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-rw-r--r--llvm/lib/Target/ARM/ARMCodeEmitter.cpp233
1 files changed, 175 insertions, 58 deletions
diff --git a/llvm/lib/Target/ARM/ARMCodeEmitter.cpp b/llvm/lib/Target/ARM/ARMCodeEmitter.cpp
index 6066671ff37..74dab5f1484 100644
--- a/llvm/lib/Target/ARM/ARMCodeEmitter.cpp
+++ b/llvm/lib/Target/ARM/ARMCodeEmitter.cpp
@@ -54,9 +54,9 @@ namespace {
}
void emitInstruction(const MachineInstr &MI);
- unsigned getBinaryCodeForInstr(const MachineInstr &MI);
int getMachineOpValue(const MachineInstr &MI, unsigned OpIndex);
unsigned getBaseOpcodeFor(const TargetInstrDescriptor *TID);
+ unsigned getBinaryCodeForInstr(const MachineInstr &MI);
void emitGlobalAddressForCall(GlobalValue *GV, bool DoesntNeedStub);
void emitExternalSymbolAddress(const char *ES, unsigned Reloc);
@@ -64,6 +64,8 @@ namespace {
int Disp = 0, unsigned PCAdj = 0 );
void emitJumpTableAddress(unsigned JTI, unsigned Reloc,
unsigned PCAdj = 0);
+ void emitGlobalConstant(const Constant *CV);
+ void emitMachineBasicBlock(MachineBasicBlock *BB);
private:
int getShiftOp(const MachineOperand &MO);
@@ -100,10 +102,13 @@ bool Emitter::runOnMachineFunction(MachineFunction &MF) {
return false;
}
+/// getBaseOpcodeFor - Return the opcode value
unsigned Emitter::getBaseOpcodeFor(const TargetInstrDescriptor *TID) {
return (TID->TSFlags & ARMII::OpcodeMask) >> ARMII::OpcodeShift;
}
+/// getShiftOp - Verify which is the shift opcode (bit[6:5]) of the
+/// machine operand.
int Emitter::getShiftOp(const MachineOperand &MO) {
unsigned ShiftOp = 0x0;
switch(ARM_AM::getAM2ShiftOpc(MO.getImmedValue())) {
@@ -133,20 +138,18 @@ int Emitter::getMachineOpValue(const MachineInstr &MI, unsigned OpIndex) {
rv = ARMRegisterInfo::getRegisterNumbering(MO.getReg());
} else if (MO.isImmediate()) {
rv = MO.getImmedValue();
- } else if (MO.isGlobalAddress() || MO.isExternalSymbol() ||
- MO.isConstantPoolIndex() || MO.isJumpTableIndex()) {
-
- if (MO.isGlobalAddress()) {
- emitGlobalAddressForCall(MO.getGlobal(), true);
- } else if (MO.isExternalSymbol()) {
- emitExternalSymbolAddress(MO.getSymbolName(), ARM::reloc_arm_relative);
- } else if (MO.isConstantPoolIndex()) {
- emitConstPoolAddress(MO.getConstantPoolIndex(), ARM::reloc_arm_relative);
- } else if (MO.isJumpTableIndex()) {
- emitJumpTableAddress(MO.getJumpTableIndex(), ARM::reloc_arm_relative);
- }
-
+ } else if (MO.isGlobalAddress()) {
+ emitGlobalAddressForCall(MO.getGlobal(), false);
+ } else if (MO.isExternalSymbol()) {
+ emitExternalSymbolAddress(MO.getSymbolName(), ARM::reloc_arm_relative);
+ } else if (MO.isConstantPoolIndex()) {
+ emitConstPoolAddress(MO.getConstantPoolIndex(), ARM::reloc_arm_relative);
+ } else if (MO.isJumpTableIndex()) {
+ emitJumpTableAddress(MO.getJumpTableIndex(), ARM::reloc_arm_relative);
+ } else if (MO.isMachineBasicBlock()) {
+ emitMachineBasicBlock(MO.getMachineBasicBlock());
}
+
return rv;
}
@@ -186,7 +189,11 @@ void Emitter::emitJumpTableAddress(unsigned JTI, unsigned Reloc,
Reloc, JTI, PCAdj));
}
-
+/// emitMachineBasicBlock - Emit the specified address basic block.
