Subversion Repositories openrisc

/* Definitions of Tensilica's Xtensa target machine for GNU compiler.

   Copyright 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009

   Free Software Foundation, Inc.

   Contributed by Bob Wilson (bwilson@tensilica.com) at Tensilica.

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/>.  */

/* Get Xtensa configuration settings */

#include "xtensa-config.h"

/* Standard GCC variables that we reference.  */

extern int optimize;

/* External variables defined in xtensa.c.  */

extern unsigned xtensa_current_frame_size;

/* Macros used in the machine description to select various Xtensa

   configuration options.  */

#ifndef XCHAL_HAVE_MUL32_HIGH

#define XCHAL_HAVE_MUL32_HIGH 0

#endif

#ifndef XCHAL_HAVE_RELEASE_SYNC

#define XCHAL_HAVE_RELEASE_SYNC 0

#endif

#ifndef XCHAL_HAVE_S32C1I

#define XCHAL_HAVE_S32C1I 0

#endif

#ifndef XCHAL_HAVE_THREADPTR

#define XCHAL_HAVE_THREADPTR 0

#endif

#define TARGET_BIG_ENDIAN       XCHAL_HAVE_BE

#define TARGET_DENSITY          XCHAL_HAVE_DENSITY

#define TARGET_MAC16            XCHAL_HAVE_MAC16

#define TARGET_MUL16            XCHAL_HAVE_MUL16

#define TARGET_MUL32            XCHAL_HAVE_MUL32

#define TARGET_MUL32_HIGH       XCHAL_HAVE_MUL32_HIGH

#define TARGET_DIV32            XCHAL_HAVE_DIV32

#define TARGET_NSA              XCHAL_HAVE_NSA

#define TARGET_MINMAX           XCHAL_HAVE_MINMAX

#define TARGET_SEXT             XCHAL_HAVE_SEXT

#define TARGET_BOOLEANS         XCHAL_HAVE_BOOLEANS

#define TARGET_HARD_FLOAT       XCHAL_HAVE_FP

#define TARGET_HARD_FLOAT_DIV   XCHAL_HAVE_FP_DIV

#define TARGET_HARD_FLOAT_RECIP XCHAL_HAVE_FP_RECIP

#define TARGET_HARD_FLOAT_SQRT  XCHAL_HAVE_FP_SQRT

#define TARGET_HARD_FLOAT_RSQRT XCHAL_HAVE_FP_RSQRT

#define TARGET_ABS              XCHAL_HAVE_ABS

#define TARGET_ADDX             XCHAL_HAVE_ADDX

#define TARGET_RELEASE_SYNC     XCHAL_HAVE_RELEASE_SYNC

#define TARGET_S32C1I           XCHAL_HAVE_S32C1I

#define TARGET_ABSOLUTE_LITERALS XSHAL_USE_ABSOLUTE_LITERALS

#define TARGET_THREADPTR        XCHAL_HAVE_THREADPTR

#define TARGET_DEFAULT \

  ((XCHAL_HAVE_L32R     ? 0 : MASK_CONST16) |                            \

   MASK_SERIALIZE_VOLATILE)

#ifndef HAVE_AS_TLS

#define HAVE_AS_TLS 0

#endif

#define OVERRIDE_OPTIONS override_options ()

/* Reordering blocks for Xtensa is not a good idea unless the compiler

   understands the range of conditional branches.  Currently all branch

   relaxation for Xtensa is handled in the assembler, so GCC cannot do a

   good job of reordering blocks.  Do not enable reordering unless it is

   explicitly requested.  */

#define OPTIMIZATION_OPTIONS(LEVEL, SIZE)                               \

  do                                                                    \

    {                                                                   \

      flag_reorder_blocks = 0;                                           \

    }                                                                   \

  while (0)

/* Target CPU builtins.  */

#define TARGET_CPU_CPP_BUILTINS()                                       \

  do {                                                                  \

    builtin_assert ("cpu=xtensa");                                      \

    builtin_assert ("machine=xtensa");                                  \

    builtin_define ("__xtensa__");                                      \

    builtin_define ("__XTENSA__");                                      \

    builtin_define ("__XTENSA_WINDOWED_ABI__");                         \

    builtin_define (TARGET_BIG_ENDIAN ? "__XTENSA_EB__" : "__XTENSA_EL__"); \

    if (!TARGET_HARD_FLOAT)                                             \

      builtin_define ("__XTENSA_SOFT_FLOAT__");                         \

  } while (0)

