include/qemu/host-utils.h

   1 /*
   2  * Utility compute operations used by translated code.
   3  *
   4  * Copyright (c) 2007 Thiemo Seufer
   5  * Copyright (c) 2007 Jocelyn Mayer
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a copy
   8  * of this software and associated documentation files (the "Software"), to deal
   9  * in the Software without restriction, including without limitation the rights
  10  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  11  * copies of the Software, and to permit persons to whom the Software is
  12  * furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included in
  15  * all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  23  * THE SOFTWARE.
  24  */
  25 #ifndef HOST_UTILS_H
  26 #define HOST_UTILS_H 1
  27
  28 #include "qemu/compiler.h"   /* QEMU_GNUC_PREREQ */
  29 #include <limits.h>
  30
  31 #ifdef CONFIG_INT128
  32 static inline void mulu64(uint64_t *plow, uint64_t *phigh,
  33                           uint64_t a, uint64_t b)
  34 {
  35     __uint128_t r = (__uint128_t)a * b;
  36     *plow = r;
  37     *phigh = r >> 64;
  38 }
  39
  40 static inline void muls64(uint64_t *plow, uint64_t *phigh,
  41                           int64_t a, int64_t b)
  42 {
  43     __int128_t r = (__int128_t)a * b;
  44     *plow = r;
  45     *phigh = r >> 64;
  46 }
  47 #else
  48 void muls64(uint64_t *phigh, uint64_t *plow, int64_t a, int64_t b);
  49 void mulu64(uint64_t *phigh, uint64_t *plow, uint64_t a, uint64_t b);
  50 #endif
  51
  52 /**
  53  * clz32 - count leading zeros in a 32-bit value.
  54  * @val: The value to search
  55  *
  56  * Returns 32 if the value is zero.  Note that the GCC builtin is
  57  * undefined if the value is zero.
  58  */
  59 static inline int clz32(uint32_t val)
  60 {
  61 #if QEMU_GNUC_PREREQ(3, 4)
  62     return val ? __builtin_clz(val) : 32;
  63 #else
  64     /* Binary search for the leading one bit.  */
  65     int cnt = 0;
  66
  67     if (!(val & 0xFFFF0000U)) {
  68         cnt += 16;
  69         val <<= 16;
  70     }
  71     if (!(val & 0xFF000000U)) {
  72         cnt += 8;
  73         val <<= 8;
  74     }
  75     if (!(val & 0xF0000000U)) {
  76         cnt += 4;
  77         val <<= 4;
  78     }
  79     if (!(val & 0xC0000000U)) {
  80         cnt += 2;
  81         val <<= 2;
  82     }
  83     if (!(val & 0x80000000U)) {
  84         cnt++;
  85         val <<= 1;
  86     }
  87     if (!(val & 0x80000000U)) {
  88         cnt++;
  89     }
  90     return cnt;
  91 #endif
  92 }
  93
  94 /**
  95  * clo32 - count leading ones in a 32-bit value.
  96  * @val: The value to search
  97  *
  98  * Returns 32 if the value is -1.
  99  */
 100 static inline int clo32(uint32_t val)
 101 {
 102     return clz32(~val);
 103 }
 104
 105 /**
 106  * clz64 - count leading zeros in a 64-bit value.
 107  * @val: The value to search
 108  *
 109  * Returns 64 if the value is zero.  Note that the GCC builtin is
 110  * undefined if the value is zero.
 111  */
 112 static inline int clz64(uint64_t val)
 113 {
 114 #if QEMU_GNUC_PREREQ(3, 4)
 115     return val ? __builtin_clzll(val) : 64;
 116 #else
 117     int cnt = 0;
 118
 119     if (!(val >> 32)) {
 120         cnt += 32;
 121     } else {
 122         val >>= 32;
 123     }
 124
 125     return cnt + clz32(val);
 126 #endif
 127 }
 128
 129 /**
 130  * clo64 - count leading ones in a 64-bit value.
