It's not necessary to do rounding for alloca operations when the requested
alignment is equal to the stack alignment.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40004 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/IA64/IA64ISelDAGToDAG.cpp b/lib/Target/IA64/IA64ISelDAGToDAG.cpp
new file mode 100644
index 0000000..53b704e
--- /dev/null
+++ b/lib/Target/IA64/IA64ISelDAGToDAG.cpp
@@ -0,0 +1,587 @@
+//===---- IA64ISelDAGToDAG.cpp - IA64 pattern matching inst selector ------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by Duraid Madina 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 IA64,
+// converting a legalized dag to an IA64 dag.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "ia64-codegen"
+#include "IA64.h"
+#include "IA64TargetMachine.h"
+#include "IA64ISelLowering.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/SSARegMap.h"
+#include "llvm/CodeGen/SelectionDAG.h"
+#include "llvm/CodeGen/SelectionDAGISel.h"
+#include "llvm/Target/TargetOptions.h"
+#include "llvm/Constants.h"
+#include "llvm/GlobalValue.h"
+#include "llvm/Intrinsics.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/MathExtras.h"
+#include <queue>
+#include <set>
+using namespace llvm;
+
+namespace {
+  //===--------------------------------------------------------------------===//
+  /// IA64DAGToDAGISel - IA64 specific code to select IA64 machine
+  /// instructions for SelectionDAG operations.
+  ///
+  class IA64DAGToDAGISel : public SelectionDAGISel {
+    IA64TargetLowering IA64Lowering;
+    unsigned GlobalBaseReg;
+  public:
+    IA64DAGToDAGISel(IA64TargetMachine &TM)
+      : SelectionDAGISel(IA64Lowering), IA64Lowering(*TM.getTargetLowering()) {}
+    
+    virtual bool runOnFunction(Function &Fn) {
+      // Make sure we re-emit a set of the global base reg if necessary
+      GlobalBaseReg = 0;
+      return SelectionDAGISel::runOnFunction(Fn);
+    }
+ 
+    /// getI64Imm - Return a target constant with the specified value, of type
+    /// i64.
+    inline SDOperand getI64Imm(uint64_t Imm) {
+      return CurDAG->getTargetConstant(Imm, MVT::i64);
+    }
+
+    /// getGlobalBaseReg - insert code into the entry mbb to materialize the PIC
+    /// base register.  Return the virtual register that holds this value.
+    // SDOperand getGlobalBaseReg(); TODO: hmm
+    
+    // Select - Convert the specified operand from a target-independent to a
+    // target-specific node if it hasn't already been changed.
+    SDNode *Select(SDOperand N);
+    
+    SDNode *SelectIntImmediateExpr(SDOperand LHS, SDOperand RHS,
+                                   unsigned OCHi, unsigned OCLo,
+                                   bool IsArithmetic = false,
+                                   bool Negate = false);
+    SDNode *SelectBitfieldInsert(SDNode *N);
+
+    /// SelectCC - Select a comparison of the specified values with the
+    /// specified condition code, returning the CR# of the expression.
+    SDOperand SelectCC(SDOperand LHS, SDOperand RHS, ISD::CondCode CC);
+
+    /// SelectAddr - Given the specified address, return the two operands for a
+    /// load/store instruction, and return true if it should be an indexed [r+r]
+    /// operation.
+    bool SelectAddr(SDOperand Addr, SDOperand &Op1, SDOperand &Op2);
+
+    /// InstructionSelectBasicBlock - This callback is invoked by
+    /// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
+    virtual void InstructionSelectBasicBlock(SelectionDAG &DAG);
+    
+    virtual const char *getPassName() const {
+      return "IA64 (Itanium) DAG->DAG Instruction Selector";
+    } 
+
+// Include the pieces autogenerated from the target description.
+#include "IA64GenDAGISel.inc"
+    
+private:
+    SDNode *SelectDIV(SDOperand Op);
+  };
+}
+
+/// InstructionSelectBasicBlock - This callback is invoked by
+/// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
+void IA64DAGToDAGISel::InstructionSelectBasicBlock(SelectionDAG &DAG) {
+  DEBUG(BB->dump());
+
+  // Select target instructions for the DAG.
