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Reland "[mips][mt][6/7] Add support for mftr, mttr instructions.""
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Unlike many other instructions, these instructions have aliases which
take coprocessor registers, gpr register, accumulator (and dsp accumulator)
registers, floating point registers, floating point control registers and
coprocessor 2 data and control operands.

For the moment, these aliases are treated as pseudo instructions which are
expanded into the underlying instruction. As a result, disassembling these
instructions shows the underlying instruction and not the alias.

Reviewers: slthakur, atanasyan

Differential Revision: https://reviews.llvm.org/D35253

The last version of this patch broke one of the expensive checks buildbots,
this version changes the failing test/MC/Mips/mt/invalid.s and other invalid
tests to write the errors to a file and run FileCheck on that, rather than
relying on the 'not llvm-mc ... <%s 2>&1 | Filecheck %s' idiom.

Hopefully this will sarisfy the buildbot.

llvm-svn: 308023
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Simon Dardis committed Jul 14, 2017
1 parent 5aae773 commit b352984
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Showing 16 changed files with 573 additions and 27 deletions.
219 changes: 219 additions & 0 deletions llvm/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
View file
Expand Up @@ -304,6 +304,9 @@ class MipsAsmParser : public MCTargetAsmParser {
bool expandSeqI(MCInst &Inst, SMLoc IDLoc, MCStreamer &Out,
const MCSubtargetInfo *STI);

bool expandMXTRAlias(MCInst &Inst, SMLoc IDLoc, MCStreamer &Out,
const MCSubtargetInfo *STI);

bool reportParseError(Twine ErrorMsg);
bool reportParseError(SMLoc Loc, Twine ErrorMsg);

Expand Down Expand Up @@ -2511,6 +2514,16 @@ MipsAsmParser::tryExpandInstruction(MCInst &Inst, SMLoc IDLoc, MCStreamer &Out,
return expandSeq(Inst, IDLoc, Out, STI) ? MER_Fail : MER_Success;
case Mips::SEQIMacro:
return expandSeqI(Inst, IDLoc, Out, STI) ? MER_Fail : MER_Success;
case Mips::MFTC0: case Mips::MTTC0:
case Mips::MFTGPR: case Mips::MTTGPR:
case Mips::MFTLO: case Mips::MTTLO:
case Mips::MFTHI: case Mips::MTTHI:
case Mips::MFTACX: case Mips::MTTACX:
case Mips::MFTDSP: case Mips::MTTDSP:
case Mips::MFTC1: case Mips::MTTC1:
case Mips::MFTHC1: case Mips::MTTHC1:
case Mips::CFTC1: case Mips::CTTC1:
return expandMXTRAlias(Inst, IDLoc, Out, STI) ? MER_Fail : MER_Success;
}
}

Expand Down Expand Up @@ -4882,6 +4895,212 @@ bool MipsAsmParser::expandSeqI(MCInst &Inst, SMLoc IDLoc, MCStreamer &Out,
return false;
}

// Map the DSP accumulator and control register to the corresponding gpr
// operand. Unlike the other alias, the m(f|t)t(lo|hi|acx) instructions
// do not map the DSP registers contigously to gpr registers.
static unsigned getRegisterForMxtrDSP(MCInst &Inst, bool IsMFDSP) {
switch (Inst.getOpcode()) {
case Mips::MFTLO:
case Mips::MTTLO:
switch (Inst.getOperand(IsMFDSP ? 1 : 0).getReg()) {
case Mips::AC0:
return Mips::ZERO;
case Mips::AC1:
return Mips::A0;
case Mips::AC2:
return Mips::T0;
case Mips::AC3:
return Mips::T4;
default:
llvm_unreachable("Unknown register for 'mttr' alias!");
}
case Mips::MFTHI:
case Mips::MTTHI:
switch (Inst.getOperand(IsMFDSP ? 1 : 0).getReg()) {
case Mips::AC0:
return Mips::AT;
case Mips::AC1:
return Mips::A1;
case Mips::AC2:
return Mips::T1;
case Mips::AC3:
return Mips::T5;
default:
llvm_unreachable("Unknown register for 'mttr' alias!");
}
case Mips::MFTACX:
case Mips::MTTACX:
switch (Inst.getOperand(IsMFDSP ? 1 : 0).getReg()) {
case Mips::AC0:
return Mips::V0;
case Mips::AC1:
return Mips::A2;
case Mips::AC2:
return Mips::T2;
case Mips::AC3:
return Mips::T6;
default:
llvm_unreachable("Unknown register for 'mttr' alias!");
}
case Mips::MFTDSP:
case Mips::MTTDSP:
return Mips::S0;
default:
llvm_unreachable("Unknown instruction for 'mttr' dsp alias!");
}
}

