Move the FunctionLoweringInfo class and some related utility functions out

of SelectionDAGBuild.h/cpp into its own files, to help separate
general lowering logic from SelectionDAG-specific lowering logic.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89667 91177308-0d34-0410-b5e6-96231b3b80d8

5 files changed, 419 insertions, 310 deletions

diff --git a/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp b/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
new file mode 100644
index 0000000000..964b71f0c7
--- /dev/null
+++ b/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
@@ -0,0 +1,278 @@
+//===-- FunctionLoweringInfo.cpp ------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This implements routines for translating functions from LLVM IR into
+// Machine IR.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "function-lowering-info"
+#include "FunctionLoweringInfo.h"
+#include "llvm/CallingConv.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/Function.h"
+#include "llvm/Instructions.h"
+#include "llvm/LLVMContext.h"
+#include "llvm/Module.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineModuleInfo.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/Analysis/DebugInfo.h"
+#include "llvm/Target/TargetRegisterInfo.h"
+#include "llvm/Target/TargetData.h"
+#include "llvm/Target/TargetFrameInfo.h"
+#include "llvm/Target/TargetInstrInfo.h"
+#include "llvm/Target/TargetIntrinsicInfo.h"
+#include "llvm/Target/TargetLowering.h"
+#include "llvm/Target/TargetOptions.h"
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/MathExtras.h"
+#include "llvm/Support/raw_ostream.h"
+#include <algorithm>
+using namespace llvm;
+
+/// ComputeLinearIndex - Given an LLVM IR aggregate type and a sequence
+/// of insertvalue or extractvalue indices that identify a member, return
+/// the linearized index of the start of the member.
+///
+unsigned llvm::ComputeLinearIndex(const TargetLowering &TLI, const Type *Ty,
+                                  const unsigned *Indices,
+                                  const unsigned *IndicesEnd,
+                                  unsigned CurIndex) {
+  // Base case: We're done.
+  if (Indices && Indices == IndicesEnd)
+    return CurIndex;
+
+  // Given a struct type, recursively traverse the elements.
+  if (const StructType *STy = dyn_cast<StructType>(Ty)) {
+    for (StructType::element_iterator EB = STy->element_begin(),
+                                      EI = EB,
+                                      EE = STy->element_end();
+        EI != EE; ++EI) {
+      if (Indices && *Indices == unsigned(EI - EB))
+        return ComputeLinearIndex(TLI, *EI, Indices+1, IndicesEnd, CurIndex);
+      CurIndex = ComputeLinearIndex(TLI, *EI, 0, 0, CurIndex);
+    }
+    return CurIndex;
+  }
+  // Given an array type, recursively traverse the elements.
+  else if (const ArrayType *ATy = dyn_cast<ArrayType>(Ty)) {
+    const Type *EltTy = ATy->getElementType();
+    for (unsigned i = 0, e = ATy->getNumElements(); i != e; ++i) {
+      if (Indices && *Indices == i)
+        return ComputeLinearIndex(TLI, EltTy, Indices+1, IndicesEnd, CurIndex);
+      CurIndex = ComputeLinearIndex(TLI, EltTy, 0, 0, CurIndex);
+    }
+    return CurIndex;
+  }
+  // We haven't found the type we're looking for, so keep searching.
+  return CurIndex + 1;
+}
+
+/// ComputeValueVTs - Given an LLVM IR type, compute a sequence of
+/// EVTs that represent all the individual underlying
+/// non-aggregate types that comprise it.
+///
+/// If Offsets is non-null, it points to a vector to be filled in
+/// with the in-memory offsets of each of the individual values.
+///
+void llvm::ComputeValueVTs(const TargetLowering &TLI, const Type *Ty,
+                           SmallVectorImpl<EVT> &ValueVTs,
+                           SmallVectorImpl<uint64_t> *Offsets,
+                           uint64_t StartingOffset) {
+  // Given a struct type, recursively traverse the elements.
+  if (const StructType *STy = dyn_cast<StructType>(Ty)) {
+    const StructLayout *SL = TLI.getTargetData()->getStructLayout(STy);
+    for (StructType::element_iterator EB = STy->element_begin(),
+                                      EI = EB,
+                                      EE = STy->element_end();
+         EI != EE; ++EI)
+      ComputeValueVTs(TLI, *EI, ValueVTs, Offsets,
+                      StartingOffset + SL->getElementOffset(EI - EB));
+    return;
+  }
+  // Given an array type, recursively traverse the elements.
