[MachineVerifier] Add check that tied physregs aren't different.

Summary: Added MachineVerifier code to check register ties more thoroughly, especially so that physical registers that are tied are the same. This may help e.g. when creating MIR files.

Original patch by Jesper Antonsson

Reviewers: stoklund, sanjoy, qcolombet

Reviewed By: qcolombet

Subscribers: qcolombet, llvm-commits

Differential Revision: https://reviews.llvm.org/D34394

llvm-svn: 307259

1 files changed, 8 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/MachineVerifier.cpp b/llvm/lib/CodeGen/MachineVerifier.cpp
index e65c256c1bb..fcb544806dd 100644
--- a/llvm/lib/CodeGen/MachineVerifier.cpp
+++ b/llvm/lib/CodeGen/MachineVerifier.cpp
@@ -985,6 +985,14 @@ MachineVerifier::visitMachineOperand(const MachineOperand *MO, unsigned MONum) {
         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 {