Subversion Repositories openrisc_2011-10-31

/* Interface definition for configurable Xtensa ISA support.

   Copyright 2003, 2004, 2005, 2006, 2008 Free Software Foundation, Inc.

   This file is part of BFD, the Binary File Descriptor library.

   This program 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 2 of the License, or

   (at your option) any later version.

   This program 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 this program; if not, write to the Free Software

   Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301,

   USA.  */

#ifndef XTENSA_LIBISA_H

#define XTENSA_LIBISA_H

#ifdef __cplusplus

extern "C" {

#endif

/* Version number: This is intended to help support code that works with

   versions of this library from multiple Xtensa releases.  */

#define XTENSA_ISA_VERSION 7000

#ifndef uint32

#define uint32 unsigned int

#endif

/* This file defines the interface to the Xtensa ISA library.  This

   library contains most of the ISA-specific information for a

   particular Xtensa processor.  For example, the set of valid

   instructions, their opcode encodings and operand fields are all

   included here.

   This interface basically defines a number of abstract data types.

   . an instruction buffer - for holding the raw instruction bits

   . ISA info - information about the ISA as a whole

   . instruction formats - instruction size and slot structure

   . opcodes - information about individual instructions

   . operands - information about register and immediate instruction operands

   . stateOperands - information about processor state instruction operands

   . interfaceOperands - information about interface instruction operands

   . register files - register file information

   . processor states - internal processor state information

   . system registers - "special registers" and "user registers"

   . interfaces - TIE interfaces that are external to the processor

   . functional units - TIE shared functions

   The interface defines a set of functions to access each data type.

   With the exception of the instruction buffer, the internal

   representations of the data structures are hidden.  All accesses must

   be made through the functions defined here.  */

typedef struct xtensa_isa_opaque { int unused; } *xtensa_isa;

/* Most of the Xtensa ISA entities (e.g., opcodes, regfiles, etc.) are

   represented here using sequential integers beginning with 0.  The

   specific values are only fixed for a particular instantiation of an

   xtensa_isa structure, so these values should only be used

   internally.  */

typedef int xtensa_opcode;

typedef int xtensa_format;

typedef int xtensa_regfile;

typedef int xtensa_state;

typedef int xtensa_sysreg;

typedef int xtensa_interface;

typedef int xtensa_funcUnit;

/* Define a unique value for undefined items.  */

#define XTENSA_UNDEFINED -1

/* Overview of using this interface to decode/encode instructions:

   Each Xtensa instruction is associated with a particular instruction

   format, where the format defines a fixed number of slots for

   operations.  The formats for the core Xtensa ISA have only one slot,

   but FLIX instructions may have multiple slots.  Within each slot,

   there is a single opcode and some number of associated operands.

   The encoding and decoding functions operate on instruction buffers,

   not on the raw bytes of the instructions.  The same instruction

   buffer data structure is used for both entire instructions and

   individual slots in those instructions -- the contents of a slot need

   to be extracted from or inserted into the buffer for the instruction

   as a whole.

   Decoding an instruction involves first finding the format, which

   identifies the number of slots, and then decoding each slot

   separately.  A slot is decoded by finding the opcode and then using

   the opcode to determine how many operands there are.  For example:

   xtensa_insnbuf_from_chars

   xtensa_format_decode

   for each slot {

     xtensa_format_get_slot

     xtensa_opcode_decode

     for each operand {

       xtensa_operand_get_field

       xtensa_operand_decode

     }

   }

   Encoding an instruction is roughly the same procedure in reverse:

   xtensa_format_encode

   for each slot {

     xtensa_opcode_encode

     for each operand {

       xtensa_operand_encode

       xtensa_operand_set_field

     }

     xtensa_format_set_slot

   }

   xtensa_insnbuf_to_chars

*/

/* Error handling.  */

/* Error codes.  The code for the most recent error condition can be

   retrieved with the "errno" function.  For any result other than

   xtensa_isa_ok, an error message containing additional information

   about the problem can be retrieved using the "error_msg" function.

