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[thirdparty/gcc.git] / gcc / config / msp430 / msp430.cc

/* Subroutines used for code generation on TI MSP430 processors.
   Copyright (C) 2012-2023 Free Software Foundation, Inc.
   Contributed by Red Hat.

   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/>.  */

#define IN_TARGET_CODE 1

#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "backend.h"
#include "target.h"
#include "rtl.h"
#include "tree.h"
#include "stringpool.h"
#include "attribs.h"
#include "gimple-expr.h"
#include "df.h"
#include "memmodel.h"
#include "tm_p.h"
#include "regs.h"
#include "emit-rtl.h"
#include "varasm.h"
#include "diagnostic-core.h"
#include "fold-const.h"
#include "stor-layout.h"
#include "calls.h"
#include "output.h"
#include "explow.h"
#include "expr.h"
#include "langhooks.h"
#include "builtins.h"
#include "intl.h"
#include "msp430-devices.h"
#include "incpath.h"
#include "prefix.h"
#include "insn-config.h"
#include "insn-attr.h"
#include "recog.h"

/* This file should be included last.  */
#include "target-def.h"
\f

static void msp430_compute_frame_info (void);
static bool msp430_use_16bit_hwmult (void);
static bool msp430_use_32bit_hwmult (void);
static bool use_helper_for_const_shift (machine_mode mode, HOST_WIDE_INT amt);

\f

/* Run-time Target Specification.  */

bool msp430x = true;

struct GTY(()) machine_function
{
  /* If set, the rest of the fields have been computed.  */
  int computed;
  /* Which registers need to be saved in the pro/epilogue.  */
  int need_to_save[FIRST_PSEUDO_REGISTER];

  /* These fields describe the frame layout...  */
  /* arg pointer */
  /* 2/4 bytes for saved PC */
  int framesize_regs;
  /* frame pointer */
  int framesize_locals;
  int framesize_outgoing;
  /* stack pointer */
  int framesize;

  /* How much we adjust the stack when returning from an exception
     handler.  */
  rtx eh_stack_adjust;
};

/* This is our init_machine_status, as set in
   msp430_option_override.  */
static struct machine_function *
msp430_init_machine_status (void)
{
  struct machine_function *m;

  m = ggc_cleared_alloc<machine_function> ();

  return m;
}

#undef  TARGET_OPTION_OVERRIDE
#define TARGET_OPTION_OVERRIDE          msp430_option_override

/* Generate a C preprocessor symbol based upon the MCU selected by the user.
   If a specific MCU has not been selected then return a generic symbol
   instead.  */

const char *
msp430_mcu_name (void)
{
  if (target_mcu)
    {
      msp430_extract_mcu_data (target_mcu);
      unsigned int i;
      unsigned int start_upper;
      unsigned int end_upper;
      static char mcu_name[64];

      /* The 'i' in the device name symbol for msp430i* devices must be lower
         case, to match the expected symbol in msp430.h.  */
      if (startswith (target_mcu, "msp430i"))
        {
          snprintf (mcu_name, sizeof (mcu_name) - 1, "__MSP430i%s__",
                    target_mcu + 7);
          start_upper = 9;
        }
      else
        {
          snprintf (mcu_name, sizeof (mcu_name) - 1, "__%s__", target_mcu);
          start_upper = 2;
        }
      end_upper = strlen (mcu_name) - 2;
      for (i = start_upper; i < end_upper; i++)
        mcu_name[i] = TOUPPER (mcu_name[i]);
      return mcu_name;
    }

  return msp430x ? "__MSP430XGENERIC__" : "__MSP430GENERIC__";
}

static const char *
hwmult_name (unsigned int val)
{
  switch (val)
    {
    case 0: return "none";
    case 1: return "16-bit";
    case 2: return "16-bit";
    case 4: return "32-bit";
    case 8: return "32-bit (5xx)";
    default: gcc_unreachable ();
    }
}

static void
msp430_option_override (void)
{
  /* The MSP430 architecture can safely dereference a NULL pointer.  In fact,
     there are memory mapped registers there.  */
  flag_delete_null_pointer_checks = 0;

  init_machine_status = msp430_init_machine_status;

  msp430x = target_cpu >= MSP430_CPU_MSP430X_DEFAULT;

  if (target_mcu)
    {
      msp430_extract_mcu_data (target_mcu);

      if (extracted_mcu_data.name != NULL)
        {
          bool xisa = extracted_mcu_data.revision >= 1;

          if (msp430_warn_mcu)
            {
              if (target_cpu != MSP430_CPU_MSP430X_DEFAULT && msp430x != xisa)
                warning (0, "MCU %qs supports %s ISA but %<-mcpu%> option "
                         "is set to %s",
                         target_mcu, xisa ? "430X" : "430",
                         msp430x ? "430X" : "430");

              if (extracted_mcu_data.hwmpy == 0
                  && msp430_hwmult_type != MSP430_HWMULT_AUTO
                  && msp430_hwmult_type != MSP430_HWMULT_NONE)
                warning (0, "MCU %qs does not have hardware multiply "
                         "support, but %<-mhwmult%> is set to %s",
                         target_mcu,
                         msp430_hwmult_type == MSP430_HWMULT_SMALL ? "16-bit"
                         : msp430_hwmult_type == MSP430_HWMULT_LARGE
                         ? "32-bit" : "f5series");
              else if (msp430_hwmult_type == MSP430_HWMULT_SMALL
                       && extracted_mcu_data.hwmpy != 1
                       && extracted_mcu_data.hwmpy != 2)
                warning (0, "MCU %qs supports %s hardware multiply, "
                         "but %<-mhwmult%> is set to 16-bit",
                         target_mcu, hwmult_name (extracted_mcu_data.hwmpy));
              else if (msp430_hwmult_type == MSP430_HWMULT_LARGE
                       && extracted_mcu_data.hwmpy != 4)
                warning (0, "MCU %qs supports %s hardware multiply, "
                         "but %<-mhwmult%> is set to 32-bit",
                         target_mcu, hwmult_name (extracted_mcu_data.hwmpy));
              else if (msp430_hwmult_type == MSP430_HWMULT_F5SERIES
                       && extracted_mcu_data.hwmpy != 8)
                warning (0, "MCU %qs supports %s hardware multiply, "
                         "but %<-mhwmult%> is set to f5series",
                         target_mcu, hwmult_name (extracted_mcu_data.hwmpy));
            }
          /* Only override the default setting with the extracted ISA value if
             the user has not passed -mcpu=.  */
          if (target_cpu == MSP430_CPU_MSP430X_DEFAULT)
            msp430x = xisa;
        }
      else
        {
          if (msp430_hwmult_type == MSP430_HWMULT_AUTO)
            {
              if (msp430_warn_mcu)
                {
                  if (target_cpu == MSP430_CPU_MSP430X_DEFAULT)
                    warning (0,
                             "unrecognized MCU name %qs, assuming that it is "
                             "just a MSP430X with no hardware multiply; "
                             "use the %<-mcpu%> and %<-mhwmult%> options to "
                             "set these explicitly",
                             target_mcu);
                  else
                    warning (0,
                             "unrecognized MCU name %qs, assuming that it "
                             "has no hardware multiply; use the %<-mhwmult%> "
                             "option to set this explicitly",
                             target_mcu);
                }

              msp430_hwmult_type = MSP430_HWMULT_NONE;
            }
          else if (target_cpu == MSP430_CPU_MSP430X_DEFAULT)
            {
              if (msp430_warn_mcu)
                warning (0,
                         "unrecognized MCU name %qs, assuming that it just "
                         "supports the MSP430X ISA; use the %<-mcpu%> option "
                         "to set the ISA explicitly",
                         target_mcu);
            }
          else if (msp430_warn_mcu)
            warning (0, "Unrecognized MCU name %qs.", target_mcu);
        }
    }

  if (TARGET_LARGE && !msp430x)
    error ("%<-mlarge%> requires a 430X-compatible %<-mmcu=%>");

  if (!TARGET_LARGE && msp430_code_region == MSP430_REGION_EITHER)
    error ("%<-mcode-region=either%> requires the large memory model "
           "(%<-mlarge%>)");
  else if (!TARGET_LARGE && msp430_code_region == MSP430_REGION_UPPER)
    error ("%<-mcode-region=upper%> requires the large memory model "
           "(%<-mlarge%>)");

  if (!TARGET_LARGE && msp430_data_region == MSP430_REGION_EITHER)
    error ("%<-mdata-region=either%> requires the large memory model "
           "(%<-mlarge%>)");
  else if (!TARGET_LARGE && msp430_data_region == MSP430_REGION_UPPER)
    error ("%<-mdata-region=upper%> requires the large memory model "
           "(%<-mlarge%>)");

  if (flag_exceptions || flag_non_call_exceptions
      || flag_unwind_tables || flag_asynchronous_unwind_tables)
    flag_omit_frame_pointer = false;
  else
    flag_omit_frame_pointer = true;

  /* This is a hack to work around a problem with the newlib build
     mechanism.  Newlib always appends CFLAGS to the end of the GCC
     command line and always sets -O2 in CFLAGS.  Thus it is not
     possible to build newlib with -Os enabled.  Until now...  */
  if (TARGET_OPT_SPACE && optimize < 3)
    optimize_size = 1;

#if !DEFAULT_USE_CXA_ATEXIT
  /* For some configurations, we use atexit () instead of __cxa_atexit () by
     default to save on code size and remove the declaration of __dso_handle
     from the CRT library.
     Configuring GCC with --enable-__cxa-atexit re-enables it by defining
     DEFAULT_USE_CXA_ATEXIT to 1.  */
  if (flag_use_cxa_atexit)
    error ("%<-fuse-cxa-atexit%> is not supported for msp430-elf");
#endif

#ifndef HAVE_NEWLIB_NANO_FORMATTED_IO
  if (TARGET_TINY_PRINTF)
    error ("GCC must be configured with %<--enable-newlib-nano-formatted-io%> "
           "to use %<-mtiny-printf%>");
#endif
}

#undef  TARGET_SCALAR_MODE_SUPPORTED_P
#define TARGET_SCALAR_MODE_SUPPORTED_P msp430_scalar_mode_supported_p

static bool
msp430_scalar_mode_supported_p (scalar_mode m)
{
  if (m == PSImode && msp430x)
    return true;
#if 0
  if (m == TImode)
    return true;
#endif
  return default_scalar_mode_supported_p (m);
}

\f

/* Storage Layout */

#undef  TARGET_MS_BITFIELD_LAYOUT_P
#define TARGET_MS_BITFIELD_LAYOUT_P msp430_ms_bitfield_layout_p

bool
msp430_ms_bitfield_layout_p (const_tree record_type ATTRIBUTE_UNUSED)
{
  return false;
}

\f

/* Register Usage */

#undef TARGET_HARD_REGNO_NREGS
#define TARGET_HARD_REGNO_NREGS msp430_hard_regno_nregs

static unsigned int
msp430_hard_regno_nregs (unsigned int, machine_mode mode)
{
  if (mode == PSImode && msp430x)
    return 1;
  if (mode == CPSImode && msp430x)
    return 2;
  return ((GET_MODE_SIZE (mode) + UNITS_PER_WORD - 1)
          / UNITS_PER_WORD);
}

/* subreg_get_info correctly handles PSImode registers, so defining
   HARD_REGNO_NREGS_HAS_PADDING and HARD_REGNO_NREGS_WITH_PADDING
   has no effect.  */

#undef TARGET_HARD_REGNO_MODE_OK
#define TARGET_HARD_REGNO_MODE_OK msp430_hard_regno_mode_ok

static bool
msp430_hard_regno_mode_ok (unsigned int regno, machine_mode mode)
{
  return regno <= (ARG_POINTER_REGNUM
                   - (unsigned int) msp430_hard_regno_nregs (regno, mode));
}

#undef TARGET_MODES_TIEABLE_P
#define TARGET_MODES_TIEABLE_P msp430_modes_tieable_p

static bool
msp430_modes_tieable_p (machine_mode mode1, machine_mode mode2)
{
  if ((mode1 == PSImode || mode2 == SImode)
      || (mode1 == SImode || mode2 == PSImode))
    return false;

  return ((GET_MODE_CLASS (mode1) == MODE_FLOAT
           || GET_MODE_CLASS (mode1) == MODE_COMPLEX_FLOAT)
          == (GET_MODE_CLASS (mode2) == MODE_FLOAT
              || GET_MODE_CLASS (mode2) == MODE_COMPLEX_FLOAT));
}

#undef  TARGET_FRAME_POINTER_REQUIRED
#define TARGET_FRAME_POINTER_REQUIRED msp430_frame_pointer_required

static bool
msp430_frame_pointer_required (void)
{
  return false;
}

#undef  TARGET_CAN_ELIMINATE
#define TARGET_CAN_ELIMINATE            msp430_can_eliminate

static bool
msp430_can_eliminate (const int from_reg ATTRIBUTE_UNUSED,
                      const int to_reg ATTRIBUTE_UNUSED)
{
  return true;
}

/* Implements INITIAL_ELIMINATION_OFFSET.  */
int
msp430_initial_elimination_offset (int from, int to)
{
  int rv = 0; /* As if arg to arg.  */

  msp430_compute_frame_info ();

  switch (to)
    {
    case STACK_POINTER_REGNUM:
      rv += cfun->machine->framesize_outgoing;
      rv += cfun->machine->framesize_locals;
      /* Fall through.  */
    case FRAME_POINTER_REGNUM:
      rv += cfun->machine->framesize_regs;
      /* Allow for the saved return address.  */
      rv += (TARGET_LARGE ? 4 : 2);
      /* NB/ No need to allow for crtl->args.pretend_args_size.
         GCC does that for us.  */
      break;
    default:
      gcc_unreachable ();
    }

  switch (from)
    {
    case FRAME_POINTER_REGNUM:
      /* Allow for the fall through above.  */
      rv -= (TARGET_LARGE ? 4 : 2);
      rv -= cfun->machine->framesize_regs;
    case ARG_POINTER_REGNUM:
      break;
    default:
      gcc_unreachable ();
    }

  return rv;
}
\f
/* Named Address Space support */


/* Return the appropriate mode for a named address pointer.  */
#undef  TARGET_ADDR_SPACE_POINTER_MODE
#define TARGET_ADDR_SPACE_POINTER_MODE msp430_addr_space_pointer_mode
#undef  TARGET_ADDR_SPACE_ADDRESS_MODE
#define TARGET_ADDR_SPACE_ADDRESS_MODE msp430_addr_space_pointer_mode

static scalar_int_mode
msp430_addr_space_pointer_mode (addr_space_t addrspace)
{
  switch (addrspace)
    {
    default:
    case ADDR_SPACE_GENERIC:
      return Pmode;
    case ADDR_SPACE_NEAR:
      return HImode;
    case ADDR_SPACE_FAR:
      return PSImode;
    }
}

/* Function pointers are stored in unwind_word sized
   variables, so make sure that unwind_word is big enough.  */
#undef  TARGET_UNWIND_WORD_MODE
#define TARGET_UNWIND_WORD_MODE msp430_unwind_word_mode

static scalar_int_mode
msp430_unwind_word_mode (void)
{
  /* This needs to match msp430_init_dwarf_reg_sizes_extra (below).  */
  return msp430x ? PSImode : HImode;
}

/* Determine if one named address space is a subset of another.  */
#undef  TARGET_ADDR_SPACE_SUBSET_P
#define TARGET_ADDR_SPACE_SUBSET_P msp430_addr_space_subset_p
static bool
msp430_addr_space_subset_p (addr_space_t subset, addr_space_t superset)
{
  if (subset == superset)
    return true;
  else
    return (subset != ADDR_SPACE_FAR && superset == ADDR_SPACE_FAR);
}

#undef  TARGET_ADDR_SPACE_CONVERT
#define TARGET_ADDR_SPACE_CONVERT msp430_addr_space_convert
/* Convert from one address space to another.  */
static rtx
msp430_addr_space_convert (rtx op, tree from_type, tree to_type)
{
  addr_space_t from_as = TYPE_ADDR_SPACE (TREE_TYPE (from_type));
  addr_space_t to_as = TYPE_ADDR_SPACE (TREE_TYPE (to_type));
  rtx result;

  if (to_as != ADDR_SPACE_FAR && from_as == ADDR_SPACE_FAR)
    {
      /* This is unpredictable, as we're truncating off usable address
         bits.  */

      if (CONSTANT_P (op))
        return gen_rtx_CONST (HImode, op);

      result = gen_reg_rtx (HImode);
      emit_insn (gen_truncpsihi2 (result, op));
      return result;
    }
  else if (to_as == ADDR_SPACE_FAR && from_as != ADDR_SPACE_FAR)
    {
      /* This always works.  */

      if (CONSTANT_P (op))
        return gen_rtx_CONST (PSImode, op);

      result = gen_reg_rtx (PSImode);
      emit_insn (gen_zero_extendhipsi2 (result, op));
      return result;
    }
  else
    gcc_unreachable ();
}
\f
/* Stack Layout and Calling Conventions.  */

/* For each function, we list the gcc version and the TI version on
   each line, where we're converting the function names.  */
static char const * const special_convention_function_names[] =
{
  "__muldi3", "__mspabi_mpyll",
  "__udivdi3", "__mspabi_divull",
  "__umoddi3", "__mspabi_remull",
  "__divdi3", "__mspabi_divlli",
  "__moddi3", "__mspabi_remlli",
  "__mspabi_srall",
  "__mspabi_srlll",
  "__mspabi_sllll",
  "__adddf3", "__mspabi_addd",
  "__subdf3", "__mspabi_subd",
  "__muldf3", "__mspabi_mpyd",
  "__divdf3", "__mspabi_divd",
  "__mspabi_cmpd",
  NULL
};

/* TRUE if the function passed is a "speical" function.  Special
   functions pass two DImode parameters in registers.  */
static bool
msp430_special_register_convention_p (const char *name)
{
  int i;

  for (i = 0; special_convention_function_names[i]; i++)
    if (!strcmp (name, special_convention_function_names[i]))
      return true;

  return false;
}

#undef  TARGET_FUNCTION_VALUE_REGNO_P
#define TARGET_FUNCTION_VALUE_REGNO_P msp430_function_value_regno_p

bool
msp430_function_value_regno_p (unsigned int regno)
{
  return regno == 12;
}


#undef  TARGET_FUNCTION_VALUE
#define TARGET_FUNCTION_VALUE msp430_function_value

rtx
msp430_function_value (const_tree ret_type,
                       const_tree fn_decl_or_type ATTRIBUTE_UNUSED,
                       bool outgoing ATTRIBUTE_UNUSED)
{
  return gen_rtx_REG (TYPE_MODE (ret_type), 12);
}