#define CPP_SPEC " %(subtarget_cpp_spec) "

#ifndef SUBTARGET_CPP_SPEC

#define SUBTARGET_CPP_SPEC ""

#endif

#define EXTRA_SPECS                                                     \

  { "subtarget_cpp_spec", SUBTARGET_CPP_SPEC },

#ifdef __XTENSA_EB__

#define LIBGCC2_WORDS_BIG_ENDIAN 1

#else

#define LIBGCC2_WORDS_BIG_ENDIAN 0

#endif

/* Show we can debug even without a frame pointer.  */

#define CAN_DEBUG_WITHOUT_FP

/* Target machine storage layout */

/* Define this if most significant bit is lowest numbered

   in instructions that operate on numbered bit-fields.  */

#define BITS_BIG_ENDIAN (TARGET_BIG_ENDIAN != 0)

/* Define this if most significant byte of a word is the lowest numbered.  */

#define BYTES_BIG_ENDIAN (TARGET_BIG_ENDIAN != 0)

/* Define this if most significant word of a multiword number is the lowest.  */

#define WORDS_BIG_ENDIAN (TARGET_BIG_ENDIAN != 0)

#define MAX_BITS_PER_WORD 32

/* Width of a word, in units (bytes).  */

#define UNITS_PER_WORD 4

#define MIN_UNITS_PER_WORD 4

/* Width of a floating point register.  */

#define UNITS_PER_FPREG 4

/* Size in bits of various types on the target machine.  */

#define INT_TYPE_SIZE 32

#define SHORT_TYPE_SIZE 16

#define LONG_TYPE_SIZE 32

#define LONG_LONG_TYPE_SIZE 64

#define FLOAT_TYPE_SIZE 32

#define DOUBLE_TYPE_SIZE 64

#define LONG_DOUBLE_TYPE_SIZE 64

/* Allocation boundary (in *bits*) for storing pointers in memory.  */

#define POINTER_BOUNDARY 32

/* Allocation boundary (in *bits*) for storing arguments in argument list.  */

#define PARM_BOUNDARY 32

/* Allocation boundary (in *bits*) for the code of a function.  */

#define FUNCTION_BOUNDARY 32

/* Alignment of field after 'int : 0' in a structure.  */

#define EMPTY_FIELD_BOUNDARY 32

/* Every structure's size must be a multiple of this.  */

#define STRUCTURE_SIZE_BOUNDARY 8

/* There is no point aligning anything to a rounder boundary than this.  */

#define BIGGEST_ALIGNMENT 128

/* Set this nonzero if move instructions will actually fail to work

   when given unaligned data.  */

#define STRICT_ALIGNMENT 1

/* Promote integer modes smaller than a word to SImode.  Set UNSIGNEDP

   for QImode, because there is no 8-bit load from memory with sign

   extension.  Otherwise, leave UNSIGNEDP alone, since Xtensa has 16-bit

   loads both with and without sign extension.  */

#define PROMOTE_MODE(MODE, UNSIGNEDP, TYPE)                             \

  do {                                                                  \

    if (GET_MODE_CLASS (MODE) == MODE_INT                               \

        && GET_MODE_SIZE (MODE) < UNITS_PER_WORD)                       \

      {                                                                 \

        if ((MODE) == QImode)                                           \

          (UNSIGNEDP) = 1;                                              \

        (MODE) = SImode;                                                \

      }                                                                 \

  } while (0)

/* Imitate the way many other C compilers handle alignment of

   bitfields and the structures that contain them.  */

#define PCC_BITFIELD_TYPE_MATTERS 1

/* Disable the use of word-sized or smaller complex modes for structures,

   and for function arguments in particular, where they cause problems with

   register a7.  The xtensa_copy_incoming_a7 function assumes that there is

   a single reference to an argument in a7, but with small complex modes the

   real and imaginary components may be extracted separately, leading to two

   uses of the register, only one of which would be replaced.  */

#define MEMBER_TYPE_FORCES_BLK(FIELD, MODE) \

  ((MODE) == CQImode || (MODE) == CHImode)

/* Align string constants and constructors to at least a word boundary.