+  DAG.setRoot(SelectRoot(DAG.getRoot()));
+  DAG.RemoveDeadNodes();
+  
+  // Emit machine code to BB. 
+  ScheduleAndEmitDAG(DAG);
+}
+
+SDNode *IA64DAGToDAGISel::SelectDIV(SDOperand Op) {
+  SDNode *N = Op.Val;
+  SDOperand Chain = N->getOperand(0);
+  SDOperand Tmp1 = N->getOperand(0);
+  SDOperand Tmp2 = N->getOperand(1);
+  AddToISelQueue(Chain);
+
+  AddToISelQueue(Tmp1);
+  AddToISelQueue(Tmp2);
+
+  bool isFP=false;
+
+  if(MVT::isFloatingPoint(Tmp1.getValueType()))
+    isFP=true;
+    
+  bool isModulus=false; // is it a division or a modulus?
+  bool isSigned=false;
+
+  switch(N->getOpcode()) {
+    case ISD::FDIV:
+    case ISD::SDIV:  isModulus=false; isSigned=true;  break;
+    case ISD::UDIV:  isModulus=false; isSigned=false; break;
+    case ISD::FREM:
+    case ISD::SREM:  isModulus=true;  isSigned=true;  break;
+    case ISD::UREM:  isModulus=true;  isSigned=false; break;
+  }
+
+  // TODO: check for integer divides by powers of 2 (or other simple patterns?)
+
+    SDOperand TmpPR, TmpPR2;
+    SDOperand TmpF1, TmpF2, TmpF3, TmpF4, TmpF5, TmpF6, TmpF7, TmpF8;
+    SDOperand TmpF9, TmpF10,TmpF11,TmpF12,TmpF13,TmpF14,TmpF15;
+    SDNode *Result;
+
+    // we'll need copies of F0 and F1
+    SDOperand F0 = CurDAG->getRegister(IA64::F0, MVT::f64);
+    SDOperand F1 = CurDAG->getRegister(IA64::F1, MVT::f64);
+    
+    // OK, emit some code:
+
+    if(!isFP) {
+      // first, load the inputs into FP regs.
+      TmpF1 =
+        SDOperand(CurDAG->getTargetNode(IA64::SETFSIG, MVT::f64, Tmp1), 0);
+      Chain = TmpF1.getValue(1);
+      TmpF2 =
+        SDOperand(CurDAG->getTargetNode(IA64::SETFSIG, MVT::f64, Tmp2), 0);
+      Chain = TmpF2.getValue(1);
+      
+      // next, convert the inputs to FP
+      if(isSigned) {
+        TmpF3 =
+          SDOperand(CurDAG->getTargetNode(IA64::FCVTXF, MVT::f64, TmpF1), 0);
+        Chain = TmpF3.getValue(1);
+        TmpF4 =
+          SDOperand(CurDAG->getTargetNode(IA64::FCVTXF, MVT::f64, TmpF2), 0);
+        Chain = TmpF4.getValue(1);
+      } else { // is unsigned
+        TmpF3 =
+          SDOperand(CurDAG->getTargetNode(IA64::FCVTXUFS1, MVT::f64, TmpF1), 0);
+        Chain = TmpF3.getValue(1);
+        TmpF4 =
+          SDOperand(CurDAG->getTargetNode(IA64::FCVTXUFS1, MVT::f64, TmpF2), 0);
+        Chain = TmpF4.getValue(1);
+      }
+
+    } else { // this is an FP divide/remainder, so we 'leak' some temp
+             // regs and assign TmpF3=Tmp1, TmpF4=Tmp2
+      TmpF3=Tmp1;
+      TmpF4=Tmp2;
+    }
+
+    // we start by computing an approximate reciprocal (good to 9 bits?)
