#include "CodeGenTarget.h"
#include "Record.h"
#include "llvm/ADT/StringExtras.h"
+#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
+#include <map>
using namespace llvm;
+// FIXME: Somewhat hackish to use a command line option for this. There should
+// be a CodeEmitter class in the Target.td that controls this sort of thing
+// instead.
+static cl::opt<bool>
+MCEmitter("mc-emitter",
+ cl::desc("Generate CodeEmitter for use with the MC library."),
+ cl::init(false));
+
void CodeEmitterGen::reverseBits(std::vector<Record*> &Insts) {
for (std::vector<Record*>::iterator I = Insts.begin(), E = Insts.end();
I != E; ++I) {
Record *R = *I;
- if (R->getValueAsString("Namespace") == "TargetOpcode")
+ if (R->getValueAsString("Namespace") == "TargetOpcode" ||
+ R->getValueAsBit("isPseudo"))
continue;
- BitsInit *BI = R->getValueAsBitsInit("Inst");
+ const BitsInit *BI = R->getValueAsBitsInit("Inst");
unsigned numBits = BI->getNumBits();
- BitsInit *NewBI = new BitsInit(numBits);
+
+ SmallVector<const Init *, 16> NewBits(numBits);
+
for (unsigned bit = 0, end = numBits / 2; bit != end; ++bit) {
unsigned bitSwapIdx = numBits - bit - 1;
- Init *OrigBit = BI->getBit(bit);
- Init *BitSwap = BI->getBit(bitSwapIdx);
- NewBI->setBit(bit, BitSwap);
- NewBI->setBit(bitSwapIdx, OrigBit);
+ const Init *OrigBit = BI->getBit(bit);
+ const Init *BitSwap = BI->getBit(bitSwapIdx);
+ NewBits[bit] = BitSwap;
+ NewBits[bitSwapIdx] = OrigBit;
}
if (numBits % 2) {
unsigned middle = (numBits + 1) / 2;
- NewBI->setBit(middle, BI->getBit(middle));
+ NewBits[middle] = BI->getBit(middle);
}
+ const BitsInit *NewBI = BitsInit::get(NewBits);
+
// Update the bits in reversed order so that emitInstrOpBits will get the
// correct endianness.
R->getValue("Inst")->setValue(NewBI);
}
}
-
// If the VarBitInit at position 'bit' matches the specified variable then
// return the variable bit position. Otherwise return -1.
int CodeEmitterGen::getVariableBit(const std::string &VarName,
- BitsInit *BI, int bit) {
- if (VarBitInit *VBI = dynamic_cast<VarBitInit*>(BI->getBit(bit))) {
- TypedInit *TI = VBI->getVariable();
-
- if (VarInit *VI = dynamic_cast<VarInit*>(TI)) {
- if (VI->getName() == VarName) return VBI->getBitNum();
- }
+ const BitsInit *BI, int bit) {
+ if (const VarBitInit *VBI = dynamic_cast<const VarBitInit*>(BI->getBit(bit))) {
+ if (const VarInit *VI = dynamic_cast<const VarInit*>(VBI->getVariable()))
+ if (VI->getName() == VarName)
+ return VBI->getBitNum();
+ } else if (const VarInit *VI = dynamic_cast<const VarInit*>(BI->getBit(bit))) {
+ if (VI->getName() == VarName)
+ return 0;
}
return -1;
}
+void CodeEmitterGen::
+AddCodeToMergeInOperand(Record *R, const BitsInit *BI, const std::string &VarName,
+ unsigned &NumberedOp,
+ std::string &Case, CodeGenTarget &Target) {
+ CodeGenInstruction &CGI = Target.getInstruction(R);
+
+ // Determine if VarName actually contributes to the Inst encoding.
+ int bit = BI->getNumBits()-1;
+
+ // Scan for a bit that this contributed to.
+ for (; bit >= 0; ) {
+ if (getVariableBit(VarName, BI, bit) != -1)
+ break;
+
+ --bit;
+ }
+
+ // If we found no bits, ignore this value, otherwise emit the call to get the
+ // operand encoding.
+ if (bit < 0) return;
+
+ // If the operand matches by name, reference according to that
+ // operand number. Non-matching operands are assumed to be in
+ // order.
+ unsigned OpIdx;
+ if (CGI.Operands.hasOperandNamed(VarName, OpIdx)) {
+ // Get the machine operand number for the indicated operand.
+ OpIdx = CGI.Operands[OpIdx].MIOperandNo;
+ assert(!CGI.Operands.isFlatOperandNotEmitted(OpIdx) &&
+ "Explicitly used operand also marked as not emitted!");
+ } else {
+ /// If this operand is not supposed to be emitted by the
+ /// generated emitter, skip it.
+ while (CGI.Operands.isFlatOperandNotEmitted(NumberedOp))
+ ++NumberedOp;
+ OpIdx = NumberedOp++;
+ }
+
+ std::pair<unsigned, unsigned> SO = CGI.Operands.getSubOperandNumber(OpIdx);
+ std::string &EncoderMethodName = CGI.Operands[SO.first].EncoderMethodName;
+
+ // If the source operand has a custom encoder, use it. This will
+ // get the encoding for all of the suboperands.
