/***************************************************************************

    mips3fe.c

    Front-end for MIPS3 recompiler

    Copyright (c) 2007, Aaron Giles
    Released for general use under the MAME license
    Visit http://mamedev.org for licensing and usage restrictions.

***************************************************************************/

#include <stddef.h>
#include "cpuintrf.h"
#include "mips3fe.h"
#include "mips3com.h"


/***************************************************************************
    FUNCTION PROTOTYPES
***************************************************************************/

static int describe_instruction_special(mips3_state *mips, UINT32 op, opcode_desc *desc);
static int describe_instruction_regimm(mips3_state *mips, UINT32 op, opcode_desc *desc);
static int describe_instruction_idt(mips3_state *mips, UINT32 op, opcode_desc *desc);
static int describe_instruction_cop0(mips3_state *mips, UINT32 op, opcode_desc *desc);
static int describe_instruction_cop1(mips3_state *mips, UINT32 op, opcode_desc *desc);
static int describe_instruction_cop1x(mips3_state *mips, UINT32 op, opcode_desc *desc);
static int describe_instruction_cop2(mips3_state *mips, UINT32 op, opcode_desc *desc);



/***************************************************************************
    INSTRUCTION PARSERS
***************************************************************************/

/*-------------------------------------------------
    describe_instruction - build a description
    of a single instruction
-------------------------------------------------*/

int mips3fe_describe(void *param, opcode_desc *desc)
{
	mips3_state *mips = param;
	UINT32 op = *desc->opptr.l;
	UINT8 opswitch = op >> 26;

	/* all instructions are 4 bytes and default to a single cycle each */
	desc->length = 4;
	desc->cycles = 1;

	/* parse the instruction */
	switch (opswitch)
	{
		case 0x00:	/* SPECIAL */
			return describe_instruction_special(mips, op, desc);

		case 0x01:	/* REGIMM */
			return describe_instruction_regimm(mips, op, desc);

		case 0x10:	/* COP0 */
			return describe_instruction_cop0(mips, op, desc);

		case 0x11:	/* COP1 */
			return describe_instruction_cop1(mips, op, desc);

		case 0x12:	/* COP2 */
			return describe_instruction_cop2(mips, op, desc);

		case 0x13:	/* COP1X - MIPS IV */
			if (mips->flavor < MIPS3_TYPE_MIPS_IV)
				return FALSE;
			return describe_instruction_cop1x(mips, op, desc);

		case 0x1c:	/* IDT-specific opcodes: mad/madu/mul on R4640/4650, msub on RC32364 */
			return describe_instruction_idt(mips, op, desc);

		case 0x02:	/* J */
			desc->flags |= OPFLAG_IS_UNCONDITIONAL_BRANCH | OPFLAG_END_SEQUENCE;
			desc->targetpc = (desc->pc & 0xf0000000) | (LIMMVAL << 2);
			desc->delayslots = 1;
			return TRUE;

		case 0x03:	/* JAL */
			desc->gpr.modified |= REGFLAG_R(31);
			desc->flags |= OPFLAG_IS_UNCONDITIONAL_BRANCH | OPFLAG_END_SEQUENCE;
			desc->targetpc = (desc->pc & 0xf0000000) | (LIMMVAL << 2);
			desc->delayslots = 1;
			return TRUE;

		case 0x04:	/* BEQ */
		case 0x05:	/* BNE */
		case 0x14:	/* BEQL */
		case 0x15:	/* BNEL */
			if ((opswitch == 0x04 || opswitch == 0x14) && RSREG == RTREG)
				desc->flags |= OPFLAG_IS_UNCONDITIONAL_BRANCH | OPFLAG_END_SEQUENCE;
			else
			{
				desc->gpr.used |= REGFLAG_R(RSREG) | REGFLAG_R(RTREG);
				desc->flags |= OPFLAG_IS_CONDITIONAL_BRANCH;
			}
			desc->targetpc = desc->pc + 4 + (SIMMVAL << 2);
			desc->delayslots = 1;
			desc->skipslots = (opswitch & 0x10) ? 1 : 0;
			return TRUE;