 131  * @val: The value to search
 132  *
 133  * Returns 64 if the value is -1.
 134  */
 135 static inline int clo64(uint64_t val)
 136 {
 137     return clz64(~val);
 138 }
 139
 140 /**
 141  * ctz32 - count trailing zeros in a 32-bit value.
 142  * @val: The value to search
 143  *
 144  * Returns 32 if the value is zero.  Note that the GCC builtin is
 145  * undefined if the value is zero.
 146  */
 147 static inline int ctz32(uint32_t val)
 148 {
 149 #if QEMU_GNUC_PREREQ(3, 4)
 150     return val ? __builtin_ctz(val) : 32;
 151 #else
 152     /* Binary search for the trailing one bit.  */
 153     int cnt;
 154
 155     cnt = 0;
 156     if (!(val & 0x0000FFFFUL)) {
 157         cnt += 16;
 158         val >>= 16;
 159     }
 160     if (!(val & 0x000000FFUL)) {
 161         cnt += 8;
 162         val >>= 8;
 163     }
 164     if (!(val & 0x0000000FUL)) {
 165         cnt += 4;
 166         val >>= 4;
 167     }
 168     if (!(val & 0x00000003UL)) {
 169         cnt += 2;
 170         val >>= 2;
 171     }
 172     if (!(val & 0x00000001UL)) {
 173         cnt++;
 174         val >>= 1;
 175     }
 176     if (!(val & 0x00000001UL)) {
 177         cnt++;
 178     }
 179
 180     return cnt;
 181 #endif
 182 }
 183
 184 /**
 185  * cto32 - count trailing ones in a 32-bit value.
 186  * @val: The value to search
 187  *
 188  * Returns 32 if the value is -1.
 189  */
 190 static inline int cto32(uint32_t val)
 191 {
 192     return ctz32(~val);
 193 }
 194
 195 /**
 196  * ctz64 - count trailing zeros in a 64-bit value.
 197  * @val: The value to search
 198  *
 199  * Returns 64 if the value is zero.  Note that the GCC builtin is
 200  * undefined if the value is zero.
 201  */
 202 static inline int ctz64(uint64_t val)
 203 {
 204 #if QEMU_GNUC_PREREQ(3, 4)
 205     return val ? __builtin_ctzll(val) : 64;
 206 #else
 207     int cnt;
 208
 209     cnt = 0;
 210     if (!((uint32_t)val)) {
 211         cnt += 32;
 212         val >>= 32;
 213     }
 214
 215     return cnt + ctz32(val);
 216 #endif
 217 }
 218
 219 /**
 220  * ctz64 - count trailing ones in a 64-bit value.
 221  * @val: The value to search
 222  *
 223  * Returns 64 if the value is -1.
 224  */
 225 static inline int cto64(uint64_t val)
 226 {
 227     return ctz64(~val);
 228 }
 229
 230 /**
 231  * clrsb32 - count leading redundant sign bits in a 32-bit value.
 232  * @val: The value to search
 233  *
 234  * Returns the number of bits following the sign bit that are equal to it.
 235  * No special cases; output range is [0-31].
 236  */
 237 static inline int clrsb32(uint32_t val)
 238 {
 239 #if QEMU_GNUC_PREREQ(4, 7)
 240     return __builtin_clrsb(val);
 241 #else
 242     return clz32(val ^ ((int32_t)val >> 1)) - 1;
 243 #endif
 244 }
 245
 246 /**
 247  * clrsb64 - count leading redundant sign bits in a 64-bit value.
 248  * @val: The value to search
 249  *
 250  * Returns the number of bits following the sign bit that are equal to it.
 251  * No special cases; output range is [0-63].
 252  */
 253 static inline int clrsb64(uint64_t val)
 254 {
 255 #if QEMU_GNUC_PREREQ(4, 7)
 256     return __builtin_clrsbll(val);
 257 #else
 258     return clz64(val ^ ((int64_t)val >> 1)) - 1;
 259 #endif
 260 }
 261
 262 /**
 263  * ctpop8 - count the population of one bits in an 8-bit value.
