Split scheduling from instruction selection.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52923 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/CodeGen/SelectionDAGISel.h b/include/llvm/CodeGen/SelectionDAGISel.h
index 54b4acc..7925a00 100644
--- a/include/llvm/CodeGen/SelectionDAGISel.h
+++ b/include/llvm/CodeGen/SelectionDAGISel.h
@@ -58,7 +58,9 @@
   unsigned MakeReg(MVT VT);
 
   virtual void EmitFunctionEntryCode(Function &Fn, MachineFunction &MF) {}
-  virtual void InstructionSelectBasicBlock(SelectionDAG &SD) = 0;
+  virtual void InstructionSelect(SelectionDAG &SD) = 0;
+  virtual void InstructionSelectPostProcessing(SelectionDAG &DAG) {}
+  
   virtual void SelectRootInit() {
     DAGSize = CurDAG->AssignTopologicalOrder(TopOrder);
   }
@@ -160,10 +162,6 @@
   };
   
 protected:
-  /// Pick a safe ordering and emit instructions for each target node in the
-  /// graph.
-  void ScheduleAndEmitDAG(SelectionDAG &DAG);
-  
   /// SelectInlineAsmMemoryOperands - Calls to this are automatically generated
   /// by tblgen.  Others should not call it.
   void SelectInlineAsmMemoryOperands(std::vector<SDOperand> &Ops,
@@ -187,6 +185,10 @@
   
   void ComputeLiveOutVRegInfo(SelectionDAG &DAG);
 
+  /// Pick a safe ordering and emit instructions for each target node in the
+  /// graph.
+  void ScheduleAndEmitDAG(SelectionDAG &DAG);
+
   /// SwitchCases - Vector of CaseBlock structures used to communicate
   /// SwitchInst code generation information.
   std::vector<CaseBlock> SwitchCases;
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index 1124f37..8cfc334 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -43,9 +43,10 @@
 #include "llvm/Target/TargetLowering.h"
 #include "llvm/Target/TargetMachine.h"
 #include "llvm/Target/TargetOptions.h"
-#include "llvm/Support/MathExtras.h"
-#include "llvm/Support/Debug.h"
 #include "llvm/Support/Compiler.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/MathExtras.h"
+#include "llvm/Support/Timer.h"
 #include <algorithm>
 using namespace llvm;
 
@@ -5354,7 +5355,14 @@
 
   // Third, instruction select all of the operations to machine code, adding the
   // code to the MachineBasicBlock.
-  InstructionSelectBasicBlock(DAG);
+  InstructionSelect(DAG);
+
+  // Emit machine code to BB.  This can change 'BB' to the last block being 
+  // inserted into.
+  ScheduleAndEmitDAG(DAG);
+
+  // Perform target specific isel post processing.
+  InstructionSelectPostProcessing(DAG);
   
   DOUT << "Selected machine code:\n";
   DEBUG(BB->dump());
diff --git a/lib/Target/ARM/ARMISelDAGToDAG.cpp b/lib/Target/ARM/ARMISelDAGToDAG.cpp
index eaa16fc..34f6cb9 100644
--- a/lib/Target/ARM/ARMISelDAGToDAG.cpp
+++ b/lib/Target/ARM/ARMISelDAGToDAG.cpp
@@ -54,7 +54,7 @@
   } 
   
   SDNode *Select(SDOperand Op);
-  virtual void InstructionSelectBasicBlock(SelectionDAG &DAG);
+  virtual void InstructionSelect(SelectionDAG &DAG);
   bool SelectAddrMode2(SDOperand Op, SDOperand N, SDOperand &Base,
                        SDOperand &Offset, SDOperand &Opc);
   bool SelectAddrMode2Offset(SDOperand Op, SDOperand N,
@@ -91,13 +91,11 @@
 };
 }
 
-void ARMDAGToDAGISel::InstructionSelectBasicBlock(SelectionDAG &DAG) {
+void ARMDAGToDAGISel::InstructionSelect(SelectionDAG &DAG) {
   DEBUG(BB->dump());
 
   DAG.setRoot(SelectRoot(DAG.getRoot()));
   DAG.RemoveDeadNodes();
-
-  ScheduleAndEmitDAG(DAG);
 }
 
 bool ARMDAGToDAGISel::SelectAddrMode2(SDOperand Op, SDOperand N,
diff --git a/lib/Target/Alpha/AlphaISelDAGToDAG.cpp b/lib/Target/Alpha/AlphaISelDAGToDAG.cpp
index c7eefcc..5275f7c 100644
--- a/lib/Target/Alpha/AlphaISelDAGToDAG.cpp
+++ b/lib/Target/Alpha/AlphaISelDAGToDAG.cpp
@@ -161,9 +161,9 @@
     // target-specific node if it hasn't already been changed.
     SDNode *Select(SDOperand Op);
     