+  if (const ArrayType *ATy = dyn_cast<ArrayType>(Ty)) {
+    const Type *EltTy = ATy->getElementType();
+    uint64_t EltSize = TLI.getTargetData()->getTypeAllocSize(EltTy);
+    for (unsigned i = 0, e = ATy->getNumElements(); i != e; ++i)
+      ComputeValueVTs(TLI, EltTy, ValueVTs, Offsets,
+                      StartingOffset + i * EltSize);
+    return;
+  }
+  // Interpret void as zero return values.
+  if (Ty == Type::getVoidTy(Ty->getContext()))
+    return;
+  // Base case: we can get an EVT for this LLVM IR type.
+  ValueVTs.push_back(TLI.getValueType(Ty));
+  if (Offsets)
+    Offsets->push_back(StartingOffset);
+}
+
+/// isUsedOutsideOfDefiningBlock - Return true if this instruction is used by
+/// PHI nodes or outside of the basic block that defines it, or used by a
+/// switch or atomic instruction, which may expand to multiple basic blocks.
+static bool isUsedOutsideOfDefiningBlock(Instruction *I) {
+  if (isa<PHINode>(I)) return true;
+  BasicBlock *BB = I->getParent();
+  for (Value::use_iterator UI = I->use_begin(), E = I->use_end(); UI != E; ++UI)
+    if (cast<Instruction>(*UI)->getParent() != BB || isa<PHINode>(*UI))
+      return true;
+  return false;
+}
+
+/// isOnlyUsedInEntryBlock - If the specified argument is only used in the
+/// entry block, return true.  This includes arguments used by switches, since
+/// the switch may expand into multiple basic blocks.
+static bool isOnlyUsedInEntryBlock(Argument *A, bool EnableFastISel) {
+  // With FastISel active, we may be splitting blocks, so force creation
+  // of virtual registers for all non-dead arguments.
+  // Don't force virtual registers for byval arguments though, because
+  // fast-isel can't handle those in all cases.
+  if (EnableFastISel && !A->hasByValAttr())
+    return A->use_empty();
+
+  BasicBlock *Entry = A->getParent()->begin();
+  for (Value::use_iterator UI = A->use_begin(), E = A->use_end(); UI != E; ++UI)
+    if (cast<Instruction>(*UI)->getParent() != Entry || isa<SwitchInst>(*UI))
+      return false;  // Use not in entry block.
+  return true;
+}
+
+FunctionLoweringInfo::FunctionLoweringInfo(TargetLowering &tli)
+  : TLI(tli) {
+}
+
+void FunctionLoweringInfo::set(Function &fn, MachineFunction &mf,
+                               bool EnableFastISel) {
+  Fn = &fn;
+  MF = &mf;
+  RegInfo = &MF->getRegInfo();
+
+  // Create a vreg for each argument register that is not dead and is used
+  // outside of the entry block for the function.
+  for (Function::arg_iterator AI = Fn->arg_begin(), E = Fn->arg_end();
+       AI != E; ++AI)
+    if (!isOnlyUsedInEntryBlock(AI, EnableFastISel))
+      InitializeRegForValue(AI);
+
+  // Initialize the mapping of values to registers.  This is only set up for
+  // instruction values that are used outside of the block that defines
+  // them.
+  Function::iterator BB = Fn->begin(), EB = Fn->end();
+  for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I)
+    if (AllocaInst *AI = dyn_cast<AllocaInst>(I))
+      if (ConstantInt *CUI = dyn_cast<ConstantInt>(AI->getArraySize())) {
+        const Type *Ty = AI->getAllocatedType();
+        uint64_t TySize = TLI.getTargetData()->getTypeAllocSize(Ty);
+        unsigned Align =
+          std::max((unsigned)TLI.getTargetData()->getPrefTypeAlignment(Ty),
+                   AI->getAlignment());
+
+        TySize *= CUI->getZExtValue();   // Get total allocated size.
+        if (TySize == 0) TySize = 1; // Don't create zero-sized stack objects.
+        StaticAllocaMap[AI] =
+          MF->getFrameInfo()->CreateStackObject(TySize, Align, false);
+      }
+
+  for (; BB != EB; ++BB)
+    for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I)
+      if (!I->use_empty() && isUsedOutsideOfDefiningBlock(I))
+        if (!isa<AllocaInst>(I) ||
+            !StaticAllocaMap.count(cast<AllocaInst>(I)))
+          InitializeRegForValue(I);
+
+  // Create an initial MachineBasicBlock for each LLVM BasicBlock in F.  This
+  // also creates the initial PHI MachineInstrs, though none of the input
+  // operands are populated.