		case 0x06:	/* BLEZ */
		case 0x07:	/* BGTZ */
		case 0x16:	/* BLEZL */
		case 0x17:	/* BGTZL */
			if ((opswitch == 0x06 || opswitch == 0x16) && RSREG == 0)
				desc->flags |= OPFLAG_IS_UNCONDITIONAL_BRANCH | OPFLAG_END_SEQUENCE;
			else
			{
				desc->gpr.used |= REGFLAG_R(RSREG);
				desc->flags |= OPFLAG_IS_CONDITIONAL_BRANCH;
			}
			desc->targetpc = desc->pc + 4 + (SIMMVAL << 2);
			desc->delayslots = 1;
			desc->skipslots = (opswitch & 0x10) ? 1 : 0;
			return TRUE;

		case 0x08:	/* ADDI */
		case 0x18:	/* DADDI */
			desc->gpr.used |= REGFLAG_R(RSREG);
			desc->gpr.modified |= REGFLAG_R(RTREG);
			desc->flags |= OPFLAG_CAN_CAUSE_EXCEPTION;
			return TRUE;

		case 0x09:	/* ADDIU */
		case 0x0a:	/* SLTI */
		case 0x0b:	/* SLTIU */
		case 0x0c:	/* ANDI */
		case 0x0d:	/* ORI */
		case 0x0e:	/* XORI */
		case 0x19:	/* DADDIU */
			desc->gpr.used |= REGFLAG_R(RSREG);
			desc->gpr.modified |= REGFLAG_R(RTREG);
			return TRUE;

		case 0x0f:	/* LUI */
			desc->gpr.modified |= REGFLAG_R(RTREG);
			return TRUE;

		case 0x1a:	/* LDL */
		case 0x1b:	/* LDR */
		case 0x22:	/* LWL */
		case 0x26:	/* LWR */
			desc->gpr.used |= REGFLAG_R(RTREG);
		case 0x20:	/* LB */
		case 0x21:	/* LH */
		case 0x23:	/* LW */
		case 0x24:	/* LBU */
		case 0x25:	/* LHU */
		case 0x27:	/* LWU */
		case 0x30:	/* LL */
		case 0x34:	/* LLD */
		case 0x37:	/* LD */
			desc->gpr.used |= REGFLAG_R(RSREG);
			desc->gpr.modified |= REGFLAG_R(RTREG);
			desc->flags |= OPFLAG_READS_MEMORY | OPFLAG_CAN_CAUSE_EXCEPTION;
			return TRUE;

		case 0x28:	/* SB */
		case 0x29:	/* SH */
		case 0x2a:	/* SWL */
		case 0x2b:	/* SW */
		case 0x2c:	/* SDL */
		case 0x2d:	/* SDR */
		case 0x2e:	/* SWR */
		case 0x38:	/* SC */
		case 0x3c:	/* SCD */
		case 0x3f:	/* SD */
			desc->gpr.used |= REGFLAG_R(RSREG) | REGFLAG_R(RTREG);
			desc->flags |= OPFLAG_WRITES_MEMORY | OPFLAG_CAN_CAUSE_EXCEPTION;
			return TRUE;

		case 0x31:	/* LWC1 */
		case 0x35:	/* LDC1 */
			desc->gpr.used |= REGFLAG_R(RSREG);
			desc->fpr.modified |= REGFLAG_CPR1(RTREG);
			desc->flags |= OPFLAG_READS_MEMORY | OPFLAG_CAN_CAUSE_EXCEPTION;
			return TRUE;

		case 0x39:	/* SWC1 */
		case 0x3d:	/* SDC1 */
			desc->gpr.used |= REGFLAG_R(RSREG);
			desc->fpr.used |= REGFLAG_CPR1(RTREG);
			desc->flags |= OPFLAG_WRITES_MEMORY | OPFLAG_CAN_CAUSE_EXCEPTION;
			return TRUE;

		case 0x32:	/* LWC2 */
		case 0x36:	/* LDC2 */
			desc->gpr.used |= REGFLAG_R(RSREG);
			desc->flags |= OPFLAG_READS_MEMORY | OPFLAG_CAN_CAUSE_EXCEPTION;
			return TRUE;