#undef  TARGET_LIBCALL_VALUE
#define TARGET_LIBCALL_VALUE msp430_libcall_value

rtx
msp430_libcall_value (machine_mode mode, const_rtx fun ATTRIBUTE_UNUSED)
{
  return gen_rtx_REG (mode, 12);
}

/* Implements INIT_CUMULATIVE_ARGS.  */
void
msp430_init_cumulative_args (CUMULATIVE_ARGS *ca,
                             tree fntype ATTRIBUTE_UNUSED,
                             rtx libname ATTRIBUTE_UNUSED,
                             tree fndecl ATTRIBUTE_UNUSED,
                             int n_named_args ATTRIBUTE_UNUSED)
{
  const char *fname;
  memset (ca, 0, sizeof(*ca));

  ca->can_split = 1;

  if (fndecl)
    fname = IDENTIFIER_POINTER (DECL_NAME (fndecl));
  else if (libname)
    fname = XSTR (libname, 0);
  else
    fname = NULL;

  if (fname && msp430_special_register_convention_p (fname))
    ca->special_p = 1;
}

/* Helper function for argument passing; this function is the common
   code that determines where an argument will be passed.  */
static void
msp430_evaluate_arg (cumulative_args_t cap,
                     machine_mode mode,
                     const_tree type ATTRIBUTE_UNUSED,
                     bool named)
{
  CUMULATIVE_ARGS *ca = get_cumulative_args (cap);
  int nregs = GET_MODE_SIZE (mode);
  int i;

  ca->reg_count = 0;
  ca->mem_count = 0;

  if (!named)
    return;

  if (mode == PSImode)
    nregs = 1;
  else
    nregs = (nregs + 1) / 2;

  if (ca->special_p)
    {
      /* Function is passed two DImode operands, in R8:R11 and
         R12:15.  */
      ca->start_reg = 8;
      ca->reg_count = 4;
      return;
    }

  switch (nregs)
    {
    case 1:
      for (i = 0; i < 4; i++)
        if (!ca->reg_used[i])
          {
            ca->reg_count = 1;
            ca->start_reg = CA_FIRST_REG + i;
            return;
          }
      break;
    case 2:
      for (i = 0; i < 3; i++)
        if (!ca->reg_used[i] && !ca->reg_used[i + 1])
          {
            ca->reg_count = 2;
            ca->start_reg = CA_FIRST_REG + i;
            return;
          }
      if (!ca->reg_used[3] && ca->can_split)
        {
          ca->reg_count = 1;
          ca->mem_count = 2;
          ca->start_reg = CA_FIRST_REG + 3;
          return;
        }
      break;
    case 3:
    case 4:
      ca->can_split = 0;
      if (!ca->reg_used[0]
          && !ca->reg_used[1]
          && !ca->reg_used[2]
          && !ca->reg_used[3])
        {
          ca->reg_count = 4;
          ca->start_reg = CA_FIRST_REG;
          return;
        }
      break;
    }
}

#undef  TARGET_PROMOTE_PROTOTYPES
#define TARGET_PROMOTE_PROTOTYPES msp430_promote_prototypes

bool
msp430_promote_prototypes (const_tree fntype ATTRIBUTE_UNUSED)
{
  return false;
}

#undef  TARGET_FUNCTION_ARG
#define TARGET_FUNCTION_ARG msp430_function_arg

rtx
msp430_function_arg (cumulative_args_t cap,
                     const function_arg_info &arg)
{
  CUMULATIVE_ARGS *ca = get_cumulative_args (cap);

  msp430_evaluate_arg (cap, arg.mode, arg.type, arg.named);

  if (ca->reg_count)
    return gen_rtx_REG (arg.mode, ca->start_reg);

  return 0;
}

#undef  TARGET_ARG_PARTIAL_BYTES
#define TARGET_ARG_PARTIAL_BYTES msp430_arg_partial_bytes

int
msp430_arg_partial_bytes (cumulative_args_t cap, const function_arg_info &arg)
{
  CUMULATIVE_ARGS *ca = get_cumulative_args (cap);

  msp430_evaluate_arg (cap, arg.mode, arg.type, arg.named);

  if (ca->reg_count && ca->mem_count)
    return ca->reg_count * UNITS_PER_WORD;

  return 0;
}

#undef  TARGET_PASS_BY_REFERENCE
#define TARGET_PASS_BY_REFERENCE msp430_pass_by_reference

static bool
msp430_pass_by_reference (cumulative_args_t, const function_arg_info &arg)
{
  return (arg.mode == BLKmode
          || (arg.type && TREE_CODE (arg.type) == RECORD_TYPE)
          || (arg.type && TREE_CODE (arg.type) == UNION_TYPE));
}

#undef  TARGET_CALLEE_COPIES
#define TARGET_CALLEE_COPIES hook_bool_CUMULATIVE_ARGS_arg_info_true

#undef  TARGET_FUNCTION_ARG_ADVANCE
#define TARGET_FUNCTION_ARG_ADVANCE msp430_function_arg_advance

void
msp430_function_arg_advance (cumulative_args_t cap,
                             const function_arg_info &arg)
{
  CUMULATIVE_ARGS *ca = get_cumulative_args (cap);
  int i;

  msp430_evaluate_arg (cap, arg.mode, arg.type, arg.named);

  if (ca->start_reg >= CA_FIRST_REG)
    for (i = 0; i < ca->reg_count; i ++)
      ca->reg_used[i + ca->start_reg - CA_FIRST_REG] = 1;

  ca->special_p = 0;
}

#undef  TARGET_FUNCTION_ARG_BOUNDARY
#define TARGET_FUNCTION_ARG_BOUNDARY msp430_function_arg_boundary

static unsigned int
msp430_function_arg_boundary (machine_mode mode, const_tree type)
{
  if (mode == BLKmode
      && int_size_in_bytes (type) > 1)
    return 16;
  if (GET_MODE_BITSIZE (mode) > 8)
    return 16;
  return 8;
}

#undef  TARGET_RETURN_IN_MEMORY
#define TARGET_RETURN_IN_MEMORY msp430_return_in_memory

static bool
msp430_return_in_memory (const_tree ret_type,
                         const_tree fntype ATTRIBUTE_UNUSED)
{
  machine_mode mode = TYPE_MODE (ret_type);

  if (mode == BLKmode
      || (fntype && TREE_CODE (TREE_TYPE (fntype)) == RECORD_TYPE)
      || (fntype && TREE_CODE (TREE_TYPE (fntype)) == UNION_TYPE))
    return true;

  if (GET_MODE_SIZE (mode) > 8)
    return true;

  return false;
}

#undef  TARGET_GET_RAW_ARG_MODE
#define TARGET_GET_RAW_ARG_MODE msp430_get_raw_arg_mode

static fixed_size_mode
msp430_get_raw_arg_mode (int regno)
{
  return as_a <fixed_size_mode> (regno == ARG_POINTER_REGNUM
                                 ? VOIDmode : Pmode);
}

#undef  TARGET_GET_RAW_RESULT_MODE
#define TARGET_GET_RAW_RESULT_MODE msp430_get_raw_result_mode

static fixed_size_mode
msp430_get_raw_result_mode (int regno ATTRIBUTE_UNUSED)
{
  return Pmode;
}

#undef  TARGET_GIMPLIFY_VA_ARG_EXPR
#define TARGET_GIMPLIFY_VA_ARG_EXPR msp430_gimplify_va_arg_expr

#include "gimplify.h"

static tree
msp430_gimplify_va_arg_expr (tree valist, tree type, gimple_seq *pre_p,
                             gimple_seq *post_p)
{
  tree addr, t, type_size, rounded_size, valist_tmp;
  unsigned HOST_WIDE_INT align, boundary;
  bool indirect;

  indirect = pass_va_arg_by_reference (type);
  if (indirect)
    type = build_pointer_type (type);

  align = PARM_BOUNDARY / BITS_PER_UNIT;
  boundary = targetm.calls.function_arg_boundary (TYPE_MODE (type), type);

  /* When we align parameter on stack for caller, if the parameter
     alignment is beyond MAX_SUPPORTED_STACK_ALIGNMENT, it will be
     aligned at MAX_SUPPORTED_STACK_ALIGNMENT.  We will match callee
     here with caller.  */
  if (boundary > MAX_SUPPORTED_STACK_ALIGNMENT)
    boundary = MAX_SUPPORTED_STACK_ALIGNMENT;

  boundary /= BITS_PER_UNIT;

  /* Hoist the valist value into a temporary for the moment.  */
  valist_tmp = get_initialized_tmp_var (valist, pre_p, NULL);

  /* va_list pointer is aligned to PARM_BOUNDARY.  If argument actually
     requires greater alignment, we must perform dynamic alignment.  */
  if (boundary > align
      && !integer_zerop (TYPE_SIZE (type)))
    {
      /* FIXME: This is where this function diverts from targhooks.cc:
         std_gimplify_va_arg_expr().  It works, but I do not know why...  */
      if (! POINTER_TYPE_P (type))
        {
          t = build2 (MODIFY_EXPR, TREE_TYPE (valist), valist_tmp,
                      fold_build_pointer_plus_hwi (valist_tmp, boundary - 1));
          gimplify_and_add (t, pre_p);

          t = build2 (MODIFY_EXPR, TREE_TYPE (valist), valist_tmp,
                      fold_build2 (BIT_AND_EXPR, TREE_TYPE (valist),
                                   valist_tmp,
                                   build_int_cst (TREE_TYPE (valist),
                                                  -boundary)));
          gimplify_and_add (t, pre_p);
        }
    }
  else
    boundary = align;

  /* If the actual alignment is less than the alignment of the type,
     adjust the type accordingly so that we don't assume strict alignment
     when dereferencing the pointer.  */
  boundary *= BITS_PER_UNIT;
  if (boundary < TYPE_ALIGN (type))
    {
      type = build_variant_type_copy (type);
      SET_TYPE_ALIGN (type, boundary);
    }

  /* Compute the rounded size of the type.  */
  type_size = size_in_bytes (type);
  rounded_size = round_up (type_size, align);

  /* Reduce rounded_size so it's sharable with the postqueue.  */
  gimplify_expr (&rounded_size, pre_p, post_p, is_gimple_val, fb_rvalue);

  /* Get AP.  */
  addr = valist_tmp;

  /* Compute new value for AP.  */
  t = fold_build_pointer_plus (valist_tmp, rounded_size);
  t = build2 (MODIFY_EXPR, TREE_TYPE (valist), valist, t);
  gimplify_and_add (t, pre_p);

  addr = fold_convert (build_pointer_type (type), addr);

  if (indirect)
    addr = build_va_arg_indirect_ref (addr);

  addr = build_va_arg_indirect_ref (addr);

  return addr;
}
\f
#undef TARGET_LRA_P
#define TARGET_LRA_P hook_bool_void_false

/* Addressing Modes */

#undef  TARGET_LEGITIMATE_ADDRESS_P
#define TARGET_LEGITIMATE_ADDRESS_P msp430_legitimate_address_p

static bool
reg_ok_for_addr (rtx r, bool strict)
{
  int rn = REGNO (r);

  if (strict && rn >= FIRST_PSEUDO_REGISTER)
    rn = reg_renumber[rn];
  if (strict && 0 <= rn && rn < FIRST_PSEUDO_REGISTER)
    return true;
  if (!strict)
    return true;
  return false;
}

bool
msp430_legitimate_address_p (machine_mode mode ATTRIBUTE_UNUSED,
                             rtx x ATTRIBUTE_UNUSED,
                             bool strict ATTRIBUTE_UNUSED)
{
  switch (GET_CODE (x))
    {
    case MEM:
      return false;

    case PLUS:
    case POST_INC:
      if (REG_P (XEXP (x, 0)))
        {
          if (GET_MODE (x) != GET_MODE (XEXP (x, 0)))
            return false;
          if (!reg_ok_for_addr (XEXP (x, 0), strict))
            return false;
          if (GET_CODE (x) == POST_INC)
            /* At this point, if the original rtx was a post_inc, we don't have
               anything further to check.  */
            return true;
          switch (GET_CODE (XEXP (x, 1)))
            {
            case CONST:
            case SYMBOL_REF:
            case CONST_INT:
              return true;
            default:
              return false;
            }
        }
      return false;

    case REG:
      if (!reg_ok_for_addr (x, strict))
        return false;
      /* FALLTHRU */
    case CONST:
    case SYMBOL_REF:
    case CONST_INT:
      return true;

    default:
      return false;
    }
}

#undef  TARGET_ADDR_SPACE_LEGITIMATE_ADDRESS_P
#define TARGET_ADDR_SPACE_LEGITIMATE_ADDRESS_P \
  msp430_addr_space_legitimate_address_p

bool
msp430_addr_space_legitimate_address_p (machine_mode mode,
                                        rtx x,
                                        bool strict,
                                        addr_space_t as ATTRIBUTE_UNUSED)
{
  return msp430_legitimate_address_p (mode, x, strict);
}

#undef  TARGET_ASM_INTEGER
#define TARGET_ASM_INTEGER msp430_asm_integer
static bool
msp430_asm_integer (rtx x, unsigned int size, int aligned_p)
{
  int c = GET_CODE (x);

  if (size == 3 && GET_MODE (x) == PSImode)
    size = 4;

  switch (size)
    {
    case 4:
      if (c == SYMBOL_REF || c == CONST || c == LABEL_REF || c == CONST_INT
          || c == PLUS || c == MINUS)
        {
          fprintf (asm_out_file, "\t.long\t");
          output_addr_const (asm_out_file, x);
          fputc ('\n', asm_out_file);
          return true;
        }
      break;
    }
  return default_assemble_integer (x, size, aligned_p);
}

#undef  TARGET_ASM_OUTPUT_ADDR_CONST_EXTRA
#define TARGET_ASM_OUTPUT_ADDR_CONST_EXTRA msp430_asm_output_addr_const_extra
static bool
msp430_asm_output_addr_const_extra (FILE *file ATTRIBUTE_UNUSED, rtx x)
{
  debug_rtx (x);
  return false;
}

#undef  TARGET_LEGITIMATE_CONSTANT_P
#define TARGET_LEGITIMATE_CONSTANT_P msp430_legitimate_constant

static bool
msp430_legitimate_constant (machine_mode mode, rtx x)
{
  return ! CONST_INT_P (x)
    || mode != PSImode
    /* GCC does not know the width of the PSImode, so make
       sure that it does not try to use a constant value that
       is out of range.  */
    || (INTVAL (x) < (1 << 20)
        && INTVAL (x) >= (HOST_WIDE_INT)(HOST_WIDE_INT_M1U << 20));
}

\f
/* Describing Relative Costs of Operations
   To model the cost of an instruction, use the number of cycles when
   optimizing for speed, and the number of words when optimizing for size.
   The cheapest instruction will execute in one cycle and cost one word.
   The cycle and size costs correspond to 430 ISA instructions, not 430X
   instructions or 430X "address" instructions.  The relative costs of 430X
   instructions is accurately modeled with the 430 costs.  The relative costs
   of some "address" instructions can differ, but these are not yet handled.
   Adding support for this could improve performance/code size.  */

struct single_op_cost
{
  const int reg;
  /* Indirect register (@Rn) or indirect autoincrement (@Rn+).  */
  const int ind;
  const int mem;
};

static const struct single_op_cost cycle_cost_single_op =
{
  1, 3, 4
};

static const struct single_op_cost size_cost_single_op =
{
  1, 1, 2
};

/* When the destination of an insn is memory, the cost is always the same
   regardless of whether that memory is accessed using indirect register,
   indexed or absolute addressing.
   When the source operand is memory, indirect register and post-increment have
   the same cost, which is lower than indexed and absolute, which also have
   the same cost.  */
struct double_op_cost
{
  /* Source operand is a register.  */
  const int r2r;
  const int r2pc;
  const int r2m;

  /* Source operand is memory, using indirect register (@Rn) or indirect
     autoincrement (@Rn+) addressing modes.  */
  const int ind2r;
  const int ind2pc;
  const int ind2m;

  /* Source operand is an immediate.  */
  const int imm2r;
  const int imm2pc;
  const int imm2m;

  /* Source operand is memory, using indexed (x(Rn)) or absolute (&ADDR)
     addressing modes.  */
  const int mem2r;
  const int mem2pc;
  const int mem2m;
};

/* These structures describe the cost of MOV, BIT and CMP instructions, in terms
   of clock cycles or words.  */
static const struct double_op_cost cycle_cost_double_op_mov =
{
  1, 3, 3,
  2, 4, 4,
  2, 3, 4,
  3, 5, 5
};

/* Cycle count when memory is the destination operand is one larger than above
   for instructions that aren't MOV, BIT or CMP.  */
static const struct double_op_cost cycle_cost_double_op =
{
  1, 3, 4,
  2, 4, 5,
  2, 3, 5,
  3, 5, 6
};

static const struct double_op_cost size_cost_double_op =
{
  1, 1, 2,
  1, 1, 2,
  2, 2, 3,
  2, 2, 3
};

struct msp430_multlib_costs
{
  const int mulhi;
  const int mulsi;
  const int muldi;
};

/* There is no precise size cost when using libcalls, instead it is disparaged
   relative to other instructions.
   The cycle costs are from the CALL to the RET, inclusive.
   FIXME muldi cost is not accurate.  */
static const struct msp430_multlib_costs cycle_cost_multlib_32bit =
{
  27, 33, 66
};

/* 32bit multiply takes a few more instructions on 16bit hwmult.  */
static const struct msp430_multlib_costs cycle_cost_multlib_16bit =
{
  27, 42, 66
};

/* TARGET_REGISTER_MOVE_COST
   There is only one class of general-purpose, non-fixed registers, and the
   relative cost of moving data between them is always the same.
   Therefore, the default of 2 is optimal.  */

#undef TARGET_MEMORY_MOVE_COST
#define TARGET_MEMORY_MOVE_COST msp430_memory_move_cost

/* Return the cost of moving data between registers and memory.
   The returned cost must be relative to the default TARGET_REGISTER_MOVE_COST
   of 2.
   IN is false if the value is to be written to memory.  */
static int
msp430_memory_move_cost (machine_mode mode ATTRIBUTE_UNUSED,
                         reg_class_t rclass ATTRIBUTE_UNUSED,
                         bool in)
{
  int cost;
  const struct double_op_cost *cost_p;
  /* Optimize with a code size focus by default, unless -O2 or above is
     specified.  */
  bool speed = (!optimize_size && optimize >= 2);

  cost_p = (speed ? &cycle_cost_double_op_mov : &size_cost_double_op);

  if (in)
    /* Reading from memory using indirect addressing is assumed to be the more
       common case.  */
    cost = cost_p->ind2r;
  else
    cost = cost_p->r2m;