+  for (BB = Fn->begin(), EB = Fn->end(); BB != EB; ++BB) {
+    MachineBasicBlock *MBB = mf.CreateMachineBasicBlock(BB);
+    MBBMap[BB] = MBB;
+    MF->push_back(MBB);
+
+    // Transfer the address-taken flag. This is necessary because there could
+    // be multiple MachineBasicBlocks corresponding to one BasicBlock, and only
+    // the first one should be marked.
+    if (BB->hasAddressTaken())
+      MBB->setHasAddressTaken();
+
+    // Create Machine PHI nodes for LLVM PHI nodes, lowering them as
+    // appropriate.
+    PHINode *PN;
+    DebugLoc DL;
+    for (BasicBlock::iterator
+           I = BB->begin(), E = BB->end(); I != E; ++I) {
+
+      PN = dyn_cast<PHINode>(I);
+      if (!PN || PN->use_empty()) continue;
+
+      unsigned PHIReg = ValueMap[PN];
+      assert(PHIReg && "PHI node does not have an assigned virtual register!");
+
+      SmallVector<EVT, 4> ValueVTs;
+      ComputeValueVTs(TLI, PN->getType(), ValueVTs);
+      for (unsigned vti = 0, vte = ValueVTs.size(); vti != vte; ++vti) {
+        EVT VT = ValueVTs[vti];
+        unsigned NumRegisters = TLI.getNumRegisters(Fn->getContext(), VT);
+        const TargetInstrInfo *TII = MF->getTarget().getInstrInfo();
+        for (unsigned i = 0; i != NumRegisters; ++i)
+          BuildMI(MBB, DL, TII->get(TargetInstrInfo::PHI), PHIReg + i);
+        PHIReg += NumRegisters;
+      }
+    }
+  }
+}
+
+/// clear - Clear out all the function-specific state. This returns this
+/// FunctionLoweringInfo to an empty state, ready to be used for a
+/// different function.
+void FunctionLoweringInfo::clear() {
+  MBBMap.clear();
+  ValueMap.clear();
+  StaticAllocaMap.clear();
+#ifndef NDEBUG
+  CatchInfoLost.clear();
+  CatchInfoFound.clear();
+#endif
+  LiveOutRegInfo.clear();
+}
+
+unsigned FunctionLoweringInfo::MakeReg(EVT VT) {
+  return RegInfo->createVirtualRegister(TLI.getRegClassFor(VT));
+}
+
+/// CreateRegForValue - Allocate the appropriate number of virtual registers of
+/// the correctly promoted or expanded types.  Assign these registers
+/// consecutive vreg numbers and return the first assigned number.
+///
+/// In the case that the given value has struct or array type, this function
+/// will assign registers for each member or element.
+///
+unsigned FunctionLoweringInfo::CreateRegForValue(const Value *V) {
+  SmallVector<EVT, 4> ValueVTs;
+  ComputeValueVTs(TLI, V->getType(), ValueVTs);
+
+  unsigned FirstReg = 0;
+  for (unsigned Value = 0, e = ValueVTs.size(); Value != e; ++Value) {
+    EVT ValueVT = ValueVTs[Value];
+    EVT RegisterVT = TLI.getRegisterType(V->getContext(), ValueVT);
+
+    unsigned NumRegs = TLI.getNumRegisters(V->getContext(), ValueVT);
+    for (unsigned i = 0; i != NumRegs; ++i) {
+      unsigned R = MakeReg(RegisterVT);
+      if (!FirstReg) FirstReg = R;
+    }
+  }
+  return FirstReg;
+}
diff --git a/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.h b/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.h
new file mode 100644
index 0000000000..09fc23f6ba
--- /dev/null
+++ b/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.h
@@ -0,0 +1,137 @@
+//===-- FunctionLoweringInfo.h - Lower functions from LLVM IR to CodeGen --===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This implements routines for translating functions from LLVM IR into
+// Machine IR.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef FUNCTIONLOWERINGINFO_H
+#define FUNCTIONLOWERINGINFO_H
+
+#include "llvm/ADT/APInt.h"
+#include "llvm/ADT/DenseMap.h"
+#ifndef NDEBUG
+#include "llvm/ADT/SmallSet.h"
+#endif
+#include "llvm/CodeGen/ValueTypes.h"
+#include <vector>
+
+namespace llvm {
+
+class AllocaInst;
+class BasicBlock;
+class Function;
+class Instruction;
+class MachineBasicBlock;
+class MachineFunction;
+class MachineRegisterInfo;
+class TargetLowering;
+class Value;
+
+//===--------------------------------------------------------------------===//
+/// FunctionLoweringInfo - This contains information that is global to a
+/// function that is used when lowering a region of the function.
