1 2 /* 3 =============================================================================== 4 5 This C header file is part of the SoftFloat IEC/IEEE Floating-point 6 Arithmetic Package, Release 2. 7 8 Written by John R. Hauser. This work was made possible in part by the 9 International Computer Science Institute, located at Suite 600, 1947 Center 10 Street, Berkeley, California 94704. Funding was partially provided by the 11 National Science Foundation under grant MIP-9311980. The original version 12 of this code was written as part of a project to build a fixed-point vector 13 processor in collaboration with the University of California at Berkeley, 14 overseen by Profs. Nelson Morgan and John Wawrzynek. More information 15 is available through the Web page `http://HTTP.CS.Berkeley.EDU/~jhauser/ 16 arithmetic/softfloat.html'. 17 18 THIS SOFTWARE IS DISTRIBUTED AS IS, FOR FREE. Although reasonable effort 19 has been made to avoid it, THIS SOFTWARE MAY CONTAIN FAULTS THAT WILL AT 20 TIMES RESULT IN INCORRECT BEHAVIOR. USE OF THIS SOFTWARE IS RESTRICTED TO 21 PERSONS AND ORGANIZATIONS WHO CAN AND WILL TAKE FULL RESPONSIBILITY FOR ANY 22 AND ALL LOSSES, COSTS, OR OTHER PROBLEMS ARISING FROM ITS USE. 23 24 Derivative works are acceptable, even for commercial purposes, so long as 25 (1) they include prominent notice that the work is derivative, and (2) they 26 include prominent notice akin to these three paragraphs for those parts of 27 this code that are retained. 28 29 =============================================================================== 30 */ 31 32 #ifndef __SOFTFLOAT_H__ 33 #define __SOFTFLOAT_H__ 34 35 #include <linux/config.h> 36 37 /* 38 ------------------------------------------------------------------------------- 39 The macro `FLOATX80' must be defined to enable the extended double-precision 40 floating-point format `floatx80'. If this macro is not defined, the 41 `floatx80' type will not be defined, and none of the functions that either 42 input or output the `floatx80' type will be defined. 43 ------------------------------------------------------------------------------- 44 */ 45 #ifdef CONFIG_FPE_NWFPE_XP 46 #define FLOATX80 47 #endif 48 49 /* 50 ------------------------------------------------------------------------------- 51 Software IEC/IEEE floating-point types. 52 ------------------------------------------------------------------------------- 53 */ 54 typedef unsigned long int float32; 55 typedef unsigned long long float64; 56 typedef struct { 57 unsigned short high; 58 unsigned long long low; 59 } floatx80; 60 61 /* 62 ------------------------------------------------------------------------------- 63 Software IEC/IEEE floating-point underflow tininess-detection mode. 64 ------------------------------------------------------------------------------- 65 */ 66 extern signed char float_detect_tininess; 67 enum { 68 float_tininess_after_rounding = 0, 69 float_tininess_before_rounding = 1 70 }; 71 72 /* 73 ------------------------------------------------------------------------------- 74 Software IEC/IEEE floating-point rounding mode. 75 ------------------------------------------------------------------------------- 76 */ 77 extern signed char float_rounding_mode; 78 enum { 79 float_round_nearest_even = 0, 80 float_round_to_zero = 1, 81 float_round_down = 2, 82 float_round_up = 3 83 }; 84 85 /* 86 ------------------------------------------------------------------------------- 87 Software IEC/IEEE floating-point exception flags. 88 ------------------------------------------------------------------------------- 89 extern signed char float_exception_flags; 90 enum { 91 float_flag_inexact = 1, 92 float_flag_underflow = 2, 93 float_flag_overflow = 4, 94 float_flag_divbyzero = 8, 95 float_flag_invalid = 16 96 }; 97 98 ScottB: November 4, 1998 99 Changed the enumeration to match the bit order in the FPA11. 100 */ 101 102 extern signed char float_exception_flags; 103 enum { 104 float_flag_invalid = 1, 105 float_flag_divbyzero = 2, 106 float_flag_overflow = 4, 107 float_flag_underflow = 8, 108 float_flag_inexact = 16 109 }; 110 111 /* 112 ------------------------------------------------------------------------------- 113 Routine to raise any or all of the software IEC/IEEE floating-point 114 exception flags. 115 ------------------------------------------------------------------------------- 116 */ 117 void float_raise( signed char ); 118 119 /* 120 ------------------------------------------------------------------------------- 121 Software IEC/IEEE integer-to-floating-point conversion routines. 122 ------------------------------------------------------------------------------- 123 */ 124 float32 int32_to_float32( signed int ); 125 float64 int32_to_float64( signed int ); 126 #ifdef FLOATX80 127 floatx80 int32_to_floatx80( signed int ); 128 #endif 129 130 /* 131 ------------------------------------------------------------------------------- 132 Software IEC/IEEE single-precision conversion routines. 