[llvm-commits] CVS: llvm/lib/Target/PowerPC/PPC64ISelPattern.cpp PowerPC.h PowerPCTargetMachine.cpp PPC64ISelSimple.cpp

Nate Begeman natebegeman at mac.com
Tue Apr 5 01:51:27 PDT 2005



Changes in directory llvm/lib/Target/PowerPC:

PPC64ISelPattern.cpp added (r1.1)
PowerPC.h updated: 1.12 -> 1.13
PowerPCTargetMachine.cpp updated: 1.48 -> 1.49
PPC64ISelSimple.cpp (r1.18) removed
---
Log message:

Remove 64 bit simple ISel, it never worked correctly
Add initial (buggy) implementation of 64 bit pattern ISel


---
Diffs of the changes:  (+1769 -2)

 PPC64ISelPattern.cpp     | 1767 +++++++++++++++++++++++++++++++++++++++++++++++
 PowerPC.h                |    2 
 PowerPCTargetMachine.cpp |    2 
 3 files changed, 1769 insertions(+), 2 deletions(-)


Index: llvm/lib/Target/PowerPC/PPC64ISelPattern.cpp
diff -c /dev/null llvm/lib/Target/PowerPC/PPC64ISelPattern.cpp:1.1
*** /dev/null	Tue Apr  5 03:51:25 2005
--- llvm/lib/Target/PowerPC/PPC64ISelPattern.cpp	Tue Apr  5 03:51:15 2005
***************
*** 0 ****
--- 1,1767 ----
+ //===-- PPC32ISelPattern.cpp - A pattern matching inst selector for PPC32 -===//
+ //
+ //                     The LLVM Compiler Infrastructure
+ //
+ // This file was developed by Nate Begeman and is distributed under
+ // the University of Illinois Open Source License. See LICENSE.TXT for details.
+ // 
+ //===----------------------------------------------------------------------===//
+ //
+ // This file defines a pattern matching instruction selector for 32 bit PowerPC.
+ //
+ //===----------------------------------------------------------------------===//
+ 
+ #include "PowerPC.h"
+ #include "PowerPCInstrBuilder.h"
+ #include "PowerPCInstrInfo.h"
+ #include "PPC64RegisterInfo.h"
+ #include "llvm/Constants.h"                   // FIXME: REMOVE
+ #include "llvm/Function.h"
+ #include "llvm/CodeGen/MachineConstantPool.h" // FIXME: REMOVE
+ #include "llvm/CodeGen/MachineFunction.h"
+ #include "llvm/CodeGen/MachineFrameInfo.h"
+ #include "llvm/CodeGen/SelectionDAG.h"
+ #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"
+ #include "llvm/ADT/Statistic.h"
+ #include <set>
+ #include <algorithm>
+ using namespace llvm;
+ 
+ //===----------------------------------------------------------------------===//
+ //  PPC32TargetLowering - PPC32 Implementation of the TargetLowering interface
+ namespace {
+   class PPC64TargetLowering : public TargetLowering {
+     int VarArgsFrameIndex;            // FrameIndex for start of varargs area.
+     int ReturnAddrIndex;              // FrameIndex for return slot.
+   public:
+     PPC64TargetLowering(TargetMachine &TM) : TargetLowering(TM) {
+       // Set up the register classes.
+       addRegisterClass(MVT::i64, PPC64::GPRCRegisterClass);
+       addRegisterClass(MVT::f32, PPC64::FPRCRegisterClass);
+       addRegisterClass(MVT::f64, PPC64::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);
+ 
+       // PPC 64 has i16 and i32 but no i8 (or i1) SEXTLOAD
+       setOperationAction(ISD::SEXTLOAD, MVT::i1, Expand);
+       setOperationAction(ISD::SEXTLOAD, MVT::i8, Expand);
+ 
+       setShiftAmountFlavor(Extend);   // shl X, 32 == 0
+       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,
+                 SDOperand Callee, ArgListTy &Args, SelectionDAG &DAG);
+     
+     virtual std::pair<SDOperand, SDOperand>
+     LowerVAStart(SDOperand Chain, SelectionDAG &DAG);
+     
+     virtual std::pair<SDOperand,SDOperand>
+     LowerVAArgNext(bool isVANext, SDOperand Chain, SDOperand VAList,
+                    const Type *ArgTy, SelectionDAG &DAG);
+ 
+     virtual std::pair<SDOperand, SDOperand>
+     LowerFrameReturnAddress(bool isFrameAddr, SDOperand Chain, unsigned Depth,
+                             SelectionDAG &DAG);
+   };
+ }
+ 
+ 
+ std::vector<SDOperand>
+ PPC64TargetLowering::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;
+     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 (GPR_remaining > 0) {
+         BuildMI(&BB, PPC::IMPLICIT_DEF, 0, 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;
+       // FIXME: can split 64b load between reg/mem if it is last arg in regs
+       if (GPR_remaining > 1) {
+         BuildMI(&BB, PPC::IMPLICIT_DEF, 0, GPR[GPR_idx]);
+         BuildMI(&BB, PPC::IMPLICIT_DEF, 0, GPR[GPR_idx+1]);
+         // Copy the extracted halves into the virtual registers
+         SDOperand argHi = DAG.getCopyFromReg(GPR[GPR_idx], MVT::i32, 
+                                              DAG.getRoot());
+         SDOperand argLo = DAG.getCopyFromReg(GPR[GPR_idx+1], MVT::i32, argHi);
+         // Build the outgoing arg thingy
+         argt = DAG.getNode(ISD::BUILD_PAIR, MVT::i64, argLo, argHi);
+         newroot = argLo;
+       } else {
+         needsLoad = true; 
+       }
+       break;
+       case MVT::f32: ObjSize = 4;
+       case MVT::f64: ObjSize = 8;
+       if (FPR_remaining > 0) {
+         BuildMI(&BB, PPC::IMPLICIT_DEF, 0, 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);
+     }
+     
+     // 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;
+     
+     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) {
+       BuildMI(&BB, PPC::IMPLICIT_DEF, 0, 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);
+       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));
+   }
+ 
+   return ArgValues;
+ }
+ 
+ std::pair<SDOperand, SDOperand>
+ PPC64TargetLowering::LowerCallTo(SDOperand Chain,
+ 				 const Type *RetTy, bool isVarArg,
+          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::ADJCALLSTACKDOWN, 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.
+     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::ADJCALLSTACKDOWN, 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));
+         }
+         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));
+           }
+         } else {
+           MemOps.push_back(DAG.getNode(ISD::STORE, MVT::Other, Chain,
+                                           Args[i].first, PtrOff));
+         }
+         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);
+             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);
+               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);
+               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));
+         }
+         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::ADJCALLSTACKUP, MVT::Other, Chain,
+                       DAG.getConstant(NumBytes, getPointerTy()));
+   return std::make_pair(TheCall, Chain);
+ }
+ 
+ std::pair<SDOperand, SDOperand>
+ PPC64TargetLowering::LowerVAStart(SDOperand Chain, SelectionDAG &DAG) {
+   //vastart just returns the address of the VarArgsFrameIndex slot.
+   return std::make_pair(DAG.getFrameIndex(VarArgsFrameIndex, MVT::i32), Chain);
+ }
+ 
+ std::pair<SDOperand,SDOperand> PPC64TargetLowering::
+ LowerVAArgNext(bool isVANext, SDOperand Chain, SDOperand VAList,
+                const Type *ArgTy, SelectionDAG &DAG) {
+   MVT::ValueType ArgVT = getValueType(ArgTy);
+   SDOperand Result;
+   if (!isVANext) {
+     Result = DAG.getLoad(ArgVT, DAG.getEntryNode(), VAList);
+   } else {
+     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;
+     }
+     Result = DAG.getNode(ISD::ADD, VAList.getValueType(), VAList,
+                          DAG.getConstant(Amt, VAList.getValueType()));
+   }
+   return std::make_pair(Result, Chain);
+ }
+                
+ 
+ std::pair<SDOperand, SDOperand> PPC64TargetLowering::
+ LowerFrameReturnAddress(bool isFrameAddress, SDOperand Chain, unsigned Depth,
+                         SelectionDAG &DAG) {
+   assert(0 && "LowerFrameReturnAddress unimplemented");
+   abort();
+ }
+ 
+ namespace {
+ Statistic<>NotLogic("ppc-codegen", "Number of inverted logical ops");
+ Statistic<>FusedFP("ppc-codegen", "Number of fused fp operations");
+ //===--------------------------------------------------------------------===//
+ /// ISel - PPC32 specific code to select PPC32 machine instructions for
+ /// SelectionDAG operations.
+ //===--------------------------------------------------------------------===//
+ class ISel : public SelectionDAGISel {
+   
+   /// Comment Here.
+   PPC64TargetLowering PPC64Lowering;
+   
+   /// ExprMap - As shared expressions are codegen'd, we keep track of which
+   /// vreg the value is produced in, so we only emit one copy of each compiled
+   /// tree.
+   std::map<SDOperand, unsigned> ExprMap;
+ 
+   unsigned GlobalBaseReg;
+   bool GlobalBaseInitialized;
+   
+ public:
+   ISel(TargetMachine &TM) : SelectionDAGISel(PPC64Lowering), PPC64Lowering(TM) 
+   {}
+   
+   /// runOnFunction - Override this function in order to reset our per-function
+   /// variables.
+   virtual bool runOnFunction(Function &Fn) {
+     // Make sure we re-emit a set of the global base reg if necessary
+     GlobalBaseInitialized = false;
+     return SelectionDAGISel::runOnFunction(Fn);
+   } 
+   
+   /// InstructionSelectBasicBlock - This callback is invoked by
+   /// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
+   virtual void InstructionSelectBasicBlock(SelectionDAG &DAG) {
+     DEBUG(BB->dump());
+     // Codegen the basic block.