+///
+class FunctionLoweringInfo {
+public:
+  TargetLowering &TLI;
+  Function *Fn;
+  MachineFunction *MF;
+  MachineRegisterInfo *RegInfo;
+
+  /// CanLowerReturn - true iff the function's return value can be lowered to
+  /// registers.
+  bool CanLowerReturn;
+
+  /// DemoteRegister - if CanLowerReturn is false, DemoteRegister is a vreg
+  /// allocated to hold a pointer to the hidden sret parameter.
+  unsigned DemoteRegister;
+
+  explicit FunctionLoweringInfo(TargetLowering &TLI);
+
+  /// set - Initialize this FunctionLoweringInfo with the given Function
+  /// and its associated MachineFunction.
+  ///
+  void set(Function &Fn, MachineFunction &MF, bool EnableFastISel);
+
+  /// MBBMap - A mapping from LLVM basic blocks to their machine code entry.
+  DenseMap<const BasicBlock*, MachineBasicBlock *> MBBMap;
+
+  /// ValueMap - Since we emit code for the function a basic block at a time,
+  /// we must remember which virtual registers hold the values for
+  /// cross-basic-block values.
+  DenseMap<const Value*, unsigned> ValueMap;
+
+  /// StaticAllocaMap - Keep track of frame indices for fixed sized allocas in
+  /// the entry block.  This allows the allocas to be efficiently referenced
+  /// anywhere in the function.
+  DenseMap<const AllocaInst*, int> StaticAllocaMap;
+
+#ifndef NDEBUG
+  SmallSet<Instruction*, 8> CatchInfoLost;
+  SmallSet<Instruction*, 8> CatchInfoFound;
+#endif
+
+  unsigned MakeReg(EVT VT);
+  
+  /// isExportedInst - Return true if the specified value is an instruction
+  /// exported from its block.
+  bool isExportedInst(const Value *V) {
+    return ValueMap.count(V);
+  }
+
+  unsigned CreateRegForValue(const Value *V);
+  
+  unsigned InitializeRegForValue(const Value *V) {
+    unsigned &R = ValueMap[V];
+    assert(R == 0 && "Already initialized this value register!");
+    return R = CreateRegForValue(V);
+  }
+  
+  struct LiveOutInfo {
+    unsigned NumSignBits;
+    APInt KnownOne, KnownZero;
+    LiveOutInfo() : NumSignBits(0), KnownOne(1, 0), KnownZero(1, 0) {}
+  };
+  
+  /// LiveOutRegInfo - Information about live out vregs, indexed by their
+  /// register number offset by 'FirstVirtualRegister'.
+  std::vector<LiveOutInfo> LiveOutRegInfo;
+
+  /// clear - Clear out all the function-specific state. This returns this
+  /// FunctionLoweringInfo to an empty state, ready to be used for a
+  /// different function.
+  void clear();
+};
+
+/// ComputeLinearIndex - Given an LLVM IR aggregate type and a sequence
+/// of insertvalue or extractvalue indices that identify a member, return
+/// the linearized index of the start of the member.
+///
+unsigned ComputeLinearIndex(const TargetLowering &TLI, const Type *Ty,
+                            const unsigned *Indices,
+                            const unsigned *IndicesEnd,
+                            unsigned CurIndex = 0);
+
+/// ComputeValueVTs - Given an LLVM IR type, compute a sequence of
+/// EVTs that represent all the individual underlying
+/// non-aggregate types that comprise it.
+///
+/// If Offsets is non-null, it points to a vector to be filled in
+/// with the in-memory offsets of each of the individual values.
