231 lines
9.2 KiB
C
231 lines
9.2 KiB
C
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/* Interface definition for configurable Xtensa ISA support.
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Copyright 2003 Free Software Foundation, Inc.
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This file is part of BFD, the Binary File Descriptor library.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
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#ifndef XTENSA_LIBISA_H
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#define XTENSA_LIBISA_H
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/* Use the statically-linked version for the GNU tools. */
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#define STATIC_LIBISA 1
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#ifdef __cplusplus
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extern "C" {
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#endif
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#ifndef uint32
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#define uint32 unsigned int
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#endif
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/* This file defines the interface to the Xtensa ISA library. This library
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contains most of the ISA-specific information for a particular Xtensa
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processor. For example, the set of valid instructions, their opcode
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encodings and operand fields are all included here. To support Xtensa's
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configurability and user-defined instruction extensions (i.e., TIE), the
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library is initialized by loading one or more dynamic libraries; only a
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small set of interface code is present in the statically-linked portion
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of the library.
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This interface basically defines four abstract data types.
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. an instruction buffer - for holding the raw instruction bits
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. ISA info - information about the ISA as a whole
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. opcode info - information about individual instructions
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. operand info - information about specific instruction operands
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It would be nice to implement these as classes in C++, but the library is
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implemented in C to match the expectations of the GNU tools.
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Instead, the interface defines a set of functions to access each data
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type. With the exception of the instruction buffer, the internal
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representations of the data structures are hidden. All accesses must be
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made through the functions defined here. */
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typedef void* xtensa_isa;
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typedef void* xtensa_operand;
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/* Opcodes are represented here using sequential integers beginning with 0.
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The specific value used for a particular opcode is only fixed for a
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particular instantiation of an xtensa_isa structure, so these values
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should only be used internally. */
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typedef int xtensa_opcode;
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/* Define a unique value for undefined opcodes ("static const int" doesn't
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seem to work for this because EGCS 1.0.3 on i686-Linux without -O won't
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allow it to be used as an initializer). */
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#define XTENSA_UNDEFINED -1
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typedef int libisa_module_specifier;
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extern xtensa_isa xtensa_isa_init (void);
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/* Instruction buffers. */
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typedef uint32 xtensa_insnbuf_word;
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typedef xtensa_insnbuf_word *xtensa_insnbuf;
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/* Get the size in words of the xtensa_insnbuf array. */
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extern int xtensa_insnbuf_size (xtensa_isa);
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/* Allocate (with malloc) an xtensa_insnbuf of the right size. */
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extern xtensa_insnbuf xtensa_insnbuf_alloc (xtensa_isa);
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/* Release (with free) an xtensa_insnbuf of the right size. */
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extern void xtensa_insnbuf_free (xtensa_insnbuf);
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/* Inward and outward conversion from memory images (byte streams) to our
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internal instruction representation. */
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extern void xtensa_insnbuf_to_chars (xtensa_isa, const xtensa_insnbuf,
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char *);
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extern void xtensa_insnbuf_from_chars (xtensa_isa, xtensa_insnbuf,
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const char *);
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/* ISA information. */
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/* Load the ISA information from a shared library. If successful, this returns
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a value which identifies the ISA for use in subsequent calls to the ISA
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library; otherwise, it returns NULL. Multiple ISAs can be loaded to support
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heterogeneous multiprocessor systems. */
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extern xtensa_isa xtensa_load_isa (libisa_module_specifier);
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/* Extend an existing set of ISA information by loading an additional shared
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library of ISA information. This is primarily intended for loading TIE
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extensions. If successful, the return value is non-zero. */
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extern int xtensa_extend_isa (xtensa_isa, libisa_module_specifier);
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/* The default ISA. This variable is set automatically to the ISA most
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recently loaded and is provided as a convenience. An exception is the GNU
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opcodes library, where there is a fixed interface that does not allow
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passing the ISA as a parameter and the ISA must be taken from this global
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variable. (Note: Since this variable is just a convenience, it is not
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exported when libisa is built as a DLL, due to the hassle of dealing with
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declspecs.) */
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extern xtensa_isa xtensa_default_isa;
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/* Deallocate an xtensa_isa structure. */
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extern void xtensa_isa_free (xtensa_isa);