		case 0x3a:	/* SWC2 */
		case 0x3e:	/* SDC2 */
			desc->gpr.used |= REGFLAG_R(RSREG);
			desc->flags |= OPFLAG_WRITES_MEMORY | OPFLAG_CAN_CAUSE_EXCEPTION;
			return TRUE;

		case 0x33:	/* PREF */
			if (mips->flavor < MIPS3_TYPE_MIPS_IV)
				return FALSE;
		case 0x2f:	/* CACHE */
			/* effective no-op */
			return TRUE;
	}

	return FALSE;
}


/*-------------------------------------------------
    describe_instruction_special - build a
    description of a single instruction in the
    'special' group
-------------------------------------------------*/

static int describe_instruction_special(mips3_state *mips, UINT32 op, opcode_desc *desc)
{
	switch (op & 63)
	{
		case 0x00:	/* SLL */
		case 0x02:	/* SRL */
		case 0x03:	/* SRA */
		case 0x38:	/* DSLL */
		case 0x3a:	/* DSRL */
		case 0x3b:	/* DSRA */
		case 0x3c:	/* DSLL32 */
		case 0x3e:	/* DSRL32 */
		case 0x3f:	/* DSRA32 */
			desc->gpr.used |= REGFLAG_R(RTREG);
			desc->gpr.modified |= REGFLAG_R(RDREG);
			return TRUE;

		case 0x0a:	/* MOVZ - MIPS IV */
		case 0x0b:	/* MOVN - MIPS IV */
			if (mips->flavor < MIPS3_TYPE_MIPS_IV)
				return FALSE;
			desc->gpr.used |= REGFLAG_R(RDREG);
		case 0x04:	/* SLLV */
		case 0x06:	/* SRLV */
		case 0x07:	/* SRAV */
		case 0x14:	/* DSLLV */
		case 0x16:	/* DSRLV */
		case 0x17:	/* DSRAV */
		case 0x21:	/* ADDU */
		case 0x23:	/* SUBU */
		case 0x24:	/* AND */
		case 0x25:	/* OR */
		case 0x26:	/* XOR */
		case 0x27:	/* NOR */
		case 0x2a:	/* SLT */
		case 0x2b:	/* SLTU */
		case 0x2d:	/* DADDU */
		case 0x2f:	/* DSUBU */
			desc->gpr.used |= REGFLAG_R(RSREG) | REGFLAG_R(RTREG);
			desc->gpr.modified |= REGFLAG_R(RDREG);
			return TRUE;

		case 0x20:	/* ADD */
		case 0x22:	/* SUB */
		case 0x2c:	/* DADD */
		case 0x2e:	/* DSUB */
			desc->gpr.used |= REGFLAG_R(RSREG) | REGFLAG_R(RTREG);
			desc->gpr.modified |= REGFLAG_R(RDREG);
			desc->flags |= OPFLAG_CAN_CAUSE_EXCEPTION;
			return TRUE;

		case 0x30:	/* TGE */
		case 0x31:	/* TGEU */
		case 0x32:	/* TLT */
		case 0x33:	/* TLTU */
		case 0x34:	/* TEQ */
		case 0x36:	/* TNE */
			desc->gpr.used |= REGFLAG_R(RSREG) | REGFLAG_R(RTREG);
			desc->flags |= OPFLAG_CAN_CAUSE_EXCEPTION;
			return TRUE;

		case 0x01:	/* MOVF - MIPS IV */
			if (mips->flavor < MIPS3_TYPE_MIPS_IV)
				return FALSE;
			desc->gpr.used |= REGFLAG_R(RSREG);
			desc->fpr.used |= REGFLAG_FCC;
			desc->gpr.modified |= REGFLAG_R(RDREG);
			return TRUE;

		case 0x08:	/* JR */
			desc->gpr.used |= REGFLAG_R(RSREG);
			desc->flags |= OPFLAG_IS_UNCONDITIONAL_BRANCH | OPFLAG_END_SEQUENCE;
			desc->delayslots = 1;
			return TRUE;

