Aggressively prune the DFS when inserting phi-defs.

[oota-llvm.git] / include / llvm / Target / TargetInstrItineraries.h

diff --git a/include/llvm/Target/TargetInstrItineraries.h b/include/llvm/Target/TargetInstrItineraries.h
index 0e4ca985ddd8b8c9f0e125f15b9534cf50aa4f33..39648c233fa8b8e27dbf81d49080e5856c93537d 100644 (file)
--- a/include/llvm/Target/TargetInstrItineraries.h
+++ b/include/llvm/Target/TargetInstrItineraries.h
@@ -47,10 +47,24 @@ namespace llvm {
 ///      indicate that the instruction requires multiple stages at the
 ///      same time.
 ///
+/// FU reservation can be of two different kinds:
+///  - FUs which instruction actually requires
+///  - FUs which instruction just reserves. Reserved unit is not available for
+///    execution of other instruction. However, several instructions can reserve
+///    the same unit several times.
+/// Such two types of units reservation is used to model instruction domain
+/// change stalls, FUs using the same resource (e.g. same register file), etc.
+
 struct InstrStage {
+  enum ReservationKinds {
+    Required = 0,
+    Reserved = 1
+  };
+
   unsigned Cycles_;  ///< Length of stage in machine cycles
   unsigned Units_;   ///< Choice of functional units
-  int NextCycles_;   ///< Number of machine cycles to next stage 
+  int NextCycles_;   ///< Number of machine cycles to next stage
+  ReservationKinds Kind_; ///< Kind of the FU reservation
 
   /// getCycles - returns the number of cycles the stage is occupied
   unsigned getCycles() const {
@@ -62,6 +76,10 @@ struct InstrStage {
     return Units_;
   }
 
+  ReservationKinds getReservationKind() const {
+    return Kind_;
+  }
+
   /// getNextCycles - returns the number of cycles from the start of
   /// this stage to the start of the next stage in the itinerary
   unsigned getNextCycles() const {
@@ -88,7 +106,8 @@ struct InstrItinerary {
 /// Instruction itinerary Data - Itinerary data supplied by a subtarget to be
 /// used by a target.
 ///
-struct InstrItineraryData {
+class InstrItineraryData {
+public:
   const InstrStage     *Stages;         ///< Array of stages selected
   const unsigned       *OperandCycles;  ///< Array of operand cycles selected
   const InstrItinerary *Itineratries;   ///< Array of itineraries selected
@@ -104,6 +123,14 @@ struct InstrItineraryData {
   ///
   bool isEmpty() const { return Itineratries == 0; }
 
+  /// isEndMarker - Returns true if the index is for the end marker
+  /// itinerary.
+  ///
+  bool isEndMarker(unsigned ItinClassIndx) const {
+    return ((Itineratries[ItinClassIndx].FirstStage == ~0U) &&
+            (Itineratries[ItinClassIndx].LastStage == ~0U));
+  }
+
   /// beginStage - Return the first stage of the itinerary.
   /// 
   const InstrStage *beginStage(unsigned ItinClassIndx) const {