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/* Get the maximum instruction size in bytes. */
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extern int xtensa_insn_maxlength (xtensa_isa);
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/* Get the total number of opcodes for this processor. */
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extern int xtensa_num_opcodes (xtensa_isa);
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/* Translate a mnemonic name to an opcode. Returns XTENSA_UNDEFINED if
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the name is not a valid opcode mnemonic. */
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extern xtensa_opcode xtensa_opcode_lookup (xtensa_isa, const char *);
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/* Decode a binary instruction buffer. Returns the opcode or
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XTENSA_UNDEFINED if the instruction is illegal. */
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extern xtensa_opcode xtensa_decode_insn (xtensa_isa, const xtensa_insnbuf);
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/* Opcode information. */
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/* Set the opcode field(s) in a binary instruction buffer. The operand
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fields are set to zero. */
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extern void xtensa_encode_insn (xtensa_isa, xtensa_opcode, xtensa_insnbuf);
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/* Get the mnemonic name for an opcode. */
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extern const char * xtensa_opcode_name (xtensa_isa, xtensa_opcode);
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/* Find the length (in bytes) of an instruction. */
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extern int xtensa_insn_length (xtensa_isa, xtensa_opcode);
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/* Find the length of an instruction by looking only at the first byte. */
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extern int xtensa_insn_length_from_first_byte (xtensa_isa, char);
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/* Find the number of operands for an instruction. */
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extern int xtensa_num_operands (xtensa_isa, xtensa_opcode);
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/* Get the information about operand number "opnd" of a particular opcode. */
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extern xtensa_operand xtensa_get_operand (xtensa_isa, xtensa_opcode, int);
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/* Operand information. */
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/* Find the kind of operand. There are three possibilities:
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1) PC-relative immediates (e.g., "l", "L"). These can be identified with
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the xtensa_operand_isPCRelative function.
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2) non-PC-relative immediates ("i").
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3) register-file short names (e.g., "a", "b", "m" and others defined
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via TIE). */
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extern char * xtensa_operand_kind (xtensa_operand);
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/* Check if an operand is an input ('<'), output ('>'), or inout ('=')
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operand. Note: The output operand of a conditional assignment
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(e.g., movnez) appears here as an inout ('=') even if it is declared
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in the TIE code as an output ('>'); this allows the compiler to
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properly handle register allocation for conditional assignments. */
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extern char xtensa_operand_inout (xtensa_operand);
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/* Get and set the raw (encoded) value of the field for the specified
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operand. The "set" function does not check if the value fits in the
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field; that is done by the "encode" function below. */
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extern uint32 xtensa_operand_get_field (xtensa_operand, const xtensa_insnbuf);
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extern void xtensa_operand_set_field (xtensa_operand, xtensa_insnbuf, uint32);
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/* Encode and decode operands. The raw bits in the operand field
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may be encoded in a variety of different ways. These functions hide the
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details of that encoding. The encode function has a special return type
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(xtensa_encode_result) to indicate success or the reason for failure; the
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encoded value is returned through the argument pointer. The decode function
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has no possibility of failure and returns the decoded value. */
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typedef enum
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{
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xtensa_encode_result_ok,
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xtensa_encode_result_align,
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xtensa_encode_result_not_in_table,
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xtensa_encode_result_too_low,
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xtensa_encode_result_too_high,
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xtensa_encode_result_not_ok,
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xtensa_encode_result_max = xtensa_encode_result_not_ok
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} xtensa_encode_result;
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extern xtensa_encode_result xtensa_operand_encode (xtensa_operand, uint32 *);
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extern uint32 xtensa_operand_decode (xtensa_operand, uint32);
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/* For PC-relative offset operands, the interpretation of the offset may vary
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between opcodes, e.g., is it relative to the current PC or that of the next
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instruction? The following functions are defined to perform PC-relative
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relocations and to undo them (as in the disassembler). The first function
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takes the desired address and the PC of the current instruction and returns
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the unencoded value to be stored in the offset field. The second function
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takes the unencoded offset value and the current PC and returns the address.
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Note that these functions do not replace the encode/decode functions; the
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operands must be encoded/decoded separately. */
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extern int xtensa_operand_isPCRelative (xtensa_operand);
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extern uint32 xtensa_operand_do_reloc (xtensa_operand, uint32, uint32);
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extern uint32 xtensa_operand_undo_reloc (xtensa_operand, uint32, uint32);
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#ifdef __cplusplus
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}
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#endif
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#endif /* XTENSA_LIBISA_H */
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