Use const qualifiers with TargetLowering. This eliminates several

const_casts, and it reinforces the design of the Target classes being
immutable.

SelectionDAGISel::IsLegalToFold is now a static member function, because
PIC16 uses it in an unconventional way. There is more room for API
cleanup here.

And PIC16's AsmPrinter no longer uses TargetLowering.

llvm-svn: 101635

4 files changed, 21 insertions, 19 deletions

diff --git a/llvm/lib/Target/Blackfin/BlackfinISelDAGToDAG.cpp b/llvm/lib/Target/Blackfin/BlackfinISelDAGToDAG.cpp
index c8d71aabd1b..b4da96cba59 100644
--- a/llvm/lib/Target/Blackfin/BlackfinISelDAGToDAG.cpp
+++ b/llvm/lib/Target/Blackfin/BlackfinISelDAGToDAG.cpp
@@ -12,7 +12,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "Blackfin.h"
-#include "BlackfinISelLowering.h"
 #include "BlackfinTargetMachine.h"
 #include "BlackfinRegisterInfo.h"
 #include "llvm/Intrinsics.h"
diff --git a/llvm/lib/Target/Blackfin/BlackfinISelLowering.cpp b/llvm/lib/Target/Blackfin/BlackfinISelLowering.cpp
index 3835a970473..adf21188187 100644
--- a/llvm/lib/Target/Blackfin/BlackfinISelLowering.cpp
+++ b/llvm/lib/Target/Blackfin/BlackfinISelLowering.cpp
@@ -139,7 +139,7 @@ MVT::SimpleValueType BlackfinTargetLowering::getSetCCResultType(EVT VT) const {
 }
 
 SDValue BlackfinTargetLowering::LowerGlobalAddress(SDValue Op,
-                                                   SelectionDAG &DAG) {
+                                                   SelectionDAG &DAG) const {
   DebugLoc DL = Op.getDebugLoc();
   const GlobalValue *GV = cast<GlobalAddressSDNode>(Op)->getGlobal();
 
@@ -147,7 +147,8 @@ SDValue BlackfinTargetLowering::LowerGlobalAddress(SDValue Op,
   return DAG.getNode(BFISD::Wrapper, DL, MVT::i32, Op);
 }
 
-SDValue BlackfinTargetLowering::LowerJumpTable(SDValue Op, SelectionDAG &DAG) {
+SDValue BlackfinTargetLowering::LowerJumpTable(SDValue Op,
+                                               SelectionDAG &DAG) const {
   DebugLoc DL = Op.getDebugLoc();
   int JTI = cast<JumpTableSDNode>(Op)->getIndex();
 
@@ -161,7 +162,8 @@ BlackfinTargetLowering::LowerFormalArguments(SDValue Chain,
                                             const SmallVectorImpl<ISD::InputArg>
                                                &Ins,
                                              DebugLoc dl, SelectionDAG &DAG,
-                                             SmallVectorImpl<SDValue> &InVals) {
+                                             SmallVectorImpl<SDValue> &InVals)
+                                               const {
 
   MachineFunction &MF = DAG.getMachineFunction();
   MachineFrameInfo *MFI = MF.getFrameInfo();
@@ -218,7 +220,7 @@ SDValue
 BlackfinTargetLowering::LowerReturn(SDValue Chain,
                                     CallingConv::ID CallConv, bool isVarArg,
                                     const SmallVectorImpl<ISD::OutputArg> &Outs,
-                                    DebugLoc dl, SelectionDAG &DAG) {
+                                    DebugLoc dl, SelectionDAG &DAG) const {
 
   // CCValAssign - represent the assignment of the return value to locations.
   SmallVector<CCValAssign, 16> RVLocs;
@@ -278,7 +280,7 @@ BlackfinTargetLowering::LowerCall(SDValue Chain, SDValue Callee,
                                   const SmallVectorImpl<ISD::OutputArg> &Outs,
                                   const SmallVectorImpl<ISD::InputArg> &Ins,
                                   DebugLoc dl, SelectionDAG &DAG,
-                                  SmallVectorImpl<SDValue> &InVals) {
+                                  SmallVectorImpl<SDValue> &InVals) const {
   // Blackfin target does not yet support tail call optimization.
   isTailCall = false;
 
@@ -414,7 +416,7 @@ BlackfinTargetLowering::LowerCall(SDValue Chain, SDValue Callee,
 
 // Expansion of ADDE / SUBE. This is a bit involved since blackfin doesn't have
 // add-with-carry instructions.
-SDValue BlackfinTargetLowering::LowerADDE(SDValue Op, SelectionDAG &DAG) {
+SDValue BlackfinTargetLowering::LowerADDE(SDValue Op, SelectionDAG &DAG) const {
   // Operands: lhs, rhs, carry-in (AC0 flag)
   // Results: sum, carry-out (AC0 flag)
   DebugLoc dl = Op.getDebugLoc();
@@ -448,7 +450,8 @@ SDValue BlackfinTargetLowering::LowerADDE(SDValue Op, SelectionDAG &DAG) {
   return DAG.getMergeValues(ops, 2, dl);
 }
 