133 ------------------------------------------------------------------------------- 134 */ 135 signed int float32_to_int32( float32 ); 136 signed int float32_to_int32_round_to_zero( float32 ); 137 float64 float32_to_float64( float32 ); 138 #ifdef FLOATX80 139 floatx80 float32_to_floatx80( float32 ); 140 #endif 141 142 /* 143 ------------------------------------------------------------------------------- 144 Software IEC/IEEE single-precision operations. 145 ------------------------------------------------------------------------------- 146 */ 147 float32 float32_round_to_int( float32 ); 148 float32 float32_add( float32, float32 ); 149 float32 float32_sub( float32, float32 ); 150 float32 float32_mul( float32, float32 ); 151 float32 float32_div( float32, float32 ); 152 float32 float32_rem( float32, float32 ); 153 float32 float32_sqrt( float32 ); 154 char float32_eq( float32, float32 ); 155 char float32_le( float32, float32 ); 156 char float32_lt( float32, float32 ); 157 char float32_eq_signaling( float32, float32 ); 158 char float32_le_quiet( float32, float32 ); 159 char float32_lt_quiet( float32, float32 ); 160 char float32_is_signaling_nan( float32 ); 161 162 /* 163 ------------------------------------------------------------------------------- 164 Software IEC/IEEE double-precision conversion routines. 165 ------------------------------------------------------------------------------- 166 */ 167 signed int float64_to_int32( float64 ); 168 signed int float64_to_int32_round_to_zero( float64 ); 169 float32 float64_to_float32( float64 ); 170 #ifdef FLOATX80 171 floatx80 float64_to_floatx80( float64 ); 172 #endif 173 174 /* 175 ------------------------------------------------------------------------------- 176 Software IEC/IEEE double-precision operations. 177 ------------------------------------------------------------------------------- 178 */ 179 float64 float64_round_to_int( float64 ); 180 float64 float64_add( float64, float64 ); 181 float64 float64_sub( float64, float64 ); 182 float64 float64_mul( float64, float64 ); 183 float64 float64_div( float64, float64 ); 184 float64 float64_rem( float64, float64 ); 185 float64 float64_sqrt( float64 ); 186 char float64_eq( float64, float64 ); 187 char float64_le( float64, float64 ); 188 char float64_lt( float64, float64 ); 189 char float64_eq_signaling( float64, float64 ); 190 char float64_le_quiet( float64, float64 ); 191 char float64_lt_quiet( float64, float64 ); 192 char float64_is_signaling_nan( float64 ); 193 194 #ifdef FLOATX80 195 196 /* 197 ------------------------------------------------------------------------------- 198 Software IEC/IEEE extended double-precision conversion routines. 199 ------------------------------------------------------------------------------- 200 */ 201 signed int floatx80_to_int32( floatx80 ); 202 signed int floatx80_to_int32_round_to_zero( floatx80 ); 203 float32 floatx80_to_float32( floatx80 ); 204 float64 floatx80_to_float64( floatx80 ); 205 206 /* 207 ------------------------------------------------------------------------------- 208 Software IEC/IEEE extended double-precision rounding precision. Valid 209 values are 32, 64, and 80. 210 ------------------------------------------------------------------------------- 211 */ 212 extern signed char floatx80_rounding_precision; 213 214 /* 215 ------------------------------------------------------------------------------- 216 Software IEC/IEEE extended double-precision operations. 217 ------------------------------------------------------------------------------- 218 */ 219 floatx80 floatx80_round_to_int( floatx80 ); 220 floatx80 floatx80_add( floatx80, floatx80 ); 221 floatx80 floatx80_sub( floatx80, floatx80 ); 222 floatx80 floatx80_mul( floatx80, floatx80 ); 223 floatx80 floatx80_div( floatx80, floatx80 ); 224 floatx80 floatx80_rem( floatx80, floatx80 ); 225 floatx80 floatx80_sqrt( floatx80 ); 226 char floatx80_eq( floatx80, floatx80 ); 227 char floatx80_le( floatx80, floatx80 ); 228 char floatx80_lt( floatx80, floatx80 ); 229 char floatx80_eq_signaling( floatx80, floatx80 ); 230 char floatx80_le_quiet( floatx80, floatx80 ); 231 char floatx80_lt_quiet( floatx80, floatx80 ); 232 char floatx80_is_signaling_nan( floatx80 ); 233 234 #endif 235 236 static inline flag extractFloat32Sign(float32 a) 237 { 238 return a >> 31; 239 } 240 241 static inline flag float32_eq_nocheck(float32 a, float32 b) 242 { 243 return (a == b) || ((bits32) ((a | b) << 1) == 0); 244 } 245 246 static inline flag float32_lt_nocheck(float32 a, float32 b) 247 { 248 flag aSign, bSign; 249 250 aSign = extractFloat32Sign(a); 251 bSign = extractFloat32Sign(b); 252 if (aSign != bSign) 253 return aSign && ((bits32) ((a | b) << 1) != 0); 254 return (a != b) && (aSign ^ (a < b)); 255 } 256 257 static inline flag extractFloat64Sign(float64 a) 258 { 259 return a >> 63; 260 } 261 262 static inline flag float64_eq_nocheck(float64 a, float64 b) 263 { 264 return (a == b) || ((bits64) ((a | b) << 1) == 0); 265 } 266 267 static inline flag float64_lt_nocheck(float64 a, float64 b) 268 { 269 flag aSign, bSign; 270 271 aSign = extractFloat64Sign(a); 272 bSign = extractFloat64Sign(b); 273 if (aSign != bSign) 274 return aSign && ((bits64) ((a | b) << 1) != 0); 275 return (a != b) && (aSign ^ (a < b)); 276 } 277 278 #endif 279