+     Select(DAG.getRoot());
+     
+     // Clear state used for selection.
+     ExprMap.clear();
+   }
+   
+   unsigned getGlobalBaseReg();
+   unsigned getConstDouble(double floatVal, unsigned Result);
+   unsigned SelectSetCR0(SDOperand CC);
+   unsigned SelectExpr(SDOperand N);
+   unsigned SelectExprFP(SDOperand N, unsigned Result);
+   void Select(SDOperand N);
+   
+   bool SelectAddr(SDOperand N, unsigned& Reg, int& offset);
+   void SelectBranchCC(SDOperand N);
+ };
+ 
+ /// ExactLog2 - This function solves for (Val == 1 << (N-1)) and returns N.  It
+ /// returns zero when the input is not exactly a power of two.
+ static unsigned ExactLog2(unsigned Val) {
+   if (Val == 0 || (Val & (Val-1))) return 0;
+   unsigned Count = 0;
+   while (Val != 1) {
+     Val >>= 1;
+     ++Count;
+   }
+   return Count;
+ }
+ 
+ /// getImmediateForOpcode - This method returns a value indicating whether
+ /// the ConstantSDNode N can be used as an immediate to Opcode.  The return
+ /// values are either 0, 1 or 2.  0 indicates that either N is not a
+ /// ConstantSDNode, or is not suitable for use by that opcode.  A return value 
+ /// of 1 indicates that the constant may be used in normal immediate form.  A
+ /// return value of 2 indicates that the constant may be used in shifted
+ /// immediate form.  A return value of 3 indicates that log base 2 of the
+ /// constant may be used.
+ ///
+ static unsigned getImmediateForOpcode(SDOperand N, unsigned Opcode,
+                                       unsigned& Imm, bool U = false) {
+   if (N.getOpcode() != ISD::Constant) return 0;
+ 
+   int v = (int)cast<ConstantSDNode>(N)->getSignExtended();
+   
+   switch(Opcode) {
+   default: return 0;
+   case ISD::ADD:
+     if (v <= 32767 && v >= -32768) { Imm = v & 0xFFFF; return 1; }
+     if ((v & 0x0000FFFF) == 0) { Imm = v >> 16; return 2; }
+     break;
+   case ISD::AND:
+   case ISD::XOR:
+   case ISD::OR:
+     if (v >= 0 && v <= 65535) { Imm = v & 0xFFFF; return 1; }
+     if ((v & 0x0000FFFF) == 0) { Imm = v >> 16; return 2; }
+     break;
+   case ISD::MUL:
+   case ISD::SUB:
+     if (v <= 32767 && v >= -32768) { Imm = v & 0xFFFF; return 1; }
+     break;
+   case ISD::SETCC:
+     if (U && (v >= 0 && v <= 65535)) { Imm = v & 0xFFFF; return 1; }
+     if (!U && (v <= 32767 && v >= -32768)) { Imm = v & 0xFFFF; return 1; }
+     break;
+   case ISD::SDIV:
+     if ((Imm = ExactLog2(v))) { return 3; }
+     break;
+   }
+   return 0;
+ }
+ 
+ /// getBCCForSetCC - Returns the PowerPC condition branch mnemonic corresponding
+ /// to Condition.  If the Condition is unordered or unsigned, the bool argument
+ /// U is set to true, otherwise it is set to false.
+ static unsigned getBCCForSetCC(unsigned Condition, bool& U) {
+   U = false;
+   switch (Condition) {
+   default: assert(0 && "Unknown condition!"); abort();
+   case ISD::SETEQ:  return PPC::BEQ;
+   case ISD::SETNE:  return PPC::BNE;
+   case ISD::SETULT: U = true;
+   case ISD::SETLT:  return PPC::BLT;
+   case ISD::SETULE: U = true;
+   case ISD::SETLE:  return PPC::BLE;
+   case ISD::SETUGT: U = true;
+   case ISD::SETGT:  return PPC::BGT;
+   case ISD::SETUGE: U = true;
+   case ISD::SETGE:  return PPC::BGE;
+   }
+   return 0;
+ }
+ 
+ /// IndexedOpForOp - Return the indexed variant for each of the PowerPC load
+ /// and store immediate instructions.
+ static unsigned IndexedOpForOp(unsigned Opcode) {
+   switch(Opcode) {
+   default: assert(0 && "Unknown opcode!"); abort();
+   case PPC::LBZ: return PPC::LBZX;  case PPC::STB: return PPC::STBX;
+   case PPC::LHZ: return PPC::LHZX;  case PPC::STH: return PPC::STHX;
+   case PPC::LHA: return PPC::LHAX;  case PPC::STW: return PPC::STWX;
+   case PPC::LWZ: return PPC::LWZX;  case PPC::STD: return PPC::STDX;
+   case PPC::LD:  return PPC::LDX;   case PPC::STFS: return PPC::STFSX;
+   case PPC::LFS: return PPC::LFSX;  case PPC::STFD: return PPC::STFDX;
+   case PPC::LFD: return PPC::LFDX;
+   }
+   return 0;
+ }
+ }
+ 
+ /// getGlobalBaseReg - Output the instructions required to put the
+ /// base address to use for accessing globals into a register.
+ ///
+ unsigned ISel::getGlobalBaseReg() {
+   if (!GlobalBaseInitialized) {
+     // Insert the set of GlobalBaseReg into the first MBB of the function
+     MachineBasicBlock &FirstMBB = BB->getParent()->front();
+     MachineBasicBlock::iterator MBBI = FirstMBB.begin();
+     GlobalBaseReg = MakeReg(MVT::i64);
+     BuildMI(FirstMBB, MBBI, PPC::MovePCtoLR, 0, PPC::LR);
+     BuildMI(FirstMBB, MBBI, PPC::MFLR, 1, GlobalBaseReg).addReg(PPC::LR);
+     GlobalBaseInitialized = true;
+   }
+   return GlobalBaseReg;
+ }
+ 
+ /// getConstDouble - Loads a floating point value into a register, via the 
+ /// Constant Pool.  Optionally takes a register in which to load the value.
+ unsigned ISel::getConstDouble(double doubleVal, unsigned Result=0) {
+   unsigned Tmp1 = MakeReg(MVT::i32);
+   if (0 == Result) Result = MakeReg(MVT::f64);
+   MachineConstantPool *CP = BB->getParent()->getConstantPool();
+   ConstantFP *CFP = ConstantFP::get(Type::DoubleTy, doubleVal);
+   unsigned CPI = CP->getConstantPoolIndex(CFP);
+   BuildMI(BB, PPC::LOADHiAddr, 2, Tmp1).addReg(getGlobalBaseReg())
+     .addConstantPoolIndex(CPI);
+   BuildMI(BB, PPC::LFD, 2, Result).addConstantPoolIndex(CPI).addReg(Tmp1);
+   return Result;
+ }
+ 
+ unsigned ISel::SelectSetCR0(SDOperand CC) {
+   unsigned Opc, Tmp1, Tmp2;
+   static const unsigned CompareOpcodes[] = 
+     { PPC::FCMPU, PPC::FCMPU, PPC::CMPW, PPC::CMPLW };
+   
+   // If the first operand to the select is a SETCC node, then we can fold it
+   // into the branch that selects which value to return.
+   SetCCSDNode* SetCC = dyn_cast<SetCCSDNode>(CC.Val);
+   if (SetCC && CC.getOpcode() == ISD::SETCC) {
+     bool U;
+     Opc = getBCCForSetCC(SetCC->getCondition(), U);
+     Tmp1 = SelectExpr(SetCC->getOperand(0));
+ 
+     // Pass the optional argument U to getImmediateForOpcode for SETCC,
+     // so that it knows whether the SETCC immediate range is signed or not.
+     if (1 == getImmediateForOpcode(SetCC->getOperand(1), ISD::SETCC, 
+                                    Tmp2, U)) {
+       if (U)
+         BuildMI(BB, PPC::CMPLWI, 2, PPC::CR0).addReg(Tmp1).addImm(Tmp2);
+       else
+         BuildMI(BB, PPC::CMPWI, 2, PPC::CR0).addReg(Tmp1).addSImm(Tmp2);
+     } else {
+       bool IsInteger = MVT::isInteger(SetCC->getOperand(0).getValueType());
+       unsigned CompareOpc = CompareOpcodes[2 * IsInteger + U];
+       Tmp2 = SelectExpr(SetCC->getOperand(1));
+       BuildMI(BB, CompareOpc, 2, PPC::CR0).addReg(Tmp1).addReg(Tmp2);
+     }
+   } else {
+     Tmp1 = SelectExpr(CC);
+     BuildMI(BB, PPC::CMPLWI, 2, PPC::CR0).addReg(Tmp1).addImm(0);
+     Opc = PPC::BNE;
+   }
+   return Opc;
+ }
+ 
+ /// Check to see if the load is a constant offset from a base register
+ bool ISel::SelectAddr(SDOperand N, unsigned& Reg, int& offset)
+ {
+   unsigned imm = 0, opcode = N.getOpcode();
+   if (N.getOpcode() == ISD::ADD) {
+     Reg = SelectExpr(N.getOperand(0));
+     if (1 == getImmediateForOpcode(N.getOperand(1), opcode, imm)) {
+       offset = imm;
+       return false;
+     } 
+     offset = SelectExpr(N.getOperand(1));
+     return true;
+   }
+   Reg = SelectExpr(N);
+   offset = 0;
+   return false;
+ }
+ 
+ void ISel::SelectBranchCC(SDOperand N)
+ {
+   assert(N.getOpcode() == ISD::BRCOND && "Not a BranchCC???");
+   MachineBasicBlock *Dest = 
+     cast<BasicBlockSDNode>(N.getOperand(2))->getBasicBlock();
+ 
+   // Get the MBB we will fall through to so that we can hand it off to the
+   // branch selection pass as an argument to the PPC::COND_BRANCH pseudo op.
