gcc/common/config/rs6000/rs6000-common.cc

   1 /* Common hooks for IBM RS/6000.
   2    Copyright (C) 1991-2024 Free Software Foundation, Inc.
   3
   4    This file is part of GCC.
   5
   6    GCC is free software; you can redistribute it and/or modify it
   7    under the terms of the GNU General Public License as published
   8    by the Free Software Foundation; either version 3, or (at your
   9    option) any later version.
  10
  11    GCC is distributed in the hope that it will be useful, but WITHOUT
  12    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  13    or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
  14    License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with GCC; see the file COPYING3.  If not see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #include "config.h"
  21 #include "system.h"
  22 #include "coretypes.h"
  23 #include "diagnostic-core.h"
  24 #include "tm.h"
  25 #include "common/common-target.h"
  26 #include "common/common-target-def.h"
  27 #include "opts.h"
  28 #include "flags.h"
  29
  30 /* Implement TARGET_OPTION_OPTIMIZATION_TABLE.  */
  31 static const struct default_options rs6000_option_optimization_table[] =
  32   {
  33     /* Split multi-word types early.  */
  34     { OPT_LEVELS_ALL, OPT_fsplit_wide_types_early, NULL, 1 },
  35     /* Enable -fsched-pressure for first pass instruction scheduling.  */
  36     { OPT_LEVELS_1_PLUS, OPT_fsched_pressure, NULL, 1 },
  37     /* Enable -free for zero extension and sign extension elimination.*/
  38     { OPT_LEVELS_2_PLUS, OPT_free, NULL, 1 },
  39     /* Enable -munroll-only-small-loops with -funroll-loops to unroll small
  40        loops at -O2 and above by default.  */
  41     { OPT_LEVELS_2_PLUS_SPEED_ONLY, OPT_funroll_loops, NULL, 1 },
  42     { OPT_LEVELS_2_PLUS_SPEED_ONLY, OPT_munroll_only_small_loops, NULL, 1 },
  43
  44     /* -frename-registers leads to non-optimal codegen and performance
  45        on rs6000, turn it off by default.  */
  46     { OPT_LEVELS_ALL, OPT_frename_registers, NULL, 0 },
  47
  48     /* Double growth factor to counter reduced min jump length.  */
  49     { OPT_LEVELS_ALL, OPT__param_max_grow_copy_bb_insns_, NULL, 16 },
  50     { OPT_LEVELS_NONE, 0, NULL, 0 }
  51   };
  52
  53 /* Implement TARGET_OPTION_INIT_STRUCT.  */
  54
  55 static void
  56 rs6000_option_init_struct (struct gcc_options *opts)
  57 {
  58   if (DEFAULT_ABI == ABI_DARWIN)
  59     /* The Darwin libraries never set errno, so we might as well
  60        avoid calling them when that's the only reason we would.  */
  61     opts->x_flag_errno_math = 0;
  62
  63   /* Enable section anchors by default.  */
  64   if (!TARGET_MACHO)
  65     opts->x_flag_section_anchors = 1;
  66
  67   /* By default, always emit DWARF-2 unwind info.  This allows debugging
  68      without maintaining a stack frame back-chain.  It also allows the
  69      debugger to find out where on-entry register values are stored at any
  70      point in a function, without having to analyze the executable code (which
  71      isn't even possible to do in the general case).  */
  72 #ifdef OBJECT_FORMAT_ELF
  73   opts->x_flag_asynchronous_unwind_tables = 1;
  74 #endif
  75 }
  76
  77 /* If not otherwise specified by a target, make 'long double' equivalent to
