gcc/config/nios2/nios2.h

   1 /* Definitions of target machine for Altera Nios II.
   2    Copyright (C) 2012-2013 Free Software Foundation, Inc.
   3    Contributed by Jonah Graham (jgraham@altera.com),
   4    Will Reece (wreece@altera.com), and Jeff DaSilva (jdasilva@altera.com).
   5    Contributed by Mentor Graphics, Inc.
   6
   7    This file is part of GCC.
   8
   9    GCC is free software; you can redistribute it and/or modify it
  10    under the terms of the GNU General Public License as published
  11    by the Free Software Foundation; either version 3, or (at your
  12    option) any later version.
  13
  14    GCC is distributed in the hope that it will be useful, but WITHOUT
  15    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  16    or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
  17    License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with GCC; see the file COPYING3.  If not see
  21    <http://www.gnu.org/licenses/>.  */
  22
  23 #ifndef GCC_NIOS2_H
  24 #define GCC_NIOS2_H
  25
  26 /* FPU insn codes declared here.  */
  27 #include "config/nios2/nios2-opts.h"
  28
  29 /* Define built-in preprocessor macros.  */
  30 #define TARGET_CPU_CPP_BUILTINS()                   \
  31   do                                                \
  32     {                                               \
  33       builtin_define_std ("NIOS2");                 \
  34       builtin_define_std ("nios2");                 \
  35       if (TARGET_BIG_ENDIAN)                        \
  36         builtin_define_std ("nios2_big_endian");    \
  37       else                                          \
  38         builtin_define_std ("nios2_little_endian"); \
  39     }                                               \
  40   while (0)
  41
  42 /* We're little endian, unless otherwise specified by defining
  43    BIG_ENDIAN_FLAG.  */
  44 #ifndef TARGET_ENDIAN_DEFAULT
  45 # define TARGET_ENDIAN_DEFAULT 0
  46 #endif
  47
  48 /* Default target_flags if no switches specified.  */
  49 #ifndef TARGET_DEFAULT
  50 # define TARGET_DEFAULT (MASK_HAS_MUL | TARGET_ENDIAN_DEFAULT)
  51 #endif
  52
  53 #define CC1_SPEC "%{G*}"
  54
  55 #if TARGET_ENDIAN_DEFAULT == 0
  56 # define ASM_SPEC "%{!meb:-EL} %{meb:-EB}"
  57 # define LINK_SPEC_ENDIAN "%{!meb:-EL} %{meb:-EB}"
  58 # define MULTILIB_DEFAULTS { "EL" }
  59 #else
  60 # define ASM_SPEC "%{!mel:-EB} %{mel:-EL}"
  61 # define LINK_SPEC_ENDIAN "%{!mel:-EB} %{mel:-EL}"
  62 # define MULTILIB_DEFAULTS { "EB" }
  63 #endif
  64
  65 #define LINK_SPEC LINK_SPEC_ENDIAN \
  66   " %{shared:-shared} \
  67     %{static:-Bstatic}"
  68
  69
  70 /* Storage layout.  */
  71
  72 #define DEFAULT_SIGNED_CHAR 1
  73 #define BITS_BIG_ENDIAN 0
  74 #define BYTES_BIG_ENDIAN (TARGET_BIG_ENDIAN != 0)
  75 #define WORDS_BIG_ENDIAN (TARGET_BIG_ENDIAN != 0)
  76 #define BITS_PER_WORD 32
