1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #pragma ident "%Z%%M% %I% %E% SMI" 28 29 #include "lint.h" 30 #include <sys/isa_defs.h> 31 #include <floatingpoint.h> 32 #include <limits.h> 33 #include "libc.h" 34 35 /* 36 * Ensure that this "portable" code is only used on big-endian ISAs 37 */ 38 #if !defined(_BIG_ENDIAN) || defined(_LITTLE_ENDIAN) 39 #error "big-endian only!" 40 #endif 41 42 /* 43 * Convert a double precision floating point # into a 64-bit unsigned int. 44 * 45 * For compatibility with Sun's other conversion routines, pretend result 46 * is signed if input is negative. 47 */ 48 unsigned long long 49 __dtoull(double dval) 50 { 51 int i0; /* bitslam */ 52 unsigned i1; /* bitslam */ 53 int exp; /* exponent */ 54 unsigned int m0; /* most significant word of mantissa */ 55 unsigned int m1; /* least sig. word of mantissa */ 56 unsigned int _fp_current_exceptions = 0; 57 union { 58 int i[2]; 59 double d; 60 } u; 61 62 /* 63 * Extract the exponent and check boundary conditions. 64 * Notice that the exponent is equal to the bit number where 65 * we want the most significant bit to live. 66 */ 67 u.d = dval; 68 i0 = u.i[0]; 69 i1 = u.i[1]; 70 71 exp = ((i0 >> 20) & 0x7ff) - 0x3ff; 72 if (exp < 0) { 73 /* abs(x) < 1.0, so round to 0 */ 74 return ((unsigned long long)0); 75 } else if (exp > 63) { 76 /* 77 * abs(x) > MAXLLONG; return {MIN,MAX}ULLONG and as 78 * overflow, Inf, NaN set fp_invalid exception 79 */ 80 _fp_current_exceptions |= (1 << (int)fp_invalid); 81 (void) _Q_set_exception(_fp_current_exceptions); 82 if (i0 < 0) 83 return ((unsigned long long)LLONG_MIN); 84 else 85 return (ULLONG_MAX); /* MAXLONG */ 86 } 87 88 /* Extract the mantissa. */ 89 90 m0 = 0x80000000 | ((i0 << 11) & 0x7ffff800) | ((i1 >> 21) & 0x7ff); 91 m1 = i1 << 11; 92 93 /* 94 * The most significant bit of the mantissa is now in bit 63 of m0:m1. 95 * Shift right by (63 - exp) bits. 96 */ 97 switch (exp) { 98 case 63: 99 break; 100 case 31: 101 m1 = m0; 102 m0 = 0; 103 break; 104 default: 105 if (exp > 31) { 106 m1 = (m0 << (exp - 31)) | (m1 >> (63 - exp)); 107 m0 = (m0 >> (63 - exp)); 108 } else { 109 m1 = (m0 >> (31 - exp)); 110 m0 = 0; 111 } 112 break; 113 } 114 115 if (i0 < 0) { 116 if ((int)m0 < 0) { /* x < MINLLONG; return MINLLONG */ 117 m0 = 0x80000000; 118 m1 = 0; 119 } else { 120 m0 = ~m0; 121 m1 = ~m1; 122 if (++m1 == 0) 123 m0++; 124 } 125 } 126 127 (void) _Q_set_exception(_fp_current_exceptions); 128 return (((unsigned long long)m0 << 32) | m1); 129 } 130 131 /* 132 * Convert a floating point number into a 64-bit unsigned int. 133 * 134 * For compatibility with Sun's other conversion routines, pretend result 135 * is signed if input is negative. 136 */ 137 unsigned long long 138 __ftoull(float fval) 139 { 140 int i0; /* bitslam */ 141 int exp; /* exponent */ 142 unsigned int m0; /* most significant word of mantissa */ 143 unsigned int m1; /* least sig. word of mantissa */ 144 unsigned int _fp_current_exceptions = 0; 145 union { 146 int i; 147 float f; 148 } u; 149 150 /* 151 * Extract the exponent and check boundary conditions. 