   The error messages are stored in an internal buffer, which should

   not be freed and may be overwritten by subsequent operations.  */

typedef enum xtensa_isa_status_enum

{

  xtensa_isa_ok = 0,

  xtensa_isa_bad_format,

  xtensa_isa_bad_slot,

  xtensa_isa_bad_opcode,

  xtensa_isa_bad_operand,

  xtensa_isa_bad_field,

  xtensa_isa_bad_iclass,

  xtensa_isa_bad_regfile,

  xtensa_isa_bad_sysreg,

  xtensa_isa_bad_state,

  xtensa_isa_bad_interface,

  xtensa_isa_bad_funcUnit,

  xtensa_isa_wrong_slot,

  xtensa_isa_no_field,

  xtensa_isa_out_of_memory,

  xtensa_isa_buffer_overflow,

  xtensa_isa_internal_error,

  xtensa_isa_bad_value

} xtensa_isa_status;

extern xtensa_isa_status

xtensa_isa_errno (xtensa_isa isa);

extern char *

xtensa_isa_error_msg (xtensa_isa isa);

/* Instruction buffers.  */

typedef uint32 xtensa_insnbuf_word;

typedef xtensa_insnbuf_word *xtensa_insnbuf;

/* Get the size in "insnbuf_words" of the xtensa_insnbuf array.  */

extern int

xtensa_insnbuf_size (xtensa_isa isa);

/* Allocate an xtensa_insnbuf of the right size.  */

extern xtensa_insnbuf

xtensa_insnbuf_alloc (xtensa_isa isa);

/* Release an xtensa_insnbuf.  */

extern void

xtensa_insnbuf_free (xtensa_isa isa, xtensa_insnbuf buf);

/* Conversion between raw memory (char arrays) and our internal

   instruction representation.  This is complicated by the Xtensa ISA's

   variable instruction lengths.  When converting to chars, the buffer

   must contain a valid instruction so we know how many bytes to copy;

   thus, the "to_chars" function returns the number of bytes copied or

   XTENSA_UNDEFINED on error.  The "from_chars" function first reads the

   minimal number of bytes required to decode the instruction length and

   then proceeds to copy the entire instruction into the buffer; if the

   memory does not contain a valid instruction, it copies the maximum

   number of bytes required for the longest Xtensa instruction.  The

   "num_chars" argument may be used to limit the number of bytes that

   can be read or written.  Otherwise, if "num_chars" is zero, the

   functions may read or write past the end of the code.  */

extern int

xtensa_insnbuf_to_chars (xtensa_isa isa, const xtensa_insnbuf insn,

                         unsigned char *cp, int num_chars);

extern void

xtensa_insnbuf_from_chars (xtensa_isa isa, xtensa_insnbuf insn,

                           const unsigned char *cp, int num_chars);

/* ISA information.  */

/* Initialize the ISA information.  */

extern xtensa_isa

xtensa_isa_init (xtensa_isa_status *errno_p, char **error_msg_p);

/* Deallocate an xtensa_isa structure.  */

extern void

xtensa_isa_free (xtensa_isa isa);

/* Get the maximum instruction size in bytes.  */

extern int

xtensa_isa_maxlength (xtensa_isa isa);

/* Decode the length in bytes of an instruction in raw memory (not an

   insnbuf).  This function reads only the minimal number of bytes

   required to decode the instruction length.  Returns

   XTENSA_UNDEFINED on error.  */

extern int

xtensa_isa_length_from_chars (xtensa_isa isa, const unsigned char *cp);

/* Get the number of stages in the processor's pipeline.  The pipeline

   stage values returned by other functions in this library will range

   from 0 to N-1, where N is the value returned by this function.

   Note that the stage numbers used here may not correspond to the

   actual processor hardware, e.g., the hardware may have additional

   stages before stage 0.  Returns XTENSA_UNDEFINED on error.  */

extern int

xtensa_isa_num_pipe_stages (xtensa_isa isa);

/* Get the number of various entities that are defined for this processor.  */

extern int

xtensa_isa_num_formats (xtensa_isa isa);

extern int

xtensa_isa_num_opcodes (xtensa_isa isa);

extern int

xtensa_isa_num_regfiles (xtensa_isa isa);

extern int

xtensa_isa_num_states (xtensa_isa isa);

extern int

xtensa_isa_num_sysregs (xtensa_isa isa);

extern int

xtensa_isa_num_interfaces (xtensa_isa isa);

extern int

xtensa_isa_num_funcUnits (xtensa_isa isa);

/* Instruction formats.  */

/* Get the name of a format.  Returns null on error.  */

extern const char *

xtensa_format_name (xtensa_isa isa, xtensa_format fmt);

/* Given a format name, return the format number.  Returns

   XTENSA_UNDEFINED if the name is not a valid format.  */

extern xtensa_format

xtensa_format_lookup (xtensa_isa isa, const char *fmtname);

/* Decode the instruction format from a binary instruction buffer.

