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/* Target Code for moxie

   Copyright (C) 2008, 2009, 2010  Free Software Foundation

   Contributed by Anthony Green.

   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 "real.h"

#include "insn-config.h"

#include "conditions.h"

#include "insn-flags.h"

#include "output.h"

#include "insn-attr.h"

#include "flags.h"

#include "recog.h"

#include "reload.h"

#include "toplev.h"

#include "obstack.h"

#include "tree.h"

#include "expr.h"

#include "optabs.h"

#include "except.h"

#include "function.h"

#include "ggc.h"

#include "target.h"

#include "target-def.h"

#include "tm_p.h"

#include "langhooks.h"

#include "df.h"

#define LOSE_AND_RETURN(msgid, x)               \

  do                                            \

    {                                           \

      moxie_operand_lossage (msgid, x);         \

      return;                                   \

    } while (0)

/* Worker function for TARGET_RETURN_IN_MEMORY.  */

static bool

moxie_return_in_memory (const_tree type, const_tree fntype ATTRIBUTE_UNUSED)

{

  const HOST_WIDE_INT size = int_size_in_bytes (type);

  return (size == -1 || size > 2 * UNITS_PER_WORD);

}

/* Define how to find the value returned by a function.

   VALTYPE is the data type of the value (as a tree).

   If the precise function being called is known, FUNC is its

   FUNCTION_DECL; otherwise, FUNC is 0.

   We always return values in register $r0 for moxie.  */

rtx

moxie_function_value (const_tree valtype,

                      const_tree fntype_or_decl ATTRIBUTE_UNUSED,

                      bool outgoing ATTRIBUTE_UNUSED)

{

  return gen_rtx_REG (TYPE_MODE (valtype), MOXIE_R0);

}

/* Emit an error message when we're in an asm, and a fatal error for

   "normal" insns.  Formatted output isn't easily implemented, since we

   use output_operand_lossage to output the actual message and handle the

   categorization of the error.  */

static void

moxie_operand_lossage (const char *msgid, rtx op)

{

  debug_rtx (op);

  output_operand_lossage ("%s", msgid);

}

/* The PRINT_OPERAND_ADDRESS worker.  */

void

moxie_print_operand_address (FILE *file, rtx x)

{

  switch (GET_CODE (x))

    {

    case REG:

      fprintf (file, "(%s)", reg_names[REGNO (x)]);

      break;

    case PLUS:

      switch (GET_CODE (XEXP (x, 1)))

        {

        case CONST_INT:

          fprintf (file, "%ld(%s)",

                   INTVAL(XEXP (x, 1)), reg_names[REGNO (XEXP (x, 0))]);

          break;

        case SYMBOL_REF:

          output_addr_const (file, XEXP (x, 1));

          fprintf (file, "(%s)", reg_names[REGNO (XEXP (x, 0))]);

          break;

        case CONST:

          {

            rtx plus = XEXP (XEXP (x, 1), 0);

            if (GET_CODE (XEXP (plus, 0)) == SYMBOL_REF

                && CONST_INT_P (XEXP (plus, 1)))

              {

                output_addr_const(file, XEXP (plus, 0));

                fprintf (file,"+%ld(%s)", INTVAL (XEXP (plus, 1)),

                         reg_names[REGNO (XEXP (x, 0))]);

              }

            else

              abort();

          }

          break;

        default:

          abort();

        }

      break;

    default:

      output_addr_const (file, x);

      break;

    }

}

/* The PRINT_OPERAND worker.  */

void

moxie_print_operand (FILE *file, rtx x, int code)

{

  rtx operand = x;

  /* New code entries should just be added to the switch below.  If

     handling is finished, just return.  If handling was just a

     modification of the operand, the modified operand should be put in

     "operand", and then do a break to let default handling

     (zero-modifier) output the operand.  */

  switch (code)

    {

    case 0:

      /* No code, print as usual.  */

      break;

    default:

      LOSE_AND_RETURN ("invalid operand modifier letter", x);

    }

  /* Print an operand as without a modifier letter.  */

  switch (GET_CODE (operand))