+void Emitter::emitMachineBasicBlock(MachineBasicBlock *BB) {
+ MCE.addRelocation(MachineRelocation::getBB(MCE.getCurrentPCOffset(),
+ ARM::reloc_arm_branch, BB));
+}
void Emitter::emitInstruction(const MachineInstr &MI) {
NumEmitted++; // Keep track of the # of mi's emitted
@@ -196,6 +203,7 @@ void Emitter::emitInstruction(const MachineInstr &MI) {
unsigned Emitter::getBinaryCodeForInstr(const MachineInstr &MI) {
const TargetInstrDescriptor *Desc = MI.getInstrDescriptor();
const unsigned opcode = MI.getOpcode();
+ // initial instruction mask
unsigned Value = 0xE0000000;
unsigned op;
@@ -204,10 +212,11 @@ unsigned Emitter::getBinaryCodeForInstr(const MachineInstr &MI) {
switch(Desc->TSFlags & ARMII::FormMask) {
default: {
assert(0 && "Unknown instruction subtype!");
+ // treat special instruction CLZ
if(opcode == ARM::CLZ) {
// set first operand
op = getMachineOpValue(MI,0);
- Value |= op << 12;
+ Value |= op << ARMII::RegRdShift;
// set second operand
op = getMachineOpValue(MI,1);
@@ -215,9 +224,51 @@ unsigned Emitter::getBinaryCodeForInstr(const MachineInstr &MI) {
}
break;
}
+ case ARMII::MulSMLAW:
+ case ARMII::MulSMULW:
+ // set bit W(21)
+ Value |= 1 << 21;
+ case ARMII::MulSMLA:
+ case ARMII::MulSMUL: {
+ // set bit W(21)
+ Value |= 1 << 24;
+
+ // set opcode (bit[7:4]). For more information, see ARM-ARM page A3-31
+ // SMLA<x><y> - 1yx0
+ // SMLAW<y> - 1y00
+ // SMULW<y> - 1y10
+ // SMUL<x><y> - 1yx0
+ unsigned char BaseOpcode = getBaseOpcodeFor(Desc);
+ Value |= BaseOpcode << 4;
+
+ unsigned Format = (Desc->TSFlags & ARMII::FormMask);
+ if (Format == ARMII::MulSMUL)
+ Value |= 1 << 22;
+
+ // set first operand
+ op = getMachineOpValue(MI,0);
+ Value |= op << ARMII::RegRnShift;
+
+ // set second operand
+ op = getMachineOpValue(MI,1);
+ Value |= op;
+
+ // set third operand
+ op = getMachineOpValue(MI,2);
+ Value |= op << ARMII::RegRsShift;
+
+ // instructions SMLA and SMLAW have a fourth operand
+ if (Format != ARMII::MulSMULW && Format != ARMII::MulSMUL) {
+ op = getMachineOpValue(MI,3);
+ Value |= op << ARMII::RegRdShift;
+ }
+
+ break;
+ }
case ARMII::MulFrm: {
+ // bit[7:4] is always 9
Value |= 9 << 4;
-
+ // set opcode (bit[23:20])
unsigned char BaseOpcode = getBaseOpcodeFor(Desc);
Value |= BaseOpcode << 20;
@@ -226,40 +277,53 @@ unsigned Emitter::getBinaryCodeForInstr(const MachineInstr &MI) {
// set first operand
op = getMachineOpValue(MI,0);
- Value |= op << (isMUL || isMLA ? 16 : 12);
+ Value |= op << (isMUL || isMLA ? ARMII::RegRnShift : ARMII::RegRdShift);
// set second operand
op = getMachineOpValue(MI,1);
- Value |= op << (isMUL || isMLA ? 0 : 16);
+ Value |= op << (isMUL || isMLA ? 0 : ARMII::RegRnShift);
// set third operand
op = getMachineOpValue(MI,2);
- Value |= op << (isMUL || isMLA ? 8 : 0);
+ Value |= op << (isMUL || isMLA ? ARMII::RegRsShift : 0);
+ // multiply instructions (except MUL), have a fourth operand
if (!isMUL) {
op = getMachineOpValue(MI,3);
- Value |= op << (isMLA ? 12 : 8);
+ Value |= op << (isMLA ? ARMII::RegRdShift : ARMII::RegRsShift);
}
break;
}
case ARMII::Branch: {
+ // set opcode (bit[27:24])
unsigned BaseOpcode = getBaseOpcodeFor(Desc);
Value |= BaseOpcode << 24;
+ // set signed_immed_24 field
op = getMachineOpValue(MI,0);
Value |= op;
+ // if it is a conditional branch, set cond field
+ if (opcode == ARM::Bcc) {
+ op = getMachineOpValue(MI,1);
+ Value &= 0x0FFFFFFF; // clear conditional field
+ Value |= op << 28; // set conditional field
+ }
+
break;
}
case ARMII::BranchMisc: {
+ // set opcode (bit[7:4])
unsigned char BaseOpcode = getBaseOpcodeFor(Desc);
Value |= BaseOpcode << 4;
+ // set bit[27:24] to 1, set bit[23:20] to 2 and set bit[19:8] to 0xFFF
Value |= 0x12fff << 8;
if (opcode == ARM::BX_RET)
- op = 0xe;
+ op = 0xe; // the return register is LR
else
+ // otherwise, set the return register
op = getMachineOpValue(MI,0);
Value |= op;
@@ -272,12 +336,15 @@ unsigned Emitter::getBinaryCodeForInstr(const MachineInstr &MI) {
break;
}
case ARMII::AddrMode1: {
+ // set opcode (bit[24:21]) of data-processing instructions
unsigned char BaseOpcode = getBaseOpcodeFor(Desc);
Value |= BaseOpcode << 21;
+ // treat 3 special instructions: MOVsra_flag, MOVsrl_flag and
+ // MOVrx.