+   //ilist<MachineBasicBlock>::iterator It = BB;
+   //MachineBasicBlock *Fallthrough = ++It;
+   
+   Select(N.getOperand(0));  //chain
+   unsigned Opc = SelectSetCR0(N.getOperand(1));
+   // FIXME: Use this once we have something approximating two-way branches
+   // We cannot currently use this in case the ISel hands us something like
+   // BRcc MBBx
+   // BR MBBy
+   // since the fallthrough basic block for the conditional branch does not start
+   // with the unconditional branch (it is skipped over).
+   //BuildMI(BB, PPC::COND_BRANCH, 4).addReg(PPC::CR0).addImm(Opc)
+   //  .addMBB(Dest).addMBB(Fallthrough);
+   BuildMI(BB, Opc, 2).addReg(PPC::CR0).addMBB(Dest);
+   return;
+ }
+ 
+ unsigned ISel::SelectExprFP(SDOperand N, unsigned Result)
+ {
+   unsigned Tmp1, Tmp2, Tmp3;
+   unsigned Opc = 0;
+   SDNode *Node = N.Val;
+   MVT::ValueType DestType = N.getValueType();
+   unsigned opcode = N.getOpcode();
+ 
+   switch (opcode) {
+   default:
+     Node->dump();
+     assert(0 && "Node not handled!\n");
+ 
+   case ISD::SELECT: {
+     // Attempt to generate FSEL.  We can do this whenever we have an FP result,
+     // and an FP comparison in the SetCC node.
+     SetCCSDNode* SetCC = dyn_cast<SetCCSDNode>(N.getOperand(0).Val);
+     if (SetCC && N.getOperand(0).getOpcode() == ISD::SETCC &&
+         !MVT::isInteger(SetCC->getOperand(0).getValueType()) &&
+         SetCC->getCondition() != ISD::SETEQ &&
+         SetCC->getCondition() != ISD::SETNE) {
+       MVT::ValueType VT = SetCC->getOperand(0).getValueType();
+       Tmp1 = SelectExpr(SetCC->getOperand(0));   // Val to compare against
+       unsigned TV = SelectExpr(N.getOperand(1)); // Use if TRUE
+       unsigned FV = SelectExpr(N.getOperand(2)); // Use if FALSE
+       
+       ConstantFPSDNode *CN = dyn_cast<ConstantFPSDNode>(SetCC->getOperand(1));
+       if (CN && (CN->isExactlyValue(-0.0) || CN->isExactlyValue(0.0))) {
+         switch(SetCC->getCondition()) {
+         default: assert(0 && "Invalid FSEL condition"); abort();
+         case ISD::SETULT:
+         case ISD::SETLT:
+           BuildMI(BB, PPC::FSEL, 3, Result).addReg(Tmp1).addReg(FV).addReg(TV);
+           return Result;
+         case ISD::SETUGE:
+         case ISD::SETGE:
+           BuildMI(BB, PPC::FSEL, 3, Result).addReg(Tmp1).addReg(TV).addReg(FV);
+           return Result;
+         case ISD::SETUGT:
+         case ISD::SETGT: {
+           Tmp2 = MakeReg(VT);
+           BuildMI(BB, PPC::FNEG, 1, Tmp2).addReg(Tmp1);
+           BuildMI(BB, PPC::FSEL, 3, Result).addReg(Tmp2).addReg(FV).addReg(TV);
+           return Result;
+         }
+         case ISD::SETULE:
+         case ISD::SETLE: {
+           Tmp2 = MakeReg(VT);
+           BuildMI(BB, PPC::FNEG, 1, Tmp2).addReg(Tmp1);
+           BuildMI(BB, PPC::FSEL, 3, Result).addReg(Tmp2).addReg(TV).addReg(FV);
+           return Result;
+         }
+         }
+       } else {
+         Opc = (MVT::f64 == VT) ? PPC::FSUB : PPC::FSUBS;
+         Tmp2 = SelectExpr(SetCC->getOperand(1));
+         Tmp3 =  MakeReg(VT);
+         switch(SetCC->getCondition()) {
+         default: assert(0 && "Invalid FSEL condition"); abort();
+         case ISD::SETULT:
+         case ISD::SETLT:
+           BuildMI(BB, Opc, 2, Tmp3).addReg(Tmp1).addReg(Tmp2);
+           BuildMI(BB, PPC::FSEL, 3, Result).addReg(Tmp3).addReg(FV).addReg(TV);
+           return Result;
+         case ISD::SETUGE:
+         case ISD::SETGE:
+           BuildMI(BB, Opc, 2, Tmp3).addReg(Tmp1).addReg(Tmp2);
+           BuildMI(BB, PPC::FSEL, 3, Result).addReg(Tmp3).addReg(TV).addReg(FV);
+           return Result;
+         case ISD::SETUGT:
+         case ISD::SETGT:
+           BuildMI(BB, Opc, 2, Tmp3).addReg(Tmp2).addReg(Tmp1);
+           BuildMI(BB, PPC::FSEL, 3, Result).addReg(Tmp3).addReg(FV).addReg(TV);
+           return Result;
+         case ISD::SETULE:
+         case ISD::SETLE:
+           BuildMI(BB, Opc, 2, Tmp3).addReg(Tmp2).addReg(Tmp1);
+           BuildMI(BB, PPC::FSEL, 3, Result).addReg(Tmp3).addReg(TV).addReg(FV);
+           return Result;
+         }
+       }
+       assert(0 && "Should never get here");
+       return 0;
+     }
+     
+     unsigned TrueValue = SelectExpr(N.getOperand(1)); //Use if TRUE
+     unsigned FalseValue = SelectExpr(N.getOperand(2)); //Use if FALSE
+     Opc = SelectSetCR0(N.getOperand(0));
+ 
+     // Create an iterator with which to insert the MBB for copying the false 
+     // value and the MBB to hold the PHI instruction for this SetCC.
+     MachineBasicBlock *thisMBB = BB;
+     const BasicBlock *LLVM_BB = BB->getBasicBlock();
+     ilist<MachineBasicBlock>::iterator It = BB;
+     ++It;
+ 
+     //  thisMBB:
+     //  ...
+     //   TrueVal = ...
+     //   cmpTY cr0, r1, r2
+     //   bCC copy1MBB
+     //   fallthrough --> copy0MBB
+     MachineBasicBlock *copy0MBB = new MachineBasicBlock(LLVM_BB);
+     MachineBasicBlock *sinkMBB = new MachineBasicBlock(LLVM_BB);
+     BuildMI(BB, Opc, 2).addReg(PPC::CR0).addMBB(sinkMBB);
+     MachineFunction *F = BB->getParent();
+     F->getBasicBlockList().insert(It, copy0MBB);
+     F->getBasicBlockList().insert(It, sinkMBB);
+     // Update machine-CFG edges
+     BB->addSuccessor(copy0MBB);
+     BB->addSuccessor(sinkMBB);
+ 
+     //  copy0MBB:
+     //   %FalseValue = ...
+     //   # fallthrough to sinkMBB
+     BB = copy0MBB;
+     // Update machine-CFG edges
+     BB->addSuccessor(sinkMBB);
+ 
+     //  sinkMBB:
+     //   %Result = phi [ %FalseValue, copy0MBB ], [ %TrueValue, thisMBB ]
+     //  ...