  77 #define UNITS_PER_WORD 4
  78 #define POINTER_SIZE 32
  79 #define BIGGEST_ALIGNMENT 32
  80 #define STRICT_ALIGNMENT 1
  81 #define FUNCTION_BOUNDARY 32
  82 #define PARM_BOUNDARY 32
  83 #define STACK_BOUNDARY 32
  84 #define PREFERRED_STACK_BOUNDARY 32
  85 #define MAX_FIXED_MODE_SIZE 64
  86
  87 #define CONSTANT_ALIGNMENT(EXP, ALIGN)                          \
  88   ((TREE_CODE (EXP) == STRING_CST)                              \
  89    && (ALIGN) < BITS_PER_WORD ? BITS_PER_WORD : (ALIGN))
  90
  91 /* Layout of source language data types.  */
  92
  93 #define INT_TYPE_SIZE 32
  94 #define SHORT_TYPE_SIZE 16
  95 #define LONG_TYPE_SIZE 32
  96 #define LONG_LONG_TYPE_SIZE 64
  97 #define FLOAT_TYPE_SIZE 32
  98 #define DOUBLE_TYPE_SIZE 64
  99 #define LONG_DOUBLE_TYPE_SIZE DOUBLE_TYPE_SIZE
 100
 101 #undef SIZE_TYPE
 102 #define SIZE_TYPE "unsigned int"
 103
 104 #undef PTRDIFF_TYPE
 105 #define PTRDIFF_TYPE "int"
 106
 107
 108 /* Basic characteristics of Nios II registers:
 109
 110    Regno  Name
 111    0      r0       zero    always zero
 112    1      r1       at      Assembler Temporary
 113    2-3    r2-r3            Return Location
 114    4-7    r4-r7            Register Arguments
 115    8-15   r8-r15           Caller Saved Registers
 116    16-22  r16-r22          Callee Saved Registers
 117    22     r22              Global Offset Table pointer (Linux ABI only)
 118    23     r23              Thread pointer (Linux ABI only)
 119    24     r24      et      Exception Temporary
 120    25     r25      bt      Breakpoint Temporary
 121    26     r26      gp      Global Pointer
 122    27     r27      sp      Stack Pointer
 123    28     r28      fp      Frame Pointer
 124    29     r29      ea      Exception Return Address
 125    30     r30      ba      Breakpoint Return Address
 126    31     r31      ra      Return Address
 127
 128    32     ctl0     status
 129    33     ctl1     estatus STATUS saved by exception
 130    34     ctl2     bstatus STATUS saved by break
 131    35     ctl3     ipri    Interrupt Priority Mask
 132    36     ctl4     ecause  Exception Cause
 133
 134    37     pc               Not an actual register
 135
 136    38     fake_fp          Fake Frame Pointer (always eliminated)
 137    39     fake_ap          Fake Argument Pointer (always eliminated)
 138    40                      First Pseudo Register
 139
 140    In addition, r12 is used as the static chain register and r13, r14, and r15
 141    are clobbered by PLT code sequences.
 142
 143    The definitions for all the hard register numbers are located in nios2.md.
 144 */
 145
 146 #define FIXED_REGISTERS                      \
 147   {                                          \
 148 /*        +0  1  2  3  4  5  6  7  8  9 */   \
 149 /*   0 */  1, 1, 0, 0, 0, 0, 0, 0, 0, 0,     \
