Subversion Repositories openrisc_2011-10-31

/* Definitions of target machine for GNU compiler.  OpenRISC 1000 version.

   Copyright (C) 1987, 1988, 1992, 1995, 1996, 1999, 2000, 2001, 2002,

   2003, 2004, 2005 Free Software Foundation, Inc.

   Copyright (C) 2010 Embecosm Limited

   Contributed by Damjan Lampret <damjanl@bsemi.com> in 1999.

   Major optimizations by Matjaz Breskvar <matjazb@bsemi.com> in 2005.

This file is part of GNU CC.

GNU CC 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 1, or (at your option)

any later version.

GNU CC 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 GNU CC; see the file COPYING.  If not, write to

the Free Software Foundation, 59 Temple Place - Suite 330,

Boston, MA 02111-1307, USA.  */

#ifndef _OR32_H_

#define _OR32_H_

/* Target CPU builtins */

#define TARGET_CPU_CPP_BUILTINS()               \

  do                                            \

    {                                           \

      builtin_define_std ("OR32");              \

      builtin_define_std ("or32");              \

      if (or32_libc == or32_libc_uclibc)        \

        builtin_define ("__UCLIBC__");          \

      builtin_assert ("cpu=or32");              \

      builtin_assert ("machine=or32");          \

    }                                           \

  while (0)

/* A string corresponding to the installation directory for target libraries

   and includes. Make it available to SPEC definitions via EXTRA_SPECS */

#define CONC_DIR(dir1, dir2) dir1 "/../../" dir2

#define TARGET_PREFIX CONC_DIR (STANDARD_EXEC_PREFIX, DEFAULT_TARGET_MACHINE)

#define EXTRA_SPECS                                   \

  { "target_prefix", TARGET_PREFIX }

#undef CPP_SPEC

#define CPP_SPEC \

  "%{!mnewlib:%{pthread:-D_XOPEN_SOURCE=700}}"

/* Make sure we pick up the crti.o, crtbegin.o, crtend.o and crtn.o files. */

#undef STARTFILE_SPEC

#define STARTFILE_SPEC \

  "%{!shared:"\

    "%{mnewlib:%(target_prefix)/lib/crt0.o} "\

    "%{!mnewlib:crt0.o%s} crti.o%s crtbegin.o%s}"

#undef ENDFILE_SPEC

#define ENDFILE_SPEC "crtend.o%s crtn.o%s"

/* Specify the newlib library path if necessary */

#undef LINK_SPEC

#define LINK_SPEC "%{mnewlib:-L%(target_prefix)/newlib}"

/* Override previous definitions (linux.h). Newlib doesn't have a profiling

   version of the library, but it does have a debugging version (libg.a) */

#undef LIB_SPEC 

#define LIB_SPEC "%{!mnewlib:"                                           \

                   "%{pthread:"                                          \

                     "--whole-archive -lpthread --no-whole-archive} "    \

                   "%{!p:%{!pg:-lc}}%{p:-lc_p}%{pg:-lc_p}}               \

                  %{mnewlib:%{!g:-lc -lor32 -lboard -u free -lc}         \

                            %{g:-lg -lor32 -lboard -u free -lg}          \

                            %{mboard=*:-L%(target_prefix)/lib/boards/%*} \

                            %{!mboard=*:-L%(target_prefix)/lib/boards/or1ksim}}"

#define TARGET_VERSION fprintf (stderr, " (OpenRISC 1000) Mask 0x%x", MASK_HARD_MUL);

/* Run-time compilation parameters selecting different hardware subsets.  */

extern int target_flags;

/* Target machine storage layout */

/* Define this if most significant bit is lowest numbered

   in instructions that operate on numbered bit-fields.

   This is not true on the or32.  */

#define BITS_BIG_ENDIAN 0

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

#define BYTES_BIG_ENDIAN 1

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

#define WORDS_BIG_ENDIAN 1

/* Number of bits in an addressable storage unit */

#define BITS_PER_UNIT 8

#define BITS_PER_WORD 32

#define SHORT_TYPE_SIZE 16

#define INT_TYPE_SIZE 32

#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

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

#define UNITS_PER_WORD 4

/* Width in bits of a pointer.

