tests/tcg/arm/fcvt.c

   1 /*
   2  * Test Floating Point Conversion
   3  */
   4
   5 /* we want additional float type definitions */
   6 #define __STDC_WANT_IEC_60559_BFP_EXT__
   7 #define __STDC_WANT_IEC_60559_TYPES_EXT__
   8
   9 #include <stdio.h>
  10 #include <inttypes.h>
  11 #include <math.h>
  12 #include <float.h>
  13 #include <fenv.h>
  14
  15 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
  16
  17 static char flag_str[256];
  18
  19 static char *get_flag_state(int flags)
  20 {
  21     if (flags) {
  22         snprintf(flag_str, sizeof(flag_str), "%s %s %s %s %s",
  23                  flags & FE_OVERFLOW ? "OVERFLOW" : "",
  24                  flags & FE_UNDERFLOW ? "UNDERFLOW" : "",
  25                  flags & FE_DIVBYZERO ? "DIV0" : "",
  26                  flags & FE_INEXACT ? "INEXACT" : "",
  27                  flags & FE_INVALID ? "INVALID" : "");
  28     } else {
  29         snprintf(flag_str, sizeof(flag_str), "OK");
  30     }
  31
  32     return flag_str;
  33 }
  34
  35 static void print_double_number(int i, double num)
  36 {
  37     uint64_t double_as_hex = *(uint64_t *) &num;
  38     int flags = fetestexcept(FE_ALL_EXCEPT);
  39     char *fstr = get_flag_state(flags);
  40
  41     printf("%02d DOUBLE: %02.20e / %#020" PRIx64 " (%#x => %s)\n",
  42            i, num, double_as_hex, flags, fstr);
  43 }
  44
  45 static void print_single_number(int i, float num)
  46 {
  47     uint32_t single_as_hex = *(uint32_t *) &num;
  48     int flags = fetestexcept(FE_ALL_EXCEPT);
  49     char *fstr = get_flag_state(flags);
  50
  51     printf("%02d SINGLE: %02.20e / %#010x  (%#x => %s)\n",
  52            i, num, single_as_hex, flags, fstr);
  53 }
  54
  55 static void print_half_number(int i, uint16_t num)
  56 {
  57     int flags = fetestexcept(FE_ALL_EXCEPT);
  58     char *fstr = get_flag_state(flags);
  59
  60     printf("%02d   HALF: %#04x  (%#x => %s)\n",
  61            i, num, flags, fstr);
  62 }
  63
  64 static void print_int64(int i, int64_t num)
  65 {
  66     uint64_t int64_as_hex = *(uint64_t *) &num;
  67     int flags = fetestexcept(FE_ALL_EXCEPT);
  68     char *fstr = get_flag_state(flags);
  69
  70     printf("%02d   INT64: %20" PRId64 "/%#020" PRIx64 " (%#x => %s)\n",
  71            i, num, int64_as_hex, flags, fstr);
  72 }
  73
  74 #ifndef SNANF
  75 /* Signaling NaN macros, if supported.  */
  76 # define SNANF (__builtin_nansf (""))
  77 # define SNAN (__builtin_nans (""))
  78 # define SNANL (__builtin_nansl (""))
  79 #endif
  80
  81 float single_numbers[] = { -SNANF,
  82                            -NAN,
  83                            -INFINITY,
  84                            -FLT_MAX,
  85                            -1.111E+31,
  86                            -1.111E+30,
  87                            -1.08700982e-12,
  88                            -1.78051176e-20,
  89                            -FLT_MIN,
  90                            0.0,
  91                            FLT_MIN,
  92                            2.98023224e-08,
  93                            5.96046E-8, /* min positive FP16 subnormal */
  94                            6.09756E-5, /* max subnormal FP16 */
  95                            6.10352E-5, /* min positive normal FP16 */
  96                            1.0,
  97                            1.0009765625, /* smallest float after 1.0 FP16 */
  98                            2.0,
  99                            M_E, M_PI,
 100                            65503.0,
 101                            65504.0, /* max FP16 */
 102                            65505.0,
 103                            131007.0,
