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

3 files changed, 12 insertions, 8 deletions

diff --git a/include/llvm/CodeGen/MachineMemOperand.h b/include/llvm/CodeGen/MachineMemOperand.h
index 768ce47f8b..c01597ea67 100644
--- a/include/llvm/CodeGen/MachineMemOperand.h
+++ b/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
diff --git a/include/llvm/CodeGen/SelectionDAG.h b/include/llvm/CodeGen/SelectionDAG.h
index 132983c504..e4de462e00 100644
--- a/include/llvm/CodeGen/SelectionDAG.h
+++ b/include/llvm/CodeGen/SelectionDAG.h
@@ -650,7 +650,7 @@ public:
   ///
   SDValue getLoad(EVT VT, DebugLoc dl, SDValue Chain, SDValue Ptr,
                   MachinePointerInfo PtrInfo, bool isVolatile,
-                  bool isNonTemporal, unsigned Alignment,
+                  bool isNonTemporal, bool isInvariant, unsigned Alignment,
                   const MDNode *TBAAInfo = 0);
   SDValue getExtLoad(ISD::LoadExtType ExtType, DebugLoc dl, EVT VT,
                      SDValue Chain, SDValue Ptr, MachinePointerInfo PtrInfo,
@@ -663,8 +663,8 @@ public:
                   EVT VT, DebugLoc dl,
                   SDValue Chain, SDValue Ptr, SDValue Offset,
                   MachinePointerInfo PtrInfo, EVT MemVT,
-                  bool isVolatile, bool isNonTemporal, unsigned Alignment,
-                  const MDNode *TBAAInfo = 0);
+                  bool isVolatile, bool isNonTemporal, bool isInvariant,
+                  unsigned Alignment, const MDNode *TBAAInfo = 0);
   SDValue getLoad(ISD::MemIndexedMode AM, ISD::LoadExtType ExtType,
                   EVT VT, DebugLoc dl,
                   SDValue Chain, SDValue Ptr, SDValue Offset,
diff --git a/include/llvm/CodeGen/SelectionDAGNodes.h b/include/llvm/CodeGen/SelectionDAGNodes.h
index 6c7be69b4d..285f2fc373 100644
--- a/include/llvm/CodeGen/SelectionDAGNodes.h
+++ b/include/llvm/CodeGen/SelectionDAGNodes.h
@@ -917,12 +917,13 @@ public:
   // with MachineMemOperand information.
   bool isVolatile() const { return (SubclassData >> 5) & 1; }
   bool isNonTemporal() const { return (SubclassData >> 6) & 1; }
+  bool isInvariant() const { return (SubclassData >> 7) & 1; }
 
   AtomicOrdering getOrdering() const {
-    return AtomicOrdering((SubclassData >> 7) & 15);
+    return AtomicOrdering((SubclassData >> 8) & 15);
   }
   SynchronizationScope getSynchScope() const {
-    return SynchronizationScope((SubclassData >> 11) & 1);
+    return SynchronizationScope((SubclassData >> 12) & 1);
   }
 
   /// Returns the SrcValue and offset that describes the location of the access
@@ -993,8 +994,8 @@ class AtomicSDNode : public MemSDNode {
            "Ordering may not require more than 4 bits!");
     assert((SynchScope & 1) == SynchScope &&
            "SynchScope may not require more than 1 bit!");
-    SubclassData |= Ordering << 7;
-    SubclassData |= SynchScope << 11;
+    SubclassData |= Ordering << 8;
+    SubclassData |= SynchScope << 12;
     assert(getOrdering() == Ordering && "Ordering encoding error!");
     assert(getSynchScope() == SynchScope && "Synch-scope encoding error!");