sysdeps/s390/multiarch/ifunc-resolve.h

   1 /* IFUNC resolver function for CPU specific functions.
   2    32/64 bit S/390 version.
   3    Copyright (C) 2015 Free Software Foundation, Inc.
   4    This file is part of the GNU C Library.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #include <unistd.h>
  21 #include <dl-procinfo.h>
  22
  23 #define S390_STFLE_BITS_Z10  34 /* General instructions extension */
  24 #define S390_STFLE_BITS_Z196 45 /* Distinct operands, pop ... */
  25
  26 #define S390_IS_Z196(STFLE_BITS)                        \
  27   ((STFLE_BITS & (1ULL << (63 - S390_STFLE_BITS_Z196))) != 0)
  28
  29 #define S390_IS_Z10(STFLE_BITS)                         \
  30   ((STFLE_BITS & (1ULL << (63 - S390_STFLE_BITS_Z10))) != 0)
  31
  32 #define S390_STORE_STFLE(STFLE_BITS)                                    \
  33   /* We want just 1 double word to be returned.  */                     \
  34   register unsigned long reg0 asm("0") = 0;                             \
  35                                                                         \
  36   asm volatile(".machine push"        "\n\t"                            \
  37                ".machine \"z9-109\""  "\n\t"                            \
  38                ".machinemode \"zarch_nohighgprs\"\n\t"                  \
  39                "stfle %0"             "\n\t"                            \
  40                ".machine pop"         "\n"                              \
  41                : "=QS" (STFLE_BITS), "+d" (reg0)                        \
  42                : : "cc");
  43
  44 #define s390_libc_ifunc(FUNC)                                           \
  45   asm (".globl " #FUNC "\n\t"                                           \
  46        ".type  " #FUNC ",@gnu_indirect_function\n\t"                    \
  47        ".set   " #FUNC ",__resolve_" #FUNC "\n\t"                       \
  48        ".globl __GI_" #FUNC "\n\t"                                      \
  49        ".set   __GI_" #FUNC "," #FUNC "\n");                            \
  50                                                                         \
  51   /* Make the declarations of the optimized functions hidden in order
  52      to prevent GOT slots being generated for them. */                  \
  53   extern void *__##FUNC##_z196 attribute_hidden;                        \
  54   extern void *__##FUNC##_z10 attribute_hidden;                         \
  55   extern void *__##FUNC##_default attribute_hidden;                     \
  56                                                                         \
  57   void *__resolve_##FUNC (unsigned long int dl_hwcap)                   \
  58   {                                                                     \
  59     if ((dl_hwcap & HWCAP_S390_STFLE)                                   \
  60         && (dl_hwcap & HWCAP_S390_ZARCH)                                \
  61         && (dl_hwcap & HWCAP_S390_HIGH_GPRS))                           \
  62       {                                                                 \
  63         unsigned long long stfle_bits;                                  \
  64         S390_STORE_STFLE (stfle_bits);                                  \
  65                                                                         \
  66         if (S390_IS_Z196 (stfle_bits))                                  \
  67           return &__##FUNC##_z196;                                      \
  68         else if (S390_IS_Z10 (stfle_bits))                              \
  69           return &__##FUNC##_z10;                                       \
  70         else                                                            \
  71           return &__##FUNC##_default;                                   \
  72       }                                                                 \
  73     else                                                                \
  74       return &__##FUNC##_default;                                       \
  75   }
  76
  77 #define s390_vx_libc_ifunc(FUNC)                \
  78   s390_vx_libc_ifunc2(FUNC, FUNC)
  79
  80 #define s390_vx_libc_ifunc2(RESOLVERFUNC, FUNC)                         \
  81   /* Make the declarations of the optimized functions hidden in order
  82      to prevent GOT slots being generated for them.  */                 \
  83   extern __typeof (FUNC) RESOLVERFUNC##_vx attribute_hidden;            \
  84   extern __typeof (FUNC) RESOLVERFUNC##_c attribute_hidden;             \
  85   extern void *__resolve_##RESOLVERFUNC (unsigned long int) __asm__ (#FUNC); \
  86                                                                         \
  87   void *__resolve_##RESOLVERFUNC (unsigned long int dl_hwcap)           \
  88   {                                                                     \
  89     if (dl_hwcap & HWCAP_S390_VX)                                       \
  90       return &RESOLVERFUNC##_vx;                                        \
  91     else                                                                \
  92       return &RESOLVERFUNC##_c;                                         \
  93   }                                                                     \
  94  __asm__ (".type " #FUNC ", %gnu_indirect_function");