bool mips3_frontend::describe(opcode_desc &desc, const opcode_desc *prev)
{
UINT32 op, opswitch;
// compute the physical PC
assert((desc.physpc & 3) == 0);
if (!mips3com_translate_address(&m_context, AS_PROGRAM, TRANSLATE_FETCH, &desc.physpc))
{
// uh-oh: a page fault; leave the description empty and just if this is the first instruction, leave it empty and
// mark as needing to validate; otherwise, just end the sequence here
desc.flags |= OPFLAG_VALIDATE_TLB | OPFLAG_CAN_CAUSE_EXCEPTION | OPFLAG_COMPILER_PAGE_FAULT | OPFLAG_VIRTUAL_NOOP | OPFLAG_END_SEQUENCE;
return true;
}
// fetch the opcode
assert((desc.physpc & 3) == 0);
op = desc.opptr.l[0] = m_context.direct->read_decrypted_dword(desc.physpc);
// all instructions are 4 bytes and default to a single cycle each
desc.length = 4;
desc.cycles = 1;
// parse the instruction
opswitch = op >> 26;
switch (opswitch)
{
case 0x00: // SPECIAL
return describe_special(op, desc);
case 0x01: // REGIMM
return describe_regimm(op, desc);
case 0x10: // COP0
return describe_cop0(op, desc);
case 0x11: // COP1
return describe_cop1(op, desc);
case 0x12: // COP2
return describe_cop2(op, desc);
case 0x13: // COP1X - MIPS IV
if (m_context.flavor < MIPS3_TYPE_MIPS_IV)
return false;
return describe_cop1x(op, desc);
case 0x1c: // IDT-specific opcodes: mad/madu/mul on R4640/4650, msub on RC32364
return describe_idt(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.regout[0] |= 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.regin[0] |= 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.regin[0] |= 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.regin[0] |= REGFLAG_R(RSREG);
desc.regout[0] |= 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.regin[0] |= REGFLAG_R(RSREG);
desc.regout[0] |= REGFLAG_R(RTREG);
return true;
case 0x0f: // LUI
desc.regout[0] |= REGFLAG_R(RTREG);
return true;
case 0x1a: // LDL
case 0x1b: // LDR
case 0x22: // LWL
case 0x26: // LWR
desc.regin[0] |= 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.regin[0] |= REGFLAG_R(RSREG);
desc.regout[0] |= 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 0x3f: // SD
desc.regin[0] |= REGFLAG_R(RSREG) | REGFLAG_R(RTREG);
desc.flags |= OPFLAG_WRITES_MEMORY | OPFLAG_CAN_CAUSE_EXCEPTION;
return true;
case 0x38: // SC
case 0x3c: // SCD
desc.regin[0] |= REGFLAG_R(RSREG) | REGFLAG_R(RTREG);
desc.regout[0] |= REGFLAG_R(RTREG);
desc.flags |= OPFLAG_WRITES_MEMORY | OPFLAG_CAN_CAUSE_EXCEPTION;
return true;
case 0x31: // LWC1
case 0x35: // LDC1
desc.regin[0] |= REGFLAG_R(RSREG);
desc.regout[1] |= REGFLAG_CPR1(RTREG);
desc.flags |= OPFLAG_READS_MEMORY | OPFLAG_CAN_CAUSE_EXCEPTION;
return true;
case 0x39: // SWC1
case 0x3d: // SDC1
desc.regin[0] |= REGFLAG_R(RSREG);
desc.regin[1] |= REGFLAG_CPR1(RTREG);
desc.flags |= OPFLAG_WRITES_MEMORY | OPFLAG_CAN_CAUSE_EXCEPTION;
return true;
case 0x32: // LWC2
case 0x36: // LDC2
desc.regin[0] |= REGFLAG_R(RSREG);
desc.flags |= OPFLAG_READS_MEMORY | OPFLAG_CAN_CAUSE_EXCEPTION;
return true;
case 0x3a: // SWC2
case 0x3e: // SDC2
desc.regin[0] |= REGFLAG_R(RSREG);
desc.flags |= OPFLAG_WRITES_MEMORY | OPFLAG_CAN_CAUSE_EXCEPTION;
return true;
case 0x33: // PREF
if (m_context.flavor < MIPS3_TYPE_MIPS_IV)
return false;
case 0x2f: // CACHE
// effective no-op
return true;
}
return false;
}
int mips3fe_describe(void *param, opcode_desc *desc, const opcode_desc *prev)
{
mips3_state *mipsaa = (mips3_state *)param;