unsigned Format = (Desc->TSFlags & ARMII::FormMask);
if (Format == ARMII::DPRdMisc) {
- Value |= getMachineOpValue(MI,0) << 12;
+ Value |= getMachineOpValue(MI,0) << ARMII::RegRdShift;
Value |= getMachineOpValue(MI,1);
switch(opcode) {
case ARM::MOVsra_flag: {
@@ -298,20 +365,26 @@ unsigned Emitter::getBinaryCodeForInstr(const MachineInstr &MI) {
break;
}
- bool IsDataProcessing3 = false;
-
- if (Format == ARMII::DPRImS || Format == ARMII::DPRRegS ||
- Format == ARMII::DPRSoRegS) {
- Value |= 1 << 20;
- IsDataProcessing3 = true;
- }
-
+ // Data processing operand instructions has 3 possible encodings (for more
+ // information, see ARM-ARM page A3-10):
+ // 1. <instr> <Rd>,<shifter_operand>
+ // 2. <instr> <Rn>,<shifter_operand>
+ // 3. <instr> <Rd>,<Rn>,<shifter_operand>
bool IsDataProcessing1 = Format == ARMII::DPRdIm ||
Format == ARMII::DPRdReg ||
Format == ARMII::DPRdSoReg;
bool IsDataProcessing2 = Format == ARMII::DPRnIm ||
Format == ARMII::DPRnReg ||
Format == ARMII::DPRnSoReg;
+ bool IsDataProcessing3 = false;
+
+ // set bit S(20)
+ if (Format == ARMII::DPRImS || Format == ARMII::DPRRegS ||
+ Format == ARMII::DPRSoRegS || IsDataProcessing2) {
+ Value |= 1 << ARMII::S_BitShift;
+ IsDataProcessing3 = !IsDataProcessing2;
+ }
+
IsDataProcessing3 = Format == ARMII::DPRIm ||
Format == ARMII::DPRReg ||
Format == ARMII::DPRSoReg ||
@@ -320,22 +393,24 @@ unsigned Emitter::getBinaryCodeForInstr(const MachineInstr &MI) {
// set first operand
op = getMachineOpValue(MI,0);
if (IsDataProcessing1 || IsDataProcessing3) {
- Value |= op << 12;
+ Value |= op << ARMII::RegRdShift;
} else if (IsDataProcessing2) {
- Value |= op << 16;
+ Value |= op << ARMII::RegRnShift;
}
+ // set second operand of data processing #3 instructions
if (IsDataProcessing3) {
op = getMachineOpValue(MI,1);
- Value |= op << 16;
+ Value |= op << ARMII::RegRnShift;
}
unsigned OperandIndex = IsDataProcessing3 ? 2 : 1;
- // set shift operand
switch (Format) {
case ARMII::DPRdIm: case ARMII::DPRnIm:
case ARMII::DPRIm: case ARMII::DPRImS: {
- Value |= 1 << 25;
+ // set bit I(25) to identify this is the immediate form of <shifter_op>
+ Value |= 1 << ARMII::I_BitShift;
+ // set immed_8 field
const MachineOperand &MO = MI.getOperand(OperandIndex);
op = ARM_AM::getSOImmVal(MO.getImmedValue());
Value |= op;
@@ -344,6 +419,7 @@ unsigned Emitter::getBinaryCodeForInstr(const MachineInstr &MI) {
}
case ARMII::DPRdReg: case ARMII::DPRnReg:
case ARMII::DPRReg: case ARMII::DPRRegS: {
+ // set last operand (register Rm)
op = getMachineOpValue(MI,OperandIndex);
Value |= op;
@@ -351,12 +427,20 @@ unsigned Emitter::getBinaryCodeForInstr(const MachineInstr &MI) {
}
case ARMII::DPRdSoReg: case ARMII::DPRnSoReg:
case ARMII::DPRSoReg: case ARMII::DPRSoRegS: {
+ // set last operand (register Rm)
op = getMachineOpValue(MI,OperandIndex);
Value |= op;
const MachineOperand &MO1 = MI.getOperand(OperandIndex + 1);
const MachineOperand &MO2 = MI.getOperand(OperandIndex + 2);
+ // identify it the instr is in immed or register shifts encoding
bool IsShiftByRegister = MO1.getReg() > 0;
+ // set shift operand (bit[6:4]).