   See also the macro `Pmode' defined below.  */

#define POINTER_SIZE 32

/* 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

/* Boundary (in *bits*) on which stack pointer should be aligned.  */

#define STACK_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 8

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

#define STRUCTURE_SIZE_BOUNDARY (TARGET_PADSTRUCT ? 32 : 8)

/* A bitfield declared as `int' forces `int' alignment for the struct.  */

#define PCC_BITFIELD_TYPE_MATTERS 1

/* No data type wants to be aligned rounder than this.  */

#define BIGGEST_ALIGNMENT 32

/* The best alignment to use in cases where we have a choice.  */

#define FASTEST_ALIGNMENT 32

#define ROUND_TYPE_ALIGN(STRUCT, COMPUTED, SPECIFIED)   \

  ((TREE_CODE (STRUCT) == RECORD_TYPE                   \

    || TREE_CODE (STRUCT) == UNION_TYPE                 \

    || TREE_CODE (STRUCT) == QUAL_UNION_TYPE)           \

   && !TYPE_PACKED (STRUCT)                             \

   && TYPE_FIELDS (STRUCT) != 0                         \

     ? MAX (MAX ((COMPUTED), (SPECIFIED)), or32_struct_alignment (STRUCT)) \

     : MAX ((COMPUTED), (SPECIFIED)))                   \

/* Make strings word-aligned so strcpy from constants will be faster.  */

/*

#define CONSTANT_ALIGNMENT(EXP, ALIGN)                                  \

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

    && (ALIGN) < FASTEST_ALIGNMENT                                      \

   ? FASTEST_ALIGNMENT : (ALIGN))

*/

/* 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.  */

/*

#define DATA_ALIGNMENT(TYPE, ALIGN)                                     \

  ((((ALIGN) < FASTEST_ALIGNMENT)                                       \

    && (TREE_CODE (TYPE) == ARRAY_TYPE                                  \

        || TREE_CODE (TYPE) == UNION_TYPE                               \

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

*/ /* CHECK - btw code gets bigger with this one */

#define DATA_ALIGNMENT(TYPE, ALIGN) \

  ((ALIGN) < FASTEST_ALIGNMENT \

   ? or32_data_alignment ((TYPE), (ALIGN)) : (ALIGN))

#define LOCAL_ALIGNMENT(TYPE, ALIGN) \

  ((ALIGN) < FASTEST_ALIGNMENT \

   ? or32_data_alignment ((TYPE), (ALIGN)) : (ALIGN))

/* Define this if move instructions will actually fail to work

   when given unaligned data.  */

#define STRICT_ALIGNMENT 1 /* CHECK */

/* Align an address */

#define OR32_ALIGN(n,a) (((n) + (a) - 1) & ~((a) - 1))

/* Define if operations between registers always perform the operation

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

#define WORD_REGISTER_OPERATIONS  /* CHECK */

/* Define if loading in MODE, an integral mode narrower than BITS_PER_WORD

   will either zero-extend or sign-extend.  The value of this macro should

   be the code that says which one of the two operations is implicitly

   done, NIL if none.  */

#define LOAD_EXTEND_OP(MODE) ZERO_EXTEND

/* Define this macro if it is advisable to hold scalars in registers

   in a wider mode than that declared by the program.  In such cases,

   the value is constrained to be within the bounds of the declared

   type, but kept valid in the wider mode.  The signedness of the

   extension may differ from that of the type. */

#define PROMOTE_MODE(MODE, UNSIGNEDP, TYPE)     \

  if (GET_MODE_CLASS (MODE) == MODE_INT         \

      && GET_MODE_SIZE (MODE) < UNITS_PER_WORD) \

    (MODE) = SImode;

  /* CHECK */

/*

 * brings 0.4% improvment in static size for linux

 *

#define PROMOTE_FOR_CALL_ONLY

*/

/* Define this macro if 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 /* check */

/* 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.  */

#define OR32_LAST_ACTUAL_REG       31

#define ARG_POINTER_REGNUM     (OR32_LAST_ACTUAL_REG + 1)

#define FRAME_POINTER_REGNUM   (ARG_POINTER_REGNUM + 1)

#define OR32_LAST_INT_REG      FRAME_POINTER_REGNUM

#define OR32_FLAGS_REG         (OR32_LAST_INT_REG + 1)

#define FIRST_PSEUDO_REGISTER  (OR32_FLAGS_REG + 1)

/* 1 for registers that have pervasive standard uses

   and are not available for the register allocator.