   The typical use of this macro is to increase alignment for string

   constants to be word aligned so that 'strcpy' calls that copy

   constants can be done inline.  */

#define CONSTANT_ALIGNMENT(EXP, ALIGN)                                  \

  ((TREE_CODE (EXP) == STRING_CST || TREE_CODE (EXP) == CONSTRUCTOR)    \

   && (ALIGN) < BITS_PER_WORD                                           \

        ? BITS_PER_WORD                                                 \

        : (ALIGN))

/* Align arrays, unions and records to at least a word boundary.

   One use of this macro is to increase alignment of medium-size

   data to make it all fit in fewer cache lines.  Another is to

   cause character arrays to be word-aligned so that 'strcpy' calls

   that copy constants to character arrays can be done inline.  */

#undef DATA_ALIGNMENT

#define DATA_ALIGNMENT(TYPE, ALIGN)                                     \

  ((((ALIGN) < BITS_PER_WORD)                                           \

    && (TREE_CODE (TYPE) == ARRAY_TYPE                                  \

        || TREE_CODE (TYPE) == UNION_TYPE                               \

        || TREE_CODE (TYPE) == RECORD_TYPE)) ? BITS_PER_WORD : (ALIGN))

/* Operations between registers always perform the operation

   on the full register even if a narrower mode is specified.  */

#define WORD_REGISTER_OPERATIONS

/* Xtensa loads are zero-extended by default.  */

#define LOAD_EXTEND_OP(MODE) ZERO_EXTEND

/* Standard register usage.  */

/* Number of actual hardware registers.

   The hardware registers are assigned numbers for the compiler

   from 0 to just below FIRST_PSEUDO_REGISTER.

   All registers that the compiler knows about must be given numbers,

   even those that are not normally considered general registers.

   The fake frame pointer and argument pointer will never appear in

   the generated code, since they will always be eliminated and replaced

   by either the stack pointer or the hard frame pointer.

   16           FRAME_POINTER (fake = initial sp)

   17           ARG_POINTER (fake = initial sp + framesize)

   18           BR[0] for floating-point CC

   19 - 34      FR[0] - FR[15]

   35           MAC16 accumulator */

#define FIRST_PSEUDO_REGISTER 36

/* Return the stabs register number to use for REGNO.  */

#define DBX_REGISTER_NUMBER(REGNO) xtensa_dbx_register_number (REGNO)

/* 1 for registers that have pervasive standard uses

   and are not available for the register allocator.  */

#define FIXED_REGISTERS                                                 \

{                                                                       \

  1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,                     \

  1, 1, 0,                                                               \

  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,                       \

  0,                                                                     \

}

/* 1 for registers not available across function calls.

   These must include the FIXED_REGISTERS and also any

   registers that can be used without being saved.

   The latter must include the registers where values are returned

   and the register where structure-value addresses are passed.

   Aside from that, you can include as many other registers as you like.  */

#define CALL_USED_REGISTERS                                             \

{                                                                       \

  1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1,                     \

  1, 1, 1,                                                              \

  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,                       \

  1,                                                                    \

}

/* For non-leaf procedures on Xtensa processors, the allocation order

   is as specified below by REG_ALLOC_ORDER.  For leaf procedures, we

   want to use the lowest numbered registers first to minimize

   register window overflows.  However, local-alloc is not smart

   enough to consider conflicts with incoming arguments.  If an

   incoming argument in a2 is live throughout the function and

   local-alloc decides to use a2, then the incoming argument must

   either be spilled or copied to another register.  To get around

   this, we define ORDER_REGS_FOR_LOCAL_ALLOC to redefine

   reg_alloc_order for leaf functions such that lowest numbered

   registers are used first with the exception that the incoming

   argument registers are not used until after other register choices

   have been exhausted.  */

#define REG_ALLOC_ORDER \

{  8,  9, 10, 11, 12, 13, 14, 15,  7,  6,  5,  4,  3,  2, \

  18, \

  19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, \

   0,  1, 16, 17, \

  35, \

}

#define ORDER_REGS_FOR_LOCAL_ALLOC order_regs_for_local_alloc ()

/* For Xtensa, the only point of this is to prevent GCC from otherwise

   giving preference to call-used registers.  To minimize window

   overflows for the AR registers, we want to give preference to the

   lower-numbered AR registers.  For other register files, which are

   not windowed, we still prefer call-used registers, if there are any.  */

extern const char xtensa_leaf_regs[FIRST_PSEUDO_REGISTER];