  /* All register to register moves cost 1 cycle or 1 word, so multiply by 2
     to get the costs relative to TARGET_REGISTER_MOVE_COST of 2.  */
  return 2 * cost;
}

/* For X, which must be a MEM RTX, return TRUE if it is an indirect memory
   reference, @Rn or @Rn+.  */
static bool
msp430_is_mem_indirect (rtx x)
{
  gcc_assert (GET_CODE (x) == MEM);
  rtx op0 = XEXP (x, 0);
  return (GET_CODE (op0) == REG || GET_CODE (op0) == POST_INC);
}

/* Costs of MSP430 instructions are generally based on the addressing mode
   combination of the source and destination operands.
   Given source operand SRC (which may be NULL to indicate a single-operand
   instruction) and destination operand DST return the cost of this
   expression.  */
static int
msp430_costs (rtx src, rtx dst, bool speed, rtx outer_rtx)
{
  enum rtx_code src_code = GET_CODE (src);
  enum rtx_code dst_code = GET_CODE (dst);
  enum rtx_code outer_code = GET_CODE (outer_rtx);
  machine_mode outer_mode = GET_MODE (outer_rtx);
  const struct double_op_cost *cost_p;
  cost_p = (speed ? &cycle_cost_double_op : &size_cost_double_op);

  if (outer_code == TRUNCATE
      && (outer_mode == QImode
          || outer_mode == HImode
          || outer_mode == PSImode))
    /* Truncation to these modes is normally free as a side effect of the
       instructions themselves.  */
    return 0;

  if (dst_code == SYMBOL_REF
      || dst_code == LABEL_REF
      || dst_code == CONST_INT)
    /* Catch RTX like (minus (const_int 0) (reg)) but don't add any cost.  */
    return 0;

  switch (src_code)
    {
    case REG:
      return (dst_code == REG ? cost_p->r2r
              : (dst_code == PC ? cost_p->r2pc : cost_p->r2m));

    case CONST_INT:
    case SYMBOL_REF:
    case LABEL_REF:
    case CONST:
      return (dst_code == REG ? cost_p->imm2r
              : (dst_code == PC ? cost_p->imm2pc : cost_p->imm2m));


    case MEM:
      if (msp430_is_mem_indirect (src))
        return (dst_code == REG ? cost_p->ind2r : (dst_code == PC
                                                   ? cost_p->ind2pc
                                                   : cost_p->ind2m));
      else
        return (dst_code == REG ? cost_p->mem2r : (dst_code == PC
                                                   ? cost_p->mem2pc
                                                   : cost_p->mem2m));
    default:
      return cost_p->mem2m;
    }
}

/* Given source operand SRC and destination operand DST from the shift or
   rotate RTX OUTER_RTX, return the cost of performing that shift, assuming
   optimization for speed when SPEED is true.  */
static int
msp430_shift_costs (rtx src, rtx dst, bool speed, rtx outer_rtx)
{
  int amt;
  enum rtx_code src_code = GET_CODE (src);
  enum rtx_code dst_code = GET_CODE (dst);
  const struct single_op_cost *cost_p;

  cost_p = (speed ? &cycle_cost_single_op : &size_cost_single_op);

  if (src_code != CONST_INT)
    /* The size or speed cost when the shift amount is unknown cannot be
       accurately calculated, so just disparage it slightly.  */
    return 2 * msp430_costs (src, dst, speed, outer_rtx);

  if (use_helper_for_const_shift (GET_MODE (outer_rtx), amt = INTVAL (src)))
    {
      /* GCC sometimes tries to perform shifts in some very inventive ways,
         resulting in much larger code size usage than necessary, if
         they are disparaged too much here.  So in general, if
         use_helper_for_const_shift thinks a helper should be used, obey
         that and don't disparage the shift any more than a regular
         instruction, even though the shift may actually cost more.
         This ensures that the RTL generated at the initial expand pass has the
         expected shift instructions, which can be mapped to the helper
         functions.  */
      return msp430_costs (src, dst, speed, outer_rtx);
    }

  if (!msp430x)
    {
      /* Each shift by one place will be emitted individually.  */
      switch (dst_code)
        {
        case REG:
        case CONST_INT:
          return amt * cost_p->reg;
        case MEM:
          if (msp430_is_mem_indirect (dst))
            return amt * cost_p->ind;
          else
            return amt * cost_p->mem;
        default:
          return amt * cost_p->mem;
        }
    }

  /* RRAM, RRCM, RRUM, RLAM are used for shift counts <= 4, otherwise, the 'X'
     versions are used.
     Instructions which shift a MEM operand will never actually be output.  It
     will always be copied into a register to allow for efficient shifting.  So
     the cost just takes into account the cost of an additional copy in that
     case.  */
  return (amt <= 4 ? (speed ? amt : 1) : (speed ? amt + 1 : 2)
          + (dst_code == REG ? 0
             : msp430_costs (dst, gen_rtx_REG (HImode, 10), speed, outer_rtx)));
}

/* Given source operand SRC and destination operand DST from the MULT/DIV/MOD
   RTX OUTER_RTX, return the cost of performing that operation, assuming
   optimization for speed when SPEED is true.  */
static int
msp430_muldiv_costs (rtx src, rtx dst, bool speed, rtx outer_rtx,
                     machine_mode outer_mode)
{
  enum rtx_code outer_code = GET_CODE (outer_rtx);
  const struct msp430_multlib_costs *cost_p;
  cost_p = (msp430_use_16bit_hwmult ()
            ? &cycle_cost_multlib_32bit
            : &cycle_cost_multlib_16bit);

  int factor = 1;
  /* Only used in some calculations.  */
  int mode_factor = 1;
  if (outer_mode == SImode)
    mode_factor = 2;
  else if (outer_mode == PSImode)
    /* PSImode multiplication is performed using SImode operands, so has extra
       cost to factor in the conversions necessary before/after the
       operation.  */
    mode_factor = 3;
  else if (outer_mode == DImode)
    mode_factor = 4;

  if (!speed)
    {
      /* The codesize cost of using a helper function to perform the
         multiplication or division cannot be accurately calculated, since the
         cost depends on how many times the operation is performed in the
         entire program.  */
      if (outer_code != MULT)
        /* Division is always expensive.  */
        factor = 7;
      else if (((msp430_use_16bit_hwmult () && outer_mode != DImode)
                || msp430_use_32bit_hwmult ()
                || msp430_use_f5_series_hwmult ()))
        /* When the hardware multiplier is available, only disparage
           slightly.  */
        factor = 2;
      else
        factor = 5;
      return factor * mode_factor * msp430_costs (src, dst, speed, outer_rtx);
    }

  /* When there is hardware multiply support, there is a relatively low, fixed
     cycle cost to performing any multiplication, but when there is no hardware
     multiply support it is very costly.  That precise cycle cost has not been
     calculated here.
     Division is extra slow since it always uses a software library.
     The 16-bit hardware multiply library cannot be used to produce 64-bit
     results.  */
  if (outer_code != MULT || !msp430_has_hwmult ()
      || (outer_mode == DImode && msp430_use_16bit_hwmult ()))
    {
      factor = (outer_code == MULT ? 50 : 70);
      return factor * mode_factor * msp430_costs (src, dst, speed, outer_rtx);
    }

  switch (outer_mode)
    {
    case E_QImode:
    case E_HImode:
      /* Include the cost of copying the operands into and out of the hardware
         multiply routine.  */
      return cost_p->mulhi + (3 * msp430_costs (src, dst, speed, outer_rtx));

    case E_PSImode:
      /* Extra factor for the conversions necessary to do PSI->SI before the
         operation.  */
      factor = 2;
      /* fallthru.  */
    case E_SImode:
      return factor * (cost_p->mulsi
                       + (6 * msp430_costs (src, dst, speed, outer_rtx)));

    case E_DImode:
    default:
      return cost_p->muldi + (12 * msp430_costs (src, dst, speed, outer_rtx));
    }
}

/* Recurse within X to find the actual destination operand of the expression.
   For example:
   (plus (ashift (minus (ashift (reg)
   (const_int) ......
   should return the reg RTX.  */
static rtx
msp430_get_inner_dest_code (rtx x)
{
  enum rtx_code code = GET_CODE (x);
  rtx op0 = XEXP (x, 0);
  switch (code)
    {
    case REG:
    case SYMBOL_REF:
    case CONST_INT:
    case CONST:
    case LABEL_REF:
      return x;

    case MEM:
      /* Return the MEM expr not the inner REG for these cases.  */
      switch (GET_CODE (op0))
        {
        case REG:
        case SYMBOL_REF:
        case LABEL_REF:
        case CONST:
        case POST_INC:
          return x;

        case PLUS:
          /* return MEM (PLUS (REG) (CONST)) */
          if (GET_CODE (XEXP (op0, 0)) == REG)
            {
              if (GET_CODE (XEXP (op0, 1)) == CONST_INT
                  || GET_CODE (XEXP (op0, 1)) == CONST
                  || GET_CODE (XEXP (op0, 1)) == LABEL_REF
                  || GET_CODE (XEXP (op0, 1)) == SYMBOL_REF)
                return x;
              else
                return msp430_get_inner_dest_code (op0);
            }
          return msp430_get_inner_dest_code (op0);

        default:
          if (GET_RTX_FORMAT (code)[0] != 'e')
            return x;
          return msp430_get_inner_dest_code (op0);
        }
      break;

    default:
      if (op0 == NULL_RTX)
        gcc_unreachable ();
      else
        {
          if (GET_RTX_FORMAT (code)[0] != 'e'
              && code != ENTRY_VALUE)
            return x;
          return msp430_get_inner_dest_code (op0);
        }
    }
}

/* Calculate the cost of an MSP430 single-operand instruction, for operand DST
   within the RTX OUTER_RTX, optimizing for speed if SPEED is true.  */
static int
msp430_single_op_cost (rtx dst, bool speed, rtx /* outer_rtx */)
{
  enum rtx_code dst_code = GET_CODE (dst);
  const struct single_op_cost *cost_p;
  const struct double_op_cost *double_op_cost_p;

  cost_p = (speed ? &cycle_cost_single_op : &size_cost_single_op);
  double_op_cost_p = (speed ? &cycle_cost_double_op : &size_cost_double_op);

  switch (dst_code)
    {
    case REG:
      return cost_p->reg;
    case MEM:
      if (msp430_is_mem_indirect (dst))
        return cost_p->ind;
      else
        return cost_p->mem;

    case CONST_INT:
    case CONST_FIXED:
    case CONST_DOUBLE:
    case SYMBOL_REF:
    case CONST:
      /* A constant value would need to be copied into a register first.  */
      return double_op_cost_p->imm2r + cost_p->reg;

    default:
      return cost_p->mem;
    }
}

#undef  TARGET_RTX_COSTS
#define TARGET_RTX_COSTS msp430_rtx_costs

/* This target hook describes the relative costs of RTL expressions.
   The function recurses to just before the lowest level of the expression,
   when both of the operands of the expression can be examined at the same time.
   This is because the cost of the expression depends on the specific
   addressing mode combination of the operands.
   The hook returns true when all subexpressions of X have been processed, and
   false when rtx_cost should recurse.  */
static bool
msp430_rtx_costs (rtx x,
                  machine_mode mode,
                  int      outer_code ATTRIBUTE_UNUSED,
                  int      opno ATTRIBUTE_UNUSED,
                  int *    total,
                  bool     speed)
{
  enum rtx_code code = GET_CODE (x);
  rtx dst, src;
  rtx dst_inner, src_inner;

  *total = 0;
  dst = XEXP (x, 0);
  if (GET_RTX_LENGTH (code) == 1)
    /* Some RTX that are single-op in GCC are double-op when translated to
       MSP430 instructions e.g NOT, NEG, ZERO_EXTEND.  */
    src = dst;
  else
    src = XEXP (x, 1);


  switch (code)
    {
    case SET:
      /* Ignoring SET improves codesize.  */
      if (!speed)
        return true;
      /* fallthru.  */
    case PLUS:
      if (outer_code == MEM)
        /* Do not add any cost for the plus itself, but recurse in case there
           are more complicated RTX inside.  */
        return false;
      /* fallthru.  */
    case MINUS:
    case AND:
    case IOR:
    case XOR:
    case NOT:
    case ZERO_EXTEND:
    case TRUNCATE:
    case NEG:
    case ZERO_EXTRACT:
    case SIGN_EXTRACT:
    case IF_THEN_ELSE:
      dst_inner = msp430_get_inner_dest_code (dst);
      src_inner = msp430_get_inner_dest_code (src);
      *total = COSTS_N_INSNS (msp430_costs (src_inner, dst_inner, speed, x));
      if (mode == SImode)
        *total *= 2;
      if (mode == DImode)
        *total *= 4;
      return false;

    case ROTATE:
    case ASHIFT:
    case ASHIFTRT:
    case LSHIFTRT:
      dst_inner = msp430_get_inner_dest_code (dst);
      src_inner = msp430_get_inner_dest_code (src);
      *total = COSTS_N_INSNS (msp430_shift_costs (src_inner, dst_inner,
                                                  speed, x));
      if (mode == SImode)
        *total *= 2;
      if (mode == DImode)
        *total *= 4;
      return false;

    case MULT:
    case DIV:
    case MOD:
    case UDIV:
    case UMOD:
      dst_inner = msp430_get_inner_dest_code (dst);
      src_inner = msp430_get_inner_dest_code (src);
      *total = COSTS_N_INSNS (msp430_muldiv_costs (src_inner, dst_inner, speed,
                                                   x, mode));
      return false;

    case CALL:
    case SIGN_EXTEND:
      dst_inner = msp430_get_inner_dest_code (dst);
      *total = COSTS_N_INSNS (msp430_single_op_cost (dst_inner, speed, x));
      if (mode == SImode)
        *total *= 2;
      if (mode == DImode)
        *total *= 4;
      return false;

    case CONST_INT:
    case CONST_FIXED:
    case CONST_DOUBLE:
    case SYMBOL_REF:
    case CONST:
    case LABEL_REF:
    case REG:
    case PC:
    case POST_INC:
      if (mode == SImode)
        *total = COSTS_N_INSNS (2);
      else if (mode == DImode)
        *total = COSTS_N_INSNS (4);
      return true;

    case MEM:
      /* PSImode operands are expensive when in memory.  */
      if (mode == PSImode)
        *total = COSTS_N_INSNS (1);
      else if (mode == SImode)
        *total = COSTS_N_INSNS (2);
      else if (mode == DImode)
        *total = COSTS_N_INSNS (4);
      /* Recurse into the MEM.  */
      return false;

    case EQ:
    case NE:
    case GT:
    case GTU:
    case GE:
    case GEU:
    case LT:
    case LTU:
    case LE:
    case LEU:
      /* Conditions are mostly equivalent, changing their relative
         costs has no effect.  */
      return false;

    case ASM_OPERANDS:
    case ASM_INPUT:
    case CLOBBER:
    case COMPARE:
    case CONCAT:
    case ENTRY_VALUE:
      /* Other unhandled expressions.  */
      return false;

    default:
      return false;
    }
}

#undef TARGET_INSN_COST
#define TARGET_INSN_COST msp430_insn_cost

static int
msp430_insn_cost (rtx_insn *insn, bool speed ATTRIBUTE_UNUSED)
{
  if (recog_memoized (insn) < 0)
    return 0;

  /* The returned cost must be relative to COSTS_N_INSNS (1). An insn with a
     length of 2 bytes is the smallest possible size and so must be equivalent
     to COSTS_N_INSNS (1).  */
  return COSTS_N_INSNS (get_attr_length (insn) / 2);

  /* FIXME Add more detailed costs when optimizing for speed.
     For now the length of the instruction is a good approximiation and roughly
     correlates with cycle cost.  */
}

\f
/* Function Entry and Exit */

/* The MSP430 call frame looks like this:

   <higher addresses>
   +--------------------+
   |                    |
   | Stack Arguments    |
   |                    |
   +--------------------+ <-- "arg pointer"
   |                    |
   | PC from call       |  (2 bytes for 430, 4 for TARGET_LARGE)
   |                    |
   +--------------------+
   | SR if this func has|
   | been called via an |
   | interrupt.         |
   +--------------------+  <-- SP before prologue, also AP
   |                    |
   | Saved Regs         |  (2 bytes per reg for 430, 4 per for TARGET_LARGE)
   |                    |
   +--------------------+  <-- "frame pointer"
   |                    |
   | Locals             |
   |                    |
   +--------------------+
   |                    |
   | Outgoing Args      |
   |                    |
   +--------------------+  <-- SP during function
   <lower addresses>

*/

/* We use this to wrap all emitted insns in the prologue, so they get
   the "frame-related" (/f) flag set.  */
static rtx
F (rtx x)
{
  RTX_FRAME_RELATED_P (x) = 1;
  return x;
}

/* This is the one spot that decides if a register is to be saved and
   restored in the prologue/epilogue.  */
static bool
msp430_preserve_reg_p (int regno)
{
  /* PC, SP, SR, and the constant generator.  */
  if (regno <= 3)
    return false;

  /* FIXME: add interrupt, EH, etc.  */
  if (crtl->calls_eh_return)
    return true;

  /* Shouldn't be more than the above, but just in case...  */
  if (fixed_regs[regno])
    return false;

  /* For interrupt functions we must save and restore the used regs that
     would normally be caller-saved (R11->R15).  */
  if (msp430_is_interrupt_func () && regno >= 11 && regno <= 15)
    {
      if (crtl->is_leaf && df_regs_ever_live_p (regno))
        /* If the interrupt func is a leaf then we only need to restore the
           caller-saved regs that are used.  */
        return true;
      else if (!crtl->is_leaf)
        /* If the interrupt function is not a leaf we must save all
           caller-saved regs in case the callee modifies them.  */
        return true;
    }

  if (!call_used_or_fixed_reg_p (regno)
      && df_regs_ever_live_p (regno))
    return true;

  return false;
}

/* Compute all the frame-related fields in our machine_function
   structure.  */
static void
msp430_compute_frame_info (void)
{
  int i;

  cfun->machine->computed = 1;
  cfun->machine->framesize_regs = 0;
  cfun->machine->framesize_locals = get_frame_size ();
  cfun->machine->framesize_outgoing = crtl->outgoing_args_size;

  for (i = 0; i < ARG_POINTER_REGNUM; i ++)
    if (msp430_preserve_reg_p (i))
      {
        cfun->machine->need_to_save[i] = 1;
        cfun->machine->framesize_regs += (TARGET_LARGE ? 4 : 2);
      }
    else
      cfun->machine->need_to_save[i] = 0;

  if ((cfun->machine->framesize_locals + cfun->machine->framesize_outgoing) & 1)
    cfun->machine->framesize_locals ++;

  cfun->machine->framesize = (cfun->machine->framesize_regs
                              + cfun->machine->framesize_locals
                              + cfun->machine->framesize_outgoing);
}

