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
  26 #if defined(__x86_64__)
  27 #define __HAVE_FAST_MULU64__
  28 static always_inline void mulu64 (uint64_t *plow, uint64_t *phigh,
  29                                   uint64_t a, uint64_t b)
  30 {
  31     __asm__ ("mul %0\n\t"
  32              : "=d" (*phigh), "=a" (*plow)
  33              : "a" (a), "0" (b));
  34 }
  35 #define __HAVE_FAST_MULS64__
  36 static always_inline void muls64 (uint64_t *plow, uint64_t *phigh,
  37                                   int64_t a, int64_t b)
  38 {
  39     __asm__ ("imul %0\n\t"
  40              : "=d" (*phigh), "=a" (*plow)
  41              : "a" (a), "0" (b));
  42 }
  43 #else
  44 void muls64(uint64_t *phigh, uint64_t *plow, int64_t a, int64_t b);
  45 void mulu64(uint64_t *phigh, uint64_t *plow, uint64_t a, uint64_t b);
  46 #endif
  47
  48 /* Note that some of those functions may end up calling libgcc functions,
  49    depending on the host machine. It is up to the target emulation to
  50    cope with that. */
  51
  52 /* Binary search for leading zeros.  */
  53
  54 static always_inline int clz32(uint32_t val)
  55 {
  56     int cnt = 0;
  57
  58     if (!(val & 0xFFFF0000U)) {
  59         cnt += 16;
  60         val <<= 16;
  61     }
  62     if (!(val & 0xFF000000U)) {
  63         cnt += 8;
  64         val <<= 8;
  65     }
  66     if (!(val & 0xF0000000U)) {
  67         cnt += 4;
  68         val <<= 4;
  69     }
  70     if (!(val & 0xC0000000U)) {
  71         cnt += 2;
  72         val <<= 2;
  73     }
  74     if (!(val & 0x80000000U)) {
  75         cnt++;
  76         val <<= 1;
  77     }
  78     if (!(val & 0x80000000U)) {
  79         cnt++;
  80     }
  81     return cnt;
  82 }
  83
  84 static always_inline int clo32(uint32_t val)
  85 {
  86     return clz32(~val);
  87 }
  88
  89 static always_inline int clz64(uint64_t val)
  90 {
  91     int cnt = 0;
  92
  93     if (!(val >> 32)) {
  94         cnt += 32;
  95     } else {
  96         val >>= 32;
  97     }
  98
  99     return cnt + clz32(val);
 100 }
 101
 102 static always_inline int clo64(uint64_t val)
 103 {
 104     return clz64(~val);
 105 }
 106
 107 static always_inline int ctz32 (uint32_t val)
 108 {
 109     int cnt;
 110
 111     cnt = 0;
 112     if (!(val & 0x0000FFFFUL)) {
 113          cnt += 16;
 114         val >>= 16;
 115      }
 116     if (!(val & 0x000000FFUL)) {
 117          cnt += 8;
 118         val >>= 8;
 119      }
 120     if (!(val & 0x0000000FUL)) {
 121          cnt += 4;
 122         val >>= 4;
 123      }
 124     if (!(val & 0x00000003UL)) {
 125          cnt += 2;
 126         val >>= 2;
 127      }
 128     if (!(val & 0x00000001UL)) {
 129          cnt++;
 130         val >>= 1;
 131      }
 132     if (!(val & 0x00000001UL)) {
 133          cnt++;
 134      }
 135
 136      return cnt;
 137  }
 138
 139 static always_inline int cto32 (uint32_t val)
 140  {
 141     return ctz32(~val);
 142 }
 143
 144 static always_inline int ctz64 (uint64_t val)
 145 {
 146     int cnt;
 147
 148     cnt = 0;
 149     if (!((uint32_t)val)) {
 150         cnt += 32;
 151         val >>= 32;
 152     }
 153
 154     return cnt + ctz32(val);
 155 }
 156
 157 static always_inline int cto64 (uint64_t val)
 158 {
 159     return ctz64(~val);
 160 }
 161
 162 static always_inline int ctpop8 (uint8_t val)
 163 {
 164     val = (val & 0x55) + ((val >> 1) & 0x55);
 165     val = (val & 0x33) + ((val >> 2) & 0x33);
 166     val = (val & 0x0f) + ((val >> 4) & 0x0f);
 167
 168     return val;
 169 }
 170
 171 static always_inline int ctpop16 (uint16_t val)
 172 {
 173     val = (val & 0x5555) + ((val >> 1) & 0x5555);
 174     val = (val & 0x3333) + ((val >> 2) & 0x3333);
 175     val = (val & 0x0f0f) + ((val >> 4) & 0x0f0f);
 176     val = (val & 0x00ff) + ((val >> 8) & 0x00ff);
 177
 178     return val;
 179 }
 180
 181 static always_inline int ctpop32 (uint32_t val)
 182 {
 183     val = (val & 0x55555555) + ((val >>  1) & 0x55555555);
 184     val = (val & 0x33333333) + ((val >>  2) & 0x33333333);
 185     val = (val & 0x0f0f0f0f) + ((val >>  4) & 0x0f0f0f0f);
 186     val = (val & 0x00ff00ff) + ((val >>  8) & 0x00ff00ff);
 187     val = (val & 0x0000ffff) + ((val >> 16) & 0x0000ffff);
 188
 189     return val;
 190 }
 191
 192 static always_inline int ctpop64 (uint64_t val)
 193 {
 194     val = (val & 0x5555555555555555ULL) + ((val >>  1) & 0x5555555555555555ULL);
 195     val = (val & 0x3333333333333333ULL) + ((val >>  2) & 0x3333333333333333ULL);
 196     val = (val & 0x0f0f0f0f0f0f0f0fULL) + ((val >>  4) & 0x0f0f0f0f0f0f0f0fULL);
 197     val = (val & 0x00ff00ff00ff00ffULL) + ((val >>  8) & 0x00ff00ff00ff00ffULL);
 198     val = (val & 0x0000ffff0000ffffULL) + ((val >> 16) & 0x0000ffff0000ffffULL);
 199     val = (val & 0x00000000ffffffffULL) + ((val >> 32) & 0x00000000ffffffffULL);
 200
 201     return val;
 202 }