+     BB = sinkMBB;
+     BuildMI(BB, PPC::PHI, 4, Result).addReg(FalseValue)
+       .addMBB(copy0MBB).addReg(TrueValue).addMBB(thisMBB);
+     return Result;
+   }
+ 
+   case ISD::FNEG:
+     if (!NoExcessFPPrecision && 
+         ISD::ADD == N.getOperand(0).getOpcode() &&
+         N.getOperand(0).Val->hasOneUse() &&
+         ISD::MUL == N.getOperand(0).getOperand(0).getOpcode() &&
+         N.getOperand(0).getOperand(0).Val->hasOneUse()) {
+       ++FusedFP; // Statistic
+       Tmp1 = SelectExpr(N.getOperand(0).getOperand(0).getOperand(0));
+       Tmp2 = SelectExpr(N.getOperand(0).getOperand(0).getOperand(1));
+       Tmp3 = SelectExpr(N.getOperand(0).getOperand(1));
+       Opc = DestType == MVT::f64 ? PPC::FNMADD : PPC::FNMADDS;
+       BuildMI(BB, Opc, 3, Result).addReg(Tmp1).addReg(Tmp2).addReg(Tmp3);
+     } else if (!NoExcessFPPrecision && 
+         ISD::SUB == N.getOperand(0).getOpcode() &&
+         N.getOperand(0).Val->hasOneUse() &&
+         ISD::MUL == N.getOperand(0).getOperand(0).getOpcode() &&
+         N.getOperand(0).getOperand(0).Val->hasOneUse()) {
+       ++FusedFP; // Statistic
+       Tmp1 = SelectExpr(N.getOperand(0).getOperand(0).getOperand(0));
+       Tmp2 = SelectExpr(N.getOperand(0).getOperand(0).getOperand(1));
+       Tmp3 = SelectExpr(N.getOperand(0).getOperand(1));
+       Opc = DestType == MVT::f64 ? PPC::FNMSUB : PPC::FNMSUBS;
+       BuildMI(BB, Opc, 3, Result).addReg(Tmp1).addReg(Tmp2).addReg(Tmp3);
+     } else if (ISD::FABS == N.getOperand(0).getOpcode()) {
+       Tmp1 = SelectExpr(N.getOperand(0).getOperand(0));
+       BuildMI(BB, PPC::FNABS, 1, Result).addReg(Tmp1);
+     } else {
+       Tmp1 = SelectExpr(N.getOperand(0));
+       BuildMI(BB, PPC::FNEG, 1, Result).addReg(Tmp1);
+     }
+     return Result;
+     
+   case ISD::FABS:
+     Tmp1 = SelectExpr(N.getOperand(0));
+     BuildMI(BB, PPC::FABS, 1, Result).addReg(Tmp1);
+     return Result;
+ 
+   case ISD::FP_ROUND:
+     assert (DestType == MVT::f32 && 
+             N.getOperand(0).getValueType() == MVT::f64 && 
+             "only f64 to f32 conversion supported here");
+     Tmp1 = SelectExpr(N.getOperand(0));
+     BuildMI(BB, PPC::FRSP, 1, Result).addReg(Tmp1);
+     return Result;
+ 
+   case ISD::FP_EXTEND:
+     assert (DestType == MVT::f64 && 
+             N.getOperand(0).getValueType() == MVT::f32 && 
+             "only f32 to f64 conversion supported here");
+     Tmp1 = SelectExpr(N.getOperand(0));
+     BuildMI(BB, PPC::FMR, 1, Result).addReg(Tmp1);
+     return Result;
+ 
+   case ISD::CopyFromReg:
+     if (Result == 1)
+       Result = ExprMap[N.getValue(0)] = MakeReg(N.getValue(0).getValueType());
+     Tmp1 = dyn_cast<RegSDNode>(Node)->getReg();
+     BuildMI(BB, PPC::FMR, 1, Result).addReg(Tmp1);
+     return Result;
+     
+   case ISD::ConstantFP: {
+     ConstantFPSDNode *CN = cast<ConstantFPSDNode>(N);
+     Result = getConstDouble(CN->getValue(), Result);
+     return Result;
+   }
+     
+   case ISD::ADD:
+     if (!NoExcessFPPrecision && N.getOperand(0).getOpcode() == ISD::MUL &&
+         N.getOperand(0).Val->hasOneUse()) {
+       ++FusedFP; // Statistic
+       Tmp1 = SelectExpr(N.getOperand(0).getOperand(0));
+       Tmp2 = SelectExpr(N.getOperand(0).getOperand(1));
+       Tmp3 = SelectExpr(N.getOperand(1));
+       Opc = DestType == MVT::f64 ? PPC::FMADD : PPC::FMADDS;
+       BuildMI(BB, Opc, 3, Result).addReg(Tmp1).addReg(Tmp2).addReg(Tmp3);
+       return Result;
+     }
+     Opc = DestType == MVT::f64 ? PPC::FADD : PPC::FADDS;
+     Tmp1 = SelectExpr(N.getOperand(0));
+     Tmp2 = SelectExpr(N.getOperand(1));
+     BuildMI(BB, Opc, 2, Result).addReg(Tmp1).addReg(Tmp2);
+     return Result;
+ 
+   case ISD::SUB:
+     if (!NoExcessFPPrecision && N.getOperand(0).getOpcode() == ISD::MUL &&
+         N.getOperand(0).Val->hasOneUse()) {
+       ++FusedFP; // Statistic
+       Tmp1 = SelectExpr(N.getOperand(0).getOperand(0));
+       Tmp2 = SelectExpr(N.getOperand(0).getOperand(1));
+       Tmp3 = SelectExpr(N.getOperand(1));
+       Opc = DestType == MVT::f64 ? PPC::FMSUB : PPC::FMSUBS;
+       BuildMI(BB, Opc, 3, Result).addReg(Tmp1).addReg(Tmp2).addReg(Tmp3);
+       return Result;
+     }
+     Opc = DestType == MVT::f64 ? PPC::FSUB : PPC::FSUBS;
+     Tmp1 = SelectExpr(N.getOperand(0));
+     Tmp2 = SelectExpr(N.getOperand(1));
+     BuildMI(BB, Opc, 2, Result).addReg(Tmp1).addReg(Tmp2);
+     return Result;
+ 
+   case ISD::MUL:
+   case ISD::SDIV:
+     switch( opcode ) {
+     case ISD::MUL:  Opc = DestType == MVT::f64 ? PPC::FMUL : PPC::FMULS; break;
+     case ISD::SDIV: Opc = DestType == MVT::f64 ? PPC::FDIV : PPC::FDIVS; break;
+     };
+     Tmp1 = SelectExpr(N.getOperand(0));
+     Tmp2 = SelectExpr(N.getOperand(1));
+     BuildMI(BB, Opc, 2, Result).addReg(Tmp1).addReg(Tmp2);
+     return Result;
+ 
+   case ISD::UINT_TO_FP:
+   case ISD::SINT_TO_FP: {
+     bool IsUnsigned = (ISD::UINT_TO_FP == opcode);
+     Tmp1 = SelectExpr(N.getOperand(0));  // Get the operand register
+     Tmp2 = MakeReg(MVT::f64); // temp reg to load the integer value into
+     Tmp3 = MakeReg(MVT::i64); // temp reg to hold the conversion constant
+     unsigned ConstF = MakeReg(MVT::f64); // temp reg to hold the fp constant
+     
+     int FrameIdx = BB->getParent()->getFrameInfo()->CreateStackObject(8, 8);
+     MachineConstantPool *CP = BB->getParent()->getConstantPool();
+     
+     // FIXME: pull this FP constant generation stuff out into something like
+     // the simple ISel's getReg.
+     if (IsUnsigned) {
+       addFrameReference(BuildMI(BB, PPC::STD, 3).addReg(Tmp1), FrameIdx);
+       addFrameReference(BuildMI(BB, PPC::LFD, 2, Tmp2), FrameIdx);
+       BuildMI(BB, PPC::FCFID, 1, Result).addReg(Tmp2);
+     } else {
+       ConstantFP *CFP = ConstantFP::get(Type::DoubleTy, 0x1.000008p52);
+       unsigned CPI = CP->getConstantPoolIndex(CFP);
+       // Load constant fp value
+       unsigned Tmp4 = MakeReg(MVT::i32);
+       unsigned TmpL = MakeReg(MVT::i32);
+       BuildMI(BB, PPC::LOADHiAddr, 2, Tmp4).addReg(getGlobalBaseReg())
+         .addConstantPoolIndex(CPI);
+       BuildMI(BB, PPC::LFD, 2, ConstF).addConstantPoolIndex(CPI).addReg(Tmp4);
+       // Store the hi & low halves of the fp value, currently in int regs
+       BuildMI(BB, PPC::LIS, 1, Tmp3).addSImm(0x4330);
+       addFrameReference(BuildMI(BB, PPC::STW, 3).addReg(Tmp3), FrameIdx);
+       BuildMI(BB, PPC::XORIS, 2, TmpL).addReg(Tmp1).addImm(0x8000);
+       addFrameReference(BuildMI(BB, PPC::STW, 3).addReg(TmpL), FrameIdx, 4);
+       addFrameReference(BuildMI(BB, PPC::LFD, 2, Tmp2), FrameIdx);
+       // Generate the return value with a subtract
+       BuildMI(BB, PPC::FSUB, 2, Result).addReg(Tmp2).addReg(ConstF);
+     }
+     return Result;
+   }
+   }
+   assert(0 && "Should never get here");
+   return 0;
+ }
+ 
+ unsigned ISel::SelectExpr(SDOperand N) {
+   unsigned Result;
+   unsigned Tmp1, Tmp2, Tmp3;
+   unsigned Opc = 0;
+   unsigned opcode = N.getOpcode();
+ 
+   SDNode *Node = N.Val;
+   MVT::ValueType DestType = N.getValueType();
+ 
+   unsigned &Reg = ExprMap[N];
+   if (Reg) return Reg;
+ 
+   switch (N.getOpcode()) {
+   default:
+     Reg = Result = (N.getValueType() != MVT::Other) ?
+                             MakeReg(N.getValueType()) : 1;
+     break;
+   case ISD::CALL:
+     // If this is a call instruction, make sure to prepare ALL of the result
+     // values as well as the chain.
+     if (Node->getNumValues() == 1)
+       Reg = Result = 1;  // Void call, just a chain.
+     else {
+       Result = MakeReg(Node->getValueType(0));
+       ExprMap[N.getValue(0)] = Result;
+       for (unsigned i = 1, e = N.Val->getNumValues()-1; i != e; ++i)
+         ExprMap[N.getValue(i)] = MakeReg(Node->getValueType(i));
+       ExprMap[SDOperand(Node, Node->getNumValues()-1)] = 1;
+     }
+     break;
+   }
+ 
+   if (ISD::CopyFromReg == opcode)
+     DestType = N.getValue(0).getValueType();
+     
+   if (DestType == MVT::f64 || DestType == MVT::f32)
+     if (ISD::LOAD != opcode && ISD::EXTLOAD != opcode && ISD::UNDEF != opcode)
+       return SelectExprFP(N, Result);
+ 
+   switch (opcode) {
+   default:
+     Node->dump();
+     assert(0 && "Node not handled!\n");
+   case ISD::UNDEF:
+     BuildMI(BB, PPC::IMPLICIT_DEF, 0, Result);
+     return Result;
+   case ISD::DYNAMIC_STACKALLOC:
+     // Generate both result values.  FIXME: Need a better commment here?
