Add function that translates subregister lane masks to other subregs.

[oota-llvm.git] / utils / TableGen / CodeGenRegisters.h

diff --git a/utils/TableGen/CodeGenRegisters.h b/utils/TableGen/CodeGenRegisters.h
index 6baaa28d95ddc2f1e4e9caad96d4e128a70d5e63..d4668a05f332569f9221433548754a656fb1364c 100644 (file)
--- a/utils/TableGen/CodeGenRegisters.h
+++ b/utils/TableGen/CodeGenRegisters.h
@@ -34,6 +34,20 @@
 namespace llvm {
   class CodeGenRegBank;
 
+  /// Used to encode a step in a register lane mask transformation.
+  /// Mask the bits specified in Mask, then rotate them Rol bits to the left
+  /// assuming a wraparound at 32bits.
+  struct MaskRolPair {
+    unsigned Mask;
+    uint8_t RotateLeft;
+    bool operator==(const MaskRolPair Other) {
+      return Mask == Other.Mask && RotateLeft == Other.RotateLeft;
+    }
+    bool operator!=(const MaskRolPair Other) {
+      return Mask != Other.Mask || RotateLeft != Other.RotateLeft;
+    }
+  };
+
   /// CodeGenSubRegIndex - Represents a sub-register index.
   class CodeGenSubRegIndex {
     Record *const TheDef;
@@ -45,6 +59,7 @@ namespace llvm {
     uint16_t Offset;
     const unsigned EnumValue;
     mutable unsigned LaneMask;
+    mutable SmallVector<MaskRolPair,1> CompositionLaneMaskTransform;
 
     // Are all super-registers containing this SubRegIndex covered by their
     // sub-registers?