gcc/config/rs6000/linux.h

   1 /* Definitions of target machine for GNU compiler,
   2    for PowerPC machines running Linux.
   3    Copyright (C) 1996-2018 Free Software Foundation, Inc.
   4    Contributed by Michael Meissner (meissner@cygnus.com).
   5
   6    This file is part of GCC.
   7
   8    GCC is free software; you can redistribute it and/or modify it
   9    under the terms of the GNU General Public License as published
  10    by the Free Software Foundation; either version 3, or (at your
  11    option) any later version.
  12
  13    GCC is distributed in the hope that it will be useful, but WITHOUT
  14    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  15    or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
  16    License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with GCC; see the file COPYING3.  If not see
  20    <http://www.gnu.org/licenses/>.  */
  21
  22 /* Linux doesn't support saving and restoring 64-bit regs in a 32-bit
  23    process.  */
  24 #define OS_MISSING_POWERPC64 1
  25
  26 /* We use glibc _mcount for profiling.  */
  27 #define NO_PROFILE_COUNTERS 1
  28
  29 #ifdef SINGLE_LIBC
  30 #define OPTION_GLIBC  (DEFAULT_LIBC == LIBC_GLIBC)
  31 #define OPTION_UCLIBC (DEFAULT_LIBC == LIBC_UCLIBC)
  32 #define OPTION_BIONIC (DEFAULT_LIBC == LIBC_BIONIC)
  33 #undef OPTION_MUSL
  34 #define OPTION_MUSL   (DEFAULT_LIBC == LIBC_MUSL)
  35 #else
  36 #define OPTION_GLIBC  (linux_libc == LIBC_GLIBC)
  37 #define OPTION_UCLIBC (linux_libc == LIBC_UCLIBC)
  38 #define OPTION_BIONIC (linux_libc == LIBC_BIONIC)
  39 #undef OPTION_MUSL
  40 #define OPTION_MUSL   (linux_libc == LIBC_MUSL)
  41 #endif
  42
  43 /* Determine what functions are present at the runtime;
  44    this includes full c99 runtime and sincos.  */
  45 #undef TARGET_LIBC_HAS_FUNCTION
  46 #define TARGET_LIBC_HAS_FUNCTION linux_libc_has_function
  47
  48 #undef  TARGET_OS_CPP_BUILTINS
  49 #define TARGET_OS_CPP_BUILTINS()                \
  50   do                                            \
  51     {                                           \
  52       builtin_define_std ("PPC");               \
  53       builtin_define_std ("powerpc");           \
  54       builtin_assert ("cpu=powerpc");           \
  55       builtin_assert ("machine=powerpc");       \
  56       TARGET_OS_SYSV_CPP_BUILTINS ();           \
  57     }                                           \
  58   while (0)
  59
  60 #undef  CPP_OS_DEFAULT_SPEC
  61 #define CPP_OS_DEFAULT_SPEC "%(cpp_os_linux)"
  62
  63 #undef  LINK_SHLIB_SPEC
  64 #define LINK_SHLIB_SPEC "%{shared:-shared} %{!shared: %{static:-static}} \
  65   %{static-pie:-static -pie --no-dynamic-linker -z text}"
  66
  67 #undef  LIB_DEFAULT_SPEC
  68 #define LIB_DEFAULT_SPEC "%(lib_linux)"
  69
  70 #undef  STARTFILE_DEFAULT_SPEC
  71 #define STARTFILE_DEFAULT_SPEC "%(startfile_linux)"
  72
  73 #undef  ENDFILE_DEFAULT_SPEC
  74 #define ENDFILE_DEFAULT_SPEC "%(endfile_linux)"
  75
  76 #undef  LINK_START_DEFAULT_SPEC
  77 #define LINK_START_DEFAULT_SPEC "%(link_start_linux)"
  78
  79 #undef  LINK_OS_DEFAULT_SPEC
  80 #define LINK_OS_DEFAULT_SPEC "%(link_os_linux)"
  81
  82 #undef  DEFAULT_ASM_ENDIAN
  83 #if (TARGET_DEFAULT & MASK_LITTLE_ENDIAN)
  84 #define DEFAULT_ASM_ENDIAN " -mlittle"
  85 #define LINK_OS_LINUX_EMUL ENDIAN_SELECT(" -m elf32ppclinux",   \
  86                                          " -m elf32lppclinux",  \
  87                                          " -m elf32lppclinux")
  88 #else
  89 #define DEFAULT_ASM_ENDIAN " -mbig"
  90 #define LINK_OS_LINUX_EMUL ENDIAN_SELECT(" -m elf32ppclinux",   \
  91                                          " -m elf32lppclinux",  \
  92                                          " -m elf32ppclinux")
  93 #endif
  94
  95 #undef LINK_OS_LINUX_SPEC
  96 #define LINK_OS_LINUX_SPEC LINK_OS_LINUX_EMUL " %{!shared: %{!static: \
  97   %{!static-pie: \
  98     %{rdynamic:-export-dynamic} \
  99     -dynamic-linker " GNU_USER_DYNAMIC_LINKER "}}}"
 100
 101 /* For backward compatibility, we must continue to use the AIX
 102    structure return convention.  */
 103 #undef  DRAFT_V4_STRUCT_RET
 104 #define DRAFT_V4_STRUCT_RET 1
 105
 106 /* We are 32-bit all the time, so optimize a little.  */
 107 #undef TARGET_64BIT
 108 #define TARGET_64BIT 0
 109
 110 /* We don't need to generate entries in .fixup, except when
 111    -mrelocatable or -mrelocatable-lib is given.  */
 112 #undef RELOCATABLE_NEEDS_FIXUP
 113 #define RELOCATABLE_NEEDS_FIXUP \
 114   (rs6000_isa_flags & rs6000_isa_flags_explicit & OPTION_MASK_RELOCATABLE)
 115
 116 #ifdef TARGET_LIBC_PROVIDES_SSP
 117 /* ppc32 glibc provides __stack_chk_guard in -0x7008(2).  */
 118 #define TARGET_THREAD_SSP_OFFSET        -0x7008
 119 #endif
 120
 121 #define POWERPC_LINUX
 122
 123 /* ppc linux has 128-bit long double support in glibc 2.4 and later.  */
 124 #ifdef TARGET_DEFAULT_LONG_DOUBLE_128
 125 #define RS6000_DEFAULT_LONG_DOUBLE_SIZE 128
 126 #endif
 127
 128 /* Static stack checking is supported by means of probes.  */
 129 #define STACK_CHECK_STATIC_BUILTIN 1
 130
 131 /* Software floating point support for exceptions and rounding modes
 132    depends on the C library in use.  */
 133 #undef TARGET_FLOAT_EXCEPTIONS_ROUNDING_SUPPORTED_P
 134 #define TARGET_FLOAT_EXCEPTIONS_ROUNDING_SUPPORTED_P \
 135   rs6000_linux_float_exceptions_rounding_supported_p
 136
 137 /* Support for TARGET_ATOMIC_ASSIGN_EXPAND_FENV without FPRs depends
 138    on glibc 2.19 or greater.  */
 139 #if TARGET_GLIBC_MAJOR > 2 \
 140   || (TARGET_GLIBC_MAJOR == 2 && TARGET_GLIBC_MINOR >= 19)
 141 #define RS6000_GLIBC_ATOMIC_FENV 1
 142 #endif