+    // note, this instruction writes _both_ TmpF5 (answer) and TmpPR (predicate)
+    if(isFP)
+      TmpF5 = SDOperand(CurDAG->getTargetNode(IA64::FRCPAS0, MVT::f64, MVT::i1,
+                                              TmpF3, TmpF4), 0);
+    else
+      TmpF5 = SDOperand(CurDAG->getTargetNode(IA64::FRCPAS1, MVT::f64, MVT::i1,
+                                              TmpF3, TmpF4), 0);
+                                  
+    TmpPR = TmpF5.getValue(1);
+    Chain = TmpF5.getValue(2);
+
+    SDOperand minusB;
+    if(isModulus) { // for remainders, it'll be handy to have
+                             // copies of -input_b
+      minusB = SDOperand(CurDAG->getTargetNode(IA64::SUB, MVT::i64,
+                  CurDAG->getRegister(IA64::r0, MVT::i64), Tmp2), 0);
+      Chain = minusB.getValue(1);
+    }
+    
+    SDOperand TmpE0, TmpY1, TmpE1, TmpY2;
+
+    SDOperand OpsE0[] = { TmpF4, TmpF5, F1, TmpPR };
+    TmpE0 = SDOperand(CurDAG->getTargetNode(IA64::CFNMAS1, MVT::f64,
+                                            OpsE0, 4), 0);
+    Chain = TmpE0.getValue(1);
+    SDOperand OpsY1[] = { TmpF5, TmpE0, TmpF5, TmpPR };
+    TmpY1 = SDOperand(CurDAG->getTargetNode(IA64::CFMAS1, MVT::f64,
+                                            OpsY1, 4), 0);
+    Chain = TmpY1.getValue(1);
+    SDOperand OpsE1[] = { TmpE0, TmpE0, F0, TmpPR };
+    TmpE1 = SDOperand(CurDAG->getTargetNode(IA64::CFMAS1, MVT::f64,
+                                            OpsE1, 4), 0);
+    Chain = TmpE1.getValue(1);
+    SDOperand OpsY2[] = { TmpY1, TmpE1, TmpY1, TmpPR };
+    TmpY2 = SDOperand(CurDAG->getTargetNode(IA64::CFMAS1, MVT::f64,
+                                            OpsY2, 4), 0);
+    Chain = TmpY2.getValue(1);
+    
+    if(isFP) { // if this is an FP divide, we finish up here and exit early
+      if(isModulus)
+        assert(0 && "Sorry, try another FORTRAN compiler.");
+ 
+      SDOperand TmpE2, TmpY3, TmpQ0, TmpR0;
+
+      SDOperand OpsE2[] = { TmpE1, TmpE1, F0, TmpPR };
+      TmpE2 = SDOperand(CurDAG->getTargetNode(IA64::CFMAS1, MVT::f64,
+                                              OpsE2, 4), 0);
+      Chain = TmpE2.getValue(1);
+      SDOperand OpsY3[] = { TmpY2, TmpE2, TmpY2, TmpPR };
+      TmpY3 = SDOperand(CurDAG->getTargetNode(IA64::CFMAS1, MVT::f64,
+                                              OpsY3, 4), 0);
+      Chain = TmpY3.getValue(1);
+      SDOperand OpsQ0[] = { Tmp1, TmpY3, F0, TmpPR };
+      TmpQ0 =
+        SDOperand(CurDAG->getTargetNode(IA64::CFMADS1, MVT::f64, // double prec!
+                                        OpsQ0, 4), 0);
+      Chain = TmpQ0.getValue(1);
+      SDOperand OpsR0[] = { Tmp2, TmpQ0, Tmp1, TmpPR };
+      TmpR0 =
+        SDOperand(CurDAG->getTargetNode(IA64::CFNMADS1, MVT::f64, // double prec!
+                                        OpsR0, 4), 0);
+      Chain = TmpR0.getValue(1);
+
+// we want Result to have the same target register as the frcpa, so
+// we two-address hack it. See the comment "for this to work..." on
+// page 48 of Intel application note #245415
+      SDOperand Ops[] = { TmpF5, TmpY3, TmpR0, TmpQ0, TmpPR };
+      Result = CurDAG->getTargetNode(IA64::TCFMADS0, MVT::f64, // d.p. s0 rndg!
+                                     Ops, 5);
+      Chain = SDOperand(Result, 1);
+      return Result; // XXX: early exit!
