usr/src/sys/news3400/include/mips_opcode.h

/*-
 * Copyright (c) 1992 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Ralph Campbell.
 *
 * %sccs.include.redist.c%
 *
 *      @(#)mips_opcode.h       7.1 (Berkeley) %G%
 */

/*
 * Define the instruction formats and opcode values for the
 * MIPS instruction set.
 */

/*
 * Define the instruction formats.
 */
typedef union {
        unsigned word;

#if BYTE_ORDER == LITTLE_ENDIAN
        struct {
                unsigned imm: 16;
                unsigned rt: 5;
                unsigned rs: 5;
                unsigned op: 6;
        } IType;

        struct {
                unsigned target: 26;
                unsigned op: 6;
        } JType;

        struct {
                unsigned func: 6;
                unsigned shamt: 5;
                unsigned rd: 5;
                unsigned rt: 5;
                unsigned rs: 5;
                unsigned op: 6;
        } RType;

        struct {
                unsigned func: 6;
                unsigned fd: 5;
                unsigned fs: 5;
                unsigned ft: 5;
                unsigned fmt: 4;
                unsigned : 1;           /* always '1' */
                unsigned op: 6;         /* always '0x11' */
        } FRType;
#endif
#if BYTE_ORDER == BIG_ENDIAN
        struct {
                unsigned op: 6;
                unsigned rs: 5;
                unsigned rt: 5;
                unsigned imm: 16;
        } IType;

        struct {
                unsigned op: 6;
                unsigned target: 26;
        } JType;

        struct {
                unsigned op: 6;
                unsigned rs: 5;
                unsigned rt: 5;
                unsigned rd: 5;
                unsigned shamt: 5;
                unsigned func: 6;
        } RType;

        struct {
                unsigned op: 6;         /* always '0x11' */
                unsigned : 1;           /* always '1' */
                unsigned fmt: 4;
                unsigned ft: 5;
                unsigned fs: 5;
                unsigned fd: 5;
                unsigned func: 6;
        } FRType;
#endif
} InstFmt;

/*
 * Values for the 'op' field.
 */
#define OP_SPECIAL      000
#define OP_BCOND        001
#define OP_J            002
#define OP_JAL          003
#define OP_BEQ          004
#define OP_BNE          005
#define OP_BLEZ         006
#define OP_BGTZ         007

#define OP_ADDI         010
#define OP_ADDIU        011
#define OP_SLTI         012
#define OP_SLTIU        013
#define OP_ANDI         014
#define OP_ORI          015
#define OP_XORI         016
#define OP_LUI          017

#define OP_COP0         020
#define OP_COP1         021
#define OP_COP2         022
#define OP_COP3         023

#define OP_LB           040
#define OP_LH           041
#define OP_LWL          042
#define OP_LW           043
#define OP_LBU          044
#define OP_LHU          045
#define OP_LWR          046

#define OP_SB           050
#define OP_SH           051
#define OP_SWL          052
#define OP_SW           053
#define OP_SWR          056

#define OP_LWC0         060
#define OP_LWC1         061
#define OP_LWC2         062
#define OP_LWC3         063

#define OP_SWC0         070
#define OP_SWC1         071
#define OP_SWC2         072
#define OP_SWC3         073

/*
 * Values for the 'func' field when 'op' == OP_SPECIAL.
 */
#define OP_SLL          000
#define OP_SRL          002
#define OP_SRA          003
#define OP_SLLV         004
#define OP_SRLV         006
#define OP_SRAV         007

#define OP_JR           010
#define OP_JALR         011
#define OP_SYSCALL      014
#define OP_BREAK        015

#define OP_MFHI         020
#define OP_MTHI         021
#define OP_MFLO         022
#define OP_MTLO         023

#define OP_MULT         030
#define OP_MULTU        031
#define OP_DIV          032
#define OP_DIVU         033

#define OP_ADD          040
#define OP_ADDU         041
#define OP_SUB          042
#define OP_SUBU         043
#define OP_AND          044
#define OP_OR           045
#define OP_XOR          046
#define OP_NOR          047

#define OP_SLT          052
#define OP_SLTU         053

/*
 * Values for the 'func' field when 'op' == OP_BCOND.
 */
#define OP_BLTZ         000
#define OP_BGEZ         001
#define OP_BLTZAL       020
#define OP_BGEZAL       021

/*
 * Values for the 'rs' field when 'op' == OP_COPz.
 */
#define OP_MF           000
#define OP_MT           004
#define OP_BCx          010
#define OP_BCy          014
#define OP_CF           002
#define OP_CT           006

/*
 * Values for the 'rt' field when 'op' == OP_COPz.
 */
#define COPz_BC_TF_MASK 0x01
#define COPz_BC_TRUE    0x01
#define COPz_BC_FALSE   0x00