+ if (!EncoderMethodName.empty()) {
+ // A custom encoder has all of the information for the
+ // sub-operands, if there are more than one, so only
+ // query the encoder once per source operand.
+ if (SO.second == 0) {
+ Case += " // op: " + VarName + "\n" +
+ " op = " + EncoderMethodName + "(MI, " + utostr(OpIdx);
+ if (MCEmitter)
+ Case += ", Fixups";
+ Case += ");\n";
+ }
+ } else {
+ Case += " // op: " + VarName + "\n" +
+ " op = getMachineOpValue(MI, MI.getOperand(" + utostr(OpIdx) + ")";
+ if (MCEmitter)
+ Case += ", Fixups";
+ Case += ");\n";
+ }
+
+ for (; bit >= 0; ) {
+ int varBit = getVariableBit(VarName, BI, bit);
+
+ // If this bit isn't from a variable, skip it.
+ if (varBit == -1) {
+ --bit;
+ continue;
+ }
+
+ // Figure out the consecutive range of bits covered by this operand, in
+ // order to generate better encoding code.
+ int beginInstBit = bit;
+ int beginVarBit = varBit;
+ int N = 1;
+ for (--bit; bit >= 0;) {
+ varBit = getVariableBit(VarName, BI, bit);
+ if (varBit == -1 || varBit != (beginVarBit - N)) break;
+ ++N;
+ --bit;
+ }
+
+ unsigned opMask = ~0U >> (32-N);
+ int opShift = beginVarBit - N + 1;
+ opMask <<= opShift;
+ opShift = beginInstBit - beginVarBit;
+
+ if (opShift > 0) {
+ Case += " Value |= (op & " + utostr(opMask) + "U) << " +
+ itostr(opShift) + ";\n";
+ } else if (opShift < 0) {
+ Case += " Value |= (op & " + utostr(opMask) + "U) >> " +
+ itostr(-opShift) + ";\n";
+ } else {
+ Case += " Value |= op & " + utostr(opMask) + "U;\n";
+ }
+ }
+}
+
+
+std::string CodeEmitterGen::getInstructionCase(Record *R,
+ CodeGenTarget &Target) {
+ std::string Case;
+
+ const BitsInit *BI = R->getValueAsBitsInit("Inst");
+ const std::vector<RecordVal> &Vals = R->getValues();
+ unsigned NumberedOp = 0;
+
+ // Loop over all of the fields in the instruction, determining which are the
+ // operands to the instruction.
+ for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
+ // Ignore fixed fields in the record, we're looking for values like:
+ // bits<5> RST = { ?, ?, ?, ?, ? };
+ if (Vals[i].getPrefix() || Vals[i].getValue()->isComplete())
+ continue;
+
+ AddCodeToMergeInOperand(R, BI, Vals[i].getName(), NumberedOp, Case, Target);
+ }
+
+ std::string PostEmitter = R->getValueAsString("PostEncoderMethod");
+ if (!PostEmitter.empty())
+ Case += " Value = " + PostEmitter + "(MI, Value);\n";
+
+ return Case;
+}
void CodeEmitterGen::run(raw_ostream &o) {
- CodeGenTarget Target;
+ CodeGenTarget Target(Records);
std::vector<Record*> Insts = Records.getAllDerivedDefinitions("Instruction");
// For little-endian instruction bit encodings, reverse the bit order
if (Target.isLittleEndianEncoding()) reverseBits(Insts);
EmitSourceFileHeader("Machine Code Emitter", o);
- std::string Namespace = Insts[0]->getValueAsString("Namespace") + "::";
const std::vector<const CodeGenInstruction*> &NumberedInstructions =
Target.getInstructionsByEnumValue();
// Emit function declaration
- o << "unsigned " << Target.getName() << "CodeEmitter::"
- << "getBinaryCodeForInstr(const MachineInstr &MI) const {\n";
+ o << "unsigned " << Target.getName();
+ if (MCEmitter)
+ o << "MCCodeEmitter::getBinaryCodeForInstr(const MCInst &MI,\n"
+ << " SmallVectorImpl<MCFixup> &Fixups) const {\n";
+ else
+ o << "CodeEmitter::getBinaryCodeForInstr(const MachineInstr &MI) const {\n";
// Emit instruction base values
o << " static const unsigned InstBits[] = {\n";
const CodeGenInstruction *CGI = *IN;
Record *R = CGI->TheDef;
- if (R->getValueAsString("Namespace") == "TargetOpcode") {
+ if (R->getValueAsString("Namespace") == "TargetOpcode" ||
+ R->getValueAsBit("isPseudo")) {
o << " 0U,\n";
continue;
}
- BitsInit *BI = R->getValueAsBitsInit("Inst");
+ const BitsInit *BI = R->getValueAsBitsInit("Inst");
- // Start by filling in fixed values...