 150 /*  10 */  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,     \
 151 /*  20 */  0, 0, TARGET_LINUX_ABI, TARGET_LINUX_ABI, 1, 1, 1, 1, 0, 1,     \
 152 /*  30 */  1, 0, 1, 1, 1, 1, 1, 1, 1, 1,     \
 153   }
 154
 155 /* Call used == caller saved + fixed regs + args + ret vals.  */
 156 #define CALL_USED_REGISTERS                  \
 157   {                                          \
 158 /*        +0  1  2  3  4  5  6  7  8  9 */   \
 159 /*   0 */  1, 1, 1, 1, 1, 1, 1, 1, 1, 1,     \
 160 /*  10 */  1, 1, 1, 1, 1, 1, 0, 0, 0, 0,     \
 161 /*  20 */  0, 0, TARGET_LINUX_ABI, TARGET_LINUX_ABI, 1, 1, 1, 1, 0, 1,     \
 162 /*  30 */  1, 1, 1, 1, 1, 1, 1, 1, 1, 1,     \
 163   }
 164
 165 #define MODES_TIEABLE_P(MODE1, MODE2) 1
 166 #define HARD_REGNO_MODE_OK(REGNO, MODE) 1
 167 #define HARD_REGNO_NREGS(REGNO, MODE)            \
 168   ((GET_MODE_SIZE (MODE) + UNITS_PER_WORD - 1) / UNITS_PER_WORD)
 169
 170 /* Register Classes.  */
 171
 172 enum reg_class
 173 {
 174   NO_REGS,
 175   SIB_REGS,
 176   GP_REGS,
 177   ALL_REGS,
 178   LIM_REG_CLASSES
 179 };
 180
 181 #define N_REG_CLASSES (int) LIM_REG_CLASSES
 182
 183 #define REG_CLASS_NAMES   \
 184   {  "NO_REGS",           \
 185      "SIB_REGS",          \
 186      "GP_REGS",           \
 187      "ALL_REGS" }
 188
 189 #define GENERAL_REGS ALL_REGS
 190
 191 #define REG_CLASS_CONTENTS                      \
 192   {                                             \
 193     /* NO_REGS  */ { 0, 0},                     \
 194     /* SIB_REGS */ { 0xfe0c, 0},                \
 195     /* GP_REGS  */ {~0, 0},                     \
 196     /* ALL_REGS */ {~0,~0}                      \
 197   }
 198
 199
 200 #define GP_REG_P(REGNO) ((unsigned)(REGNO) <= LAST_GP_REG)
 201 #define REGNO_REG_CLASS(REGNO) (GP_REG_P (REGNO) ? GP_REGS : ALL_REGS)
 202 #define CLASS_MAX_NREGS(CLASS, MODE)                                    \
 203   ((GET_MODE_SIZE (MODE) + UNITS_PER_WORD - 1) / UNITS_PER_WORD)
 204
 205 /* Tests for various kinds of constants used in the Nios II port.  */
 206
 207 #define SMALL_INT(X) ((unsigned HOST_WIDE_INT)(X) + 0x8000 < 0x10000)
 208 #define SMALL_INT_UNSIGNED(X) ((X) >= 0 && (X) < 0x10000)
 209 #define UPPER16_INT(X) (((X) & 0xffff) == 0)
 210 #define SHIFT_INT(X) ((X) >= 0 && (X) <= 31)
 211 #define RDWRCTL_INT(X) ((X) >= 0 && (X) <= 31)
 212 #define CUSTOM_INSN_OPCODE(X) ((X) >= 0 && (X) <= 255)
 213
 214 /* Say that the epilogue uses the return address register.  Note that
 215    in the case of sibcalls, the values "used by the epilogue" are
 216    considered live at the start of the called function.  */
 217 #define EPILOGUE_USES(REGNO) (epilogue_completed && (REGNO) == RA_REGNO)
 218
 219 /* EXIT_IGNORE_STACK should be nonzero if, when returning from a function,
 220    the stack pointer does not matter.  The value is tested only in
 221    functions that have frame pointers.