/* Attribute Handling.  */

const char * const  ATTR_INTR   = "interrupt";
const char * const  ATTR_WAKEUP = "wakeup";
const char * const  ATTR_NAKED  = "naked";
const char * const  ATTR_REENT  = "reentrant";
const char * const  ATTR_CRIT   = "critical";
const char * const  ATTR_LOWER  = "lower";
const char * const  ATTR_UPPER  = "upper";
const char * const  ATTR_EITHER = "either";
const char * const  ATTR_NOINIT = "noinit";
const char * const  ATTR_PERSIST = "persistent";

static inline bool
has_attr (const char * attr, tree decl)
{
  if (decl == NULL_TREE)
    return false;
  return lookup_attribute (attr, DECL_ATTRIBUTES (decl)) != NULL_TREE;
}

static bool
is_interrupt_func (tree decl = current_function_decl)
{
  return has_attr (ATTR_INTR, decl);
}

/* Returns true if the current function has the "interrupt" attribute.  */

bool
msp430_is_interrupt_func (void)
{
  return is_interrupt_func (current_function_decl);
}

static bool
is_wakeup_func (tree decl = current_function_decl)
{
  return is_interrupt_func (decl) && has_attr (ATTR_WAKEUP, decl);
}

static inline bool
is_naked_func (tree decl = current_function_decl)
{
  return has_attr (ATTR_NAKED, decl);
}

static inline bool
is_reentrant_func (tree decl = current_function_decl)
{
  return has_attr (ATTR_REENT, decl);
}

static inline bool
is_critical_func (tree decl = current_function_decl)
{
  return has_attr (ATTR_CRIT, decl);
}

static bool
has_section_name (const char * name, tree decl = current_function_decl)
{
  if (decl == NULL_TREE)
    return false;
  return (DECL_SECTION_NAME (decl)
          && (strcmp (name, DECL_SECTION_NAME (decl)) == 0));
}

#undef  TARGET_ALLOCATE_STACK_SLOTS_FOR_ARGS
#define TARGET_ALLOCATE_STACK_SLOTS_FOR_ARGS \
  msp430_allocate_stack_slots_for_args

static bool
msp430_allocate_stack_slots_for_args (void)
{
  /* Naked functions should not allocate stack slots for arguments.  */
  return ! is_naked_func ();
}

#undef TARGET_WARN_FUNC_RETURN
#define TARGET_WARN_FUNC_RETURN msp430_warn_func_return

static bool
msp430_warn_func_return (tree decl)
{
  /* Naked functions are implemented entirely in assembly, including the
     return sequence, so suppress warnings about this.  */
  return !is_naked_func (decl);
}

/* Verify MSP430 specific attributes.  */
#define TREE_NAME_EQ(NAME, STR) (strcmp (IDENTIFIER_POINTER (NAME), (STR)) == 0)

static tree
msp430_attr (tree * node,
             tree   name,
             tree   args,
             int    flags ATTRIBUTE_UNUSED,
             bool * no_add_attrs)
{
  gcc_assert (DECL_P (* node));

  /* Only the interrupt attribute takes an argument.  */
  if (args != NULL)
    {
      tree value = TREE_VALUE (args);

      switch (TREE_CODE (value))
        {
        case STRING_CST:
          if (   strcmp (TREE_STRING_POINTER (value), "reset")
              && strcmp (TREE_STRING_POINTER (value), "nmi")
              && strcmp (TREE_STRING_POINTER (value), "watchdog"))
            /* Allow the attribute to be added - the linker script
               being used may still recognise this name.  */
            warning (OPT_Wattributes,
                     "unrecognized interrupt vector argument of %qE attribute",
                     name);
          break;

        case INTEGER_CST:
          if (wi::gtu_p (wi::to_wide (value), 63))
            /* Allow the attribute to be added - the linker script
               being used may still recognise this value.  */
            warning (OPT_Wattributes,
                     "numeric argument of %qE attribute must be in range [0-63]",
                     name);
          break;

        default:
          warning (OPT_Wattributes,
                   "argument of %qE attribute is not a string constant "
                   "or number", name);
          *no_add_attrs = true;
          break;
        }
    }

  const char * message = NULL;

  if (TREE_CODE (* node) != FUNCTION_DECL)
    {
      message = "%qE attribute only applies to functions";
    }
  else if (TREE_NAME_EQ (name, ATTR_INTR))
    {
      if (TREE_CODE (TREE_TYPE (* node)) == FUNCTION_TYPE
          && ! VOID_TYPE_P (TREE_TYPE (TREE_TYPE (* node))))
        message = "interrupt handlers must be void";
      else
        {
          /* Ensure interrupt handlers never get optimised out.  */
          TREE_USED (* node) = 1;
          DECL_PRESERVE_P (* node) = 1;
        }
      if (is_critical_func (* node))
        {
          /* We always ignore the critical attribute when interrupt and
             critical are used together.  */
          warning (OPT_Wattributes,
                   "critical attribute has no effect on interrupt functions");
          DECL_ATTRIBUTES (*node) = remove_attribute (ATTR_CRIT,
                                                      DECL_ATTRIBUTES (* node));
        }
    }
  else if (TREE_NAME_EQ (name, ATTR_CRIT))
    {
      if (is_interrupt_func ( *node))
        message = "critical attribute has no effect on interrupt functions";
    }

  if (message)
    {
      warning (OPT_Wattributes, message, name);
      * no_add_attrs = true;
    }

  return NULL_TREE;
}

static tree
msp430_section_attr (tree * node,
                     tree   name,
                     tree   args,
                     int    flags ATTRIBUTE_UNUSED,
                     bool * no_add_attrs ATTRIBUTE_UNUSED)
{
  gcc_assert (DECL_P (* node));
  gcc_assert (args == NULL);

  const char * message = NULL;

  /* The "noinit", "persistent", and "section" attributes are handled
     generically, so we cannot set up additional target-specific attribute
     exclusions using the existing mechanism.  */
  if (has_attr (ATTR_NOINIT, *node) && !TREE_NAME_EQ (name, "lower"))
    message = G_("ignoring attribute %qE because it conflicts with "
                 "attribute %<noinit%>");
  else if (has_attr ("section", *node) && !TREE_NAME_EQ (name, "lower"))
    message = G_("ignoring attribute %qE because it conflicts with "
                 "attribute %<section%>");
  else if (has_attr (ATTR_PERSIST, *node) && !TREE_NAME_EQ (name, "lower"))
    message = G_("ignoring attribute %qE because it conflicts with "
                 "attribute %<persistent%>");
  /* It does not make sense to use upper/lower/either attributes without
     -mlarge.
     Without -mlarge, "lower" is the default and only region, so is redundant.
     Without -mlarge, "upper" will (and "either" might) place code/data in the
     upper region, which for data could result in relocation overflows, and for
     code could result in stack mismanagement and incorrect call/return
     instructions.  */
  else if (!TARGET_LARGE)
    message = G_("%qE attribute ignored.  Large memory model (%<-mlarge%>) "
                 "is required.");

  if (message)
    {
      warning (OPT_Wattributes, message, name);
      * no_add_attrs = true;
    }

  return NULL_TREE;
}

/* Helper to define attribute exclusions.  */
#define ATTR_EXCL(name, function, type, variable)       \
  { name, function, type, variable }

/* "reentrant", "critical" and "naked" functions must conflict because
   they all modify the prologue or epilogue of functions in mutually exclusive
   ways.  */
static const struct attribute_spec::exclusions attr_reent_exclusions[] =
{
  ATTR_EXCL (ATTR_NAKED, true, true, true),
  ATTR_EXCL (ATTR_CRIT, true, true, true),
  ATTR_EXCL (NULL, false, false, false)
};

static const struct attribute_spec::exclusions attr_naked_exclusions[] =
{
  ATTR_EXCL (ATTR_REENT, true, true, true),
  ATTR_EXCL (ATTR_CRIT, true, true, true),
  ATTR_EXCL (NULL, false, false, false)
};

static const struct attribute_spec::exclusions attr_crit_exclusions[] =
{
  ATTR_EXCL (ATTR_REENT, true, true, true),
  ATTR_EXCL (ATTR_NAKED, true, true, true),
  ATTR_EXCL (NULL, false, false, false)
};

/* Attributes which put the given object in a specific section must conflict
   with one another.  */
static const struct attribute_spec::exclusions attr_lower_exclusions[] =
{
  ATTR_EXCL (ATTR_UPPER, true, true, true),
  ATTR_EXCL (ATTR_EITHER, true, true, true),
  ATTR_EXCL (NULL, false, false, false)
};

static const struct attribute_spec::exclusions attr_upper_exclusions[] =
{
  ATTR_EXCL (ATTR_LOWER, true, true, true),
  ATTR_EXCL (ATTR_EITHER, true, true, true),
  ATTR_EXCL (NULL, false, false, false)
};

static const struct attribute_spec::exclusions attr_either_exclusions[] =
{
  ATTR_EXCL (ATTR_LOWER, true, true, true),
  ATTR_EXCL (ATTR_UPPER, true, true, true),
  ATTR_EXCL (NULL, false, false, false)
};

#undef  TARGET_ATTRIBUTE_TABLE
#define TARGET_ATTRIBUTE_TABLE          msp430_attribute_table

/* Table of MSP430-specific attributes.  */
const struct attribute_spec msp430_attribute_table[] =
  {
    /* { name, min_num_args, max_num_args, decl_req, type_req, fn_type_req,
         affects_type_identity, handler, exclude } */
    { ATTR_INTR,        0, 1, true,  false, false, false, msp430_attr, NULL },
    { ATTR_NAKED,       0, 0, true,  false, false, false, msp430_attr,
      attr_naked_exclusions },
    { ATTR_REENT,       0, 0, true,  false, false, false, msp430_attr,
      attr_reent_exclusions },
    { ATTR_CRIT,        0, 0, true,  false, false, false, msp430_attr,
      attr_crit_exclusions },
    { ATTR_WAKEUP,      0, 0, true,  false, false, false, msp430_attr, NULL },

    { ATTR_LOWER,       0, 0, true,  false, false, false, msp430_section_attr,
      attr_lower_exclusions },
    { ATTR_UPPER,       0, 0, true,  false, false, false, msp430_section_attr,
      attr_upper_exclusions },
    { ATTR_EITHER,      0, 0, true,  false, false, false, msp430_section_attr,
      attr_either_exclusions },

    { NULL,             0, 0, false, false, false, false, NULL,  NULL }
  };

#undef TARGET_HANDLE_GENERIC_ATTRIBUTE
#define TARGET_HANDLE_GENERIC_ATTRIBUTE msp430_handle_generic_attribute

tree
msp430_handle_generic_attribute (tree *node,
                                 tree   name,
                                 tree   args ATTRIBUTE_UNUSED,
                                 int    flags ATTRIBUTE_UNUSED,
                                 bool *no_add_attrs)

{
  const char *message = NULL;

  /* Permit the "lower" attribute to be set on variables with the "section",
     "noinit" and "persistent" attributes.  This is used to indicate that the
     corresponding output section will be in lower memory, so a 430X
     instruction is not required to handle it.  */
  if (has_attr (ATTR_LOWER, *node)
      && !(TREE_NAME_EQ (name, "section") || TREE_NAME_EQ (name, ATTR_PERSIST)
           || TREE_NAME_EQ (name, ATTR_NOINIT)))
    message = G_("ignoring attribute %qE because it conflicts with "
                 "attribute %<lower%>");
  else if (has_attr (ATTR_UPPER, *node))
    message = G_("ignoring attribute %qE because it conflicts with "
                 "attribute %<upper%>");
  else if (has_attr (ATTR_EITHER, *node))
    message = G_("ignoring attribute %qE because it conflicts with "
                 "attribute %<either%>");

  if (message)
    {
      warning (OPT_Wattributes, message, name);
      *no_add_attrs = true;
    }

  return NULL_TREE;
}

/* Given a non-automatic VAR_DECL which can possibly have a section, return
   true if the variable will definitely be placed in the lower memory
   region (below address 0x10000).  */
static bool
msp430_var_in_low_mem (tree decl)
{
  gcc_assert (VAR_P (decl));

  /* "noinit" variables are always placed in the lower memory region.  */
  if (has_attr (ATTR_UPPER, decl)
      || has_attr (ATTR_EITHER, decl)
      || has_attr (ATTR_PERSIST, decl)
      /* Unless the variable is marked with the lower or noinit attribute, we
         cannot assume that it is in the lower region if it is marked with the
         section attribute or -mdata-region={upper,either,none} have been
         passed.
         The noinit and section attributes conflict.  */
      || (!has_attr (ATTR_LOWER, decl) && !has_attr (ATTR_NOINIT, decl)
          && (has_attr ("section", decl)
              || msp430_data_region == MSP430_REGION_UPPER
              || msp430_data_region == MSP430_REGION_EITHER
              || msp430_data_region == MSP430_REGION_ANY)))
    return false;
  return true;
}

#undef TARGET_ENCODE_SECTION_INFO
#define TARGET_ENCODE_SECTION_INFO msp430_encode_section_info

/* Encode whether a SYMBOL_REF is definitely in the lower memory region.  */
static void
msp430_encode_section_info (tree decl, rtx rtl, int first)
{
  rtx symbol;
  default_encode_section_info (decl, rtl, first);

  /* Careful not to prod global register variables.  */
  if (!MEM_P (rtl))
    return;
  symbol = XEXP (rtl, 0);
  if (GET_CODE (symbol) != SYMBOL_REF)
    return;

  if (VAR_P (decl)
      && (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
      && msp430_var_in_low_mem (decl))
    SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOW_MEM;
}

#undef  TARGET_ASM_FUNCTION_PROLOGUE
#define TARGET_ASM_FUNCTION_PROLOGUE    msp430_start_function

static void
msp430_start_function (FILE *outfile)
{
  int r, n;

  fprintf (outfile, "; start of function\n");

  if (DECL_ATTRIBUTES (current_function_decl) != NULL_TREE)
    {
      fprintf (outfile, "; attributes: ");
      if (is_naked_func ())
        fprintf (outfile, "naked ");
      if (msp430_is_interrupt_func ())
        fprintf (outfile, "interrupt ");
      if (is_reentrant_func ())
        fprintf (outfile, "reentrant ");
      if (is_critical_func ())
        fprintf (outfile, "critical ");
      if (is_wakeup_func ())
        fprintf (outfile, "wakeup ");
      fprintf (outfile, "\n");
    }

  fprintf (outfile, "; framesize_regs:     %d\n",
           cfun->machine->framesize_regs);
  fprintf (outfile, "; framesize_locals:   %d\n",
           cfun->machine->framesize_locals);
  fprintf (outfile, "; framesize_outgoing: %d\n",
           cfun->machine->framesize_outgoing);
  fprintf (outfile, "; framesize:          %d\n", cfun->machine->framesize);
  fprintf (outfile, "; elim ap -> fp       %d\n",
           msp430_initial_elimination_offset (ARG_POINTER_REGNUM,
                                              FRAME_POINTER_REGNUM));
  fprintf (outfile, "; elim fp -> sp       %d\n",
           msp430_initial_elimination_offset (FRAME_POINTER_REGNUM,
                                              STACK_POINTER_REGNUM));

  n = 0;
  fprintf (outfile, "; saved regs:");
  for (r = 0; r < ARG_POINTER_REGNUM; r++)
    if (cfun->machine->need_to_save[r])
      {
        fprintf (outfile, " %s", reg_names[r]);
        n = 1;
      }
  if (n == 0)
    fprintf (outfile, "(none)");
  fprintf (outfile, "\n");
}

/* Common code to change the stack pointer.  */
static void
increment_stack (HOST_WIDE_INT amount)
{
  rtx inc;
  rtx sp =  stack_pointer_rtx;

  if (amount == 0)
    return;

  if (amount < 0)
    {
      inc = GEN_INT (- amount);
      if (TARGET_LARGE)
        F (emit_insn (gen_subpsi3 (sp, sp, inc)));
      else
        F (emit_insn (gen_subhi3 (sp, sp, inc)));
    }
  else
    {
      inc = GEN_INT (amount);
      if (TARGET_LARGE)
        F (emit_insn (gen_addpsi3 (sp, sp, inc)));
      else
        F (emit_insn (gen_addhi3 (sp, sp, inc)));
    }
}

void
msp430_start_function (FILE *file, const char *name, tree decl)
{
  tree int_attr;

  int_attr = lookup_attribute ("interrupt", DECL_ATTRIBUTES (decl));
  if (int_attr != NULL_TREE)
    {
      tree intr_vector = TREE_VALUE (int_attr);

      if (intr_vector != NULL_TREE)
        {
          char buf[101];

          /* Interrupt vector sections should be unique, but use of weak
             functions implies multiple definitions.  */
          if (DECL_WEAK (decl))
            {
              error ("argument to interrupt attribute is unsupported for weak "
                     "functions");
            }

          intr_vector = TREE_VALUE (intr_vector);

          /* The interrupt attribute has a vector value.  Turn this into a
             section name, switch to that section and put the address of
             the current function into that vector slot.  Note msp430_attr()
             has already verified the vector name for us.  */
          if (TREE_CODE (intr_vector) == STRING_CST)
            sprintf (buf, "__interrupt_vector_%.80s",
                     TREE_STRING_POINTER (intr_vector));
          else /* TREE_CODE (intr_vector) == INTEGER_CST */
            sprintf (buf, "__interrupt_vector_%u",
                     (unsigned int) TREE_INT_CST_LOW (intr_vector));

          switch_to_section (get_section (buf, SECTION_CODE, decl));
          fputs ("\t.word\t", file);
          assemble_name (file, name);
          fputc ('\n', file);
          fputc ('\t', file);
        }
    }

  switch_to_section (function_section (decl));
  ASM_OUTPUT_TYPE_DIRECTIVE (file, name, "function");
  ASM_OUTPUT_FUNCTION_LABEL (file, name, decl);
}

static const char * const lower_prefix = ".lower";
static const char * const upper_prefix = ".upper";
static const char * const either_prefix = ".either";

/* Generate a prefix for a section name, based upon
   the region into which the object should be placed.  */

static const char *
gen_prefix (tree decl)
{
  if (DECL_ONE_ONLY (decl))
    return NULL;

  /* If the user has specified a particular section then do not use any
     prefix.  */
  if (has_attr ("section", decl))
    return NULL;

