coregrind/m_compiler.c

   1 /* -*- mode: C; c-basic-offset: 3; -*- */
   2
   3 /*--------------------------------------------------------------------*/
   4 /*--- Compiler specific stuff.                        m_compiler.c ---*/
   5 /*--------------------------------------------------------------------*/
   6
   7 /*
   8    This file is part of Valgrind, a dynamic binary instrumentation
   9    framework.
  10
  11    Copyright (C) 2014-2014 Florian Krohm
  12       florian@eich-krohm.de
  13
  14    This program is free software; you can redistribute it and/or
  15    modify it under the terms of the GNU General Public License as
  16    published by the Free Software Foundation; either version 2 of the
  17    License, or (at your option) any later version.
  18
  19    This program is distributed in the hope that it will be useful, but
  20    WITHOUT ANY WARRANTY; without even the implied warranty of
  21    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  22    General Public License for more details.
  23
  24    You should have received a copy of the GNU General Public License
  25    along with this program; if not, write to the Free Software
  26    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  27    02111-1307, USA.
  28
  29    The GNU General Public License is contained in the file COPYING.
  30 */
  31
  32 /* Currently, this file provides definitions for builtins that not all
  33    compilers or compiler versions provide.
  34
  35    Missing builtins are rare. Therefore, no attempt has been made to
  36    provide efficient implementations.
  37  */
  38
  39 #include "config.h"
  40 #include "pub_core_basics.h"
  41 #include "pub_core_libcbase.h"
  42
  43 #ifndef HAVE_BUILTIN_POPCOUT
  44
  45 /* From the GCC documentation:
  46    Returns the number of 1-bits in x. */
  47
  48 UInt
  49 __builtin_popcount(UInt x)
  50 {
  51    UInt i, count = 0;
  52
  53    for (i = 0; i < 32; ++i) {
  54       count += x & 1;
  55       x >>= 1;
  56    }
  57    return count;
  58 }
  59
  60 UInt
  61 __builtin_popcountll(ULong x)
  62 {
  63    UInt i, count = 0;
  64
  65    for (i = 0; i < 64; ++i) {
  66       count += x & 1;
  67       x >>= 1;
  68    }
  69    return count;
  70 }
  71 #endif
  72
  73 #ifndef HAVE_BUILTIN_CLZ
  74
  75 /* From the GCC documentation:
  76    Returns the number of leading 0-bits in x, starting at the most
  77    significant position. If x is 0, the result is undefined. */
  78
  79 UInt
  80 __builtin_clz(UInt x)
  81 {
  82    UInt count = 32;
  83    UInt y;
  84
  85    y = x >> 16; if (y != 0) { count -= 16; x = y; }
  86    y = x >> 8;  if (y != 0) { count -= 8;  x = y; }
  87    y = x >> 4;  if (y != 0) { count -= 4;  x = y; }
  88    y = x >> 2;  if (y != 0) { count -= 2;  x = y; }
  89    y = x >> 1;  if (y != 0) return count - 2;
  90    return count - x;
  91 }
  92
  93 UInt
  94 __builtin_clzll(ULong x)
  95 {
  96    UInt count = 64;
  97    ULong y;
  98
  99    y = x >> 32; if (y != 0) { count -= 32; x = y; }
 100    y = x >> 16; if (y != 0) { count -= 16; x = y; }
 101    y = x >> 8;  if (y != 0) { count -= 8;  x = y; }
 102    y = x >> 4;  if (y != 0) { count -= 4;  x = y; }
 103    y = x >> 2;  if (y != 0) { count -= 2;  x = y; }
 104    y = x >> 1;  if (y != 0) return count - 2;
 105    return count - x;
 106 }
 107 #endif
 108
 109 #ifndef HAVE_BUILTIN_CTZ
 110
 111 /* From the GCC documentation:
 112    Returns the number of trailing 0-bits in x, starting at the least
 113    significant bit position. If x is 0, the result is undefined. */
 114
 115 UInt
 116 __builtin_ctz(UInt x)
 117 {
 118    UInt i, count = 0;
 119
 120    for (i = 0; i < 32; ++i) {
 121       if (x & 1) break;
 122       ++count;
 123       x >>= 1;
 124    }
 125    return count;
 126 }
 127
 128 UInt
 129 __builtin_ctzll(ULong x)
 130 {
 131    UInt i, count = 0;
 132
 133    for (i = 0; i < 64; ++i) {
 134       if (x & 1) break;
 135       ++count;
 136       x >>= 1;
 137    }
 138    return count;
 139 }
 140 #endif
 141
 142
 143 #ifdef __INTEL_COMPILER
 144
 145 /* Provide certain functions Intel's ICC compiler expects to be defined. */
 146
 147 void *
 148 _intel_fast_memcpy(void *dest, const void *src, SizeT sz)
 149 {
 150    return VG_(memcpy)( dest, src, sz );
 151 }
 152
 153 void *
 154 _intel_fast_memset(void *dest, int value, SizeT num)
 155 {
 156    return VG_(memset)( dest, value, num );
 157 }
 158 #endif
 159
 160 /*--------------------------------------------------------------------*/
 161 /*--- end                                                          ---*/
 162 /*--------------------------------------------------------------------*/
 163