+ // ASR - 101 if it is in register shifts encoding; 100, otherwise.
+ // LSL - 001 if it is in register shifts encoding; 000, otherwise.
+ // LSR - 011 if it is in register shifts encoding; 010, otherwise.
+ // ROR - 111 if it is in register shifts encoding; 110, otherwise.
+ // RRX - 110 and bit[11:7] clear.
switch(ARM_AM::getSORegShOp(MO2.getImmedValue())) {
default: assert(0 && "Unknown shift opc!");
case ARM_AM::asr: {
@@ -390,13 +474,16 @@ unsigned Emitter::getBinaryCodeForInstr(const MachineInstr &MI) {
break;
}
}
+ // set the field related to shift operations (except rrx).
if(ARM_AM::getSORegShOp(MO2.getImmedValue()) != ARM_AM::rrx)
if(IsShiftByRegister) {
+ // set the value of bit[11:8] (register Rs).
assert(MRegisterInfo::isPhysicalRegister(MO1.getReg()));
op = ARMRegisterInfo::getRegisterNumbering(MO1.getReg());
assert(ARM_AM::getSORegOffset(MO2.getImm()) == 0);
- Value |= op << 8;
+ Value |= op << ARMII::RegRsShift;
} else {
+ // set the value of bit [11:7] (shift_immed field).
op = ARM_AM::getSORegOffset(MO2.getImm());
Value |= op << 7;
}
@@ -409,83 +496,107 @@ unsigned Emitter::getBinaryCodeForInstr(const MachineInstr &MI) {
break;
}
case ARMII::AddrMode2: {
+ // bit 26 is always 1
Value |= 1 << 26;
unsigned Index = (Desc->TSFlags & ARMII::IndexModeMask);
+ // if the instruction uses offset addressing or pre-indexed addressing,
+ // set bit P(24) to 1
if (Index == ARMII::IndexModePre || Index == 0)
- Value |= 1 << 24;
+ Value |= 1 << ARMII::IndexShift;
+ // if the instruction uses post-indexed addressing, set bit W(21) to 1
if (Index == ARMII::IndexModePre)
Value |= 1 << 21;
unsigned Format = (Desc->TSFlags & ARMII::FormMask);
+ // If it is a load instruction (except LDRD), set bit L(20) to 1
if (Format == ARMII::LdFrm)
- Value |= 1 << 20;
+ Value |= 1 << ARMII::L_BitShift;
+ // set bit B(22)
unsigned BitByte = getBaseOpcodeFor(Desc);
Value |= BitByte << 22;
// set first operand
op = getMachineOpValue(MI,0);
- Value |= op << 12;
+ Value |= op << ARMII::RegRdShift;
- // addressing mode
+ // set second operand
op = getMachineOpValue(MI,1);
- Value |= op << 16;
+ Value |= op << ARMII::RegRnShift;
const MachineOperand &MO2 = MI.getOperand(2);
const MachineOperand &MO3 = MI.getOperand(3);
- Value |= (ARM_AM::getAM2Op(MO3.getImm()) == ARM_AM::add ? 1 : 0) << 23;
+ // set bit U(23) according to signal of immed value (positive or negative)
+ Value |= (ARM_AM::getAM2Op(MO3.getImm()) == ARM_AM::add ? 1 : 0) <<
+ ARMII::U_BitShift;
if (!MO2.getReg()) { // is immediate
if (ARM_AM::getAM2Offset(MO3.getImm()))
+ // set the value of offset_12 field
Value |= ARM_AM::getAM2Offset(MO3.getImm());
break;
}
- Value |= 1 << 25;
+ // set bit I(25), because this is not in immediate enconding.