		case 0x09:	/* JALR */
			desc->gpr.used |= REGFLAG_R(RSREG);
			desc->gpr.modified |= REGFLAG_R(RDREG);
			desc->flags |= OPFLAG_IS_UNCONDITIONAL_BRANCH | OPFLAG_END_SEQUENCE;
			desc->delayslots = 1;
			return TRUE;

		case 0x10:	/* MFHI */
			desc->gpr.used |= REGFLAG_HI;
			desc->gpr.modified |= REGFLAG_R(RDREG);
			return TRUE;

		case 0x11:	/* MTHI */
			desc->gpr.used |= REGFLAG_R(RSREG);
			desc->gpr.modified |= REGFLAG_HI;
			return TRUE;

		case 0x12:	/* MFLO */
			desc->gpr.used |= REGFLAG_LO;
			desc->gpr.modified |= REGFLAG_R(RDREG);
			return TRUE;

		case 0x13:	/* MTLO */
			desc->gpr.used |= REGFLAG_R(RSREG);
			desc->gpr.modified |= REGFLAG_LO;
			return TRUE;

		case 0x18:	/* MULT */
		case 0x19:	/* MULTU */
			desc->gpr.used |= REGFLAG_R(RSREG) | REGFLAG_R(RTREG);
			desc->gpr.modified |= REGFLAG_LO | REGFLAG_HI;
			desc->cycles = 3;
			return TRUE;

		case 0x1a:	/* DIV */
		case 0x1b:	/* DIVU */
			desc->gpr.used |= REGFLAG_R(RSREG) | REGFLAG_R(RTREG);
			desc->gpr.modified |= REGFLAG_LO | REGFLAG_HI;
			desc->cycles = 35;
			return TRUE;

		case 0x1c:	/* DMULT */
		case 0x1d:	/* DMULTU */
			desc->gpr.used |= REGFLAG_R(RSREG) | REGFLAG_R(RTREG);
			desc->gpr.modified |= REGFLAG_LO | REGFLAG_HI;
			desc->cycles = 7;
			return TRUE;

		case 0x1e:	/* DDIV */
		case 0x1f:	/* DDIVU */
			desc->gpr.used |= REGFLAG_R(RSREG) | REGFLAG_R(RTREG);
			desc->gpr.modified |= REGFLAG_LO | REGFLAG_HI;
			desc->cycles = 67;
			return TRUE;

		case 0x0c:	/* SYSCALL */
		case 0x0d:	/* BREAK */
			desc->flags |= OPFLAG_WILL_CAUSE_EXCEPTION | OPFLAG_END_SEQUENCE;
			return TRUE;

		case 0x0f:	/* SYNC */
			/* effective no-op */
			return TRUE;
	}

	return FALSE;
}


/*-------------------------------------------------
    describe_instruction_regimm - build a
    description of a single instruction in the
    'regimm' group
-------------------------------------------------*/

static int describe_instruction_regimm(mips3_state *mips, UINT32 op, opcode_desc *desc)
{
	switch (RTREG)
	{
		case 0x00:	/* BLTZ */
		case 0x01:	/* BGEZ */
		case 0x02:	/* BLTZL */
		case 0x03:	/* BGEZL */
			if (RTREG == 0x01 && RSREG == 0)
				desc->flags |= OPFLAG_IS_UNCONDITIONAL_BRANCH | OPFLAG_END_SEQUENCE;
			else
			{
				desc->gpr.used |= REGFLAG_R(RSREG);
				desc->flags |= OPFLAG_IS_CONDITIONAL_BRANCH;
			}
			desc->targetpc = desc->pc + 4 + (SIMMVAL << 2);
			desc->delayslots = 1;
			desc->skipslots = (RTREG & 0x02) ? 1 : 0;
			return TRUE;

		case 0x08:	/* TGEI */
		case 0x09:	/* TGEIU */
		case 0x0a:	/* TLTI */
		case 0x0b:	/* TLTIU */
		case 0x0c:	/* TEQI */
		case 0x0e:	/* TNEI */
			desc->gpr.used |= REGFLAG_R(RSREG);
			desc->flags |= OPFLAG_CAN_CAUSE_EXCEPTION;
			return TRUE;

