Pull the LLVM -> DAG lowering code out of the pattern selector so that it
can be shared with the DAG->DAG selector.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22799 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/PowerPC/PPCISelPattern.cpp b/lib/Target/PowerPC/PPCISelPattern.cpp
index 9906446..75f568f 100644
--- a/lib/Target/PowerPC/PPCISelPattern.cpp
+++ b/lib/Target/PowerPC/PPCISelPattern.cpp
@@ -17,6 +17,7 @@
 #include "PowerPCInstrBuilder.h"
 #include "PowerPCInstrInfo.h"
 #include "PPC32TargetMachine.h"
+#include "PPC32ISelLowering.h"
 #include "llvm/Constants.h"
 #include "llvm/Function.h"
 #include "llvm/CodeGen/MachineConstantPool.h"
@@ -26,7 +27,6 @@
 #include "llvm/CodeGen/SelectionDAGISel.h"
 #include "llvm/CodeGen/SSARegMap.h"
 #include "llvm/Target/TargetData.h"
-#include "llvm/Target/TargetLowering.h"
 #include "llvm/Target/TargetOptions.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/MathExtras.h"
@@ -35,489 +35,6 @@
 #include <algorithm>
 using namespace llvm;
 
-
-//===----------------------------------------------------------------------===//
-//  PPC32TargetLowering - PPC32 Implementation of the TargetLowering interface
-namespace {
-  class PPC32TargetLowering : public TargetLowering {
-    int VarArgsFrameIndex;            // FrameIndex for start of varargs area.
-    int ReturnAddrIndex;              // FrameIndex for return slot.
-  public:
-    PPC32TargetLowering(TargetMachine &TM) : TargetLowering(TM) {
-      // Fold away setcc operations if possible.
-      setSetCCIsExpensive();
-
-      // Set up the register classes.
-      addRegisterClass(MVT::i32, PPC32::GPRCRegisterClass);
-      addRegisterClass(MVT::f32, PPC32::FPRCRegisterClass);
-      addRegisterClass(MVT::f64, PPC32::FPRCRegisterClass);
-
-      // PowerPC has no intrinsics for these particular operations
-      setOperationAction(ISD::MEMMOVE, MVT::Other, Expand);
-      setOperationAction(ISD::MEMSET, MVT::Other, Expand);
-      setOperationAction(ISD::MEMCPY, MVT::Other, Expand);
-
-      // PowerPC has an i16 but no i8 (or i1) SEXTLOAD
-      setOperationAction(ISD::SEXTLOAD, MVT::i1, Expand);
-      setOperationAction(ISD::SEXTLOAD, MVT::i8, Expand);
-
-      // PowerPC has no SREM/UREM instructions
-      setOperationAction(ISD::SREM, MVT::i32, Expand);
-      setOperationAction(ISD::UREM, MVT::i32, Expand);
-
-      // We don't support sin/cos/sqrt/fmod
-      setOperationAction(ISD::FSIN , MVT::f64, Expand);
-      setOperationAction(ISD::FCOS , MVT::f64, Expand);
-      setOperationAction(ISD::SREM , MVT::f64, Expand);
-      setOperationAction(ISD::FSIN , MVT::f32, Expand);
-      setOperationAction(ISD::FCOS , MVT::f32, Expand);
-      setOperationAction(ISD::SREM , MVT::f32, Expand);
-
-      // If we're enabling GP optimizations, use hardware square root
-      if (!TM.getSubtarget<PPCSubtarget>().isGigaProcessor()) {
-        setOperationAction(ISD::FSQRT, MVT::f64, Expand);
-        setOperationAction(ISD::FSQRT, MVT::f32, Expand);
-      }
-
-      // PowerPC does not have CTPOP or CTTZ
-      setOperationAction(ISD::CTPOP, MVT::i32  , Expand);
-      setOperationAction(ISD::CTTZ , MVT::i32  , Expand);
-      
-      // PowerPC does not have Select
-      setOperationAction(ISD::SELECT, MVT::i32, Expand);
-      setOperationAction(ISD::SELECT, MVT::f32, Expand);
-      setOperationAction(ISD::SELECT, MVT::f64, Expand);
-
-      // PowerPC does not have FP_TO_UINT
-      setOperationAction(ISD::FP_TO_UINT, MVT::i32, Expand);
-      
-      setSetCCResultContents(ZeroOrOneSetCCResult);
-      addLegalFPImmediate(+0.0); // Necessary for FSEL
-      addLegalFPImmediate(-0.0); //
-
-      computeRegisterProperties();
-    }
-
-    /// LowerArguments - This hook must be implemented to indicate how we should
-    /// lower the arguments for the specified function, into the specified DAG.
