gcc/config/moxie/moxie.c

   1 /* Target Code for moxie
   2    Copyright (C) 2008, 2009, 2010  Free Software Foundation
   3    Contributed by Anthony Green.
   4
   5    This file is part of GCC.
   6
   7    GCC is free software; you can redistribute it and/or modify it
   8    under the terms of the GNU General Public License as published
   9    by the Free Software Foundation; either version 3, or (at your
  10    option) any later version.
  11
  12    GCC is distributed in the hope that it will be useful, but WITHOUT
  13    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  14    or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
  15    License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with GCC; see the file COPYING3.  If not see
  19    <http://www.gnu.org/licenses/>.  */
  20
  21 #include "config.h"
  22 #include "system.h"
  23 #include "coretypes.h"
  24 #include "tm.h"
  25 #include "rtl.h"
  26 #include "regs.h"
  27 #include "hard-reg-set.h"
  28 #include "insn-config.h"
  29 #include "conditions.h"
  30 #include "insn-flags.h"
  31 #include "output.h"
  32 #include "insn-attr.h"
  33 #include "flags.h"
  34 #include "recog.h"
  35 #include "reload.h"
  36 #include "toplev.h"
  37 #include "obstack.h"
  38 #include "tree.h"
  39 #include "expr.h"
  40 #include "optabs.h"
  41 #include "except.h"
  42 #include "function.h"
  43 #include "ggc.h"
  44 #include "target.h"
  45 #include "target-def.h"
  46 #include "tm_p.h"
  47 #include "langhooks.h"
  48 #include "df.h"
  49
  50 #define LOSE_AND_RETURN(msgid, x)               \
  51   do                                            \
  52     {                                           \
  53       moxie_operand_lossage (msgid, x);         \
  54       return;                                   \
  55     } while (0)
  56
  57 /* Worker function for TARGET_RETURN_IN_MEMORY.  */
  58
  59 static bool
  60 moxie_return_in_memory (const_tree type, const_tree fntype ATTRIBUTE_UNUSED)
  61 {
  62   const HOST_WIDE_INT size = int_size_in_bytes (type);
  63   return (size == -1 || size > 2 * UNITS_PER_WORD);
  64 }
  65
  66 /* Define how to find the value returned by a function.
  67    VALTYPE is the data type of the value (as a tree).
  68    If the precise function being called is known, FUNC is its
  69    FUNCTION_DECL; otherwise, FUNC is 0.
  70
  71    We always return values in register $r0 for moxie.  */
  72
  73 static rtx
  74 moxie_function_value (const_tree valtype,
  75                       const_tree fntype_or_decl ATTRIBUTE_UNUSED,
  76                       bool outgoing ATTRIBUTE_UNUSED)
  77 {
  78   return gen_rtx_REG (TYPE_MODE (valtype), MOXIE_R0);
  79 }
  80
  81 /* Define how to find the value returned by a library function.
  82
  83    We always return values in register $r0 for moxie.  */
  84
  85 static rtx
  86 moxie_libcall_value (enum machine_mode mode,
  87                      const_rtx fun ATTRIBUTE_UNUSED)
  88 {
  89   return gen_rtx_REG (mode, MOXIE_R0);
  90 }
  91
  92 /* Handle TARGET_FUNCTION_VALUE_REGNO_P.