+     if (Result != 1)
+       ExprMap[N.getValue(1)] = 1;
+     else
+       Result = ExprMap[N.getValue(0)] = MakeReg(N.getValue(0).getValueType());
+ 
+     // FIXME: We are currently ignoring the requested alignment for handling
+     // greater than the stack alignment.  This will need to be revisited at some
+     // point.  Align = N.getOperand(2);
+     if (!isa<ConstantSDNode>(N.getOperand(2)) ||
+         cast<ConstantSDNode>(N.getOperand(2))->getValue() != 0) {
+       std::cerr << "Cannot allocate stack object with greater alignment than"
+                 << " the stack alignment yet!";
+       abort();
+     }
+     Select(N.getOperand(0));
+     Tmp1 = SelectExpr(N.getOperand(1));
+     // Subtract size from stack pointer, thereby allocating some space.
+     BuildMI(BB, PPC::SUBF, 2, PPC::R1).addReg(Tmp1).addReg(PPC::R1);
+     // Put a pointer to the space into the result register by copying the SP
+     BuildMI(BB, PPC::OR, 2, Result).addReg(PPC::R1).addReg(PPC::R1);
+     return Result;
+ 
+   case ISD::ConstantPool:
+     Tmp1 = cast<ConstantPoolSDNode>(N)->getIndex();
+     Tmp2 = MakeReg(MVT::i64);
+     BuildMI(BB, PPC::LOADHiAddr, 2, Tmp2).addReg(getGlobalBaseReg())
+       .addConstantPoolIndex(Tmp1);
+     BuildMI(BB, PPC::LA, 2, Result).addReg(Tmp2).addConstantPoolIndex(Tmp1);
+     return Result;
+ 
+   case ISD::FrameIndex:
+     Tmp1 = cast<FrameIndexSDNode>(N)->getIndex();
+     addFrameReference(BuildMI(BB, PPC::ADDI, 2, Result), (int)Tmp1, 0, false);
+     return Result;
+   
+   case ISD::GlobalAddress: {
+     GlobalValue *GV = cast<GlobalAddressSDNode>(N)->getGlobal();
+     Tmp1 = MakeReg(MVT::i64);
+     BuildMI(BB, PPC::LOADHiAddr, 2, Tmp1).addReg(getGlobalBaseReg())
+       .addGlobalAddress(GV);
+     if (GV->hasWeakLinkage() || GV->isExternal()) {
+       BuildMI(BB, PPC::LWZ, 2, Result).addGlobalAddress(GV).addReg(Tmp1);
+     } else {
+       BuildMI(BB, PPC::LA, 2, Result).addReg(Tmp1).addGlobalAddress(GV);
+     }
+     return Result;
+   }
+ 
+   case ISD::LOAD:
+   case ISD::EXTLOAD:
+   case ISD::ZEXTLOAD:
+   case ISD::SEXTLOAD: {
+     MVT::ValueType TypeBeingLoaded = (ISD::LOAD == opcode) ?
+       Node->getValueType(0) : cast<MVTSDNode>(Node)->getExtraValueType();
+     bool sext = (ISD::SEXTLOAD == opcode);
+     bool byte = (MVT::i8 == TypeBeingLoaded);
+     
+     // Make sure we generate both values.
+     if (Result != 1)
+       ExprMap[N.getValue(1)] = 1;   // Generate the token
+     else
+       Result = ExprMap[N.getValue(0)] = MakeReg(N.getValue(0).getValueType());
+ 
+     SDOperand Chain   = N.getOperand(0);
+     SDOperand Address = N.getOperand(1);
+     Select(Chain);
+ 
+     switch (TypeBeingLoaded) {
+     default: Node->dump(); assert(0 && "Cannot load this type!");
+     case MVT::i1:  Opc = PPC::LBZ; break;
+     case MVT::i8:  Opc = PPC::LBZ; break;
+     case MVT::i16: Opc = sext ? PPC::LHA : PPC::LHZ; break;
+     case MVT::i32: Opc = sext ? PPC::LWA : PPC::LWZ; break;
+     case MVT::i64: Opc = PPC::LD;  break;
+     case MVT::f32: Opc = PPC::LFS; break;
+     case MVT::f64: Opc = PPC::LFD; break;
+     }
+     
+     if (ConstantPoolSDNode *CP = dyn_cast<ConstantPoolSDNode>(Address)) {
+       Tmp1 = MakeReg(MVT::i64);
+       int CPI = CP->getIndex();
+       BuildMI(BB, PPC::LOADHiAddr, 2, Tmp1).addReg(getGlobalBaseReg())
+         .addConstantPoolIndex(CPI);
+       BuildMI(BB, Opc, 2, Result).addConstantPoolIndex(CPI).addReg(Tmp1);
+     }
+     else if(Address.getOpcode() == ISD::FrameIndex) {
+       Tmp1 = cast<FrameIndexSDNode>(Address)->getIndex();
+       addFrameReference(BuildMI(BB, Opc, 2, Result), (int)Tmp1);
+     } else {
+       int offset;
+       bool idx = SelectAddr(Address, Tmp1, offset);
+       if (idx) {
+         Opc = IndexedOpForOp(Opc);
+         BuildMI(BB, Opc, 2, Result).addReg(Tmp1).addReg(offset);
+       } else {
+         BuildMI(BB, Opc, 2, Result).addSImm(offset).addReg(Tmp1);
+       }
+     }
+     return Result;
+   }
+     
+   case ISD::CALL: {
+     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
+     };
+ 
+     // Lower the chain for this call.
+     Select(N.getOperand(0));
+     ExprMap[N.getValue(Node->getNumValues()-1)] = 1;
+ 
+     MachineInstr *CallMI;
+     // Emit the correct call instruction based on the type of symbol called.
+     if (GlobalAddressSDNode *GASD = 
+         dyn_cast<GlobalAddressSDNode>(N.getOperand(1))) {
+       CallMI = BuildMI(PPC::CALLpcrel, 1).addGlobalAddress(GASD->getGlobal(), 
+                                                            true);
+     } else if (ExternalSymbolSDNode *ESSDN = 
+                dyn_cast<ExternalSymbolSDNode>(N.getOperand(1))) {
+       CallMI = BuildMI(PPC::CALLpcrel, 1).addExternalSymbol(ESSDN->getSymbol(), 
+                                                             true);
+     } else {
+       Tmp1 = SelectExpr(N.getOperand(1));
+       BuildMI(BB, PPC::OR, 2, PPC::R12).addReg(Tmp1).addReg(Tmp1);
+       BuildMI(BB, PPC::MTCTR, 1).addReg(PPC::R12);
+       CallMI = BuildMI(PPC::CALLindirect, 3).addImm(20).addImm(0)
+         .addReg(PPC::R12);
+     }
+        
+     // Load the register args to virtual regs
+     std::vector<unsigned> ArgVR;
+     for(int i = 2, e = Node->getNumOperands(); i < e; ++i)
+       ArgVR.push_back(SelectExpr(N.getOperand(i)));
+ 
+     // Copy the virtual registers into the appropriate argument register
+     for(int i = 0, e = ArgVR.size(); i < e; ++i) {
+       switch(N.getOperand(i+2).getValueType()) {
+       default: Node->dump(); assert(0 && "Unknown value type for call");
+       case MVT::i1:
+       case MVT::i8:
+       case MVT::i16:
+       case MVT::i32:
+       case MVT::i64:
+         assert(GPR_idx < 8 && "Too many int args");
+         if (N.getOperand(i+2).getOpcode() != ISD::UNDEF) {
+           BuildMI(BB, PPC::OR,2,GPR[GPR_idx]).addReg(ArgVR[i]).addReg(ArgVR[i]);
+           CallMI->addRegOperand(GPR[GPR_idx], MachineOperand::Use);
+         }
+         ++GPR_idx;
+         break;
+       case MVT::f64:
+       case MVT::f32:
+         assert(FPR_idx < 13 && "Too many fp args");
+         BuildMI(BB, PPC::FMR, 1, FPR[FPR_idx]).addReg(ArgVR[i]);
+         CallMI->addRegOperand(FPR[FPR_idx], MachineOperand::Use);
+         ++FPR_idx;
+         break;
+       }
+     }
+     
+     // Put the call instruction in the correct place in the MachineBasicBlock
+     BB->push_back(CallMI);
+ 
+     switch (Node->getValueType(0)) {
+     default: assert(0 && "Unknown value type for call result!");
+     case MVT::Other: return 1;
+     case MVT::i1:
+     case MVT::i8:
+     case MVT::i16:
+     case MVT::i32:
+     case MVT::i64:
+       BuildMI(BB, PPC::OR, 2, Result).addReg(PPC::R3).addReg(PPC::R3);
+       break;
+     case MVT::f32:
+     case MVT::f64:
+       BuildMI(BB, PPC::FMR, 1, Result).addReg(PPC::F1);
+       break;
+     }
+     return Result+N.ResNo;
+   }
+ 
+   case ISD::SIGN_EXTEND:
+   case ISD::SIGN_EXTEND_INREG:
+     Tmp1 = SelectExpr(N.getOperand(0));
+     switch(cast<MVTSDNode>(Node)->getExtraValueType()) {
+     default: Node->dump(); assert(0 && "Unhandled SIGN_EXTEND type"); break;