  78    'double'.  */
  79
  80 #ifndef RS6000_DEFAULT_LONG_DOUBLE_SIZE
  81 #define RS6000_DEFAULT_LONG_DOUBLE_SIZE 64
  82 #endif
  83
  84 /* Implement TARGET_HANDLE_OPTION.  */
  85
  86 static bool
  87 rs6000_handle_option (struct gcc_options *opts, struct gcc_options *opts_set,
  88                       const struct cl_decoded_option *decoded,
  89                       location_t loc)
  90 {
  91   char *p, *q;
  92   size_t code = decoded->opt_index;
  93   const char *arg = decoded->arg;
  94   int value = decoded->value;
  95
  96   switch (code)
  97     {
  98     case OPT_mfull_toc:
  99       opts->x_rs6000_isa_flags &= ~OPTION_MASK_MINIMAL_TOC;
 100       opts->x_TARGET_NO_FP_IN_TOC = 0;
 101       opts->x_TARGET_NO_SUM_IN_TOC = 0;
 102       opts_set->x_rs6000_isa_flags |= OPTION_MASK_MINIMAL_TOC;
 103 #ifdef TARGET_USES_SYSV4_OPT
 104       /* Note, V.4 no longer uses a normal TOC, so make -mfull-toc, be
 105          just the same as -mminimal-toc.  */
 106       opts->x_rs6000_isa_flags |= OPTION_MASK_MINIMAL_TOC;
 107       opts_set->x_rs6000_isa_flags |= OPTION_MASK_MINIMAL_TOC;
 108 #endif
 109       break;
 110
 111 #ifdef TARGET_USES_SYSV4_OPT
 112     case OPT_mtoc:
 113       /* Make -mtoc behave like -mminimal-toc.  */
 114       opts->x_rs6000_isa_flags |= OPTION_MASK_MINIMAL_TOC;
 115       opts_set->x_rs6000_isa_flags |= OPTION_MASK_MINIMAL_TOC;
 116       break;
 117 #endif
 118
 119 #ifdef TARGET_USES_AIX64_OPT
 120     case OPT_maix64:
 121 #else
 122     case OPT_m64:
 123 #endif
 124       opts->x_rs6000_isa_flags |= (~opts_set->x_rs6000_isa_flags
 125                                    & OPTION_MASK_PPC_GFXOPT);
 126       break;
 127
 128     case OPT_mminimal_toc:
 129       if (value == 1)
 130         {
 131           opts->x_TARGET_NO_FP_IN_TOC = 0;
 132           opts->x_TARGET_NO_SUM_IN_TOC = 0;
 133         }
 134       break;
 135
 136     case OPT_mpowerpc_gpopt:
 137     case OPT_mpowerpc_gfxopt:
 138       break;
 139
 140     case OPT_mdebug_:
 141       p = ASTRDUP (arg);
 142       opts->x_rs6000_debug = 0;
 143
 144       while ((q = strtok (p, ",")) != NULL)
 145         {
 146           unsigned mask = 0;
 147           bool invert;
 148
 149           p = NULL;
 150           if (*q == '!')
 151             {
 152               invert = true;
 153               q++;
 154             }
 155           else
 156             invert = false;
 157
 158           if (! strcmp (q, "all"))
 159             mask = MASK_DEBUG_ALL;
 160           else if (! strcmp (q, "stack"))
 161             mask = MASK_DEBUG_STACK;
 162           else if (! strcmp (q, "arg"))
 163             mask = MASK_DEBUG_ARG;
 164           else if (! strcmp (q, "reg"))
 165             mask = MASK_DEBUG_REG;
 166           else if (! strcmp (q, "addr"))
 167             mask = MASK_DEBUG_ADDR;
 168           else if (! strcmp (q, "cost"))
 169             mask = MASK_DEBUG_COST;
 170           else if (! strcmp (q, "target"))
 171             mask = MASK_DEBUG_TARGET;
 172           else if (! strcmp (q, "builtin"))
 173             mask = MASK_DEBUG_BUILTIN;
 174           else
 175             error_at (loc, "unknown %<-mdebug-%s%> switch", q);
 176
 177           if (invert)
 178             opts->x_rs6000_debug &= ~mask;
 179           else