-    virtual std::vector<SDOperand>
-    LowerArguments(Function &F, SelectionDAG &DAG);
-
-    /// LowerCallTo - This hook lowers an abstract call to a function into an
-    /// actual call.
-    virtual std::pair<SDOperand, SDOperand>
-    LowerCallTo(SDOperand Chain, const Type *RetTy, bool isVarArg, unsigned CC,
-                bool isTailCall, SDOperand Callee, ArgListTy &Args,
-                SelectionDAG &DAG);
-
-    virtual SDOperand LowerVAStart(SDOperand Chain, SDOperand VAListP,
-                                   Value *VAListV, SelectionDAG &DAG);
-
-    virtual std::pair<SDOperand,SDOperand>
-      LowerVAArg(SDOperand Chain, SDOperand VAListP, Value *VAListV,
-                 const Type *ArgTy, SelectionDAG &DAG);
-
-    virtual std::pair<SDOperand, SDOperand>
-    LowerFrameReturnAddress(bool isFrameAddr, SDOperand Chain, unsigned Depth,
-                            SelectionDAG &DAG);
-  };
-}
-
-
-std::vector<SDOperand>
-PPC32TargetLowering::LowerArguments(Function &F, SelectionDAG &DAG) {
-  //
-  // add beautiful description of PPC stack frame format, or at least some docs
-  //
-  MachineFunction &MF = DAG.getMachineFunction();
-  MachineFrameInfo *MFI = MF.getFrameInfo();
-  MachineBasicBlock& BB = MF.front();
-  std::vector<SDOperand> ArgValues;
-
-  // Due to the rather complicated nature of the PowerPC ABI, rather than a
-  // fixed size array of physical args, for the sake of simplicity let the STL
-  // handle tracking them for us.
-  std::vector<unsigned> argVR, argPR, argOp;
-  unsigned ArgOffset = 24;
-  unsigned GPR_remaining = 8;
-  unsigned FPR_remaining = 13;
-  unsigned GPR_idx = 0, FPR_idx = 0;
-  static const unsigned GPR[] = {
-    PPC::R3, PPC::R4, PPC::R5, PPC::R6,
-    PPC::R7, PPC::R8, PPC::R9, PPC::R10,
-  };
-  static const unsigned FPR[] = {
-    PPC::F1, PPC::F2, PPC::F3, PPC::F4, PPC::F5, PPC::F6, PPC::F7,
-    PPC::F8, PPC::F9, PPC::F10, PPC::F11, PPC::F12, PPC::F13
-  };
-
-  // Add DAG nodes to load the arguments...  On entry to a function on PPC,
-  // the arguments start at offset 24, although they are likely to be passed
-  // in registers.
-  for (Function::arg_iterator I = F.arg_begin(), E = F.arg_end(); I != E; ++I) {
-    SDOperand newroot, argt;
-    unsigned ObjSize;
-    bool needsLoad = false;
-    bool ArgLive = !I->use_empty();
-    MVT::ValueType ObjectVT = getValueType(I->getType());
-
-    switch (ObjectVT) {
-    default: assert(0 && "Unhandled argument type!");
-    case MVT::i1:
-    case MVT::i8:
-    case MVT::i16:
-    case MVT::i32:
-      ObjSize = 4;
-      if (!ArgLive) break;
-      if (GPR_remaining > 0) {
-        MF.addLiveIn(GPR[GPR_idx]);
-        argt = newroot = DAG.getCopyFromReg(GPR[GPR_idx], MVT::i32,
-                                            DAG.getRoot());
-        if (ObjectVT != MVT::i32)
-          argt = DAG.getNode(ISD::TRUNCATE, ObjectVT, newroot);
-      } else {
-        needsLoad = true;
-      }
-      break;
-      case MVT::i64: ObjSize = 8;
-      if (!ArgLive) break;
-      if (GPR_remaining > 0) {
-        SDOperand argHi, argLo;
-        MF.addLiveIn(GPR[GPR_idx]);
-        argHi = DAG.getCopyFromReg(GPR[GPR_idx], MVT::i32, DAG.getRoot());
-        // If we have two or more remaining argument registers, then both halves
-        // of the i64 can be sourced from there.  Otherwise, the lower half will
-        // have to come off the stack.  This can happen when an i64 is preceded
-        // by 28 bytes of arguments.
