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|  | 1 | +//===--- rounding.c --Tests for changing rounding mode ----------*- C++ -*-===// | 
|  | 2 | +// | 
|  | 3 | +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. | 
|  | 4 | +// See https://llvm.org/LICENSE.txt for license information. | 
|  | 5 | +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception | 
|  | 6 | +// | 
|  | 7 | +//===----------------------------------------------------------------------===// | 
|  | 8 | +// | 
|  | 9 | +// Checks setting/getting rounding mode using builtin functions | 
|  | 10 | +// __builtin_flt_rounds and __builtin_set_flt_rounds. | 
|  | 11 | +// | 
|  | 12 | +//===----------------------------------------------------------------------===// | 
|  | 13 | + | 
|  | 14 | +#include "rounding.h" | 
|  | 15 | +#include <stdio.h> | 
|  | 16 | + | 
|  | 17 | +#ifdef FLOAT_AVAILABLE | 
|  | 18 | +// The "base" even values. They can be represented exactly and the lest | 
|  | 19 | +// significant bit of the significand is zero. | 
|  | 20 | +float PosEvenF = 0x1p+0F; | 
|  | 21 | +float NegEvenF = -0x1p+0F; | 
|  | 22 | + | 
|  | 23 | +// The "base" odd values. They can be represented exactly and the lest | 
|  | 24 | +// significant bit of the significand is one. | 
|  | 25 | +float PosOddF = 0x1.000002p+0F; | 
|  | 26 | +float NegOddF = -0x1.000002p+0F; | 
|  | 27 | + | 
|  | 28 | +// The values closest to the base ones with higher magnitude. | 
|  | 29 | +float NextToPosEvenF = 0x1.000002p+0F; | 
|  | 30 | +float NextToNegEvenF = -0x1.000002p+0F; | 
|  | 31 | +float NextToPosOddF = 0x1.000004p+0F; | 
|  | 32 | +float NextToNegOddF = -0x1.000004p+0F; | 
|  | 33 | + | 
|  | 34 | +// Value that is half of the lest significant bit of the "base" value. | 
|  | 35 | +float PosDeltaF = 0x1.0p-24F; | 
|  | 36 | +float NegDeltaF = -0x1.0p-24F; | 
|  | 37 | +#endif | 
|  | 38 | + | 
|  | 39 | +#ifdef DOUBLE_AVAILABLE | 
|  | 40 | +double PosEvenD = 0x1p+0; | 
|  | 41 | +double NegEvenD = -0x1p+0; | 
|  | 42 | + | 
|  | 43 | +double PosOddD = 0x1.0000000000001p+0; | 
|  | 44 | +double NegOddD = -0x1.0000000000001p+0; | 
|  | 45 | + | 
|  | 46 | +double NextToPosEvenD = 0x1.0000000000001p+0; | 
|  | 47 | +double NextToNegEvenD = -0x1.0000000000001p+0; | 
|  | 48 | +double NextToPosOddD = 0x1.0000000000002p+0; | 
|  | 49 | +double NextToNegOddD = -0x1.0000000000002p+0; | 
|  | 50 | + | 
|  | 51 | +double PosDeltaD = 0x1.0p-52; | 
|  | 52 | +double NegDeltaD = -0x1.0p-52; | 
|  | 53 | +#endif | 
|  | 54 | + | 
|  | 55 | +// Check macros. They may be overriden to implement different reaction on | 
|  | 56 | +// broken condition, rather that printing a message. | 
|  | 57 | + | 
|  | 58 | +#ifndef REPORT_STAGE | 
|  | 59 | +#define REPORT_STAGE(x)   printf(x) | 
|  | 60 | +#endif | 
|  | 61 | + | 
|  | 62 | +#ifndef CHECK_INT_EQ | 
|  | 63 | +#define CHECK_INT_EQ(VExp, VAct)                                               \ | 