+///
+void ComputeValueVTs(const TargetLowering &TLI, const Type *Ty,
+                     SmallVectorImpl<EVT> &ValueVTs,
+                     SmallVectorImpl<uint64_t> *Offsets = 0,
+                     uint64_t StartingOffset = 0);
+
+} // end namespace llvm
+
+#endif
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
index f953a74d9d..238a0366ec 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
@@ -13,11 +13,11 @@
 
 #define DEBUG_TYPE "isel"
 #include "SelectionDAGBuild.h"
+#include "FunctionLoweringInfo.h"
 #include "llvm/ADT/BitVector.h"
 #include "llvm/ADT/SmallSet.h"
 #include "llvm/Analysis/AliasAnalysis.h"
 #include "llvm/Constants.h"
-#include "llvm/Constants.h"
 #include "llvm/CallingConv.h"
 #include "llvm/DerivedTypes.h"
 #include "llvm/Function.h"
@@ -68,84 +68,6 @@ LimitFPPrecision("limit-float-precision",
                  cl::location(LimitFloatPrecision),
                  cl::init(0));
 
-/// ComputeLinearIndex - Given an LLVM IR aggregate type and a sequence
-/// of insertvalue or extractvalue indices that identify a member, return
-/// the linearized index of the start of the member.
-///
-static unsigned ComputeLinearIndex(const TargetLowering &TLI, const Type *Ty,
-                                   const unsigned *Indices,
-                                   const unsigned *IndicesEnd,
-                                   unsigned CurIndex = 0) {
-  // Base case: We're done.
-  if (Indices && Indices == IndicesEnd)
-    return CurIndex;
-
-  // Given a struct type, recursively traverse the elements.
-  if (const StructType *STy = dyn_cast<StructType>(Ty)) {
-    for (StructType::element_iterator EB = STy->element_begin(),
-                                      EI = EB,
-                                      EE = STy->element_end();
-        EI != EE; ++EI) {
-      if (Indices && *Indices == unsigned(EI - EB))
-        return ComputeLinearIndex(TLI, *EI, Indices+1, IndicesEnd, CurIndex);
-      CurIndex = ComputeLinearIndex(TLI, *EI, 0, 0, CurIndex);
-    }
-    return CurIndex;
-  }
-  // Given an array type, recursively traverse the elements.
-  else if (const ArrayType *ATy = dyn_cast<ArrayType>(Ty)) {
-    const Type *EltTy = ATy->getElementType();
-    for (unsigned i = 0, e = ATy->getNumElements(); i != e; ++i) {
-      if (Indices && *Indices == i)
-        return ComputeLinearIndex(TLI, EltTy, Indices+1, IndicesEnd, CurIndex);
-      CurIndex = ComputeLinearIndex(TLI, EltTy, 0, 0, CurIndex);
-    }
-    return CurIndex;
-  }
-  // We haven't found the type we're looking for, so keep searching.
-  return CurIndex + 1;
-}
-
-/// ComputeValueVTs - Given an LLVM IR type, compute a sequence of
-/// EVTs that represent all the individual underlying
-/// non-aggregate types that comprise it.
-///
-/// If Offsets is non-null, it points to a vector to be filled in
-/// with the in-memory offsets of each of the individual values.
-///
-static void ComputeValueVTs(const TargetLowering &TLI, const Type *Ty,
-                            SmallVectorImpl<EVT> &ValueVTs,
-                            SmallVectorImpl<uint64_t> *Offsets = 0,
-                            uint64_t StartingOffset = 0) {
-  // Given a struct type, recursively traverse the elements.
-  if (const StructType *STy = dyn_cast<StructType>(Ty)) {
-    const StructLayout *SL = TLI.getTargetData()->getStructLayout(STy);
-    for (StructType::element_iterator EB = STy->element_begin(),
-                                      EI = EB,
-                                      EE = STy->element_end();
-         EI != EE; ++EI)
-      ComputeValueVTs(TLI, *EI, ValueVTs, Offsets,
-                      StartingOffset + SL->getElementOffset(EI - EB));
-    return;
-  }
-  // Given an array type, recursively traverse the elements.
-  if (const ArrayType *ATy = dyn_cast<ArrayType>(Ty)) {
-    const Type *EltTy = ATy->getElementType();
-    uint64_t EltSize = TLI.getTargetData()->getTypeAllocSize(EltTy);
-    for (unsigned i = 0, e = ATy->getNumElements(); i != e; ++i)
-      ComputeValueVTs(TLI, EltTy, ValueVTs, Offsets,
-                      StartingOffset + i * EltSize);
-    return;
-  }
-  // Interpret void as zero return values.