-    /// InstructionSelectBasicBlock - This callback is invoked by
+    /// InstructionSelect - This callback is invoked by
     /// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
-    virtual void InstructionSelectBasicBlock(SelectionDAG &DAG);
+    virtual void InstructionSelect(SelectionDAG &DAG);
     
     virtual const char *getPassName() const {
       return "Alpha DAG->DAG Pattern Instruction Selection";
@@ -230,17 +230,14 @@
                                 RA, MVT::i64);
 }
 
-/// InstructionSelectBasicBlock - This callback is invoked by
+/// InstructionSelect - This callback is invoked by
 /// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
-void AlphaDAGToDAGISel::InstructionSelectBasicBlock(SelectionDAG &DAG) {
+void AlphaDAGToDAGISel::InstructionSelect(SelectionDAG &DAG) {
   DEBUG(BB->dump());
   
   // Select target instructions for the DAG.
   DAG.setRoot(SelectRoot(DAG.getRoot()));
   DAG.RemoveDeadNodes();
-  
-  // Emit machine code to BB. 
-  ScheduleAndEmitDAG(DAG);
 }
 
 // Select - Convert the specified operand from a target-independent to a
diff --git a/lib/Target/CellSPU/SPUISelDAGToDAG.cpp b/lib/Target/CellSPU/SPUISelDAGToDAG.cpp
index d0261fd..6bc69ee 100644
--- a/lib/Target/CellSPU/SPUISelDAGToDAG.cpp
+++ b/lib/Target/CellSPU/SPUISelDAGToDAG.cpp
@@ -317,9 +317,9 @@
     return false;
   }
 
-  /// InstructionSelectBasicBlock - This callback is invoked by
+  /// InstructionSelect - This callback is invoked by
   /// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
-  virtual void InstructionSelectBasicBlock(SelectionDAG &DAG);
+  virtual void InstructionSelect(SelectionDAG &DAG);
 
   virtual const char *getPassName() const {
     return "Cell SPU DAG->DAG Pattern Instruction Selection";
@@ -339,19 +339,16 @@
 
 }
 
-/// InstructionSelectBasicBlock - This callback is invoked by
+/// InstructionSelect - This callback is invoked by
 /// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
 void
-SPUDAGToDAGISel::InstructionSelectBasicBlock(SelectionDAG &DAG)
+SPUDAGToDAGISel::InstructionSelect(SelectionDAG &DAG)
 {
   DEBUG(BB->dump());
 
   // Select target instructions for the DAG.
   DAG.setRoot(SelectRoot(DAG.getRoot()));
   DAG.RemoveDeadNodes();
-  
-  // Emit machine code to BB.
-  ScheduleAndEmitDAG(DAG);
 }
 
 /*!
diff --git a/lib/Target/IA64/IA64ISelDAGToDAG.cpp b/lib/Target/IA64/IA64ISelDAGToDAG.cpp
index 0a80653..dcd1fe2 100644
--- a/lib/Target/IA64/IA64ISelDAGToDAG.cpp
+++ b/lib/Target/IA64/IA64ISelDAGToDAG.cpp
@@ -78,9 +78,9 @@
     /// operation.
     bool SelectAddr(SDOperand Addr, SDOperand &Op1, SDOperand &Op2);
 
-    /// InstructionSelectBasicBlock - This callback is invoked by
+    /// InstructionSelect - This callback is invoked by
     /// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
-    virtual void InstructionSelectBasicBlock(SelectionDAG &DAG);
+    virtual void InstructionSelect(SelectionDAG &DAG);
     
     virtual const char *getPassName() const {
       return "IA64 (Itanium) DAG->DAG Instruction Selector";
@@ -94,17 +94,14 @@
   };
 }
 
-/// InstructionSelectBasicBlock - This callback is invoked by
+/// InstructionSelect - This callback is invoked by
 /// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
-void IA64DAGToDAGISel::InstructionSelectBasicBlock(SelectionDAG &DAG) {
+void IA64DAGToDAGISel::InstructionSelect(SelectionDAG &DAG) {
   DEBUG(BB->dump());
 
   // Select target instructions for the DAG.
   DAG.setRoot(SelectRoot(DAG.getRoot()));
   DAG.RemoveDeadNodes();
-  
-  // Emit machine code to BB. 
-  ScheduleAndEmitDAG(DAG);
 }
 