|  | 64 | +    if (VExp != VAct) {                                                        \ | 
|  | 65 | +      printf("Failure on line %i -  expected: %d, actual: %d\n",               \ | 
|  | 66 | +             __LINE__, VExp, VAct);                                            \ | 
|  | 67 | +    } | 
|  | 68 | +#endif | 
|  | 69 | + | 
|  | 70 | +#ifdef FLOAT_AVAILABLE | 
|  | 71 | +#ifndef CHECK_FLT_EQ | 
|  | 72 | +#define CHECK_FLT_EQ(VExp, VAct)                                               \ | 
|  | 73 | +    if (VExp != VAct) {                                                        \ | 
|  | 74 | +      printf("Failure on line %i -  expected: %a, actual: %a\n",               \ | 
|  | 75 | +             __LINE__, VExp, VAct);                                            \ | 
|  | 76 | +    } | 
|  | 77 | +#endif     | 
|  | 78 | +#endif | 
|  | 79 | + | 
|  | 80 | +#ifdef DOUBLE_AVAILABLE | 
|  | 81 | +#ifndef CHECK_DBL_EQ | 
|  | 82 | +#define CHECK_DBL_EQ(VExp, VAct)                                               \ | 
|  | 83 | +    if (VExp != VAct) {                                                        \ | 
|  | 84 | +      printf("Failure on line %i -  expected: %la, actual: %la\n",             \ | 
|  | 85 | +             __LINE__, VExp, VAct);                                            \ | 
|  | 86 | +    } | 
|  | 87 | +#endif     | 
|  | 88 | +#endif | 
|  | 89 | + | 
|  | 90 | +#ifdef FLOAT_AVAILABLE | 
|  | 91 | +static void check_float_toward_zero() { | 
|  | 92 | +  float Res; | 
|  | 93 | + | 
|  | 94 | +  Res = PosEvenF + PosDeltaF;         // Rounds down | 
|  | 95 | +  CHECK_FLT_EQ(PosEvenF, Res); | 
|  | 96 | +  Res = NegEvenF + NegDeltaF;         // Rounsd up | 
|  | 97 | +  CHECK_FLT_EQ(NegEvenF, Res); | 
|  | 98 | + | 
|  | 99 | +  Res = PosOddF + PosDeltaF;          // Rounsd down | 
|  | 100 | +  CHECK_FLT_EQ(PosOddF, Res); | 
|  | 101 | +  Res = NegOddF + NegDeltaF;          // Rounsd up | 
|  | 102 | +  CHECK_FLT_EQ(NegOddF, Res); | 
|  | 103 | +} | 
|  | 104 | + | 
|  | 105 | +static void check_float_toward_nearest() { | 
|  | 106 | +  float Res; | 
|  | 107 | + | 
|  | 108 | +  Res = PosEvenF + PosDeltaF;         // Rounsd down | 
|  | 109 | +  CHECK_FLT_EQ(PosEvenF, Res); | 
|  | 110 | +  Res = NegEvenF + NegDeltaF;         // Pounds up | 
|  | 111 | +  CHECK_FLT_EQ(NegEvenF, Res); | 
|  | 112 | + | 
|  | 113 | +  Res = PosOddF + PosDeltaF;          // Rounsd up | 
|  | 114 | +  CHECK_FLT_EQ(NextToPosOddF, Res); | 
|  | 115 | +  Res = NegOddF + NegDeltaF;          // Rounds down | 
|  | 116 | +  CHECK_FLT_EQ(NextToNegOddF, Res); | 
|  | 117 | +} | 
|  | 118 | + | 
|  | 119 | +static void check_float_upward() { | 
|  | 120 | +  float Res; | 
|  | 121 | + | 
|  | 122 | +  Res = PosEvenF + PosDeltaF;         // Rounsd up | 
|  | 123 | +  CHECK_FLT_EQ(NextToPosEvenF, Res); | 
|  | 124 | +  Res = NegEvenF + NegDeltaF;         // Pounds up | 
|  | 125 | +  CHECK_FLT_EQ(NegEvenF, Res); | 
|  | 126 | + | 
|  | 127 | +  Res = PosOddF + PosDeltaF;          // Rounsd up | 