    {

    case REG:

      if (REGNO (operand) > MOXIE_R13)

        internal_error ("internal error: bad register: %d", REGNO (operand));

      fprintf (file, "%s", reg_names[REGNO (operand)]);

      return;

    case MEM:

      output_address (XEXP (operand, 0));

      return;

    default:

      /* No need to handle all strange variants, let output_addr_const

         do it for us.  */

      if (CONSTANT_P (operand))

        {

          output_addr_const (file, operand);

          return;

        }

      LOSE_AND_RETURN ("unexpected operand", x);

    }

}

/* Per-function machine data.  */

struct GTY(()) machine_function

 {

   /* Number of bytes saved on the stack for callee saved registers.  */

   int callee_saved_reg_size;

   /* Number of bytes saved on the stack for local variables.  */

   int local_vars_size;

   /* The sum of 2 sizes: locals vars and padding byte for saving the

    * registers.  Used in expand_prologue () and expand_epilogue().  */

   int size_for_adjusting_sp;

 };

/* Zero initialization is OK for all current fields.  */

static struct machine_function *

moxie_init_machine_status (void)

{

  return GGC_CNEW (struct machine_function);

}

/* The OVERRIDE_OPTIONS worker.

   All this curently does is set init_machine_status.  */

void

moxie_override_options (void)

{

  /* Set the per-function-data initializer.  */

  init_machine_status = moxie_init_machine_status;

}

/* Compute the size of the local area and the size to be adjusted by the

 * prologue and epilogue.  */

static void

moxie_compute_frame (void)

{

  /* For aligning the local variables.  */

  int stack_alignment = STACK_BOUNDARY / BITS_PER_UNIT;

  int padding_locals;

  int regno;

  /* Padding needed for each element of the frame.  */

  cfun->machine->local_vars_size = get_frame_size ();

  /* Align to the stack alignment.  */

  padding_locals = cfun->machine->local_vars_size % stack_alignment;

  if (padding_locals)

    padding_locals = stack_alignment - padding_locals;

  cfun->machine->local_vars_size += padding_locals;

  cfun->machine->callee_saved_reg_size = 0;

  /* Save callee-saved registers.  */

  for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)

    if (df_regs_ever_live_p (regno) && (! call_used_regs[regno]))

      cfun->machine->callee_saved_reg_size += 4;

  cfun->machine->size_for_adjusting_sp =

    crtl->args.pretend_args_size

    + cfun->machine->local_vars_size

    + (ACCUMULATE_OUTGOING_ARGS ? crtl->outgoing_args_size : 0);

}

void

moxie_expand_prologue (void)

{

  int regno;

  rtx insn;

  moxie_compute_frame ();

  /* Save callee-saved registers.  */

  for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)

    {

      if (!fixed_regs[regno] && df_regs_ever_live_p (regno) && !call_used_regs[regno])

        {

          insn = emit_insn (gen_movsi_push (gen_rtx_REG (Pmode, regno)));

          RTX_FRAME_RELATED_P (insn) = 1;

        }

    }

  if (cfun->machine->size_for_adjusting_sp > 0)

    {

      int i = cfun->machine->size_for_adjusting_sp;

      while (i > 255)

        {

          insn = emit_insn (gen_subsi3 (stack_pointer_rtx,

                                        stack_pointer_rtx,

                                        GEN_INT (255)));

          RTX_FRAME_RELATED_P (insn) = 1;

          i -= 255;

        }

      if (i > 0)

        {

          insn = emit_insn (gen_subsi3 (stack_pointer_rtx,

                                        stack_pointer_rtx,

                                        GEN_INT (i)));

          RTX_FRAME_RELATED_P (insn) = 1;

        }

    }

}

void

moxie_expand_epilogue (void)

{

  int regno;

  rtx insn, reg, cfa_restores = NULL;

  if (cfun->machine->callee_saved_reg_size != 0)

    {

      reg = gen_rtx_REG (Pmode, MOXIE_R5);

      if (cfun->machine->callee_saved_reg_size <= 255)

        {

          emit_move_insn (reg, hard_frame_pointer_rtx);

          emit_insn (gen_subsi3

                     (reg, reg,

                      GEN_INT (cfun->machine->callee_saved_reg_size)));

