- unsigned numBits = BI->getNumBits();
- BitsInit *NewBI = new BitsInit(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);
- }
- if (numBits % 2) {
- unsigned middle = (numBits + 1) / 2;
- NewBI->setBit(middle, BI->getBit(middle));
+ void run(raw_ostream &o);
+private:
+ int getVariableBit(const std::string &VarName, BitsInit *BI, int bit);
+ std::string getInstructionCase(Record *R, CodeGenTarget &Target);
+ void AddCodeToMergeInOperand(Record *R, BitsInit *BI,
+ const std::string &VarName,
+ unsigned &NumberedOp,
+ std::set<unsigned> &NamedOpIndices,
+ std::string &Case, CodeGenTarget &Target);
+
+};
+
+// 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 = dyn_cast<VarBitInit>(BI->getBit(bit))) {
+ if (VarInit *VI = dyn_cast<VarInit>(VBI->getBitVar()))
+ if (VI->getName() == VarName)
+ return VBI->getBitNum();
+ } else if (VarInit *VI = dyn_cast<VarInit>(BI->getBit(bit))) {
+ if (VI->getName() == VarName)
+ return 0;
+ }
+
+ return -1;
+}
+
+void CodeEmitterGen::
+AddCodeToMergeInOperand(Record *R, BitsInit *BI, const std::string &VarName,
+ unsigned &NumberedOp,
+ std::set<unsigned> &NamedOpIndices,
+ 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 {
+ unsigned NumberOps = CGI.Operands.size();
+ /// If this operand is not supposed to be emitted by the
+ /// generated emitter, skip it.
+ while (NumberedOp < NumberOps &&
+ (CGI.Operands.isFlatOperandNotEmitted(NumberedOp) ||
+ (!NamedOpIndices.empty() && NamedOpIndices.count(
+ CGI.Operands.getSubOperandNumber(NumberedOp).first)))) {
+ ++NumberedOp;
+
+ if (NumberedOp >= CGI.Operands.back().MIOperandNo +
+ CGI.Operands.back().MINumOperands) {
+ errs() << "Too few operands in record " << R->getName() <<
+ " (no match for variable " << VarName << "):\n";
+ errs() << *R;
+ errs() << '\n';
+
+ return;
+ }