 222    No definition is equivalent to always zero.  */
 223
 224 #define EXIT_IGNORE_STACK 1
 225
 226 /* Trampolines use a 5-instruction sequence.  */
 227 #define TRAMPOLINE_SIZE 20
 228
 229 /* Stack layout.  */
 230 #define STACK_GROWS_DOWNWARD
 231 #define STARTING_FRAME_OFFSET 0
 232 #define FIRST_PARM_OFFSET(FUNDECL) 0
 233
 234 /* Before the prologue, RA lives in r31.  */
 235 #define INCOMING_RETURN_ADDR_RTX  gen_rtx_REG (VOIDmode, RA_REGNO)
 236 #define RETURN_ADDR_RTX(C,F) nios2_get_return_address (C)
 237
 238 #define DWARF_FRAME_RETURN_COLUMN RA_REGNO
 239
 240 /* The CFA includes the pretend args.  */
 241 #define ARG_POINTER_CFA_OFFSET(FNDECL) \
 242   (gcc_assert ((FNDECL) == current_function_decl), \
 243    FIRST_PARM_OFFSET (FNDECL) + crtl->args.pretend_args_size)
 244
 245 /* Frame/arg pointer elimination settings.  */
 246 #define ELIMINABLE_REGS                                                 \
 247 {{ ARG_POINTER_REGNUM,   STACK_POINTER_REGNUM},                         \
 248  { ARG_POINTER_REGNUM,   HARD_FRAME_POINTER_REGNUM},                    \
 249  { FRAME_POINTER_REGNUM, STACK_POINTER_REGNUM},                         \
 250  { FRAME_POINTER_REGNUM, HARD_FRAME_POINTER_REGNUM}}
 251
 252 #define INITIAL_ELIMINATION_OFFSET(FROM, TO, OFFSET) \
 253   (OFFSET) = nios2_initial_elimination_offset ((FROM), (TO))
 254
 255 /* Calling convention definitions.  */
 256 typedef struct nios2_args
 257 {
 258   int regs_used;
 259 } CUMULATIVE_ARGS;
 260
 261 #define NUM_ARG_REGS (LAST_ARG_REGNO - FIRST_ARG_REGNO + 1)
 262
 263 #define INIT_CUMULATIVE_ARGS(CUM, FNTYPE, LIBNAME, FNDECL, N_NAMED_ARGS) \
 264   do { (CUM).regs_used = 0; } while (0)
 265
 266 #define FUNCTION_ARG_PADDING(MODE, TYPE) \
 267   (nios2_function_arg_padding ((MODE), (TYPE)))
 268
 269 #define PAD_VARARGS_DOWN \
 270   (FUNCTION_ARG_PADDING (TYPE_MODE (type), type) == downward)
 271
 272 #define BLOCK_REG_PADDING(MODE, TYPE, FIRST) \
 273   (nios2_block_reg_padding ((MODE), (TYPE), (FIRST)))
 274
 275 #define FUNCTION_ARG_REGNO_P(REGNO) \
 276   ((REGNO) >= FIRST_ARG_REGNO && (REGNO) <= LAST_ARG_REGNO)
 277
 278 /* Passing function arguments on stack.  */
 279 #define PUSH_ARGS 0
 280 #define ACCUMULATE_OUTGOING_ARGS 1
 281
 282 /* We define TARGET_RETURN_IN_MEMORY, so set to zero.  */
 283 #define DEFAULT_PCC_STRUCT_RETURN 0
 284
 285 /* Profiling.  */
 286 #define PROFILE_BEFORE_PROLOGUE
 287 #define NO_PROFILE_COUNTERS 1
 288 #define FUNCTION_PROFILER(FILE, LABELNO) \
 289   nios2_function_profiler ((FILE), (LABELNO))
 290
 291 /* Addressing modes.  */
 292
 293 #define CONSTANT_ADDRESS_P(X) \
 294   (CONSTANT_P (X) && memory_address_p (SImode, X))
 295
 296 #define MAX_REGS_PER_ADDRESS 1
 297 #define BASE_REG_CLASS ALL_REGS
 298 #define INDEX_REG_CLASS NO_REGS
 299
 300 #define REGNO_OK_FOR_BASE_P(REGNO) nios2_regno_ok_for_base_p ((REGNO), true)
 301 #define REGNO_OK_FOR_INDEX_P(REGNO) 0
 302
 303 /* Describing Relative Costs of Operations.  */
 304 #define MOVE_MAX 4
 305 #define SLOW_BYTE_ACCESS 1
 306
 307 /* It is as good to call a constant function address as to call an address
 308    kept in a register.  */
 309 #define NO_FUNCTION_CSE
 310
 311 /* Position independent code.  */
 312
 313 #define PIC_OFFSET_TABLE_REGNUM 22
 314 #define LEGITIMATE_PIC_OPERAND_P(X) nios2_legitimate_pic_operand_p (X)
 315
 316 /* Define output assembler language.  */
 317
 318 #define ASM_APP_ON "#APP\n"
 319 #define ASM_APP_OFF "#NO_APP\n"
 320
 321 #define ASM_COMMENT_START "# "
