[thirdparty/gcc.git] / gcc / config / score / score.c

/* Output routines for Sunplus S+CORE processor
   Copyright (C) 2005, 2007, 2008, 2009, 2010, 2011
   Free Software Foundation, Inc.
   Contributed by Sunnorth.

   This file is part of GCC.

   GCC is free software; you can redistribute it and/or modify it
   under the terms of the GNU General Public License as published
   by the Free Software Foundation; either version 3, or (at your
   option) any later version.

   GCC is distributed in the hope that it will be useful, but WITHOUT
   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
   or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
   License for more details.

   You should have received a copy of the GNU General Public License
   along with GCC; see the file COPYING3.  If not see
   <http://www.gnu.org/licenses/>.  */

#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "rtl.h"
#include "regs.h"
#include "hard-reg-set.h"
#include "insn-config.h"
#include "conditions.h"
#include "insn-attr.h"
#include "recog.h"
#include "diagnostic-core.h"
#include "output.h"
#include "tree.h"
#include "function.h"
#include "expr.h"
#include "optabs.h"
#include "flags.h"
#include "reload.h"
#include "tm_p.h"
#include "ggc.h"
#include "gstab.h"
#include "hashtab.h"
#include "debug.h"
#include "target.h"
#include "target-def.h"
#include "langhooks.h"
#include "df.h"
#include "opts.h"

#define SCORE_SDATA_MAX                score_sdata_max
#define SCORE_STACK_ALIGN(LOC)         (((LOC) + 3) & ~3)
#define SCORE_PROLOGUE_TEMP_REGNUM     (GP_REG_FIRST + 8)
#define SCORE_EPILOGUE_TEMP_REGNUM     (GP_REG_FIRST + 8)
#define SCORE_DEFAULT_SDATA_MAX        8

#define BITSET_P(VALUE, BIT)           (((VALUE) & (1L << (BIT))) != 0)
#define INS_BUF_SZ                     128

enum score_address_type
{
  SCORE_ADD_REG,
  SCORE_ADD_CONST_INT,
  SCORE_ADD_SYMBOLIC
};

struct score_frame_info
{
  HOST_WIDE_INT total_size;       /* bytes that the entire frame takes up  */
  HOST_WIDE_INT var_size;         /* bytes that variables take up  */
  HOST_WIDE_INT args_size;        /* bytes that outgoing arguments take up  */
  HOST_WIDE_INT gp_reg_size;      /* bytes needed to store gp regs  */
  HOST_WIDE_INT gp_sp_offset;     /* offset from new sp to store gp registers  */
  HOST_WIDE_INT cprestore_size;   /* # bytes that the .cprestore slot takes up  */
  unsigned int  mask;             /* mask of saved gp registers  */
  int num_gp;                     /* number of gp registers saved  */
};

struct score_arg_info
{
  unsigned int num_bytes;     /* The argument's size in bytes  */
  unsigned int reg_words;     /* The number of words passed in registers  */
  unsigned int reg_offset;    /* The offset of the first register from  */
                              /* GP_ARG_FIRST or FP_ARG_FIRST etc  */
  unsigned int stack_words;   /* The number of words that must be passed  */
                              /* on the stack  */
  unsigned int stack_offset;  /* The offset from the start of the stack  */
                              /* overflow area  */
};

#ifdef RTX_CODE
struct score_address_info
{
  enum score_address_type type;
  rtx reg;
  rtx offset;
  enum rtx_code code;
  enum score_symbol_type symbol_type;
};
#endif

static int score_sdata_max;
static char score_ins[INS_BUF_SZ + 8];

struct extern_list *extern_head = 0;

#undef  TARGET_ASM_FILE_START
#define TARGET_ASM_FILE_START           score_asm_file_start

#undef  TARGET_ASM_FILE_END
#define TARGET_ASM_FILE_END             score_asm_file_end

#undef  TARGET_ASM_FUNCTION_PROLOGUE
#define TARGET_ASM_FUNCTION_PROLOGUE    score_function_prologue

#undef  TARGET_ASM_FUNCTION_EPILOGUE
#define TARGET_ASM_FUNCTION_EPILOGUE    score_function_epilogue

#undef TARGET_OPTION_OVERRIDE
#define TARGET_OPTION_OVERRIDE          score_option_override

#undef TARGET_LEGITIMIZE_ADDRESS
#define TARGET_LEGITIMIZE_ADDRESS       score_legitimize_address

#undef  TARGET_SCHED_ISSUE_RATE
#define TARGET_SCHED_ISSUE_RATE         score_issue_rate

#undef TARGET_ASM_SELECT_RTX_SECTION
#define TARGET_ASM_SELECT_RTX_SECTION   score_select_rtx_section

#undef  TARGET_IN_SMALL_DATA_P
#define TARGET_IN_SMALL_DATA_P          score_in_small_data_p

#undef  TARGET_FUNCTION_OK_FOR_SIBCALL
#define TARGET_FUNCTION_OK_FOR_SIBCALL  score_function_ok_for_sibcall

#undef TARGET_STRICT_ARGUMENT_NAMING
#define TARGET_STRICT_ARGUMENT_NAMING   hook_bool_CUMULATIVE_ARGS_true

#undef TARGET_ASM_OUTPUT_MI_THUNK
#define TARGET_ASM_OUTPUT_MI_THUNK      score_output_mi_thunk

#undef TARGET_PROMOTE_FUNCTION_MODE
#define TARGET_PROMOTE_FUNCTION_MODE    default_promote_function_mode_always_promote

#undef TARGET_PROMOTE_PROTOTYPES
#define TARGET_PROMOTE_PROTOTYPES       hook_bool_const_tree_true

#undef TARGET_MUST_PASS_IN_STACK
#define TARGET_MUST_PASS_IN_STACK       must_pass_in_stack_var_size

#undef TARGET_ARG_PARTIAL_BYTES
#define TARGET_ARG_PARTIAL_BYTES        score_arg_partial_bytes

#undef TARGET_FUNCTION_ARG
#define TARGET_FUNCTION_ARG             score_function_arg

#undef TARGET_FUNCTION_ARG_ADVANCE
#define TARGET_FUNCTION_ARG_ADVANCE     score_function_arg_advance

#undef TARGET_PASS_BY_REFERENCE
#define TARGET_PASS_BY_REFERENCE        score_pass_by_reference

#undef TARGET_RETURN_IN_MEMORY
#define TARGET_RETURN_IN_MEMORY         score_return_in_memory

#undef TARGET_RTX_COSTS
#define TARGET_RTX_COSTS                score_rtx_costs

#undef TARGET_ADDRESS_COST
#define TARGET_ADDRESS_COST             score_address_cost

#undef TARGET_LEGITIMATE_ADDRESS_P
#define TARGET_LEGITIMATE_ADDRESS_P     score_legitimate_address_p

#undef TARGET_CAN_ELIMINATE
#define TARGET_CAN_ELIMINATE            score_can_eliminate

#undef TARGET_CONDITIONAL_REGISTER_USAGE
#define TARGET_CONDITIONAL_REGISTER_USAGE score_conditional_register_usage

#undef TARGET_ASM_TRAMPOLINE_TEMPLATE
#define TARGET_ASM_TRAMPOLINE_TEMPLATE  score_asm_trampoline_template
#undef TARGET_TRAMPOLINE_INIT
#define TARGET_TRAMPOLINE_INIT          score_trampoline_init

#undef TARGET_REGISTER_MOVE_COST
#define TARGET_REGISTER_MOVE_COST       score_register_move_cost

/* Return true if SYMBOL is a SYMBOL_REF and OFFSET + SYMBOL points
   to the same object as SYMBOL.  */
static int
score_offset_within_object_p (rtx symbol, HOST_WIDE_INT offset)
{
  if (GET_CODE (symbol) != SYMBOL_REF)
    return 0;

  if (CONSTANT_POOL_ADDRESS_P (symbol)
      && offset >= 0
      && offset < (int)GET_MODE_SIZE (get_pool_mode (symbol)))
    return 1;

  if (SYMBOL_REF_DECL (symbol) != 0
      && offset >= 0
      && offset < int_size_in_bytes (TREE_TYPE (SYMBOL_REF_DECL (symbol))))
    return 1;

  return 0;
}

/* Split X into a base and a constant offset, storing them in *BASE
   and *OFFSET respectively.  */
static void
score_split_const (rtx x, rtx *base, HOST_WIDE_INT *offset)
{
  *offset = 0;

  if (GET_CODE (x) == CONST)
    x = XEXP (x, 0);

  if (GET_CODE (x) == PLUS && GET_CODE (XEXP (x, 1)) == CONST_INT)
    {
      *offset += INTVAL (XEXP (x, 1));
      x = XEXP (x, 0);
    }