#define LEAF_REGISTERS xtensa_leaf_regs

/* For Xtensa, no remapping is necessary, but this macro must be

   defined if LEAF_REGISTERS is defined.  */

#define LEAF_REG_REMAP(REGNO) (REGNO)

/* This must be declared if LEAF_REGISTERS is set.  */

extern int leaf_function;

/* Internal macros to classify a register number.  */

/* 16 address registers + fake registers */

#define GP_REG_FIRST 0

#define GP_REG_LAST  17

#define GP_REG_NUM   (GP_REG_LAST - GP_REG_FIRST + 1)

/* Coprocessor registers */

#define BR_REG_FIRST 18

#define BR_REG_LAST  18 

#define BR_REG_NUM   (BR_REG_LAST - BR_REG_FIRST + 1)

/* 16 floating-point registers */

#define FP_REG_FIRST 19

#define FP_REG_LAST  34

#define FP_REG_NUM   (FP_REG_LAST - FP_REG_FIRST + 1)

/* MAC16 accumulator */

#define ACC_REG_FIRST 35

#define ACC_REG_LAST 35

#define ACC_REG_NUM  (ACC_REG_LAST - ACC_REG_FIRST + 1)

#define GP_REG_P(REGNO) ((unsigned) ((REGNO) - GP_REG_FIRST) < GP_REG_NUM)

#define BR_REG_P(REGNO) ((unsigned) ((REGNO) - BR_REG_FIRST) < BR_REG_NUM)

#define FP_REG_P(REGNO) ((unsigned) ((REGNO) - FP_REG_FIRST) < FP_REG_NUM)

#define ACC_REG_P(REGNO) ((unsigned) ((REGNO) - ACC_REG_FIRST) < ACC_REG_NUM)

/* Return number of consecutive hard regs needed starting at reg REGNO

   to hold something of mode MODE.  */

#define HARD_REGNO_NREGS(REGNO, MODE)                                   \

  (FP_REG_P (REGNO) ?                                                   \

        ((GET_MODE_SIZE (MODE) + UNITS_PER_FPREG - 1) / UNITS_PER_FPREG) : \

        ((GET_MODE_SIZE (MODE) + UNITS_PER_WORD - 1) / UNITS_PER_WORD))

/* Value is 1 if hard register REGNO can hold a value of machine-mode

   MODE.  */

extern char xtensa_hard_regno_mode_ok[][FIRST_PSEUDO_REGISTER];

#define HARD_REGNO_MODE_OK(REGNO, MODE)                                 \

  xtensa_hard_regno_mode_ok[(int) (MODE)][(REGNO)]

/* Value is 1 if it is a good idea to tie two pseudo registers

   when one has mode MODE1 and one has mode MODE2.

   If HARD_REGNO_MODE_OK could produce different values for MODE1 and MODE2,

   for any hard reg, then this must be 0 for correct output.  */

#define MODES_TIEABLE_P(MODE1, MODE2)                                   \

  ((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))

/* Register to use for pushing function arguments.  */

#define STACK_POINTER_REGNUM (GP_REG_FIRST + 1)

/* Base register for access to local variables of the function.  */

#define HARD_FRAME_POINTER_REGNUM (GP_REG_FIRST + 7)

/* The register number of the frame pointer register, which is used to

   access automatic variables in the stack frame.  For Xtensa, this

   register never appears in the output.  It is always eliminated to

   either the stack pointer or the hard frame pointer.  */

#define FRAME_POINTER_REGNUM (GP_REG_FIRST + 16)

/* Base register for access to arguments of the function.  */

#define ARG_POINTER_REGNUM (GP_REG_FIRST + 17)

/* For now we don't try to use the full set of boolean registers.  Without

   software pipelining of FP operations, there's not much to gain and it's

   a real pain to get them reloaded.  */

#define FPCC_REGNUM (BR_REG_FIRST + 0)

/* It is as good or better to call a constant function address than to

   call an address kept in a register.  */

#define NO_FUNCTION_CSE 1

/* Xtensa processors have "register windows".  GCC does not currently

   take advantage of the possibility for variable-sized windows; instead,

   we use a fixed window size of 8.  */

#define INCOMING_REGNO(OUT)                                             \

  ((GP_REG_P (OUT) &&                                                   \

    ((unsigned) ((OUT) - GP_REG_FIRST) >= WINDOW_SIZE)) ?               \

   (OUT) - WINDOW_SIZE : (OUT))