   On the or32, these are r1 as stack pointer and

   r2 as frame/arg pointer.  r9 is link register, r0

   is zero, r10 is linux thread */

#define FIXED_REGISTERS { \

  1, 1, 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, 0, 0, 0, 1, 1, 1 }

/* 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, 1, 1, 1, 1, 1, \

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

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

  0, 1, 0, 1, 0, 1, 0, 1, 1, 1, 1}

/* stack pointer: must be FIXED and CALL_USED */

/* hard frame pointer: must be call saved.  */

/* soft frame pointer / arg pointer: must be FIXED and CALL_USED */

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

   to hold something of mode MODE.

   This is ordinarily the length in words of a value of mode MODE

   but can be less for certain modes in special long registers.

   On the or32, all registers are one word long.  */

#define HARD_REGNO_NREGS(REGNO, MODE)   \

 ((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. */

#define HARD_REGNO_MODE_OK(REGNO, MODE) 1

/* 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)  1

/* A C expression for the cost of moving data of mode mode from a register in

   class "from" to one in class "to". The classes are expressed using the

   enumeration values such as GENERAL_REGS. A value of 2 is the default; other

   values are interpreted relative to that.

   It is not required that the cost always equal 2 when "from" is the same as

   "to"; on some machines it is expensive to move between registers if they are

   not general registers.

   If reload sees an insn consisting of a single set between two hard

   registers, and if REGISTER_MOVE_COST applied to their classes returns a

   value of 2, reload does not check to ensure that the constraints of the

   insn are met. Setting a cost of other than 2 will allow reload to verify

   that the constraints are met. You should do this if the "movm" pattern's

   constraints do not allow such copying.

   JPB 31-Aug-10: This is just the default. */

#define REGISTER_MOVE_COST(mode, from, to)  2

/* A C expression for the cost of moving data of mode mode between a register

   of class "class" and memory; "in" is zero if the value is to be written to

   memory, nonzero if it is to be read in. This cost is relative to those in

   REGISTER_MOVE_COST. If moving between registers and memory is more

   expensive than between two registers, you should define this macro to

   express the relative cost.

   If you do not define this macro, GCC uses a default cost of 4 plus the cost

   of copying via a secondary reload register, if one is needed. If your

   machine requires a secondary reload register to copy between memory and a

   register of class but the reload mechanism is more complex than copying via

   an intermediate, define this macro to reflect the actual cost of the move.

   GCC defines the function "memory_move_secondary_cost" if secondary reloads

   are needed. It computes the costs due to copying via a secondary

   register. If your machine copies from memory using a secondary register in

   the conventional way but the default base value of 4 is not correct for

   your machine, define this macro to add some other value to the result of

   that function. The arguments to that function are the same as to this

   macro.

   JPB 31-Aug-10. Is this really correct? I suppose the OR32 only takes one

                  cycle, notionally, to access memory, but surely that will

                  often stall the  pipeline. Needs more investigation. */

#define MEMORY_MOVE_COST(mode, class, in)  2

/* A C expression for the cost of a branch instruction. A value of 1 is the

   default; other values are interpreted relative to that. Parameter "speed_p"

   is TRUE when the branch in question should be optimized for speed. When it

   is FALSE, BRANCH_COST should be returning value optimal for code size

   rather then performance considerations. "predictable_p" is true for well

   predictable branches. On many architectures the BRANCH_COST can be reduced

   then.

   JPB 31-Aug-10. The original code had the comment that "... this should

                  specify the cost of a branch insn; roughly the number of

                  extra insns that should be added to avoid a branch.

                  Set this to 3 on the or32 since that is roughly the average

                  cost of an unscheduled conditional branch.

                  Cost of 2 and 3 give equal and ~0.7% bigger binaries

                  respectively."

                  This seems ad-hoc. Probably we need some experiments. */

#define BRANCH_COST(speed_p, predictable_p)  2

/* Specify the registers used for certain standard purposes.

   The values of these macros are register numbers.  */

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

#define STACK_POINTER_REGNUM 1

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

#define HARD_FRAME_POINTER_REGNUM 2

/* Link register. */

#define LINK_REGNUM 9

/* Define this macro if debugging can be performed even without a frame pointer.

   If this macro is de ned, GCC will turn on the `-fomit-frame-pointer' option

   whenever `-O' is specifed.