  *base = x;
}

/* Classify symbol X, which must be a SYMBOL_REF or a LABEL_REF.  */
static enum score_symbol_type
score_classify_symbol (rtx x)
{
  if (GET_CODE (x) == LABEL_REF)
    return SYMBOL_GENERAL;

  gcc_assert (GET_CODE (x) == SYMBOL_REF);

  if (CONSTANT_POOL_ADDRESS_P (x))
    {
      if (GET_MODE_SIZE (get_pool_mode (x)) <= SCORE_SDATA_MAX)
        return SYMBOL_SMALL_DATA;
      return SYMBOL_GENERAL;
    }
  if (SYMBOL_REF_SMALL_P (x))
    return SYMBOL_SMALL_DATA;
  return SYMBOL_GENERAL;
}

/* Return true if the current function must save REGNO.  */
static int
score_save_reg_p (unsigned int regno)
{
  /* Check call-saved registers.  */
  if (df_regs_ever_live_p (regno) && !call_used_regs[regno])
    return 1;

  /* We need to save the old frame pointer before setting up a new one.  */
  if (regno == HARD_FRAME_POINTER_REGNUM && frame_pointer_needed)
    return 1;

  /* We need to save the incoming return address if it is ever clobbered
     within the function.  */
  if (regno == RA_REGNUM && df_regs_ever_live_p (regno))
    return 1;

  return 0;
}

/* Return one word of double-word value OP, taking into account the fixed
   endianness of certain registers.  HIGH_P is true to select the high part,
   false to select the low part.  */
static rtx
score_subw (rtx op, int high_p)
{
  unsigned int byte;
  enum machine_mode mode = GET_MODE (op);

  if (mode == VOIDmode)
    mode = DImode;

  byte = (TARGET_LITTLE_ENDIAN ? high_p : !high_p) ? UNITS_PER_WORD : 0;

  if (GET_CODE (op) == REG && REGNO (op) == HI_REGNUM)
    return gen_rtx_REG (SImode, high_p ? HI_REGNUM : LO_REGNUM);

  if (GET_CODE (op) == MEM)
    return adjust_address (op, SImode, byte);

  return simplify_gen_subreg (SImode, op, mode, byte);
}

static struct score_frame_info *
score_cached_frame (void)
{
  static struct score_frame_info _frame_info;
  return &_frame_info;
}

/* Return the bytes needed to compute the frame pointer from the current
   stack pointer.  SIZE is the size (in bytes) of the local variables.  */
static struct score_frame_info *
score_compute_frame_size (HOST_WIDE_INT size)
{
  unsigned int regno;
  struct score_frame_info *f = score_cached_frame ();

  memset (f, 0, sizeof (struct score_frame_info));
  f->gp_reg_size = 0;
  f->mask = 0;
  f->var_size = SCORE_STACK_ALIGN (size);
  f->args_size = crtl->outgoing_args_size;
  f->cprestore_size = flag_pic ? UNITS_PER_WORD : 0;
  if (f->var_size == 0 && crtl->is_leaf)
    f->args_size = f->cprestore_size = 0;

  if (f->args_size == 0 && cfun->calls_alloca)
    f->args_size = UNITS_PER_WORD;

  f->total_size = f->var_size + f->args_size + f->cprestore_size;
  for (regno = GP_REG_FIRST; regno <= GP_REG_LAST; regno++)
    {
      if (score_save_reg_p (regno))
        {
          f->gp_reg_size += GET_MODE_SIZE (SImode);
          f->mask |= 1 << (regno - GP_REG_FIRST);
        }
    }

  if (crtl->calls_eh_return)
    {
      unsigned int i;
      for (i = 0;; ++i)
        {
          regno = EH_RETURN_DATA_REGNO (i);
          if (regno == INVALID_REGNUM)
            break;
          f->gp_reg_size += GET_MODE_SIZE (SImode);
          f->mask |= 1 << (regno - GP_REG_FIRST);
        }
    }

  f->total_size += f->gp_reg_size;
  f->num_gp = f->gp_reg_size / UNITS_PER_WORD;

  if (f->mask)
    {
      HOST_WIDE_INT offset;
      offset = (f->args_size + f->cprestore_size + f->var_size
                + f->gp_reg_size - GET_MODE_SIZE (SImode));
      f->gp_sp_offset = offset;
    }
  else
    f->gp_sp_offset = 0;

  return f;
}

/* Return true if X is a valid base register for the given mode.
   Allow only hard registers if STRICT.  */
static int
score_valid_base_register_p (rtx x, int strict)
{
  if (!strict && GET_CODE (x) == SUBREG)
    x = SUBREG_REG (x);

  return (GET_CODE (x) == REG
          && score_regno_mode_ok_for_base_p (REGNO (x), strict));
}

/* Return true if X is a valid address for machine mode MODE.  If it is,
   fill in INFO appropriately.  STRICT is true if we should only accept
   hard base registers.  */
static int
score_classify_address (struct score_address_info *info,
                        enum machine_mode mode, rtx x, int strict)
{
  info->code = GET_CODE (x);

  switch (info->code)
    {
    case REG:
    case SUBREG:
      info->type = SCORE_ADD_REG;
      info->reg = x;
      info->offset = const0_rtx;
      return score_valid_base_register_p (info->reg, strict);
    case PLUS:
      info->type = SCORE_ADD_REG;
      info->reg = XEXP (x, 0);
      info->offset = XEXP (x, 1);
      return (score_valid_base_register_p (info->reg, strict)
              && GET_CODE (info->offset) == CONST_INT
              && IMM_IN_RANGE (INTVAL (info->offset), 15, 1));
    case PRE_DEC:
    case POST_DEC:
    case PRE_INC:
    case POST_INC:
      if (GET_MODE_SIZE (mode) > GET_MODE_SIZE (SImode))
        return false;
      info->type = SCORE_ADD_REG;
      info->reg = XEXP (x, 0);
      info->offset = GEN_INT (GET_MODE_SIZE (mode));
      return score_valid_base_register_p (info->reg, strict);
    case CONST_INT:
      info->type = SCORE_ADD_CONST_INT;
      return IMM_IN_RANGE (INTVAL (x), 15, 1);
    case CONST:
    case LABEL_REF:
    case SYMBOL_REF:
      info->type = SCORE_ADD_SYMBOLIC;
      return (score_symbolic_constant_p (x, &info->symbol_type)
              && (info->symbol_type == SYMBOL_GENERAL
                  || info->symbol_type == SYMBOL_SMALL_DATA));
    default:
      return 0;
    }
}

/* Implement TARGET_RETURN_IN_MEMORY.  In S+core,
   small structures are returned in a register.
   Objects with varying size must still be returned in memory.  */
static bool
score_return_in_memory (const_tree type, const_tree fndecl ATTRIBUTE_UNUSED)
{
    return ((TYPE_MODE (type) == BLKmode)
            || (int_size_in_bytes (type) > 2 * UNITS_PER_WORD)
            || (int_size_in_bytes (type) == -1));
}

/* Return a legitimate address for REG + OFFSET.  */
static rtx
score_add_offset (rtx reg, HOST_WIDE_INT offset)
{
  if (!IMM_IN_RANGE (offset, 15, 1))
    {
      reg = expand_simple_binop (GET_MODE (reg), PLUS,
                                 gen_int_mode (offset & 0xffffc000,
                                               GET_MODE (reg)),
                                 reg, NULL, 0, OPTAB_WIDEN);
      offset &= 0x3fff;
    }

  return plus_constant (GET_MODE (reg), reg, offset);
}

/* Implement TARGET_ASM_OUTPUT_MI_THUNK.  Generate rtl rather than asm text
   in order to avoid duplicating too much logic from elsewhere.  */
static void
score_output_mi_thunk (FILE *file, tree thunk_fndecl ATTRIBUTE_UNUSED,
                       HOST_WIDE_INT delta, HOST_WIDE_INT vcall_offset,
                       tree function)
{
  rtx this_rtx, temp1, insn, fnaddr;