-  if (Ty == Type::getVoidTy(Ty->getContext()))
-    return;
-  // Base case: we can get an EVT for this LLVM IR type.
-  ValueVTs.push_back(TLI.getValueType(Ty));
-  if (Offsets)
-    Offsets->push_back(StartingOffset);
-}
-
 namespace llvm {
   /// RegsForValue - This struct represents the registers (physical or virtual)
   /// that a particular set of values is assigned, and the type information about
@@ -241,150 +163,6 @@ namespace llvm {
   };
 }
 
-/// isUsedOutsideOfDefiningBlock - Return true if this instruction is used by
-/// PHI nodes or outside of the basic block that defines it, or used by a
-/// switch or atomic instruction, which may expand to multiple basic blocks.
-static bool isUsedOutsideOfDefiningBlock(Instruction *I) {
-  if (isa<PHINode>(I)) return true;
-  BasicBlock *BB = I->getParent();
-  for (Value::use_iterator UI = I->use_begin(), E = I->use_end(); UI != E; ++UI)
-    if (cast<Instruction>(*UI)->getParent() != BB || isa<PHINode>(*UI))
-      return true;
-  return false;
-}
-
-/// isOnlyUsedInEntryBlock - If the specified argument is only used in the
-/// entry block, return true.  This includes arguments used by switches, since
-/// the switch may expand into multiple basic blocks.
-static bool isOnlyUsedInEntryBlock(Argument *A, bool EnableFastISel) {
-  // With FastISel active, we may be splitting blocks, so force creation
-  // of virtual registers for all non-dead arguments.
-  // Don't force virtual registers for byval arguments though, because
-  // fast-isel can't handle those in all cases.
-  if (EnableFastISel && !A->hasByValAttr())
-    return A->use_empty();
-
-  BasicBlock *Entry = A->getParent()->begin();
-  for (Value::use_iterator UI = A->use_begin(), E = A->use_end(); UI != E; ++UI)
-    if (cast<Instruction>(*UI)->getParent() != Entry || isa<SwitchInst>(*UI))
-      return false;  // Use not in entry block.
-  return true;
-}
-
-FunctionLoweringInfo::FunctionLoweringInfo(TargetLowering &tli)
-  : TLI(tli) {
-}
-
-void FunctionLoweringInfo::set(Function &fn, MachineFunction &mf,
-                               SelectionDAG &DAG,
-                               bool EnableFastISel) {
-  Fn = &fn;
-  MF = &mf;
-  RegInfo = &MF->getRegInfo();
-
-  // Create a vreg for each argument register that is not dead and is used
-  // outside of the entry block for the function.
-  for (Function::arg_iterator AI = Fn->arg_begin(), E = Fn->arg_end();
-       AI != E; ++AI)
-    if (!isOnlyUsedInEntryBlock(AI, EnableFastISel))
-      InitializeRegForValue(AI);
-
-  // Initialize the mapping of values to registers.  This is only set up for
-  // instruction values that are used outside of the block that defines
-  // them.
-  Function::iterator BB = Fn->begin(), EB = Fn->end();
-  for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I)
-    if (AllocaInst *AI = dyn_cast<AllocaInst>(I))
-      if (ConstantInt *CUI = dyn_cast<ConstantInt>(AI->getArraySize())) {
-        const Type *Ty = AI->getAllocatedType();
-        uint64_t TySize = TLI.getTargetData()->getTypeAllocSize(Ty);
-        unsigned Align =
-          std::max((unsigned)TLI.getTargetData()->getPrefTypeAlignment(Ty),
-                   AI->getAlignment());
-
-        TySize *= CUI->getZExtValue();   // Get total allocated size.
-        if (TySize == 0) TySize = 1; // Don't create zero-sized stack objects.
-        StaticAllocaMap[AI] =
-          MF->getFrameInfo()->CreateStackObject(TySize, Align, false);
-      }
-
-  for (; BB != EB; ++BB)
-    for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I)
-      if (!I->use_empty() && isUsedOutsideOfDefiningBlock(I))
-        if (!isa<AllocaInst>(I) ||
-            !StaticAllocaMap.count(cast<AllocaInst>(I)))
-          InitializeRegForValue(I);
-
-  // Create an initial MachineBasicBlock for each LLVM BasicBlock in F.  This
-  // also creates the initial PHI MachineInstrs, though none of the input
-  // operands are populated.