		case 0x10:	/* BLTZAL */
		case 0x11:	/* BGEZAL */
		case 0x12:	/* BLTZALL */
		case 0x13:	/* BGEZALL */
			if (RTREG == 0x11 && RSREG == 0)
				desc->flags |= OPFLAG_IS_UNCONDITIONAL_BRANCH | OPFLAG_END_SEQUENCE;
			else
			{
				desc->gpr.used |= REGFLAG_R(RSREG);
				desc->flags |= OPFLAG_IS_CONDITIONAL_BRANCH;
			}
			desc->gpr.modified |= REGFLAG_R(31);
			desc->targetpc = desc->pc + 4 + (SIMMVAL << 2);
			desc->delayslots = 1;
			desc->skipslots = (RTREG & 0x02) ? 1 : 0;
			return TRUE;
	}

	return FALSE;
}


/*-------------------------------------------------
    describe_instruction_idt - build a
    description of a single instruction in the
    IDT-specific group
-------------------------------------------------*/

static int describe_instruction_idt(mips3_state *mips, UINT32 op, opcode_desc *desc)
{
	switch (op & 0x1f)
	{
		case 0: /* MAD */
		case 1: /* MADU */
			desc->gpr.used |= REGFLAG_R(RSREG) | REGFLAG_R(RTREG) | REGFLAG_LO | REGFLAG_HI;
			desc->gpr.modified |= REGFLAG_LO | REGFLAG_HI;
			return TRUE;

		case 2: /* MUL */
			desc->gpr.used |= REGFLAG_R(RSREG) | REGFLAG_R(RTREG);
			desc->gpr.modified |= REGFLAG_R(RDREG);
			desc->cycles = 3;
			return TRUE;
	}

	return FALSE;
}


/*-------------------------------------------------
    describe_instruction_cop0 - build a
    description of a single instruction in the
    COP0 group
-------------------------------------------------*/

static int describe_instruction_cop0(mips3_state *mips, UINT32 op, opcode_desc *desc)
{
	/* any COP0 instruction can potentially cause an exception */
	desc->flags |= OPFLAG_CAN_CAUSE_EXCEPTION;

	switch (RSREG)
	{
		case 0x00:	/* MFCz */
		case 0x01:	/* DMFCz */
		case 0x02:	/* CFCz */
			desc->gpr.modified |= REGFLAG_R(RTREG);
			return TRUE;

		case 0x04:	/* MTCz */
		case 0x05:	/* DMTCz */
		case 0x06:	/* CTCz */
			desc->gpr.used |= REGFLAG_R(RTREG);
			if (RSREG == 0x04 || RSREG == 0x05)
			{
				if (RDREG == COP0_Cause)
					desc->flags |= OPFLAG_CAN_TRIGGER_SW_INT;
				if (RDREG == COP0_Status)
					desc->flags |= OPFLAG_CAN_EXPOSE_EXTERNAL_INT | OPFLAG_CAN_CHANGE_MODES | OPFLAG_END_SEQUENCE;
			}
			return TRUE;

		case 0x08:	/* BC */
			switch (RTREG)
			{
				case 0x00:	/* BCzF */
				case 0x01:	/* BCzT */
					desc->flags |= OPFLAG_IS_CONDITIONAL_BRANCH;
					desc->targetpc = desc->pc + 4 + (SIMMVAL << 2);
					desc->delayslots = 1;
					return TRUE;
			}
			return FALSE;

		case 0x10:	case 0x11:	case 0x12:	case 0x13:	case 0x14:	case 0x15:	case 0x16:	case 0x17:
		case 0x18:	case 0x19:	case 0x1a:	case 0x1b:	case 0x1c:	case 0x1d:	case 0x1e:	case 0x1f:	/* COP */
			switch (op & 0x01ffffff)
			{
				case 0x01:	/* TLBR */
				case 0x08:	/* TLBP */
				case 0x20:	/* WAIT */
					return TRUE;

				case 0x02:	/* TLBWI */
				case 0x06:	/* TLBWR */
					desc->flags |= OPFLAG_MODIFIES_TRANSLATION;
					return TRUE;