// Map the floating point register operand to the corresponding register
// operand.
static unsigned getRegisterForMxtrFP(MCInst &Inst, bool IsMFTC1) {
switch (Inst.getOperand(IsMFTC1 ? 1 : 0).getReg()) {
case Mips::F0: return Mips::ZERO;
case Mips::F1: return Mips::AT;
case Mips::F2: return Mips::V0;
case Mips::F3: return Mips::V1;
case Mips::F4: return Mips::A0;
case Mips::F5: return Mips::A1;
case Mips::F6: return Mips::A2;
case Mips::F7: return Mips::A3;
case Mips::F8: return Mips::T0;
case Mips::F9: return Mips::T1;
case Mips::F10: return Mips::T2;
case Mips::F11: return Mips::T3;
case Mips::F12: return Mips::T4;
case Mips::F13: return Mips::T5;
case Mips::F14: return Mips::T6;
case Mips::F15: return Mips::T7;
case Mips::F16: return Mips::S0;
case Mips::F17: return Mips::S1;
case Mips::F18: return Mips::S2;
case Mips::F19: return Mips::S3;
case Mips::F20: return Mips::S4;
case Mips::F21: return Mips::S5;
case Mips::F22: return Mips::S6;
case Mips::F23: return Mips::S7;
case Mips::F24: return Mips::T8;
case Mips::F25: return Mips::T9;
case Mips::F26: return Mips::K0;
case Mips::F27: return Mips::K1;
case Mips::F28: return Mips::GP;
case Mips::F29: return Mips::SP;
case Mips::F30: return Mips::FP;
case Mips::F31: return Mips::RA;
default: llvm_unreachable("Unknown register for mttc1 alias!");
}
}

// Map the coprocessor operand the corresponding gpr register operand.
static unsigned getRegisterForMxtrC0(MCInst &Inst, bool IsMFTC0) {
switch (Inst.getOperand(IsMFTC0 ? 1 : 0).getReg()) {
case Mips::COP00: return Mips::ZERO;
case Mips::COP01: return Mips::AT;
case Mips::COP02: return Mips::V0;
case Mips::COP03: return Mips::V1;
case Mips::COP04: return Mips::A0;
case Mips::COP05: return Mips::A1;
case Mips::COP06: return Mips::A2;
case Mips::COP07: return Mips::A3;
case Mips::COP08: return Mips::T0;
case Mips::COP09: return Mips::T1;
case Mips::COP010: return Mips::T2;
case Mips::COP011: return Mips::T3;
case Mips::COP012: return Mips::T4;
case Mips::COP013: return Mips::T5;
case Mips::COP014: return Mips::T6;
case Mips::COP015: return Mips::T7;
case Mips::COP016: return Mips::S0;
case Mips::COP017: return Mips::S1;
case Mips::COP018: return Mips::S2;
case Mips::COP019: return Mips::S3;
case Mips::COP020: return Mips::S4;
case Mips::COP021: return Mips::S5;
case Mips::COP022: return Mips::S6;
case Mips::COP023: return Mips::S7;
case Mips::COP024: return Mips::T8;
case Mips::COP025: return Mips::T9;
case Mips::COP026: return Mips::K0;
case Mips::COP027: return Mips::K1;
case Mips::COP028: return Mips::GP;
case Mips::COP029: return Mips::SP;
case Mips::COP030: return Mips::FP;
case Mips::COP031: return Mips::RA;
default: llvm_unreachable("Unknown register for mttc0 alias!");
}
}

