This file is indexed.

/usr/share/aclocal/ax_ext.m4 is in autoconf-archive 20131101-1.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
# ===========================================================================
#          http://www.gnu.org/software/autoconf-archive/ax_ext.html
# ===========================================================================
#
# SYNOPSIS
#
#   AX_EXT
#
# DESCRIPTION
#
#   Find supported SIMD extensions by requesting cpuid. When an SIMD
#   extension is found, the -m"simdextensionname" is added to SIMD_FLAGS if
#   compiler supports it. For example, if "sse2" is available, then "-msse2"
#   is added to SIMD_FLAGS.
#
#   This macro calls:
#
#     AC_SUBST(SIMD_FLAGS)
#
#   And defines:
#
#     HAVE_MMX / HAVE_SSE / HAVE_SSE2 / HAVE_SSE3 / HAVE_SSSE3 / HAVE_SSE4.1 / HAVE_SSE4.2 / HAVE_AVX
#
# LICENSE
#
#   Copyright (c) 2007 Christophe Tournayre <turn3r@users.sourceforge.net>
#   Copyright (c) 2013 Michael Petch <mpetch@capp-sysware.com>
#
#   Copying and distribution of this file, with or without modification, are
#   permitted in any medium without royalty provided the copyright notice
#   and this notice are preserved. This file is offered as-is, without any
#   warranty.

#serial 12

AC_DEFUN([AX_EXT],
[
  AC_REQUIRE([AC_CANONICAL_HOST])

  case $host_cpu in
    powerpc*)
      AC_CACHE_CHECK([whether altivec is supported], [ax_cv_have_altivec_ext],
          [
            if test `/usr/sbin/sysctl -a 2>/dev/null| grep -c hw.optional.altivec` != 0; then
                if test `/usr/sbin/sysctl -n hw.optional.altivec` = 1; then
                  ax_cv_have_altivec_ext=yes
                fi
            fi
          ])

          if test "$ax_cv_have_altivec_ext" = yes; then
            AC_DEFINE(HAVE_ALTIVEC,,[Support Altivec instructions])
            AX_CHECK_COMPILE_FLAG(-faltivec, SIMD_FLAGS="$SIMD_FLAGS -faltivec", [])
          fi
    ;;


    i[[3456]]86*|x86_64*|amd64*)

      AC_REQUIRE([AX_GCC_X86_CPUID])
      AC_REQUIRE([AX_GCC_X86_AVX_XGETBV])

      AX_GCC_X86_CPUID(0x00000001)
      ecx=`echo $ax_cv_gcc_x86_cpuid_0x00000001 | cut -d ":" -f 3`
      edx=`echo $ax_cv_gcc_x86_cpuid_0x00000001 | cut -d ":" -f 4`

      AC_CACHE_CHECK([whether mmx is supported], [ax_cv_have_mmx_ext],
      [
        ax_cv_have_mmx_ext=no
        if test "$((0x$edx>>23&0x01))" = 1; then
          ax_cv_have_mmx_ext=yes
        fi
      ])

      AC_CACHE_CHECK([whether sse is supported], [ax_cv_have_sse_ext],
      [
        ax_cv_have_sse_ext=no
        if test "$((0x$edx>>25&0x01))" = 1; then
          ax_cv_have_sse_ext=yes
        fi
      ])

      AC_CACHE_CHECK([whether sse2 is supported], [ax_cv_have_sse2_ext],
      [
        ax_cv_have_sse2_ext=no
        if test "$((0x$edx>>26&0x01))" = 1; then
          ax_cv_have_sse2_ext=yes
        fi
      ])

      AC_CACHE_CHECK([whether sse3 is supported], [ax_cv_have_sse3_ext],
      [
        ax_cv_have_sse3_ext=no
        if test "$((0x$ecx&0x01))" = 1; then
          ax_cv_have_sse3_ext=yes
        fi
      ])

      AC_CACHE_CHECK([whether ssse3 is supported], [ax_cv_have_ssse3_ext],
      [
        ax_cv_have_ssse3_ext=no
        if test "$((0x$ecx>>9&0x01))" = 1; then
          ax_cv_have_ssse3_ext=yes
        fi
      ])

      AC_CACHE_CHECK([whether sse4.1 is supported], [ax_cv_have_sse41_ext],
      [
        ax_cv_have_sse41_ext=no
        if test "$((0x$ecx>>19&0x01))" = 1; then
          ax_cv_have_sse41_ext=yes
        fi
      ])

      AC_CACHE_CHECK([whether sse4.2 is supported], [ax_cv_have_sse42_ext],
      [
        ax_cv_have_sse42_ext=no
        if test "$((0x$ecx>>20&0x01))" = 1; then
          ax_cv_have_sse42_ext=yes
        fi
      ])

      AC_CACHE_CHECK([whether avx is supported by processor], [ax_cv_have_avx_cpu_ext],
      [
        ax_cv_have_avx_cpu_ext=no
        if test "$((0x$ecx>>28&0x01))" = 1; then
          ax_cv_have_avx_cpu_ext=yes
        fi
      ])

      if test x"$ax_cv_have_avx_cpu_ext" = x"yes"; then
        AX_GCC_X86_AVX_XGETBV(0x00000000)

        xgetbv_eax="0"
        if test x"$ax_cv_gcc_x86_avx_xgetbv_0x00000000" != x"unknown"; then
          xgetbv_eax=`echo $ax_cv_gcc_x86_avx_xgetbv_0x00000000 | cut -d ":" -f 1`
        fi

