Extend machine verifier to check for multiple defs.

Author: AbhayKanhere

llvm/lib/CodeGen/MachineVerifier.cpp

@@ -2326,12 +2326,14 @@ void MachineVerifier::visitMachineInstrBefore(const MachineInstr *MI) {
   }
 
   // Verify earlyClobber def operand
-  if (MCID.getOperandConstraint(0, MCOI::EARLY_CLOBBER) != -1) {
-    if (!MI->getOperand(0).isReg())
-      report("Early clobber must be a register", MI);
-    if (!MI->getOperand(0).isEarlyClobber())
-      report("Missing earlyClobber flag", MI);
-  }
+  for (unsigned i = 0; i < MI->getNumOperands(); i++)
+    if (MCID.getOperandConstraint(i, MCOI::EARLY_CLOBBER) != -1) {
+      const MachineOperand &Op = MI->getOperand(i);
+      if (!Op.isReg())
+        report("Early clobber must be a register", MI);
+      if (!Op.isEarlyClobber())
+        report("Missing earlyClobber flag", MI);
+    }
   // Debug values must not have a slot index.
   // Other instructions must have one, unless they are inside a bundle.
   if (LiveInts) {