 SDNode *IA64DAGToDAGISel::SelectDIV(SDOperand Op) {
diff --git a/lib/Target/Mips/MipsISelDAGToDAG.cpp b/lib/Target/Mips/MipsISelDAGToDAG.cpp
index 283d693..0c967e2 100644
--- a/lib/Target/Mips/MipsISelDAGToDAG.cpp
+++ b/lib/Target/Mips/MipsISelDAGToDAG.cpp
@@ -66,7 +66,7 @@
         SelectionDAGISel(MipsLowering),
         TM(tm), MipsLowering(*TM.getTargetLowering()) {}
   
-  virtual void InstructionSelectBasicBlock(SelectionDAG &SD);
+  virtual void InstructionSelect(SelectionDAG &SD);
 
   // Pass Name
   virtual const char *getPassName() const {
@@ -100,10 +100,10 @@
 
 }
 
-/// InstructionSelectBasicBlock - This callback is invoked by
+/// InstructionSelect - This callback is invoked by
 /// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
 void MipsDAGToDAGISel::
-InstructionSelectBasicBlock(SelectionDAG &SD) 
+InstructionSelect(SelectionDAG &SD) 
 {
   DEBUG(BB->dump());
   // Codegen the basic block.
@@ -120,9 +120,6 @@
   #endif
 
   SD.RemoveDeadNodes();
-  
-  // Emit machine code to BB. 
-  ScheduleAndEmitDAG(SD);
 }
 
 /// getGlobalBaseReg - Output the instructions required to put the
diff --git a/lib/Target/PIC16/PIC16ISelDAGToDAG.cpp b/lib/Target/PIC16/PIC16ISelDAGToDAG.cpp
index 512893b..325e71e 100644
--- a/lib/Target/PIC16/PIC16ISelDAGToDAG.cpp
+++ b/lib/Target/PIC16/PIC16ISelDAGToDAG.cpp
@@ -61,7 +61,7 @@
         SelectionDAGISel(PIC16Lowering),
         TM(tm), PIC16Lowering(*TM.getTargetLowering()) {}
   
-  virtual void InstructionSelectBasicBlock(SelectionDAG &SD);
+  virtual void InstructionSelect(SelectionDAG &SD);
 
   // Pass Name
   virtual const char *getPassName() const {
@@ -97,9 +97,9 @@
 
 }
 
-/// InstructionSelectBasicBlock - This callback is invoked by
+/// InstructionSelect - This callback is invoked by
 /// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
-void PIC16DAGToDAGISel::InstructionSelectBasicBlock(SelectionDAG &SD) 
+void PIC16DAGToDAGISel::InstructionSelect(SelectionDAG &SD) 
 {
   DEBUG(BB->dump());
   // Codegen the basic block.
@@ -115,9 +115,6 @@
   DOUT << "===== Instruction selection ends:\n";
 
   SD.RemoveDeadNodes();
-  
-  // Emit machine code to BB. 
-  ScheduleAndEmitDAG(SD);
 }
 
 
diff --git a/lib/Target/PowerPC/PPCISelDAGToDAG.cpp b/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
index 45a0831..1dea2ee 100644
--- a/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
+++ b/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
@@ -173,9 +173,9 @@
     SDOperand BuildSDIVSequence(SDNode *N);
     SDOperand BuildUDIVSequence(SDNode *N);
     
-    /// InstructionSelectBasicBlock - This callback is invoked by
+    /// InstructionSelect - This callback is invoked by
     /// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
-    virtual void InstructionSelectBasicBlock(SelectionDAG &DAG);
+    virtual void InstructionSelect(SelectionDAG &DAG);
     
     void InsertVRSaveCode(Function &Fn);
 
@@ -201,17 +201,14 @@
   };
 }
 
-/// InstructionSelectBasicBlock - This callback is invoked by
+/// InstructionSelect - This callback is invoked by
 /// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
-void PPCDAGToDAGISel::InstructionSelectBasicBlock(SelectionDAG &DAG) {
+void PPCDAGToDAGISel::InstructionSelect(SelectionDAG &DAG) {
   DEBUG(BB->dump());
 
   // Select target instructions for the DAG.
   DAG.setRoot(SelectRoot(DAG.getRoot()));
   DAG.RemoveDeadNodes();
-  
-  // Emit machine code to BB.
-  ScheduleAndEmitDAG(DAG);
 }
 
 /// InsertVRSaveCode - Once the entire function has been instruction selected,
diff --git a/lib/Target/Sparc/SparcISelDAGToDAG.cpp b/lib/Target/Sparc/SparcISelDAGToDAG.cpp
index 3ef27dd..50690ca 100644
--- a/lib/Target/Sparc/SparcISelDAGToDAG.cpp
+++ b/lib/Target/Sparc/SparcISelDAGToDAG.cpp
@@ -47,9 +47,9 @@
   bool SelectADDRri(SDOperand Op, SDOperand N, SDOperand &Base,
                     SDOperand &Offset);
   