        }

      else

        {

          emit_move_insn (reg,

                          GEN_INT (-cfun->machine->callee_saved_reg_size));

          emit_insn (gen_addsi3 (reg, reg, hard_frame_pointer_rtx));

        }

      for (regno = FIRST_PSEUDO_REGISTER; regno-- > 0; )

        if (!fixed_regs[regno] && !call_used_regs[regno]

            && df_regs_ever_live_p (regno))

          {

            rtx preg = gen_rtx_REG (Pmode, regno);

            insn = emit_insn (gen_movsi_pop (reg, preg));

          }

    }

  emit_jump_insn (gen_returner ());

}

/* Implements the macro INITIAL_ELIMINATION_OFFSET, return the OFFSET.  */

int

moxie_initial_elimination_offset (int from, int to)

{

  int ret;

  if ((from) == FRAME_POINTER_REGNUM && (to) == HARD_FRAME_POINTER_REGNUM)

    {

      /* Compute this since we need to use cfun->machine->local_vars_size.  */

      moxie_compute_frame ();

      ret = -cfun->machine->callee_saved_reg_size;

    }

  else if ((from) == ARG_POINTER_REGNUM && (to) == HARD_FRAME_POINTER_REGNUM)

    ret = 0x00;

  else

    abort ();

  return ret;

}

/* Worker function for TARGET_SETUP_INCOMING_VARARGS.  */

static void

moxie_setup_incoming_varargs (CUMULATIVE_ARGS *cum,

                              enum machine_mode mode ATTRIBUTE_UNUSED,

                              tree type ATTRIBUTE_UNUSED,

                              int *pretend_size, int no_rtl)

{

  int regno;

  int regs = 8 - *cum;

  *pretend_size = regs < 0 ? 0 : GET_MODE_SIZE (SImode) * regs;

  if (no_rtl)

    return;

  for (regno = *cum; regno < 8; regno++)

    {

      rtx reg = gen_rtx_REG (SImode, regno);

      rtx slot = gen_rtx_PLUS (Pmode,

                               gen_rtx_REG (SImode, ARG_POINTER_REGNUM),

                               GEN_INT (UNITS_PER_WORD * (3 + (regno-2))));

      emit_move_insn (gen_rtx_MEM (SImode, slot), reg);

    }

}

/* Return the fixed registers used for condition codes.  */

static bool

moxie_fixed_condition_code_regs (unsigned int *p1, unsigned int *p2)

{

  *p1 = CC_REG;

  *p2 = INVALID_REGNUM;

  return true;

}

/* Return the next register to be used to hold a function argument or

   NULL_RTX if there's no more space.  */

rtx

moxie_function_arg (CUMULATIVE_ARGS cum, enum machine_mode mode,

                    tree type ATTRIBUTE_UNUSED, int named ATTRIBUTE_UNUSED)

{

  if (cum < 8)

    return gen_rtx_REG (mode, cum);

  else

    return NULL_RTX;

}

/* Return non-zero if the function argument described by TYPE is to be

   passed by reference.  */

static bool

moxie_pass_by_reference (CUMULATIVE_ARGS *cum ATTRIBUTE_UNUSED,

                         enum machine_mode mode, const_tree type,

                         bool named ATTRIBUTE_UNUSED)

{

  unsigned HOST_WIDE_INT size;

  if (type)

    {

      if (AGGREGATE_TYPE_P (type))

        return true;

      size = int_size_in_bytes (type);

    }

  else

    size = GET_MODE_SIZE (mode);

  return size > 4*6;

}

/* Some function arguments will only partially fit in the registers

   that hold arguments.  Given a new arg, return the number of bytes

   that fit in argument passing registers.  */

static int

moxie_arg_partial_bytes (CUMULATIVE_ARGS *cum,

                         enum machine_mode mode,

                         tree type, bool named)

{

  int bytes_left, size;

  if (*cum >= 8)

    return 0;

  if (moxie_pass_by_reference (cum, mode, type, named))

    size = 4;

  else if (type)