  93
  94    We always return values in register $r0 for moxie.  */
  95
  96 static bool
  97 moxie_function_value_regno_p (const unsigned int regno)
  98 {
  99   return (regno == MOXIE_R0);
 100 }
 101
 102 /* Emit an error message when we're in an asm, and a fatal error for
 103    "normal" insns.  Formatted output isn't easily implemented, since we
 104    use output_operand_lossage to output the actual message and handle the
 105    categorization of the error.  */
 106
 107 static void
 108 moxie_operand_lossage (const char *msgid, rtx op)
 109 {
 110   debug_rtx (op);
 111   output_operand_lossage ("%s", msgid);
 112 }
 113
 114 /* The PRINT_OPERAND_ADDRESS worker.  */
 115
 116 void
 117 moxie_print_operand_address (FILE *file, rtx x)
 118 {
 119   switch (GET_CODE (x))
 120     {
 121     case REG:
 122       fprintf (file, "(%s)", reg_names[REGNO (x)]);
 123       break;
 124
 125     case PLUS:
 126       switch (GET_CODE (XEXP (x, 1)))
 127         {
 128         case CONST_INT:
 129           fprintf (file, "%ld(%s)",
 130                    INTVAL(XEXP (x, 1)), reg_names[REGNO (XEXP (x, 0))]);
 131           break;
 132         case SYMBOL_REF:
 133           output_addr_const (file, XEXP (x, 1));
 134           fprintf (file, "(%s)", reg_names[REGNO (XEXP (x, 0))]);
 135           break;
 136         case CONST:
 137           {
 138             rtx plus = XEXP (XEXP (x, 1), 0);
 139             if (GET_CODE (XEXP (plus, 0)) == SYMBOL_REF
 140                 && CONST_INT_P (XEXP (plus, 1)))
 141               {
 142                 output_addr_const(file, XEXP (plus, 0));
 143                 fprintf (file,"+%ld(%s)", INTVAL (XEXP (plus, 1)),
 144                          reg_names[REGNO (XEXP (x, 0))]);
 145               }
 146             else
 147               abort();
 148           }
 149           break;
 150         default:
 151           abort();
 152         }
 153       break;
 154
 155     default:
 156       output_addr_const (file, x);
 157       break;
 158     }
 159 }
 160
 161 /* The PRINT_OPERAND worker.  */
 162
 163 void
 164 moxie_print_operand (FILE *file, rtx x, int code)
 165 {
 166   rtx operand = x;
 167
 168   /* New code entries should just be added to the switch below.  If
 169      handling is finished, just return.  If handling was just a
 170      modification of the operand, the modified operand should be put in
 171      "operand", and then do a break to let default handling
 172      (zero-modifier) output the operand.  */
 173
 174   switch (code)
 175     {
 176     case 0:
 177       /* No code, print as usual.  */
 178       break;
 179
 180     default:
 181       LOSE_AND_RETURN ("invalid operand modifier letter", x);
 182     }
 183
 184   /* Print an operand as without a modifier letter.  */
 185   switch (GET_CODE (operand))
 186     {
 187     case REG:
 188       if (REGNO (operand) > MOXIE_R13)
 189         internal_error ("internal error: bad register: %d", REGNO (operand));
 190       fprintf (file, "%s", reg_names[REGNO (operand)]);
 191       return;
 192
 193     case MEM:
 194       output_address (XEXP (operand, 0));
 195       return;
 196
 197     default:
 198       /* No need to handle all strange variants, let output_addr_const
 199          do it for us.  */
 200       if (CONSTANT_P (operand))
 201         {
 202           output_addr_const (file, operand);
 203           return;
 204         }
 205
 206       LOSE_AND_RETURN ("unexpected operand", x);
 207     }
 208 }
 209
 210 /* Per-function machine data.  */
 211 struct GTY(()) machine_function
 212  {
 213    /* Number of bytes saved on the stack for callee saved registers.  */
 214    int callee_saved_reg_size;
 215
 216    /* Number of bytes saved on the stack for local variables.  */
 217    int local_vars_size;
 218
 219    /* The sum of 2 sizes: locals vars and padding byte for saving the
 220     * registers.  Used in expand_prologue () and expand_epilogue().  */
 221    int size_for_adjusting_sp;
 222  };
 223
 224 /* Zero initialization is OK for all current fields.  */
 225
 226 static struct machine_function *
 227 moxie_init_machine_status (void)
 228 {
 229   return ggc_alloc_cleared_machine_function ();
 230 }
 231
 232
 233 /* The OVERRIDE_OPTIONS worker.