 264  * @val: The value to search
 265  */
 266 static inline int ctpop8(uint8_t val)
 267 {
 268 #if QEMU_GNUC_PREREQ(3, 4)
 269     return __builtin_popcount(val);
 270 #else
 271     val = (val & 0x55) + ((val >> 1) & 0x55);
 272     val = (val & 0x33) + ((val >> 2) & 0x33);
 273     val = (val & 0x0f) + ((val >> 4) & 0x0f);
 274
 275     return val;
 276 #endif
 277 }
 278
 279 /**
 280  * ctpop16 - count the population of one bits in a 16-bit value.
 281  * @val: The value to search
 282  */
 283 static inline int ctpop16(uint16_t val)
 284 {
 285 #if QEMU_GNUC_PREREQ(3, 4)
 286     return __builtin_popcount(val);
 287 #else
 288     val = (val & 0x5555) + ((val >> 1) & 0x5555);
 289     val = (val & 0x3333) + ((val >> 2) & 0x3333);
 290     val = (val & 0x0f0f) + ((val >> 4) & 0x0f0f);
 291     val = (val & 0x00ff) + ((val >> 8) & 0x00ff);
 292
 293     return val;
 294 #endif
 295 }
 296
 297 /**
 298  * ctpop32 - count the population of one bits in a 32-bit value.
 299  * @val: The value to search
 300  */
 301 static inline int ctpop32(uint32_t val)
 302 {
 303 #if QEMU_GNUC_PREREQ(3, 4)
 304     return __builtin_popcount(val);
 305 #else
 306     val = (val & 0x55555555) + ((val >>  1) & 0x55555555);
 307     val = (val & 0x33333333) + ((val >>  2) & 0x33333333);
 308     val = (val & 0x0f0f0f0f) + ((val >>  4) & 0x0f0f0f0f);
 309     val = (val & 0x00ff00ff) + ((val >>  8) & 0x00ff00ff);
 310     val = (val & 0x0000ffff) + ((val >> 16) & 0x0000ffff);
 311
 312     return val;
 313 #endif
 314 }
 315
 316 /**
 317  * ctpop64 - count the population of one bits in a 64-bit value.
 318  * @val: The value to search
 319  */
 320 static inline int ctpop64(uint64_t val)
 321 {
 322 #if QEMU_GNUC_PREREQ(3, 4)
 323     return __builtin_popcountll(val);
 324 #else
 325     val = (val & 0x5555555555555555ULL) + ((val >>  1) & 0x5555555555555555ULL);
 326     val = (val & 0x3333333333333333ULL) + ((val >>  2) & 0x3333333333333333ULL);
 327     val = (val & 0x0f0f0f0f0f0f0f0fULL) + ((val >>  4) & 0x0f0f0f0f0f0f0f0fULL);
 328     val = (val & 0x00ff00ff00ff00ffULL) + ((val >>  8) & 0x00ff00ff00ff00ffULL);
 329     val = (val & 0x0000ffff0000ffffULL) + ((val >> 16) & 0x0000ffff0000ffffULL);
 330     val = (val & 0x00000000ffffffffULL) + ((val >> 32) & 0x00000000ffffffffULL);
 331
 332     return val;
 333 #endif
 334 }
 335
 336 /* Host type specific sizes of these routines.  */
 337
 338 #if ULONG_MAX == UINT32_MAX
 339 # define clzl   clz32
 340 # define ctzl   ctz32
 341 # define clol   clo32
 342 # define ctol   cto32
 343 # define ctpopl ctpop32
 344 #elif ULONG_MAX == UINT64_MAX
 345 # define clzl   clz64
 346 # define ctzl   ctz64
 347 # define clol   clo64
 348 # define ctol   cto64
 349 # define ctpopl ctpop64
 350 #else
 351 # error Unknown sizeof long
 352 #endif
 353
 354 #endif