  /* Pretend to be a post-reload pass while generating rtl.  */
  reload_completed = 1;

  /* Mark the end of the (empty) prologue.  */
  emit_note (NOTE_INSN_PROLOGUE_END);

  /* We need two temporary registers in some cases.  */
  temp1 = gen_rtx_REG (Pmode, 8);

  /* Find out which register contains the "this" pointer.  */
  if (aggregate_value_p (TREE_TYPE (TREE_TYPE (function)), function))
    this_rtx = gen_rtx_REG (Pmode, ARG_REG_FIRST + 1);
  else
    this_rtx = gen_rtx_REG (Pmode, ARG_REG_FIRST);

  /* Add DELTA to THIS_RTX.  */
  if (delta != 0)
    {
      rtx offset = GEN_INT (delta);
      if (!(delta >= -32768 && delta <= 32767))
        {
          emit_move_insn (temp1, offset);
          offset = temp1;
        }
      emit_insn (gen_add3_insn (this_rtx, this_rtx, offset));
    }

  /* If needed, add *(*THIS_RTX + VCALL_OFFSET) to THIS_RTX.  */
  if (vcall_offset != 0)
    {
      rtx addr;

      /* Set TEMP1 to *THIS_RTX.  */
      emit_move_insn (temp1, gen_rtx_MEM (Pmode, this_rtx));

      /* Set ADDR to a legitimate address for *THIS_RTX + VCALL_OFFSET.  */
      addr = score_add_offset (temp1, vcall_offset);

      /* Load the offset and add it to THIS_RTX.  */
      emit_move_insn (temp1, gen_rtx_MEM (Pmode, addr));
      emit_insn (gen_add3_insn (this_rtx, this_rtx, temp1));
    }

  /* Jump to the target function.  */
  fnaddr = XEXP (DECL_RTL (function), 0);
  insn = emit_call_insn (gen_sibcall_internal_score7 (fnaddr, const0_rtx));
  SIBLING_CALL_P (insn) = 1;

  /* Run just enough of rest_of_compilation.  This sequence was
     "borrowed" from alpha.c.  */
  insn = get_insns ();
  insn_locators_alloc ();
  split_all_insns_noflow ();
  shorten_branches (insn);
  final_start_function (insn, file, 1);
  final (insn, file, 1);
  final_end_function ();

  /* Clean up the vars set above.  Note that final_end_function resets
     the global pointer for us.  */
  reload_completed = 0;
}

/* Copy VALUE to a register and return that register.  If new psuedos
   are allowed, copy it into a new register, otherwise use DEST.  */
static rtx
score_force_temporary (rtx dest, rtx value)
{
  if (can_create_pseudo_p ())
    return force_reg (Pmode, value);
  else
    {
      emit_move_insn (copy_rtx (dest), value);
      return dest;
    }
}

/* Return a LO_SUM expression for ADDR.  TEMP is as for score_force_temporary
   and is used to load the high part into a register.  */
static rtx
score_split_symbol (rtx temp, rtx addr)
{
  rtx high = score_force_temporary (temp,
                                     gen_rtx_HIGH (Pmode, copy_rtx (addr)));
  return gen_rtx_LO_SUM (Pmode, high, addr);
}

/* This function is used to implement LEGITIMIZE_ADDRESS.  If X can
   be legitimized in a way that the generic machinery might not expect,
   return the new address.  */
static rtx
score_legitimize_address (rtx x)
{
  enum score_symbol_type symbol_type;

  if (score_symbolic_constant_p (x, &symbol_type)
      && symbol_type == SYMBOL_GENERAL)
    return score_split_symbol (0, x);

  if (GET_CODE (x) == PLUS
      && GET_CODE (XEXP (x, 1)) == CONST_INT)
    {
      rtx reg = XEXP (x, 0);
      if (!score_valid_base_register_p (reg, 0))
        reg = copy_to_mode_reg (Pmode, reg);
      return score_add_offset (reg, INTVAL (XEXP (x, 1)));
    }

  return x;
}

/* Fill INFO with information about a single argument.  CUM is the
   cumulative state for earlier arguments.  MODE is the mode of this
   argument and TYPE is its type (if known).  NAMED is true if this
   is a named (fixed) argument rather than a variable one.  */
static void
score_classify_arg (const CUMULATIVE_ARGS *cum, enum machine_mode mode,
                    const_tree type, bool named, struct score_arg_info *info)
{
  int even_reg_p;
  unsigned int num_words, max_regs;

  even_reg_p = 0;
  if (GET_MODE_CLASS (mode) == MODE_INT
      || GET_MODE_CLASS (mode) == MODE_FLOAT)
    even_reg_p = (GET_MODE_SIZE (mode) > UNITS_PER_WORD);
  else
    if (type != NULL_TREE && TYPE_ALIGN (type) > BITS_PER_WORD && named)
      even_reg_p = 1;

  if (TARGET_MUST_PASS_IN_STACK (mode, type))
    info->reg_offset = ARG_REG_NUM;
  else
    {
      info->reg_offset = cum->num_gprs;
      if (even_reg_p)
        info->reg_offset += info->reg_offset & 1;
    }

  if (mode == BLKmode)
    info->num_bytes = int_size_in_bytes (type);
  else
    info->num_bytes = GET_MODE_SIZE (mode);

  num_words = (info->num_bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
  max_regs = ARG_REG_NUM - info->reg_offset;

  /* Partition the argument between registers and stack.  */
  info->reg_words = MIN (num_words, max_regs);
  info->stack_words = num_words - info->reg_words;

  /* The alignment applied to registers is also applied to stack arguments.  */
  if (info->stack_words)
    {
      info->stack_offset = cum->stack_words;
      if (even_reg_p)
        info->stack_offset += info->stack_offset & 1;
    }
}

/* Set up the stack and frame (if desired) for the function.  */
static void
score_function_prologue (FILE *file, HOST_WIDE_INT size ATTRIBUTE_UNUSED)
{
  const char *fnname;
  struct score_frame_info *f = score_cached_frame ();
  HOST_WIDE_INT tsize = f->total_size;

  fnname = XSTR (XEXP (DECL_RTL (current_function_decl), 0), 0);
  if (!flag_inhibit_size_directive)
    {
      fputs ("\t.ent\t", file);
      assemble_name (file, fnname);
      fputs ("\n", file);
    }
  assemble_name (file, fnname);
  fputs (":\n", file);

  if (!flag_inhibit_size_directive)
    {
      fprintf (file,
               "\t.frame\t%s," HOST_WIDE_INT_PRINT_DEC ",%s, %d\t\t"
               "# vars= " HOST_WIDE_INT_PRINT_DEC ", regs= %d"
               ", args= " HOST_WIDE_INT_PRINT_DEC
               ", gp= " HOST_WIDE_INT_PRINT_DEC "\n",
               (reg_names[(frame_pointer_needed)
                ? HARD_FRAME_POINTER_REGNUM : STACK_POINTER_REGNUM]),
               tsize,
               reg_names[RA_REGNUM],
               crtl->is_leaf ? 1 : 0,
               f->var_size,
               f->num_gp,
               f->args_size,
               f->cprestore_size);

      fprintf(file, "\t.mask\t0x%08x," HOST_WIDE_INT_PRINT_DEC "\n",
              f->mask,
              (f->gp_sp_offset - f->total_size));
    }
}

/* Do any necessary cleanup after a function to restore stack, frame,
   and regs.  */
static void
score_function_epilogue (FILE *file, HOST_WIDE_INT size ATTRIBUTE_UNUSED)
{
  if (!flag_inhibit_size_directive)
    {
      const char *fnname;
      fnname = XSTR (XEXP (DECL_RTL (current_function_decl), 0), 0);
      fputs ("\t.end\t", file);
      assemble_name (file, fnname);
      fputs ("\n", file);
    }
}