|  | 128 | +  CHECK_FLT_EQ(NextToPosOddF, Res); | 
|  | 129 | +  Res = NegOddF + NegDeltaF;          // Rounds up | 
|  | 130 | +  CHECK_FLT_EQ(NegOddF, Res); | 
|  | 131 | +} | 
|  | 132 | + | 
|  | 133 | +static void check_float_downward() { | 
|  | 134 | +  float Res; | 
|  | 135 | + | 
|  | 136 | +  Res = PosEvenF + PosDeltaF;         // Rounsd down | 
|  | 137 | +  CHECK_FLT_EQ(PosEvenF, Res); | 
|  | 138 | +  Res = NegEvenF + NegDeltaF;         // Pounds down | 
|  | 139 | +  CHECK_FLT_EQ(NextToNegEvenF, Res); | 
|  | 140 | + | 
|  | 141 | +  Res = PosOddF + PosDeltaF;          // Rounsd down | 
|  | 142 | +  CHECK_FLT_EQ(PosOddF, Res); | 
|  | 143 | +  Res = NegOddF + NegDeltaF;          // Rounds down | 
|  | 144 | +  CHECK_FLT_EQ(NextToNegOddF, Res); | 
|  | 145 | +} | 
|  | 146 | + | 
|  | 147 | +static void check_float() { | 
|  | 148 | +  #pragma STDC FENV_ACCESS ON | 
|  | 149 | + | 
|  | 150 | +  REPORT_STAGE("Checking float\n"); | 
|  | 151 | +  float Res; | 
|  | 152 | +  int RM; | 
|  | 153 | + | 
|  | 154 | +  REPORT_STAGE("  towardzero\n"); | 
|  | 155 | +  __builtin_set_flt_rounds(ROUNDING_TOWARDZERO); | 
|  | 156 | +  RM = __builtin_flt_rounds(); | 
|  | 157 | +  CHECK_INT_EQ(ROUNDING_TOWARDZERO, RM); | 
|  | 158 | +  check_float_toward_zero(); | 
|  | 159 | +   | 
|  | 160 | +  REPORT_STAGE("  tonearest\n"); | 
|  | 161 | +  __builtin_set_flt_rounds(ROUNDING_TONEAREST); | 
|  | 162 | +  RM = __builtin_flt_rounds(); | 
|  | 163 | +  CHECK_INT_EQ(ROUNDING_TONEAREST, RM); | 
|  | 164 | +  check_float_toward_nearest(); | 
|  | 165 | +   | 
|  | 166 | +  REPORT_STAGE("  upward\n"); | 
|  | 167 | +  __builtin_set_flt_rounds(ROUNDING_UPWARD); | 
|  | 168 | +  RM = __builtin_flt_rounds(); | 
|  | 169 | +  CHECK_INT_EQ(ROUNDING_UPWARD, RM); | 
|  | 170 | +  check_float_upward(); | 
|  | 171 | +  | 
|  | 172 | +  REPORT_STAGE("  downward\n"); | 
|  | 173 | +  __builtin_set_flt_rounds(ROUNDING_DOWNWARD); | 
|  | 174 | +  RM = __builtin_flt_rounds(); | 
|  | 175 | +  CHECK_INT_EQ(ROUNDING_DOWNWARD, RM); | 
|  | 176 | +  check_float_downward(); | 
|  | 177 | + | 
|  | 178 | +  REPORT_STAGE("  towardzero (dynamic)\n"); | 
|  | 179 | +  RM = get_rounding_mode(ROUNDING_TOWARDZERO); | 
|  | 180 | +  __builtin_set_flt_rounds(RM); | 
|  | 181 | +  RM = __builtin_flt_rounds(); | 
|  | 182 | +  CHECK_INT_EQ(ROUNDING_TOWARDZERO, RM); | 
|  | 183 | +  check_float_toward_zero(); | 
|  | 184 | +   | 
|  | 185 | +  REPORT_STAGE("  tonearest (dynamic)\n"); | 
|  | 186 | +  RM = get_rounding_mode(ROUNDING_TONEAREST); | 
|  | 187 | +  __builtin_set_flt_rounds(RM); | 
|  | 188 | +  RM = __builtin_flt_rounds(); | 
|  | 189 | +  CHECK_INT_EQ(ROUNDING_TONEAREST, RM); | 
|  | 190 | +  check_float_toward_nearest(); | 
|  | 191 | +   | 
|  | 192 | +  REPORT_STAGE("  upward (dynamic)\n"); | 
|  | 193 | +  RM = get_rounding_mode(ROUNDING_UPWARD); | 
|  | 194 | +  __builtin_set_flt_rounds(RM); | 
|  | 195 | +  RM = __builtin_flt_rounds(); | 