152 * Notice that the exponent is equal to the bit number where 153 * we want the most significant bit to live. 154 */ 155 u.f = fval; 156 i0 = u.i; 157 158 exp = ((i0 >> 23) & 0xff) - 0x7f; 159 if (exp < 0) { 160 /* abs(x) < 1.0, so round to 0 */ 161 return ((unsigned long long)0); 162 } else if (exp > 63) { 163 /* 164 * abs(x) > MAXLLONG; return {MIN,MAX}ULLONG and as 165 * overflow, Inf, NaN set fp_invalid exception 166 */ 167 _fp_current_exceptions |= (1 << (int)fp_invalid); 168 (void) _Q_set_exception(_fp_current_exceptions); 169 if (i0 < 0) 170 return ((unsigned long long)LLONG_MIN); 171 else 172 return (ULLONG_MAX); /* MAXLONG */ 173 } 174 175 /* Extract the mantissa. */ 176 177 m0 = 0x80000000 | (i0 << 8) & 0x7fffff00; 178 m1 = 0; 179 180 /* 181 * The most significant bit of the mantissa is now in bit 63 of m0:m1. 182 * Shift right by (63 - exp) bits. 183 */ 184 switch (exp) { 185 case 63: 186 break; 187 case 31: 188 m1 = m0; 189 m0 = 0; 190 break; 191 default: 192 if (exp > 31) { 193 m1 = m0 << (exp - 31); 194 m0 = (m0 >> (63 - exp)); 195 } else { 196 m1 = (m0 >> (31 - exp)); 197 m0 = 0; 198 } 199 break; 200 } 201 202 if (i0 < 0) { 203 if ((int)m0 < 0) { /* x < MINLLONG; return MINLLONG */ 204 m0 = 0x80000000; 205 m1 = 0; 206 } else { 207 m0 = ~m0; 208 m1 = ~m1; 209 if (++m1 == 0) 210 m0++; 211 } 212 } 213 214 (void) _Q_set_exception(_fp_current_exceptions); 215 return (((unsigned long long)m0 << 32) | m1); 216 } 217 218 /* 219 * Convert an extended precision floating point # into a 64-bit unsigned int. 220 * 221 * For compatibility with Sun's other conversion routines, pretend result 222 * is signed if input is negative. 223 */ 224 unsigned long long 225 _Q_qtoull(long double ld) 226 { 227 int i0; 228 unsigned int i1, i2; /* a long double is 128-bit in length */ 229 int exp; /* exponent */ 230 unsigned int m0; /* most significant word of mantissa */ 231 unsigned int m1; /* least sig. word of mantissa */ 232 unsigned int _fp_current_exceptions = 0; 233 int *plngdbl = (int *)&ld; 234 235 /* Only 96-bits of precision used */ 236 i0 = plngdbl[0]; 237 i1 = plngdbl[1]; 238 i2 = plngdbl[2]; 239 240 /* 241 * Extract the exponent and check boundary conditions. 242 * Notice that the exponent is equal to the bit number where 243 * we want the most significant bit to live. 244 */ 245 exp = ((i0 >> 16) & 0x7fff) - 0x3fff; 246 if (exp < 0) { 247 return ((long long)0); /* abs(x) < 1.0, so round to 0 */ 248 } else if (exp > 63) { 249 /* 250 * abs(x) > MAXLLONG; return {MIN,MAX}ULLONG and as 251 * overflow, Inf, NaN set fp_invalid exception 252 */ 253 _fp_current_exceptions |= (1 << (int)fp_invalid); 254 (void) _Q_set_exception(_fp_current_exceptions); 255 if (i0 < 0) 256 return ((unsigned long long)LLONG_MIN); 257 else 258 return (ULLONG_MAX); /* MAXLONG */ 259 } 260 261 /* Extract the mantissa. */ 262 263 m0 = 0x80000000 | ((i0<<15) & 0x7fff8000) | ((i1>>17) & 0x7fff); 264 m1 = (i1 << 15) | ((i2 >> 17) & 0x7fff); 265 266 /* 267 * The most significant bit of the mantissa is now in bit 63 of m0:m1. 268 * Shift right by (63 - exp) bits. 269 */ 270 switch (exp) { 271 case 63: 272 break; 273 case 31: 274 m1 = m0; 275 m0 = 0; 276 break; 277 default: 278 if (exp > 31) { 279 m1 = (m0 << (exp - 31)) | (m1 >> (63 - exp)); 280 m0 = (m0 >> (63 - exp)); 281 } else { 282 m1 = (m0 >> (31 - exp)); 283 m0 = 0; 284 } 285 break; 286 } 287 288 if (i0 < 0) { 289 if ((int)m0 < 0) { /* x < MINLLONG; return MINLLONG */ 290 m0 = 0x80000000; 291 m1 = 0; 292 } else { 293 m0 = ~m0; 294 m1 = ~m1; 295 if (++m1 == 0) 296 m0++; 297 } 298 } 299 300 (void) _Q_set_exception(_fp_current_exceptions); 301 return (((unsigned long long)m0 << 32) | m1); 302 } 303