+ Value |= 1 << ARMII::I_BitShift;
assert(MRegisterInfo::isPhysicalRegister(MO2.getReg()));
+ // set bit[3:0] to the corresponding Rm register
Value |= ARMRegisterInfo::getRegisterNumbering(MO2.getReg());
+ // if this instr is in scaled register offset/index instruction, set
+ // shift_immed(bit[11:7]) and shift(bit[6:5]) fields.
if (unsigned ShImm = ARM_AM::getAM2Offset(MO3.getImm())) {
unsigned ShiftOp = getShiftOp(MO3);
- Value |= ShiftOp << 5;
- Value |= ShImm << 7;
+ Value |= ShiftOp << 5; // shift
+ Value |= ShImm << 7; // shift_immed
}
break;
}
case ARMII::AddrMode3: {
+
unsigned Index = (Desc->TSFlags & ARMII::IndexModeMask);
+ // if the instruction uses offset addressing or pre-indexed addressing,
+ // set bit P(24) to 1
if (Index == ARMII::IndexModePre || Index == 0)
- Value |= 1 << 24;
+ Value |= 1 << ARMII::IndexShift;
unsigned Format = (Desc->TSFlags & ARMII::FormMask);
- if (Format == ARMII::LdFrm)
- Value |= 1 << 20;
+ // If it is a load instruction (except LDRD), set bit L(20) to 1
+ if (Format == ARMII::LdFrm && opcode != ARM::LDRD)
+ Value |= 1 << ARMII::L_BitShift;
+ // bit[7:4] is the opcode of this instruction class (bits S and H).
unsigned char BaseOpcode = getBaseOpcodeFor(Desc);
Value |= BaseOpcode << 4;
// set first operand
op = getMachineOpValue(MI,0);
- Value |= op << 12;
+ Value |= op << ARMII::RegRdShift;
- // addressing mode
+ // set second operand
op = getMachineOpValue(MI,1);
- Value |= op << 16;
+ Value |= op << ARMII::RegRnShift;
const MachineOperand &MO2 = MI.getOperand(2);
const MachineOperand &MO3 = MI.getOperand(3);
- Value |= (ARM_AM::getAM2Op(MO3.getImm()) == ARM_AM::add ? 1 : 0) << 23;
+ // set bit U(23) according to signal of immed value (positive or negative)
+ Value |= (ARM_AM::getAM2Op(MO3.getImm()) == ARM_AM::add ? 1 : 0) <<
+ ARMII::U_BitShift;
+ // if this instr is in register offset/index encoding, set bit[3:0]
+ // to the corresponding Rm register.
if (MO2.getReg()) {
Value |= ARMRegisterInfo::getRegisterNumbering(MO2.getReg());
break;
}
+ // if this instr is in immediate offset/index encoding, set bit 22 to 1
if (unsigned ImmOffs = ARM_AM::getAM3Offset(MO3.getImm())) {
Value |= 1 << 22;
+ // set operands
Value |= (ImmOffs >> 4) << 8; // immedH
Value |= (ImmOffs & ~0xF); // immedL
}
@@ -493,30 +604,36 @@ unsigned Emitter::getBinaryCodeForInstr(const MachineInstr &MI) {
break;
}
case ARMII::AddrMode4: {
+ // bit 27 is always 1
Value |= 1 << 27;
unsigned Format = (Desc->TSFlags & ARMII::FormMask);
+ // if it is a load instr, set bit L(20) to 1
if (Format == ARMII::LdFrm)
- Value |= 1 << 20;
+ Value |= 1 << ARMII::L_BitShift;
unsigned OpIndex = 0;
// set first operand
op = getMachineOpValue(MI,OpIndex);
- Value |= op << 16;
+ Value |= op << ARMII::RegRnShift;
- // set addressing mode
+ // set addressing mode by modifying bits U(23) and P(24)
+ // IA - Increment after - bit U = 1 and bit P = 0
+ // IB - Increment before - bit U = 1 and bit P = 1
+ // DA - Decrement after - bit U = 0 and bit P = 0
+ // DB - Decrement before - bit U = 0 and bit P = 1
const MachineOperand &MO = MI.getOperand(OpIndex + 1);
ARM_AM::AMSubMode Mode = ARM_AM::getAM4SubMode(MO.getImm());
switch(Mode) {
default: assert(0 && "Unknown addressing sub-mode!");
case ARM_AM::ia: Value |= 0x1 << 23; break;
- case ARM_AM::ib: Value |= 0x2 << 23; break;
+ case ARM_AM::ib: Value |= 0x3 << 23; break;
case ARM_AM::da: break;
case ARM_AM::db: Value |= 0x1 << 24; break;
}
- // set flag W
+ // set bit W(21)
if (ARM_AM::getAM4WBFlag(MO.getImm()))
Value |= 0x1 << 21;
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