  /* If the function has been put in the .lowtext section (because it is an
     interrupt handler, and the large memory model is used), then do not add
     any prefixes.  */
  if (has_section_name (".lowtext", decl))
    return NULL;

  /* Memory regions require the large memory model.  */
  if (!TARGET_LARGE)
    return NULL;

  /* Note that we always apply the lower prefix when the attribute has been
     used.  But we only apply the lower prefix when the lower region has been
     specified by a command line option if -muse-lower-region-prefix has also
     been passed.  */
  if (has_attr (ATTR_LOWER, decl))
    return lower_prefix;

  if (has_attr (ATTR_UPPER, decl))
    return upper_prefix;

  if (has_attr (ATTR_EITHER, decl))
    return either_prefix;

  if (TREE_CODE (decl) == FUNCTION_DECL)
    {
      if ((msp430_code_region == MSP430_REGION_LOWER)
          && TARGET_USE_LOWER_REGION_PREFIX)
        return lower_prefix;

      if (msp430_code_region == MSP430_REGION_UPPER)
        return upper_prefix;

      if (msp430_code_region == MSP430_REGION_EITHER)
        return either_prefix;
    }
  else
    {
      if ((msp430_data_region == MSP430_REGION_LOWER)
          && TARGET_USE_LOWER_REGION_PREFIX)
        return lower_prefix;

      if (msp430_data_region == MSP430_REGION_UPPER)
        return upper_prefix;

      if (msp430_data_region == MSP430_REGION_EITHER)
        return either_prefix;
    }

  return NULL;
}

#undef  TARGET_ASM_SELECT_SECTION
#define TARGET_ASM_SELECT_SECTION msp430_select_section

static section *
msp430_select_section (tree decl, int reloc, unsigned HOST_WIDE_INT align)
{
  const char *prefix;
  const char *sec_name;
  const char *base_sec_name;

  gcc_assert (decl != NULL_TREE);

  if (TREE_CODE (decl) == STRING_CST
      || TREE_CODE (decl) == CONSTRUCTOR
      || TREE_CODE (decl) == INTEGER_CST
      || TREE_CODE (decl) == VECTOR_CST
      || TREE_CODE (decl) == COMPLEX_CST)
    return default_select_section (decl, reloc, align);

  /* In large mode we must make sure that interrupt handlers are put into
     low memory as the vector table only accepts 16-bit addresses.  */
  if (TARGET_LARGE && TREE_CODE (decl) == FUNCTION_DECL
      && is_interrupt_func (decl))
    return get_section (".lowtext", SECTION_CODE | SECTION_WRITE , decl);

  /* The "noinit" and "persistent" attributes are handled generically.  */
  if (has_attr (ATTR_NOINIT, decl) || has_attr (ATTR_PERSIST, decl))
    return default_elf_select_section (decl, reloc, align);

  prefix = gen_prefix (decl);

  switch (categorize_decl_for_section (decl, reloc))
    {
    case SECCAT_TEXT:
      if (!prefix)
        return text_section;
      base_sec_name = ".text";
      break;
    case SECCAT_DATA:
      if (!prefix)
        return data_section;
      base_sec_name = ".data";
      break;
    case SECCAT_BSS:
      if (!prefix)
        return bss_section;
      base_sec_name = ".bss";
      break;
    case SECCAT_RODATA:
      if (!prefix)
        return readonly_data_section;
      base_sec_name = ".rodata";
      break;

    /* Enable merging of constant data by the GNU linker using
       default_elf_select_section and therefore enabling creation of
       sections with the SHF_MERGE flag.  */
    case SECCAT_RODATA_MERGE_STR:
    case SECCAT_RODATA_MERGE_STR_INIT:
    case SECCAT_RODATA_MERGE_CONST:
      return default_elf_select_section (decl, reloc, align);

    /* The sections listed below are not supported for MSP430.
       They should not be generated, but in case they are, we use
       default_select_section so they get placed in sections
       the msp430 assembler and linker understand.  */
    /* "small data" sections are not supported.  */
    case SECCAT_SRODATA:
    case SECCAT_SDATA:
    case SECCAT_SBSS:
    /* Thread-local storage (TLS) is not supported.  */
    case SECCAT_TDATA:
    case SECCAT_TBSS:
    /* Sections used by a dynamic linker are not supported.  */
    case SECCAT_DATA_REL:
    case SECCAT_DATA_REL_LOCAL:
    case SECCAT_DATA_REL_RO:
    case SECCAT_DATA_REL_RO_LOCAL:
      return default_select_section (decl, reloc, align);

    default:
      gcc_unreachable ();
    }

  sec_name = ACONCAT ((prefix, base_sec_name, DECL_SECTION_NAME (decl), NULL));

  return get_named_section (decl, sec_name, 0);
}

#undef  TARGET_ASM_FUNCTION_SECTION
#define TARGET_ASM_FUNCTION_SECTION msp430_function_section

static section *
msp430_function_section (tree decl, enum node_frequency freq, bool startup,
                         bool exit)
{
  const char * name;

  gcc_assert (DECL_SECTION_NAME (decl) != NULL);
  name = DECL_SECTION_NAME (decl);

  const char * prefix = gen_prefix (decl);
  if (prefix == NULL
      || startswith (name, prefix))
    return default_function_section (decl, freq, startup, exit);

  name = ACONCAT ((prefix, name, NULL));
  return get_named_section (decl, name, 0);
}

#undef  TARGET_SECTION_TYPE_FLAGS
#define TARGET_SECTION_TYPE_FLAGS msp430_section_type_flags

unsigned int
msp430_section_type_flags (tree decl, const char * name, int reloc)
{
  if (startswith (name, lower_prefix))
    name += strlen (lower_prefix);
  else if (startswith (name, upper_prefix))
    name += strlen (upper_prefix);
  else if (startswith (name, either_prefix))
    name += strlen (either_prefix);

  return default_section_type_flags (decl, name, reloc);
}

#undef  TARGET_ASM_UNIQUE_SECTION
#define TARGET_ASM_UNIQUE_SECTION msp430_unique_section

static void
msp430_unique_section (tree decl, int reloc)
{
  gcc_assert (decl != NULL_TREE);

  /* In large mode we must make sure that interrupt handlers are put into
     low memory as the vector table only accepts 16-bit addresses.  */
  if (TARGET_LARGE && TREE_CODE (decl) == FUNCTION_DECL
      && is_interrupt_func (decl))
    {
      set_decl_section_name (decl, ".lowtext");
      return;
    }

  default_unique_section (decl, reloc);

  const char * prefix;

  if (   TREE_CODE (decl) == STRING_CST
      || TREE_CODE (decl) == CONSTRUCTOR
      || TREE_CODE (decl) == INTEGER_CST
      || TREE_CODE (decl) == VECTOR_CST
      || TREE_CODE (decl) == COMPLEX_CST
      || (prefix = gen_prefix (decl)) == NULL)
    return;

  const char * dec_name = DECL_SECTION_NAME (decl);
  char * name = ACONCAT ((prefix, dec_name, NULL));

  set_decl_section_name (decl, name);
}

/* Emit a declaration of a common symbol.
   If a data region is in use then put the symbol into the
   equivalent .bss section instead.
   If LOCAL is 1, then DECL is for a local common variable.  */
void
msp430_output_aligned_decl_common (FILE *                 stream,
                                   const tree             decl,
                                   const char *           name,
                                   unsigned HOST_WIDE_INT size,
                                   unsigned int           align,
                                   int local)
{
  /* Only emit a common symbol if the variable does not have a specific section
     assigned.  */
  if ((msp430_data_region == MSP430_REGION_ANY
       || ((msp430_data_region == MSP430_REGION_LOWER)
           && !TARGET_USE_LOWER_REGION_PREFIX))
      && !(decl != NULL_TREE && DECL_SECTION_NAME (decl))
      && !has_attr (ATTR_EITHER, decl)
      && !has_attr (ATTR_LOWER, decl)
      && !has_attr (ATTR_UPPER, decl)
      && !has_attr (ATTR_PERSIST, decl)
      && !has_attr (ATTR_NOINIT, decl))
    {
      if (local)
        {
          fprintf (stream, LOCAL_ASM_OP);
          assemble_name (stream, name);
          fprintf (stream, "\n");
        }
      fprintf (stream, COMMON_ASM_OP);
      assemble_name (stream, name);
      fprintf (stream, "," HOST_WIDE_INT_PRINT_UNSIGNED",%u\n",
               size, align / BITS_PER_UNIT);
    }
  else
    {
      section * sec;

      if (decl)
        sec = msp430_select_section (decl, 0, align);
      else
        switch (msp430_data_region)
          {
          case MSP430_REGION_UPPER:
            sec = get_named_section (NULL, ".upper.bss", 0);
            break;
          case MSP430_REGION_LOWER:
            sec = get_named_section (NULL, ".lower.bss", 0);
            break;
          case MSP430_REGION_EITHER:
            sec = get_named_section (NULL, ".either.bss", 0);
            break;
          default:
            gcc_unreachable ();
          }
      gcc_assert (sec != NULL);

      switch_to_section (sec);
      ASM_OUTPUT_ALIGN (stream, floor_log2 (align / BITS_PER_UNIT));
      if (!local)
        {
          targetm.asm_out.globalize_label (stream, name);
          ASM_WEAKEN_LABEL (stream, name);
        }
      ASM_OUTPUT_LABEL (stream, name);
      ASM_OUTPUT_SKIP (stream, size ? size : 1);
    }
}

#undef TARGET_ASM_FILE_END
#define TARGET_ASM_FILE_END msp430_file_end

/* Emit MSPABI and GNU object attributes.
   Tags and values for MSPABI attributes are:
   OFBA_MSPABI_Tag_ISA          4
     MSP430     1
     MSP430X    2
   OFBA_MSPABI_Tag_Code_Model   6
     Small      1
     Large      2
   OFBA_MSPABI_Tag_Data_Model   8
     Small      1
     Large      2
     Restricted 3 (Unused by GNU)
   OFBA_MSPABI_Tag_enum_size    10 (Unused by GNU)
   Note that Code_Model and Data_Model are always equal for GNU.
   We define a new .gnu_attribute to keep track of the data region used.
   Tag_GNU_MSP430_Data_Region   4
     LOWER      1
     ANY        2
   See binutils-gdb/include/elf/msp430.h for the full details.  */
static void
msp430_file_end (void)
{
#ifdef HAVE_AS_MSPABI_ATTRIBUTE
  /* Enum for tag names.  */
  enum
    {
      OFBA_MSPABI_Tag_ISA = 4,
      OFBA_MSPABI_Tag_Code_Model = 6,
      OFBA_MSPABI_Tag_Data_Model = 8,
      Tag_GNU_MSP430_Data_Region = 4
    };
  /* Enum for tag values.  */
  enum
    {
      OFBA_MSPABI_Val_ISA_MSP430 = 1,
      OFBA_MSPABI_Val_ISA_MSP430X = 2,
      OFBA_MSPABI_Val_Model_Small = 1,
      OFBA_MSPABI_Val_Model_Large = 2,
      Tag_GNU_MSP430_Data_Region_Lower = 1,
      Tag_GNU_MSP430_Data_Region_Any = 2
    };
  /* .mspabi_attribute is a GNU assembler directive only.  The assembler will
     construct a .MSP430.attributes section based on the options it is invoked
     with.  The values it reads from these directives are used for validating
     those options.  */
  const char *msp430_attr = ".mspabi_attribute";
  const char *gnu_attr = ".gnu_attribute";

  /* Emit .mspabi_attribute directive for OFBA_MSPABI_Tag_ISA.  */
  fprintf (asm_out_file, "\t%s %d, %d\n", msp430_attr, OFBA_MSPABI_Tag_ISA,
           msp430x ? OFBA_MSPABI_Val_ISA_MSP430X : OFBA_MSPABI_Val_ISA_MSP430);
  /* Emit .mspabi_attribute directive for OFBA_MSPABI_Tag_Code_Model.  */
  fprintf (asm_out_file, "\t%s %d, %d\n", msp430_attr,
           OFBA_MSPABI_Tag_Code_Model,
           TARGET_LARGE ? OFBA_MSPABI_Val_Model_Large
           : OFBA_MSPABI_Val_Model_Small);
  /* Emit .mspabi_attribute directive for OFBA_MSPABI_Tag_Data_Model.  */
  fprintf (asm_out_file, "\t%s %d, %d\n", msp430_attr,
           OFBA_MSPABI_Tag_Data_Model,
           TARGET_LARGE ? OFBA_MSPABI_Val_Model_Large
           : OFBA_MSPABI_Val_Model_Small);
#ifdef HAVE_AS_GNU_ATTRIBUTE
  /* Emit .gnu_attribute directive for Tag_GNU_MSP430_Data_Region.  */
  fprintf (asm_out_file, "\t%s %d, %d\n", gnu_attr, Tag_GNU_MSP430_Data_Region,
           msp430_data_region == MSP430_REGION_LOWER
           ? Tag_GNU_MSP430_Data_Region_Lower
           : Tag_GNU_MSP430_Data_Region_Any);
#endif
#endif
}

enum msp430_builtin
{
  MSP430_BUILTIN_BIC_SR,
  MSP430_BUILTIN_BIS_SR,
  MSP430_BUILTIN_DELAY_CYCLES,
  MSP430_BUILTIN_max
};

static GTY(()) tree msp430_builtins[(int) MSP430_BUILTIN_max];

static void
msp430_init_builtins (void)
{
  tree void_ftype_int = build_function_type_list (void_type_node,
                                                  integer_type_node, NULL);
  tree void_ftype_longlong
    = build_function_type_list (void_type_node, long_long_integer_type_node,
                                NULL);

  msp430_builtins[MSP430_BUILTIN_BIC_SR] =
    add_builtin_function ( "__bic_SR_register_on_exit", void_ftype_int,
                          MSP430_BUILTIN_BIC_SR, BUILT_IN_MD, NULL, NULL_TREE);

  msp430_builtins[MSP430_BUILTIN_BIS_SR] =
    add_builtin_function ( "__bis_SR_register_on_exit", void_ftype_int,
                          MSP430_BUILTIN_BIS_SR, BUILT_IN_MD, NULL, NULL_TREE);

  msp430_builtins[MSP430_BUILTIN_DELAY_CYCLES] =
    add_builtin_function ( "__delay_cycles", void_ftype_longlong,
                          MSP430_BUILTIN_DELAY_CYCLES, BUILT_IN_MD, NULL,
                          NULL_TREE);
}

static tree
msp430_builtin_decl (unsigned code, bool initialize ATTRIBUTE_UNUSED)
{
  switch (code)
    {
    case MSP430_BUILTIN_BIC_SR:
    case MSP430_BUILTIN_BIS_SR:
    case MSP430_BUILTIN_DELAY_CYCLES:
      return msp430_builtins[code];
    default:
      return error_mark_node;
    }
}

/* These constants are really register reads, which are faster than
   regular constants.  */
static int
cg_magic_constant (HOST_WIDE_INT c)
{
  switch (c)
    {
    case 0xffff:
    case -1:
    case 0:
    case 1:
    case 2:
    case 4:
    case 8:
      return 1;
    default:
      return 0;
    }
}

static rtx
msp430_expand_delay_cycles (rtx arg)
{
  HOST_WIDE_INT i, c, n;
  /* extra cycles for MSP430X instructions */
#define CYCX(M,X) (msp430x ? (X) : (M))

  if (GET_CODE (arg) != CONST_INT)
    {
      error ("%<__delay_cycles%> only takes constant arguments");
      return NULL_RTX;
    }

  c = INTVAL (arg);

  if (HOST_BITS_PER_WIDE_INT > 32)
    {
      if (c < 0)
        {
          error ("%<__delay_cycles%> only takes non-negative cycle counts");
          return NULL_RTX;
        }
    }

  emit_insn (gen_delay_cycles_start (arg));

  /* For 32-bit loops, there's 13(16) + 5(min(x,0x10000) + 6x cycles.  */
  if (c > 3 * 0xffff + CYCX (7, 10))
    {
      n = c;
      /* There's 4 cycles in the short (i>0xffff) loop and 7 in the long
         (x<=0xffff) loop.  */
      if (c >= 0x10000 * 7 + CYCX (14, 16))
        {
          i = 0x10000;
          c -= CYCX (14, 16) + 7 * 0x10000;
          i += c / 4;
          c %= 4;
          if ((unsigned long long) i > 0xffffffffULL)
            {
              error ("%<__delay_cycles%> is limited to 32-bit loop counts");
              return NULL_RTX;
            }
        }
      else
        {
          i = (c - CYCX (14, 16)) / 7;
          c -= CYCX (14, 16) + i * 7;
        }

      if (cg_magic_constant (i & 0xffff))
        c ++;
      if (cg_magic_constant ((i >> 16) & 0xffff))
        c ++;

      if (msp430x)
        emit_insn (gen_delay_cycles_32x (GEN_INT (i), GEN_INT (n - c)));
      else
        emit_insn (gen_delay_cycles_32 (GEN_INT (i), GEN_INT (n - c)));
    }

  /* For 16-bit loops, there's 7(10) + 3x cycles - so the max cycles is
     0x30004(7).  */
  if (c > 12)
    {
      n = c;
      i = (c - CYCX (7, 10)) / 3;
      c -= CYCX (7, 10) + i * 3;

      if (cg_magic_constant (i))
        c ++;

      if (msp430x)
        emit_insn (gen_delay_cycles_16x (GEN_INT (i), GEN_INT (n - c)));
      else
        emit_insn (gen_delay_cycles_16 (GEN_INT (i), GEN_INT (n - c)));
    }

  while (c > 1)
    {
      emit_insn (gen_delay_cycles_2 ());
      c -= 2;
    }

  if (c)
    {
      emit_insn (gen_delay_cycles_1 ());
      c -= 1;
    }

  emit_insn (gen_delay_cycles_end (arg));

  return NULL_RTX;
}

static rtx
msp430_expand_builtin (tree exp,
                       rtx target ATTRIBUTE_UNUSED,
                       rtx subtarget ATTRIBUTE_UNUSED,
                       machine_mode mode ATTRIBUTE_UNUSED,
                       int ignore ATTRIBUTE_UNUSED)
{
  tree fndecl = TREE_OPERAND (CALL_EXPR_FN (exp), 0);
  unsigned int fcode = DECL_MD_FUNCTION_CODE (fndecl);
  rtx arg1 = expand_normal (CALL_EXPR_ARG (exp, 0));

  if (fcode == MSP430_BUILTIN_DELAY_CYCLES)
    return msp430_expand_delay_cycles (arg1);

  if (! msp430_is_interrupt_func ())
    {
      error ("MSP430 built-in functions only work inside interrupt handlers");
      return NULL_RTX;
    }

  if (! REG_P (arg1) && ! CONSTANT_P (arg1))
    arg1 = force_reg (mode, arg1);

  switch (fcode)
    {
    case MSP430_BUILTIN_BIC_SR:  emit_insn (gen_bic_SR (arg1)); break;
    case MSP430_BUILTIN_BIS_SR:  emit_insn (gen_bis_SR (arg1)); break;
    default:
      internal_error ("bad builtin code");
      break;
    }
  return NULL_RTX;
}