-SDValue BlackfinTargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) {
+SDValue BlackfinTargetLowering::LowerOperation(SDValue Op,
+                                               SelectionDAG &DAG) const {
   switch (Op.getOpcode()) {
   default:
     Op.getNode()->dump();
@@ -468,7 +471,7 @@ SDValue BlackfinTargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) {
 void
 BlackfinTargetLowering::ReplaceNodeResults(SDNode *N,
                                            SmallVectorImpl<SDValue> &Results,
-                                           SelectionDAG &DAG) {
+                                           SelectionDAG &DAG) const {
   DebugLoc dl = N->getDebugLoc();
   switch (N->getOpcode()) {
   default:
diff --git a/llvm/lib/Target/Blackfin/BlackfinISelLowering.h b/llvm/lib/Target/Blackfin/BlackfinISelLowering.h
index 8435c2dcd6e..a7842482687 100644
--- a/llvm/lib/Target/Blackfin/BlackfinISelLowering.h
+++ b/llvm/lib/Target/Blackfin/BlackfinISelLowering.h
@@ -33,10 +33,10 @@ namespace llvm {
   public:
     BlackfinTargetLowering(TargetMachine &TM);
     virtual MVT::SimpleValueType getSetCCResultType(EVT VT) const;
-    virtual SDValue LowerOperation(SDValue Op, SelectionDAG &DAG);
+    virtual SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const;
     virtual void ReplaceNodeResults(SDNode *N,
                                     SmallVectorImpl<SDValue> &Results,
-                                    SelectionDAG &DAG);
+                                    SelectionDAG &DAG) const;
 
     ConstraintType getConstraintType(const std::string &Constraint) const;
     std::pair<unsigned, const TargetRegisterClass*>
@@ -49,29 +49,29 @@ namespace llvm {
     unsigned getFunctionAlignment(const Function *F) const;
 
   private:
-    SDValue LowerGlobalAddress(SDValue Op, SelectionDAG &DAG);
-    SDValue LowerJumpTable(SDValue Op, SelectionDAG &DAG);
-    SDValue LowerADDE(SDValue Op, SelectionDAG &DAG);
+    SDValue LowerGlobalAddress(SDValue Op, SelectionDAG &DAG) const;
+    SDValue LowerJumpTable(SDValue Op, SelectionDAG &DAG) const;
+    SDValue LowerADDE(SDValue Op, SelectionDAG &DAG) const;
 
     virtual SDValue
       LowerFormalArguments(SDValue Chain,
                            CallingConv::ID CallConv, bool isVarArg,
                            const SmallVectorImpl<ISD::InputArg> &Ins,
                            DebugLoc dl, SelectionDAG &DAG,
-                           SmallVectorImpl<SDValue> &InVals);
+                           SmallVectorImpl<SDValue> &InVals) const;
     virtual SDValue
       LowerCall(SDValue Chain, SDValue Callee,
                 CallingConv::ID CallConv, bool isVarArg, bool &isTailCall,
                 const SmallVectorImpl<ISD::OutputArg> &Outs,
                 const SmallVectorImpl<ISD::InputArg> &Ins,
                 DebugLoc dl, SelectionDAG &DAG,
-                SmallVectorImpl<SDValue> &InVals);
+                SmallVectorImpl<SDValue> &InVals) const;
 
     virtual SDValue
       LowerReturn(SDValue Chain,
                   CallingConv::ID CallConv, bool isVarArg,
                   const SmallVectorImpl<ISD::OutputArg> &Outs,
-                  DebugLoc dl, SelectionDAG &DAG);
+                  DebugLoc dl, SelectionDAG &DAG) const;
   };
 } // end namespace llvm
 
diff --git a/llvm/lib/Target/Blackfin/BlackfinTargetMachine.h b/llvm/lib/Target/Blackfin/BlackfinTargetMachine.h
index a14052bc4db..07e73944143 100644
--- a/llvm/lib/Target/Blackfin/BlackfinTargetMachine.h
+++ b/llvm/lib/Target/Blackfin/BlackfinTargetMachine.h
@@ -43,8 +43,8 @@ namespace llvm {
     virtual const BlackfinRegisterInfo *getRegisterInfo() const {
       return &InstrInfo.getRegisterInfo();
     }
-    virtual BlackfinTargetLowering* getTargetLowering() const {
-      return const_cast<BlackfinTargetLowering*>(&TLInfo);
+    virtual const BlackfinTargetLowering* getTargetLowering() const {
+      return &TLInfo;
     }
     virtual const TargetData *getTargetData() const { return &DataLayout; }
     virtual bool addInstSelector(PassManagerBase &PM,