#define OUTGOING_REGNO(IN)                                              \

  ((GP_REG_P (IN) &&                                                    \

    ((unsigned) ((IN) - GP_REG_FIRST) < WINDOW_SIZE)) ?                 \

   (IN) + WINDOW_SIZE : (IN))

/* Define the classes of registers for register constraints in the

   machine description.  */

enum reg_class

{

  NO_REGS,                      /* no registers in set */

  BR_REGS,                      /* coprocessor boolean registers */

  FP_REGS,                      /* floating point registers */

  ACC_REG,                      /* MAC16 accumulator */

  SP_REG,                       /* sp register (aka a1) */

  RL_REGS,                      /* preferred reload regs (not sp or fp) */

  GR_REGS,                      /* integer registers except sp */

  AR_REGS,                      /* all integer registers */

  ALL_REGS,                     /* all registers */

  LIM_REG_CLASSES               /* max value + 1 */

};

#define N_REG_CLASSES (int) LIM_REG_CLASSES

#define GENERAL_REGS AR_REGS

/* An initializer containing the names of the register classes as C

   string constants.  These names are used in writing some of the

   debugging dumps.  */

#define REG_CLASS_NAMES                                                 \

{                                                                       \

  "NO_REGS",                                                            \

  "BR_REGS",                                                            \

  "FP_REGS",                                                            \

  "ACC_REG",                                                            \

  "SP_REG",                                                             \

  "RL_REGS",                                                            \

  "GR_REGS",                                                            \

  "AR_REGS",                                                            \

  "ALL_REGS"                                                            \

}

/* Contents of the register classes.  The Nth integer specifies the

   contents of class N.  The way the integer MASK is interpreted is

   that register R is in the class if 'MASK & (1 << R)' is 1.  */

#define REG_CLASS_CONTENTS \

{ \

  { 0x00000000, 0x00000000 }, /* no registers */ \

  { 0x00040000, 0x00000000 }, /* coprocessor boolean registers */ \

  { 0xfff80000, 0x00000007 }, /* floating-point registers */ \

  { 0x00000000, 0x00000008 }, /* MAC16 accumulator */ \

  { 0x00000002, 0x00000000 }, /* stack pointer register */ \

  { 0x0000ff7d, 0x00000000 }, /* preferred reload registers */ \

  { 0x0000fffd, 0x00000000 }, /* general-purpose registers */ \

  { 0x0003ffff, 0x00000000 }, /* integer registers */ \

  { 0xffffffff, 0x0000000f }  /* all registers */ \

}

#define IRA_COVER_CLASSES                                               \

{                                                                       \

  BR_REGS, FP_REGS, ACC_REG, AR_REGS, LIM_REG_CLASSES                   \

}

/* A C expression whose value is a register class containing hard

   register REGNO.  In general there is more that one such class;

   choose a class which is "minimal", meaning that no smaller class

   also contains the register.  */

extern const enum reg_class xtensa_regno_to_class[FIRST_PSEUDO_REGISTER];

#define REGNO_REG_CLASS(REGNO) xtensa_regno_to_class[ (REGNO) ]

/* Use the Xtensa AR register file for base registers.

   No index registers.  */

#define BASE_REG_CLASS AR_REGS

#define INDEX_REG_CLASS NO_REGS

/* SMALL_REGISTER_CLASSES is required for Xtensa, because all of the

   16 AR registers may be explicitly used in the RTL, as either

   incoming or outgoing arguments.  */

#define SMALL_REGISTER_CLASSES 1

#define PREFERRED_RELOAD_CLASS(X, CLASS)                                \

  xtensa_preferred_reload_class (X, CLASS, 0)

#define PREFERRED_OUTPUT_RELOAD_CLASS(X, CLASS)                         \

  xtensa_preferred_reload_class (X, CLASS, 1)

/* Return the maximum number of consecutive registers

   needed to represent mode MODE in a register of class CLASS.  */

#define CLASS_UNITS(mode, size)                                         \

  ((GET_MODE_SIZE (mode) + (size) - 1) / (size))

#define CLASS_MAX_NREGS(CLASS, MODE)                                    \

  (CLASS_UNITS (MODE, UNITS_PER_WORD))