   Returns XTENSA_UNDEFINED if the format is not recognized.  */

extern xtensa_format

xtensa_format_decode (xtensa_isa isa, const xtensa_insnbuf insn);

/* Set the instruction format field(s) in a binary instruction buffer.

   All the other fields are set to zero.  Returns non-zero on error.  */

extern int

xtensa_format_encode (xtensa_isa isa, xtensa_format fmt, xtensa_insnbuf insn);

/* Find the length (in bytes) of an instruction.  Returns

   XTENSA_UNDEFINED on error.  */

extern int

xtensa_format_length (xtensa_isa isa, xtensa_format fmt);

/* Get the number of slots in an instruction.  Returns XTENSA_UNDEFINED

   on error.  */

extern int

xtensa_format_num_slots (xtensa_isa isa, xtensa_format fmt);

/* Get the opcode for a no-op in a particular slot.

   Returns XTENSA_UNDEFINED on error.  */

extern xtensa_opcode

xtensa_format_slot_nop_opcode (xtensa_isa isa, xtensa_format fmt, int slot);

/* Get the bits for a specified slot out of an insnbuf for the

   instruction as a whole and put them into an insnbuf for that one

   slot, and do the opposite to set a slot.  Return non-zero on error.  */

extern int

xtensa_format_get_slot (xtensa_isa isa, xtensa_format fmt, int slot,

                        const xtensa_insnbuf insn, xtensa_insnbuf slotbuf);

extern int

xtensa_format_set_slot (xtensa_isa isa, xtensa_format fmt, int slot,

                        xtensa_insnbuf insn, const xtensa_insnbuf slotbuf);

/* Opcode information.  */

/* Translate a mnemonic name to an opcode.  Returns XTENSA_UNDEFINED if

   the name is not a valid opcode mnemonic.  */

extern xtensa_opcode

xtensa_opcode_lookup (xtensa_isa isa, const char *opname);

/* Decode the opcode for one instruction slot from a binary instruction

   buffer.  Returns the opcode or XTENSA_UNDEFINED if the opcode is

   illegal.  */

extern xtensa_opcode

xtensa_opcode_decode (xtensa_isa isa, xtensa_format fmt, int slot,

                      const xtensa_insnbuf slotbuf);

/* Set the opcode field(s) for an instruction slot.  All other fields

   in the slot are set to zero.  Returns non-zero if the opcode cannot

   be encoded.  */

extern int

xtensa_opcode_encode (xtensa_isa isa, xtensa_format fmt, int slot,

                      xtensa_insnbuf slotbuf, xtensa_opcode opc);

/* Get the mnemonic name for an opcode.  Returns null on error.  */

extern const char *

xtensa_opcode_name (xtensa_isa isa, xtensa_opcode opc);

/* Check various properties of opcodes.  These functions return 0 if

   the condition is false, 1 if the condition is true, and

   XTENSA_UNDEFINED on error.  The instructions are classified as

   follows:

   branch: conditional branch; may fall through to next instruction (B*)

   jump: unconditional branch (J, JX, RET*, RF*)

   loop: zero-overhead loop (LOOP*)

   call: unconditional call; control returns to next instruction (CALL*)

   For the opcodes that affect control flow in some way, the branch

   target may be specified by an immediate operand or it may be an

   address stored in a register.  You can distinguish these by

   checking if the instruction has a PC-relative immediate

   operand.  */

extern int

xtensa_opcode_is_branch (xtensa_isa isa, xtensa_opcode opc);

extern int

xtensa_opcode_is_jump (xtensa_isa isa, xtensa_opcode opc);

extern int

xtensa_opcode_is_loop (xtensa_isa isa, xtensa_opcode opc);

extern int

xtensa_opcode_is_call (xtensa_isa isa, xtensa_opcode opc);

/* Find the number of ordinary operands, state operands, and interface

   operands for an instruction.  These return XTENSA_UNDEFINED on

   error.  */

extern int

xtensa_opcode_num_operands (xtensa_isa isa, xtensa_opcode opc);

extern int

xtensa_opcode_num_stateOperands (xtensa_isa isa, xtensa_opcode opc);

extern int

xtensa_opcode_num_interfaceOperands (xtensa_isa isa, xtensa_opcode opc);

