL_AT_LOW_ADDRESS ? 0 : 4) + (FL_MSW_AT_LOW_ADDRESS ? 2 : 0) \
  47                 + (FL_MSB_AT_LOW_ADDRESS ? 1 : 0))
  48 #define I4 ((FL_MSL_AT_LOW_ADDRESS ? 4 : 0) + (FL_MSW_AT_LOW_ADDRESS ? 0 : 2) \
  49                 + (FL_MSB_AT_LOW_ADDRESS ? 0 : 1))
  50 #define I5 ((FL_MSL_AT_LOW_ADDRESS ? 4 : 0) + (FL_MSW_AT_LOW_ADDRESS ? 0 : 2) \
  51                 + (FL_MSB_AT_LOW_ADDRESS ? 1 : 0))
  52 #define I6 ((FL_MSL_AT_LOW_ADDRESS ? 4 : 0) + (FL_MSW_AT_LOW_ADDRESS ? 2 : 0) \
  53                 + (FL_MSB_AT_LOW_ADDRESS ? 0 : 1))
  54 #define I7 ((FL_MSL_AT_LOW_ADDRESS ? 4 : 0) + (FL_MSW_AT_LOW_ADDRESS ? 2 : 0) \
  55                 + (FL_MSB_AT_LOW_ADDRESS ? 1 : 0))
  56
  57 #ifndef USE_FLT
  58 static int
  59 float_cst(str, sz, buf)
  60         char *str, *buf;
  61         int sz;
  62 {
  63         int i;
  64         char *p;
  65         float fl;
  66         double f;
  67         double atof();
  68
  69         if (sz!= 4 && sz!= 8)   {
  70                 return 1;
  71         }
  72         f = atof(str);
  73         if (sz == 4) {
  74                 fl = f;
  75                 p = (char *) &fl;
  76         }
  77         else {
  78                 p = (char *) &f;
  79         }
  80         for (i = sz; i; i--) {
  81                 *buf++ = *p++;
  82         }
  83         return 0;
  84 }
  85 #else /* USE_FLT */
  86
  87 #include <ctype.h>
  88 #include <flt_arith.h>
  89
  90 int
  91 float_cst(str, sz, buf)
  92         char *str, *buf;
  93         int sz;
  94 {
  95         int overflow = 0;
  96         flt_arith e;
  97
  98         if (sz!= 4 && sz!= 8)   {
  99                 return 1;
 100         }
 101         flt_str2flt(str, &e);
 102 #ifdef IEEEFLOAT
 103         if (sz == 4) {
 104 #endif
 105 #ifdef PDPFLOAT
 106                 e.flt_exp += 129;
 107 #else
 108                 e.flt_exp += 127;
 109 #endif
 110                 if (e.flt_mantissa.flt_h_32 == 0) e.flt_exp = 0;
 111 #ifdef IEEEFLOAT
 112                 if (e.flt_mantissa.flt_h_32 & 0x80) {
 113                         /* rounding */
 114                         if ((e.flt_mantissa.flt_h_32 & 0xffffff00) == 0xffffff00) {
 115                                 e.flt_exp++;
 116                                 e.flt_mantissa.flt_h_32 = 0x80000000;
 117                         }
 118                         else {
 119                                 e.flt_mantissa.flt_h_32 += 0x80;
 120                         }
 121                 }
 122                 if (e.flt_exp >= 255) {
 123                         overflow = 1;
 124                         e.flt_exp = 255;
 125                         e.flt_mantissa.flt_h_32 = e.flt_mantissa.flt_l_32 = 0;
 126                 }
 127                 if (e.flt_exp <= 0) {
 128                         flt_b64_sft(&(e.flt_mantissa), 1);
 129                         if (e.flt_exp < 0) {
 130                                 flt_b64_sft(&(e.flt_mantissa), -e.flt_exp);
 131                                 e.flt_exp = 0;
 132                         }
 133                 }
 134 #endif
 135 #ifndef IEEEFLOAT
 136                 if (sz == 4 && (e.flt_mantissa.flt_h_32 & 0x80)) {
 137                         /* rounding */
 138                         if ((e.flt_mantissa.flt_h_32 & 0xffffff00) == 0xffffff00) {
 139                                 e.flt_exp++;
 140                                 e.flt_mantissa.flt_h_32 = 0x80000000;
 141                         }
 142                         else {
 143                                 e.flt_mantissa.flt_h_32 += 0x80;
 144                         }
 145                 }
 146                 if (sz == 8 && (e.flt_mantissa.flt_l_32 & 0x80)) {
 147                         /* rounding */
 148                         if ((e.flt_mantissa.flt_l_32 & 0xffffff00) == 0xffffff00) {
 149                                 e.flt_mantissa.flt_l_32 = 0;
 150                                 if (e.flt_mantissa.flt_h_32 == 0xffffffff) {
 151                                         e.flt_exp++;
 152                                         e.flt_mantissa.flt_h_32 = 0x80000000;
 153                                 }
 154                                 else e.flt_mantissa.flt_h_32++;
 155                         }
 156                         else {
 157                                 e.flt_mantissa.flt_l_32 += 0x80;
 158                         }
 159                 }
 160                 if (e.flt_exp > 255) {
 161                         overflow = 1;
 162                         e.flt_exp = 255;
 163                         e.flt_mantissa.flt_h_32 = e.flt_mantissa.flt_l_32 = 0xffffffff;
 164                 }
 165 #endif
