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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101635 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 27 insertions, 25 deletions

diff --git a/lib/Target/MBlaze/MBlazeISelDAGToDAG.cpp b/lib/Target/MBlaze/MBlazeISelDAGToDAG.cpp
index 7e59c4a..c7cd5f4 100644
--- a/lib/Target/MBlaze/MBlazeISelDAGToDAG.cpp
+++ b/lib/Target/MBlaze/MBlazeISelDAGToDAG.cpp
@@ -13,7 +13,6 @@
 
 #define DEBUG_TYPE "mblaze-isel"
 #include "MBlaze.h"
-#include "MBlazeISelLowering.h"
 #include "MBlazeMachineFunction.h"
 #include "MBlazeRegisterInfo.h"
 #include "MBlazeSubtarget.h"
diff --git a/lib/Target/MBlaze/MBlazeISelLowering.cpp b/lib/Target/MBlaze/MBlazeISelLowering.cpp
index 117a1b6..f527a2f 100644
--- a/lib/Target/MBlaze/MBlazeISelLowering.cpp
+++ b/lib/Target/MBlaze/MBlazeISelLowering.cpp
@@ -185,7 +185,8 @@ unsigned MBlazeTargetLowering::getFunctionAlignment(const Function *) const {
   return 2;
 }
 
-SDValue MBlazeTargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) {
+SDValue MBlazeTargetLowering::LowerOperation(SDValue Op,
+                                             SelectionDAG &DAG) const {
   switch (Op.getOpcode())
   {
     case ISD::ConstantPool:       return LowerConstantPool(Op, DAG);
@@ -387,7 +388,8 @@ EmitInstrWithCustomInserter(MachineInstr *MI, MachineBasicBlock *BB,
 //===----------------------------------------------------------------------===//
 //
 
-SDValue MBlazeTargetLowering::LowerSELECT_CC(SDValue Op, SelectionDAG &DAG) {
+SDValue MBlazeTargetLowering::LowerSELECT_CC(SDValue Op,
+                                             SelectionDAG &DAG) const {
   SDValue LHS = Op.getOperand(0);
   SDValue RHS = Op.getOperand(1);
   SDValue TrueVal = Op.getOperand(2);
@@ -409,7 +411,7 @@ SDValue MBlazeTargetLowering::LowerSELECT_CC(SDValue Op, SelectionDAG &DAG) {
 }
 
 SDValue MBlazeTargetLowering::
-LowerGlobalAddress(SDValue Op, SelectionDAG &DAG) {
+LowerGlobalAddress(SDValue Op, SelectionDAG &DAG) const {
   // FIXME there isn't actually debug info here
   DebugLoc dl = Op.getDebugLoc();
   const GlobalValue *GV = cast<GlobalAddressSDNode>(Op)->getGlobal();
@@ -419,13 +421,13 @@ LowerGlobalAddress(SDValue Op, SelectionDAG &DAG) {
 }
 
 SDValue MBlazeTargetLowering::
-LowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) {
+LowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const {
   llvm_unreachable("TLS not implemented for MicroBlaze.");
   return SDValue(); // Not reached
 }
 
 SDValue MBlazeTargetLowering::
-LowerJumpTable(SDValue Op, SelectionDAG &DAG) {
+LowerJumpTable(SDValue Op, SelectionDAG &DAG) const {
   SDValue ResNode;
   SDValue HiPart;
   // FIXME there isn't actually debug info here
@@ -442,7 +444,7 @@ LowerJumpTable(SDValue Op, SelectionDAG &DAG) {
 }
 
 SDValue MBlazeTargetLowering::
-LowerConstantPool(SDValue Op, SelectionDAG &DAG) {
+LowerConstantPool(SDValue Op, SelectionDAG &DAG) const {
   SDValue ResNode;
   EVT PtrVT = Op.getValueType();
   ConstantPoolSDNode *N = cast<ConstantPoolSDNode>(Op);
@@ -455,7 +457,8 @@ LowerConstantPool(SDValue Op, SelectionDAG &DAG) {
   return DAG.getNode(MBlazeISD::Wrap, dl, MVT::i32, CP);
 }
 
-SDValue MBlazeTargetLowering::LowerVASTART(SDValue Op, SelectionDAG &DAG) {
+SDValue MBlazeTargetLowering::LowerVASTART(SDValue Op,
+                                           SelectionDAG &DAG) const {
   MachineFunction &MF = DAG.getMachineFunction();
   MBlazeFunctionInfo *FuncInfo = MF.getInfo<MBlazeFunctionInfo>();
 
@@ -537,7 +540,7 @@ LowerCall(SDValue Chain, SDValue Callee, CallingConv::ID CallConv,
           const SmallVectorImpl<ISD::OutputArg> &Outs,
           const SmallVectorImpl<ISD::InputArg> &Ins,
           DebugLoc dl, SelectionDAG &DAG,
-          SmallVectorImpl<SDValue> &InVals) {
+          SmallVectorImpl<SDValue> &InVals) const {
   // MBlaze does not yet support tail call optimization
   isTailCall = false;
 