				case 0x18:	/* ERET */
					desc->flags |= OPFLAG_IS_UNCONDITIONAL_BRANCH | OPFLAG_END_SEQUENCE;
					return TRUE;
			}
			return FALSE;
	}

	return FALSE;
}


/*-------------------------------------------------
    describe_instruction_cop1 - build a
    description of a single instruction in the
    COP1 group
-------------------------------------------------*/

static int describe_instruction_cop1(mips3_state *mips, UINT32 op, opcode_desc *desc)
{
	/* any COP1 instruction can potentially cause an exception */
//  desc->flags |= OPFLAG_CAN_CAUSE_EXCEPTION;

	switch (RSREG)
	{
		case 0x00:	/* MFCz */
		case 0x01:	/* DMFCz */
			desc->fpr.used |= REGFLAG_CPR1(RDREG);
			desc->gpr.modified |= REGFLAG_R(RTREG);
			return TRUE;

		case 0x02:	/* CFCz */
			desc->gpr.modified |= REGFLAG_R(RTREG);
			return TRUE;

		case 0x04:	/* MTCz */
		case 0x05:	/* DMTCz */
			desc->gpr.used |= REGFLAG_R(RTREG);
			desc->fpr.modified |= REGFLAG_CPR1(RDREG);
			return TRUE;

		case 0x06:	/* CTCz */
			desc->gpr.used |= REGFLAG_R(RTREG);
			return TRUE;

		case 0x08:	/* BC */
			switch (RTREG & 3)
			{
				case 0x00:	/* BCzF */
				case 0x01:	/* BCzT */
				case 0x02:	/* BCzFL */
				case 0x03:	/* BCzTL */
					desc->fpr.used |= REGFLAG_FCC;
					desc->flags |= OPFLAG_IS_CONDITIONAL_BRANCH;
					desc->targetpc = desc->pc + 4 + (SIMMVAL << 2);
					desc->delayslots = 1;
					desc->skipslots = (RTREG & 0x02) ? 1 : 0;
					return TRUE;
			}
			return FALSE;

		case 0x10:	case 0x11:	case 0x12:	case 0x13:	case 0x14:	case 0x15:	case 0x16:	case 0x17:
		case 0x18:	case 0x19:	case 0x1a:	case 0x1b:	case 0x1c:	case 0x1d:	case 0x1e:	case 0x1f:	/* COP */
			switch (op & 0x3f)
			{
				case 0x12:	/* MOVZ - MIPS IV */
				case 0x13:	/* MOVN - MIPS IV */
					if (mips->flavor < MIPS3_TYPE_MIPS_IV)
						return FALSE;
				case 0x00:	/* ADD */
				case 0x01:	/* SUB */
				case 0x02:	/* MUL */
				case 0x03:	/* DIV */
					desc->fpr.used |= REGFLAG_CPR1(FSREG) | REGFLAG_CPR1(FTREG);
					desc->fpr.modified |= REGFLAG_CPR1(FDREG);
					return TRUE;

				case 0x15:	/* RECIP - MIPS IV */
				case 0x16:	/* RSQRT - MIPS IV */
					if (mips->flavor < MIPS3_TYPE_MIPS_IV)
						return FALSE;
				case 0x04:	/* SQRT */
				case 0x05:	/* ABS */
				case 0x06:	/* MOV */
				case 0x07:	/* NEG */
				case 0x08:	/* ROUND.L */
				case 0x09:	/* TRUNC.L */
				case 0x0a:	/* CEIL.L */
				case 0x0b:	/* FLOOR.L */
				case 0x0c:	/* ROUND.W */
				case 0x0d:	/* TRUNC.W */
				case 0x0e:	/* CEIL.W */
				case 0x0f:	/* FLOOR.W */
				case 0x20:	/* CVT.S */
				case 0x21:	/* CVT.D */
				case 0x24:	/* CVT.W */
				case 0x25:	/* CVT.L */
					desc->fpr.used |= REGFLAG_CPR1(FSREG);
					desc->fpr.modified |= REGFLAG_CPR1(FDREG);
					return TRUE;

