Use the schedule itinerary operand use/def cycle information to adjust dependence edge latency for post-RA scheduling.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79425 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 32 insertions, 12 deletions

diff --git a/include/llvm/CodeGen/ScheduleDAG.h b/include/llvm/CodeGen/ScheduleDAG.h
index ead3d3db26..f820200f99 100644
--- a/include/llvm/CodeGen/ScheduleDAG.h
+++ b/include/llvm/CodeGen/ScheduleDAG.h
@@ -495,6 +495,12 @@ namespace llvm {
     ///
     virtual void ComputeLatency(SUnit *SU) = 0;
 
+    /// ComputeOperandLatency - Override dependence edge latency using
+    /// operand use/def information
+    ///
+    virtual void ComputeOperandLatency(SUnit *Def, SUnit *Use,
+                                       SDep& dep) const { };
+
     /// Schedule - Order nodes according to selected style, filling
     /// in the Sequence member.
     ///
diff --git a/include/llvm/Target/TargetInstrItineraries.h b/include/llvm/Target/TargetInstrItineraries.h
index 9ba9cb61c5..0e4ca985dd 100644
--- a/include/llvm/Target/TargetInstrItineraries.h
+++ b/include/llvm/Target/TargetInstrItineraries.h
@@ -103,7 +103,7 @@ struct InstrItineraryData {
   /// isEmpty - Returns true if there are no itineraries.
   ///
   bool isEmpty() const { return Itineratries == 0; }
-  
+
   /// beginStage - Return the first stage of the itinerary.
   /// 
   const InstrStage *beginStage(unsigned ItinClassIndx) const {
@@ -118,20 +118,17 @@ struct InstrItineraryData {
     return Stages + StageIdx;
   }
 
-  /// getLatency - Return the scheduling latency of the given class.  A
-  /// simple latency value for an instruction is an over-simplification
-  /// for some architectures, but it's a reasonable first approximation.
+  /// getStageLatency - Return the total stage latency of the given
+  /// class.  The latency is the maximum completion time for any stage
+  /// in the itinerary.
   ///
-  unsigned getLatency(unsigned ItinClassIndx) const {
-    // If the target doesn't provide latency information, use a simple
-    // non-zero default value for all instructions.
+  unsigned getStageLatency(unsigned ItinClassIndx) const {
+    // If the target doesn't provide itinerary information, use a
+    // simple non-zero default value for all instructions.
     if (isEmpty())
       return 1;
 
-    // Caclulate the maximum completion time for any stage. The
-    // assumption is that all inputs are consumed at the start of the
-    // first stage and that all outputs are produced at the end of the
-    // latest completing last stage.
+    // Calculate the maximum completion time for any stage.
     unsigned Latency = 0, StartCycle = 0;
     for (const InstrStage *IS = beginStage(ItinClassIndx),
            *E = endStage(ItinClassIndx); IS != E; ++IS) {
@@ -141,6 +138,21 @@ struct InstrItineraryData {
 
     return Latency;
   }
+
+  /// getOperandCycle - Return the cycle for the given class and
+  /// operand. Return -1 if no cycle is specified for the operand.
+  ///
+  int getOperandCycle(unsigned ItinClassIndx, unsigned OperandIdx) const {
+    if (isEmpty())
+      return -1;
+
+    unsigned FirstIdx = Itineratries[ItinClassIndx].FirstOperandCycle;
+    unsigned LastIdx = Itineratries[ItinClassIndx].LastOperandCycle;
+    if ((FirstIdx + OperandIdx) >= LastIdx)
+      return -1;
+
+    return (int)OperandCycles[FirstIdx + OperandIdx];
+  }
 };
 
 
diff --git a/include/llvm/Target/TargetSubtarget.h b/include/llvm/Target/TargetSubtarget.h
index c86e81554c..14f612af97 100644
--- a/include/llvm/Target/TargetSubtarget.h
+++ b/include/llvm/Target/TargetSubtarget.h
@@ -17,6 +17,7 @@
 namespace llvm {
 
 class SDep;
+class SUnit;
 
 //===----------------------------------------------------------------------===//
 ///
@@ -40,7 +41,8 @@ public:
 
   // adjustSchedDependency - Perform target specific adjustments to
   // the latency of a schedule dependency.
-  virtual void adjustSchedDependency(SDep&) const { };
+  virtual void adjustSchedDependency(SUnit *def, SUnit *use, 
+                                     SDep& dep) const { };
 };
 
 } // End llvm namespace