/* Stack layout; function entry, exit and calling.  */

#define STACK_GROWS_DOWNWARD

/* Offset within stack frame to start allocating local variables at.  */

#define STARTING_FRAME_OFFSET                                           \

  crtl->outgoing_args_size

/* The ARG_POINTER and FRAME_POINTER are not real Xtensa registers, so

   they are eliminated to either the stack pointer or hard frame pointer.  */

#define ELIMINABLE_REGS                                                 \

{{ ARG_POINTER_REGNUM,          STACK_POINTER_REGNUM},                  \

 { ARG_POINTER_REGNUM,          HARD_FRAME_POINTER_REGNUM},             \

 { FRAME_POINTER_REGNUM,        STACK_POINTER_REGNUM},                  \

 { FRAME_POINTER_REGNUM,        HARD_FRAME_POINTER_REGNUM}}

/* Specify the initial difference between the specified pair of registers.  */

#define INITIAL_ELIMINATION_OFFSET(FROM, TO, OFFSET)                    \

  do {                                                                  \

    compute_frame_size (get_frame_size ());                             \

    switch (FROM)                                                       \

      {                                                                 \

      case FRAME_POINTER_REGNUM:                                        \

        (OFFSET) = 0;                                                    \

        break;                                                          \

      case ARG_POINTER_REGNUM:                                          \

        (OFFSET) = xtensa_current_frame_size;                           \

        break;                                                          \

      default:                                                          \

        gcc_unreachable ();                                             \

      }                                                                 \

  } while (0)

/* If defined, the maximum amount of space required for outgoing

   arguments will be computed and placed into the variable

   'crtl->outgoing_args_size'.  No space will be pushed

   onto the stack for each call; instead, the function prologue

   should increase the stack frame size by this amount.  */

#define ACCUMULATE_OUTGOING_ARGS 1

/* Offset from the argument pointer register to the first argument's

   address.  On some machines it may depend on the data type of the

   function.  If 'ARGS_GROW_DOWNWARD', this is the offset to the

   location above the first argument's address.  */

#define FIRST_PARM_OFFSET(FNDECL) 0

/* Align stack frames on 128 bits for Xtensa.  This is necessary for

   128-bit datatypes defined in TIE (e.g., for Vectra).  */

#define STACK_BOUNDARY 128

/* Functions do not pop arguments off the stack.  */

#define RETURN_POPS_ARGS(FUNDECL, FUNTYPE, SIZE) 0

/* Use a fixed register window size of 8.  */

#define WINDOW_SIZE 8

/* Symbolic macros for the registers used to return integer, floating

   point, and values of coprocessor and user-defined modes.  */

#define GP_RETURN (GP_REG_FIRST + 2 + WINDOW_SIZE)

#define GP_OUTGOING_RETURN (GP_REG_FIRST + 2)

/* Symbolic macros for the first/last argument registers.  */

#define GP_ARG_FIRST (GP_REG_FIRST + 2)

#define GP_ARG_LAST  (GP_REG_FIRST + 7)

#define GP_OUTGOING_ARG_FIRST (GP_REG_FIRST + 2 + WINDOW_SIZE)

#define GP_OUTGOING_ARG_LAST  (GP_REG_FIRST + 7 + WINDOW_SIZE)

#define MAX_ARGS_IN_REGISTERS 6

/* Don't worry about compatibility with PCC.  */

#define DEFAULT_PCC_STRUCT_RETURN 0

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

   assuming the value has mode MODE.  Because we have defined

   TARGET_PROMOTE_FUNCTION_MODE to promote everything, we have to

   perform the same promotions as PROMOTE_MODE.  */

#define XTENSA_LIBCALL_VALUE(MODE, OUTGOINGP)                           \

  gen_rtx_REG ((GET_MODE_CLASS (MODE) == MODE_INT                       \

                && GET_MODE_SIZE (MODE) < UNITS_PER_WORD)               \

               ? SImode : (MODE),                                       \

               OUTGOINGP ? GP_OUTGOING_RETURN : GP_RETURN)

#define LIBCALL_VALUE(MODE)                                             \

  XTENSA_LIBCALL_VALUE ((MODE), 0)

#define LIBCALL_OUTGOING_VALUE(MODE)                                    \

  XTENSA_LIBCALL_VALUE ((MODE), 1)

