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

   1 /* Common hooks for IBM RS/6000.
   2    Copyright (C) 1991-2023 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 -munroll-only-small-loops with -funroll-loops to unroll small
  38        loops at -O2 and above by default.  */
  39     { OPT_LEVELS_2_PLUS_SPEED_ONLY, OPT_funroll_loops, NULL, 1 },
  40     { OPT_LEVELS_2_PLUS_SPEED_ONLY, OPT_munroll_only_small_loops, NULL, 1 },
  41
  42     /* -frename-registers leads to non-optimal codegen and performance
  43        on rs6000, turn it off by default.  */
  44     { OPT_LEVELS_ALL, OPT_frename_registers, NULL, 0 },
  45
  46     /* Double growth factor to counter reduced min jump length.  */
  47     { OPT_LEVELS_ALL, OPT__param_max_grow_copy_bb_insns_, NULL, 16 },
  48     { OPT_LEVELS_NONE, 0, NULL, 0 }
  49   };
  50
  51 /* Implement TARGET_OPTION_INIT_STRUCT.  */
  52
  53 static void
  54 rs6000_option_init_struct (struct gcc_options *opts)
  55 {
  56   if (DEFAULT_ABI == ABI_DARWIN)
  57     /* The Darwin libraries never set errno, so we might as well
  58        avoid calling them when that's the only reason we would.  */
  59     opts->x_flag_errno_math = 0;
  60
  61   /* Enable section anchors by default.  */
  62   if (!TARGET_MACHO)
  63     opts->x_flag_section_anchors = 1;
  64
  65   /* By default, always emit DWARF-2 unwind info.  This allows debugging
  66      without maintaining a stack frame back-chain.  It also allows the
  67      debugger to find out where on-entry register values are stored at any
  68      point in a function, without having to analyze the executable code (which
  69      isn't even possible to do in the general case).  */
  70 #ifdef OBJECT_FORMAT_ELF
  71   opts->x_flag_asynchronous_unwind_tables = 1;
  72 #endif
  73 }
  74
  75 /* If not otherwise specified by a target, make 'long double' equivalent to
  76    'double'.  */
  77
  78 #ifndef RS6000_DEFAULT_LONG_DOUBLE_SIZE
  79 #define RS6000_DEFAULT_LONG_DOUBLE_SIZE 64
  80 #endif
  81
  82 /* Implement TARGET_HANDLE_OPTION.  */
  83
  84 static bool
  85 rs6000_handle_option (struct gcc_options *opts, struct gcc_options *opts_set,
  86                       const struct cl_decoded_option *decoded,
  87                       location_t loc)
  88 {
  89   char *p, *q;
  90   size_t code = decoded->opt_index;
  91   const char *arg = decoded->arg;
  92   int value = decoded->value;
  93
  94   switch (code)
  95     {
  96     case OPT_mfull_toc:
  97       opts->x_rs6000_isa_flags &= ~OPTION_MASK_MINIMAL_TOC;
  98       opts->x_TARGET_NO_FP_IN_TOC = 0;
  99       opts->x_TARGET_NO_SUM_IN_TOC = 0;
 100       opts_set->x_rs6000_isa_flags |= OPTION_MASK_MINIMAL_TOC;
 101 #ifdef TARGET_USES_SYSV4_OPT
 102       /* Note, V.4 no longer uses a normal TOC, so make -mfull-toc, be
 103          just the same as -mminimal-toc.  */
 104       opts->x_rs6000_isa_flags |= OPTION_MASK_MINIMAL_TOC;
 105       opts_set->x_rs6000_isa_flags |= OPTION_MASK_MINIMAL_TOC;
 106 #endif
 107       break;
 108
 109 #ifdef TARGET_USES_SYSV4_OPT
 110     case OPT_mtoc:
 111       /* Make -mtoc behave like -mminimal-toc.  */
 112       opts->x_rs6000_isa_flags |= OPTION_MASK_MINIMAL_TOC;
 113       opts_set->x_rs6000_isa_flags |= OPTION_MASK_MINIMAL_TOC;
 114       break;
 115 #endif
 116
 117 #ifdef TARGET_USES_AIX64_OPT
 118     case OPT_maix64:
 119 #else
 120     case OPT_m64:
 121 #endif
 122       opts->x_rs6000_isa_flags |= (~opts_set->x_rs6000_isa_flags
 123                                    & OPTION_MASK_PPC_GFXOPT);
 124       break;
 125
 126     case OPT_mminimal_toc:
 127       if (value == 1)
 128         {
 129           opts->x_TARGET_NO_FP_IN_TOC = 0;
 130           opts->x_TARGET_NO_SUM_IN_TOC = 0;
 131         }
 132       break;
 133
 134     case OPT_mpowerpc_gpopt:
 135     case OPT_mpowerpc_gfxopt:
 136       break;
 137
 138     case OPT_mdebug_:
 139       p = ASTRDUP (arg);
 140       opts->x_rs6000_debug = 0;
 141
 142       while ((q = strtok (p, ",")) != NULL)
 143         {
 144           unsigned mask = 0;
 145           bool invert;
 146
 147           p = NULL;
 148           if (*q == '!')