   This should work for the OpenRISC architecture. Particularly if we

   generate DWARF2 output OK. */

#define CAN_DEBUG_WITHOUT_FP 

/* This function computes the initial size of the frame (difference between SP

   and FP) after the function prologue. */

#define INITIAL_FRAME_POINTER_OFFSET(depth)                             \

  {                                                                     \

    int regno;                                                          \

    int offset = 0;                                                      \

                                                                        \

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

      {                                                                 \

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

          {                                                             \

            offset += 4;                                                \

          }                                                             \

      }                                                                 \

                                                                        \

    (depth) = ((!current_function_is_leaf                               \

                || df_regs_ever_live_p (LINK_REGNUM)) ? 4 : 0)           \

      + (frame_pointer_needed ? 4 : 0)                                   \

      + offset                                                          \

      + OR32_ALIGN (crtl->outgoing_args_size, 4)                        \

      + OR32_ALIGN (get_frame_size(), 4);                               \

  }

/* Register in which static-chain is passed to a function.  */

#define STATIC_CHAIN_REGNUM 11

#define PROLOGUE_TMP 13

#define EPILOGUE_TMP 3

/* Register in which address to store a structure value

   is passed to a function.  */

/*#define STRUCT_VALUE_REGNUM 0*/

/* Pass address of result struct to callee as "invisible" first argument */

#define STRUCT_VALUE 0

/* -----------------------[ PHX start ]-------------------------------- */

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

   machine description.  Also define ranges of constants.

   One of the classes must always be named ALL_REGS and include all hard regs.

   If there is more than one class, another class must be named NO_REGS

   and contain no registers.

   The name GENERAL_REGS must be the name of a class (or an alias for

   another name such as ALL_REGS).  This is the class of registers

   that is allowed by "g" or "r" in a register constraint.

   Also, registers outside this class are allocated only when

   instructions express preferences for them.

   GENERAL_REGS and BASE_REGS classess are the same on or32.

   The classes must be numbered in nondecreasing order; that is,

   a larger-numbered class must never be contained completely

   in a smaller-numbered class.

   For any two classes, it is very desirable that there be another

   class that represents their union.  */

/* The or32 has only one kind of registers, so NO_REGS, GENERAL_REGS

   and ALL_REGS are the only classes.  */

/* JPB 26-Aug-10: Based on note from Mikhael (mirekez@gmail.com), we don't

   need CR_REGS and it is in the wrong place for later things! */

enum reg_class

{

  NO_REGS,

  GENERAL_REGS,

  ALL_REGS,

  LIM_REG_CLASSES

};

#define N_REG_CLASSES (int) LIM_REG_CLASSES

/* Give names of register classes as strings for dump file.   */

#define REG_CLASS_NAMES                                                 \

{                                                                       \

  "NO_REGS",                                                            \

  "GENERAL_REGS",                                                       \

  "ALL_REGS"                                                            \

}

/* Define which registers fit in which classes.  This is an initializer for a

   vector of HARD_REG_SET of length N_REG_CLASSES.

   An initializer containing the contents of the register classes, as integers

   which are bit masks.  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.

   When the machine has more than 32 registers, an integer does not suffice.

   Then the integers are replaced by sub-initializers, braced groupings

   containing several integers.  Each sub-initializer must be suitable as an

   initializer for the type `HARD_REG_SET' which is defined in

   `hard-reg-set.h'.

   For the OR32 we have the minimal set. GENERAL_REGS is all except r0, which

   it permanently zero. */

#define REG_CLASS_CONTENTS                                              \

  {                                                                     \

    { 0x00000000, 0x00000000 },         /* NO_REGS */                   \

    { 0xffffffff, 0x00000003 },         /* GENERAL_REGS */              \

    { 0xffffffff, 0x00000007 }          /* ALL_REGS */                  \

  }

/* The same information, inverted:

   Return the class number of the smallest class containing reg number REGNO.

   This could be a conditional expression or could index an array.

   ??? 0 is not really a register, but a constant.  */

#define REGNO_REG_CLASS(regno)                                          \

  ((0 == regno) ? ALL_REGS : ((1 <= regno) && (regno <= OR32_LAST_INT_REG))              \

   ? GENERAL_REGS : NO_REGS)

/* The class value for index registers, and the one for base regs.  */

#define INDEX_REG_CLASS GENERAL_REGS

#define BASE_REG_CLASS  GENERAL_REGS

/* Given an rtx X being reloaded into a reg required to be in class CLASS,

   return the class of reg to actually use.  In general this is just CLASS;

   but on some machines in some cases it is preferable to use a more

   restrictive class.  */

#define PREFERRED_RELOAD_CLASS(X,CLASS)  (CLASS)

/* Return the maximum number of consecutive registers needed to represent mode

   MODE in a register of class CLASS.