/* A C expression that is nonzero if REGNO is the number of a hard

   register in which the values of called function may come back.  A

   register whose use for returning values is limited to serving as

   the second of a pair (for a value of type 'double', say) need not

   be recognized by this macro.  If the machine has register windows,

   so that the caller and the called function use different registers

   for the return value, this macro should recognize only the caller's

   register numbers.  */

#define FUNCTION_VALUE_REGNO_P(N)                                       \

  ((N) == GP_RETURN)

/* A C expression that is nonzero if REGNO is the number of a hard

   register in which function arguments are sometimes passed.  This

   does *not* include implicit arguments such as the static chain and

   the structure-value address.  On many machines, no registers can be

   used for this purpose since all function arguments are pushed on

   the stack.  */

#define FUNCTION_ARG_REGNO_P(N)                                         \

  ((N) >= GP_OUTGOING_ARG_FIRST && (N) <= GP_OUTGOING_ARG_LAST)

/* Record the number of argument words seen so far, along with a flag to

   indicate whether these are incoming arguments.  (FUNCTION_INCOMING_ARG

   is used for both incoming and outgoing args, so a separate flag is

   needed.  */

typedef struct xtensa_args

{

  int arg_words;

  int incoming;

} CUMULATIVE_ARGS;

#define INIT_CUMULATIVE_ARGS(CUM, FNTYPE, LIBNAME, INDIRECT, N_NAMED_ARGS) \

  init_cumulative_args (&CUM, 0)

#define INIT_CUMULATIVE_INCOMING_ARGS(CUM, FNTYPE, LIBNAME)             \

  init_cumulative_args (&CUM, 1)

/* Update the data in CUM to advance over an argument

   of mode MODE and data type TYPE.

   (TYPE is null for libcalls where that information may not be available.)  */

#define FUNCTION_ARG_ADVANCE(CUM, MODE, TYPE, NAMED)                    \

  function_arg_advance (&CUM, MODE, TYPE)

#define FUNCTION_ARG(CUM, MODE, TYPE, NAMED) \

  function_arg (&CUM, MODE, TYPE, FALSE)

#define FUNCTION_INCOMING_ARG(CUM, MODE, TYPE, NAMED) \

  function_arg (&CUM, MODE, TYPE, TRUE)

#define FUNCTION_ARG_BOUNDARY function_arg_boundary

/* Profiling Xtensa code is typically done with the built-in profiling

   feature of Tensilica's instruction set simulator, which does not

   require any compiler support.  Profiling code on a real (i.e.,

   non-simulated) Xtensa processor is currently only supported by

   GNU/Linux with glibc.  The glibc version of _mcount doesn't require

   counter variables.  The _mcount function needs the current PC and

   the current return address to identify an arc in the call graph.

   Pass the current return address as the first argument; the current

   PC is available as a0 in _mcount's register window.  Both of these

   values contain window size information in the two most significant

   bits; we assume that _mcount will mask off those bits.  The call to

   _mcount uses a window size of 8 to make sure that it doesn't clobber

   any incoming argument values.  */

#define NO_PROFILE_COUNTERS     1

#define FUNCTION_PROFILER(FILE, LABELNO) \

  do {                                                                  \

    fprintf (FILE, "\t%s\ta10, a0\n", TARGET_DENSITY ? "mov.n" : "mov"); \

    if (flag_pic)                                                       \

      {                                                                 \

        fprintf (FILE, "\tmovi\ta8, _mcount@PLT\n");                    \

        fprintf (FILE, "\tcallx8\ta8\n");                               \

      }                                                                 \

    else                                                                \

      fprintf (FILE, "\tcall8\t_mcount\n");                             \

  } while (0)

/* Stack pointer value doesn't matter at exit.  */

#define EXIT_IGNORE_STACK 1

/* Size in bytes of the trampoline, as an integer.  Make sure this is

   a multiple of TRAMPOLINE_ALIGNMENT to avoid -Wpadded warnings.  */

#define TRAMPOLINE_SIZE (TARGET_CONST16 || TARGET_ABSOLUTE_LITERALS ? 60 : 52)

/* Alignment required for trampolines, in bits.  */

#define TRAMPOLINE_ALIGNMENT 32

/* If defined, a C expression that produces the machine-specific code

   to setup the stack so that arbitrary frames can be accessed.

