Skip over zero registers.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63748 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/SimpleRegisterCoalescing.cpp b/lib/CodeGen/SimpleRegisterCoalescing.cpp
index f3ffc69cccbe5efffed6c6de78f4a66696b55f14..86dca115194a5741767ce66067021ca30078955f 100644 (file)
--- a/lib/CodeGen/SimpleRegisterCoalescing.cpp
+++ b/lib/CodeGen/SimpleRegisterCoalescing.cpp
@@ -2449,6 +2449,8 @@ bool SimpleRegisterCoalescing::runOnMachineFunction(MachineFunction &fn) {
           if (!MO.isReg())
             continue;
           unsigned Reg = MO.getReg();
+          if (!Reg)
+            continue;
           if (TargetRegisterInfo::isVirtualRegister(Reg))
             DeadDefs.push_back(Reg);
           if (MO.isDead())