-        if (GPR_remaining > 1) {
-          MF.addLiveIn(GPR[GPR_idx+1]);
-          argLo = DAG.getCopyFromReg(GPR[GPR_idx+1], MVT::i32, argHi);
-        } else {
-          int FI = MFI->CreateFixedObject(4, ArgOffset+4);
-          SDOperand FIN = DAG.getFrameIndex(FI, MVT::i32);
-          argLo = DAG.getLoad(MVT::i32, DAG.getEntryNode(), FIN,
-                              DAG.getSrcValue(NULL));
-        }
-        // Build the outgoing arg thingy
-        argt = DAG.getNode(ISD::BUILD_PAIR, MVT::i64, argLo, argHi);
-        newroot = argLo;
-      } else {
-        needsLoad = true;
-      }
-      break;
-      case MVT::f32:
-      case MVT::f64:
-      ObjSize = (ObjectVT == MVT::f64) ? 8 : 4;
-      if (!ArgLive) break;
-      if (FPR_remaining > 0) {
-        MF.addLiveIn(FPR[FPR_idx]);
-        argt = newroot = DAG.getCopyFromReg(FPR[FPR_idx], ObjectVT,
-                                            DAG.getRoot());
-        --FPR_remaining;
-        ++FPR_idx;
-      } else {
-        needsLoad = true;
-      }
-      break;
-    }
-
-    // We need to load the argument to a virtual register if we determined above
-    // that we ran out of physical registers of the appropriate type
-    if (needsLoad) {
-      unsigned SubregOffset = 0;
-      if (ObjectVT == MVT::i8 || ObjectVT == MVT::i1) SubregOffset = 3;
-      if (ObjectVT == MVT::i16) SubregOffset = 2;
-      int FI = MFI->CreateFixedObject(ObjSize, ArgOffset);
-      SDOperand FIN = DAG.getFrameIndex(FI, MVT::i32);
-      FIN = DAG.getNode(ISD::ADD, MVT::i32, FIN,
-                        DAG.getConstant(SubregOffset, MVT::i32));
-      argt = newroot = DAG.getLoad(ObjectVT, DAG.getEntryNode(), FIN,
-                                   DAG.getSrcValue(NULL));
-    }
-
-    // Every 4 bytes of argument space consumes one of the GPRs available for
-    // argument passing.
-    if (GPR_remaining > 0) {
-      unsigned delta = (GPR_remaining > 1 && ObjSize == 8) ? 2 : 1;
-      GPR_remaining -= delta;
-      GPR_idx += delta;
-    }
-    ArgOffset += ObjSize;
-    if (newroot.Val)
-      DAG.setRoot(newroot.getValue(1));
-
-    ArgValues.push_back(argt);
-  }
-
-  // If the function takes variable number of arguments, make a frame index for
-  // the start of the first vararg value... for expansion of llvm.va_start.
-  if (F.isVarArg()) {
-    VarArgsFrameIndex = MFI->CreateFixedObject(4, ArgOffset);
-    SDOperand FIN = DAG.getFrameIndex(VarArgsFrameIndex, MVT::i32);
-    // If this function is vararg, store any remaining integer argument regs
-    // to their spots on the stack so that they may be loaded by deferencing the
-    // result of va_next.
