[MachineVerifier] Include offending register in allocatable live-in error msg.

This patch adds a convenience report() method for physical registers and
uses it to print the offending register with the 'MBB has allocatable
live-in' error.

Reviewers: MatzeB, rtereshin, dsanders

Reviewed By: dsanders

Differential Revision: https://reviews.llvm.org/D55946


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@350630 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/MachineVerifier.cpp b/lib/CodeGen/MachineVerifier.cpp
index f4804e7..3128e5a 100644
--- a/lib/CodeGen/MachineVerifier.cpp
+++ b/lib/CodeGen/MachineVerifier.cpp
@@ -250,6 +250,7 @@
     void report_context(const LiveRange::Segment &S) const;
     void report_context(const VNInfo &VNI) const;
     void report_context(SlotIndex Pos) const;
+    void report_context(MCPhysReg PhysReg) const;
     void report_context_liverange(const LiveRange &LR) const;
     void report_context_lanemask(LaneBitmask LaneMask) const;
     void report_context_vreg(unsigned VReg) const;
@@ -540,6 +541,10 @@
   errs() << "- liverange:   " << LR << '\n';
 }
 
+void MachineVerifier::report_context(MCPhysReg PReg) const {
+  errs() << "- p. register: " << printReg(PReg, TRI) << '\n';
+}
+
 void MachineVerifier::report_context_vreg(unsigned VReg) const {
   errs() << "- v. register: " << printReg(VReg, TRI) << '\n';
 }
@@ -619,6 +624,7 @@
       if (isAllocatable(LI.PhysReg) && !MBB->isEHPad() &&
           MBB->getIterator() != MBB->getParent()->begin()) {
         report("MBB has allocatable live-in, but isn't entry or landing-pad.", MBB);
+        report_context(LI.PhysReg);
       }
     }
   }