 166                 buf[I0] = (e.flt_sign << 7) | (e.flt_exp >> 1);
 167                 buf[I1] = ((e.flt_exp&1) << 7) |
 168                                 ((e.flt_mantissa.flt_h_32 & 0x7fffffff) >> 24);
 169                 buf[I2] = e.flt_mantissa.flt_h_32 >> 16;
 170                 buf[I3] = e.flt_mantissa.flt_h_32 >> 8;
 171 #ifndef IEEEFLOAT
 172                 if (sz == 8) {
 173                         buf[I4] = e.flt_mantissa.flt_h_32;
 174                         buf[I5] = e.flt_mantissa.flt_l_32 >> 24;
 175                         buf[I6] = e.flt_mantissa.flt_l_32 >> 16;
 176                         buf[I7] = e.flt_mantissa.flt_l_32 >> 8;
 177                         flt_b64_sft(&(e.flt_mantissa), -56);
 178                 }
 179                 else
 180 #endif
 181                         flt_b64_sft(&(e.flt_mantissa), -24);
 182 #ifdef IEEEFLOAT
 183         }
 184         else {
 185                 e.flt_exp += 1023;
 186                 if (e.flt_mantissa.flt_h_32 == 0) e.flt_exp = 0;
 187                 if (e.flt_mantissa.flt_l_32 & 0x400) {
 188                         /* rounding */
 189                         if ((e.flt_mantissa.flt_l_32 & 0xfffff800) == 0xfffff800) {
 190                                 e.flt_mantissa.flt_l_32 = 0;
 191                                 if (e.flt_mantissa.flt_h_32 == 0xffffffff) {
 192                                         e.flt_exp++;
 193                                         e.flt_mantissa.flt_h_32 = 0x80000000;
 194                                 }
 195                                 else e.flt_mantissa.flt_h_32++;
 196                         }
 197                         else {
 198                                 e.flt_mantissa.flt_l_32 += 0x400;
 199                         }
 200                 }
 201                 if (e.flt_exp >= 2047) {
 202                         overflow = 1;
 203                         e.flt_exp = 2047;
 204                         e.flt_mantissa.flt_h_32 = e.flt_mantissa.flt_l_32 = 0;
 205                 }
 206                 if (e.flt_exp <= 0) {
 207                         flt_b64_sft(&(e.flt_mantissa), 1);
 208                         if (e.flt_exp < 0) {
 209                                 flt_b64_sft(&(e.flt_mantissa), -e.flt_exp);
 210                                 e.flt_exp = 0;
 211                         }
 212                 }
 213                 buf[I0] = (e.flt_sign << 7) | (e.flt_exp >> 4);
 214                 buf[I1] = ((e.flt_exp & 017)<< 4) | ((e.flt_mantissa.flt_h_32 >> 27) & 017);
 215                 buf[I2] = e.flt_mantissa.flt_h_32 >> 19;
 216                 buf[I3] = e.flt_mantissa.flt_h_32 >> 11;
 217                 buf[I4] = e.flt_mantissa.flt_h_32 >> 3;
 218                 buf[I5] = (e.flt_mantissa.flt_h_32 << 5) | ((e.flt_mantissa.flt_l_32 >> 27) & 037);
 219                 buf[I6] = e.flt_mantissa.flt_l_32 >> 19;
 220                 buf[I7] = e.flt_mantissa.flt_l_32 >> 11;
 221                 flt_b64_sft(&(e.flt_mantissa), -53);
 222         }
 223 #endif
 224 #if ! FL_MSL_AT_LOW_ADDRESS
 225         if (sz == 4) {
 226                 buf[I4] = buf[I0];
 227                 buf[I5] = buf[I1];
 228                 buf[I6] = buf[I2];
 229                 buf[I7] = buf[I3];
 230         }
 231 #endif
 232         if (overflow) {
 233                 return 2;
 234         }
 235         return 0;
 236 }
 237 #endif /* USE_FLT */
 238
 239 #ifdef CODE_GENERATOR
 240 con_float()
 241 {
 242         char buf[8];
 243         int rval = float_cst(str, (int)argval, buf);
 244         int i;
 245
 246         if (rval == 1) {
 247                 fprintf(stderr,"float constant size = %d\n",(int)argval);
 248                 fatal("bad fcon size");
 249         }
 250         fprintf(codefile,"!float %s sz %d\n", str, (int)argval);
 251         if (rval == 2) {
 252                 fprintf(stderr, "Warning: overflow in floating point constant %s\n", str);
 253         }
 254         fprintf(codefile, ".data1 0%o", buf[0] & 0377);
 255         for (i = 1; i < (int)argval; i++) {
 256                 fprintf(codefile, ",0%o", buf[i] & 0377);
 257         }
 258         putc('\n', codefile);
 259 }
 260 #endif /* CODE_GENERATOR */
 261
 262 #ifdef CODE_EXPANDER
 263 con_float(str, argval)
 264         char *str;
 265         arith argval;
 266 {
 267         char buf[8];
 268         int rval = float_cst(str, (int)argval, buf);
 269         int i;
 270
 271         if (rval == 1) {
 272                 argval = 8;
 273                 rval = float_cst(str, 8, buf);
 274         }
 275         for (i = 0; i < (int)argval; i++) {
 276                 gen1(buf[i]);
 277         }
 278 }
 279 #endif /* CODE_EXPANDER */