/* Returns true if X contains a SYMBOL_REF.  */
static bool
score_symbolic_expression_p (rtx x)
{
  if (GET_CODE (x) == SYMBOL_REF)
    return true;

  if (GET_CODE (x) == CONST)
    return score_symbolic_expression_p (XEXP (x, 0));

  if (UNARY_P (x))
    return score_symbolic_expression_p (XEXP (x, 0));

  if (ARITHMETIC_P (x))
    return (score_symbolic_expression_p (XEXP (x, 0))
            || score_symbolic_expression_p (XEXP (x, 1)));

  return false;
}

/* Choose the section to use for the constant rtx expression X that has
   mode MODE.  */
static section *
score_select_rtx_section (enum machine_mode mode, rtx x, unsigned HOST_WIDE_INT align)
{
  if (GET_MODE_SIZE (mode) <= SCORE_SDATA_MAX)
    return get_named_section (0, ".sdata", 0);
  else if (flag_pic && score_symbolic_expression_p (x))
    return get_named_section (0, ".data.rel.ro", 3);
  else
    return mergeable_constant_section (mode, align, 0);
}

/* Implement TARGET_IN_SMALL_DATA_P.  */
static bool
score_in_small_data_p (const_tree decl)
{
  HOST_WIDE_INT size;

  if (TREE_CODE (decl) == STRING_CST
      || TREE_CODE (decl) == FUNCTION_DECL)
    return false;

  if (TREE_CODE (decl) == VAR_DECL && DECL_SECTION_NAME (decl) != 0)
    {
      const char *name;
      name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl));
      if (strcmp (name, ".sdata") != 0
          && strcmp (name, ".sbss") != 0)
        return true;
      if (!DECL_EXTERNAL (decl))
        return false;
    }
  size = int_size_in_bytes (TREE_TYPE (decl));
  return (size > 0 && size <= SCORE_SDATA_MAX);
}

/* Implement TARGET_ASM_FILE_START.  */
static void
score_asm_file_start (void)
{
  default_file_start ();
  fprintf (asm_out_file, ASM_COMMENT_START
           "GCC for S+core %s \n", SCORE_GCC_VERSION);

  if (flag_pic)
    fprintf (asm_out_file, "\t.set pic\n");
}

/* Implement TARGET_ASM_FILE_END.  When using assembler macros, emit
   .externs for any small-data variables that turned out to be external.  */
static void
score_asm_file_end (void)
{
  tree name_tree;
  struct extern_list *p;
  if (extern_head)
    {
      fputs ("\n", asm_out_file);
      for (p = extern_head; p != 0; p = p->next)
        {
          name_tree = get_identifier (p->name);
          if (!TREE_ASM_WRITTEN (name_tree)
              && TREE_SYMBOL_REFERENCED (name_tree))
            {
              TREE_ASM_WRITTEN (name_tree) = 1;
              fputs ("\t.extern\t", asm_out_file);
              assemble_name (asm_out_file, p->name);
              fprintf (asm_out_file, ", %d\n", p->size);
            }
        }
    }
}

/* Implement TARGET_OPTION_OVERRIDE hook.  */
static void
score_option_override (void)
{
  flag_pic = false;
  score_sdata_max = SCORE_DEFAULT_SDATA_MAX;

}

/* Implement REGNO_REG_CLASS macro.  */
int
score_reg_class (int regno)
{
  int c;
  gcc_assert (regno >= 0 && regno < FIRST_PSEUDO_REGISTER);

  if (regno == FRAME_POINTER_REGNUM
      || regno == ARG_POINTER_REGNUM)
    return ALL_REGS;

  for (c = 0; c < N_REG_CLASSES; c++)
    if (TEST_HARD_REG_BIT (reg_class_contents[c], regno))
      return c;

  return NO_REGS;
}

/* Implement PREFERRED_RELOAD_CLASS macro.  */
enum reg_class
score_preferred_reload_class (rtx x ATTRIBUTE_UNUSED, enum reg_class rclass)
{
  if (reg_class_subset_p (G16_REGS, rclass))
    return G16_REGS;
  if (reg_class_subset_p (G32_REGS, rclass))
    return G32_REGS;
  return rclass;
}

/* Implement SECONDARY_INPUT_RELOAD_CLASS
   and SECONDARY_OUTPUT_RELOAD_CLASS macro.  */
enum reg_class
score_secondary_reload_class (enum reg_class rclass,
                              enum machine_mode mode ATTRIBUTE_UNUSED,
                              rtx x)
{
  int regno = -1;
  if (GET_CODE (x) == REG || GET_CODE(x) == SUBREG)
    regno = true_regnum (x);

  if (!GR_REG_CLASS_P (rclass))
    return GP_REG_P (regno) ? NO_REGS : G32_REGS;
  return NO_REGS;
}


/* Return truth value on whether or not a given hard register
   can support a given mode.  */
int
score_hard_regno_mode_ok (unsigned int regno, enum machine_mode mode)
{
  int size = GET_MODE_SIZE (mode);
  enum mode_class mclass = GET_MODE_CLASS (mode);

  if (mclass == MODE_CC)
    return regno == CC_REGNUM;
  else if (regno == FRAME_POINTER_REGNUM
           || regno == ARG_POINTER_REGNUM)
    return mclass == MODE_INT;
  else if (GP_REG_P (regno))
    /* ((regno <= (GP_REG_LAST- HARD_REGNO_NREGS (dummy, mode)) + 1)  */
    return !(regno & 1) || (size <= UNITS_PER_WORD);
  else if (CE_REG_P (regno))
    return (mclass == MODE_INT
            && ((size <= UNITS_PER_WORD)
                || (regno == CE_REG_FIRST && size == 2 * UNITS_PER_WORD)));
  else
    return (mclass == MODE_INT) && (size <= UNITS_PER_WORD);
}

/* Implement INITIAL_ELIMINATION_OFFSET.  FROM is either the frame
   pointer or argument pointer.  TO is either the stack pointer or
   hard frame pointer.  */
HOST_WIDE_INT
score_initial_elimination_offset (int from,
                                  int to ATTRIBUTE_UNUSED)
{
  struct score_frame_info *f = score_compute_frame_size (get_frame_size ());
  switch (from)
    {
    case ARG_POINTER_REGNUM:
      return f->total_size;
    case FRAME_POINTER_REGNUM:
      return 0;
    default:
      gcc_unreachable ();
    }
}

/* Implement TARGET_FUNCTION_ARG_ADVANCE hook.  */
static void
score_function_arg_advance (cumulative_args_t cum_args, enum machine_mode mode,
                            const_tree type, bool named)
{
  struct score_arg_info info;
  CUMULATIVE_ARGS *cum = get_cumulative_args (cum_args);
  score_classify_arg (cum, mode, type, named, &info);
  cum->num_gprs = info.reg_offset + info.reg_words;
  if (info.stack_words > 0)
    cum->stack_words = info.stack_offset + info.stack_words;
  cum->arg_number++;
}

/* Implement TARGET_ARG_PARTIAL_BYTES macro.  */
int
score_arg_partial_bytes (cumulative_args_t cum_args,
                         enum machine_mode mode, tree type, bool named)
{
  struct score_arg_info info;
  CUMULATIVE_ARGS *cum = get_cumulative_args (cum_args);
  score_classify_arg (cum, mode, type, named, &info);
  return info.stack_words > 0 ? info.reg_words * UNITS_PER_WORD : 0;
}

/* Implement TARGET_FUNCTION_ARG hook.  */
static rtx
score_function_arg (cumulative_args_t cum_args, enum machine_mode mode,
                    const_tree type, bool named)
{
  struct score_arg_info info;
  CUMULATIVE_ARGS *cum = get_cumulative_args (cum_args);

  if (mode == VOIDmode || !named)
    return 0;

  score_classify_arg (cum, mode, type, named, &info);

  if (info.reg_offset == ARG_REG_NUM)
    return 0;

  if (!info.stack_words)
    return gen_rtx_REG (mode, ARG_REG_FIRST + info.reg_offset);
  else
    {
      rtx ret = gen_rtx_PARALLEL (mode, rtvec_alloc (info.reg_words));
      unsigned int i, part_offset = 0;
      for (i = 0; i < info.reg_words; i++)
        {
          rtx reg;
          reg = gen_rtx_REG (SImode, ARG_REG_FIRST + info.reg_offset + i);
          XVECEXP (ret, 0, i) = gen_rtx_EXPR_LIST (SImode, reg,
                                                   GEN_INT (part_offset));
          part_offset += UNITS_PER_WORD;
        }
      return ret;
    }
}

