Added invariant field to the DAG.getLoad method and changed all calls.

When this field is true it means that the load is from constant (runt-time or compile-time) and so can be hoisted from loops or moved around other memory accesses


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144100 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/CodeGen/MachineMemOperand.h

@@ -95,8 +95,10 @@ public:
     MOVolatile = 4,
     /// The memory access is non-temporal.
     MONonTemporal = 8,
+    /// The memory access is invariant.
+    MOInvariant = 16,
     // This is the number of bits we need to represent flags.
-    MOMaxBits = 4
+    MOMaxBits = 5
   };
 
   /// MachineMemOperand - Construct an MachineMemOperand object with the
@@ -141,6 +143,7 @@ public:
   bool isStore() const { return Flags & MOStore; }
   bool isVolatile() const { return Flags & MOVolatile; }
   bool isNonTemporal() const { return Flags & MONonTemporal; }
+  bool isInvariant() const { return Flags & MOInvariant; }
 
   /// refineAlignment - Update this MachineMemOperand to reflect the alignment
   /// of MMO, if it has a greater alignment. This must only be used when the