|  | 196 | +  CHECK_INT_EQ(ROUNDING_UPWARD, RM); | 
|  | 197 | +  check_float_upward(); | 
|  | 198 | +  | 
|  | 199 | +  REPORT_STAGE("  downward (dynamic)\n"); | 
|  | 200 | +  RM = get_rounding_mode(ROUNDING_DOWNWARD); | 
|  | 201 | +  __builtin_set_flt_rounds(RM); | 
|  | 202 | +  RM = __builtin_flt_rounds(); | 
|  | 203 | +  CHECK_INT_EQ(ROUNDING_DOWNWARD, RM); | 
|  | 204 | +  check_float_downward(); | 
|  | 205 | +} | 
|  | 206 | +#else | 
|  | 207 | +static void check_float() {} | 
|  | 208 | +#endif     | 
|  | 209 | + | 
|  | 210 | +#ifdef DOUBLE_AVAILABLE | 
|  | 211 | +static void check_double_toward_zero() { | 
|  | 212 | +  double Res; | 
|  | 213 | + | 
|  | 214 | +  Res = PosEvenF + PosDeltaF;         // Rounds down | 
|  | 215 | +  CHECK_DBL_EQ(PosEvenF, Res); | 
|  | 216 | +  Res = NegEvenF + NegDeltaF;         // Rounsd up | 
|  | 217 | +  CHECK_DBL_EQ(NegEvenF, Res); | 
|  | 218 | + | 
|  | 219 | +  Res = PosOddF + PosDeltaF;          // Rounsd down | 
|  | 220 | +  CHECK_DBL_EQ(PosOddF, Res); | 
|  | 221 | +  Res = NegOddF + NegDeltaF;          // Rounsd up | 
|  | 222 | +  CHECK_DBL_EQ(NegOddF, Res); | 
|  | 223 | +} | 
|  | 224 | + | 
|  | 225 | +static void check_double_toward_nearest() { | 
|  | 226 | +  double Res; | 
|  | 227 | + | 
|  | 228 | +  Res = PosEvenF + PosDeltaF;         // Rounsd down | 
|  | 229 | +  CHECK_DBL_EQ(PosEvenF, Res); | 
|  | 230 | +  Res = NegEvenF + NegDeltaF;         // Pounds up | 
|  | 231 | +  CHECK_DBL_EQ(NegEvenF, Res); | 
|  | 232 | + | 
|  | 233 | +  Res = PosOddF + PosDeltaF;          // Rounsd up | 
|  | 234 | +  CHECK_DBL_EQ(NextToPosOddF, Res); | 
|  | 235 | +  Res = NegOddF + NegDeltaF;          // Rounds down | 
|  | 236 | +  CHECK_DBL_EQ(NextToNegOddF, Res); | 
|  | 237 | +} | 
|  | 238 | + | 
|  | 239 | +static void check_double_upward() { | 
|  | 240 | +  double Res; | 
|  | 241 | + | 
|  | 242 | +  Res = PosEvenF + PosDeltaF;         // Rounsd up | 
|  | 243 | +  CHECK_DBL_EQ(NextToPosEvenF, Res); | 
|  | 244 | +  Res = NegEvenF + NegDeltaF;         // Pounds up | 
|  | 245 | +  CHECK_DBL_EQ(NegEvenF, Res); | 
|  | 246 | + | 
|  | 247 | +  Res = PosOddF + PosDeltaF;          // Rounsd up | 
|  | 248 | +  CHECK_DBL_EQ(NextToPosOddF, Res); | 
|  | 249 | +  Res = NegOddF + NegDeltaF;          // Rounds up | 
|  | 250 | +  CHECK_DBL_EQ(NegOddF, Res); | 
|  | 251 | +} | 
|  | 252 | + | 
|  | 253 | +static void check_double_downward() { | 
|  | 254 | +  double Res; | 
|  | 255 | + | 
|  | 256 | +  Res = PosEvenF + PosDeltaF;         // Rounsd down | 
|  | 257 | +  CHECK_DBL_EQ(PosEvenF, Res); | 
|  | 258 | +  Res = NegEvenF + NegDeltaF;         // Pounds down | 
|  | 259 | +  CHECK_DBL_EQ(NextToNegEvenF, Res); | 
|  | 260 | + | 
|  | 261 | +  Res = PosOddF + PosDeltaF;          // Rounsd down | 
|  | 262 | +  CHECK_DBL_EQ(PosOddF, Res); | 
|  | 263 | +  Res = NegOddF + NegDeltaF;          // Rounds down | 
|  | 264 | +  CHECK_DBL_EQ(NextToNegOddF, Res); | 