/* Implement FUNCTION_VALUE and LIBCALL_VALUE.  For normal calls,
   VALTYPE is the return type and MODE is VOIDmode.  For libcalls,
   VALTYPE is null and MODE is the mode of the return value.  */
rtx
score_function_value (const_tree valtype, const_tree func, enum machine_mode mode)
{
  if (valtype)
    {
      int unsignedp;
      mode = TYPE_MODE (valtype);
      unsignedp = TYPE_UNSIGNED (valtype);
      mode = promote_function_mode (valtype, mode, &unsignedp, func, 1);
    }
  return gen_rtx_REG (mode, RT_REGNUM);
}

/* Implement TARGET_ASM_TRAMPOLINE_TEMPLATE.  */

static void
score_asm_trampoline_template (FILE *f)
{
  fprintf (f, "\t.set r1\n");
  fprintf (f, "\tmv r31, r3\n");
  fprintf (f, "\tbl nextinsn\n");
  fprintf (f, "nextinsn:\n");
  fprintf (f, "\tlw r1, [r3, 6*4-8]\n");
  fprintf (f, "\tlw r23, [r3, 6*4-4]\n");
  fprintf (f, "\tmv r3, r31\n");
  fprintf (f, "\tbr! r1\n");
  fprintf (f, "\tnop!\n");
  fprintf (f, "\t.set nor1\n");
}

/* Implement TARGET_TRAMPOLINE_INIT.  */
static void
score_trampoline_init (rtx m_tramp, tree fndecl, rtx chain_value)
{
#define CODE_SIZE        (TRAMPOLINE_INSNS * UNITS_PER_WORD)

  rtx fnaddr = XEXP (DECL_RTL (fndecl), 0);
  rtx mem;

  emit_block_move (m_tramp, assemble_trampoline_template (),
                   GEN_INT (TRAMPOLINE_SIZE), BLOCK_OP_NORMAL);

  mem = adjust_address (m_tramp, SImode, CODE_SIZE);
  emit_move_insn (mem, fnaddr);
  mem = adjust_address (m_tramp, SImode, CODE_SIZE + GET_MODE_SIZE (SImode));
  emit_move_insn (mem, chain_value);

#undef CODE_SIZE
}

/* This function is used to implement REG_MODE_OK_FOR_BASE_P macro.  */
int
score_regno_mode_ok_for_base_p (int regno, int strict)
{
  if (regno >= FIRST_PSEUDO_REGISTER)
    {
      if (!strict)
        return 1;
      regno = reg_renumber[regno];
    }
  if (regno == ARG_POINTER_REGNUM
      || regno == FRAME_POINTER_REGNUM)
    return 1;
  return GP_REG_P (regno);
}

/* Implement TARGET_LEGITIMATE_ADDRESS_P macro.  */
static bool
score_legitimate_address_p (enum machine_mode mode, rtx x, bool strict)
{
  struct score_address_info addr;

  return score_classify_address (&addr, mode, x, strict);
}

/* Implement TARGET_REGISTER_MOVE_COST.

   Return a number assessing the cost of moving a register in class
   FROM to class TO. */
static int
score_register_move_cost (enum machine_mode mode ATTRIBUTE_UNUSED,
                          reg_class_t from, reg_class_t to)
{
  if (GR_REG_CLASS_P (from))
    {
      if (GR_REG_CLASS_P (to))
        return 2;
      else if (SP_REG_CLASS_P (to))
        return 4;
      else if (CP_REG_CLASS_P (to))
        return 5;
      else if (CE_REG_CLASS_P (to))
        return 6;
    }
  if (GR_REG_CLASS_P (to))
    {
      if (GR_REG_CLASS_P (from))
        return 2;
      else if (SP_REG_CLASS_P (from))
        return 4;
      else if (CP_REG_CLASS_P (from))
        return 5;
      else if (CE_REG_CLASS_P (from))
        return 6;
    }
  return 12;
}

/* Return the number of instructions needed to load a symbol of the
   given type into a register.  */
static int
score_symbol_insns (enum score_symbol_type type)
{
  switch (type)
    {
    case SYMBOL_GENERAL:
      return 2;

    case SYMBOL_SMALL_DATA:
      return 1;
    }

  gcc_unreachable ();
}

/* Return the number of instructions needed to load or store a value
   of mode MODE at X.  Return 0 if X isn't valid for MODE.  */
static int
score_address_insns (rtx x, enum machine_mode mode)
{
  struct score_address_info addr;
  int factor;

  if (mode == BLKmode)
    factor = 1;
  else
    factor = (GET_MODE_SIZE (mode) + UNITS_PER_WORD - 1) / UNITS_PER_WORD;

  if (score_classify_address (&addr, mode, x, false))
    switch (addr.type)
      {
      case SCORE_ADD_REG:
      case SCORE_ADD_CONST_INT:
        return factor;

      case SCORE_ADD_SYMBOLIC:
        return factor * score_symbol_insns (addr.symbol_type);
      }
  return 0;
}

/* Implement TARGET_RTX_COSTS macro.  */
bool
score_rtx_costs (rtx x, int code, int outer_code, int opno ATTRIBUTE_UNUSED,
                 int *total, bool speed ATTRIBUTE_UNUSED)
{
  enum machine_mode mode = GET_MODE (x);

  switch (code)
    {
    case CONST_INT:
      if (outer_code == SET)
        {
          if (((INTVAL (x) & 0xffff) == 0) 
              || (INTVAL (x) >= -32768 && INTVAL (x) <= 32767))
            *total = COSTS_N_INSNS (1);
          else
            *total = COSTS_N_INSNS (2);
        }
      else if (outer_code == PLUS || outer_code == MINUS)
        {
          if (INTVAL (x) >= -8192 && INTVAL (x) <= 8191)
            *total = 0;
          else if (((INTVAL (x) & 0xffff) == 0)
                   || (INTVAL (x) >= -32768 && INTVAL (x) <= 32767))
            *total = 1;
          else
            *total = COSTS_N_INSNS (2);
        }
      else if (outer_code == AND || outer_code == IOR)
        {
          if (INTVAL (x) >= 0 && INTVAL (x) <= 16383)
            *total = 0;
          else if (((INTVAL (x) & 0xffff) == 0)
                   || (INTVAL (x) >= 0 && INTVAL (x) <= 65535))
            *total = 1;
          else
            *total = COSTS_N_INSNS (2);
        }
      else
        {
          *total = 0;
        }
      return true;

    case CONST:
    case SYMBOL_REF:
    case LABEL_REF:
    case CONST_DOUBLE:
      *total = COSTS_N_INSNS (2);
      return true;

    case MEM:
      {
        /* If the address is legitimate, return the number of
           instructions it needs, otherwise use the default handling.  */
        int n = score_address_insns (XEXP (x, 0), GET_MODE (x));
        if (n > 0)
          {
            *total = COSTS_N_INSNS (n + 1);
            return true;
          }
        return false;
      }

    case FFS:
      *total = COSTS_N_INSNS (6);
      return true;

    case NOT:
      *total = COSTS_N_INSNS (1);
      return true;

    case AND:
    case IOR:
    case XOR:
      if (mode == DImode)
        {
          *total = COSTS_N_INSNS (2);
          return true;
        }
      return false;

    case ASHIFT:
    case ASHIFTRT:
    case LSHIFTRT:
      if (mode == DImode)
        {
          *total = COSTS_N_INSNS ((GET_CODE (XEXP (x, 1)) == CONST_INT)
                                  ? 4 : 12);
          return true;
        }
      return false;

    case ABS:
      *total = COSTS_N_INSNS (4);
      return true;

    case PLUS:
    case MINUS:
      if (mode == DImode)
        {
          *total = COSTS_N_INSNS (4);
          return true;
        }
      *total = COSTS_N_INSNS (1);
      return true;

    case NEG:
      if (mode == DImode)
        {
          *total = COSTS_N_INSNS (4);
          return true;
        }
      return false;

    case MULT:
      *total = optimize_size ? COSTS_N_INSNS (2) : COSTS_N_INSNS (12);
      return true;

    case DIV:
    case MOD:
    case UDIV:
    case UMOD:
      *total = optimize_size ? COSTS_N_INSNS (2) : COSTS_N_INSNS (33);
      return true;

    case SIGN_EXTEND:
    case ZERO_EXTEND:
      switch (GET_MODE (XEXP (x, 0)))
        {
        case QImode:
        case HImode:
          if (GET_CODE (XEXP (x, 0)) == MEM)
            {
              *total = COSTS_N_INSNS (2);

              if (!TARGET_LITTLE_ENDIAN &&
                  side_effects_p (XEXP (XEXP (x, 0), 0)))
                *total = 100;
            }
          else
            *total = COSTS_N_INSNS (1);
          break;

        default:
          *total = COSTS_N_INSNS (1);
          break;
        }
      return true;

    default:
      return false;
    }
}

/* Implement TARGET_ADDRESS_COST macro.  */
int
score_address_cost (rtx addr,
                    bool speed ATTRIBUTE_UNUSED)
{
  return score_address_insns (addr, SImode);
}