    {

      if (AGGREGATE_TYPE_P (type))

        return 0;

      size = int_size_in_bytes (type);

    }

  else

    size = GET_MODE_SIZE (mode);

  bytes_left = (4 * 6) - ((*cum - 2) * 4);

  if (size > bytes_left)

    return bytes_left;

  else

    return 0;

}

/* Worker function for TARGET_STATIC_CHAIN.  */

static rtx

moxie_static_chain (const_tree fndecl, bool incoming_p)

{

  rtx addr, mem;

  if (!DECL_STATIC_CHAIN (fndecl))

    return NULL;

  if (incoming_p)

    addr = plus_constant (arg_pointer_rtx, 2 * UNITS_PER_WORD);

  else

    addr = plus_constant (stack_pointer_rtx, -UNITS_PER_WORD);

  mem = gen_rtx_MEM (Pmode, addr);

  MEM_NOTRAP_P (mem) = 1;

  return mem;

}

/* Worker function for TARGET_ASM_TRAMPOLINE_TEMPLATE.  */

static void

moxie_asm_trampoline_template (FILE *f)

{

  fprintf (f, "\tpush  $sp, $r0\n");

  fprintf (f, "\tldi.l $r0, 0x0\n");

  fprintf (f, "\tsto.l 0x8($fp), $r0\n");

  fprintf (f, "\tpop   $sp, $r0\n");

  fprintf (f, "\tnop\n");

  fprintf (f, "\tjmpa  0x0\n");

}

/* Worker function for TARGET_TRAMPOLINE_INIT.  */

static void

moxie_trampoline_init (rtx m_tramp, tree fndecl, rtx chain_value)

{

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

  emit_block_move (m_tramp, assemble_trampoline_template (),

                   GEN_INT (TRAMPOLINE_SIZE), BLOCK_OP_NORMAL);

  mem = adjust_address (m_tramp, SImode, 4);

  emit_move_insn (mem, chain_value);

  mem = adjust_address (m_tramp, SImode, 20);

  emit_move_insn (mem, fnaddr);

}

/* The Global `targetm' Variable.  */

/* Initialize the GCC target structure.  */

#undef  TARGET_PROMOTE_PROTOTYPES

#define TARGET_PROMOTE_PROTOTYPES       hook_bool_const_tree_true

#undef  TARGET_RETURN_IN_MEMORY

#define TARGET_RETURN_IN_MEMORY         moxie_return_in_memory

#undef  TARGET_MUST_PASS_IN_STACK

#define TARGET_MUST_PASS_IN_STACK       must_pass_in_stack_var_size

#undef  TARGET_PASS_BY_REFERENCE

#define TARGET_PASS_BY_REFERENCE        moxie_pass_by_reference

#undef  TARGET_ARG_PARTIAL_BYTES

#define TARGET_ARG_PARTIAL_BYTES        moxie_arg_partial_bytes

#undef  TARGET_SETUP_INCOMING_VARARGS

#define TARGET_SETUP_INCOMING_VARARGS   moxie_setup_incoming_varargs

#undef  TARGET_FIXED_CONDITION_CODE_REGS

#define TARGET_FIXED_CONDITION_CODE_REGS moxie_fixed_condition_code_regs

/* Define this to return an RTX representing the place where a

   function returns or receives a value of data type RET_TYPE, a tree

   node node representing a data type.  */

#undef TARGET_FUNCTION_VALUE

#define TARGET_FUNCTION_VALUE moxie_function_value

#undef TARGET_FRAME_POINTER_REQUIRED

#define TARGET_FRAME_POINTER_REQUIRED hook_bool_void_true

#undef TARGET_STATIC_CHAIN

#define TARGET_STATIC_CHAIN moxie_static_chain

#undef TARGET_ASM_TRAMPOLINE_TEMPLATE

#define TARGET_ASM_TRAMPOLINE_TEMPLATE moxie_asm_trampoline_template

#undef TARGET_TRAMPOLINE_INIT

#define TARGET_TRAMPOLINE_INIT moxie_trampoline_init

struct gcc_target targetm = TARGET_INITIALIZER;

#include "gt-moxie.h"