+    } else { // this is *not* an FP divide, so there's a bit left to do:
+    
+      SDOperand TmpQ2, TmpR2, TmpQ3, TmpQ;
+
+      SDOperand OpsQ2[] = { TmpF3, TmpY2, F0, TmpPR };
+      TmpQ2 = SDOperand(CurDAG->getTargetNode(IA64::CFMAS1, MVT::f64,
+                                              OpsQ2, 4), 0);
+      Chain = TmpQ2.getValue(1);
+      SDOperand OpsR2[] = { TmpF4, TmpQ2, TmpF3, TmpPR };
+      TmpR2 = SDOperand(CurDAG->getTargetNode(IA64::CFNMAS1, MVT::f64,
+                                              OpsR2, 4), 0);
+      Chain = TmpR2.getValue(1);
+      
+// we want TmpQ3 to have the same target register as the frcpa? maybe we
+// should two-address hack it. See the comment "for this to work..." on page
+// 48 of Intel application note #245415
+      SDOperand OpsQ3[] = { TmpF5, TmpR2, TmpY2, TmpQ2, TmpPR };
+      TmpQ3 = SDOperand(CurDAG->getTargetNode(IA64::TCFMAS1, MVT::f64,
+                                         OpsQ3, 5), 0);
+      Chain = TmpQ3.getValue(1);
+
+      // STORY: without these two-address instructions (TCFMAS1 and TCFMADS0)
+      // the FPSWA won't be able to help out in the case of large/tiny
+      // arguments. Other fun bugs may also appear, e.g. 0/x = x, not 0.
+      
+      if(isSigned)
+        TmpQ = SDOperand(CurDAG->getTargetNode(IA64::FCVTFXTRUNCS1,
+                                               MVT::f64, TmpQ3), 0);
+      else
+        TmpQ = SDOperand(CurDAG->getTargetNode(IA64::FCVTFXUTRUNCS1,
+                                               MVT::f64, TmpQ3), 0);
+      
+      Chain = TmpQ.getValue(1);
+
+      if(isModulus) {
+        SDOperand FPminusB =
+          SDOperand(CurDAG->getTargetNode(IA64::SETFSIG, MVT::f64, minusB), 0);
+        Chain = FPminusB.getValue(1);
+        SDOperand Remainder =
+          SDOperand(CurDAG->getTargetNode(IA64::XMAL, MVT::f64,
+                                          TmpQ, FPminusB, TmpF1), 0);
+        Chain = Remainder.getValue(1);
+        Result = CurDAG->getTargetNode(IA64::GETFSIG, MVT::i64, Remainder);
+        Chain = SDOperand(Result, 1);
+      } else { // just an integer divide
+        Result = CurDAG->getTargetNode(IA64::GETFSIG, MVT::i64, TmpQ);
+        Chain = SDOperand(Result, 1);
+      }
+
+      return Result;
+    } // wasn't an FP divide
+}
+
+// Select - Convert the specified operand from a target-independent to a
+// target-specific node if it hasn't already been changed.
+SDNode *IA64DAGToDAGISel::Select(SDOperand Op) {
+  SDNode *N = Op.Val;
+  if (N->getOpcode() >= ISD::BUILTIN_OP_END &&
+      N->getOpcode() < IA64ISD::FIRST_NUMBER)
+    return NULL;   // Already selected.
+
+  switch (N->getOpcode()) {
+  default: break;
+
+  case IA64ISD::BRCALL: { // XXX: this is also a hack!
+    SDOperand Chain = N->getOperand(0);
+    SDOperand InFlag;  // Null incoming flag value.
