+/// HashMachineInstr - Compute a hash value for MI and its operands.
+static unsigned HashMachineInstr(const MachineInstr *MI) {
+ unsigned Hash = MI->getOpcode();
+ for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+ const MachineOperand &Op = MI->getOperand(i);
+
+ // Merge in bits from the operand if easy. We can't use MachineOperand's
+ // hash_code here because it's not deterministic and we sort by hash value
+ // later.
+ unsigned OperandHash = 0;
+ switch (Op.getType()) {
+ case MachineOperand::MO_Register:
+ OperandHash = Op.getReg();
+ break;
+ case MachineOperand::MO_Immediate:
+ OperandHash = Op.getImm();
+ break;
+ case MachineOperand::MO_MachineBasicBlock:
+ OperandHash = Op.getMBB()->getNumber();
+ break;
+ case MachineOperand::MO_FrameIndex:
+ case MachineOperand::MO_ConstantPoolIndex:
+ case MachineOperand::MO_JumpTableIndex:
+ OperandHash = Op.getIndex();
+ break;
+ case MachineOperand::MO_GlobalAddress:
+ case MachineOperand::MO_ExternalSymbol:
+ // Global address / external symbol are too hard, don't bother, but do
+ // pull in the offset.
+ OperandHash = Op.getOffset();
+ break;
+ default:
+ break;
+ }
+
+ Hash += ((OperandHash << 3) | Op.getType()) << (i & 31);
+ }
+ return Hash;
+}
+