 180             opts->x_rs6000_debug |= mask;
 181         }
 182       break;
 183
 184 #ifdef TARGET_USES_SYSV4_OPT
 185     case OPT_mrelocatable:
 186       if (value == 1)
 187         {
 188           opts->x_rs6000_isa_flags |= OPTION_MASK_MINIMAL_TOC;
 189           opts_set->x_rs6000_isa_flags |= OPTION_MASK_MINIMAL_TOC;
 190           opts->x_TARGET_NO_FP_IN_TOC = 1;
 191         }
 192       break;
 193
 194     case OPT_mrelocatable_lib:
 195       if (value == 1)
 196         {
 197           opts->x_rs6000_isa_flags |= (OPTION_MASK_RELOCATABLE
 198                                        | OPTION_MASK_MINIMAL_TOC);
 199           opts_set->x_rs6000_isa_flags |= (OPTION_MASK_RELOCATABLE
 200                                            | OPTION_MASK_MINIMAL_TOC);
 201           opts->x_TARGET_NO_FP_IN_TOC = 1;
 202         }
 203       else
 204         {
 205           opts->x_rs6000_isa_flags &= ~OPTION_MASK_RELOCATABLE;
 206           opts_set->x_rs6000_isa_flags |= OPTION_MASK_RELOCATABLE;
 207         }
 208       break;
 209 #endif
 210
 211     case OPT_mlong_double_:
 212       if (value != 64 && value != 128)
 213         {
 214           error_at (loc, "unknown switch %<-mlong-double-%s%>", arg);
 215           opts->x_rs6000_long_double_type_size
 216             = RS6000_DEFAULT_LONG_DOUBLE_SIZE;
 217           return false;
 218         }
 219       break;
 220
 221     case OPT_mabi_ibmlongdouble:
 222     case OPT_mabi_ieeelongdouble:
 223       if (opts->x_rs6000_long_double_type_size == 64)
 224         {
 225           error_at (loc, "option %<%s%> requires %<-mlong-double-128%>",
 226                     decoded->orig_option_with_args_text);
 227           return true;
 228         }
 229       break;
 230
 231     case OPT_mrecip:
 232       opts->x_rs6000_recip_name = (value) ? "default" : "none";
 233       break;
 234     }
 235   return true;
 236 }
 237
 238 /* -fsplit-stack uses a field in the TCB, available with glibc-2.19.
 239    We also allow 2.18 because alignment padding guarantees that the
 240    space is available there too.  */
 241
 242 static bool
 243 rs6000_supports_split_stack (bool report,
 244                              struct gcc_options *opts ATTRIBUTE_UNUSED)
 245 {
 246 #ifndef TARGET_GLIBC_MAJOR
 247 #define TARGET_GLIBC_MAJOR 0
 248 #endif
 249 #ifndef TARGET_GLIBC_MINOR
 250 #define TARGET_GLIBC_MINOR 0
 251 #endif
 252   /* Note: Can't test DEFAULT_ABI here, it isn't set until later.  */
 253   if (TARGET_GLIBC_MAJOR * 1000 + TARGET_GLIBC_MINOR >= 2018
 254       && TARGET_64BIT
 255       && TARGET_ELF)
 256     return true;
 257
 258   if (report)
 259     error ("%<-fsplit-stack%> currently only supported on PowerPC64 GNU/Linux with glibc-2.18 or later");
 260   return false;
 261 }
 262
 263 #undef TARGET_HANDLE_OPTION
 264 #define TARGET_HANDLE_OPTION rs6000_handle_option
 265
 266 #undef TARGET_OPTION_INIT_STRUCT
 267 #define TARGET_OPTION_INIT_STRUCT rs6000_option_init_struct
 268
 269 #undef TARGET_OPTION_OPTIMIZATION_TABLE
 270 #define TARGET_OPTION_OPTIMIZATION_TABLE rs6000_option_optimization_table
 271
 272 #undef TARGET_SUPPORTS_SPLIT_STACK
 273 #define TARGET_SUPPORTS_SPLIT_STACK rs6000_supports_split_stack
 274
 275 struct gcc_targetm_common targetm_common = TARGETM_COMMON_INITIALIZER;