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 /* Note that some of those functions may end up calling libgcc functions,
  27    depending on the host machine. It is up to the target emulation to
  28    cope with that. */
  29
  30 /* Binary search for leading zeros.  */
  31
  32 static always_inline int clz32(uint32_t val)
  33 {
  34     int cnt = 0;
  35
  36     if (!(val & 0xFFFF0000U)) {
  37         cnt += 16;
  38         val <<= 16;
  39     }
  40     if (!(val & 0xFF000000U)) {
  41         cnt += 8;
  42         val <<= 8;
  43     }
  44     if (!(val & 0xF0000000U)) {
  45         cnt += 4;
  46         val <<= 4;
  47     }
  48     if (!(val & 0xC0000000U)) {
  49         cnt += 2;
  50         val <<= 2;
  51     }
  52     if (!(val & 0x80000000U)) {
  53         cnt++;
  54         val <<= 1;
  55     }
  56     if (!(val & 0x80000000U)) {
  57         cnt++;
  58     }
  59     return cnt;
  60 }
  61
  62 static always_inline int clo32(uint32_t val)
  63 {
  64     return clz32(~val);
  65 }
  66
  67 static always_inline int clz64(uint64_t val)
  68 {
  69     int cnt = 0;
  70
  71     if (!(val & 0xFFFFFFFF00000000ULL)) {
  72         cnt += 32;
  73         val <<= 32;
  74     }
  75     if (!(val & 0xFFFF000000000000ULL)) {
  76         cnt += 16;
  77         val <<= 16;
  78     }
  79     if (!(val & 0xFF00000000000000ULL)) {
  80         cnt += 8;
  81         val <<= 8;
  82     }
  83     if (!(val & 0xF000000000000000ULL)) {
  84         cnt += 4;
  85         val <<= 4;
  86     }
  87     if (!(val & 0xC000000000000000ULL)) {
  88         cnt += 2;
  89         val <<= 2;
  90     }
  91     if (!(val & 0x8000000000000000ULL)) {
  92         cnt++;
  93         val <<= 1;
  94     }
  95     if (!(val & 0x8000000000000000ULL)) {
  96         cnt++;
  97     }
  98     return cnt;
  99 }
 100
 101 static always_inline int clo64(uint64_t val)
 102 {
 103     return clz64(~val);
 104 }