 104                            131008.0, /* max AFP */
 105                            131009.0,
 106                            1.111E+30,
 107                            FLT_MAX,
 108                            INFINITY,
 109                            NAN,
 110                            SNANF };
 111
 112 static void convert_single_to_half(void)
 113 {
 114     int i;
 115
 116     printf("Converting single-precision to half-precision\n");
 117
 118     for (i = 0; i < ARRAY_SIZE(single_numbers); ++i) {
 119         float input = single_numbers[i];
 120
 121         feclearexcept(FE_ALL_EXCEPT);
 122
 123         print_single_number(i, input);
 124 #if defined(__arm__)
 125         uint32_t output;
 126         asm("vcvtb.f16.f32 %0, %1" : "=t" (output) : "x" (input));
 127 #else
 128         uint16_t output;
 129         asm("fcvt %h0, %s1" : "=w" (output) : "w" (input));
 130 #endif
 131         print_half_number(i, output);
 132     }
 133 }
 134
 135 static void convert_single_to_double(void)
 136 {
 137     int i;
 138
 139     printf("Converting single-precision to double-precision\n");
 140
 141     for (i = 0; i < ARRAY_SIZE(single_numbers); ++i) {
 142         float input = single_numbers[i];
 143         /* uint64_t output; */
 144         double output;
 145
 146         feclearexcept(FE_ALL_EXCEPT);
 147
 148         print_single_number(i, input);
 149 #if defined(__arm__)
 150         asm("vcvt.f64.f32 %P0, %1" : "=w" (output) : "t" (input));
 151 #else
 152         asm("fcvt %d0, %s1" : "=w" (output) : "w" (input));
 153 #endif
 154         print_double_number(i, output);
 155     }
 156 }
 157
 158 static void convert_single_to_integer(void)
 159 {
 160     int i;
 161
 162     printf("Converting single-precision to integer\n");
 163
 164     for (i = 0; i < ARRAY_SIZE(single_numbers); ++i) {
 165         float input = single_numbers[i];
 166         int64_t output;
 167
 168         feclearexcept(FE_ALL_EXCEPT);
 169
 170         print_single_number(i, input);
 171 #if defined(__arm__)
 172         /* asm("vcvt.s32.f32 %s0, %s1" : "=t" (output) : "t" (input)); */
 173         output = input;
 174 #else
 175         asm("fcvtzs %0, %s1" : "=r" (output) : "w" (input));
 176 #endif
 177         print_int64(i, output);
 178     }
 179 }
 180
 181 /* This allows us to initialise some doubles as pure hex */
 182 typedef union {
 183     double d;
 184     uint64_t h;
 185 } test_doubles;
 186
 187 test_doubles double_numbers[] = {
 188     {SNAN},
 189     {-NAN},
 190     {-INFINITY},
 191     {-DBL_MAX},
 192     {-FLT_MAX-1.0},
 193     {-FLT_MAX},
 194     {-1.111E+31},
 195     {-1.111E+30}, /* half prec */
 196     {-2.0}, {-1.0},
 197     {-DBL_MIN},
 198     {-FLT_MIN},
 199     {0.0},
 200     {FLT_MIN},
 201     {2.98023224e-08},
 202     {5.96046E-8}, /* min positive FP16 subnormal */
 203     {6.09756E-5}, /* max subnormal FP16 */
 204     {6.10352E-5}, /* min positive normal FP16 */
 205     {1.0},
 206     {1.0009765625}, /* smallest float after 1.0 FP16 */
 207     {DBL_MIN},
 208     {1.3789972848607228e-308},
 209     {1.4914738736681624e-308},
 210     {1.0}, {2.0},
 211     {M_E}, {M_PI},
 212     {65503.0},
 213     {65504.0}, /* max FP16 */
 214     {65505.0},
 215     {131007.0},
 216     {131008.0}, /* max AFP */
 217     {131009.0},
 218     {.h = 0x41dfffffffc00000 }, /* to int = 0x7fffffff */
 219     {FLT_MAX},
 220     {FLT_MAX + 1.0},
 221     {DBL_MAX},
 222     {INFINITY},
 223     {NAN},
 224     {.h = 0x7ff0000000000001}, /* SNAN */
 225     {SNAN},
 226 };
 227
 228 static void convert_double_to_half(void)
 229 {
 230     int i;
 231
 232     printf("Converting double-precision to half-precision\n");
