Index: llvm/trunk/lib/CodeGen/MachineVerifier.cpp
===================================================================
--- llvm/trunk/lib/CodeGen/MachineVerifier.cpp
+++ llvm/trunk/lib/CodeGen/MachineVerifier.cpp
@@ -985,6 +985,14 @@
         report("Operand should be tied", MO, MONum);
       else if (unsigned(TiedTo) != MI->findTiedOperandIdx(MONum))
         report("Tied def doesn't match MCInstrDesc", MO, MONum);
+      else if (TargetRegisterInfo::isPhysicalRegister(MO->getReg())) {
+        const MachineOperand &MOTied = MI->getOperand(TiedTo);
+        if (!MOTied.isReg())
+          report("Tied counterpart must be a register", &MOTied, TiedTo);
+        else if (TargetRegisterInfo::isPhysicalRegister(MOTied.getReg()) &&
+                 MO->getReg() != MOTied.getReg())
+          report("Tied physical registers must match.", &MOTied, TiedTo);
+      }
     } else if (MO->isReg() && MO->isTied())
       report("Explicit operand should not be tied", MO, MONum);
   } else {
Index: llvm/trunk/test/CodeGen/MIR/X86/tied-physical-regs-match.mir
===================================================================
--- llvm/trunk/test/CodeGen/MIR/X86/tied-physical-regs-match.mir
+++ llvm/trunk/test/CodeGen/MIR/X86/tied-physical-regs-match.mir
@@ -0,0 +1,22 @@
+# RUN: not llc -march=x86-64 -run-pass none -o /dev/null %s 2>&1 | FileCheck %s
+# This test ensures that the Machine Verifier detects tied physical registers
+# that doesn't match.
+
+--- |
+
+  define i32 @foo() {
+  entry:
+    ret i32 0
+  }
+
+...
+---
+name:            foo
+body: |
+  bb.0.entry:
+    liveins: %rdi
+
+    ; CHECK: Tied physical registers must match.
+    %rbx = AND64rm killed %rdx, killed %rdi, 1, _, 0, _, implicit-def dead %eflags
+    RETQ %rbx
+...