@@ -673,7 +676,7 @@ SDValue MBlazeTargetLowering::
 LowerCallResult(SDValue Chain, SDValue InFlag, CallingConv::ID CallConv,
                 bool isVarArg, const SmallVectorImpl<ISD::InputArg> &Ins,
                 DebugLoc dl, SelectionDAG &DAG,
-                SmallVectorImpl<SDValue> &InVals) {
+                SmallVectorImpl<SDValue> &InVals) const {
   // Assign locations to each value returned by this call.
   SmallVector<CCValAssign, 16> RVLocs;
   CCState CCInfo(CallConv, isVarArg, getTargetMachine(),
@@ -703,7 +706,7 @@ SDValue MBlazeTargetLowering::
 LowerFormalArguments(SDValue Chain, CallingConv::ID CallConv, bool isVarArg,
                      const SmallVectorImpl<ISD::InputArg> &Ins,
                      DebugLoc dl, SelectionDAG &DAG,
-                     SmallVectorImpl<SDValue> &InVals) {
+                     SmallVectorImpl<SDValue> &InVals) const {
   MachineFunction &MF = DAG.getMachineFunction();
   MachineFrameInfo *MFI = MF.getFrameInfo();
   MBlazeFunctionInfo *MBlazeFI = MF.getInfo<MBlazeFunctionInfo>();
@@ -845,7 +848,7 @@ LowerFormalArguments(SDValue Chain, CallingConv::ID CallConv, bool isVarArg,
 SDValue MBlazeTargetLowering::
 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 a location
   SmallVector<CCValAssign, 16> RVLocs;
diff --git a/lib/Target/MBlaze/MBlazeISelLowering.h b/lib/Target/MBlaze/MBlazeISelLowering.h
index db8cff0..12ea8e7 100644
--- a/lib/Target/MBlaze/MBlazeISelLowering.h
+++ b/lib/Target/MBlaze/MBlazeISelLowering.h
@@ -67,7 +67,7 @@ namespace llvm {
     explicit MBlazeTargetLowering(MBlazeTargetMachine &TM);
 
     /// LowerOperation - Provide custom lowering hooks for some operations.
-    virtual SDValue LowerOperation(SDValue Op, SelectionDAG &DAG);
+    virtual SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const;
 
     /// getTargetNodeName - This method returns the name of a target specific
     //  DAG node.
@@ -87,22 +87,22 @@ namespace llvm {
                             CallingConv::ID CallConv, bool isVarArg,
                             const SmallVectorImpl<ISD::InputArg> &Ins,
                             DebugLoc dl, SelectionDAG &DAG,
-                            SmallVectorImpl<SDValue> &InVals);
+                            SmallVectorImpl<SDValue> &InVals) const;
 
     // Lower Operand specifics
-    SDValue LowerConstantPool(SDValue Op, SelectionDAG &DAG);
-    SDValue LowerGlobalAddress(SDValue Op, SelectionDAG &DAG);
-    SDValue LowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG);
-    SDValue LowerJumpTable(SDValue Op, SelectionDAG &DAG);
-    SDValue LowerSELECT_CC(SDValue Op, SelectionDAG &DAG);
-    SDValue LowerVASTART(SDValue Op, SelectionDAG &DAG);
+    SDValue LowerConstantPool(SDValue Op, SelectionDAG &DAG) const;
+    SDValue LowerGlobalAddress(SDValue Op, SelectionDAG &DAG) const;
+    SDValue LowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const;
+    SDValue LowerJumpTable(SDValue Op, SelectionDAG &DAG) const;
+    SDValue LowerSELECT_CC(SDValue Op, SelectionDAG &DAG) const;
+    SDValue LowerVASTART(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,
@@ -111,13 +111,13 @@ namespace llvm {
                 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;
 
     virtual MachineBasicBlock *EmitInstrWithCustomInserter(MachineInstr *MI,
                                                          MachineBasicBlock *MBB,
diff --git a/lib/Target/MBlaze/MBlazeTargetMachine.h b/lib/Target/MBlaze/MBlazeTargetMachine.h
index 85c975c..9bf9898 100644
--- a/lib/Target/MBlaze/MBlazeTargetMachine.h
+++ b/lib/Target/MBlaze/MBlazeTargetMachine.h
@@ -51,8 +51,8 @@ namespace llvm {
     virtual const MBlazeRegisterInfo *getRegisterInfo() const
     { return &InstrInfo.getRegisterInfo(); }
 
-    virtual MBlazeTargetLowering   *getTargetLowering() const
-    { return const_cast<MBlazeTargetLowering*>(&TLInfo); }
+    virtual const MBlazeTargetLowering *getTargetLowering() const
+    { return &TLInfo; }
 
     const TargetIntrinsicInfo *getIntrinsicInfo() const
     { return &IntrinsicInfo; }