+
+    AddToISelQueue(Chain);
+    if(N->getNumOperands()==3) { // we have an incoming chain, callee and flag
+      InFlag = N->getOperand(2);
+      AddToISelQueue(InFlag);
+    }
+
+    unsigned CallOpcode;
+    SDOperand CallOperand;
+    
+    // if we can call directly, do so
+    if (GlobalAddressSDNode *GASD =
+      dyn_cast<GlobalAddressSDNode>(N->getOperand(1))) {
+      CallOpcode = IA64::BRCALL_IPREL_GA;
+      CallOperand = CurDAG->getTargetGlobalAddress(GASD->getGlobal(), MVT::i64);
+    } else if (isa<ExternalSymbolSDNode>(N->getOperand(1))) {
+      // FIXME: we currently NEED this case for correctness, to avoid
+      // "non-pic code with imm reloc.n against dynamic symbol" errors
+    CallOpcode = IA64::BRCALL_IPREL_ES;
+    CallOperand = N->getOperand(1);
+  } else {
+    // otherwise we need to load the function descriptor,
+    // load the branch target (function)'s entry point and GP,
+    // branch (call) then restore the GP
+    SDOperand FnDescriptor = N->getOperand(1);
+    AddToISelQueue(FnDescriptor);
+   
+    // load the branch target's entry point [mem] and 
+    // GP value [mem+8]
+    SDOperand targetEntryPoint=
+      SDOperand(CurDAG->getTargetNode(IA64::LD8, MVT::i64, FnDescriptor), 0);
+    Chain = targetEntryPoint.getValue(1);
+    SDOperand targetGPAddr=
+      SDOperand(CurDAG->getTargetNode(IA64::ADDS, MVT::i64, 
+                                      FnDescriptor,
+                                      CurDAG->getConstant(8, MVT::i64)), 0);
+    Chain = targetGPAddr.getValue(1);
+    SDOperand targetGP =
+      SDOperand(CurDAG->getTargetNode(IA64::LD8, MVT::i64, targetGPAddr), 0);
+    Chain = targetGP.getValue(1);
+
+    Chain = CurDAG->getCopyToReg(Chain, IA64::r1, targetGP, InFlag);
+    InFlag = Chain.getValue(1);
+    Chain = CurDAG->getCopyToReg(Chain, IA64::B6, targetEntryPoint, InFlag); // FLAG these?
+    InFlag = Chain.getValue(1);
+    
+    CallOperand = CurDAG->getRegister(IA64::B6, MVT::i64);
+    CallOpcode = IA64::BRCALL_INDIRECT;
+  }
+ 
+   // Finally, once everything is setup, emit the call itself
+   if(InFlag.Val)
+     Chain = SDOperand(CurDAG->getTargetNode(CallOpcode, MVT::Other, MVT::Flag,
+                                             CallOperand, InFlag), 0);
+   else // there might be no arguments
+     Chain = SDOperand(CurDAG->getTargetNode(CallOpcode, MVT::Other, MVT::Flag,
+                                             CallOperand, Chain), 0);
+   InFlag = Chain.getValue(1);
+
+   std::vector<SDOperand> CallResults;
+
+   CallResults.push_back(Chain);
+   CallResults.push_back(InFlag);
+
+   for (unsigned i = 0, e = CallResults.size(); i != e; ++i)
+     ReplaceUses(Op.getValue(i), CallResults[i]);
+   return NULL;
+  }
+  
+  case IA64ISD::GETFD: {
+    SDOperand Input = N->getOperand(0);
+    AddToISelQueue(Input);
+    return CurDAG->getTargetNode(IA64::GETFD, MVT::i64, Input);
+  } 
+  
+  case ISD::FDIV:
+  case ISD::SDIV:
+  case ISD::UDIV:
+  case ISD::SREM:
+  case ISD::UREM:
+    return SelectDIV(Op);
+ 
+  case ISD::TargetConstantFP: {
+    SDOperand Chain = CurDAG->getEntryNode(); // this is a constant, so..