#undef  TARGET_INIT_BUILTINS
#define TARGET_INIT_BUILTINS  msp430_init_builtins

#undef  TARGET_EXPAND_BUILTIN
#define TARGET_EXPAND_BUILTIN msp430_expand_builtin

#undef  TARGET_BUILTIN_DECL
#define TARGET_BUILTIN_DECL   msp430_builtin_decl

void
msp430_expand_prologue (void)
{
  int i, j;
  int fs;
  /* Always use stack_pointer_rtx instead of calling
     rtx_gen_REG ourselves.  Code elsewhere in GCC assumes
     that there is a single rtx representing the stack pointer,
     namely stack_pointer_rtx, and uses == to recognize it.  */
  rtx sp = stack_pointer_rtx;
  rtx p;

  if (is_naked_func ())
    {
      /* We must generate some RTX as thread_prologue_and_epilogue_insns()
         examines the output of the gen_prologue() function.  */
      emit_insn (gen_rtx_CLOBBER (VOIDmode, GEN_INT (0)));
      return;
    }

  emit_insn (gen_prologue_start_marker ());

  if (is_critical_func ())
    {
      emit_insn (gen_push_intr_state ());
      emit_insn (gen_disable_interrupts ());
    }
  else if (is_reentrant_func ())
    emit_insn (gen_disable_interrupts ());

  if (!cfun->machine->computed)
    msp430_compute_frame_info ();

  if (flag_stack_usage_info)
    current_function_static_stack_size = cfun->machine->framesize;

  if (crtl->args.pretend_args_size)
    {
      rtx note;

      gcc_assert (crtl->args.pretend_args_size == 2);

      p = emit_insn (gen_grow_and_swap ());

      /* Document the stack decrement...  */
      note = F (gen_rtx_SET (stack_pointer_rtx,
                             gen_rtx_MINUS (Pmode,
                                            stack_pointer_rtx, GEN_INT (2))));
      add_reg_note (p, REG_FRAME_RELATED_EXPR, note);

      /* ...and the establishment of a new location for the return address.  */
      note = F (gen_rtx_SET (gen_rtx_MEM (Pmode,
                                          gen_rtx_PLUS (Pmode,
                                                        stack_pointer_rtx,
                                                        GEN_INT (-2))),
                             pc_rtx));
      add_reg_note (p, REG_CFA_OFFSET, note);
      F (p);
    }

  for (i = 15; i >= 4; i--)
    if (cfun->machine->need_to_save[i])
      {
        /* We need to save COUNT sequential registers starting from regnum
           I.  */
        int seq, count;
        rtx note;

        for (seq = i - 1; seq >= 4 && cfun->machine->need_to_save[seq]; seq --)
          ;
        count = i - seq;

        if (msp430x)
          {
            /* Note: with TARGET_LARGE we still use PUSHM as PUSHX.A is two
               bytes bigger.  */
            p = F (emit_insn (gen_pushm (gen_rtx_REG (Pmode, i),
                                         GEN_INT (count))));

            /* Document the stack decrement as a result of PUSHM.  */
            note = gen_rtx_SEQUENCE (VOIDmode, rtvec_alloc (count + 1));

            XVECEXP (note, 0, 0)
              = F (gen_rtx_SET (stack_pointer_rtx,
                                gen_rtx_PLUS (Pmode,
                                              stack_pointer_rtx,
                                              GEN_INT (count * (TARGET_LARGE
                                                                ? -4 : -2)))));

            /* *sp-- = R[i-j] */
            /* sp+N     R10
               ...
               sp       R4  */
            for (j = 0; j < count; j ++)
              {
                rtx addr;
                int ofs = (count - j - 1) * (TARGET_LARGE ? 4 : 2);

                if (ofs)
                  addr = gen_rtx_PLUS (Pmode, sp, GEN_INT (ofs));
                else
                  addr = stack_pointer_rtx;

                XVECEXP (note, 0, j + 1) =
                  F (gen_rtx_SET (gen_rtx_MEM (Pmode, addr),
                                  gen_rtx_REG (Pmode, i - j)));
              }

            add_reg_note (p, REG_FRAME_RELATED_EXPR, note);
            i -= count - 1;
          }
        else
          F (emit_insn (gen_push (gen_rtx_REG (Pmode, i))));
      }

  if (frame_pointer_needed)
    F (emit_move_insn (gen_rtx_REG (Pmode, FRAME_POINTER_REGNUM), sp));

  fs = cfun->machine->framesize_locals + cfun->machine->framesize_outgoing;

  increment_stack (- fs);

  emit_insn (gen_prologue_end_marker ());
}

void
msp430_expand_epilogue (int is_eh)
{
  int i, j;
  int fs;
  rtx sp = stack_pointer_rtx;
  rtx p;
  int helper_n = 0;

  if (is_naked_func ())
    {
      /* We must generate some RTX as thread_prologue_and_epilogue_insns()
         examines the output of the gen_epilogue() function.  */
      emit_insn (gen_rtx_CLOBBER (VOIDmode, GEN_INT (0)));
      return;
    }

  if (cfun->machine->need_to_save[10])
    {
      /* Check for a helper function.  */
      helper_n = 7; /* For when the loop below never sees a match.  */
      for (i = 9; i >= 4; i--)
        if (!cfun->machine->need_to_save[i])
          {
            helper_n = 10 - i;
            for (; i >= 4; i--)
              if (cfun->machine->need_to_save[i])
                {
                  helper_n = 0;
                  break;
                }
            break;
          }
    }

  emit_insn (gen_epilogue_start_marker ());

  if (cfun->decl && strcmp (IDENTIFIER_POINTER (DECL_NAME (cfun->decl)),
                            "main") == 0)
    emit_insn (gen_msp430_refsym_need_exit ());

  if (is_wakeup_func ())
    /* Clear the SCG1, SCG0, OSCOFF and CPUOFF bits in the saved copy of the
       status register current residing on the stack.  When this function
       executes its RETI instruction the SR will be updated with this saved
       value, thus ensuring that the processor is woken up from any low power
       state in which it may be residing.  */
    emit_insn (gen_bic_SR (GEN_INT (0xf0)));

  fs = cfun->machine->framesize_locals + cfun->machine->framesize_outgoing;

  increment_stack (fs);

  if (is_eh)
    {
      /* We need to add the right "SP" register save just after the
         regular ones, so that when we pop it off we're in the EH
         return frame, not this one.  This overwrites our own return
         address, but we're not going to be returning anyway.  */
      rtx r12 = gen_rtx_REG (Pmode, 12);
      rtx (*addPmode)(rtx, rtx, rtx) = TARGET_LARGE ? gen_addpsi3 : gen_addhi3;

      /* R12 will hold the new SP.  */
      i = cfun->machine->framesize_regs;
      emit_move_insn (r12, stack_pointer_rtx);
      emit_insn (addPmode (r12, r12, EH_RETURN_STACKADJ_RTX));
      emit_insn (addPmode (r12, r12, GEN_INT (i)));
      emit_move_insn (gen_rtx_MEM (Pmode, plus_constant (Pmode,
                                                         stack_pointer_rtx,
                                                         i)), r12);
    }

  for (i = 4; i <= 15; i++)
    if (cfun->machine->need_to_save[i])
      {
        /* We need to restore COUNT sequential registers starting from regnum
           I.  */
        int seq;
        int count = 1;
        int helper_used = 0;
        rtx note, addr;

        if (msp430x)
          {
            for (seq = i + 1; seq <= 15 && cfun->machine->need_to_save[seq];
                 seq++)
              ;
            count = seq - i;
          }

        if (msp430x)
          {
            /* Note: With TARGET_LARGE we still use
               POPM as POPX.A is two bytes bigger.  */
            p = F (emit_insn (gen_popm (stack_pointer_rtx, GEN_INT (seq - 1),
                                        GEN_INT (count))));
          }
        else if (i == 11 - helper_n
                 && ! msp430_is_interrupt_func ()
                 && ! is_reentrant_func ()
                 && ! is_critical_func ()
                 && crtl->args.pretend_args_size == 0
                 /* Calling the helper takes as many bytes as the POP;RET
                    sequence.  */
                 && helper_n > 1
                 && !is_eh)
          {
            p = F (emit_jump_insn (gen_epilogue_helper (GEN_INT (helper_n))));
            count = helper_n;
            helper_used = 1;
          }
        else
          p = F (emit_insn (gen_pop (gen_rtx_REG (Pmode, i))));

        /* Document the stack increment as a result of POPM.  */
        note = gen_rtx_SEQUENCE (VOIDmode, rtvec_alloc (count + 1));

        addr = gen_rtx_PLUS (Pmode, stack_pointer_rtx,
                             GEN_INT (count * (TARGET_LARGE ? 4 : 2)));

        XVECEXP (note, 0, 0) = F (gen_rtx_SET (stack_pointer_rtx, addr));


        /* *sp++ = R[i+j] */
        /* sp   R4
           ...
           sp+N R10.  */
        for (j = 0; j < count; j++)
          {
            int ofs = j * (TARGET_LARGE ? 4 : 2);

            if (ofs)
              addr = gen_rtx_PLUS (Pmode, sp, GEN_INT (ofs));
            else
              addr = stack_pointer_rtx;

            XVECEXP (note, 0, j + 1)
              = F (gen_rtx_SET (gen_rtx_MEM (Pmode, addr),
                                gen_rtx_REG (Pmode, i + j)));
          }
        add_reg_note (p, REG_FRAME_RELATED_EXPR, note);
        i += count - 1;

        if (helper_used)
          return;
      }

  if (is_eh)
    {
      /* Also pop SP, which puts us into the EH return frame.  Except
         that you can't "pop" sp, you have to just load it off the
         stack.  */
      emit_move_insn (stack_pointer_rtx, gen_rtx_MEM (Pmode,
                                                      stack_pointer_rtx));
    }

  if (crtl->args.pretend_args_size)
    emit_insn (gen_swap_and_shrink ());

  if (is_critical_func ())
    emit_insn (gen_pop_intr_state ());
  else if (is_reentrant_func ())
    emit_insn (gen_enable_interrupts ());

  emit_jump_insn (gen_msp430_return ());
}

/* Implements EH_RETURN_STACKADJ_RTX.  Saved and used later in
   m32c_emit_eh_epilogue.  */
rtx
msp430_eh_return_stackadj_rtx (void)
{
  if (!cfun->machine->eh_stack_adjust)
    {
      rtx sa;

      sa = gen_rtx_REG (Pmode, 15);
      cfun->machine->eh_stack_adjust = sa;
    }
  return cfun->machine->eh_stack_adjust;
}

/* This function is called before reload, to "fix" the stack in
   preparation for an EH return.  */
void
msp430_expand_eh_return (rtx eh_handler)
{
  /* These are all Pmode */
  rtx ap, sa, ra, tmp;

  ap = arg_pointer_rtx;
  sa = msp430_eh_return_stackadj_rtx ();
  ra = eh_handler;

  tmp = ap;
  tmp = gen_rtx_PLUS (Pmode, ap, sa);
  tmp = plus_constant (Pmode, tmp, TARGET_LARGE ? -4 : -2);
  tmp = gen_rtx_MEM (Pmode, tmp);
  emit_move_insn (tmp, ra);
}

#undef  TARGET_INIT_DWARF_REG_SIZES_EXTRA
#define TARGET_INIT_DWARF_REG_SIZES_EXTRA msp430_init_dwarf_reg_sizes_extra
void
msp430_init_dwarf_reg_sizes_extra (tree address)
{
  int i;
  rtx addr = expand_normal (address);
  rtx mem = gen_rtx_MEM (BLKmode, addr);

  /* This needs to match msp430_unwind_word_mode (above).  */
  if (!msp430x)
    return;

  for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
    {
      unsigned int dnum = DWARF_FRAME_REGNUM (i);
      unsigned int rnum = DWARF2_FRAME_REG_OUT (dnum, 1);

      if (rnum < DWARF_FRAME_REGISTERS)
        {
          HOST_WIDE_INT offset = rnum * GET_MODE_SIZE (QImode);

          emit_move_insn (adjust_address (mem, QImode, offset),
                          gen_int_mode (4, QImode));
        }
    }
}

/* The MSP430 ABI defines a number of helper functions that should be
   used for, for example, 32-bit shifts.  This function is called to
   emit such a function, using the table above to optimize some
   cases.  */
void
msp430_expand_helper (rtx *operands, const char *helper_name,
                      bool const_variants)
{
  rtx c, fusage, fsym;
  char *helper_const = NULL;
  int arg1 = 12;
  int arg2 = 13;
  int arg1sz = 1;
  machine_mode arg0mode = GET_MODE (operands[0]);
  machine_mode arg1mode = GET_MODE (operands[1]);
  machine_mode arg2mode = GET_MODE (operands[2]);
  int expand_mpy = startswith (helper_name, "__mspabi_mpy");
  /* This function has been used incorrectly if CONST_VARIANTS is TRUE for a
     hwmpy function.  */
  gcc_assert (!(expand_mpy && const_variants));

  if (arg1mode != VOIDmode && arg2mode != VOIDmode)
    /* Modes of arguments must be equal if not constants.  */
    gcc_assert (arg1mode == arg2mode);

  if (arg1mode == VOIDmode)
    arg1mode = arg0mode;
  if (arg2mode == VOIDmode)
    arg2mode = arg0mode;

  if (arg1mode == SImode)
    {
      arg2 = 14;
      arg1sz = 2;
    }
  else if (arg1mode == DImode)
    {
      arg1 = 8;
      arg1sz = 4;
      arg2 = 12;
    }

  /* Use the "const_variant" of a shift library function if requested.
     These are faster, but have larger code size.  */
  if (const_variants
      && CONST_INT_P (operands[2])
      && INTVAL (operands[2]) >= 1
      && INTVAL (operands[2]) <= 15)
    {
      /* Note that the INTVAL is limited in value and length by the conditional
         above.  */
      int len = strlen (helper_name) + 4;
      helper_const = (char *) xmalloc (len);
      snprintf (helper_const, len, "%s_%d", helper_name,
                (int) INTVAL (operands[2]));
    }

  /* Setup the arguments to the helper function.  */
  emit_move_insn (gen_rtx_REG (arg1mode, arg1),
                  operands[1]);
  if (!helper_const)
    emit_move_insn (gen_rtx_REG (arg2mode, arg2),
                    operands[2]);

  if (expand_mpy)
    {
      if (msp430_use_f5_series_hwmult ())
        fsym = gen_rtx_SYMBOL_REF (VOIDmode, concat (helper_name,
                                                     "_f5hw", NULL));
      else if (msp430_use_32bit_hwmult ())
        {
          /* When the arguments are 16-bits, the 16-bit hardware multiplier is
             used.  */
          if (arg1mode == HImode)
            fsym = gen_rtx_SYMBOL_REF (VOIDmode, concat (helper_name,
                                                         "_hw", NULL));
          else
            fsym = gen_rtx_SYMBOL_REF (VOIDmode, concat (helper_name,
                                                         "_hw32", NULL));
        }
      else if (msp430_use_16bit_hwmult ())
        fsym = gen_rtx_SYMBOL_REF (VOIDmode, concat (helper_name,
                                                     "_hw", NULL));
      else
        fsym = gen_rtx_SYMBOL_REF (VOIDmode, helper_name);
    }
  else
    fsym = gen_rtx_SYMBOL_REF (VOIDmode,
                               helper_const ? helper_const : helper_name);

  c = gen_call_value_internal (gen_rtx_REG (arg0mode, 12), fsym, GEN_INT (0));

  c = emit_call_insn (c);
  RTL_CONST_CALL_P (c) = 1;

  /* Add register usage information for the arguments to the call.  */
  fusage = NULL;
  use_regs (&fusage, arg1, arg1sz);
  if (!helper_const)
    {
      /* If we are expanding a shift, we only need to use the low register
         for the shift amount.  */
      if (!expand_mpy)
        use_regs (&fusage, arg2, 1);
      else
        use_regs (&fusage, arg2, arg1sz);
    }
  add_function_usage_to (c, fusage);

  emit_move_insn (operands[0],
                  /* Return value will always start in R12.  */
                  gen_rtx_REG (arg0mode, 12));
}

/* Return TRUE if the helper function should be used and FALSE if the shifts
   insns should be emitted inline.  */
static bool
use_helper_for_const_shift (machine_mode mode, HOST_WIDE_INT amt)
{
  const int default_inline_shift = 4;
  /* We initialize the option to 65 so we know if the user set it or not.  */
  int user_set_max_inline = (msp430_max_inline_shift == 65 ? 0 : 1);
  int max_inline = (user_set_max_inline ? msp430_max_inline_shift
                    : default_inline_shift);
  /* 32-bit shifts are roughly twice as costly as 16-bit shifts so we adjust
     the heuristic accordingly.  */
  int max_inline_32 = max_inline / 2;

  if (mode == E_DImode)
    return true;

  /* Don't use helpers for these modes on 430X, when optimizing for speed, or
     when emitting a small number of insns.  */
  if ((mode == E_QImode || mode == E_HImode || mode == E_PSImode)
      && (msp430x
          /* If the user set max_inline then we always obey that number.
             Otherwise we always emit the shifts inline at -O2 and above.  */
          || amt <= max_inline
          || (!user_set_max_inline
              && (optimize >= 2 && !optimize_size))))
    return false;