   On the or32, this is always the size of MODE in words, since all registers

   are the same size.  */

#define CLASS_MAX_NREGS(CLASS, MODE)                                    \

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

/* -------------------------------------------------------------------------- */

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

/* Define this if pushing a word on the stack makes the stack pointer a

   smaller address.  */

#define STACK_GROWS_DOWNWARD 1

/* Define this if the nominal address of the stack frame is at the

   high-address end of the local variables; that is, each additional local

   variable allocated goes at a more negative offset in the frame.  */

#define FRAME_GROWS_DOWNWARD 1

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

   FRAME_GROWS_DOWNWARD, this is the offset to the END of the first local

   allocated.  Otherwise, it is the offset to the BEGINNING of the first local

   allocated.  */

#define STARTING_FRAME_OFFSET 0

/* Offset of first parameter from the argument pointer register value.  */

#define FIRST_PARM_OFFSET(FNDECL) 0

/* Define this if stack space is still allocated for a parameter passed

   in a register.  The value is the number of bytes allocated to this

   area.

   No such allocation for OR32. */

/* #define REG_PARM_STACK_SPACE(FNDECL) (UNITS_PER_WORD * GP_ARG_NUM_REG) */

/* Define this if the above stack space is to be considered part of the

   space allocated by the caller.

   N/a for OR32. */

/* #define OUTGOING_REG_PARM_STACK_SPACE */

/* Define this macro if `REG_PARM_STACK_SPACE' is defined, but the

   stack parameters don't skip the area specified by it.

   N/a for OR32. */

/* #define STACK_PARMS_IN_REG_PARM_AREA */

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

   will be computed and placed into the variable

   current_function_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.

   Setting both PUSH_ARGS and ACCUMULATE_OUTGOING_ARGS is not proper.

   This is the approached used by OR32. */

#define ACCUMULATE_OUTGOING_ARGS 1

#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}}

#define INITIAL_ELIMINATION_OFFSET(FROM, TO, OFFSET) \

  (OFFSET) = or32_initial_elimination_offset ((FROM), (TO))

/* A C expression that should indicate the number of bytes of its own

   arguments that a function pops on returning, or 0 if the function pops no

   arguments and the caller must therefore pop them all after the function

   returns.

   "fundecl" is a C variable whose value is a tree node that describes the

   function in question. Normally it is a node of type FUNCTION_DECL that

   describes the declaration of the function. From this you can obtain the

   DECL_ATTRIBUTES of the function.

   "funtype" is a C variable whose value is a tree node that describes the

   function in question. Normally it is a node of type FUNCTION_TYPE that

   describes the data type of the function. From this it is possible to obtain

   the data types of the value and arguments (if known).

   When a call to a library function is being considered, "fundecl" will

   contain an identifier node for the library function. Thus, if you need to

   distinguish among various library functions, you can do so by their

   names. Note that “library function” in this context means a function used

   to perform arithmetic, whose name is known specially in the compiler and

   was not mentioned in the C code being compiled.

   "size" is the number of bytes of arguments passed on the stack. If a

   variable number of bytes is passed, it is zero, and argument popping will

   always be the re- sponsibility of the calling function.

   On the VAX, all functions always pop their arguments, so the definition of

   this macro is stack-size. On the 68000, using the standard calling

   convention, no functions pop their arguments, so the value of the macro is

   always 0 in this case. But an alternative calling convention is available

   in which functions that take a fixed number of argu- ments pop them but

   other functions (such as printf) pop nothing (the caller pops all). When

   this convention is in use, funtype is examined to determine whether a

   function takes a fixed number of arguments.

   On the OR32, no functions pop their arguments.