 233
 234     for (i = 0; i < ARRAY_SIZE(double_numbers); ++i) {
 235         double input = double_numbers[i].d;
 236         uint16_t output;
 237
 238         feclearexcept(FE_ALL_EXCEPT);
 239
 240         print_double_number(i, input);
 241
 242         /* as we don't have _Float16 support */
 243 #if defined(__arm__)
 244         /* asm("vcvtb.f16.f64 %0, %P1" : "=t" (output) : "x" (input)); */
 245         output = input;
 246 #else
 247         asm("fcvt %h0, %d1" : "=w" (output) : "w" (input));
 248 #endif
 249         print_half_number(i, output);
 250     }
 251 }
 252
 253 static void convert_double_to_single(void)
 254 {
 255     int i;
 256
 257     printf("Converting double-precision to single-precision\n");
 258
 259     for (i = 0; i < ARRAY_SIZE(double_numbers); ++i) {
 260         double input = double_numbers[i].d;
 261         float output;
 262
 263         feclearexcept(FE_ALL_EXCEPT);
 264
 265         print_double_number(i, input);
 266
 267 #if defined(__arm__)
 268         asm("vcvt.f32.f64 %0, %P1" : "=w" (output) : "x" (input));
 269 #else
 270         asm("fcvt %s0, %d1" : "=w" (output) : "w" (input));
 271 #endif
 272
 273         print_single_number(i, output);
 274     }
 275 }
 276
 277 static void convert_double_to_integer(void)
 278 {
 279     int i;
 280
 281     printf("Converting double-precision to integer\n");
 282
 283     for (i = 0; i < ARRAY_SIZE(double_numbers); ++i) {
 284         double input = double_numbers[i].d;
 285         int64_t output;
 286
 287         feclearexcept(FE_ALL_EXCEPT);
 288
 289         print_double_number(i, input);
 290 #if defined(__arm__)
 291         /* asm("vcvt.s32.f32 %s0, %s1" : "=t" (output) : "t" (input)); */
 292         output = input;
 293 #else
 294         asm("fcvtzs %0, %d1" : "=r" (output) : "w" (input));
 295 #endif
 296         print_int64(i, output);
 297     }
 298 }
 299
 300 /* no handy defines for these numbers */
 301 uint16_t half_numbers[] = {
 302     0xffff, /* -NaN / AHP -Max */
 303     0xfcff, /* -NaN / AHP */
 304     0xfc01, /* -NaN / AHP */
 305     0xfc00, /* -Inf */
 306     0xfbff, /* -Max */
 307     0xc000, /* -2 */
 308     0xbc00, /* -1 */
 309     0x8001, /* -MIN subnormal */
 310     0x8000, /* -0 */
 311     0x0000, /* +0 */
 312     0x0001, /* MIN subnormal */
 313     0x3c00, /* 1 */
 314     0x7bff, /* Max */
 315     0x7c00, /* Inf */
 316     0x7c01, /* NaN / AHP */
 317     0x7cff, /* NaN / AHP */
 318     0x7fff, /* NaN / AHP +Max*/
 319 };
 320
 321 static void convert_half_to_double(void)
 322 {
 323     int i;
 324
 325     printf("Converting half-precision to double-precision\n");
 326
 327     for (i = 0; i < ARRAY_SIZE(half_numbers); ++i) {
 328         uint16_t input = half_numbers[i];
 329         double output;
 330
 331         feclearexcept(FE_ALL_EXCEPT);
 332
 333         print_half_number(i, input);
 334 #if defined(__arm__)
 335         /* asm("vcvtb.f64.f16 %P0, %1" : "=w" (output) : "t" (input)); */
 336         output = input;
 337 #else
 338         asm("fcvt %d0, %h1" : "=w" (output) : "w" (input));
 339 #endif
 340         print_double_number(i, output);
 341     }
 342 }
 343
 344 static void convert_half_to_single(void)
 345 {
 346     int i;
 347
 348     printf("Converting half-precision to single-precision\n");
 349
 350     for (i = 0; i < ARRAY_SIZE(half_numbers); ++i) {
 351         uint16_t input = half_numbers[i];
 352         float output;
 353
 354         feclearexcept(FE_ALL_EXCEPT);
 355
 356         print_half_number(i, input);
 357 #if defined(__arm__)
 358         /*
 359          * Clang refuses to allocate an integer to a fp register.