 322
 323 #define GLOBAL_ASM_OP "\t.global\t"
 324
 325 #define REGISTER_NAMES \
 326   {                    \
 327     "zero", \
 328     "at", \
 329     "r2", \
 330     "r3", \
 331     "r4", \
 332     "r5", \
 333     "r6", \
 334     "r7", \
 335     "r8", \
 336     "r9", \
 337     "r10", \
 338     "r11", \
 339     "r12", \
 340     "r13", \
 341     "r14", \
 342     "r15", \
 343     "r16", \
 344     "r17", \
 345     "r18", \
 346     "r19", \
 347     "r20", \
 348     "r21", \
 349     "r22", \
 350     "r23", \
 351     "et", \
 352     "bt", \
 353     "gp", \
 354     "sp", \
 355     "fp", \
 356     "ta", \
 357     "ba", \
 358     "ra", \
 359     "status", \
 360     "estatus", \
 361     "bstatus", \
 362     "ipri", \
 363     "ecause", \
 364     "pc", \
 365     "fake_fp", \
 366     "fake_ap", \
 367 }
 368
 369 #define ADDITIONAL_REGISTER_NAMES       \
 370 {                                       \
 371   {"r0", 0},                            \
 372   {"r1", 1},                            \
 373   {"r24", 24},                          \
 374   {"r25", 25},                          \
 375   {"r26", 26},                          \
 376   {"r27", 27},                          \
 377   {"r28", 28},                          \
 378   {"r29", 29},                          \
 379   {"r30", 30},                          \
 380   {"r31", 31}                           \
 381 }
 382
 383 #define ASM_OUTPUT_ADDR_VEC_ELT(FILE, VALUE)  \
 384   do                                                                    \
 385     {                                                                   \
 386       fputs (integer_asm_op (POINTER_SIZE / BITS_PER_UNIT, TRUE), FILE); \
 387       fprintf (FILE, ".L%u\n", (unsigned) (VALUE));                     \
 388     }                                                                   \
 389   while (0)
 390
 391 #define ASM_OUTPUT_ADDR_DIFF_ELT(STREAM, BODY, VALUE, REL)\
 392   do                                                                    \
 393     {                                                                   \
 394       fputs (integer_asm_op (POINTER_SIZE / BITS_PER_UNIT, TRUE), STREAM); \
 395       fprintf (STREAM, ".L%u-.L%u\n", (unsigned) (VALUE), (unsigned) (REL)); \
 396     }                                                                   \
 397   while (0)
 398
 399 /* Section directives.  */
 400
 401 /* Output before read-only data.  */
 402 #define TEXT_SECTION_ASM_OP "\t.section\t.text"
 403
 404 /* Output before writable data.  */
 405 #define DATA_SECTION_ASM_OP "\t.section\t.data"
 406
 407 /* Output before uninitialized data.  */
 408 #define BSS_SECTION_ASM_OP "\t.section\t.bss"
 409
 410 /* Output before 'small' uninitialized data.  */
 411 #define SBSS_SECTION_ASM_OP "\t.section\t.sbss"
 412
 413 #ifndef IN_LIBGCC2
 414 /* Default the definition of "small data" to 8 bytes.  */
 415 extern unsigned HOST_WIDE_INT nios2_section_threshold;
 416 #endif
 417
 418 #define NIOS2_DEFAULT_GVALUE 8
 419
 420 /* This says how to output assembler code to declare an
 421    uninitialized external linkage data object.  Under SVR4,
 422    the linker seems to want the alignment of data objects
 423    to depend on their types.  We do exactly that here.  */
 424 #undef COMMON_ASM_OP
 425 #define COMMON_ASM_OP   "\t.comm\t"
 426
 427 #define ASM_OUTPUT_ALIGN(FILE, LOG)                  \
 428   do {                                               \
 429     fprintf ((FILE), "%s%d\n", ALIGN_ASM_OP, (LOG)); \