  /* 430 and 430X codegen for SImode shifts is the same.
     Set a hard limit of 15 for the number of shifts that will be emitted
     inline by default, even at -O2 and above, to prevent code size
     explosion.  */
  if (mode == E_SImode
      && (amt <= max_inline_32
          || (!user_set_max_inline
              && (optimize >= 2 && !optimize_size)
              && amt <= 15)))
    return false;

  return true;
}

/* For shift operations which will use an mspabi helper function, setup the
   call to msp430_expand helper.  Return 1 to indicate we have finished with
   this insn and invoke "DONE".
   Otherwise return 0 to indicate the insn should fallthrough.
   Never FAIL.  */
int
msp430_expand_shift (enum rtx_code code, machine_mode mode, rtx *operands)
{
  /* Always use the helper function when the shift amount is not a
     constant.  */
  if (!CONST_INT_P (operands[2])
      || mode == E_DImode
      || use_helper_for_const_shift (mode, INTVAL (operands[2])))
    {
      const char *helper_name = NULL;
      /* The const variants of mspabi shifts have significantly larger code
         size than the generic version, so use the generic version if
         optimizing for size.  */
      bool const_variant = !optimize_size;
      switch (mode)
        {
        case E_HImode:
          helper_name = (code == ASHIFT ? "__mspabi_slli" :
                         (code == ASHIFTRT ? "__mspabi_srai" :
                          (code == LSHIFTRT ? "__mspabi_srli" :
                           NULL)));
          break;
        case E_PSImode:
          helper_name = (code == ASHIFT ? "__gnu_mspabi_sllp" :
                         (code == ASHIFTRT ? "__gnu_mspabi_srap" :
                          (code == LSHIFTRT ? "__gnu_mspabi_srlp" :
                           NULL)));
          /* No const variant for PSImode shifts FIXME.  */
          const_variant = false;
          break;
        case E_SImode:
          helper_name = (code == ASHIFT ? "__mspabi_slll" :
                         (code == ASHIFTRT ? "__mspabi_sral" :
                          (code == LSHIFTRT ? "__mspabi_srll" :
                           NULL)));
          break;
        case E_DImode:
          helper_name = (code == ASHIFT ? "__mspabi_sllll" :
                         (code == ASHIFTRT ? "__mspabi_srall" :
                          (code == LSHIFTRT ? "__mspabi_srlll" :
                           NULL)));
          /* No const variant for DImode shifts.  */
          const_variant = false;
          break;
        default:
          gcc_unreachable ();
          break;
        }
      gcc_assert (helper_name);
      msp430_expand_helper (operands, helper_name, const_variant);
      return 1;
    }
  /* When returning 0, there must be an insn to match the RTL pattern
     otherwise there will be an unrecognizeable insn.  */
  return 0;
}

/* Helper function to emit a sequence of shift instructions.  The amount of
   shift instructions to emit is in OPERANDS[2].
   For 430 we output copies of identical inline shifts for all modes.
   For 430X it is inneficient to do so for any modes except SI and DI, since we
   can make use of R*M insns or RPT with 430X insns, so this function is only
   used for SImode in that case.  */
int
msp430_output_asm_shift_insns (enum rtx_code code, machine_mode mode,
                               rtx *operands, bool return_length)
{
  int i;
  int amt;
  int max_shift = GET_MODE_BITSIZE (mode) - 1;
  int length = 0;

  gcc_assert (CONST_INT_P (operands[2]));
  amt = INTVAL (operands[2]);

  if (amt == 0 || amt > max_shift)
    {
      if (return_length)
        return 0;
      switch (code)
        {
        case ASHIFT:
          output_asm_insn ("# ignored undefined behaviour left shift "
                           "of %1 by %2", operands);
          break;
        case ASHIFTRT:
          output_asm_insn ("# ignored undefined behaviour arithmetic right "
                           "shift of %1 by %2", operands);
          break;
        case LSHIFTRT:
          output_asm_insn ("# ignored undefined behaviour logical right shift "
                           "of %1 by %2", operands);
          break;
        default:
          gcc_unreachable ();
        }
      return 0;
    }

  if (code == ASHIFT)
    {
      if (!msp430x && mode == HImode)
        {
          if (return_length)
            length = 2 + (MEM_P (operands[0]) ? 2 : 0);
          else
            for (i = 0; i < amt; i++)
              output_asm_insn ("RLA.W\t%0", operands);
        }
      else if (mode == SImode)
        {
          if (return_length)
            length = 4 + (MEM_P (operands[0]) ? 4 : 0)
              + (4 * msp430x_insn_required (operands[0]));
          else
            for (i = 0; i < amt; i++)
              output_asm_insn ("RLA%X0.W\t%L0 { RLC%X0.W\t%H0", operands);
        }
      else
        /* Catch unhandled cases.  */
        gcc_unreachable ();
    }
  else if (code == ASHIFTRT)
    {
      if (!msp430x && mode == HImode)
        {
          if (return_length)
            length = 2 + (MEM_P (operands[0]) ? 2 : 0);
          else
            for (i = 0; i < amt; i++)
              output_asm_insn ("RRA.W\t%0", operands);
        }
      else if (mode == SImode)
        {
          if (return_length)
            length = 4 + (MEM_P (operands[0]) ? 4 : 0)
              + (4 * msp430x_insn_required (operands[0]));
          else
            for (i = 0; i < amt; i++)
              output_asm_insn ("RRA%X0.W\t%H0 { RRC%X0.W\t%L0", operands);
        }
      else
        gcc_unreachable ();
    }
  else if (code == LSHIFTRT)
    {
      if (!msp430x && mode == HImode)
        {
          if (return_length)
            length = 4 + (MEM_P (operands[0]) ? 2 : 0);
          else
            for (i = 0; i < amt; i++)
              output_asm_insn ("CLRC { RRC.W\t%0", operands);
        }
      else if (mode == SImode)
        {
          if (return_length)
            length = 6 + (MEM_P (operands[0]) ? 4 : 0)
              + (4 * msp430x_insn_required (operands[0]));
          else
            for (i = 0; i < amt; i++)
              output_asm_insn ("CLRC { RRC%X0.W\t%H0 { RRC%X0.W\t%L0",
                               operands);
        }
      /* FIXME: Why doesn't "RRUX.W\t%H0 { RRC%X0.W\t%L0" work for msp430x?
         It causes execution timeouts e.g. pr41963.c.  */
#if 0
      else if (msp430x && mode == SImode)
        {
          if (return_length)
            length = 2;
          else
            for (i = 0; i < amt; i++)
              output_asm_insn ("RRUX.W\t%H0 { RRC%X0.W\t%L0", operands);
        }
#endif
      else
        gcc_unreachable ();
    }
  return length * amt;
}

/* Called by cbranch<mode>4 to coerce operands into usable forms.  */
void
msp430_fixup_compare_operands (machine_mode my_mode, rtx * operands)
{
  /* constants we're looking for, not constants which are allowed.  */
  int const_op_idx = 1;

  if (msp430_reversible_cmp_operator (operands[0], VOIDmode))
    const_op_idx = 2;

  if (GET_CODE (operands[const_op_idx]) != REG
      && GET_CODE (operands[const_op_idx]) != MEM)
    operands[const_op_idx] = copy_to_mode_reg (my_mode, operands[const_op_idx]);
}

/* Simplify_gen_subreg() doesn't handle memory references the way we
   need it to below, so we use this function for when we must get a
   valid subreg in a "natural" state.  */
rtx
msp430_subreg (machine_mode mode, rtx r, machine_mode omode, int byte)
{
  rtx rv;
  gcc_assert (mode == HImode);

  if (GET_CODE (r) == SUBREG
      && SUBREG_BYTE (r) == 0)
    {
      rtx ireg = SUBREG_REG (r);
      machine_mode imode = GET_MODE (ireg);

      /* special case for (HI (SI (PSI ...), 0)) */
      if (imode == PSImode
          && mode == HImode
          && byte == 0)
        rv = gen_rtx_SUBREG (mode, ireg, byte);
      else
        rv = simplify_gen_subreg (mode, ireg, imode, byte);
    }
  else if (GET_CODE (r) == MEM)
    {
      /* When byte == 2, we can be certain that we were already called with an
         identical rtx with byte == 0.  So we don't need to do anything to
         get a 2 byte offset of a (mem (post_inc)) rtx, since the address has
         already been offset by the post_inc itself.  */
      if (GET_CODE (XEXP (r, 0)) == POST_INC && byte == 2)
        byte = 0;
      rv = adjust_address (r, mode, byte);
    }
  else if (GET_CODE (r) == SYMBOL_REF
           && (byte == 0 || byte == 2)
           && mode == HImode)
    {
      rv = gen_rtx_ZERO_EXTRACT (HImode, r, GEN_INT (16), GEN_INT (8*byte));
      rv = gen_rtx_CONST (HImode, r);
    }
  else
    rv = simplify_gen_subreg (mode, r, omode, byte);

  if (!rv)
    gcc_unreachable ();

  return rv;
}

int
msp430_split_addsi (rtx *operands)
{
  operands[3] = msp430_subreg (HImode, operands[0], SImode, 0);
  operands[4] = msp430_subreg (HImode, operands[1], SImode, 0);
  operands[5] = msp430_subreg (HImode, operands[2], SImode, 0);
  operands[6] = msp430_subreg (HImode, operands[0], SImode, 2);
  operands[7] = msp430_subreg (HImode, operands[1], SImode, 2);
  operands[8] = msp430_subreg (HImode, operands[2], SImode, 2);

  /* BZ 64160: Do not use this splitter when the dest partially overlaps the
     source.  */
  if (reg_overlap_mentioned_p (operands[3], operands[7])
      || reg_overlap_mentioned_p (operands[3], operands[8]))
    return 1;

  if (GET_CODE (operands[5]) == CONST_INT)
    operands[9] = GEN_INT (INTVAL (operands[5]) & 0xffff);
  /* Handle post_inc, for example:
     (set (reg:SI)
          (plus:SI (reg:SI)
                   (mem:SI (post_inc:PSI (reg:PSI))))).  */
  else if (MEM_P (operands[5]) && GET_CODE (XEXP (operands[5], 0)) == POST_INC)
    {
      /* Strip out the post_inc from (mem (post_inc (reg))).  */
      operands[9] = XEXP (XEXP (operands[5], 0), 0);
      operands[9] = gen_rtx_MEM (HImode, operands[9]);
      /* Then zero extend as normal.  */
      operands[9] = gen_rtx_ZERO_EXTEND (SImode, operands[9]);
    }
  else
    operands[9] = gen_rtx_ZERO_EXTEND (SImode, operands[5]);
  return 0;
}

/* Called by movsi_x to generate the HImode operands.  */
void
msp430_split_movsi (rtx *operands)
{
  rtx op00, op02, op10, op12;

  op00 = msp430_subreg (HImode, operands[0], SImode, 0);
  op02 = msp430_subreg (HImode, operands[0], SImode, 2);

  if (GET_CODE (operands[1]) == CONST
      || GET_CODE (operands[1]) == SYMBOL_REF)
    {
      op10 = gen_rtx_ZERO_EXTRACT (HImode, operands[1], GEN_INT (16),
                                   GEN_INT (0));
      op10 = gen_rtx_CONST (HImode, op10);
      op12 = gen_rtx_ZERO_EXTRACT (HImode, operands[1], GEN_INT (16),
                                   GEN_INT (16));
      op12 = gen_rtx_CONST (HImode, op12);
    }
  else
    {
      op10 = msp430_subreg (HImode, operands[1], SImode, 0);
      op12 = msp430_subreg (HImode, operands[1], SImode, 2);
    }

  if (rtx_equal_p (operands[0], operands[1]))
    {
      operands[2] = op02;
      operands[4] = op12;
      operands[3] = op00;
      operands[5] = op10;
    }
  else if (rtx_equal_p (op00, op12)
           /* Catch the case where we are loading (rN, rN+1) from mem (rN).  */
           || (REG_P (op00) && reg_mentioned_p (op00, op10))
           /* Or storing (rN) into mem (rN).  */
           || (REG_P (op10) && reg_mentioned_p (op10, op00)))
    {
      operands[2] = op02;
      operands[4] = op12;
      operands[3] = op00;
      operands[5] = op10;
    }
  else
    {
      operands[2] = op00;
      operands[4] = op10;
      operands[3] = op02;
      operands[5] = op12;
    }
}

\f
/* The MSPABI specifies the names of various helper functions, many of
   which are compatible with GCC's helpers.  This table maps the GCC
   name to the MSPABI name.  */
static const struct
{
  char const * const gcc_name;
  char const * const ti_name;
}
helper_function_name_mappings[] =
  {
    /* Floating point to/from integer conversions.  */
    { "__truncdfsf2", "__mspabi_cvtdf" },
    { "__extendsfdf2", "__mspabi_cvtfd" },
    { "__fixdfhi", "__mspabi_fixdi" },
    { "__fixdfsi", "__mspabi_fixdli" },
    { "__fixdfdi", "__mspabi_fixdlli" },
    { "__fixunsdfhi", "__mspabi_fixdu" },
    { "__fixunsdfsi", "__mspabi_fixdul" },
    { "__fixunsdfdi", "__mspabi_fixdull" },
    { "__fixsfhi", "__mspabi_fixfi" },
    { "__fixsfsi", "__mspabi_fixfli" },
    { "__fixsfdi", "__mspabi_fixflli" },
    { "__fixunsfhi", "__mspabi_fixfu" },
    { "__fixunsfsi", "__mspabi_fixful" },
    { "__fixunsfdi", "__mspabi_fixfull" },
    { "__floathisf", "__mspabi_fltif" },
    { "__floatsisf", "__mspabi_fltlif" },
    { "__floatdisf", "__mspabi_fltllif" },
    { "__floathidf", "__mspabi_fltid" },
    { "__floatsidf", "__mspabi_fltlid" },
    { "__floatdidf", "__mspabi_fltllid" },
    { "__floatunhisf", "__mspabi_fltuf" },
    { "__floatunsisf", "__mspabi_fltulf" },
    { "__floatundisf", "__mspabi_fltullf" },
    { "__floatunhidf", "__mspabi_fltud" },
    { "__floatunsidf", "__mspabi_fltuld" },
    { "__floatundidf", "__mspabi_fltulld" },

    /* Floating point comparisons.  */
    /* GCC uses individual functions for each comparison, TI uses one
       compare <=> function.  */

    /* Floating point arithmetic.  */
    { "__adddf3", "__mspabi_addd" },
    { "__addsf3", "__mspabi_addf" },
    { "__divdf3", "__mspabi_divd" },
    { "__divsf3", "__mspabi_divf" },
    { "__muldf3", "__mspabi_mpyd" },
    { "__mulsf3", "__mspabi_mpyf" },
    { "__subdf3", "__mspabi_subd" },
    { "__subsf3", "__mspabi_subf" },
    /* GCC does not use helper functions for negation.  */

    /* Integer multiply, divide, remainder.  */
    { "__mulhi3", "__mspabi_mpyi" },
    { "__mulsi3", "__mspabi_mpyl" },
    { "__muldi3", "__mspabi_mpyll" },
#if 0
    /* Clarify signed vs unsigned first.  */
    { "__mulhisi3", "__mspabi_mpysl" }, /* gcc doesn't use widening multiply
                                           (yet?) */
    { "__mulsidi3", "__mspabi_mpysll" }, /* gcc doesn't use widening multiply
                                            (yet?) */
#endif

    { "__divhi3", "__mspabi_divi" },
    { "__divsi3", "__mspabi_divli" },
    { "__divdi3", "__mspabi_divlli" },
    { "__udivhi3", "__mspabi_divu" },
    { "__udivsi3", "__mspabi_divul" },
    { "__udivdi3", "__mspabi_divull" },
    { "__modhi3", "__mspabi_remi" },
    { "__modsi3", "__mspabi_remli" },
    { "__moddi3", "__mspabi_remlli" },
    { "__umodhi3", "__mspabi_remu" },
    { "__umodsi3", "__mspabi_remul" },
    { "__umoddi3", "__mspabi_remull" },

    /* Bitwise operations.  */
    /* Rotation - no rotation support yet.  */
    /* Logical left shift - gcc already does these itself.  */
    /* Arithmetic left shift - gcc already does these itself.  */
    /* Arithmetic right shift - gcc already does these itself.  */

    { NULL, NULL }
  };

/* Returns true if the current MCU supports an F5xxx series
   hardware multiper.  */

bool
msp430_use_f5_series_hwmult (void)
{
  static const char * cached_match = NULL;
  static bool cached_result;

  if (msp430_hwmult_type == MSP430_HWMULT_F5SERIES)
    return true;

  if (target_mcu == NULL || msp430_hwmult_type != MSP430_HWMULT_AUTO)
    return false;

  if (target_mcu == cached_match)
    return cached_result;

  cached_match = target_mcu;

  if (strncasecmp (target_mcu, "msp430f5", 8) == 0)
    return cached_result = true;
  if (strncasecmp (target_mcu, "msp430fr5", 9) == 0)
    return cached_result = true;
  if (strncasecmp (target_mcu, "msp430f6", 8) == 0)
    return cached_result = true;

  msp430_extract_mcu_data (target_mcu);

  if (extracted_mcu_data.name != NULL)
    return cached_result = extracted_mcu_data.hwmpy == 8;

  return cached_result = false;
}

/* Returns true if the current MCU has a second generation
   32-bit hardware multiplier.  */

static bool
msp430_use_32bit_hwmult (void)
{
  static const char * cached_match = NULL;
  static bool cached_result;

  if (msp430_hwmult_type == MSP430_HWMULT_LARGE)
    return true;

  if (target_mcu == NULL || msp430_hwmult_type != MSP430_HWMULT_AUTO)
    return false;

  if (target_mcu == cached_match)
    return cached_result;

  cached_match = target_mcu;

  msp430_extract_mcu_data (target_mcu);
  if (extracted_mcu_data.name != NULL)
    return cached_result = extracted_mcu_data.hwmpy == 4;

  return cached_result = false;
}

/* Returns true if the current MCU has a first generation
   16-bit hardware multiplier.  */

static bool
msp430_use_16bit_hwmult (void)
{
  static const char * cached_match = NULL;
  static bool         cached_result;

  if (msp430_hwmult_type == MSP430_HWMULT_SMALL)
    return true;

  if (target_mcu == NULL || msp430_hwmult_type != MSP430_HWMULT_AUTO)
    return false;

  if (target_mcu == cached_match)
    return cached_result;

  cached_match = target_mcu;

  msp430_extract_mcu_data (target_mcu);
  if (extracted_mcu_data.name != NULL)
    return cached_result = (extracted_mcu_data.hwmpy == 1
                            || extracted_mcu_data.hwmpy == 2);

  return cached_result = false;
}

/* Returns true if the current MCU does not have a
   hardware multiplier of any kind.  */

bool
msp430_has_hwmult (void)
{
  static const char * cached_match = NULL;
  static bool cached_result;

  if (msp430_hwmult_type == MSP430_HWMULT_NONE)
    return false;

  /* TRUE for any other explicit hwmult specified.  */
  if (msp430_hwmult_type != MSP430_HWMULT_AUTO)
    return true;

  /* Now handle -mhwmult=auto.  */
  if (target_mcu == NULL)
    return false;

  if (target_mcu == cached_match)
    return cached_result;

  cached_match = target_mcu;

  msp430_extract_mcu_data (target_mcu);
  if (extracted_mcu_data.name != NULL)
    return cached_result = extracted_mcu_data.hwmpy != 0;