UINT32 op, opswitch;
/* compute the physical PC */
if (!mips3com_translate_address(mipsaa, ADDRESS_SPACE_PROGRAM, TRANSLATE_FETCH, &desc->physpc))
{
/* uh-oh: a page fault; leave the description empty and just if this is the first instruction, leave it empty and */
/* mark as needing to validate; otherwise, just end the sequence here */
desc->flags |= OPFLAG_VALIDATE_TLB | OPFLAG_CAN_CAUSE_EXCEPTION | OPFLAG_COMPILER_PAGE_FAULT | OPFLAG_VIRTUAL_NOOP | OPFLAG_END_SEQUENCE;
return TRUE;
}
/* fetch the opcode */
op = desc->opptr.l[0] = memory_decrypted_read_dword(mipsaa->program, desc->physpc);
/* all instructions are 4 bytes and default to a single cycle each */
desc->length = 4;
desc->cycles = 1;
/* parse the instruction */
opswitch = op >> 26;
switch (opswitch)
{
case 0x00: /* SPECIAL */
return describe_instruction_special(mipsaa, op, desc);
case 0x01: /* REGIMM */
return describe_instruction_regimm(mipsaa, op, desc);
case 0x10: /* COP0 */
return describe_instruction_cop0(mipsaa, op, desc);
case 0x11: /* COP1 */
return describe_instruction_cop1(mipsaa, op, desc);
case 0x12: /* COP2 */
return describe_instruction_cop2(mipsaa, op, desc);
case 0x13: /* COP1X - MIPS IV */
if (mipsaa->flavor < MIPS3_TYPE_MIPS_IV)
return FALSE;
return describe_instruction_cop1x(mipsaa, op, desc);
case 0x1c: /* IDT-specific opcodes: mad/madu/mul on R4640/4650, msub on RC32364 */
return describe_instruction_idt(mipsaa, 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->regout[0] |= 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->regin[0] |= 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->regin[0] |= 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->regin[0] |= REGFLAG_R(RSREG);
desc->regout[0] |= 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->regin[0] |= REGFLAG_R(RSREG);
desc->regout[0] |= REGFLAG_R(RTREG);
return TRUE;
case 0x0f: /* LUI */
desc->regout[0] |= REGFLAG_R(RTREG);
return TRUE;
case 0x1a: /* LDL */
case 0x1b: /* LDR */
case 0x22: /* LWL */
case 0x26: /* LWR */
desc->regin[0] |= 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->regin[0] |= REGFLAG_R(RSREG);
desc->regout[0] |= 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 0x3f: /* SD */
desc->regin[0] |= REGFLAG_R(RSREG) | REGFLAG_R(RTREG);
desc->flags |= OPFLAG_WRITES_MEMORY | OPFLAG_CAN_CAUSE_EXCEPTION;
return TRUE;
case 0x38: /* SC */
case 0x3c: /* SCD */
desc->regin[0] |= REGFLAG_R(RSREG) | REGFLAG_R(RTREG);
desc->regout[0] |= REGFLAG_R(RTREG);
desc->flags |= OPFLAG_WRITES_MEMORY | OPFLAG_CAN_CAUSE_EXCEPTION;
return TRUE;
case 0x31: /* LWC1 */
case 0x35: /* LDC1 */
desc->regin[0] |= REGFLAG_R(RSREG);
desc->regout[1] |= REGFLAG_CPR1(RTREG);
desc->flags |= OPFLAG_READS_MEMORY | OPFLAG_CAN_CAUSE_EXCEPTION;
return TRUE;
case 0x39: /* SWC1 */
case 0x3d: /* SDC1 */
desc->regin[0] |= REGFLAG_R(RSREG);
desc->regin[1] |= REGFLAG_CPR1(RTREG);
desc->flags |= OPFLAG_WRITES_MEMORY | OPFLAG_CAN_CAUSE_EXCEPTION;
return TRUE;
case 0x32: /* LWC2 */
case 0x36: /* LDC2 */
desc->regin[0] |= REGFLAG_R(RSREG);
desc->flags |= OPFLAG_READS_MEMORY | OPFLAG_CAN_CAUSE_EXCEPTION;
return TRUE;
case 0x3a: /* SWC2 */
case 0x3e: /* SDC2 */
desc->regin[0] |= REGFLAG_R(RSREG);
desc->flags |= OPFLAG_WRITES_MEMORY | OPFLAG_CAN_CAUSE_EXCEPTION;
return TRUE;
case 0x33: /* PREF */
if (mipsaa->flavor < MIPS3_TYPE_MIPS_IV)
return FALSE;
case 0x2f: /* CACHE */
/* effective no-op */
return TRUE;
}
return FALSE;
}