/* Implement ASM_OUTPUT_EXTERNAL macro.  */
int
score_output_external (FILE *file ATTRIBUTE_UNUSED,
                       tree decl, const char *name)
{
  register struct extern_list *p;

  if (score_in_small_data_p (decl))
    {
      p = ggc_alloc_extern_list ();
      p->next = extern_head;
      p->name = name;
      p->size = int_size_in_bytes (TREE_TYPE (decl));
      extern_head = p;
    }
  return 0;
}

/* Implement RETURN_ADDR_RTX.  Note, we do not support moving
   back to a previous frame.  */
rtx
score_return_addr (int count, rtx frame ATTRIBUTE_UNUSED)
{
  if (count != 0)
    return const0_rtx;
  return get_hard_reg_initial_val (Pmode, RA_REGNUM);
}

/* Implement PRINT_OPERAND macro.  */
/* Score-specific operand codes:
   '['        print .set nor1 directive
   ']'        print .set r1 directive
   'U'        print hi part of a CONST_INT rtx
   'E'        print log2(v)
   'F'        print log2(~v)
   'D'        print SFmode const double
   'S'        selectively print "!" if operand is 15bit instruction accessible
   'V'        print "v!" if operand is 15bit instruction accessible, or "lfh!"
   'L'        low  part of DImode reg operand
   'H'        high part of DImode reg operand
   'C'        print part of opcode for a branch condition.  */
void
score_print_operand (FILE *file, rtx op, int c)
{
  enum rtx_code code = UNKNOWN;
  if (!PRINT_OPERAND_PUNCT_VALID_P (c))
    code = GET_CODE (op);

  if (c == '[')
    {
      fprintf (file, ".set r1\n");
    }
  else if (c == ']')
    {
      fprintf (file, "\n\t.set nor1");
    }
  else if (c == 'U')
    {
      gcc_assert (code == CONST_INT);
      fprintf (file, HOST_WIDE_INT_PRINT_HEX,
               (INTVAL (op) >> 16) & 0xffff);
    }
  else if (c == 'D')
    {
      if (GET_CODE (op) == CONST_DOUBLE)
        {
          rtx temp = gen_lowpart (SImode, op);
          gcc_assert (GET_MODE (op) == SFmode);
          fprintf (file, HOST_WIDE_INT_PRINT_HEX, INTVAL (temp) & 0xffffffff);
        }
      else
        output_addr_const (file, op);
    }
  else if (c == 'S')
    {
      gcc_assert (code == REG);
      if (G16_REG_P (REGNO (op)))
        fprintf (file, "!");
    }
  else if (c == 'V')
    {
      gcc_assert (code == REG);
      fprintf (file, G16_REG_P (REGNO (op)) ? "v!" : "lfh!");
    }
  else if (c == 'C')
    {
      enum machine_mode mode = GET_MODE (XEXP (op, 0));

      switch (code)
        {
        case EQ: fputs ("eq", file); break;
        case NE: fputs ("ne", file); break;
        case GT: fputs ("gt", file); break;
        case GE: fputs (mode != CCmode ? "pl" : "ge", file); break;
        case LT: fputs (mode != CCmode ? "mi" : "lt", file); break;
        case LE: fputs ("le", file); break;
        case GTU: fputs ("gtu", file); break;
        case GEU: fputs ("cs", file); break;
        case LTU: fputs ("cc", file); break;
        case LEU: fputs ("leu", file); break;
        default:
          output_operand_lossage ("invalid operand for code: '%c'", code);
        }
    }
  else if (c == 'E')
    {
      unsigned HOST_WIDE_INT i;
      unsigned HOST_WIDE_INT pow2mask = 1;
      unsigned HOST_WIDE_INT val;

      val = INTVAL (op);
      for (i = 0; i < 32; i++)
        {
          if (val == pow2mask)
            break;
          pow2mask <<= 1;
        }
      gcc_assert (i < 32);
      fprintf (file, HOST_WIDE_INT_PRINT_HEX, i);
    }
  else if (c == 'F')
    {
      unsigned HOST_WIDE_INT i;
      unsigned HOST_WIDE_INT pow2mask = 1;
      unsigned HOST_WIDE_INT val;

      val = ~INTVAL (op);
      for (i = 0; i < 32; i++)
        {
          if (val == pow2mask)
            break;
          pow2mask <<= 1;
        }
      gcc_assert (i < 32);
      fprintf (file, HOST_WIDE_INT_PRINT_HEX, i);
    }
  else if (code == REG)
    {
      int regnum = REGNO (op);
      if ((c == 'H' && !WORDS_BIG_ENDIAN)
          || (c == 'L' && WORDS_BIG_ENDIAN))
        regnum ++;
      fprintf (file, "%s", reg_names[regnum]);
    }
  else
    {
      switch (code)
        {
        case MEM:
          score_print_operand_address (file, op);
          break;
        default:
          output_addr_const (file, op);
        }
    }
}

/* Implement PRINT_OPERAND_ADDRESS macro.  */
void
score_print_operand_address (FILE *file, rtx x)
{
  struct score_address_info addr;
  enum rtx_code code = GET_CODE (x);
  enum machine_mode mode = GET_MODE (x);

  if (code == MEM)
    x = XEXP (x, 0);

  if (score_classify_address (&addr, mode, x, true))
    {
      switch (addr.type)
        {
        case SCORE_ADD_REG:
          {
            switch (addr.code)
              {
              case PRE_DEC:
                fprintf (file, "[%s,-%ld]+", reg_names[REGNO (addr.reg)],
                         INTVAL (addr.offset));
                break;
              case POST_DEC:
                fprintf (file, "[%s]+,-%ld", reg_names[REGNO (addr.reg)],
                         INTVAL (addr.offset));
                break;
              case PRE_INC:
                fprintf (file, "[%s, %ld]+", reg_names[REGNO (addr.reg)],
                         INTVAL (addr.offset));
                break;
              case POST_INC:
                fprintf (file, "[%s]+, %ld", reg_names[REGNO (addr.reg)],
                         INTVAL (addr.offset));
                break;
              default:
                if (INTVAL(addr.offset) == 0)
                  fprintf(file, "[%s]", reg_names[REGNO (addr.reg)]);
                else
                  fprintf(file, "[%s, %ld]", reg_names[REGNO (addr.reg)],
                          INTVAL(addr.offset));
                break;
              }
          }
          return;
        case SCORE_ADD_CONST_INT:
        case SCORE_ADD_SYMBOLIC:
          output_addr_const (file, x);
          return;
        }
    }
  print_rtl (stderr, x);
  gcc_unreachable ();
}