        AC_CACHE_CHECK([whether avx is supported by operating system], [ax_cv_have_avx_ext],
        [
          ax_cv_have_avx_ext=no

          if test "$((0x$ecx>>27&0x01))" = 1; then
            if test "$((0x$xgetbv_eax&0x6))" = 6; then
              ax_cv_have_avx_ext=yes
            fi
          fi
        ])
        if test x"$ax_cv_have_avx_ext" = x"no"; then
          AC_MSG_WARN([Your processor supports AVX, but your operating system doesn't])
        fi
      fi

      if test "$ax_cv_have_mmx_ext" = yes; then
        AX_CHECK_COMPILE_FLAG(-mmmx, ax_cv_support_mmx_ext=yes, [])
        if test x"$ax_cv_support_mmx_ext" = x"yes"; then
          SIMD_FLAGS="$SIMD_FLAGS -mmmx"
          AC_DEFINE(HAVE_MMX,,[Support mmx instructions])
        else
          AC_MSG_WARN([Your processor supports mmx instructions but not your compiler, can you try another compiler?])
        fi
      fi

      if test "$ax_cv_have_sse_ext" = yes; then
        AX_CHECK_COMPILE_FLAG(-msse, ax_cv_support_sse_ext=yes, [])
        if test x"$ax_cv_support_sse_ext" = x"yes"; then
          SIMD_FLAGS="$SIMD_FLAGS -msse"
          AC_DEFINE(HAVE_SSE,,[Support SSE (Streaming SIMD Extensions) instructions])
        else
          AC_MSG_WARN([Your processor supports sse instructions but not your compiler, can you try another compiler?])
        fi
      fi

      if test "$ax_cv_have_sse2_ext" = yes; then
        AX_CHECK_COMPILE_FLAG(-msse2, ax_cv_support_sse2_ext=yes, [])
        if test x"$ax_cv_support_sse2_ext" = x"yes"; then
          SIMD_FLAGS="$SIMD_FLAGS -msse2"
          AC_DEFINE(HAVE_SSE2,,[Support SSE2 (Streaming SIMD Extensions 2) instructions])
        else
          AC_MSG_WARN([Your processor supports sse2 instructions but not your compiler, can you try another compiler?])
        fi
      fi

      if test "$ax_cv_have_sse3_ext" = yes; then
        AX_CHECK_COMPILE_FLAG(-msse3, ax_cv_support_sse3_ext=yes, [])
        if test x"$ax_cv_support_sse3_ext" = x"yes"; then
          SIMD_FLAGS="$SIMD_FLAGS -msse3"
          AC_DEFINE(HAVE_SSE3,,[Support SSE3 (Streaming SIMD Extensions 3) instructions])
        else
          AC_MSG_WARN([Your processor supports sse3 instructions but not your compiler, can you try another compiler?])
        fi
      fi

      if test "$ax_cv_have_ssse3_ext" = yes; then
        AX_CHECK_COMPILE_FLAG(-mssse3, ax_cv_support_ssse3_ext=yes, [])
        if test x"$ax_cv_support_ssse3_ext" = x"yes"; then
          SIMD_FLAGS="$SIMD_FLAGS -mssse3"
          AC_DEFINE(HAVE_SSSE3,,[Support SSSE3 (Supplemental Streaming SIMD Extensions 3) instructions])
        else
          AC_MSG_WARN([Your processor supports ssse3 instructions but not your compiler, can you try another compiler?])
        fi
      fi

      if test "$ax_cv_have_sse41_ext" = yes; then
        AX_CHECK_COMPILE_FLAG(-msse4.1, ax_cv_support_sse41_ext=yes, [])
        if test x"$ax_cv_support_sse41_ext" = x"yes"; then
          SIMD_FLAGS="$SIMD_FLAGS -msse4.1"
          AC_DEFINE(HAVE_SSE4_1,,[Support SSSE4.1 (Streaming SIMD Extensions 4.1) instructions])
        else
          AC_MSG_WARN([Your processor supports sse4.1 instructions but not your compiler, can you try another compiler?])
        fi
      fi

      if test "$ax_cv_have_sse42_ext" = yes; then
        AX_CHECK_COMPILE_FLAG(-msse4.2, ax_cv_support_sse42_ext=yes, [])
        if test x"$ax_cv_support_sse42_ext" = x"yes"; then
          SIMD_FLAGS="$SIMD_FLAGS -msse4.2"
          AC_DEFINE(HAVE_SSE4_2,,[Support SSSE4.2 (Streaming SIMD Extensions 4.2) instructions])
        else
          AC_MSG_WARN([Your processor supports sse4.2 instructions but not your compiler, can you try another compiler?])
        fi
      fi

      if test "$ax_cv_have_avx_ext" = yes; then
        AX_CHECK_COMPILE_FLAG(-mavx, ax_cv_support_avx_ext=yes, [])
        if test x"$ax_cv_support_avx_ext" = x"yes"; then
          SIMD_FLAGS="$SIMD_FLAGS -mavx"
          AC_DEFINE(HAVE_AVX,,[Support AVX (Advanced Vector Extensions) instructions])
        else
          AC_MSG_WARN([Your processor supports avx instructions but not your compiler, can you try another compiler?])
        fi
      fi

  ;;
  esac

  AC_SUBST(SIMD_FLAGS)
])