+     case MVT::i32:
+       BuildMI(BB, PPC::EXTSW, 1, Result).addReg(Tmp1); 
+       break;
+     case MVT::i16:
+       BuildMI(BB, PPC::EXTSH, 1, Result).addReg(Tmp1); 
+       break;
+     case MVT::i8:
+       BuildMI(BB, PPC::EXTSB, 1, Result).addReg(Tmp1); 
+       break;
+     case MVT::i1:
+       BuildMI(BB, PPC::SUBFIC, 2, Result).addReg(Tmp1).addSImm(0);
+       break;
+     }
+     return Result;
+     
+   case ISD::ZERO_EXTEND_INREG:
+     Tmp1 = SelectExpr(N.getOperand(0));
+     switch(cast<MVTSDNode>(Node)->getExtraValueType()) {
+     default: Node->dump(); assert(0 && "Unhandled ZERO_EXTEND type"); break;
+     case MVT::i16:  Tmp2 = 16; break;
+     case MVT::i8:   Tmp2 = 24; break;
+     case MVT::i1:   Tmp2 = 31; break;
+     }
+     BuildMI(BB, PPC::RLWINM, 4, Result).addReg(Tmp1).addImm(0).addImm(Tmp2)
+       .addImm(31);
+     return Result;
+     
+   case ISD::CopyFromReg:
+     if (Result == 1)
+       Result = ExprMap[N.getValue(0)] = MakeReg(N.getValue(0).getValueType());
+     Tmp1 = dyn_cast<RegSDNode>(Node)->getReg();
+     BuildMI(BB, PPC::OR, 2, Result).addReg(Tmp1).addReg(Tmp1);
+     return Result;
+ 
+   case ISD::SHL:
+     Tmp1 = SelectExpr(N.getOperand(0));
+     if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N.getOperand(1))) {
+       Tmp2 = CN->getValue() & 0x1F;
+       BuildMI(BB, PPC::RLWINM, 4, Result).addReg(Tmp1).addImm(Tmp2).addImm(0)
+         .addImm(31-Tmp2);
+     } else {
+       Tmp2 = SelectExpr(N.getOperand(1));
+       BuildMI(BB, PPC::SLW, 2, Result).addReg(Tmp1).addReg(Tmp2);
+     }
+     return Result;
+     
+   case ISD::SRL:
+     Tmp1 = SelectExpr(N.getOperand(0));
+     if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N.getOperand(1))) {
+       Tmp2 = CN->getValue() & 0x1F;
+       BuildMI(BB, PPC::RLWINM, 4, Result).addReg(Tmp1).addImm(32-Tmp2)
+         .addImm(Tmp2).addImm(31);
+     } else {
+       Tmp2 = SelectExpr(N.getOperand(1));
+       BuildMI(BB, PPC::SRW, 2, Result).addReg(Tmp1).addReg(Tmp2);
+     }
+     return Result;
+     
+   case ISD::SRA:
+     Tmp1 = SelectExpr(N.getOperand(0));
+     if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N.getOperand(1))) {
+       Tmp2 = CN->getValue() & 0x1F;
+       BuildMI(BB, PPC::SRAWI, 2, Result).addReg(Tmp1).addImm(Tmp2);
+     } else {
+       Tmp2 = SelectExpr(N.getOperand(1));
+       BuildMI(BB, PPC::SRAW, 2, Result).addReg(Tmp1).addReg(Tmp2);
+     }
+     return Result;
+   
+   case ISD::ADD:
+     Tmp1 = SelectExpr(N.getOperand(0));
+     switch(getImmediateForOpcode(N.getOperand(1), opcode, Tmp2)) {
+       default: assert(0 && "unhandled result code");
+       case 0: // No immediate
+         Tmp2 = SelectExpr(N.getOperand(1));
+         BuildMI(BB, PPC::ADD, 2, Result).addReg(Tmp1).addReg(Tmp2);
+         break;
+       case 1: // Low immediate
+         BuildMI(BB, PPC::ADDI, 2, Result).addReg(Tmp1).addSImm(Tmp2);
+         break;
+       case 2: // Shifted immediate
+         BuildMI(BB, PPC::ADDIS, 2, Result).addReg(Tmp1).addSImm(Tmp2);
+         break;
+     }
+     return Result;
+ 
+   case ISD::AND:
+   case ISD::OR:
+     Tmp1 = SelectExpr(N.getOperand(0));
+     switch(getImmediateForOpcode(N.getOperand(1), opcode, Tmp2)) {
+       default: assert(0 && "unhandled result code");
+       case 0: // No immediate
+         Tmp2 = SelectExpr(N.getOperand(1));
+         switch (opcode) {
+         case ISD::AND: Opc = PPC::AND; break;
+         case ISD::OR:  Opc = PPC::OR;  break;
+         }
+         BuildMI(BB, Opc, 2, Result).addReg(Tmp1).addReg(Tmp2);
+         break;
+       case 1: // Low immediate
+         switch (opcode) {
+         case ISD::AND: Opc = PPC::ANDIo; break;
+         case ISD::OR:  Opc = PPC::ORI;   break;
+         }
+         BuildMI(BB, Opc, 2, Result).addReg(Tmp1).addImm(Tmp2);
+         break;
+       case 2: // Shifted immediate
+         switch (opcode) {
+         case ISD::AND: Opc = PPC::ANDISo;  break;
+         case ISD::OR:  Opc = PPC::ORIS;    break;
+         }
+         BuildMI(BB, Opc, 2, Result).addReg(Tmp1).addImm(Tmp2);
+         break;
+     }
+     return Result;
+ 
+   case ISD::XOR: {
+     // Check for EQV: xor, (xor a, -1), b
+     if (N.getOperand(0).getOpcode() == ISD::XOR &&
+         N.getOperand(0).getOperand(1).getOpcode() == ISD::Constant &&
+         cast<ConstantSDNode>(N.getOperand(0).getOperand(1))->isAllOnesValue()) {
+       ++NotLogic;
+       Tmp1 = SelectExpr(N.getOperand(0).getOperand(0));
+       Tmp2 = SelectExpr(N.getOperand(1));
+       BuildMI(BB, PPC::EQV, 2, Result).addReg(Tmp1).addReg(Tmp2);
+       return Result;
+     }
+     // Check for NOT, NOR, and NAND: xor (copy, or, and), -1
+     if (N.getOperand(1).getOpcode() == ISD::Constant &&
+         cast<ConstantSDNode>(N.getOperand(1))->isAllOnesValue()) {
+       ++NotLogic;
+       switch(N.getOperand(0).getOpcode()) {
+       case ISD::OR:
+         Tmp1 = SelectExpr(N.getOperand(0).getOperand(0));
+         Tmp2 = SelectExpr(N.getOperand(0).getOperand(1));
+         BuildMI(BB, PPC::NOR, 2, Result).addReg(Tmp1).addReg(Tmp2);
+         break;
+       case ISD::AND:
+         Tmp1 = SelectExpr(N.getOperand(0).getOperand(0));
+         Tmp2 = SelectExpr(N.getOperand(0).getOperand(1));
+         BuildMI(BB, PPC::NAND, 2, Result).addReg(Tmp1).addReg(Tmp2);
+         break;
+       default:
+         Tmp1 = SelectExpr(N.getOperand(0));
+         BuildMI(BB, PPC::NOR, 2, Result).addReg(Tmp1).addReg(Tmp1);
+         break;
+       }
+       return Result;
+     }
+     Tmp1 = SelectExpr(N.getOperand(0));
+     switch(getImmediateForOpcode(N.getOperand(1), opcode, Tmp2)) {
+       default: assert(0 && "unhandled result code");
+       case 0: // No immediate
+         Tmp2 = SelectExpr(N.getOperand(1));
+         BuildMI(BB, PPC::XOR, 2, Result).addReg(Tmp1).addReg(Tmp2);
+         break;
+       case 1: // Low immediate
+         BuildMI(BB, PPC::XORI, 2, Result).addReg(Tmp1).addImm(Tmp2);
+         break;
+       case 2: // Shifted immediate
+         BuildMI(BB, PPC::XORIS, 2, Result).addReg(Tmp1).addImm(Tmp2);
+         break;
+     }
+     return Result;
+   }
+ 
+   case ISD::SUB:
+     Tmp2 = SelectExpr(N.getOperand(1));
+     if (1 == getImmediateForOpcode(N.getOperand(0), opcode, Tmp1))
+       BuildMI(BB, PPC::SUBFIC, 2, Result).addReg(Tmp2).addSImm(Tmp1);
+     else {
+       Tmp1 = SelectExpr(N.getOperand(0));
+       BuildMI(BB, PPC::SUBF, 2, Result).addReg(Tmp2).addReg(Tmp1);
+     }
+     return Result;
+     
+   case ISD::MUL:
+     Tmp1 = SelectExpr(N.getOperand(0));
+     if (1 == getImmediateForOpcode(N.getOperand(1), opcode, Tmp2))
+       BuildMI(BB, PPC::MULLI, 2, Result).addReg(Tmp1).addSImm(Tmp2);
+     else {
+       Tmp2 = SelectExpr(N.getOperand(1));
+       BuildMI(BB, PPC::MULLD, 2, Result).addReg(Tmp1).addReg(Tmp2);
+     }
+     return Result;
+ 
+   case ISD::SDIV:
+   case ISD::UDIV:
+     if (3 == getImmediateForOpcode(N.getOperand(1), opcode, Tmp3)) {
+       Tmp1 = MakeReg(MVT::i64);
+       Tmp2 = SelectExpr(N.getOperand(0));
+       BuildMI(BB, PPC::SRAWI, 2, Tmp1).addReg(Tmp2).addImm(Tmp3);
+       BuildMI(BB, PPC::ADDZE, 1, Result).addReg(Tmp1);