   JPB 29-Aug-10: Is this really correct? */

#define RETURN_POPS_ARGS(fundecl, funtype, size) 0

/* Minimum and maximum general purpose registers used to hold arguments.  */

#define GP_ARG_MIN_REG 3

#define GP_ARG_MAX_REG 8

#define GP_ARG_NUM_REG (GP_ARG_MAX_REG - GP_ARG_MIN_REG + 1) 

/* Return register */

#define GP_ARG_RETURN  11 

#define GP_ARG_RETURNH 12 

/* A C expression to create an RTX representing the place where a library

   function returns a value of mode mode.

   Note that “library function” in this context means a compiler support

   routine, used to perform arithmetic, whose name is known specially by the

   compiler and was not mentioned in the C code being compiled.

   For the OR32, return value is in R11 (GP_ARG_RETURN).  */

#define LIBCALL_VALUE(mode)                                             \

  gen_rtx_REG(                                                          \

           ((GET_MODE_CLASS (mode) != MODE_INT                          \

             || GET_MODE_SIZE (mode) >= 4)                              \

            ? (mode)                                                    \

            : SImode),                                                  \

            GP_ARG_RETURN)

/* Define this if PCC uses the nonreentrant convention for returning

   structure and union values.

   Not needed for OR32. */

/*#define PCC_STATIC_STRUCT_RETURN */

/* 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. So for most machines, this definition suffices:

       #define FUNCTION_VALUE_REGNO_P(N) ((N) == 0)

   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.

   For OR32, we must check if we have the return register.

   From GCC 4.6, this will be replaced by TARGET_FUNCION_VALUE_REGNO_P target

   hook function. */

#define FUNCTION_VALUE_REGNO_P(N)  ((N) == GP_ARG_RETURN)

/* 1 if N is a possible register number for function argument passing. */

#define FUNCTION_ARG_REGNO_P(N) \

   ((N) >= GP_ARG_MIN_REG && (N) <= GP_ARG_MAX_REG)

/* A code distinguishing the floating point format of the target

   machine.  There are three defined values: IEEE_FLOAT_FORMAT,

   VAX_FLOAT_FORMAT, and UNKNOWN_FLOAT_FORMAT.  */

#define TARGET_FLOAT_FORMAT IEEE_FLOAT_FORMAT

#define FLOAT_WORDS_BIG_ENDIAN 1

/* A C type for declaring a variable that is used as the first argument of

   FUNCTION_ARG and other related values. For some target machines, the type

   int suffices and can hold the number of bytes of argument so far.

   There is no need to record in CUMULATIVE_ARGS anything about the arguments

   that have been passed on the stack. The compiler has other variables to

   keep track of that.  For target machines on which all arguments are passed

   on the stack, there is no need to store anything in CUMULATIVE_ARGS;

   however, the data structure must exist and should not be empty, so use

   int. */

#define CUMULATIVE_ARGS int

/* A C statement (sans semicolon) for initializing the variable "cum" for the

   state at the beginning of the argument list. The variable has type

   CUMULATIVE_ARGS. The value of "fntype" is the tree node for the data type

   of the function which will receive the args, or 0 if the args are to a

   compiler support library function. For direct calls that are not libcalls,

   "fndecl" contain the declaration node of the function. "fndecl" is also set

   when INIT_CUMULATIVE_ARGS is used to find arguments for the function being

   compiled.  "n_named_args" is set to the number of named arguments,

   including a structure return address if it is passed as a parameter, when

   making a call. When processing incoming arguments, "n_named_args" is set to

   −1.

   When processing a call to a compiler support library function, "libname"

   identifies which one. It is a symbol_ref rtx which contains the name of the

   function, as a string. "libname" is 0 when an ordinary C function call is

   being processed. Thus, each time this macro is called, either "libname" or

   "fntype" is nonzero, but never both of them at once.

   For the OR32, we set "cum" to zero each time.

   JPB 29-Aug-10: Is this correct? */

#define INIT_CUMULATIVE_ARGS(cum, fntype, libname, fndecl, n_named_args) \

  (cum = 0)

/* -------------------------------------------------------------------------- */

/* Define intermediate macro to compute the size (in registers) of an argument

   for the or32.