+
+    SDOperand V;
+    if (cast<ConstantFPSDNode>(N)->isExactlyValue(+0.0)) {
+      V = CurDAG->getCopyFromReg(Chain, IA64::F0, MVT::f64);
+    } else if (cast<ConstantFPSDNode>(N)->isExactlyValue(+1.0)) {
+      V = CurDAG->getCopyFromReg(Chain, IA64::F1, MVT::f64);
+    } else
+      assert(0 && "Unexpected FP constant!");
+    
+    ReplaceUses(SDOperand(N, 0), V);
+    return 0;
+  }
+
+  case ISD::FrameIndex: { // TODO: reduce creepyness
+    int FI = cast<FrameIndexSDNode>(N)->getIndex();
+    if (N->hasOneUse())
+      return CurDAG->SelectNodeTo(N, IA64::MOV, MVT::i64,
+                                  CurDAG->getTargetFrameIndex(FI, MVT::i64));
+    else
+      return CurDAG->getTargetNode(IA64::MOV, MVT::i64,
+                                   CurDAG->getTargetFrameIndex(FI, MVT::i64));
+  }
+
+  case ISD::ConstantPool: { // TODO: nuke the constant pool
+    // (ia64 doesn't need one)
+    ConstantPoolSDNode *CP = cast<ConstantPoolSDNode>(N);
+    Constant *C = CP->getConstVal();
+    SDOperand CPI = CurDAG->getTargetConstantPool(C, MVT::i64,
+                                                  CP->getAlignment());
+    return CurDAG->getTargetNode(IA64::ADDL_GA, MVT::i64, // ?
+                                 CurDAG->getRegister(IA64::r1, MVT::i64), CPI);
+  }
+
+  case ISD::GlobalAddress: {
+    GlobalValue *GV = cast<GlobalAddressSDNode>(N)->getGlobal();
+    SDOperand GA = CurDAG->getTargetGlobalAddress(GV, MVT::i64);
+    SDOperand Tmp =
+      SDOperand(CurDAG->getTargetNode(IA64::ADDL_GA, MVT::i64, 
+                                      CurDAG->getRegister(IA64::r1,
+                                                          MVT::i64), GA), 0);
+    return CurDAG->getTargetNode(IA64::LD8, MVT::i64, Tmp);
+  }
+  
+/* XXX
+   case ISD::ExternalSymbol: {
+     SDOperand EA = CurDAG->getTargetExternalSymbol(
+       cast<ExternalSymbolSDNode>(N)->getSymbol(),
+       MVT::i64);
+     SDOperand Tmp = CurDAG->getTargetNode(IA64::ADDL_EA, MVT::i64, 
+                                           CurDAG->getRegister(IA64::r1,
+                                                               MVT::i64),
+                                           EA);
+     return CurDAG->getTargetNode(IA64::LD8, MVT::i64, Tmp);
+   }
+*/
+
+  case ISD::LOAD: { // FIXME: load -1, not 1, for bools?
+    LoadSDNode *LD = cast<LoadSDNode>(N);
+    SDOperand Chain = LD->getChain();
+    SDOperand Address = LD->getBasePtr();
+    AddToISelQueue(Chain);
+    AddToISelQueue(Address);
+
+    MVT::ValueType TypeBeingLoaded = LD->getLoadedVT();
+    unsigned Opc;
+    switch (TypeBeingLoaded) {
+    default:
+#ifndef NDEBUG
+      N->dump(CurDAG);
+#endif
+      assert(0 && "Cannot load this type!");
+    case MVT::i1: { // this is a bool
+      Opc = IA64::LD1; // first we load a byte, then compare for != 0
+      if(N->getValueType(0) == MVT::i1) { // XXX: early exit!
+        return CurDAG->SelectNodeTo(N, IA64::CMPNE, MVT::i1, MVT::Other, 
+                    SDOperand(CurDAG->getTargetNode(Opc, MVT::i64, Address), 0),
+                                    CurDAG->getRegister(IA64::r0, MVT::i64), 
+                                    Chain);
+      }
+      /* otherwise, we want to load a bool into something bigger: LD1
+         will do that for us, so we just fall through */
+    }
+    case MVT::i8:  Opc = IA64::LD1; break;
+    case MVT::i16: Opc = IA64::LD2; break;
+    case MVT::i32: Opc = IA64::LD4; break;
+    case MVT::i64: Opc = IA64::LD8; break;
+    
+    case MVT::f32: Opc = IA64::LDF4; break;
+    case MVT::f64: Opc = IA64::LDF8; break;
+    }
+
+    // TODO: comment this
+    return CurDAG->SelectNodeTo(N, Opc, N->getValueType(0), MVT::Other,
+                                Address, Chain);
+  }
+  
+  case ISD::STORE: {
+    StoreSDNode *ST = cast<StoreSDNode>(N);
+    SDOperand Address = ST->getBasePtr();
+    SDOperand Chain = ST->getChain();
+    AddToISelQueue(Address);
+    AddToISelQueue(Chain);
+   
+    unsigned Opc;
+    if (ISD::isNON_TRUNCStore(N)) {
+      switch (N->getOperand(1).getValueType()) {
+      default: assert(0 && "unknown type in store");
+      case MVT::i1: { // this is a bool
+        Opc = IA64::ST1; // we store either 0 or 1 as a byte 
+        // first load zero!
