+ // Process sub-register sets.
+ for (unsigned i = 0, e = Regs.size(); i != e; ++i) {
+ Record *R = Regs[i].TheDef;
+ std::vector<Record*> LI = Regs[i].TheDef->getValueAsListOfDefs("SubRegs");
+ // Process sub-register set and add aliases information.
+ for (unsigned j = 0, e = LI.size(); j != e; ++j) {
+ Record *SubReg = LI[j];
+ if (RegisterSubRegs[R].count(SubReg))
+ cerr << "Warning: register " << getQualifiedName(SubReg)
+ << " specified as a sub-register of " << getQualifiedName(R)
+ << " multiple times!\n";
+ addSubSuperReg(R, SubReg, RegisterSubRegs, RegisterSuperRegs,
+ RegisterAliases);
+ }
+ }
+
+ // Print the SubregHashTable, a simple quadratically probed
+ // hash table for determining if a register is a subregister
+ // of another register.
+ unsigned NumSubRegs = 0;
+ std::map<Record*, unsigned> RegNo;
+ for (unsigned i = 0, e = Regs.size(); i != e; ++i) {
+ RegNo[Regs[i].TheDef] = i;
+ NumSubRegs += RegisterSubRegs[Regs[i].TheDef].size();
+ }
+
+ unsigned SubregHashTableSize = 2 * NextPowerOf2(2 * NumSubRegs);
+ unsigned* SubregHashTable = new unsigned[2 * SubregHashTableSize];
+ std::fill(SubregHashTable, SubregHashTable + 2 * SubregHashTableSize, ~0U);
+
+ unsigned hashMisses = 0;
+
+ for (unsigned i = 0, e = Regs.size(); i != e; ++i) {
+ Record* R = Regs[i].TheDef;
+ for (std::set<Record*>::iterator I = RegisterSubRegs[R].begin(),
+ E = RegisterSubRegs[R].end(); I != E; ++I) {
+ Record* RJ = *I;
+ // We have to increase the indices of both registers by one when
+ // computing the hash because, in the generated code, there
+ // will be an extra empty slot at register 0.
+ size_t index = ((i+1) + (RegNo[RJ]+1) * 37) & (SubregHashTableSize-1);
+ unsigned ProbeAmt = 2;
+ while (SubregHashTable[index*2] != ~0U &&
+ SubregHashTable[index*2+1] != ~0U) {
+ index = (index + ProbeAmt) & (SubregHashTableSize-1);
+ ProbeAmt += 2;
+
+ hashMisses++;
+ }
+
+ SubregHashTable[index*2] = i;
+ SubregHashTable[index*2+1] = RegNo[RJ];
+ }
+ }
+
+ OS << "\n\n // Number of hash collisions: " << hashMisses << "\n";
+
+ if (SubregHashTableSize) {
+ std::string Namespace = Regs[0].TheDef->getValueAsString("Namespace");
+
+ OS << " const unsigned SubregHashTable[] = { ";
+ for (unsigned i = 0; i < SubregHashTableSize - 1; ++i) {
+ if (i != 0)
+ // Insert spaces for nice formatting.
+ OS << " ";
+
+ if (SubregHashTable[2*i] != ~0U) {
+ OS << getQualifiedName(Regs[SubregHashTable[2*i]].TheDef) << ", "
+ << getQualifiedName(Regs[SubregHashTable[2*i+1]].TheDef) << ", \n";
+ } else {
+ OS << Namespace << "::NoRegister, " << Namespace << "::NoRegister, \n";
+ }
+ }
+
+ unsigned Idx = SubregHashTableSize*2-2;
+ if (SubregHashTable[Idx] != ~0U) {
+ OS << " "
+ << getQualifiedName(Regs[SubregHashTable[Idx]].TheDef) << ", "
+ << getQualifiedName(Regs[SubregHashTable[Idx+1]].TheDef) << " };\n";
+ } else {
+ OS << Namespace << "::NoRegister, " << Namespace << "::NoRegister };\n";
+ }
+
+ OS << " const unsigned SubregHashTableSize = "
+ << SubregHashTableSize << ";\n";
+ } else {
+ OS << " const unsigned SubregHashTable[] = { ~0U, ~0U };\n"
+ << " const unsigned SubregHashTableSize = 1;\n";
+ }
+
+ delete [] SubregHashTable;
+