Verify a couple more fields in STATEPOINT instructions

While doing so, clarify the comments and update them to reflect current reality.

Note: I'm going to let this sit for a week or so before adding further verification.  I want to give this time to cycle through bots and merge it into our downstream tree before pushing this further.
llvm-svn: 304565

1 files changed, 14 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/MachineVerifier.cpp b/llvm/lib/CodeGen/MachineVerifier.cpp
index d40694ce91e..f6dbf667cf0 100644
--- a/llvm/lib/CodeGen/MachineVerifier.cpp
+++ b/llvm/lib/CodeGen/MachineVerifier.cpp
@@ -932,6 +932,20 @@ void MachineVerifier::visitMachineInstrBefore(const MachineInstr *MI) {
         !MI->getOperand(StatepointOpers::NCallArgsPos).isImm())
       report("meta operands to STATEPOINT not constant!", MI);
     break;
+
+    auto VerifyStackMapConstant = [&](unsigned Offset) {
+      if (!MI->getOperand(Offset).isImm() ||
+          MI->getOperand(Offset).getImm() != StackMaps::ConstantOp || 
+          !MI->getOperand(Offset + 1).isImm()) 
+        report("stack map constant to STATEPOINT not well formed!", MI);
+    };
+    const unsigned VarStart = StatepointOpers(MI).getVarIdx();
+    VerifyStackMapConstant(VarStart + StatepointOpers::CCOffset);
+    VerifyStackMapConstant(VarStart + StatepointOpers::FlagsOffset);
+    VerifyStackMapConstant(VarStart + StatepointOpers::NumDeoptOperandsOffset);
+
+    // TODO: verify we have properly encoded deopt arguments
+   
   };
 }