 234    All this curently does is set init_machine_status.  */
 235 void
 236 moxie_override_options (void)
 237 {
 238   /* Set the per-function-data initializer.  */
 239   init_machine_status = moxie_init_machine_status;
 240 }
 241
 242 /* Compute the size of the local area and the size to be adjusted by the
 243  * prologue and epilogue.  */
 244
 245 static void
 246 moxie_compute_frame (void)
 247 {
 248   /* For aligning the local variables.  */
 249   int stack_alignment = STACK_BOUNDARY / BITS_PER_UNIT;
 250   int padding_locals;
 251   int regno;
 252
 253   /* Padding needed for each element of the frame.  */
 254   cfun->machine->local_vars_size = get_frame_size ();
 255
 256   /* Align to the stack alignment.  */
 257   padding_locals = cfun->machine->local_vars_size % stack_alignment;
 258   if (padding_locals)
 259     padding_locals = stack_alignment - padding_locals;
 260
 261   cfun->machine->local_vars_size += padding_locals;
 262
 263   cfun->machine->callee_saved_reg_size = 0;
 264
 265   /* Save callee-saved registers.  */
 266   for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
 267     if (df_regs_ever_live_p (regno) && (! call_used_regs[regno]))
 268       cfun->machine->callee_saved_reg_size += 4;
 269
 270   cfun->machine->size_for_adjusting_sp =
 271     crtl->args.pretend_args_size
 272     + cfun->machine->local_vars_size
 273     + (ACCUMULATE_OUTGOING_ARGS ? crtl->outgoing_args_size : 0);
 274 }
 275
 276 void
 277 moxie_expand_prologue (void)
 278 {
 279   int regno;
 280   rtx insn;
 281
 282   moxie_compute_frame ();
 283
 284   /* Save callee-saved registers.  */
 285   for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
 286     {
 287       if (!fixed_regs[regno] && df_regs_ever_live_p (regno) && !call_used_regs[regno])
 288         {
 289           insn = emit_insn (gen_movsi_push (gen_rtx_REG (Pmode, regno)));
 290           RTX_FRAME_RELATED_P (insn) = 1;
 291         }
 292     }
 293
 294   if (cfun->machine->size_for_adjusting_sp > 0)
 295     {
 296       int i = cfun->machine->size_for_adjusting_sp;
 297       while (i > 255)
 298         {
 299           insn = emit_insn (gen_subsi3 (stack_pointer_rtx,
 300                                         stack_pointer_rtx,
 301                                         GEN_INT (255)));
 302           RTX_FRAME_RELATED_P (insn) = 1;
 303           i -= 255;
 304         }
 305       if (i > 0)
 306         {
 307           insn = emit_insn (gen_subsi3 (stack_pointer_rtx,
 308                                         stack_pointer_rtx,
 309                                         GEN_INT (i)));
 310           RTX_FRAME_RELATED_P (insn) = 1;
 311         }
 312     }
 313 }
 314
 315 void
 316 moxie_expand_epilogue (void)
 317 {
 318   int regno;
 319   rtx insn, reg, cfa_restores = NULL;
 320
 321   if (cfun->machine->callee_saved_reg_size != 0)
 322     {
 323       reg = gen_rtx_REG (Pmode, MOXIE_R5);
 324       if (cfun->machine->callee_saved_reg_size <= 255)
 325         {
 326           emit_move_insn (reg, hard_frame_pointer_rtx);
 327           emit_insn (gen_subsi3
 328                      (reg, reg,
 329                       GEN_INT (cfun->machine->callee_saved_reg_size)));
 330         }
 331       else
 332         {
 333           emit_move_insn (reg,
 334                           GEN_INT (-cfun->machine->callee_saved_reg_size));
 335           emit_insn (gen_addsi3 (reg, reg, hard_frame_pointer_rtx));
 336         }
 337       for (regno = FIRST_PSEUDO_REGISTER; regno-- > 0; )
 338         if (!fixed_regs[regno] && !call_used_regs[regno]
 339             && df_regs_ever_live_p (regno))