/* Implement SELECT_CC_MODE macro.  */
enum machine_mode
score_select_cc_mode (enum rtx_code op, rtx x, rtx y)
{
  if ((op == EQ || op == NE || op == LT || op == GE)
      && y == const0_rtx
      && GET_MODE (x) == SImode)
    {
      switch (GET_CODE (x))
        {
        case PLUS:
        case MINUS:
        case NEG:
        case AND:
        case IOR:
        case XOR:
        case NOT:
        case ASHIFT:
        case LSHIFTRT:
        case ASHIFTRT:
          return CC_NZmode;

        case SIGN_EXTEND:
        case ZERO_EXTEND:
        case ROTATE:
        case ROTATERT:
          return (op == LT || op == GE) ? CC_Nmode : CCmode;

        default:
          return CCmode;
        }
    }

  if ((op == EQ || op == NE)
      && (GET_CODE (y) == NEG)
      && register_operand (XEXP (y, 0), SImode)
      && register_operand (x, SImode))
    {
      return CC_NZmode;
    }

  return CCmode;
}

/* Generate the prologue instructions for entry into a S+core function.  */
void
score_prologue (void)
{
#define EMIT_PL(_rtx)        RTX_FRAME_RELATED_P (_rtx) = 1

  struct score_frame_info *f = score_compute_frame_size (get_frame_size ());
  HOST_WIDE_INT size;
  int regno;

  size = f->total_size - f->gp_reg_size;

  if (flag_pic)
    emit_insn (gen_cpload_score7 ());

  for (regno = (int) GP_REG_LAST; regno >= (int) GP_REG_FIRST; regno--)
    {
      if (BITSET_P (f->mask, regno - GP_REG_FIRST))
        {
          rtx mem = gen_rtx_MEM (SImode,
                                 gen_rtx_PRE_DEC (SImode, stack_pointer_rtx));
          rtx reg = gen_rtx_REG (SImode, regno);
          if (!crtl->calls_eh_return)
            MEM_READONLY_P (mem) = 1;
          EMIT_PL (emit_insn (gen_pushsi_score7 (mem, reg)));
        }
    }

  if (size > 0)
    {
      rtx insn;

      if (size >= -32768 && size <= 32767)
        EMIT_PL (emit_insn (gen_add3_insn (stack_pointer_rtx,
                                           stack_pointer_rtx,
                                           GEN_INT (-size))));
      else
        {
          EMIT_PL (emit_move_insn (gen_rtx_REG (Pmode, SCORE_PROLOGUE_TEMP_REGNUM),
                                   GEN_INT (size)));
          EMIT_PL (emit_insn
                   (gen_sub3_insn (stack_pointer_rtx,
                                   stack_pointer_rtx,
                                   gen_rtx_REG (Pmode,
                                                SCORE_PROLOGUE_TEMP_REGNUM))));
        }
      insn = get_last_insn ();
      REG_NOTES (insn) =
        alloc_EXPR_LIST (REG_FRAME_RELATED_EXPR,
                         gen_rtx_SET (VOIDmode, stack_pointer_rtx,
                                      plus_constant (Pmode, stack_pointer_rtx,
                                                     -size)),
                                      REG_NOTES (insn));
    }

  if (frame_pointer_needed)
    EMIT_PL (emit_move_insn (hard_frame_pointer_rtx, stack_pointer_rtx));

  if (flag_pic && f->cprestore_size)
    {
      if (frame_pointer_needed)
        emit_insn (gen_cprestore_use_fp_score7 (GEN_INT (size - f->cprestore_size)));
      else
        emit_insn (gen_cprestore_use_sp_score7 (GEN_INT (size - f->cprestore_size)));
    }

#undef EMIT_PL
}

/* Generate the epilogue instructions in a S+core function.  */
void
score_epilogue (int sibcall_p)
{
  struct score_frame_info *f = score_compute_frame_size (get_frame_size ());
  HOST_WIDE_INT size;
  int regno;
  rtx base;

  size = f->total_size - f->gp_reg_size;

  if (!frame_pointer_needed)
    base = stack_pointer_rtx;
  else
    base = hard_frame_pointer_rtx;

  if (size)
    {
      if (size >= -32768 && size <= 32767)
        emit_insn (gen_add3_insn (base, base, GEN_INT (size)));
      else
        {
          emit_move_insn (gen_rtx_REG (Pmode, SCORE_EPILOGUE_TEMP_REGNUM),
                          GEN_INT (size));
          emit_insn (gen_add3_insn (base, base,
                                    gen_rtx_REG (Pmode,
                                                 SCORE_EPILOGUE_TEMP_REGNUM)));
        }
    }

  if (base != stack_pointer_rtx)
    emit_move_insn (stack_pointer_rtx, base);

  if (crtl->calls_eh_return)
    emit_insn (gen_add3_insn (stack_pointer_rtx,
                              stack_pointer_rtx,
                              EH_RETURN_STACKADJ_RTX));

  for (regno = (int) GP_REG_FIRST; regno <= (int) GP_REG_LAST; regno++)
    {
      if (BITSET_P (f->mask, regno - GP_REG_FIRST))
        {
          rtx mem = gen_rtx_MEM (SImode,
                                 gen_rtx_POST_INC (SImode, stack_pointer_rtx));
          rtx reg = gen_rtx_REG (SImode, regno);

          if (!crtl->calls_eh_return)
            MEM_READONLY_P (mem) = 1;

          emit_insn (gen_popsi_score7 (reg, mem));
        }
    }

  if (!sibcall_p)
    emit_jump_insn (gen_return_internal_score7 (gen_rtx_REG (Pmode, RA_REGNUM)));
}

/* Return true if X is a symbolic constant that can be calculated in
   the same way as a bare symbol.  If it is, store the type of the
   symbol in *SYMBOL_TYPE.  */
int
score_symbolic_constant_p (rtx x, enum score_symbol_type *symbol_type)
{
  HOST_WIDE_INT offset;

  score_split_const (x, &x, &offset);
  if (GET_CODE (x) == SYMBOL_REF || GET_CODE (x) == LABEL_REF)
    *symbol_type = score_classify_symbol (x);
  else
    return 0;

  if (offset == 0)
    return 1;

  /* if offset > 15bit, must reload  */
  if (!IMM_IN_RANGE (offset, 15, 1))
    return 0;

  switch (*symbol_type)
    {
    case SYMBOL_GENERAL:
      return 1;
    case SYMBOL_SMALL_DATA:
      return score_offset_within_object_p (x, offset);
    }
  gcc_unreachable ();
}

void
score_movsicc (rtx *ops)
{
  enum machine_mode mode;

  mode = score_select_cc_mode (GET_CODE (ops[1]), ops[2], ops[3]);
  emit_insn (gen_rtx_SET (VOIDmode, gen_rtx_REG (mode, CC_REGNUM),
                          gen_rtx_COMPARE (mode, XEXP (ops[1], 0),
                                           XEXP (ops[1], 1))));
}

/* Call and sibcall pattern all need call this function.  */
void
score_call (rtx *ops, bool sib)
{
  rtx addr = XEXP (ops[0], 0);
  if (!call_insn_operand (addr, VOIDmode))
    {
      rtx oaddr = addr;
      addr = gen_reg_rtx (Pmode);
      gen_move_insn (addr, oaddr);
    }

  if (sib)
    emit_call_insn (gen_sibcall_internal_score7 (addr, ops[1]));
  else
    emit_call_insn (gen_call_internal_score7 (addr, ops[1]));
}

/* Call value and sibcall value pattern all need call this function.  */
void
score_call_value (rtx *ops, bool sib)
{
  rtx result = ops[0];
  rtx addr = XEXP (ops[1], 0);
  rtx arg = ops[2];

  if (!call_insn_operand (addr, VOIDmode))
    {
      rtx oaddr = addr;
      addr = gen_reg_rtx (Pmode);
      gen_move_insn (addr, oaddr);
    }

  if (sib)
    emit_call_insn (gen_sibcall_value_internal_score7 (result, addr, arg));
  else
    emit_call_insn (gen_call_value_internal_score7 (result, addr, arg));
}

/* Machine Split  */
void
score_movdi (rtx *ops)
{
  rtx dst = ops[0];
  rtx src = ops[1];
  rtx dst0 = score_subw (dst, 0);
  rtx dst1 = score_subw (dst, 1);
  rtx src0 = score_subw (src, 0);
  rtx src1 = score_subw (src, 1);

  if (GET_CODE (dst0) == REG && reg_overlap_mentioned_p (dst0, src))
    {
      emit_move_insn (dst1, src1);
      emit_move_insn (dst0, src0);
    }
  else
    {
      emit_move_insn (dst0, src0);
      emit_move_insn (dst1, src1);
    }
}

void
score_zero_extract_andi (rtx *ops)
{
  if (INTVAL (ops[1]) == 1 && const_uimm5 (ops[2], SImode))
    emit_insn (gen_zero_extract_bittst_score7 (ops[0], ops[2]));
  else
    {
      unsigned HOST_WIDE_INT mask;
      mask = (0xffffffffU & ((1U << INTVAL (ops[1])) - 1U));
      mask = mask << INTVAL (ops[2]);
      emit_insn (gen_andsi3_cmp_score7 (ops[3], ops[0],
                                 gen_int_mode (mask, SImode)));
    }
}