-    std::vector<SDOperand> MemOps;
-    for (; GPR_remaining > 0; --GPR_remaining, ++GPR_idx) {
-      MF.addLiveIn(GPR[GPR_idx]);
-      SDOperand Val = DAG.getCopyFromReg(GPR[GPR_idx], MVT::i32, DAG.getRoot());
-      SDOperand Store = DAG.getNode(ISD::STORE, MVT::Other, Val.getValue(1),
-                                    Val, FIN, DAG.getSrcValue(NULL));
-      MemOps.push_back(Store);
-      // Increment the address by four for the next argument to store
-      SDOperand PtrOff = DAG.getConstant(4, getPointerTy());
-      FIN = DAG.getNode(ISD::ADD, MVT::i32, FIN, PtrOff);
-    }
-    DAG.setRoot(DAG.getNode(ISD::TokenFactor, MVT::Other, MemOps));
-  }
-
-  // Finally, inform the code generator which regs we return values in.
-  switch (getValueType(F.getReturnType())) {
-  default: assert(0 && "Unknown type!");
-  case MVT::isVoid: break;
-  case MVT::i1:
-  case MVT::i8:
-  case MVT::i16:
-  case MVT::i32:
-    MF.addLiveOut(PPC::R3);
-    break;
-  case MVT::i64:
-    MF.addLiveOut(PPC::R3);
-    MF.addLiveOut(PPC::R4);
-    break;
-  case MVT::f32:
-  case MVT::f64:
-    MF.addLiveOut(PPC::F1);
-    break;
-  }
-
-  return ArgValues;
-}
-
-std::pair<SDOperand, SDOperand>
-PPC32TargetLowering::LowerCallTo(SDOperand Chain,
-                                 const Type *RetTy, bool isVarArg,
-                                 unsigned CallingConv, bool isTailCall,
-                                 SDOperand Callee, ArgListTy &Args,
-                                 SelectionDAG &DAG) {
-  // args_to_use will accumulate outgoing args for the ISD::CALL case in
-  // SelectExpr to use to put the arguments in the appropriate registers.
-  std::vector<SDOperand> args_to_use;
-
-  // Count how many bytes are to be pushed on the stack, including the linkage
-  // area, and parameter passing area.
-  unsigned NumBytes = 24;
-
-  if (Args.empty()) {
-    Chain = DAG.getNode(ISD::CALLSEQ_START, MVT::Other, Chain,
-                        DAG.getConstant(NumBytes, getPointerTy()));
-  } else {
-    for (unsigned i = 0, e = Args.size(); i != e; ++i)
-      switch (getValueType(Args[i].second)) {
-      default: assert(0 && "Unknown value type!");
-      case MVT::i1:
-      case MVT::i8:
-      case MVT::i16:
-      case MVT::i32:
-      case MVT::f32:
-        NumBytes += 4;
-        break;
-      case MVT::i64:
-      case MVT::f64:
-        NumBytes += 8;
-        break;
-      }
-
-    // Just to be safe, we'll always reserve the full 24 bytes of linkage area
-    // plus 32 bytes of argument space in case any called code gets funky on us.
-    // (Required by ABI to support var arg)
-    if (NumBytes < 56) NumBytes = 56;
-
-    // Adjust the stack pointer for the new arguments...
-    // These operations are automatically eliminated by the prolog/epilog pass
-    Chain = DAG.getNode(ISD::CALLSEQ_START, MVT::Other, Chain,
-                        DAG.getConstant(NumBytes, getPointerTy()));
-
-    // Set up a copy of the stack pointer for use loading and storing any
-    // arguments that may not fit in the registers available for argument
-    // passing.
-    SDOperand StackPtr = DAG.getCopyFromReg(PPC::R1, MVT::i32,
-                                            DAG.getEntryNode());
-
-    // Figure out which arguments are going to go in registers, and which in
-    // memory.  Also, if this is a vararg function, floating point operations
-    // must be stored to our stack, and loaded into integer regs as well, if
-    // any integer regs are available for argument passing.
-    unsigned ArgOffset = 24;
-    unsigned GPR_remaining = 8;
-    unsigned FPR_remaining = 13;
-
-    std::vector<SDOperand> MemOps;
-    for (unsigned i = 0, e = Args.size(); i != e; ++i) {
-      // PtrOff will be used to store the current argument to the stack if a
-      // register cannot be found for it.