 340           {
 341             rtx preg = gen_rtx_REG (Pmode, regno);
 342             insn = emit_insn (gen_movsi_pop (reg, preg));
 343           }
 344     }
 345
 346   emit_jump_insn (gen_returner ());
 347 }
 348
 349 /* Implements the macro INITIAL_ELIMINATION_OFFSET, return the OFFSET.  */
 350
 351 int
 352 moxie_initial_elimination_offset (int from, int to)
 353 {
 354   int ret;
 355
 356   if ((from) == FRAME_POINTER_REGNUM && (to) == HARD_FRAME_POINTER_REGNUM)
 357     {
 358       /* Compute this since we need to use cfun->machine->local_vars_size.  */
 359       moxie_compute_frame ();
 360       ret = -cfun->machine->callee_saved_reg_size;
 361     }
 362   else if ((from) == ARG_POINTER_REGNUM && (to) == HARD_FRAME_POINTER_REGNUM)
 363     ret = 0x00;
 364   else
 365     abort ();
 366
 367   return ret;
 368 }
 369
 370 /* Worker function for TARGET_SETUP_INCOMING_VARARGS.  */
 371
 372 static void
 373 moxie_setup_incoming_varargs (CUMULATIVE_ARGS *cum,
 374                               enum machine_mode mode ATTRIBUTE_UNUSED,
 375                               tree type ATTRIBUTE_UNUSED,
 376                               int *pretend_size, int no_rtl)
 377 {
 378   int regno;
 379   int regs = 8 - *cum;
 380
 381   *pretend_size = regs < 0 ? 0 : GET_MODE_SIZE (SImode) * regs;
 382
 383   if (no_rtl)
 384     return;
 385
 386   for (regno = *cum; regno < 8; regno++)
 387     {
 388       rtx reg = gen_rtx_REG (SImode, regno);
 389       rtx slot = gen_rtx_PLUS (Pmode,
 390                                gen_rtx_REG (SImode, ARG_POINTER_REGNUM),
 391                                GEN_INT (UNITS_PER_WORD * (3 + (regno-2))));
 392
 393       emit_move_insn (gen_rtx_MEM (SImode, slot), reg);
 394     }
 395 }
 396
 397
 398 /* Return the fixed registers used for condition codes.  */
 399
 400 static bool
 401 moxie_fixed_condition_code_regs (unsigned int *p1, unsigned int *p2)
 402 {
 403   *p1 = CC_REG;
 404   *p2 = INVALID_REGNUM;
 405   return true;
 406 }
 407
 408 /* Return the next register to be used to hold a function argument or
 409    NULL_RTX if there's no more space.  */
 410
 411 rtx
 412 moxie_function_arg (CUMULATIVE_ARGS cum, enum machine_mode mode,
 413                     tree type ATTRIBUTE_UNUSED, int named ATTRIBUTE_UNUSED)
 414 {
 415   if (cum < 8)
 416     return gen_rtx_REG (mode, cum);
 417   else
 418     return NULL_RTX;
 419 }
 420
 421 /* Return non-zero if the function argument described by TYPE is to be
 422    passed by reference.  */
 423
 424 static bool
 425 moxie_pass_by_reference (CUMULATIVE_ARGS *cum ATTRIBUTE_UNUSED,
 426                          enum machine_mode mode, const_tree type,
 427                          bool named ATTRIBUTE_UNUSED)
 428 {
 429   unsigned HOST_WIDE_INT size;
 430
 431   if (type)
 432     {
 433       if (AGGREGATE_TYPE_P (type))
 434         return true;
 435       size = int_size_in_bytes (type);
 436     }
 437   else
 438     size = GET_MODE_SIZE (mode);
 439
 440   return size > 4*6;
 441 }
 442
 443 /* Some function arguments will only partially fit in the registers
 444    that hold arguments.  Given a new arg, return the number of bytes
 445    that fit in argument passing registers.  */
 446
 447 static int
 448 moxie_arg_partial_bytes (CUMULATIVE_ARGS *cum,
 449                          enum machine_mode mode,
 450                          tree type, bool named)
 451 {
 452   int bytes_left, size;
 453
 454   if (*cum >= 8)
 455     return 0;
 456
 457   if (moxie_pass_by_reference (cum, mode, type, named))
 458     size = 4;
 459   else if (type)
 460     {