|  | 265 | +} | 
|  | 266 | + | 
|  | 267 | +static void check_double() { | 
|  | 268 | +  #pragma STDC FENV_ACCESS ON | 
|  | 269 | + | 
|  | 270 | +  REPORT_STAGE("Checking double\n"); | 
|  | 271 | +  double Res; | 
|  | 272 | +  int RM; | 
|  | 273 | + | 
|  | 274 | +  REPORT_STAGE("  towardzero\n"); | 
|  | 275 | +  __builtin_set_flt_rounds(ROUNDING_TOWARDZERO); | 
|  | 276 | +  RM = __builtin_flt_rounds(); | 
|  | 277 | +  CHECK_INT_EQ(ROUNDING_TOWARDZERO, RM); | 
|  | 278 | +  check_double_toward_zero(); | 
|  | 279 | +   | 
|  | 280 | +  REPORT_STAGE("  tonearest\n"); | 
|  | 281 | +  __builtin_set_flt_rounds(ROUNDING_TONEAREST); | 
|  | 282 | +  RM = __builtin_flt_rounds(); | 
|  | 283 | +  CHECK_INT_EQ(ROUNDING_TONEAREST, RM); | 
|  | 284 | +  check_double_toward_nearest(); | 
|  | 285 | +   | 
|  | 286 | +  REPORT_STAGE("  upward\n"); | 
|  | 287 | +  __builtin_set_flt_rounds(ROUNDING_UPWARD); | 
|  | 288 | +  RM = __builtin_flt_rounds(); | 
|  | 289 | +  CHECK_INT_EQ(ROUNDING_UPWARD, RM); | 
|  | 290 | +  check_double_upward(); | 
|  | 291 | +  | 
|  | 292 | +  REPORT_STAGE("  downward\n"); | 
|  | 293 | +  __builtin_set_flt_rounds(ROUNDING_DOWNWARD); | 
|  | 294 | +  RM = __builtin_flt_rounds(); | 
|  | 295 | +  CHECK_INT_EQ(ROUNDING_DOWNWARD, RM); | 
|  | 296 | +  check_double_downward(); | 
|  | 297 | + | 
|  | 298 | +  REPORT_STAGE("  towardzero (dynamic)\n"); | 
|  | 299 | +  RM = get_rounding_mode(ROUNDING_TOWARDZERO); | 
|  | 300 | +  __builtin_set_flt_rounds(RM); | 
|  | 301 | +  RM = __builtin_flt_rounds(); | 
|  | 302 | +  CHECK_INT_EQ(ROUNDING_TOWARDZERO, RM); | 
|  | 303 | +  check_double_toward_zero(); | 
|  | 304 | +   | 
|  | 305 | +  REPORT_STAGE("  tonearest (dynamic)\n"); | 
|  | 306 | +  RM = get_rounding_mode(ROUNDING_TONEAREST); | 
|  | 307 | +  __builtin_set_flt_rounds(RM); | 
|  | 308 | +  RM = __builtin_flt_rounds(); | 
|  | 309 | +  CHECK_INT_EQ(ROUNDING_TONEAREST, RM); | 
|  | 310 | +  check_double_toward_nearest(); | 
|  | 311 | +   | 
|  | 312 | +  REPORT_STAGE("  upward (dynamic)\n"); | 
|  | 313 | +  RM = get_rounding_mode(ROUNDING_UPWARD); | 
|  | 314 | +  __builtin_set_flt_rounds(RM); | 
|  | 315 | +  RM = __builtin_flt_rounds(); | 
|  | 316 | +  CHECK_INT_EQ(ROUNDING_UPWARD, RM); | 
|  | 317 | +  check_double_upward(); | 
|  | 318 | +  | 
|  | 319 | +  REPORT_STAGE("  downward (dynamic)\n"); | 
|  | 320 | +  RM = get_rounding_mode(ROUNDING_DOWNWARD); | 
|  | 321 | +  __builtin_set_flt_rounds(RM); | 
|  | 322 | +  RM = __builtin_flt_rounds(); | 
|  | 323 | +  CHECK_INT_EQ(ROUNDING_DOWNWARD, RM); | 
|  | 324 | +  check_double_downward(); | 
|  | 325 | +} | 
|  | 326 | +#else | 
|  | 327 | +static void check_double() {} | 
|  | 328 | +#endif     | 
|  | 329 | + | 
|  | 330 | +int main(int argc, char *argv[]) { | 
|  | 331 | +  REPORT_STAGE("Checking rounding\n"); | 
|  | 332 | +  check_float(); | 
|  | 333 | +  check_double(); | 
|  | 334 | +} | 
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