+       return Result;
+     }
+     Tmp1 = SelectExpr(N.getOperand(0));
+     Tmp2 = SelectExpr(N.getOperand(1));
+     Opc = (ISD::UDIV == opcode) ? PPC::DIVWU : PPC::DIVW;
+     BuildMI(BB, Opc, 2, Result).addReg(Tmp1).addReg(Tmp2);
+     return Result;
+ 
+   case ISD::UREM:
+   case ISD::SREM: {
+     Tmp1 = SelectExpr(N.getOperand(0));
+     Tmp2 = SelectExpr(N.getOperand(1));
+     Tmp3 = MakeReg(MVT::i64);
+     unsigned Tmp4 = MakeReg(MVT::i64);
+     Opc = (ISD::UREM == opcode) ? PPC::DIVDU : PPC::DIVD;
+     BuildMI(BB, Opc, 2, Tmp3).addReg(Tmp1).addReg(Tmp2);
+     BuildMI(BB, PPC::MULLD, 2, Tmp4).addReg(Tmp3).addReg(Tmp2);
+     BuildMI(BB, PPC::SUBF, 2, Result).addReg(Tmp4).addReg(Tmp1);
+     return Result;
+   }
+     
+   case ISD::FP_TO_UINT:
+   case ISD::FP_TO_SINT: {
+     bool U = (ISD::FP_TO_UINT == opcode);
+     Tmp1 = SelectExpr(N.getOperand(0));
+     if (!U) {
+       Tmp2 = MakeReg(MVT::f64);
+       BuildMI(BB, PPC::FCTIWZ, 1, Tmp2).addReg(Tmp1);
+       int FrameIdx = BB->getParent()->getFrameInfo()->CreateStackObject(8, 8);
+       addFrameReference(BuildMI(BB, PPC::STFD, 3).addReg(Tmp2), FrameIdx);
+       addFrameReference(BuildMI(BB, PPC::LWZ, 2, Result), FrameIdx, 4);
+       return Result;
+     } else {
+       unsigned Zero = getConstDouble(0.0);
+       unsigned MaxInt = getConstDouble((1LL << 32) - 1);
+       unsigned Border = getConstDouble(1LL << 31);
+       unsigned UseZero = MakeReg(MVT::f64);
+       unsigned UseMaxInt = MakeReg(MVT::f64);
+       unsigned UseChoice = MakeReg(MVT::f64);
+       unsigned TmpReg = MakeReg(MVT::f64);
+       unsigned TmpReg2 = MakeReg(MVT::f64);
+       unsigned ConvReg = MakeReg(MVT::f64);
+       unsigned IntTmp = MakeReg(MVT::i32);
+       unsigned XorReg = MakeReg(MVT::i32);
+       MachineFunction *F = BB->getParent();
+       int FrameIdx = F->getFrameInfo()->CreateStackObject(8, 8);
+       // Update machine-CFG edges
+       MachineBasicBlock *XorMBB = new MachineBasicBlock(BB->getBasicBlock());
+       MachineBasicBlock *PhiMBB = new MachineBasicBlock(BB->getBasicBlock());
+       MachineBasicBlock *OldMBB = BB;
+       ilist<MachineBasicBlock>::iterator It = BB; ++It;
+       F->getBasicBlockList().insert(It, XorMBB);
+       F->getBasicBlockList().insert(It, PhiMBB);
+       BB->addSuccessor(XorMBB);
+       BB->addSuccessor(PhiMBB);
+       // Convert from floating point to unsigned 32-bit value
+       // Use 0 if incoming value is < 0.0
+       BuildMI(BB, PPC::FSEL, 3, UseZero).addReg(Tmp1).addReg(Tmp1).addReg(Zero);
+       // Use 2**32 - 1 if incoming value is >= 2**32
+       BuildMI(BB, PPC::FSUB, 2, UseMaxInt).addReg(MaxInt).addReg(Tmp1);
+       BuildMI(BB, PPC::FSEL, 3, UseChoice).addReg(UseMaxInt).addReg(UseZero)
+         .addReg(MaxInt);
+       // Subtract 2**31
+       BuildMI(BB, PPC::FSUB, 2, TmpReg).addReg(UseChoice).addReg(Border);
+       // Use difference if >= 2**31
+       BuildMI(BB, PPC::FCMPU, 2, PPC::CR0).addReg(UseChoice).addReg(Border);
+       BuildMI(BB, PPC::FSEL, 3, TmpReg2).addReg(TmpReg).addReg(TmpReg)
+         .addReg(UseChoice);
+       // Convert to integer
+       BuildMI(BB, PPC::FCTIWZ, 1, ConvReg).addReg(TmpReg2);
+       addFrameReference(BuildMI(BB, PPC::STFD, 3).addReg(ConvReg), FrameIdx);
+       addFrameReference(BuildMI(BB, PPC::LWZ, 2, IntTmp), FrameIdx, 4);
+       BuildMI(BB, PPC::BLT, 2).addReg(PPC::CR0).addMBB(PhiMBB);
+       BuildMI(BB, PPC::B, 1).addMBB(XorMBB);
+ 
+       // XorMBB:
+       //   add 2**31 if input was >= 2**31
+       BB = XorMBB;
+       BuildMI(BB, PPC::XORIS, 2, XorReg).addReg(IntTmp).addImm(0x8000);
+       XorMBB->addSuccessor(PhiMBB);
+ 
+       // PhiMBB:
+       //   DestReg = phi [ IntTmp, OldMBB ], [ XorReg, XorMBB ]
+       BB = PhiMBB;
+       BuildMI(BB, PPC::PHI, 4, Result).addReg(IntTmp).addMBB(OldMBB)
+         .addReg(XorReg).addMBB(XorMBB);
+       return Result;
+     }
+     assert(0 && "Should never get here");
+     return 0;
+   }
+  
+   case ISD::SETCC:
+     if (SetCCSDNode *SetCC = dyn_cast<SetCCSDNode>(Node)) {
+       Opc = SelectSetCR0(N);
+       
+       unsigned TrueValue = MakeReg(MVT::i32);
+       BuildMI(BB, PPC::LI, 1, TrueValue).addSImm(1);
+       unsigned FalseValue = MakeReg(MVT::i32);
+       BuildMI(BB, PPC::LI, 1, FalseValue).addSImm(0);
+ 
+       // Create an iterator with which to insert the MBB for copying the false 
+       // value and the MBB to hold the PHI instruction for this SetCC.
+       MachineBasicBlock *thisMBB = BB;
+       const BasicBlock *LLVM_BB = BB->getBasicBlock();
+       ilist<MachineBasicBlock>::iterator It = BB;
+       ++It;
+   
+       //  thisMBB:
+       //  ...
+       //   cmpTY cr0, r1, r2
+       //   %TrueValue = li 1
+       //   bCC sinkMBB
+       MachineBasicBlock *copy0MBB = new MachineBasicBlock(LLVM_BB);
+       MachineBasicBlock *sinkMBB = new MachineBasicBlock(LLVM_BB);
+       BuildMI(BB, Opc, 2).addReg(PPC::CR0).addMBB(sinkMBB);
+       MachineFunction *F = BB->getParent();
+       F->getBasicBlockList().insert(It, copy0MBB);
+       F->getBasicBlockList().insert(It, sinkMBB);
+       // Update machine-CFG edges
+       BB->addSuccessor(copy0MBB);
+       BB->addSuccessor(sinkMBB);
+ 
+       //  copy0MBB:
+       //   %FalseValue = li 0
+       //   fallthrough
+       BB = copy0MBB;
+       // Update machine-CFG edges
+       BB->addSuccessor(sinkMBB);
+ 
+       //  sinkMBB:
+       //   %Result = phi [ %FalseValue, copy0MBB ], [ %TrueValue, thisMBB ]
+       //  ...
+       BB = sinkMBB;
+       BuildMI(BB, PPC::PHI, 4, Result).addReg(FalseValue)
+         .addMBB(copy0MBB).addReg(TrueValue).addMBB(thisMBB);
+       return Result;
+     }
+     assert(0 && "Is this legal?");
+     return 0;
+     
+   case ISD::SELECT: {
+     unsigned TrueValue = SelectExpr(N.getOperand(1)); //Use if TRUE
+     unsigned FalseValue = SelectExpr(N.getOperand(2)); //Use if FALSE
+     Opc = SelectSetCR0(N.getOperand(0));
+ 
+     // Create an iterator with which to insert the MBB for copying the false 
+     // value and the MBB to hold the PHI instruction for this SetCC.
+     MachineBasicBlock *thisMBB = BB;
+     const BasicBlock *LLVM_BB = BB->getBasicBlock();
+     ilist<MachineBasicBlock>::iterator It = BB;
+     ++It;
+ 
+     //  thisMBB:
+     //  ...
+     //   TrueVal = ...
+     //   cmpTY cr0, r1, r2
+     //   bCC copy1MBB
+     //   fallthrough --> copy0MBB
+     MachineBasicBlock *copy0MBB = new MachineBasicBlock(LLVM_BB);
+     MachineBasicBlock *sinkMBB = new MachineBasicBlock(LLVM_BB);
+     BuildMI(BB, Opc, 2).addReg(PPC::CR0).addMBB(sinkMBB);
+     MachineFunction *F = BB->getParent();
+     F->getBasicBlockList().insert(It, copy0MBB);
+     F->getBasicBlockList().insert(It, sinkMBB);
+     // Update machine-CFG edges
+     BB->addSuccessor(copy0MBB);
+     BB->addSuccessor(sinkMBB);
+ 
+     //  copy0MBB:
+     //   %FalseValue = ...
+     //   # fallthrough to sinkMBB
+     BB = copy0MBB;
+     // Update machine-CFG edges
+     BB->addSuccessor(sinkMBB);
+ 
+     //  sinkMBB:
+     //   %Result = phi [ %FalseValue, copy0MBB ], [ %TrueValue, thisMBB ]
+     //  ...
