Generalize the HazardRecognizer interface so that it can be used

to support MachineInstr-based scheduling in addition to
SDNode-based scheduling.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62284 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 82 insertions, 42 deletions

diff --git a/include/llvm/CodeGen/ScheduleDAGSDNodes.h b/include/llvm/CodeGen/ScheduleDAGSDNodes.h
index 6fc1493..7d62b35 100644
--- a/include/llvm/CodeGen/ScheduleDAGSDNodes.h
+++ b/include/llvm/CodeGen/ScheduleDAGSDNodes.h
@@ -19,45 +19,6 @@
 #include "llvm/CodeGen/SelectionDAG.h"
 
 namespace llvm {
-  /// HazardRecognizer - This determines whether or not an instruction can be
-  /// issued this cycle, and whether or not a noop needs to be inserted to handle
-  /// the hazard.
-  class HazardRecognizer {
-  public:
-    virtual ~HazardRecognizer();
-    
-    enum HazardType {
-      NoHazard,      // This instruction can be emitted at this cycle.
-      Hazard,        // This instruction can't be emitted at this cycle.
-      NoopHazard     // This instruction can't be emitted, and needs noops.
-    };
-    
-    /// getHazardType - Return the hazard type of emitting this node.  There are
-    /// three possible results.  Either:
-    ///  * NoHazard: it is legal to issue this instruction on this cycle.
-    ///  * Hazard: issuing this instruction would stall the machine.  If some
-    ///     other instruction is available, issue it first.
-    ///  * NoopHazard: issuing this instruction would break the program.  If
-    ///     some other instruction can be issued, do so, otherwise issue a noop.
-    virtual HazardType getHazardType(SDNode *) {
-      return NoHazard;
-    }
-    
-    /// EmitInstruction - This callback is invoked when an instruction is
-    /// emitted, to advance the hazard state.
-    virtual void EmitInstruction(SDNode *) {}
-    
-    /// AdvanceCycle - This callback is invoked when no instructions can be
-    /// issued on this cycle without a hazard.  This should increment the
-    /// internal state of the hazard recognizer so that previously "Hazard"
-    /// instructions will now not be hazards.
-    virtual void AdvanceCycle() {}
-    
-    /// EmitNoop - This callback is invoked when a noop was added to the
-    /// instruction stream.
-    virtual void EmitNoop() {}
-  };
-
   /// ScheduleDAGSDNodes - A ScheduleDAG for scheduling SDNode-based DAGs.
   /// 
   /// Edges between SUnits are initially based on edges in the SelectionDAG,
diff --git a/include/llvm/CodeGen/ScheduleHazardRecognizer.h b/include/llvm/CodeGen/ScheduleHazardRecognizer.h
new file mode 100644
index 0000000..5cf45f7
--- /dev/null
+++ b/include/llvm/CodeGen/ScheduleHazardRecognizer.h
@@ -0,0 +1,63 @@
+//=- llvm/CodeGen/ScheduleHazardRecognizer.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 ScheduleHazardRecognizer class, which implements
+// hazard-avoidance heuristics for scheduling.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CODEGEN_SCHEDULEHAZARDRECOGNIZER_H
+#define LLVM_CODEGEN_SCHEDULEHAZARDRECOGNIZER_H
+
+namespace llvm {
+
+class SUnit;
+
+/// HazardRecognizer - This determines whether or not an instruction can be
+/// issued this cycle, and whether or not a noop needs to be inserted to handle
+/// the hazard.
+class ScheduleHazardRecognizer {
+public:
+  virtual ~ScheduleHazardRecognizer();
+
+  enum HazardType {
+    NoHazard,      // This instruction can be emitted at this cycle.
+    Hazard,        // This instruction can't be emitted at this cycle.
+    NoopHazard     // This instruction can't be emitted, and needs noops.
+  };
+
+  /// getHazardType - Return the hazard type of emitting this node.  There are
+  /// three possible results.  Either:
+  ///  * NoHazard: it is legal to issue this instruction on this cycle.
+  ///  * Hazard: issuing this instruction would stall the machine.  If some
+  ///     other instruction is available, issue it first.
+  ///  * NoopHazard: issuing this instruction would break the program.  If
+  ///     some other instruction can be issued, do so, otherwise issue a noop.
+  virtual HazardType getHazardType(SUnit *) {
+    return NoHazard;
+  }
+
+  /// EmitInstruction - This callback is invoked when an instruction is
+  /// emitted, to advance the hazard state.
+  virtual void EmitInstruction(SUnit *) {}
+
+  /// AdvanceCycle - This callback is invoked when no instructions can be
+  /// issued on this cycle without a hazard.  This should increment the
+  /// internal state of the hazard recognizer so that previously "Hazard"
+  /// instructions will now not be hazards.
+  virtual void AdvanceCycle() {}
+
+  /// EmitNoop - This callback is invoked when a noop was added to the
+  /// instruction stream.
+  virtual void EmitNoop() {}
+};
+
+}
+
+#endif
diff --git a/include/llvm/CodeGen/SelectionDAGISel.h b/include/llvm/CodeGen/SelectionDAGISel.h
index 072cb0c..1b680f7 100644
--- a/include/llvm/CodeGen/SelectionDAGISel.h
+++ b/include/llvm/CodeGen/SelectionDAGISel.h
@@ -33,7 +33,7 @@ namespace llvm {
   class TargetLowering;
   class TargetInstrInfo;
   class FunctionLoweringInfo;
-  class HazardRecognizer;
+  class ScheduleHazardRecognizer;
   class GCFunctionInfo;
   class ScheduleDAG;
  
@@ -93,7 +93,7 @@ public:
   
   /// CreateTargetHazardRecognizer - Return a newly allocated hazard recognizer
   /// to use for this target when scheduling the DAG.
-  virtual HazardRecognizer *CreateTargetHazardRecognizer();
+  virtual ScheduleHazardRecognizer *CreateTargetHazardRecognizer();
   
 protected:
   /// DAGSize - Size of DAG being instruction selected.
diff --git a/include/llvm/CodeGen/SelectionDAGNodes.h b/include/llvm/CodeGen/SelectionDAGNodes.h
index 345def3..3b7d208 100644
--- a/include/llvm/CodeGen/SelectionDAGNodes.h
+++ b/include/llvm/CodeGen/SelectionDAGNodes.h
@@ -1293,7 +1293,23 @@ public:
       return getOperand(getNumOperands()-1).getNode();
     return 0;
   }
-  
+
+  // If this is a pseudo op, like copyfromreg, look to see if there is a
+  // real target node flagged to it.  If so, return the target node.
+  const SDNode *getFlaggedMachineNode() const {
+    const SDNode *FoundNode = this;
+
+    // Climb up flag edges until a machine-opcode node is found, or the
+    // end of the chain is reached.
+    while (!FoundNode->isMachineOpcode()) {
+      const SDNode *N = FoundNode->getFlaggedNode();
+      if (!N) break;
+      FoundNode = N;
+    }
+
+    return FoundNode;
+  }
+
   /// getNumValues - Return the number of values defined/returned by this
   /// operator.
   ///