 430   } while (0)
 431
 432 #undef  ASM_OUTPUT_ALIGNED_COMMON
 433 #define ASM_OUTPUT_ALIGNED_COMMON(FILE, NAME, SIZE, ALIGN)              \
 434 do                                                                      \
 435   {                                                                     \
 436     fprintf ((FILE), "%s", COMMON_ASM_OP);                              \
 437     assemble_name ((FILE), (NAME));                                     \
 438     fprintf ((FILE), ","HOST_WIDE_INT_PRINT_UNSIGNED",%u\n", (SIZE),    \
 439              (ALIGN) / BITS_PER_UNIT);                                  \
 440   }                                                                     \
 441 while (0)
 442
 443
 444 /* This says how to output assembler code to declare an
 445    uninitialized internal linkage data object.  Under SVR4,
 446    the linker seems to want the alignment of data objects
 447    to depend on their types.  We do exactly that here.  */
 448
 449 #undef  ASM_OUTPUT_ALIGNED_LOCAL
 450 #define ASM_OUTPUT_ALIGNED_LOCAL(FILE, NAME, SIZE, ALIGN)               \
 451 do {                                                                    \
 452   if ((SIZE) <= nios2_section_threshold)                                \
 453     switch_to_section (sbss_section);                                   \
 454   else                                                                  \
 455     switch_to_section (bss_section);                                    \
 456   ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "object");                     \
 457   if (!flag_inhibit_size_directive)                                     \
 458     ASM_OUTPUT_SIZE_DIRECTIVE (FILE, NAME, SIZE);                       \
 459   ASM_OUTPUT_ALIGN ((FILE), exact_log2((ALIGN) / BITS_PER_UNIT));       \
 460   ASM_OUTPUT_LABEL(FILE, NAME);                                         \
 461   ASM_OUTPUT_SKIP((FILE), (SIZE) ? (SIZE) : 1);                         \
 462 } while (0)
 463
 464 /* Put the jump tables in .text because when using position-independent code,
 465    Nios II elf has no relocation that can represent arbitrary differences
 466    between symbols in different sections.  */
 467 #define JUMP_TABLES_IN_TEXT_SECTION 1
 468
 469 /* Exception handling.  */
 470
 471 /* Describe __builtin_eh_return.  */
 472 #define EH_RETURN_STACKADJ_RTX gen_rtx_REG (Pmode, LAST_RETVAL_REGNO)
 473 #define EH_RETURN_DATA_REGNO(N) ((N) <= (LAST_ARG_REGNO - FIRST_ARG_REGNO) \
 474                                  ? (N) + FIRST_ARG_REGNO : INVALID_REGNUM)
 475
 476 /* Nios II has no appropriate relocations for a 32-bit PC-relative or
 477    section-relative pointer encoding.  This therefore always chooses an
 478    absolute representation for pointers.  An unfortunate consequence of
 479    this is that ld complains about the absolute fde encoding when linking
 480    with -shared or -fpie, but the warning is harmless and there seems to
 481    be no good way to suppress it.  */
 482 #define ASM_PREFERRED_EH_DATA_FORMAT(CODE, GLOBAL)              \
 483   (flag_pic ? DW_EH_PE_aligned : DW_EH_PE_sdata4)
 484
 485 /* Misc. parameters.  */
 486
 487 #define STORE_FLAG_VALUE 1
 488 #define Pmode SImode
 489 #define FUNCTION_MODE QImode
 490
 491 #define CASE_VECTOR_MODE Pmode
 492
 493 #define TRULY_NOOP_TRUNCATION(OUTPREC, INPREC) 1
 494
 495 #define LOAD_EXTEND_OP(MODE) (ZERO_EXTEND)
 496
 497 #define WORD_REGISTER_OPERATIONS
 498
 499 #endif /* GCC_NIOS2_H */