+     BB = sinkMBB;
+     BuildMI(BB, PPC::PHI, 4, Result).addReg(FalseValue)
+       .addMBB(copy0MBB).addReg(TrueValue).addMBB(thisMBB);
+ 
+     // FIXME: Select i64?
+     return Result;
+   }
+ 
+   case ISD::Constant:
+     switch (N.getValueType()) {
+     default: assert(0 && "Cannot use constants of this type!");
+     case MVT::i1:
+       BuildMI(BB, PPC::LI, 1, Result)
+         .addSImm(!cast<ConstantSDNode>(N)->isNullValue());
+       break;
+     case MVT::i32:
+       {
+         int v = (int)cast<ConstantSDNode>(N)->getSignExtended();
+         if (v < 32768 && v >= -32768) {
+           BuildMI(BB, PPC::LI, 1, Result).addSImm(v);
+         } else {
+           Tmp1 = MakeReg(MVT::i32);
+           BuildMI(BB, PPC::LIS, 1, Tmp1).addSImm(v >> 16);
+           BuildMI(BB, PPC::ORI, 2, Result).addReg(Tmp1).addImm(v & 0xFFFF);
+         }
+       }
+     }
+     return Result;
+   }
+ 
+   return 0;
+ }
+ 
+ void ISel::Select(SDOperand N) {
+   unsigned Tmp1, Tmp2, Opc;
+   unsigned opcode = N.getOpcode();
+ 
+   if (!ExprMap.insert(std::make_pair(N, 1)).second)
+     return;  // Already selected.
+ 
+   SDNode *Node = N.Val;
+   
+   switch (Node->getOpcode()) {
+   default:
+     Node->dump(); std::cerr << "\n";
+     assert(0 && "Node not handled yet!");
+   case ISD::EntryToken: return;  // Noop
+   case ISD::TokenFactor:
+     for (unsigned i = 0, e = Node->getNumOperands(); i != e; ++i)
+       Select(Node->getOperand(i));
+     return;
+   case ISD::ADJCALLSTACKDOWN:
+   case ISD::ADJCALLSTACKUP:
+     Select(N.getOperand(0));
+     Tmp1 = cast<ConstantSDNode>(N.getOperand(1))->getValue();
+     Opc = N.getOpcode() == ISD::ADJCALLSTACKDOWN ? PPC::ADJCALLSTACKDOWN :
+       PPC::ADJCALLSTACKUP;
+     BuildMI(BB, Opc, 1).addImm(Tmp1);
+     return;
+   case ISD::BR: {
+     MachineBasicBlock *Dest =
+       cast<BasicBlockSDNode>(N.getOperand(1))->getBasicBlock();
+     Select(N.getOperand(0));
+     BuildMI(BB, PPC::B, 1).addMBB(Dest);
+     return;
+   }
+   case ISD::BRCOND: 
+     SelectBranchCC(N);
+     return;
+   case ISD::CopyToReg:
+     Select(N.getOperand(0));
+     Tmp1 = SelectExpr(N.getOperand(1));
+     Tmp2 = cast<RegSDNode>(N)->getReg();
+     
+     if (Tmp1 != Tmp2) {
+       if (N.getOperand(1).getValueType() == MVT::f64 || 
+           N.getOperand(1).getValueType() == MVT::f32)
+         BuildMI(BB, PPC::FMR, 1, Tmp2).addReg(Tmp1);
+       else
+         BuildMI(BB, PPC::OR, 2, Tmp2).addReg(Tmp1).addReg(Tmp1);
+     }
+     return;
+   case ISD::ImplicitDef:
+     Select(N.getOperand(0));
+     BuildMI(BB, PPC::IMPLICIT_DEF, 0, cast<RegSDNode>(N)->getReg());
+     return;
+   case ISD::RET:
+     switch (N.getNumOperands()) {
+     default:
+       assert(0 && "Unknown return instruction!");
+     case 3:
+       assert(N.getOperand(1).getValueType() == MVT::i32 &&
+              N.getOperand(2).getValueType() == MVT::i32 &&
+ 	           "Unknown two-register value!");
+       Select(N.getOperand(0));
+       Tmp1 = SelectExpr(N.getOperand(1));
+       Tmp2 = SelectExpr(N.getOperand(2));
+       BuildMI(BB, PPC::OR, 2, PPC::R3).addReg(Tmp2).addReg(Tmp2);
+       BuildMI(BB, PPC::OR, 2, PPC::R4).addReg(Tmp1).addReg(Tmp1);
+       break;
+     case 2:
+       Select(N.getOperand(0));
+       Tmp1 = SelectExpr(N.getOperand(1));
+       switch (N.getOperand(1).getValueType()) {
+         default:
+           assert(0 && "Unknown return type!");
+         case MVT::f64:
+         case MVT::f32:
+           BuildMI(BB, PPC::FMR, 1, PPC::F1).addReg(Tmp1);
+           break;
+         case MVT::i32:
+           BuildMI(BB, PPC::OR, 2, PPC::R3).addReg(Tmp1).addReg(Tmp1);
+           break;
+       }
+     case 1:
+       Select(N.getOperand(0));
+       break;
+     }
+     BuildMI(BB, PPC::BLR, 0); // Just emit a 'ret' instruction
+     return;
+   case ISD::TRUNCSTORE: 
+   case ISD::STORE: 
+     {
+       SDOperand Chain   = N.getOperand(0);
+       SDOperand Value   = N.getOperand(1);
+       SDOperand Address = N.getOperand(2);
+       Select(Chain);
+ 
+       Tmp1 = SelectExpr(Value); //value
+ 
+       if (opcode == ISD::STORE) {
+         switch(Value.getValueType()) {
+         default: assert(0 && "unknown Type in store");
+         case MVT::i64: Opc = PPC::STD; break;
+         case MVT::f64: Opc = PPC::STFD; break;
+         case MVT::f32: Opc = PPC::STFS; break;
+         }
+       } else { //ISD::TRUNCSTORE
+         switch(cast<MVTSDNode>(Node)->getExtraValueType()) {
+         default: assert(0 && "unknown Type in store");
+         case MVT::i1: //FIXME: DAG does not promote this load
+         case MVT::i8:  Opc= PPC::STB; break;
+         case MVT::i16: Opc = PPC::STH; break;
+         case MVT::i32: Opc = PPC::STW; break;
+         }
+       }
+ 
+       if(Address.getOpcode() == ISD::FrameIndex)
+       {
+         Tmp2 = cast<FrameIndexSDNode>(Address)->getIndex();
+         addFrameReference(BuildMI(BB, Opc, 3).addReg(Tmp1), (int)Tmp2);
+       }
+       else
+       {
+         int offset;
+         bool idx = SelectAddr(Address, Tmp2, offset);
+         if (idx) { 
+           Opc = IndexedOpForOp(Opc);
+           BuildMI(BB, Opc, 3).addReg(Tmp1).addReg(Tmp2).addReg(offset);
+         } else {
+           BuildMI(BB, Opc, 3).addReg(Tmp1).addImm(offset).addReg(Tmp2);
+         }
+       }
+       return;
+     }
+   case ISD::EXTLOAD:
+   case ISD::SEXTLOAD:
+   case ISD::ZEXTLOAD:
+   case ISD::LOAD:
+   case ISD::CopyFromReg:
+   case ISD::CALL:
+   case ISD::DYNAMIC_STACKALLOC:
+     ExprMap.erase(N);
+     SelectExpr(N);
+     return;
+   }
+   assert(0 && "Should not be reached!");
+ }
+ 
+ 
+ /// createPPC32PatternInstructionSelector - This pass converts an LLVM function
+ /// into a machine code representation using pattern matching and a machine
+ /// description file.
+ ///
+ FunctionPass *llvm::createPPC64ISelPattern(TargetMachine &TM) {
+   return new ISel(TM);  
+ }
+ 


Index: llvm/lib/Target/PowerPC/PowerPC.h
diff -u llvm/lib/Target/PowerPC/PowerPC.h:1.12 llvm/lib/Target/PowerPC/PowerPC.h:1.13
--- llvm/lib/Target/PowerPC/PowerPC.h:1.12	Wed Mar 23 22:41:43 2005
+++ llvm/lib/Target/PowerPC/PowerPC.h	Tue Apr  5 03:51:15 2005
@@ -25,7 +25,7 @@
 FunctionPass *createPPCBranchSelectionPass();
 FunctionPass *createPPC32ISelSimple(TargetMachine &TM);
 FunctionPass *createPPC32ISelPattern(TargetMachine &TM);
-FunctionPass *createPPC64ISelSimple(TargetMachine &TM);
+FunctionPass *createPPC64ISelPattern(TargetMachine &TM);
 FunctionPass *createDarwinAsmPrinter(std::ostream &OS, TargetMachine &TM);
 FunctionPass *createAIXAsmPrinter(std::ostream &OS, TargetMachine &TM);
 


Index: llvm/lib/Target/PowerPC/PowerPCTargetMachine.cpp
diff -u llvm/lib/Target/PowerPC/PowerPCTargetMachine.cpp:1.48 llvm/lib/Target/PowerPC/PowerPCTargetMachine.cpp:1.49
--- llvm/lib/Target/PowerPC/PowerPCTargetMachine.cpp:1.48	Thu Mar 24 00:28:42 2005
+++ llvm/lib/Target/PowerPC/PowerPCTargetMachine.cpp	Tue Apr  5 03:51:15 2005
@@ -97,7 +97,7 @@
   PM.add(createUnreachableBlockEliminationPass());
 
   if (LP64)
-    PM.add(createPPC64ISelSimple(*this));
+    PM.add(createPPC64ISelPattern(*this));
   else if (EnablePatternISel)
     PM.add(createPPC32ISelPattern(*this));
   else






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