-      SDOperand PtrOff = DAG.getConstant(ArgOffset, getPointerTy());
-      PtrOff = DAG.getNode(ISD::ADD, MVT::i32, StackPtr, PtrOff);
-      MVT::ValueType ArgVT = getValueType(Args[i].second);
-
-      switch (ArgVT) {
-      default: assert(0 && "Unexpected ValueType for argument!");
-      case MVT::i1:
-      case MVT::i8:
-      case MVT::i16:
-        // Promote the integer to 32 bits.  If the input type is signed use a
-        // sign extend, otherwise use a zero extend.
-        if (Args[i].second->isSigned())
-          Args[i].first =DAG.getNode(ISD::SIGN_EXTEND, MVT::i32, Args[i].first);
-        else
-          Args[i].first =DAG.getNode(ISD::ZERO_EXTEND, MVT::i32, Args[i].first);
-        // FALL THROUGH
-      case MVT::i32:
-        if (GPR_remaining > 0) {
-          args_to_use.push_back(Args[i].first);
-          --GPR_remaining;
-        } else {
-          MemOps.push_back(DAG.getNode(ISD::STORE, MVT::Other, Chain,
-                                       Args[i].first, PtrOff,
-                                       DAG.getSrcValue(NULL)));
-        }
-        ArgOffset += 4;
-        break;
-      case MVT::i64:
-        // If we have one free GPR left, we can place the upper half of the i64
-        // in it, and store the other half to the stack.  If we have two or more
-        // free GPRs, then we can pass both halves of the i64 in registers.
-        if (GPR_remaining > 0) {
-          SDOperand Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, MVT::i32,
-            Args[i].first, DAG.getConstant(1, MVT::i32));
-          SDOperand Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, MVT::i32,
-            Args[i].first, DAG.getConstant(0, MVT::i32));
-          args_to_use.push_back(Hi);
-          --GPR_remaining;
-          if (GPR_remaining > 0) {
-            args_to_use.push_back(Lo);
-            --GPR_remaining;
-          } else {
-            SDOperand ConstFour = DAG.getConstant(4, getPointerTy());
-            PtrOff = DAG.getNode(ISD::ADD, MVT::i32, PtrOff, ConstFour);
-            MemOps.push_back(DAG.getNode(ISD::STORE, MVT::Other, Chain,
-                                         Lo, PtrOff, DAG.getSrcValue(NULL)));
-          }
-        } else {
-          MemOps.push_back(DAG.getNode(ISD::STORE, MVT::Other, Chain,
-                                       Args[i].first, PtrOff,
-                                       DAG.getSrcValue(NULL)));
-        }
-        ArgOffset += 8;
-        break;
-      case MVT::f32:
-      case MVT::f64:
-        if (FPR_remaining > 0) {
-          args_to_use.push_back(Args[i].first);
-          --FPR_remaining;
-          if (isVarArg) {
-            SDOperand Store = DAG.getNode(ISD::STORE, MVT::Other, Chain,
-                                          Args[i].first, PtrOff,
-                                          DAG.getSrcValue(NULL));
-            MemOps.push_back(Store);
-            // Float varargs are always shadowed in available integer registers
-            if (GPR_remaining > 0) {
-              SDOperand Load = DAG.getLoad(MVT::i32, Store, PtrOff,
-                                           DAG.getSrcValue(NULL));
-              MemOps.push_back(Load);
-              args_to_use.push_back(Load);
-              --GPR_remaining;
-            }
-            if (GPR_remaining > 0 && MVT::f64 == ArgVT) {
-              SDOperand ConstFour = DAG.getConstant(4, getPointerTy());
-              PtrOff = DAG.getNode(ISD::ADD, MVT::i32, PtrOff, ConstFour);
-              SDOperand Load = DAG.getLoad(MVT::i32, Store, PtrOff,
-                                           DAG.getSrcValue(NULL));
-              MemOps.push_back(Load);
-              args_to_use.push_back(Load);
-              --GPR_remaining;
-            }
-          } else {
-            // If we have any FPRs remaining, we may also have GPRs remaining.