 461       if (AGGREGATE_TYPE_P (type))
 462         return 0;
 463       size = int_size_in_bytes (type);
 464     }
 465   else
 466     size = GET_MODE_SIZE (mode);
 467
 468   bytes_left = (4 * 6) - ((*cum - 2) * 4);
 469
 470   if (size > bytes_left)
 471     return bytes_left;
 472   else
 473     return 0;
 474 }
 475
 476 /* Worker function for TARGET_STATIC_CHAIN.  */
 477
 478 static rtx
 479 moxie_static_chain (const_tree fndecl, bool incoming_p)
 480 {
 481   rtx addr, mem;
 482
 483   if (!DECL_STATIC_CHAIN (fndecl))
 484     return NULL;
 485
 486   if (incoming_p)
 487     addr = plus_constant (arg_pointer_rtx, 2 * UNITS_PER_WORD);
 488   else
 489     addr = plus_constant (stack_pointer_rtx, -UNITS_PER_WORD);
 490
 491   mem = gen_rtx_MEM (Pmode, addr);
 492   MEM_NOTRAP_P (mem) = 1;
 493
 494   return mem;
 495 }
 496
 497 /* Worker function for TARGET_ASM_TRAMPOLINE_TEMPLATE.  */
 498
 499 static void
 500 moxie_asm_trampoline_template (FILE *f)
 501 {
 502   fprintf (f, "\tpush  $sp, $r0\n");
 503   fprintf (f, "\tldi.l $r0, 0x0\n");
 504   fprintf (f, "\tsto.l 0x8($fp), $r0\n");
 505   fprintf (f, "\tpop   $sp, $r0\n");
 506   fprintf (f, "\tnop\n");
 507   fprintf (f, "\tjmpa  0x0\n");
 508 }
 509
 510 /* Worker function for TARGET_TRAMPOLINE_INIT.  */
 511
 512 static void
 513 moxie_trampoline_init (rtx m_tramp, tree fndecl, rtx chain_value)
 514 {
 515   rtx mem, fnaddr = XEXP (DECL_RTL (fndecl), 0);
 516
 517   emit_block_move (m_tramp, assemble_trampoline_template (),
 518                    GEN_INT (TRAMPOLINE_SIZE), BLOCK_OP_NORMAL);
 519
 520   mem = adjust_address (m_tramp, SImode, 4);
 521   emit_move_insn (mem, chain_value);
 522   mem = adjust_address (m_tramp, SImode, 20);
 523   emit_move_insn (mem, fnaddr);
 524 }
 525
 526 /* The Global `targetm' Variable.  */
 527
 528 /* Initialize the GCC target structure.  */
 529
 530 #undef  TARGET_PROMOTE_PROTOTYPES
 531 #define TARGET_PROMOTE_PROTOTYPES       hook_bool_const_tree_true
 532
 533 #undef  TARGET_RETURN_IN_MEMORY
 534 #define TARGET_RETURN_IN_MEMORY         moxie_return_in_memory
 535 #undef  TARGET_MUST_PASS_IN_STACK
 536 #define TARGET_MUST_PASS_IN_STACK       must_pass_in_stack_var_size
 537 #undef  TARGET_PASS_BY_REFERENCE
 538 #define TARGET_PASS_BY_REFERENCE        moxie_pass_by_reference
 539 #undef  TARGET_ARG_PARTIAL_BYTES
 540 #define TARGET_ARG_PARTIAL_BYTES        moxie_arg_partial_bytes
 541
 542
 543 #undef  TARGET_SETUP_INCOMING_VARARGS
 544 #define TARGET_SETUP_INCOMING_VARARGS   moxie_setup_incoming_varargs
 545
 546 #undef  TARGET_FIXED_CONDITION_CODE_REGS
 547 #define TARGET_FIXED_CONDITION_CODE_REGS moxie_fixed_condition_code_regs
 548
 549 /* Define this to return an RTX representing the place where a
 550    function returns or receives a value of data type RET_TYPE, a tree
 551    node node representing a data type.  */
 552 #undef TARGET_FUNCTION_VALUE
 553 #define TARGET_FUNCTION_VALUE moxie_function_value
 554 #undef TARGET_LIBCALL_VALUE
 555 #define TARGET_LIBCALL_VALUE moxie_libcall_value
 556 #undef TARGET_FUNCTION_VALUE_REGNO_P
 557 #define TARGET_FUNCTION_VALUE_REGNO_P moxie_function_value_regno_p
 558
 559 #undef TARGET_FRAME_POINTER_REQUIRED
 560 #define TARGET_FRAME_POINTER_REQUIRED hook_bool_void_true
 561
 562 #undef TARGET_STATIC_CHAIN
 563 #define TARGET_STATIC_CHAIN moxie_static_chain
 564 #undef TARGET_ASM_TRAMPOLINE_TEMPLATE
 565 #define TARGET_ASM_TRAMPOLINE_TEMPLATE moxie_asm_trampoline_template
 566 #undef TARGET_TRAMPOLINE_INIT
 567 #define TARGET_TRAMPOLINE_INIT moxie_trampoline_init
 568
 569 struct gcc_target targetm = TARGET_INITIALIZER;
 570
 571 #include "gt-moxie.h"