+ 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];