-            // Args passed in FPRs consume either 1 (f32) or 2 (f64) available
-            // GPRs.
-            if (GPR_remaining > 0) {
-              args_to_use.push_back(DAG.getNode(ISD::UNDEF, MVT::i32));
-              --GPR_remaining;
-            }
-            if (GPR_remaining > 0 && MVT::f64 == ArgVT) {
-              args_to_use.push_back(DAG.getNode(ISD::UNDEF, MVT::i32));
-              --GPR_remaining;
-            }
-          }
-        } else {
-          MemOps.push_back(DAG.getNode(ISD::STORE, MVT::Other, Chain,
-                                       Args[i].first, PtrOff,
-                                       DAG.getSrcValue(NULL)));
-        }
-        ArgOffset += (ArgVT == MVT::f32) ? 4 : 8;
-        break;
-      }
-    }
-    if (!MemOps.empty())
-      Chain = DAG.getNode(ISD::TokenFactor, MVT::Other, MemOps);
-  }
-
-  std::vector<MVT::ValueType> RetVals;
-  MVT::ValueType RetTyVT = getValueType(RetTy);
-  if (RetTyVT != MVT::isVoid)
-    RetVals.push_back(RetTyVT);
-  RetVals.push_back(MVT::Other);
-
-  SDOperand TheCall = SDOperand(DAG.getCall(RetVals,
-                                            Chain, Callee, args_to_use), 0);
-  Chain = TheCall.getValue(RetTyVT != MVT::isVoid);
-  Chain = DAG.getNode(ISD::CALLSEQ_END, MVT::Other, Chain,
-                      DAG.getConstant(NumBytes, getPointerTy()));
-  return std::make_pair(TheCall, Chain);
-}
-
-SDOperand PPC32TargetLowering::LowerVAStart(SDOperand Chain, SDOperand VAListP,
-                                            Value *VAListV, SelectionDAG &DAG) {
-  // vastart just stores the address of the VarArgsFrameIndex slot into the
-  // memory location argument.
-  SDOperand FR = DAG.getFrameIndex(VarArgsFrameIndex, MVT::i32);
-  return DAG.getNode(ISD::STORE, MVT::Other, Chain, FR, VAListP,
-                     DAG.getSrcValue(VAListV));
-}
-
-std::pair<SDOperand,SDOperand>
-PPC32TargetLowering::LowerVAArg(SDOperand Chain,
-                                SDOperand VAListP, Value *VAListV,
-                                const Type *ArgTy, SelectionDAG &DAG) {
-  MVT::ValueType ArgVT = getValueType(ArgTy);
-
-  SDOperand VAList =
-    DAG.getLoad(MVT::i32, Chain, VAListP, DAG.getSrcValue(VAListV));
-  SDOperand Result = DAG.getLoad(ArgVT, Chain, VAList, DAG.getSrcValue(NULL));
-  unsigned Amt;
-  if (ArgVT == MVT::i32 || ArgVT == MVT::f32)
-    Amt = 4;
-  else {
-    assert((ArgVT == MVT::i64 || ArgVT == MVT::f64) &&
-           "Other types should have been promoted for varargs!");
-    Amt = 8;
-  }
-  VAList = DAG.getNode(ISD::ADD, VAList.getValueType(), VAList,
-                      DAG.getConstant(Amt, VAList.getValueType()));
-  Chain = DAG.getNode(ISD::STORE, MVT::Other, Chain,
-                      VAList, VAListP, DAG.getSrcValue(VAListV));
-  return std::make_pair(Result, Chain);
-}
-
-
-std::pair<SDOperand, SDOperand> PPC32TargetLowering::
-LowerFrameReturnAddress(bool isFrameAddress, SDOperand Chain, unsigned Depth,
-                        SelectionDAG &DAG) {
-  assert(0 && "LowerFrameReturnAddress unimplemented");
-  abort();
-}
-
 namespace {
 Statistic<>Recorded("ppc-codegen", "Number of recording ops emitted");
 Statistic<>FusedFP("ppc-codegen", "Number of fused fp operations");