-  /// InstructionSelectBasicBlock - This callback is invoked by
+  /// InstructionSelect - This callback is invoked by
   /// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
-  virtual void InstructionSelectBasicBlock(SelectionDAG &DAG);
+  virtual void InstructionSelect(SelectionDAG &DAG);
   
   virtual const char *getPassName() const {
     return "SPARC DAG->DAG Pattern Instruction Selection";
@@ -60,17 +60,14 @@
 };
 }  // end anonymous namespace
 
-/// InstructionSelectBasicBlock - This callback is invoked by
+/// InstructionSelect - This callback is invoked by
 /// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
-void SparcDAGToDAGISel::InstructionSelectBasicBlock(SelectionDAG &DAG) {
+void SparcDAGToDAGISel::InstructionSelect(SelectionDAG &DAG) {
   DEBUG(BB->dump());
   
   // Select target instructions for the DAG.
   DAG.setRoot(SelectRoot(DAG.getRoot()));
   DAG.RemoveDeadNodes();
-  
-  // Emit machine code to BB. 
-  ScheduleAndEmitDAG(DAG);
 }
 
 bool SparcDAGToDAGISel::SelectADDRri(SDOperand Op, SDOperand Addr,
diff --git a/lib/Target/X86/X86ISelDAGToDAG.cpp b/lib/Target/X86/X86ISelDAGToDAG.cpp
index 3a4496f..895c2cf 100644
--- a/lib/Target/X86/X86ISelDAGToDAG.cpp
+++ b/lib/Target/X86/X86ISelDAGToDAG.cpp
@@ -32,7 +32,6 @@
 #include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/CodeGen/SelectionDAGISel.h"
 #include "llvm/Target/TargetMachine.h"
-#include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/MathExtras.h"
@@ -111,6 +110,10 @@
     /// base register.
     unsigned GlobalBaseReg;
 
+    /// CurBB - Current BB being isel'd.
+    ///
+    MachineBasicBlock *CurBB;
+
   public:
     X86DAGToDAGISel(X86TargetMachine &tm, bool fast)
       : SelectionDAGISel(X86Lowering),
@@ -128,9 +131,13 @@
       return "X86 DAG->DAG Instruction Selection";
     }
 
-    /// InstructionSelectBasicBlock - This callback is invoked by
+    /// InstructionSelect - This callback is invoked by
     /// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
-    virtual void InstructionSelectBasicBlock(SelectionDAG &DAG);
+    virtual void InstructionSelect(SelectionDAG &DAG);
+
+    /// InstructionSelectPostProcessing - Post processing of selected and
+    /// scheduled basic blocks.
+    virtual void InstructionSelectPostProcessing(SelectionDAG &DAG);
 
     virtual void EmitFunctionEntryCode(Function &Fn, MachineFunction &MF);
 
@@ -554,10 +561,10 @@
 
 /// InstructionSelectBasicBlock - This callback is invoked by SelectionDAGISel
 /// when it has created a SelectionDAG for us to codegen.
-void X86DAGToDAGISel::InstructionSelectBasicBlock(SelectionDAG &DAG) {
-  DEBUG(BB->dump());
-  MachineFunction::iterator FirstMBB = BB;
+void X86DAGToDAGISel::InstructionSelect(SelectionDAG &DAG) {
+  CurBB = BB;  // BB can change as result of isel.
 
+  DEBUG(BB->dump());
   if (!FastISel)
     PreprocessForRMW(DAG);
 
@@ -575,11 +582,9 @@
 #endif
 
   DAG.RemoveDeadNodes();
+}
 
-  // Emit machine code to BB.  This can change 'BB' to the last block being 
-  // inserted into.
-  ScheduleAndEmitDAG(DAG);
-  
+void X86DAGToDAGISel::InstructionSelectPostProcessing(SelectionDAG &DAG) {
   // If we are emitting FP stack code, scan the basic block to determine if this
   // block defines any FP values.  If so, put an FP_REG_KILL instruction before
   // the terminator of the block.
@@ -592,7 +597,7 @@
 
   // Scan all of the machine instructions in these MBBs, checking for FP
   // stores.  (RFP32 and RFP64 will not exist in SSE mode, but RFP80 might.)
-  MachineFunction::iterator MBBI = FirstMBB;
+  MachineFunction::iterator MBBI = CurBB;
   MachineFunction::iterator EndMBB = BB; ++EndMBB;
   for (; MBBI != EndMBB; ++MBBI) {
     MachineBasicBlock *MBB = MBBI;