				case 0x11:	/* MOVT/F - MIPS IV */
					if (mips->flavor < MIPS3_TYPE_MIPS_IV)
						return FALSE;
					desc->fpr.used |= REGFLAG_CPR1(FSREG) | REGFLAG_FCC;
					desc->fpr.modified |= REGFLAG_CPR1(FDREG);
					return TRUE;

				case 0x30:	case 0x38:	/* C.F */
				case 0x31:	case 0x39:	/* C.UN */
					desc->fpr.modified |= REGFLAG_FCC;
					return TRUE;

				case 0x32:	case 0x3a:	/* C.EQ */
				case 0x33:	case 0x3b:	/* C.UEQ */
				case 0x34:	case 0x3c:	/* C.OLT */
				case 0x35:	case 0x3d:	/* C.ULT */
				case 0x36:	case 0x3e:	/* C.OLE */
				case 0x37:	case 0x3f:	/* C.ULE */
					desc->fpr.used |= REGFLAG_CPR1(FSREG) | REGFLAG_CPR1(FTREG);
					desc->fpr.modified |= REGFLAG_FCC;
					return TRUE;
			}
			return FALSE;
	}

	return FALSE;
}


/*-------------------------------------------------
    describe_instruction_cop1x - build a
    description of a single instruction in the
    COP1X group
-------------------------------------------------*/

static int describe_instruction_cop1x(mips3_state *mips, UINT32 op, opcode_desc *desc)
{
	/* any COP1 instruction can potentially cause an exception */
//  desc->flags |= OPFLAG_CAN_CAUSE_EXCEPTION;

	switch (op & 0x3f)
	{
		case 0x00:	/* LWXC1 */
		case 0x01:	/* LDXC1 */
			desc->gpr.used |= REGFLAG_R(RSREG) | REGFLAG_R(RTREG);
			desc->fpr.modified |= REGFLAG_CPR1(FDREG);
			desc->flags |= OPFLAG_READS_MEMORY;
			return TRUE;

		case 0x08:	/* SWXC1 */
		case 0x09:	/* SDXC1 */
			desc->gpr.used |= REGFLAG_R(RSREG) | REGFLAG_R(RTREG);
			desc->fpr.used |= REGFLAG_CPR1(FDREG);
			desc->flags |= OPFLAG_WRITES_MEMORY;
			return TRUE;

		case 0x0f:	/* PREFX */
			/* effective no-op */
			return TRUE;

		case 0x20:	case 0x21:	/* MADD */
		case 0x28:	case 0x29:	/* MSUB */
		case 0x30:	case 0x31:	/* NMADD */
		case 0x38:	case 0x39:	/* NMSUB */
			desc->fpr.used |= REGFLAG_CPR1(FSREG) | REGFLAG_CPR1(FTREG) | REGFLAG_CPR1(FRREG);
			desc->fpr.modified |= REGFLAG_CPR1(FDREG);
			return TRUE;
	}

	return FALSE;
}


/*-------------------------------------------------
    describe_instruction_cop2 - build a
    description of a single instruction in the
    COP2 group
-------------------------------------------------*/

static int describe_instruction_cop2(mips3_state *mips, UINT32 op, opcode_desc *desc)
{
	/* any COP2 instruction can potentially cause an exception */
	desc->flags |= OPFLAG_CAN_CAUSE_EXCEPTION;

	switch (RSREG)
	{
		case 0x00:	/* MFCz */
		case 0x01:	/* DMFCz */
		case 0x02:	/* CFCz */
			desc->gpr.modified |= REGFLAG_R(RTREG);
			return TRUE;

		case 0x04:	/* MTCz */
		case 0x05:	/* DMTCz */
		case 0x06:	/* CTCz */
			desc->gpr.used |= REGFLAG_R(RTREG);
			return TRUE;

		case 0x08:	/* BC */
			switch (RTREG)
			{
				case 0x00:	/* BCzF */
				case 0x01:	/* BCzT */
					desc->flags |= OPFLAG_IS_CONDITIONAL_BRANCH;
					desc->targetpc = desc->pc + 4 + (SIMMVAL << 2);
					desc->delayslots = 1;
					return TRUE;
			}
			return FALSE;
	}

	return FALSE;
}