/* Get functional unit usage requirements for an opcode.  Each "use"

   is identified by a <functional unit, pipeline stage> pair.  The

   "num_funcUnit_uses" function returns the number of these "uses" or

   XTENSA_UNDEFINED on error.  The "funcUnit_use" function returns

   a pointer to a "use" pair or null on error.  */

typedef struct xtensa_funcUnit_use_struct

{

  xtensa_funcUnit unit;

  int stage;

} xtensa_funcUnit_use;

extern int

xtensa_opcode_num_funcUnit_uses (xtensa_isa isa, xtensa_opcode opc);

extern xtensa_funcUnit_use *

xtensa_opcode_funcUnit_use (xtensa_isa isa, xtensa_opcode opc, int u);

/* Operand information.  */

/* Get the name of an operand.  Returns null on error.  */

extern const char *

xtensa_operand_name (xtensa_isa isa, xtensa_opcode opc, int opnd);

/* Some operands are "invisible", i.e., not explicitly specified in

   assembly language.  When assembling an instruction, you need not set

   the values of invisible operands, since they are either hardwired or

   derived from other field values.  The values of invisible operands

   can be examined in the same way as other operands, but remember that

   an invisible operand may get its value from another visible one, so

   the entire instruction must be available before examining the

   invisible operand values.  This function returns 1 if an operand is

   visible, 0 if it is invisible, or XTENSA_UNDEFINED on error.  Note

   that whether an operand is visible is orthogonal to whether it is

   "implicit", i.e., whether it is encoded in a field in the

   instruction.  */

extern int

xtensa_operand_is_visible (xtensa_isa isa, xtensa_opcode opc, int opnd);

/* Check if an operand is an input ('i'), output ('o'), or inout ('m')

   operand.  Note: The output operand of a conditional assignment

   (e.g., movnez) appears here as an inout ('m') even if it is declared

   in the TIE code as an output ('o'); this allows the compiler to

   properly handle register allocation for conditional assignments.

   Returns 0 on error.  */

extern char

xtensa_operand_inout (xtensa_isa isa, xtensa_opcode opc, int opnd);

/* Get and set the raw (encoded) value of the field for the specified

   operand.  The "set" function does not check if the value fits in the

   field; that is done by the "encode" function below.  Both of these

   functions return non-zero on error, e.g., if the field is not defined

   for the specified slot.  */

extern int

xtensa_operand_get_field (xtensa_isa isa, xtensa_opcode opc, int opnd,

                          xtensa_format fmt, int slot,

                          const xtensa_insnbuf slotbuf, uint32 *valp);

extern int

xtensa_operand_set_field (xtensa_isa isa, xtensa_opcode opc, int opnd,

                          xtensa_format fmt, int slot,

                          xtensa_insnbuf slotbuf, uint32 val);

/* Encode and decode operands.  The raw bits in the operand field may

   be encoded in a variety of different ways.  These functions hide

   the details of that encoding.  The result values are returned through

   the argument pointer.  The return value is non-zero on error.  */

extern int

xtensa_operand_encode (xtensa_isa isa, xtensa_opcode opc, int opnd,

                       uint32 *valp);

extern int

xtensa_operand_decode (xtensa_isa isa, xtensa_opcode opc, int opnd,

                       uint32 *valp);

/* An operand may be either a register operand or an immediate of some

   sort (e.g., PC-relative or not).  The "is_register" function returns

   XTENSA_UNDEFINED on error.  The "regfile" function returns the

   regfile for a register operand, or XTENSA_UNDEFINED on error.  */

extern int

xtensa_operand_is_register (xtensa_isa isa, xtensa_opcode opc, int opnd);

extern xtensa_regfile

xtensa_operand_regfile (xtensa_isa isa, xtensa_opcode opc, int opnd);

/* Register operands may span multiple consecutive registers, e.g., a

   64-bit data type may occupy two 32-bit registers.  Only the first

   register is encoded in the operand field.  This function specifies

   the number of consecutive registers occupied by this operand.  For

   non-register operands, the return value is undefined.  Returns

   XTENSA_UNDEFINED on error.  */

extern int

xtensa_operand_num_regs (xtensa_isa isa, xtensa_opcode opc, int opnd);

