Tristate mayLoad, mayStore, and hasSideEffects.

Keep track of the set/unset state of these bits along with their
true/false values, but treat '?' as '0' for now.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162461 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 9 insertions, 3 deletions

diff --git a/include/llvm/TableGen/Record.h b/include/llvm/TableGen/Record.h
index add5131..75ca88a 100644
--- a/include/llvm/TableGen/Record.h
+++ b/include/llvm/TableGen/Record.h
@@ -1511,6 +1511,12 @@ public:
   ///
   bool getValueAsBit(StringRef FieldName) const;
 
+  /// getValueAsBitOrUnset - This method looks up the specified field and
+  /// returns its value as a bit. If the field is unset, sets Unset to true and
+  /// retunrs false.
+  ///
+  bool getValueAsBitOrUnset(StringRef FieldName, bool &Unset) const;
+
   /// getValueAsInt - This method looks up the specified field and returns its
   /// value as an int64_t, throwing an exception if the field does not exist or
   /// if the value is not the right type.
diff --git a/include/llvm/Target/Target.td b/include/llvm/Target/Target.td
index 1f86607..f0458ec 100644
--- a/include/llvm/Target/Target.td
+++ b/include/llvm/Target/Target.td
@@ -343,8 +343,8 @@ class Instruction {
   bit isBarrier    = 0;     // Can control flow fall through this instruction?
   bit isCall       = 0;     // Is this instruction a call instruction?
   bit canFoldAsLoad = 0;    // Can this be folded as a simple memory operand?
-  bit mayLoad      = 0;     // Is it possible for this inst to read memory?
-  bit mayStore     = 0;     // Is it possible for this inst to write memory?
+  bit mayLoad      = ?;     // Is it possible for this inst to read memory?
+  bit mayStore     = ?;     // Is it possible for this inst to write memory?
   bit isConvertibleToThreeAddress = 0;  // Can this 2-addr instruction promote?
   bit isCommutable = 0;     // Is this 3 operand instruction commutable?
   bit isTerminator = 0;     // Is this part of the terminator for a basic block?
@@ -369,7 +369,7 @@ class Instruction {
   //
   //  neverHasSideEffects - Set on an instruction with no pattern if it has no
   //    side effects.
-  bit hasSideEffects = 0;
+  bit hasSideEffects = ?;
   bit neverHasSideEffects = 0;
 
   // Is this instruction a "real" instruction (with a distinct machine