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Diffstat (limited to 'include/xtensa-isa.h')
| -rw-r--r-- | include/xtensa-isa.h | 230 |
1 files changed, 230 insertions, 0 deletions
diff --git a/include/xtensa-isa.h b/include/xtensa-isa.h new file mode 100644 index 0000000..54f750c --- /dev/null +++ b/include/xtensa-isa.h @@ -0,0 +1,230 @@ +/* Interface definition for configurable Xtensa ISA support. + Copyright 2003 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ + +#ifndef XTENSA_LIBISA_H +#define XTENSA_LIBISA_H + +/* Use the statically-linked version for the GNU tools. */ +#define STATIC_LIBISA 1 + +#ifdef __cplusplus +extern "C" { +#endif + +#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. To support Xtensa's + configurability and user-defined instruction extensions (i.e., TIE), the + library is initialized by loading one or more dynamic libraries; only a + small set of interface code is present in the statically-linked portion + of the library. + + This interface basically defines four abstract data types. + + . an instruction buffer - for holding the raw instruction bits + . ISA info - information about the ISA as a whole + . opcode info - information about individual instructions + . operand info - information about specific instruction operands + + It would be nice to implement these as classes in C++, but the library is + implemented in C to match the expectations of the GNU tools. + Instead, 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 void* xtensa_isa; +typedef void* xtensa_operand; + + +/* Opcodes are represented here using sequential integers beginning with 0. + The specific value used for a particular opcode is only fixed for a + particular instantiation of an xtensa_isa structure, so these values + should only be used internally. */ +typedef int xtensa_opcode; + +/* Define a unique value for undefined opcodes ("static const int" doesn't + seem to work for this because EGCS 1.0.3 on i686-Linux without -O won't + allow it to be used as an initializer). */ +#define XTENSA_UNDEFINED -1 + + +typedef int libisa_module_specifier; + +extern xtensa_isa xtensa_isa_init (void); + + +/* Instruction buffers. */ + +typedef uint32 xtensa_insnbuf_word; +typedef xtensa_insnbuf_word *xtensa_insnbuf; + +/* Get the size in words of the xtensa_insnbuf array. */ +extern int xtensa_insnbuf_size (xtensa_isa); + +/* Allocate (with malloc) an xtensa_insnbuf of the right size. */ +extern xtensa_insnbuf xtensa_insnbuf_alloc (xtensa_isa); + +/* Release (with free) an xtensa_insnbuf of the right size. */ +extern void xtensa_insnbuf_free (xtensa_insnbuf); + +/* Inward and outward conversion from memory images (byte streams) to our + internal instruction representation. */ +extern void xtensa_insnbuf_to_chars (xtensa_isa, const xtensa_insnbuf, + char *); + +extern void xtensa_insnbuf_from_chars (xtensa_isa, xtensa_insnbuf, + const char *); + + +/* ISA information. */ + +/* Load the ISA information from a shared library. If successful, this returns + a value which identifies the ISA for use in subsequent calls to the ISA + library; otherwise, it returns NULL. Multiple ISAs can be loaded to support + heterogeneous multiprocessor systems. */ +extern xtensa_isa xtensa_load_isa (libisa_module_specifier); + +/* Extend an existing set of ISA information by loading an additional shared + library of ISA information. This is primarily intended for loading TIE + extensions. If successful, the return value is non-zero. */ +extern int xtensa_extend_isa (xtensa_isa, libisa_module_specifier); + +/* The default ISA. This variable is set automatically to the ISA most + recently loaded and is provided as a convenience. An exception is the GNU + opcodes library, where there is a fixed interface that does not allow + passing the ISA as a parameter and the ISA must be taken from this global + variable. (Note: Since this variable is just a convenience, it is not + exported when libisa is built as a DLL, due to the hassle