/// Expand an alias of 'mftr' or 'mttr' into the full instruction, by producing
/// an mftr or mttr with the correctly mapped gpr register, u, sel and h bits.
bool MipsAsmParser::expandMXTRAlias(MCInst &Inst, SMLoc IDLoc, MCStreamer &Out,
const MCSubtargetInfo *STI) {
MipsTargetStreamer &TOut = getTargetStreamer();
unsigned rd = 0;
unsigned u = 1;
unsigned sel = 0;
unsigned h = 0;
bool IsMFTR = false;
switch (Inst.getOpcode()) {
case Mips::MFTC0:
IsMFTR = true;
LLVM_FALLTHROUGH;
case Mips::MTTC0:
u = 0;
rd = getRegisterForMxtrC0(Inst, IsMFTR);
sel = Inst.getOperand(2).getImm();
break;
case Mips::MFTGPR:
IsMFTR = true;
LLVM_FALLTHROUGH;
case Mips::MTTGPR:
rd = Inst.getOperand(IsMFTR ? 1 : 0).getReg();
break;
case Mips::MFTLO:
case Mips::MFTHI:
case Mips::MFTACX:
case Mips::MFTDSP:
IsMFTR = true;
LLVM_FALLTHROUGH;
case Mips::MTTLO:
case Mips::MTTHI:
case Mips::MTTACX:
case Mips::MTTDSP:
rd = getRegisterForMxtrDSP(Inst, IsMFTR);
sel = 1;
break;
case Mips::MFTHC1:
h = 1;
LLVM_FALLTHROUGH;
case Mips::MFTC1:
IsMFTR = true;
rd = getRegisterForMxtrFP(Inst, IsMFTR);
sel = 2;
break;
case Mips::MTTHC1:
h = 1;
LLVM_FALLTHROUGH;
case Mips::MTTC1:
rd = getRegisterForMxtrFP(Inst, IsMFTR);
sel = 2;
break;
case Mips::CFTC1:
IsMFTR = true;
LLVM_FALLTHROUGH;
case Mips::CTTC1:
rd = getRegisterForMxtrFP(Inst, IsMFTR);
sel = 3;
break;
}
unsigned Op0 = IsMFTR ? Inst.getOperand(0).getReg() : rd;
unsigned Op1 =
IsMFTR ? rd
: (Inst.getOpcode() != Mips::MTTDSP ? Inst.getOperand(1).getReg()
: Inst.getOperand(0).getReg());

TOut.emitRRIII(IsMFTR ? Mips::MFTR : Mips::MTTR, Op0, Op1, u, sel, h, IDLoc,
STI);
return false;
}

unsigned
MipsAsmParser::checkEarlyTargetMatchPredicate(MCInst &Inst,
const OperandVector &Operands) {
Expand Down
15 changes: 15 additions & 0 deletions llvm/lib/Target/Mips/MCTargetDesc/MipsTargetStreamer.cpp
View file
Expand Up @@ -193,6 +193,21 @@ void MipsTargetStreamer::emitRRI(unsigned Opcode, unsigned Reg0, unsigned Reg1,
emitRRX(Opcode, Reg0, Reg1, MCOperand::createImm(Imm), IDLoc, STI);
}

void MipsTargetStreamer::emitRRIII(unsigned Opcode, unsigned Reg0,
unsigned Reg1, int16_t Imm0, int16_t Imm1,
int16_t Imm2, SMLoc IDLoc,
const MCSubtargetInfo *STI) {
MCInst TmpInst;
TmpInst.setOpcode(Opcode);
TmpInst.addOperand(MCOperand::createReg(Reg0));
TmpInst.addOperand(MCOperand::createReg(Reg1));
TmpInst.addOperand(MCOperand::createImm(Imm0));
TmpInst.addOperand(MCOperand::createImm(Imm1));
TmpInst.addOperand(MCOperand::createImm(Imm2));
TmpInst.setLoc(IDLoc);
getStreamer().EmitInstruction(TmpInst, *STI);
}

void MipsTargetStreamer::emitAddu(unsigned DstReg, unsigned SrcReg,
unsigned TrgReg, bool Is64Bit,
const MCSubtargetInfo *STI) {
Expand Down
21 changes: 21 additions & 0 deletions llvm/lib/Target/Mips/MipsMTInstrFormats.td
View file
Expand Up @@ -35,6 +35,8 @@ class FIELD5<bits<5> Val> {
def FIELD5_1_DMT_EMT : FIELD5<0b00001>;
def FIELD5_2_DMT_EMT : FIELD5<0b01111>;
def FIELD5_1_2_DVPE_EVPE : FIELD5<0b00000>;
def FIELD5_MFTR : FIELD5<0b01000>;
def FIELD5_MTTR : FIELD5<0b01100>;

class COP0_MFMC0_MT<FIELD5 Op1, FIELD5 Op2, OPCODE1 sc> : MipsMTInst {
bits<32> Inst;
Expand All @@ -50,6 +52,25 @@ class COP0_MFMC0_MT<FIELD5 Op1, FIELD5 Op2, OPCODE1 sc> : MipsMTInst {
let Inst{2-0} = 0b001;
}

class COP0_MFTTR_MT<FIELD5 Op> : MipsMTInst {
bits<32> Inst;

bits<5> rt;
bits<5> rd;
bits<1> u;
bits<1> h;
bits<3> sel;
let Inst{31-26} = 0b010000; // COP0
let Inst{25-21} = Op.Value; // MFMC0
let Inst{20-16} = rt;
let Inst{15-11} = rd;
let Inst{10-6} = 0b00000; // rx - currently unsupported.
let Inst{5} = u;
let Inst{4} = h;
let Inst{3} = 0b0;
let Inst{2-0} = sel;
}

class SPECIAL3_MT_FORK : MipsMTInst {
bits<32> Inst;

Expand Down

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