/* Check addr could be present as PRE/POST mode.  */
static bool
score_pindex_mem (rtx addr)
{
  if (GET_CODE (addr) == MEM)
    {
      switch (GET_CODE (XEXP (addr, 0)))
        {
        case PRE_DEC:
        case POST_DEC:
        case PRE_INC:
        case POST_INC:
          return true;
        default:
          break;
        }
    }
  return false;
}

/* Output asm code for ld/sw insn.  */
static int
score_pr_addr_post (rtx *ops, int idata, int iaddr, char *ip, enum score_mem_unit unit)
{
  struct score_address_info ai;

  gcc_assert (GET_CODE (ops[idata]) == REG);
  gcc_assert (score_classify_address (&ai, SImode, XEXP (ops[iaddr], 0), true));

  if (!score_pindex_mem (ops[iaddr])
      && ai.type == SCORE_ADD_REG
      && GET_CODE (ai.offset) == CONST_INT
      && G16_REG_P (REGNO (ops[idata]))
      && G16_REG_P (REGNO (ai.reg)))
    {
      if (INTVAL (ai.offset) == 0)
        {
          ops[iaddr] = ai.reg;
          return snprintf (ip, INS_BUF_SZ,
                           "!\t%%%d, [%%%d]", idata, iaddr);
        }
      if (REGNO (ai.reg) == HARD_FRAME_POINTER_REGNUM)
        {
          HOST_WIDE_INT offset = INTVAL (ai.offset);
          if (SCORE_ALIGN_UNIT (offset, unit)
              && (((offset >> unit) >= 0) && ((offset >> unit) <= 31)))
            {
              ops[iaddr] = ai.offset;
              return snprintf (ip, INS_BUF_SZ,
                               "p!\t%%%d, %%c%d", idata, iaddr);
            }
        }
    }
  return snprintf (ip, INS_BUF_SZ, "\t%%%d, %%a%d", idata, iaddr);
}

/* Output asm insn for load.  */
const char *
score_linsn (rtx *ops, enum score_mem_unit unit, bool sign)
{
  const char *pre_ins[] =
    {"lbu", "lhu", "lw", "??", "lb", "lh", "lw", "??"};
  char *ip;

  strcpy (score_ins, pre_ins[(sign ? 4 : 0) + unit]);
  ip = score_ins + strlen (score_ins);

  if ((!sign && unit != SCORE_HWORD)
      || (sign && unit != SCORE_BYTE))
    score_pr_addr_post (ops, 0, 1, ip, unit);
  else
    snprintf (ip, INS_BUF_SZ, "\t%%0, %%a1");

  return score_ins;
}

/* Output asm insn for store.  */
const char *
score_sinsn (rtx *ops, enum score_mem_unit unit)
{
  const char *pre_ins[] = {"sb", "sh", "sw"};
  char *ip;

  strcpy (score_ins, pre_ins[unit]);
  ip = score_ins + strlen (score_ins);
  score_pr_addr_post (ops, 1, 0, ip, unit);
  return score_ins;
}

/* Output asm insn for load immediate.  */
const char *
score_limm (rtx *ops)
{
  HOST_WIDE_INT v;

  gcc_assert (GET_CODE (ops[0]) == REG);
  gcc_assert (GET_CODE (ops[1]) == CONST_INT);

  v = INTVAL (ops[1]);
  if (G16_REG_P (REGNO (ops[0])) && IMM_IN_RANGE (v, 8, 0))
    return "ldiu!\t%0, %c1";
  else if (IMM_IN_RANGE (v, 16, 1))
    return "ldi\t%0, %c1";
  else if ((v & 0xffff) == 0)
    return "ldis\t%0, %U1";
  else
    return "li\t%0, %c1";
}

/* Output asm insn for move.  */
const char *
score_move (rtx *ops)
{
  gcc_assert (GET_CODE (ops[0]) == REG);
  gcc_assert (GET_CODE (ops[1]) == REG);

  if (G16_REG_P (REGNO (ops[0])))
    {
      if (G16_REG_P (REGNO (ops[1])))
        return "mv!\t%0, %1";
      else
        return "mlfh!\t%0, %1";
    }
  else if (G16_REG_P (REGNO (ops[1])))
    return "mhfl!\t%0, %1";
  else
    return "mv\t%0, %1";
}

/* Generate add insn.  */
const char *
score_select_add_imm (rtx *ops, bool set_cc)
{
  HOST_WIDE_INT v = INTVAL (ops[2]);

  gcc_assert (GET_CODE (ops[2]) == CONST_INT);
  gcc_assert (REGNO (ops[0]) == REGNO (ops[1]));

  if (set_cc && G16_REG_P (REGNO (ops[0])))
    {
      if (v > 0 && IMM_IS_POW_OF_2 ((unsigned HOST_WIDE_INT) v, 0, 15))
        {
          ops[2] = GEN_INT (ffs (v) - 1);
          return "addei!\t%0, %c2";
        }

      if (v < 0 && IMM_IS_POW_OF_2 ((unsigned HOST_WIDE_INT) (-v), 0, 15))
        {
          ops[2] = GEN_INT (ffs (-v) - 1);
          return "subei!\t%0, %c2";
        }
    }

  if (set_cc)
    return "addi.c\t%0, %c2";
  else
    return "addi\t%0, %c2";
}

/* Output arith insn.  */
const char *
score_select (rtx *ops, const char *inst_pre,
              bool commu, const char *letter, bool set_cc)
{
  gcc_assert (GET_CODE (ops[0]) == REG);
  gcc_assert (GET_CODE (ops[1]) == REG);

  if (set_cc && G16_REG_P (REGNO (ops[0]))
      && (GET_CODE (ops[2]) == REG ? G16_REG_P (REGNO (ops[2])) : 1)
      && REGNO (ops[0]) == REGNO (ops[1]))
    {
      snprintf (score_ins, INS_BUF_SZ, "%s!\t%%0, %%%s2", inst_pre, letter);
      return score_ins;
    }

  if (commu && set_cc && G16_REG_P (REGNO (ops[0]))
      && G16_REG_P (REGNO (ops[1]))
      && REGNO (ops[0]) == REGNO (ops[2]))
    {
      gcc_assert (GET_CODE (ops[2]) == REG);
      snprintf (score_ins, INS_BUF_SZ, "%s!\t%%0, %%%s1", inst_pre, letter);
      return score_ins;
    }

  if (set_cc)
    snprintf (score_ins, INS_BUF_SZ, "%s.c\t%%0, %%1, %%%s2", inst_pre, letter);
  else
    snprintf (score_ins, INS_BUF_SZ, "%s\t%%0, %%1, %%%s2", inst_pre, letter);
  return score_ins;
}

/* Return nonzero when an argument must be passed by reference.  */
static bool
score_pass_by_reference (cumulative_args_t cum ATTRIBUTE_UNUSED,
                         enum machine_mode mode, const_tree type,
                         bool named ATTRIBUTE_UNUSED)
{
  /* If we have a variable-sized parameter, we have no choice.  */
  return targetm.calls.must_pass_in_stack (mode, type);
}

/* Implement TARGET_FUNCTION_OK_FOR_SIBCALL.  */
static bool
score_function_ok_for_sibcall (ATTRIBUTE_UNUSED tree decl,
                               ATTRIBUTE_UNUSED tree exp)
{
  return true;
}

/* Implement TARGET_SCHED_ISSUE_RATE.  */
static int
score_issue_rate (void)
{
  return 1;
}

/* We can always eliminate to the hard frame pointer.  We can eliminate
   to the stack pointer unless a frame pointer is needed.  */

static bool
score_can_eliminate (const int from ATTRIBUTE_UNUSED, const int to)
{
  return (to == HARD_FRAME_POINTER_REGNUM
          || (to  == STACK_POINTER_REGNUM && !frame_pointer_needed));
}

/* Argument support functions.  */

/* Initialize CUMULATIVE_ARGS for a function.  */
void
score_init_cumulative_args (CUMULATIVE_ARGS *cum,
                            tree fntype ATTRIBUTE_UNUSED,
                            rtx libname ATTRIBUTE_UNUSED)
{
  memset (cum, 0, sizeof (CUMULATIVE_ARGS));
}

static void
score_conditional_register_usage (void)
{
   if (!flag_pic)
     fixed_regs[PIC_OFFSET_TABLE_REGNUM] =
     call_used_regs[PIC_OFFSET_TABLE_REGNUM] = 0;
}

struct gcc_target targetm = TARGET_INITIALIZER;