of dealing with + declspecs.) */ +extern xtensa_isa xtensa_default_isa; + + +/* Deallocate an xtensa_isa structure. */ +extern void xtensa_isa_free (xtensa_isa); + +/* Get the maximum instruction size in bytes. */ +extern int xtensa_insn_maxlength (xtensa_isa); + +/* Get the total number of opcodes for this processor. */ +extern int xtensa_num_opcodes (xtensa_isa); + +/* 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, const char *); + +/* Decode a binary instruction buffer. Returns the opcode or + XTENSA_UNDEFINED if the instruction is illegal. */ +extern xtensa_opcode xtensa_decode_insn (xtensa_isa, const xtensa_insnbuf); + + +/* Opcode information. */ + +/* Set the opcode field(s) in a binary instruction buffer. The operand + fields are set to zero. */ +extern void xtensa_encode_insn (xtensa_isa, xtensa_opcode, xtensa_insnbuf); + +/* Get the mnemonic name for an opcode. */ +extern const char * xtensa_opcode_name (xtensa_isa, xtensa_opcode); + +/* Find the length (in bytes) of an instruction. */ +extern int xtensa_insn_length (xtensa_isa, xtensa_opcode); + +/* Find the length of an instruction by looking only at the first byte. */ +extern int xtensa_insn_length_from_first_byte (xtensa_isa, char); + +/* Find the number of operands for an instruction. */ +extern int xtensa_num_operands (xtensa_isa, xtensa_opcode); + +/* Get the information about operand number "opnd" of a particular opcode. */ +extern xtensa_operand xtensa_get_operand (xtensa_isa, xtensa_opcode, int); + +/* Operand information. */ + +/* Find the kind of operand. There are three possibilities: + 1) PC-relative immediates (e.g., "l", "L"). These can be identified with + the xtensa_operand_isPCRelative function. + 2) non-PC-relative immediates ("i"). + 3) register-file short names (e.g., "a", "b", "m" and others defined + via TIE). */ +extern char * xtensa_operand_kind (xtensa_operand); + +/* Check if an operand is an input ('<'), output ('>'), or inout ('=') + operand. Note: The output operand of a conditional assignment + (e.g., movnez) appears here as an inout ('=') even if it is declared + in the TIE code as an output ('>'); this allows the compiler to + properly handle register allocation for conditional assignments. */ +extern char xtensa_operand_inout (xtensa_operand); + +/* 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. */ +extern uint32 xtensa_operand_get_field (xtensa_operand, const xtensa_insnbuf); + +extern void xtensa_operand_set_field (xtensa_operand, xtensa_insnbuf, uint32); + + +/* 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 encode function has a special return type + (xtensa_encode_result) to indicate success or the reason for failure; the + encoded value is returned through the argument pointer. The decode function + has no possibility of failure and returns the decoded value. */ + +typedef enum +{ + xtensa_encode_result_ok, + xtensa_encode_result_align, + xtensa_encode_result_not_in_table, + xtensa_encode_result_too_low, + xtensa_encode_result_too_high, + xtensa_encode_result_not_ok, + xtensa_encode_result_max = xtensa_encode_result_not_ok +} xtensa_encode_result; + +extern xtensa_encode_result xtensa_operand_encode (xtensa_operand, uint32 *); + +extern uint32 xtensa_operand_decode (xtensa_operand, uint32); + + +/* 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 first function + takes the desired address and the PC of the current instruction and returns + the unencoded value to be stored in the offset field. The second function + takes the unencoded offset value and the current PC and returns the address. + Note that these functions do not replace the encode/decode functions; the + operands must be encoded/decoded separately. */ + +extern int xtensa_operand_isPCRelative (xtensa_operand); + +extern uint32 xtensa_operand_do_reloc (xtensa_operand, uint32, uint32); + +extern uint32 xtensa_operand_undo_reloc (xtensa_operand, uint32, uint32); + +#ifdef __cplusplus +} +#endif +#endif /* XTENSA_LIBISA_H */ |