Add flags to indicate that there are "never" side effects or that there "may be"
side effects for machine instructions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45022 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/utils/TableGen/CodeGenTarget.cpp b/utils/TableGen/CodeGenTarget.cpp
index 47bbecb..a2fe370 100644
--- a/utils/TableGen/CodeGenTarget.cpp
+++ b/utils/TableGen/CodeGenTarget.cpp
@@ -395,9 +395,15 @@
   usesCustomDAGSchedInserter = R->getValueAsBit("usesCustomDAGSchedInserter");
   hasCtrlDep   = R->getValueAsBit("hasCtrlDep");
   isNotDuplicable = R->getValueAsBit("isNotDuplicable");
+  mayHaveSideEffects = R->getValueAsBit("mayHaveSideEffects");
+  neverHasSideEffects = R->getValueAsBit("neverHasSideEffects");
   hasOptionalDef = false;
   hasVariableNumberOfOperands = false;
-  
+
+  if (mayHaveSideEffects && neverHasSideEffects)
+    throw R->getName() +
+      ": cannot have both 'mayHaveSideEffects' and 'neverHasSideEffects' set!";
+
   DagInit *DI;
   try {
     DI = R->getValueAsDag("OutOperandList");