- Do away with SimpleHazardRecognizer.h. It's not used and offers little value.

- Rename ExactHazardRecognizer to PostRAHazardRecognizer and move its header to include to allow targets to extend it.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105959 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 93 insertions, 0 deletions

diff --git a/include/llvm/CodeGen/PostRAHazardRecognizer.h b/include/llvm/CodeGen/PostRAHazardRecognizer.h
new file mode 100644
index 0000000000..3f600f587d
--- /dev/null
+++ b/include/llvm/CodeGen/PostRAHazardRecognizer.h
@@ -0,0 +1,93 @@
+//=- llvm/CodeGen/PostRAHazardRecognizer.h - Scheduling Support -*- C++ -*-=//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the PostRAHazardRecognizer class, which
+// implements hazard-avoidance heuristics for scheduling, based on the
+// scheduling itineraries specified for the target.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CODEGEN_EXACTHAZARDRECOGNIZER_H
+#define LLVM_CODEGEN_EXACTHAZARDRECOGNIZER_H
+
+#include "llvm/CodeGen/ScheduleHazardRecognizer.h"
+#include "llvm/System/DataTypes.h"
+
+#include <cassert>
+#include <string>
+
+namespace llvm {
+
+class InstrItineraryData;
+class SUnit;
+
+class PostRAHazardRecognizer : public ScheduleHazardRecognizer {
+  // ScoreBoard to track function unit usage. ScoreBoard[0] is a
+  // mask of the FUs in use in the cycle currently being
+  // schedule. ScoreBoard[1] is a mask for the next cycle. The
+  // ScoreBoard is used as a circular buffer with the current cycle
+  // indicated by Head.
+  class ScoreBoard {
+    unsigned *Data;
+
+    // The maximum number of cycles monitored by the Scoreboard. This
+    // value is determined based on the target itineraries to ensure
+    // that all hazards can be tracked.
+    size_t Depth;
+    // Indices into the Scoreboard that represent the current cycle.
+    size_t Head;
+  public:
+    ScoreBoard():Data(NULL), Depth(0), Head(0) { }
+    ~ScoreBoard() {
+      delete[] Data;
+    }
+
+    size_t getDepth() const { return Depth; }
+    unsigned& operator[](size_t idx) const {
+      assert(Depth && "ScoreBoard was not initialized properly!");
+
+      return Data[(Head + idx) % Depth];
+    }
+
+    void reset(size_t d = 1) {
+      if (Data == NULL) {
+        Depth = d;
+        Data = new unsigned[Depth];
+      }
+
+      memset(Data, 0, Depth * sizeof(Data[0]));
+      Head = 0;
+    }
+
+    void advance() {
+      Head = (Head + 1) % Depth;
+    }
+
+    // Print the scoreboard.
+    void dump() const;
+  };
+
+  // Itinerary data for the target.
+  const InstrItineraryData &ItinData;
+
+  ScoreBoard ReservedScoreboard;
+  ScoreBoard RequiredScoreboard;
+
+public:
+  PostRAHazardRecognizer(const InstrItineraryData &ItinData);
+
+  virtual HazardType getHazardType(SUnit *SU);
+  virtual void Reset();
+  virtual void EmitInstruction(SUnit *SU);
+  virtual void AdvanceCycle();
+};
+
+}
+
+#endif