/* Some register operands do not completely identify the register being

   accessed.  For example, the operand value may be added to an internal

   state value.  By definition, this implies that the corresponding

   regfile is not allocatable.  Unknown registers should generally be

   treated with worst-case assumptions.  The function returns 0 if the

   register value is unknown, 1 if known, and XTENSA_UNDEFINED on

   error.  */

extern int

xtensa_operand_is_known_reg (xtensa_isa isa, xtensa_opcode opc, int opnd);

/* Check if an immediate operand is PC-relative.  Returns 0 for register

   operands and non-PC-relative immediates, 1 for PC-relative

   immediates, and XTENSA_UNDEFINED on error.  */

extern int

xtensa_operand_is_PCrelative (xtensa_isa isa, xtensa_opcode opc, int opnd);

/* For PC-relative offset operands, the interpretation of the offset may

   vary between opcodes, e.g., is it relative to the current PC or that

   of the next instruction?  The following functions are defined to

   perform PC-relative relocations and to undo them (as in the

   disassembler).  The "do_reloc" function takes the desired address

   value and the PC of the current instruction and sets the value to the

   corresponding PC-relative offset (which can then be encoded and

   stored into the operand field).  The "undo_reloc" function takes the

   unencoded offset value and the current PC and sets the value to the

   appropriate address.  The return values are non-zero on error.  Note

   that these functions do not replace the encode/decode functions; the

   operands must be encoded/decoded separately and the encode functions

   are responsible for detecting invalid operand values.  */

extern int

xtensa_operand_do_reloc (xtensa_isa isa, xtensa_opcode opc, int opnd,

                         uint32 *valp, uint32 pc);

extern int

xtensa_operand_undo_reloc (xtensa_isa isa, xtensa_opcode opc, int opnd,

                           uint32 *valp, uint32 pc);

/* State Operands.  */

/* Get the state accessed by a state operand.  Returns XTENSA_UNDEFINED

   on error.  */

extern xtensa_state

xtensa_stateOperand_state (xtensa_isa isa, xtensa_opcode opc, int stOp);

/* Check if a state operand is an input ('i'), output ('o'), or inout

   ('m') operand.  Returns 0 on error.  */

extern char

xtensa_stateOperand_inout (xtensa_isa isa, xtensa_opcode opc, int stOp);

/* Interface Operands.  */

/* Get the external interface accessed by an interface operand.

   Returns XTENSA_UNDEFINED on error.  */

extern xtensa_interface

xtensa_interfaceOperand_interface (xtensa_isa isa, xtensa_opcode opc,

                                   int ifOp);

/* Register Files.  */

/* Regfiles include both "real" regfiles and "views", where a view

   allows a group of adjacent registers in a real "parent" regfile to be

   viewed as a single register.  A regfile view has all the same

   properties as its parent except for its (long) name, bit width, number

   of entries, and default ctype.  You can use the parent function to

   distinguish these two classes.  */

/* Look up a regfile by either its name or its abbreviated "short name".

   Returns XTENSA_UNDEFINED on error.  The "lookup_shortname" function

   ignores "view" regfiles since they always have the same shortname as

   their parents.  */

extern xtensa_regfile

xtensa_regfile_lookup (xtensa_isa isa, const char *name);

extern xtensa_regfile

xtensa_regfile_lookup_shortname (xtensa_isa isa, const char *shortname);

/* Get the name or abbreviated "short name" of a regfile.

   Returns null on error.  */

extern const char *

xtensa_regfile_name (xtensa_isa isa, xtensa_regfile rf);

extern const char *

xtensa_regfile_shortname (xtensa_isa isa, xtensa_regfile rf);

/* Get the parent regfile of a "view" regfile.  If the regfile is not a

   view, the result is the same as the input parameter.  Returns

   XTENSA_UNDEFINED on error.  */

extern xtensa_regfile

xtensa_regfile_view_parent (xtensa_isa isa, xtensa_regfile rf);

/* Get the bit width of a regfile or regfile view.

   Returns XTENSA_UNDEFINED on error.  */

extern int

xtensa_regfile_num_bits (xtensa_isa isa, xtensa_regfile rf);

/* Get the number of regfile entries.  Returns XTENSA_UNDEFINED on

   error.  */

extern int

xtensa_regfile_num_entries (xtensa_isa isa, xtensa_regfile rf);

/* Processor States.  */

/* Look up a state by name.  Returns XTENSA_UNDEFINED on error.  */

extern xtensa_state

xtensa_state_lookup (xtensa_isa isa, const char *name);

/* Get the name for a processor state.  Returns null on error.  */

extern const char *

xtensa_state_name (xtensa_isa isa, xtensa_state st);

/* Get the bit width for a processor state.

