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  * ctpop8 - count the population of one bits in an 8-bit value.
 232  * @val: The value to search
 233  */
 234 static inline int ctpop8(uint8_t val)
 235 {
 236 #if QEMU_GNUC_PREREQ(3, 4)
 237     return __builtin_popcount(val);
 238 #else
 239     val = (val & 0x55) + ((val >> 1) & 0x55);
 240     val = (val & 0x33) + ((val >> 2) & 0x33);
 241     val = (val & 0x0f) + ((val >> 4) & 0x0f);
 242
 243     return val;
 244 #endif
 245 }
 246
 247 /**
 248  * ctpop16 - count the population of one bits in a 16-bit value.
 249  * @val: The value to search
 250  */
 251 static inline int ctpop16(uint16_t val)
 252 {
 253 #if QEMU_GNUC_PREREQ(3, 4)
 254     return __builtin_popcount(val);
 255 #else
 256     val = (val & 0x5555) + ((val >> 1) & 0x5555);
 257     val = (val & 0x3333) + ((val >> 2) & 0x3333);
 258     val = (val & 0x0f0f) + ((val >> 4) & 0x0f0f);
 259     val = (val & 0x00ff) + ((val >> 8) & 0x00ff);
 260
 261     return val;
 262 #endif
 263 }
 264
 265 /**
 266  * ctpop32 - count the population of one bits in a 32-bit value.
 267  * @val: The value to search
 268  */
 269 static inline int ctpop32(uint32_t val)
 270 {
 271 #if QEMU_GNUC_PREREQ(3, 4)
 272     return __builtin_popcount(val);
 273 #else
 274     val = (val & 0x55555555) + ((val >>  1) & 0x55555555);
 275     val = (val & 0x33333333) + ((val >>  2) & 0x33333333);
 276     val = (val & 0x0f0f0f0f) + ((val >>  4) & 0x0f0f0f0f);
 277     val = (val & 0x00ff00ff) + ((val >>  8) & 0x00ff00ff);
 278     val = (val & 0x0000ffff) + ((val >> 16) & 0x0000ffff);
 279
 280     return val;
 281 #endif
 282 }
 283
 284 /**
 285  * ctpop64 - count the population of one bits in a 64-bit value.
 286  * @val: The value to search
 287  */
 288 static inline int ctpop64(uint64_t val)
 289 {
 290 #if QEMU_GNUC_PREREQ(3, 4)
 291     return __builtin_popcountll(val);
 292 #else
 293     val = (val & 0x5555555555555555ULL) + ((val >>  1) & 0x5555555555555555ULL);
 294     val = (val & 0x3333333333333333ULL) + ((val >>  2) & 0x3333333333333333ULL);
 295     val = (val & 0x0f0f0f0f0f0f0f0fULL) + ((val >>  4) & 0x0f0f0f0f0f0f0f0fULL);
 296     val = (val & 0x00ff00ff00ff00ffULL) + ((val >>  8) & 0x00ff00ff00ff00ffULL);
 297     val = (val & 0x0000ffff0000ffffULL) + ((val >> 16) & 0x0000ffff0000ffffULL);
 298     val = (val & 0x00000000ffffffffULL) + ((val >> 32) & 0x00000000ffffffffULL);
 299
 300     return val;
 301 #endif
 302 }
 303
 304 /* Host type specific sizes of these routines.  */
 305
 306 #if ULONG_MAX == UINT32_MAX
 307 # define clzl   clz32
 308 # define ctzl   ctz32
 309 # define clol   clo32
 310 # define ctol   cto32
 311 # define ctpopl ctpop32
 312 #elif ULONG_MAX == UINT64_MAX
 313 # define clzl   clz64
 314 # define ctzl   ctz64
 315 # define clol   clo64
 316 # define ctol   cto64
 317 # define ctpopl ctpop64
 318 #else
 319 # error Unknown sizeof long
 320 #endif
 321
 322 #endif