   The OR32_ROUND_ADVANCE* macros are local to this file.  */

/* Round "size" up to a word boundary.  */

#define OR32_ROUND_ADVANCE(size)                                        \

  (((size) + UNITS_PER_WORD - 1) / UNITS_PER_WORD)

/* Round arg "mode"/"type" up to the next word boundary.  */

#define OR32_ROUND_ADVANCE_ARG(mode, type)                              \

  ((mode) == BLKmode                                                    \

   ? OR32_ROUND_ADVANCE (int_size_in_bytes (type))                      \

   : OR32_ROUND_ADVANCE (GET_MODE_SIZE (mode)))

/* Round "cum" up to the necessary point for argument "mode"/"type".  This is

   either rounded to nearest reg or nearest double-reg boundary */

#define OR32_ROUND_ADVANCE_CUM(cum, mode, type)                         \

  ((((mode) == BLKmode ? TYPE_ALIGN (type) : GET_MODE_BITSIZE (mode))   \

    > BITS_PER_WORD)                                                    \

   ? (((cum) + 1) & ~1)                                                 \

   : (cum))

/* 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)                    \

  ((cum) = (OR32_ROUND_ADVANCE_CUM ((cum), (mode), (type))              \

            + OR32_ROUND_ADVANCE_ARG ((mode), (type))))

/* Return boolean indicating if arg of type "type" and mode "mode" will be

   passed in a reg.  This includes arguments that have to be passed by

   reference as the pointer to them is passed in a reg if one is available

   (and that is what we're given).

   When passing arguments "named" is always 1.  When receiving arguments

   "named" is 1 for each argument except the last in a stdarg/varargs

   function.  In a stdarg function we want to treat the last named arg as

   named.  In a varargs function we want to treat the last named arg (which is

   `__builtin_va_alist') as unnamed.

   This macro is only used in this file.  */

#define OR32_PASS_IN_REG_P(cum, mode, type, named)                      \

  ((named)                                                              \

   && ((OR32_ROUND_ADVANCE_CUM ((cum), (mode), (type))                  \

        + OR32_ROUND_ADVANCE_ARG ((mode), (type))                       \

        <= GP_ARG_NUM_REG)))

/* Determine where to put an argument to a function.  Value is zero to push

   the argument on the stack, or a hard register in which to store the

   argument.

   "mode" is the argument's machine mode.

   "type" is the data type of the argument (as a tree).  This is null for

    libcalls where that information may not be available.

   "cum" is a variable of type CUMULATIVE_ARGS which gives info about the

    preceding args and about the function being called.

   "named" is nonzero if this argument is a named parameter (otherwise it is

    an extra parameter matching an ellipsis).

    On the ARC the first MAX_ARC_PARM_REGS args are normally in registers and

    the rest are pushed.  */

#define FUNCTION_ARG(cum, mode, type, named)                            \

  (OR32_PASS_IN_REG_P ((cum), (mode), (type), (named))                  \

   ? gen_rtx_REG ((mode),                                               \

                  OR32_ROUND_ADVANCE_CUM ((cum), (mode), (type))        \

                  + GP_ARG_MIN_REG)                                     \

   : 0)

/* Output assembler code to FILE to increment profiler label # LABELNO

   for profiling a function entry.

   JPB 29-Aug-10: This patently doesn't work. It is not even OR32 code! */

#define FUNCTION_PROFILER(FILE, LABELNO)  \

   fprintf (FILE, "\tl.load32u\tr0,LP%d\n\tcall\tmcount\n", (LABELNO));

/* EXIT_IGNORE_STACK should be nonzero if, when returning from a function, the

   stack pointer does not matter.  The value is tested only in functions that

   have frame pointers.  No definition is equivalent to always zero.

   The default suffices for OR32. */

#define EXIT_IGNORE_STACK 0

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

   incoming return address at the beginning of any function, before the

   prologue.  This RTL is either a REG, indicating that the return

   value is saved in REG, or a MEM representing a location in

   the stack.  */

#define INCOMING_RETURN_ADDR_RTX gen_rtx_REG (Pmode, LINK_REGNUM)

#define RETURN_ADDR_RTX(COUNT, FP) \

  ((COUNT) ? NULL_RTX : get_hard_reg_initial_val (Pmode, LINK_REGNUM))

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

/* #define HAVE_POST_INCREMENT */

/* #define HAVE_POST_DECREMENT */

/* #define HAVE_PRE_DECREMENT */

/* #define HAVE_PRE_INCREMENT */

/* Macros to check register numbers against specific register classes.  */

#define MAX_REGS_PER_ADDRESS 1

/* True if X is an rtx for a constant that is a valid address.

   JPB 29-Aug-10: Why is the default implementation not OK? */

#define CONSTANT_ADDRESS_P(X)                                           \

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