Added a way for TargetLowering to specify what values can be used as the
scale component of the target addressing mode.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26802 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/Target/TargetLowering.h b/include/llvm/Target/TargetLowering.h
index 0ec98a2..2f950b0 100644
--- a/include/llvm/Target/TargetLowering.h
+++ b/include/llvm/Target/TargetLowering.h
@@ -560,15 +560,6 @@
   virtual bool isOperandValidForConstraint(SDOperand Op, char ConstraintLetter);
   
   //===--------------------------------------------------------------------===//
-  // Loop Strength Reduction hooks
-  //
-  
-  /// isLegalAddressImmediate - Return true if the integer value or GlobalValue
-  /// can be used as the offset of the target addressing mode.
-  virtual bool isLegalAddressImmediate(int64_t V) const;
-  virtual bool isLegalAddressImmediate(GlobalValue *GV) const;
-  
-  //===--------------------------------------------------------------------===//
   // Scheduler hooks
   //
   
@@ -580,6 +571,34 @@
   virtual MachineBasicBlock *InsertAtEndOfBasicBlock(MachineInstr *MI,
                                                      MachineBasicBlock *MBB);
 
+  //===--------------------------------------------------------------------===//
+  // Loop Strength Reduction hooks
+  //
+  
+  /// isLegalAddressImmediate - Return true if the integer value or GlobalValue
+  /// can be used as the offset of the target addressing mode.
+  virtual bool isLegalAddressImmediate(int64_t V) const;
+  virtual bool isLegalAddressImmediate(GlobalValue *GV) const;
+
+  typedef std::vector<unsigned>::const_iterator legal_am_scale_iterator;
+  legal_am_scale_iterator legal_am_scale_begin() const {
+    return LegalAddressScales.begin();
+  }
+  legal_am_scale_iterator legal_am_scale_end() const {
+    return LegalAddressScales.end();
+  }
+
+protected:
+  /// addLegalAddressScale - Add a integer (> 1) value which can be used as
+  /// scale in the target addressing mode. Note: the ordering matters so the
+  /// least efficient ones should be entered first.
+  void addLegalAddressScale(unsigned Scale) {
+    LegalAddressScales.push_back(Scale);
+  }
+
+private:
+  std::vector<unsigned> LegalAddressScales;
+  
 private:
   TargetMachine &TM;
   const TargetData &TD;
diff --git a/lib/Target/PowerPC/PPCTargetMachine.cpp b/lib/Target/PowerPC/PPCTargetMachine.cpp
index 041eddf..8985a43 100644
--- a/lib/Target/PowerPC/PPCTargetMachine.cpp
+++ b/lib/Target/PowerPC/PPCTargetMachine.cpp
@@ -84,7 +84,7 @@
   if (FileType != TargetMachine::AssemblyFile) return true;
   
   // Run loop strength reduction before anything else.
-  if (!Fast) PM.add(createLoopStrengthReducePass(1, &TLInfo));
+  if (!Fast) PM.add(createLoopStrengthReducePass(&TLInfo));
 
   // FIXME: Implement efficient support for garbage collection intrinsics.
   PM.add(createLowerGCPass());
@@ -138,7 +138,7 @@
   TM.setRelocationModel(Reloc::DynamicNoPIC);
 
   // Run loop strength reduction before anything else.
-  PM.add(createLoopStrengthReducePass(1, TM.getTargetLowering()));
+  PM.add(createLoopStrengthReducePass(TM.getTargetLowering()));
 
   // FIXME: Implement efficient support for garbage collection intrinsics.
   PM.add(createLowerGCPass());
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index bf0d6d8..148c7f8 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -49,6 +49,16 @@
   setSchedulingPreference(SchedulingForRegPressure);
   setShiftAmountFlavor(Mask);   // shl X, 32 == shl X, 0
   setStackPointerRegisterToSaveRestore(X86::ESP);
+
+  // Add legal addressing mode scale values.
+  addLegalAddressScale(8);
+  addLegalAddressScale(4);
+  addLegalAddressScale(2);
+  // Enter the ones which require both scale + index last. These are more
+  // expensive.
+  addLegalAddressScale(9);
+  addLegalAddressScale(5);
+  addLegalAddressScale(3);
   
   // Set up the register classes.
   addRegisterClass(MVT::i8, X86::R8RegisterClass);
diff --git a/lib/Target/X86/X86TargetMachine.cpp b/lib/Target/X86/X86TargetMachine.cpp
index 2de8cc0..3d5a6f8 100644
--- a/lib/Target/X86/X86TargetMachine.cpp
+++ b/lib/Target/X86/X86TargetMachine.cpp
@@ -97,7 +97,7 @@
       FileType != TargetMachine::ObjectFile) return true;
 
   // Run loop strength reduction before anything else.
-  if (EnableX86LSR) PM.add(createLoopStrengthReducePass(1, &TLInfo));
+  if (EnableX86LSR) PM.add(createLoopStrengthReducePass(&TLInfo));
 
   // FIXME: Implement efficient support for garbage collection intrinsics.
   PM.add(createLowerGCPass());
@@ -166,7 +166,7 @@
 
   // Run loop strength reduction before anything else.
   if (EnableX86LSR)
-    PM.add(createLoopStrengthReducePass(1, TM.getTargetLowering()));
+    PM.add(createLoopStrengthReducePass(TM.getTargetLowering()));
 
   // FIXME: Implement efficient support for garbage collection intrinsics.
   PM.add(createLowerGCPass());