+        SDOperand Initial = CurDAG->getCopyFromReg(Chain, IA64::r0, MVT::i64);
+        Chain = Initial.getValue(1);
+        // then load 1 into the same reg iff the predicate to store is 1
+        SDOperand Tmp = ST->getValue();
+        AddToISelQueue(Tmp);
+        Tmp =
+          SDOperand(CurDAG->getTargetNode(IA64::TPCADDS, MVT::i64, Initial,
+                                          CurDAG->getTargetConstant(1, MVT::i64),
+                                          Tmp), 0);
+        return CurDAG->SelectNodeTo(N, Opc, MVT::Other, Address, Tmp, Chain);
+      }
+      case MVT::i64: Opc = IA64::ST8;  break;
+      case MVT::f64: Opc = IA64::STF8; break;
+      }
+    } else { // Truncating store
+      switch(ST->getStoredVT()) {
+      default: assert(0 && "unknown type in truncstore");
+      case MVT::i8:  Opc = IA64::ST1;  break;
+      case MVT::i16: Opc = IA64::ST2;  break;
+      case MVT::i32: Opc = IA64::ST4;  break;
+      case MVT::f32: Opc = IA64::STF4; break;
+      }
+    }
+    
+    SDOperand N1 = N->getOperand(1);
+    SDOperand N2 = N->getOperand(2);
+    AddToISelQueue(N1);
+    AddToISelQueue(N2);
+    return CurDAG->SelectNodeTo(N, Opc, MVT::Other, N2, N1, Chain);
+  }
+
+  case ISD::BRCOND: {
+    SDOperand Chain = N->getOperand(0);
+    SDOperand CC = N->getOperand(1);
+    AddToISelQueue(Chain);
+    AddToISelQueue(CC);
+    MachineBasicBlock *Dest =
+      cast<BasicBlockSDNode>(N->getOperand(2))->getBasicBlock();
+    //FIXME - we do NOT need long branches all the time
+    return CurDAG->SelectNodeTo(N, IA64::BRLCOND_NOTCALL, MVT::Other, CC, 
+                                CurDAG->getBasicBlock(Dest), Chain);
+  }
+
+  case ISD::CALLSEQ_START:
+  case ISD::CALLSEQ_END: {
+    int64_t Amt = cast<ConstantSDNode>(N->getOperand(1))->getValue();
+    unsigned Opc = N->getOpcode() == ISD::CALLSEQ_START ?
+      IA64::ADJUSTCALLSTACKDOWN : IA64::ADJUSTCALLSTACKUP;
+    SDOperand N0 = N->getOperand(0);
+    AddToISelQueue(N0);
+    return CurDAG->SelectNodeTo(N, Opc, MVT::Other, getI64Imm(Amt), N0);
+  }
+
+  case ISD::BR:
+    // FIXME: we don't need long branches all the time!
+    SDOperand N0 = N->getOperand(0);
+    AddToISelQueue(N0);
+    return CurDAG->SelectNodeTo(N, IA64::BRL_NOTCALL, MVT::Other, 
+                                N->getOperand(1), N0);
+  }
+  
+  return SelectCode(Op);
+}
+
+
+/// createIA64DAGToDAGInstructionSelector - This pass converts a legalized DAG
+/// into an IA64-specific DAG, ready for instruction scheduling.
+///
+FunctionPass
+*llvm::createIA64DAGToDAGInstructionSelector(IA64TargetMachine &TM) {
+  return new IA64DAGToDAGISel(TM);
+}
+