  /* If we do not recognise the MCU name, we assume that it does not support
     any kind of hardware multiply - this is the safest assumption to make.  */
  return cached_result = false;
}

/* This function does the same as the default, but it will replace GCC
   function names with the MSPABI-specified ones.  */

void
msp430_output_labelref (FILE *file, const char *name)
{
  int i;

  for (i = 0; helper_function_name_mappings[i].gcc_name; i++)
    if (strcmp (helper_function_name_mappings[i].gcc_name, name) == 0)
      {
        name = helper_function_name_mappings[i].ti_name;
        break;
      }

  if (user_label_prefix[0] != 0)
    fputs (user_label_prefix, file);

  fputs (name, file);
}

/* Common code for msp430_print_operand...  */

static void
msp430_print_operand_raw (FILE * file, rtx op)
{
  HOST_WIDE_INT i;

  switch (GET_CODE (op))
    {
    case REG:
      fprintf (file, "%s", reg_names[REGNO (op)]);
      break;

    case CONST_INT:
      i = INTVAL (op);
      if (TARGET_ASM_HEX)
        fprintf (file, "%#" HOST_WIDE_INT_PRINT "x", i);
      else
        fprintf (file, "%" HOST_WIDE_INT_PRINT "d", i);
      break;

    case CONST:
    case PLUS:
    case MINUS:
    case SYMBOL_REF:
    case LABEL_REF:
      output_addr_const (file, op);
      break;

    default:
      print_rtl (file, op);
      break;
    }
}

#undef  TARGET_ASM_ALIGNED_PSI_OP
#define TARGET_ASM_ALIGNED_PSI_OP "\t.long\t"
#undef  TARGET_ASM_UNALIGNED_PSI_OP
#define TARGET_ASM_UNALIGNED_PSI_OP TARGET_ASM_ALIGNED_PSI_OP

#undef  TARGET_PRINT_OPERAND_ADDRESS
#define TARGET_PRINT_OPERAND_ADDRESS    msp430_print_operand_addr

/* Output to stdio stream FILE the assembler syntax for an
   instruction operand that is a memory reference whose address
   is ADDR.  */

static void
msp430_print_operand_addr (FILE * file, machine_mode /*mode*/, rtx addr)
{
  switch (GET_CODE (addr))
    {
    case PLUS:
      msp430_print_operand_raw (file, XEXP (addr, 1));
      gcc_assert (REG_P (XEXP (addr, 0)));
      fprintf (file, "(%s)", reg_names[REGNO (XEXP (addr, 0))]);
      return;

    case REG:
      fprintf (file, "@");
      break;

    case POST_INC:
      fprintf (file, "@%s+", reg_names[REGNO (XEXP (addr, 0))]);
      return;

    case CONST:
    case CONST_INT:
    case SYMBOL_REF:
    case LABEL_REF:
      fprintf (file, "&");
      break;

    default:
      break;
    }

  msp430_print_operand_raw (file, addr);
}

/* We can only allow signed 15-bit indexes i.e. +/-32K.  */
static bool
msp430_check_index_not_high_mem (rtx op)
{
  if (CONST_INT_P (op)
      && IN_RANGE (INTVAL (op), HOST_WIDE_INT_M1U << 15, (1 << 15) - 1))
    return true;
  return false;
}

/* If this returns true, we don't need a 430X insn.  */
static bool
msp430_check_plus_not_high_mem (rtx op)
{
  if (GET_CODE (op) != PLUS)
    return false;
  rtx op0 = XEXP (op, 0);
  rtx op1 = XEXP (op, 1);
  if (SYMBOL_REF_P (op0)
      && (SYMBOL_REF_FLAGS (op0) & SYMBOL_FLAG_LOW_MEM)
      && msp430_check_index_not_high_mem (op1))
    return true;
  return false;
}

/* Determine whether an RTX is definitely not a MEM referencing an address in
   the upper memory region.  Returns true if we've decided the address will be
   in the lower memory region, or the RTX is not a MEM.  Returns false
   otherwise.
   The Ys constraint will catch (mem (plus (const/reg)) but we catch cases
   involving a symbol_ref here.  */
bool
msp430_op_not_in_high_mem (rtx op)
{
  rtx op0;

  if (!TARGET_LARGE || !MEM_P (op))
    return true;

  op0 = XEXP (op, 0);

  if (SYMBOL_REF_P (op0) && (SYMBOL_REF_FLAGS (op0) & SYMBOL_FLAG_LOW_MEM))
    /* msp430_encode_section_info decided this mem will be in lower
       memory.  */
    return true;

  /* Check possibilites for (mem (plus)).
     e.g. (mem (const (plus ((symbol_ref) (const_int))))) : &addr+2.  */
  if (msp430_check_plus_not_high_mem (op0)
      || ((GET_CODE (op0) == CONST)
          && msp430_check_plus_not_high_mem (XEXP (op0, 0))))
    return true;

  /* An absolute 16-bit address is allowed.  */
  if ((CONST_INT_P (op0) && (IN_RANGE (INTVAL (op0), 0, (1 << 16) - 1))))
    return true;

  /* Return false when undecided.  */
  return false;
}

/* Based on the operand OP, is a 430X insn required to handle it?
   There are only 3 conditions for which a 430X insn is required:
   - PSImode operand
   - memory reference to a symbol which could be in upper memory
     (so its address is > 0xFFFF)
   - absolute address which has VOIDmode, i.e. (mem:HI (const_int))
   Use a 430 insn if none of these conditions are true.  */
bool
msp430x_insn_required (rtx op)
{
  return (GET_MODE (op) == PSImode
          || !msp430_op_not_in_high_mem (op));
}

#undef  TARGET_PRINT_OPERAND
#define TARGET_PRINT_OPERAND            msp430_print_operand

/* A   Select low 16-bits of the constant/register/memory operand.
   B   Select high 16-bits of the constant/register/memory
       operand.
   C   Select bits 32-47 of the constant/register/memory operand.
   D   Select bits 48-63 of the constant/register/memory operand.
   H   Equivalent to @code{B} (for backwards compatibility).
   I   Print the inverse (logical @code{NOT}) of the constant
       value.
   J   Print an integer without a @code{#} prefix.
   L   Equivalent to @code{A} (for backwards compatibility).
   O   Offset of the current frame from the top of the stack.
   Q   Use the @code{A} instruction postfix.
   R   Inverse of condition code, for unsigned comparisons.
   W   Subtract 16 from the constant value.
   X   Use the @code{X} instruction postfix.
   Y   Subtract 4 from the constant value.
   Z   Subtract 1 from the constant value.
   b   Append @code{.B}, @code{.W} or @code{.A} to the
       instruction, depending on the mode.
   d   Offset 1 byte of a memory reference or constant value.
   e   Offset 3 bytes of a memory reference or constant value.
   f   Offset 5 bytes of a memory reference or constant value.
   g   Offset 7 bytes of a memory reference or constant value.
   p   Print the value of 2, raised to the power of the given
       constant.  Used to select the specified bit position.
   r   Inverse of condition code, for signed comparisons.
   x   Equivialent to @code{X}, but only for pointers.  */

static void
msp430_print_operand (FILE * file, rtx op, int letter)
{
  rtx addr;
  /* These are used by the 'A', 'B', 'C', 'D', 'd', 'e', 'f' and 'g' modifiers
     to describe how to process the operand to get the requested value.  */
  int mem_off = 0;
  int reg_off = 0;
  int const_shift = 0;

  /* We can't use c, n, a, or l.  */
  switch (letter)
    {
    case 'Z':
      gcc_assert (CONST_INT_P (op));
      /* Print the constant value, less one.  */
      fprintf (file, "#%ld", (long) (INTVAL (op) - 1));
      return;
    case 'Y':
      gcc_assert (CONST_INT_P (op));
      /* Print the constant value, less four.  */
      fprintf (file, "#%ld", (long) (INTVAL (op) - 4));
      return;
    case 'W':
      gcc_assert (CONST_INT_P (op));
      /* Print the constant value, less 16.  */
      fprintf (file, "#%ld", (long) (INTVAL (op) - 16));
      return;
    case 'I':
      if (GET_CODE (op) == CONST_INT)
        {
          /* Inverse of constants */
          int i = INTVAL (op);
          fprintf (file, "%d", ~i);
          return;
        }
      op = XEXP (op, 0);
      break;
    case 'r': /* Conditional jump where the condition is reversed.  */
      switch (GET_CODE (op))
        {
        case EQ: fprintf (file, "NE"); break;
        case NE: fprintf (file, "EQ"); break;
        case GEU: fprintf (file, "LO"); break;
        case LTU: fprintf (file, "HS"); break;
        case GE: fprintf (file, "L"); break;
        case LT: fprintf (file, "GE"); break;
          /* Assume these have reversed operands.  */
        case GTU: fprintf (file, "HS"); break;
        case LEU: fprintf (file, "LO"); break;
        case GT: fprintf (file, "GE"); break;
        case LE: fprintf (file, "L"); break;
        default:
          msp430_print_operand_raw (file, op);
          break;
        }
      return;
    case 'R': /* Conditional jump where the operands are reversed.  */
      switch (GET_CODE (op))
        {
        case GTU: fprintf (file, "LO"); break;
        case LEU: fprintf (file, "HS"); break;
        case GT: fprintf (file, "L"); break;
        case LE: fprintf (file, "GE"); break;
        default:
          msp430_print_operand_raw (file, op);
          break;
        }
      return;
    case 'p': /* Bit position.  0 == 0x01, 3 = 0x08 etc.  */
      gcc_assert (CONST_INT_P (op));
      fprintf (file, "#%d", 1 << INTVAL (op));
      return;
    case 'b':
      switch (GET_MODE (op))
        {
        case E_QImode: fprintf (file, ".B"); return;
        case E_HImode: fprintf (file, ".W"); return;
        case E_PSImode: fprintf (file, ".A"); return;
        case E_SImode: fprintf (file, ".A"); return;
        default:
          return;
        }
    case 'd': case 'e': case 'f': case 'g':
      if (REG_P (op))
        {
          output_operand_lossage ("%%d, %%e, %%f, %%g operand modifiers are "
                                  "for memory references or constant values "
                                  "only");
          return;
        }
      /* fallthru */
    case 'B': case 'H': /* high half */
    case 'C':
    case 'D':
      switch (letter)
        {
        case 'd':
          mem_off = 1;
          const_shift = 8;
          break;
        case 'B':
        case 'H':
          mem_off = 2;
          reg_off = 1;
          const_shift = 16;
          break;
        case 'e':
          mem_off = 3;
          const_shift = 24;
          break;
        case 'C':
          mem_off = 4;
          reg_off = 2;
          const_shift = 32;
          break;
        case 'f':
          mem_off = 5;
          const_shift = 40;
          break;
        case 'D':
          mem_off = 6;
          reg_off = 3;
          const_shift = 48;
          break;
        case 'g':
          mem_off = 7;
          const_shift = 56;
          break;
        default:
          gcc_unreachable ();
          break;
        }
      /* fallthru */
    case 'A': case 'L': /* Low half.  */
      switch (GET_CODE (op))
        {
        case MEM:
          /* We don't need to adjust the address for post_inc.  */
          op = adjust_address (op, Pmode,
                               (GET_CODE (XEXP (op, 0)) == POST_INC)
                               ? 0 : mem_off);
          break;
        case REG:
          op = gen_rtx_REG (Pmode, REGNO (op) + reg_off);
          break;
        case CONST_INT:
          op = GEN_INT (((long long) INTVAL (op) >> const_shift) & 0xffff);
          letter = 0;
          break;
        default:
          /* If you get here, figure out a test case :-) */
          gcc_unreachable ();
        }
      break;

    case 'X':
      /* This is used to turn, for example, an ADD opcode into an ADDX
         opcode when we're using 20-bit addresses.
         This can be used for insns which have only one operand which might be
         a mem.
         If an insn has two different operands which could be memory operands,
         then the "Yx" constraint must be used to determine if the X suffix is
         required by checking both operands.  */
      if (GET_MODE (op) == PSImode
          || !msp430_op_not_in_high_mem (op))
        fprintf (file, "X");
      return;

    case 'x':
      /* Similarly, but only for PSImodes.  BIC, and other insn patterns using
         the QHI mode iterator (which includes, QI, HI, and PSImode) use
         this.  */
      if (GET_MODE (op) == PSImode)
        fprintf (file, "X");
      return;

    case 'Q':
      /* Likewise, for BR -> BRA.  */
      if (TARGET_LARGE)
        fprintf (file, "A");
      return;

    case 'O':
      /* Computes the offset to the top of the stack for the current frame.
         This has to be done here rather than in, say, msp430_expand_builtin()
         because builtins are expanded before the frame layout is
         determined.  */
      fprintf (file, "%d",
               msp430_initial_elimination_offset (ARG_POINTER_REGNUM,
                                                  STACK_POINTER_REGNUM)
               - (TARGET_LARGE ? 4 : 2));
      return;

    case 'J':
      gcc_assert (GET_CODE (op) == CONST_INT);
    case 0:
      break;
    default:
      output_operand_lossage ("invalid operand prefix");
      return;
    }

  switch (GET_CODE (op))
    {
    case REG:
      msp430_print_operand_raw (file, op);
      break;

    case MEM:
      addr = XEXP (op, 0);
      msp430_print_operand_addr (file, GET_MODE (op), addr);
      break;

    case CONST:
      if (GET_CODE (XEXP (op, 0)) == ZERO_EXTRACT)
        {
          op = XEXP (op, 0);
          switch (INTVAL (XEXP (op, 2)))
            {
            case 0:
              fprintf (file, "#lo (");
              msp430_print_operand_raw (file, XEXP (op, 0));
              fprintf (file, ")");
              break;

            case 16:
              fprintf (file, "#hi (");
              msp430_print_operand_raw (file, XEXP (op, 0));
              fprintf (file, ")");
              break;

            default:
              output_operand_lossage ("invalid zero extract");
              break;
            }
          break;
        }
      /* Fall through.  */
    case CONST_INT:
    case SYMBOL_REF:
    case LABEL_REF:
      if (letter == 0)
        fprintf (file, "#");
      msp430_print_operand_raw (file, op);
      break;

    case EQ: fprintf (file, "EQ"); break;
    case NE: fprintf (file, "NE"); break;
    case GEU: fprintf (file, "HS"); break;
    case LTU: fprintf (file, "LO"); break;
    case GE: fprintf (file, "GE"); break;
    case LT: fprintf (file, "L"); break;

    default:
      print_rtl (file, op);
      break;
    }
}

\f
/* Frame stuff.  */

rtx
msp430_return_addr_rtx (int count)
{
  int ra_size;
  if (count)
    return NULL_RTX;

  ra_size = TARGET_LARGE ? 4 : 2;
  if (crtl->args.pretend_args_size)
    ra_size += 2;

  return gen_rtx_MEM (Pmode, gen_rtx_PLUS (Pmode, arg_pointer_rtx,
                                           GEN_INT (- ra_size)));
}

rtx
msp430_incoming_return_addr_rtx (void)
{
  return gen_rtx_MEM (Pmode, stack_pointer_rtx);
}

/* If the path to the MSP430-GCC support files has been found by examining
   an environment variable (see msp430_check_env_var_for_devices in
   msp430-devices.cc), or -mdevices-csv-loc=, register this path as an include
   directory so the user can #include msp430.h without needing to specify the
   path to the support files with -I.  */
void
msp430_register_pre_includes (const char *sysroot ATTRIBUTE_UNUSED,
                              const char *iprefix ATTRIBUTE_UNUSED,
                              int stdinc ATTRIBUTE_UNUSED)
{
  char *include_dir;
  if (msp430_devices_csv_loc)
    include_dir = xstrdup (msp430_devices_csv_loc);
  else if (msp430_check_env_var_for_devices (&include_dir))
    return;
  include_dir = msp430_dirname (include_dir);

  include_dir = update_path (include_dir, "");
  add_path (include_dir, INC_SYSTEM, false, false);
}
\f
/* Instruction generation stuff.  */

/* Generate a sequence of instructions to sign-extend an HI
   value into an SI value.  Handles the tricky case where
   we are overwriting the destination.
   Return the number of bytes used by the emitted instructions.
   If RETURN_LENGTH is true then do not emit the assembly instruction
   sequence.  */
int
msp430x_extendhisi (rtx * operands, bool return_length)
{
  if (REGNO (operands[0]) == REGNO (operands[1]))
    {
      /* Low word of dest == source word.  */
      if (!return_length)
        output_asm_insn ("BIT.W\t#0x8000, %L0 { SUBC.W\t%H0, %H0 { INV.W\t%H0, %H0",
                         operands);
      return 8;
    }
  else if (! msp430x)
    {
      /* Note: This sequence is approximately the same length as invoking a
         helper function to perform the sign-extension, as in:

         MOV.W  %1, %L0
         MOV.W  %1, r12
         CALL   __mspabi_srai_15
         MOV.W  r12, %H0

         but this version does not involve any function calls or using argument
         registers, so it reduces register pressure.  */
      if (!return_length)
        output_asm_insn ("MOV.W\t%1, %L0 { BIT.W\t#0x8000, %L0 { SUBC.W\t%H0, %H0 { INV.W\t%H0, %H0",
                         operands);
      return 10;
    }
  else if (REGNO (operands[0]) + 1 == REGNO (operands[1]))
    {
      /* High word of dest == source word.  */
      if (!return_length)
        output_asm_insn ("MOV.W\t%1, %L0 { RPT\t#15 { RRAX.W\t%H0",
                         operands);
      return 6;
    }

  /* No overlap between dest and source.  */
  if (!return_length)
    output_asm_insn ("MOV.W\t%1, %L0 { MOV.W\t%1, %H0 { RPT\t#15 { RRAX.W\t%H0",
                     operands);
  return 8;
}

/* Stop GCC from thinking that it can eliminate (SUBREG:PSI (SI)).  */

#undef TARGET_CAN_CHANGE_MODE_CLASS
#define TARGET_CAN_CHANGE_MODE_CLASS msp430_can_change_mode_class

static bool
msp430_can_change_mode_class (machine_mode from, machine_mode to, reg_class_t)
{
  if ((to == PSImode && from == SImode)
      || (to == SImode && from == PSImode)
      || (to == DImode && from == PSImode)
      || (to == PSImode && from == DImode))
    return false;
  return true;
}
\f
#undef  TARGET_HAVE_SPECULATION_SAFE_VALUE
#define TARGET_HAVE_SPECULATION_SAFE_VALUE speculation_safe_value_not_needed

struct gcc_target targetm = TARGET_INITIALIZER;

#include "gt-msp430.h"