sysdeps/x86/tst-ifunc-isa.h

   1 /* IFUNC resolver with CPU_FEATURE_ACTIVE.
   2    Copyright (C) 2021-2022 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <sys/platform/x86.h>
  20
  21 enum isa
  22 {
  23   none,
  24   sse2,
  25   sse4_2,
  26   avx,
  27   avx2,
  28   avx512f
  29 };
  30
  31 enum isa
  32 __attribute__ ((__optimize__ ("-fno-stack-protector")))
  33 get_isa (void)
  34 {
  35   if (CPU_FEATURE_ACTIVE (AVX512F))
  36     return avx512f;
  37   if (CPU_FEATURE_ACTIVE (AVX2))
  38     return avx2;
  39   if (CPU_FEATURE_ACTIVE (AVX))
  40     return avx;
  41   if (CPU_FEATURE_ACTIVE (SSE4_2))
  42     return sse4_2;
  43   if (CPU_FEATURE_ACTIVE (SSE2))
  44     return sse2;
  45   return none;
  46 }
  47
  48 static int
  49 isa_sse2 (void)
  50 {
  51   return sse2;
  52 }
  53
  54 static int
  55 isa_sse4_2 (void)
  56 {
  57   return sse4_2;
  58 }
  59
  60 static int
  61 isa_avx (void)
  62 {
  63   return avx;
  64 }
  65
  66 static int
  67 isa_avx2 (void)
  68 {
  69   return avx2;
  70 }
  71
  72 static int
  73 isa_avx512f (void)
  74 {
  75   return avx512f;
  76 }
  77
  78 static int
  79 isa_none (void)
  80 {
  81   return none;
  82 }
  83
  84 int foo (void) __attribute__ ((ifunc ("foo_ifunc")));
  85
  86 void *
  87 __attribute__ ((__optimize__ ("-fno-stack-protector")))
  88 foo_ifunc (void)
  89 {
  90   switch (get_isa ())
  91     {
  92     case avx512f:
  93       return isa_avx512f;
  94     case avx2:
  95       return isa_avx2;
  96     case avx:
  97       return isa_avx;
  98     case sse4_2:
  99       return isa_sse4_2;
 100     case sse2:
 101       return isa_sse2;
 102     default:
 103       break;
 104     }
 105   return isa_none;
 106 }