+ // Start by filling in fixed values.
unsigned Value = 0;
for (unsigned i = 0, e = BI->getNumBits(); i != e; ++i) {
- if (BitInit *B = dynamic_cast<BitInit*>(BI->getBit(e-i-1))) {
+ if (const BitInit *B = dynamic_cast<const BitInit*>(BI->getBit(e-i-1)))
Value |= B->getValue() << (e-i-1);
- }
}
o << " " << Value << "U," << '\t' << "// " << R->getName() << "\n";
}
for (std::vector<Record*>::iterator IC = Insts.begin(), EC = Insts.end();
IC != EC; ++IC) {
Record *R = *IC;
- if (R->getValueAsString("Namespace") == "TargetOpcode")
+ if (R->getValueAsString("Namespace") == "TargetOpcode" ||
+ R->getValueAsBit("isPseudo"))
continue;
- const std::string &InstName = R->getName();
- std::string Case("");
-
- BitsInit *BI = R->getValueAsBitsInit("Inst");
- const std::vector<RecordVal> &Vals = R->getValues();
- CodeGenInstruction &CGI = Target.getInstruction(R);
-
- // Loop over all of the fields in the instruction, determining which are the
- // operands to the instruction.
- unsigned NumberedOp = 0;
- for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
- if (!Vals[i].getPrefix() && !Vals[i].getValue()->isComplete()) {
- // Is the operand continuous? If so, we can just mask and OR it in
- // instead of doing it bit-by-bit, saving a lot in runtime cost.
- const std::string &VarName = Vals[i].getName();
- bool gotOp = false;
-
- for (int bit = BI->getNumBits()-1; bit >= 0; ) {
- int varBit = getVariableBit(VarName, BI, bit);
-
- if (varBit == -1) {
- --bit;
- } else {
- int beginInstBit = bit;
- int beginVarBit = varBit;
- int N = 1;
-
- for (--bit; bit >= 0;) {
- varBit = getVariableBit(VarName, BI, bit);
- if (varBit == -1 || varBit != (beginVarBit - N)) break;
- ++N;
- --bit;
- }
-
- if (!gotOp) {
- // If the operand matches by name, reference according to that
- // operand number. Non-matching operands are assumed to be in
- // order.
- unsigned OpIdx;
- if (CGI.hasOperandNamed(VarName, OpIdx)) {
- // Get the machine operand number for the indicated operand.
- OpIdx = CGI.OperandList[OpIdx].MIOperandNo;
- assert (!CGI.isFlatOperandNotEmitted(OpIdx) &&
- "Explicitly used operand also marked as not emitted!");
- } else {
- /// If this operand is not supposed to be emitted by the
- /// generated emitter, skip it.
- while (CGI.isFlatOperandNotEmitted(NumberedOp))
- ++NumberedOp;
- OpIdx = NumberedOp++;
- }
- std::pair<unsigned, unsigned> SO = CGI.getSubOperandNumber(OpIdx);
- std::string &EncoderMethodName =
- CGI.OperandList[SO.first].EncoderMethodName;
-
- // If the source operand has a custom encoder, use it. This will
- // get the encoding for all of the suboperands.
- if (!EncoderMethodName.empty()) {
- // A custom encoder has all of the information for the
- // sub-operands, if there are more than one, so only
- // query the encoder once per source operand.
- if (SO.second == 0) {
- Case += " // op: " + VarName + "\n"
- + " op = " + EncoderMethodName + "(MI, "
- + utostr(OpIdx) + ");\n";
- }
- } else {
- Case += " // op: " + VarName + "\n"
- + " op = getMachineOpValue(MI, MI.getOperand("
- + utostr(OpIdx) + "));\n";
- }
- gotOp = true;
- }
-
- unsigned opMask = ~0U >> (32-N);
- int opShift = beginVarBit - N + 1;
- opMask <<= opShift;
- opShift = beginInstBit - beginVarBit;
-
- if (opShift > 0) {
- Case += " Value |= (op & " + utostr(opMask) + "U) << "
- + itostr(opShift) + ";\n";
- } else if (opShift < 0) {
- Case += " Value |= (op & " + utostr(opMask) + "U) >> "
- + itostr(-opShift) + ";\n";
- } else {
- Case += " Value |= op & " + utostr(opMask) + "U;\n";
- }
- }
- }
- }
- }
+ const std::string &InstName = R->getValueAsString("Namespace") + "::"
+ + R->getName();
+ std::string Case = getInstructionCase(R, Target);
- std::vector<std::string> &InstList = CaseMap[Case];
- InstList.push_back(InstName);
+ CaseMap[Case].push_back(InstName);
}
-
// Emit initial function code
o << " const unsigned opcode = MI.getOpcode();\n"
<< " unsigned Value = InstBits[opcode];\n"
<< " unsigned op = 0;\n"
- << " op = op; // suppress warning\n"
+ << " (void)op; // suppress warning\n"
<< " switch (opcode) {\n";
// Emit each case statement
for (int i = 0, N = InstList.size(); i < N; i++) {
if (i) o << "\n";
- o << " case " << Namespace << InstList[i] << ":";
+ o << " case " << InstList[i] << ":";
}
o << " {\n";
o << Case;
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