 149             {
 150               invert = true;
 151               q++;
 152             }
 153           else
 154             invert = false;
 155
 156           if (! strcmp (q, "all"))
 157             mask = MASK_DEBUG_ALL;
 158           else if (! strcmp (q, "stack"))
 159             mask = MASK_DEBUG_STACK;
 160           else if (! strcmp (q, "arg"))
 161             mask = MASK_DEBUG_ARG;
 162           else if (! strcmp (q, "reg"))
 163             mask = MASK_DEBUG_REG;
 164           else if (! strcmp (q, "addr"))
 165             mask = MASK_DEBUG_ADDR;
 166           else if (! strcmp (q, "cost"))
 167             mask = MASK_DEBUG_COST;
 168           else if (! strcmp (q, "target"))
 169             mask = MASK_DEBUG_TARGET;
 170           else if (! strcmp (q, "builtin"))
 171             mask = MASK_DEBUG_BUILTIN;
 172           else
 173             error_at (loc, "unknown %<-mdebug-%s%> switch", q);
 174
 175           if (invert)
 176             opts->x_rs6000_debug &= ~mask;
 177           else
 178             opts->x_rs6000_debug |= mask;
 179         }
 180       break;
 181
 182 #ifdef TARGET_USES_SYSV4_OPT
 183     case OPT_mrelocatable:
 184       if (value == 1)
 185         {
 186           opts->x_rs6000_isa_flags |= OPTION_MASK_MINIMAL_TOC;
 187           opts_set->x_rs6000_isa_flags |= OPTION_MASK_MINIMAL_TOC;
 188           opts->x_TARGET_NO_FP_IN_TOC = 1;
 189         }
 190       break;
 191
 192     case OPT_mrelocatable_lib:
 193       if (value == 1)
 194         {
 195           opts->x_rs6000_isa_flags |= (OPTION_MASK_RELOCATABLE
 196                                        | OPTION_MASK_MINIMAL_TOC);
 197           opts_set->x_rs6000_isa_flags |= (OPTION_MASK_RELOCATABLE
 198                                            | OPTION_MASK_MINIMAL_TOC);
 199           opts->x_TARGET_NO_FP_IN_TOC = 1;
 200         }
 201       else
 202         {
 203           opts->x_rs6000_isa_flags &= ~OPTION_MASK_RELOCATABLE;
 204           opts_set->x_rs6000_isa_flags |= OPTION_MASK_RELOCATABLE;
 205         }
 206       break;
 207 #endif
 208
 209     case OPT_mlong_double_:
 210       if (value != 64 && value != 128)
 211         {
 212           error_at (loc, "unknown switch %<-mlong-double-%s%>", arg);
 213           opts->x_rs6000_long_double_type_size
 214             = RS6000_DEFAULT_LONG_DOUBLE_SIZE;
 215           return false;
 216         }
 217       break;
 218
 219     case OPT_mabi_ibmlongdouble:
 220     case OPT_mabi_ieeelongdouble:
 221       if (opts->x_rs6000_long_double_type_size == 64)
 222         {
 223           error_at (loc, "option %<%s%> requires %<-mlong-double-128%>",
 224                     decoded->orig_option_with_args_text);
 225           return true;
 226         }
 227       break;
 228
 229     case OPT_mrecip:
 230       opts->x_rs6000_recip_name = (value) ? "default" : "none";
 231       break;
 232     }
 233   return true;
 234 }
 235
 236 /* -fsplit-stack uses a field in the TCB, available with glibc-2.19.
 237    We also allow 2.18 because alignment padding guarantees that the
 238    space is available there too.  */
 239
 240 static bool
 241 rs6000_supports_split_stack (bool report,
 242                              struct gcc_options *opts ATTRIBUTE_UNUSED)
 243 {
 244 #ifndef TARGET_GLIBC_MAJOR
 245 #define TARGET_GLIBC_MAJOR 0
 246 #endif
 247 #ifndef TARGET_GLIBC_MINOR
 248 #define TARGET_GLIBC_MINOR 0
 249 #endif
 250   /* Note: Can't test DEFAULT_ABI here, it isn't set until later.  */
 251   if (TARGET_GLIBC_MAJOR * 1000 + TARGET_GLIBC_MINOR >= 2018
 252       && TARGET_64BIT
 253       && TARGET_ELF)
 254     return true;
 255
 256   if (report)
 257     error ("%<-fsplit-stack%> currently only supported on PowerPC64 GNU/Linux with glibc-2.18 or later");
 258   return false;
 259 }
 260
 261 #undef TARGET_HANDLE_OPTION
 262 #define TARGET_HANDLE_OPTION rs6000_handle_option
 263
 264 #undef TARGET_OPTION_INIT_STRUCT
 265 #define TARGET_OPTION_INIT_STRUCT rs6000_option_init_struct
 266
 267 #undef TARGET_OPTION_OPTIMIZATION_TABLE
 268 #define TARGET_OPTION_OPTIMIZATION_TABLE rs6000_option_optimization_table
 269
 270 #undef TARGET_SUPPORTS_SPLIT_STACK
 271 #define TARGET_SUPPORTS_SPLIT_STACK rs6000_supports_split_stack
 272
 273 struct gcc_targetm_common targetm_common = TARGETM_COMMON_INITIALIZER;