   On Xtensa, a stack back-trace must always begin from the stack pointer,

   so that the register overflow save area can be located.  However, the

   stack-walking code in GCC always begins from the hard_frame_pointer

   register, not the stack pointer.  The frame pointer is usually equal

   to the stack pointer, but the __builtin_return_address and

   __builtin_frame_address functions will not work if count > 0 and

   they are called from a routine that uses alloca.  These functions

   are not guaranteed to work at all if count > 0 so maybe that is OK.

   A nicer solution would be to allow the architecture-specific files to

   specify whether to start from the stack pointer or frame pointer.  That

   would also allow us to skip the machine->accesses_prev_frame stuff that

   we currently need to ensure that there is a frame pointer when these

   builtin functions are used.  */

#define SETUP_FRAME_ADDRESSES  xtensa_setup_frame_addresses

/* A C expression whose value is RTL representing the address in a

   stack frame where the pointer to the caller's frame is stored.

   Assume that FRAMEADDR is an RTL expression for the address of the

   stack frame itself.

   For Xtensa, there is no easy way to get the frame pointer if it is

   not equivalent to the stack pointer.  Moreover, the result of this

   macro is used for continuing to walk back up the stack, so it must

   return the stack pointer address.  Thus, there is some inconsistency

   here in that __builtin_frame_address will return the frame pointer

   when count == 0 and the stack pointer when count > 0.  */

#define DYNAMIC_CHAIN_ADDRESS(frame)                                    \

  gen_rtx_PLUS (Pmode, frame, GEN_INT (-3 * UNITS_PER_WORD))

/* Define this if the return address of a particular stack frame is

   accessed from the frame pointer of the previous stack frame.  */

#define RETURN_ADDR_IN_PREVIOUS_FRAME

/* A C expression whose value is RTL representing the value of the

   return address for the frame COUNT steps up from the current

   frame, after the prologue.  */

#define RETURN_ADDR_RTX  xtensa_return_addr

/* Addressing modes, and classification of registers for them.  */

/* C expressions which are nonzero if register number NUM is suitable

   for use as a base or index register in operand addresses.  */

#define REGNO_OK_FOR_INDEX_P(NUM) 0

#define REGNO_OK_FOR_BASE_P(NUM) \

  (GP_REG_P (NUM) || GP_REG_P ((unsigned) reg_renumber[NUM]))

/* C expressions that are nonzero if X (assumed to be a `reg' RTX) is

   valid for use as a base or index register.  */

#ifdef REG_OK_STRICT

#define REG_OK_STRICT_FLAG 1

#else

#define REG_OK_STRICT_FLAG 0

#endif

#define BASE_REG_P(X, STRICT)                                           \

  ((!(STRICT) && REGNO (X) >= FIRST_PSEUDO_REGISTER)                    \

   || REGNO_OK_FOR_BASE_P (REGNO (X)))

#define REG_OK_FOR_INDEX_P(X) 0

#define REG_OK_FOR_BASE_P(X) BASE_REG_P (X, REG_OK_STRICT_FLAG)

/* Maximum number of registers that can appear in a valid memory address.  */

#define MAX_REGS_PER_ADDRESS 1

/* A C expression that is 1 if the RTX X is a constant which is a

   valid address.  This is defined to be the same as 'CONSTANT_P (X)',

   but rejecting CONST_DOUBLE.  */

#define CONSTANT_ADDRESS_P(X)                                           \

  ((GET_CODE (X) == LABEL_REF || GET_CODE (X) == SYMBOL_REF             \

    || GET_CODE (X) == CONST_INT || GET_CODE (X) == HIGH                \

    || (GET_CODE (X) == CONST)))

/* Nonzero if the constant value X is a legitimate general operand.

   It is given that X satisfies CONSTANT_P or is a CONST_DOUBLE.  */

#define LEGITIMATE_CONSTANT_P(X) (! xtensa_tls_referenced_p (X))

/* A C expression that is nonzero if X is a legitimate immediate

   operand on the target machine when generating position independent

   code.  */

#define LEGITIMATE_PIC_OPERAND_P(X)                                     \

  ((GET_CODE (X) != SYMBOL_REF                                          \

    || (SYMBOL_REF_LOCAL_P (X) && !SYMBOL_REF_EXTERNAL_P (X)))          \

   && GET_CODE (X) != LABEL_REF                                         \

   && GET_CODE (X) != CONST)