   Returns XTENSA_UNDEFINED on error.  */

extern int

xtensa_state_num_bits (xtensa_isa isa, xtensa_state st);

/* Check if a state is exported from the processor core.  Returns 0 if

   the condition is false, 1 if the condition is true, and

   XTENSA_UNDEFINED on error.  */

extern int

xtensa_state_is_exported (xtensa_isa isa, xtensa_state st);

/* Check for a "shared_or" state.  Returns 0 if the condition is false,

   1 if the condition is true, and XTENSA_UNDEFINED on error.  */

extern int

xtensa_state_is_shared_or (xtensa_isa isa, xtensa_state st);

/* Sysregs ("special registers" and "user registers").  */

/* Look up a register by its number and whether it is a "user register"

   or a "special register".  Returns XTENSA_UNDEFINED if the sysreg does

   not exist.  */

extern xtensa_sysreg

xtensa_sysreg_lookup (xtensa_isa isa, int num, int is_user);

/* Check if there exists a sysreg with a given name.

   If not, this function returns XTENSA_UNDEFINED.  */

extern xtensa_sysreg

xtensa_sysreg_lookup_name (xtensa_isa isa, const char *name);

/* Get the name of a sysreg.  Returns null on error.  */

extern const char *

xtensa_sysreg_name (xtensa_isa isa, xtensa_sysreg sysreg);

/* Get the register number.  Returns XTENSA_UNDEFINED on error.  */

extern int

xtensa_sysreg_number (xtensa_isa isa, xtensa_sysreg sysreg);

/* Check if a sysreg is a "special register" or a "user register".

   Returns 0 for special registers, 1 for user registers and

   XTENSA_UNDEFINED on error.  */

extern int

xtensa_sysreg_is_user (xtensa_isa isa, xtensa_sysreg sysreg);

/* Interfaces.  */

/* Find an interface by name.  The return value is XTENSA_UNDEFINED if

   the specified interface is not found.  */

extern xtensa_interface

xtensa_interface_lookup (xtensa_isa isa, const char *ifname);

/* Get the name of an interface.  Returns null on error.  */

extern const char *

xtensa_interface_name (xtensa_isa isa, xtensa_interface intf);

/* Get the bit width for an interface.

   Returns XTENSA_UNDEFINED on error.  */

extern int

xtensa_interface_num_bits (xtensa_isa isa, xtensa_interface intf);

/* Check if an interface is an input ('i') or output ('o') with respect

   to the Xtensa processor core.  Returns 0 on error.  */

extern char

xtensa_interface_inout (xtensa_isa isa, xtensa_interface intf);

/* Check if accessing an interface has potential side effects.

   Currently "data" interfaces have side effects and "control"

   interfaces do not.  Returns 1 if there are side effects, 0 if not,

   and XTENSA_UNDEFINED on error.  */

extern int

xtensa_interface_has_side_effect (xtensa_isa isa, xtensa_interface intf);

/* Some interfaces may be related such that accessing one interface

   has side effects on a set of related interfaces.  The interfaces

   are partitioned into equivalence classes of related interfaces, and

   each class is assigned a unique identifier number.  This function

   returns the class identifier for an interface, or XTENSA_UNDEFINED

   on error.  These identifiers can be compared to determine if two

   interfaces are related; the specific values of the identifiers have

   no particular meaning otherwise.  */

extern int

xtensa_interface_class_id (xtensa_isa isa, xtensa_interface intf);

/* Functional Units.  */

/* Find a functional unit by name.  The return value is XTENSA_UNDEFINED if

   the specified unit is not found.  */

extern xtensa_funcUnit

xtensa_funcUnit_lookup (xtensa_isa isa, const char *fname);

/* Get the name of a functional unit.  Returns null on error.  */

extern const char *

xtensa_funcUnit_name (xtensa_isa isa, xtensa_funcUnit fun);

/* Functional units may be replicated.  See how many instances of a

   particular function unit exist.  Returns XTENSA_UNDEFINED on error.  */

extern int

xtensa_funcUnit_num_copies (xtensa_isa isa, xtensa_funcUnit fun);

#ifdef __cplusplus

}

#endif

#endif /* XTENSA_LIBISA_H */