 360          * Perform the move from a general register by hand.
 361          */
 362         asm("vmov %0, %1\n\t"
 363             "vcvtb.f32.f16 %0, %0" : "=w" (output) : "r" (input));
 364 #else
 365         asm("fcvt %s0, %h1" : "=w" (output) : "w" (input));
 366 #endif
 367         print_single_number(i, output);
 368     }
 369 }
 370
 371 static void convert_half_to_integer(void)
 372 {
 373     int i;
 374
 375     printf("Converting half-precision to integer\n");
 376
 377     for (i = 0; i < ARRAY_SIZE(half_numbers); ++i) {
 378         uint16_t input = half_numbers[i];
 379         int64_t output;
 380
 381         feclearexcept(FE_ALL_EXCEPT);
 382
 383         print_half_number(i, input);
 384 #if defined(__arm__)
 385         /* asm("vcvt.s32.f16 %0, %1" : "=t" (output) : "t" (input)); v8.2*/
 386         output = input;
 387 #else
 388         asm("fcvt %s0, %h1" : "=w" (output) : "w" (input));
 389 #endif
 390         print_int64(i, output);
 391     }
 392 }
 393
 394 typedef struct {
 395     int flag;
 396     char *desc;
 397 } float_mapping;
 398
 399 float_mapping round_flags[] = {
 400     { FE_TONEAREST, "to nearest" },
 401     { FE_UPWARD, "upwards" },
 402     { FE_DOWNWARD, "downwards" },
 403     { FE_TOWARDZERO, "to zero" }
 404 };
 405
 406 int main(int argc, char *argv[argc])
 407 {
 408     int i;
 409
 410     printf("#### Enabling IEEE Half Precision\n");
 411
 412     for (i = 0; i < ARRAY_SIZE(round_flags); ++i) {
 413         fesetround(round_flags[i].flag);
 414         printf("### Rounding %s\n", round_flags[i].desc);
 415         convert_single_to_half();
 416         convert_single_to_double();
 417         convert_double_to_half();
 418         convert_double_to_single();
 419         convert_half_to_single();
 420         convert_half_to_double();
 421     }
 422
 423     /* convert to integer */
 424     convert_single_to_integer();
 425     convert_double_to_integer();
 426     convert_half_to_integer();
 427
 428     /* And now with ARM alternative FP16 */
 429 #if defined(__arm__)
 430     asm("vmrs r1, fpscr\n\t"
 431         "orr r1, r1, %[flags]\n\t"
 432         "vmsr fpscr, r1"
 433         : /* no output */ : [flags] "n" (1 << 26) : "r1" );
 434 #else
 435     asm("mrs x1, fpcr\n\t"
 436         "orr x1, x1, %[flags]\n\t"
 437         "msr fpcr, x1\n\t"
 438         : /* no output */ : [flags] "n" (1 << 26) : "x1" );
 439 #endif
 440
 441     printf("#### Enabling ARM Alternative Half Precision\n");
 442
 443     for (i = 0; i < ARRAY_SIZE(round_flags); ++i) {
 444         fesetround(round_flags[i].flag);
 445         printf("### Rounding %s\n", round_flags[i].desc);
 446         convert_single_to_half();
 447         convert_single_to_double();
 448         convert_double_to_half();
 449         convert_double_to_single();
 450         convert_half_to_single();
 451         convert_half_to_double();
 452     }
 453
 454     /* convert to integer */
 455     convert_single_to_integer();
 456     convert_double_to_integer();
 457     convert_half_to_integer();
 458
 459     return 0;
 460 }