-  for (BB = Fn->begin(), EB = Fn->end(); BB != EB; ++BB) {
-    MachineBasicBlock *MBB = mf.CreateMachineBasicBlock(BB);
-    MBBMap[BB] = MBB;
-    MF->push_back(MBB);
-
-    // Transfer the address-taken flag. This is necessary because there could
-    // be multiple MachineBasicBlocks corresponding to one BasicBlock, and only
-    // the first one should be marked.
-    if (BB->hasAddressTaken())
-      MBB->setHasAddressTaken();
-
-    // Create Machine PHI nodes for LLVM PHI nodes, lowering them as
-    // appropriate.
-    PHINode *PN;
-    DebugLoc DL;
-    for (BasicBlock::iterator
-           I = BB->begin(), E = BB->end(); I != E; ++I) {
-
-      PN = dyn_cast<PHINode>(I);
-      if (!PN || PN->use_empty()) continue;
-
-      unsigned PHIReg = ValueMap[PN];
-      assert(PHIReg && "PHI node does not have an assigned virtual register!");
-
-      SmallVector<EVT, 4> ValueVTs;
-      ComputeValueVTs(TLI, PN->getType(), ValueVTs);
-      for (unsigned vti = 0, vte = ValueVTs.size(); vti != vte; ++vti) {
-        EVT VT = ValueVTs[vti];
-        unsigned NumRegisters = TLI.getNumRegisters(*DAG.getContext(), VT);
-        const TargetInstrInfo *TII = MF->getTarget().getInstrInfo();
-        for (unsigned i = 0; i != NumRegisters; ++i)
-          BuildMI(MBB, DL, TII->get(TargetInstrInfo::PHI), PHIReg + i);
-        PHIReg += NumRegisters;
-      }
-    }
-  }
-}
-
-unsigned FunctionLoweringInfo::MakeReg(EVT VT) {
-  return RegInfo->createVirtualRegister(TLI.getRegClassFor(VT));
-}
-
-/// CreateRegForValue - Allocate the appropriate number of virtual registers of
-/// the correctly promoted or expanded types.  Assign these registers
-/// consecutive vreg numbers and return the first assigned number.
-///
-/// In the case that the given value has struct or array type, this function
-/// will assign registers for each member or element.
-///
-unsigned FunctionLoweringInfo::CreateRegForValue(const Value *V) {
-  SmallVector<EVT, 4> ValueVTs;
-  ComputeValueVTs(TLI, V->getType(), ValueVTs);
-
-  unsigned FirstReg = 0;
-  for (unsigned Value = 0, e = ValueVTs.size(); Value != e; ++Value) {
-    EVT ValueVT = ValueVTs[Value];
-    EVT RegisterVT = TLI.getRegisterType(V->getContext(), ValueVT);
-
-    unsigned NumRegs = TLI.getNumRegisters(V->getContext(), ValueVT);
-    for (unsigned i = 0; i != NumRegs; ++i) {
-      unsigned R = MakeReg(RegisterVT);
-      if (!FirstReg) FirstReg = R;
-    }
-  }
-  return FirstReg;
-}
-
 /// getCopyFromParts - Create a value that contains the specified legal parts
 /// combined into the value they represent.  If the parts combine to a type
 /// larger then ValueVT then AssertOp can be used to specify whether the extra
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuild.h b/lib/CodeGen/SelectionDAG/SelectionDAGBuild.h
index 10f256c153..8f9c7444b5 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuild.h
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuild.h
@@ -45,6 +45,7 @@ class FPToSIInst;
 class FPToUIInst;
 class FPTruncInst;
 class Function;
+class FunctionLoweringInfo;
 class GetElementPtrInst;
 class GCFunctionInfo;
 class ICmpInst;
@@ -79,92 +80,6 @@ class UnwindInst;
 class VAArgInst;
 class ZExtInst;
 
-//===--------------------------------------------------------------------===//
-/// FunctionLoweringInfo - This contains information that is global to a
-/// function that is used when lowering a region of the function.
-///
-class FunctionLoweringInfo {
-public:
-  TargetLowering &TLI;
-  Function *Fn;
-  MachineFunction *MF;
-  MachineRegisterInfo *RegInfo;
-
-  /// CanLowerReturn - true iff the function's return value can be lowered to
-  /// registers.
-  bool CanLowerReturn;
-
-  /// DemoteRegister - if CanLowerReturn is false, DemoteRegister is a vreg
-  /// allocated to hold a pointer to the hidden sret parameter.
-  unsigned DemoteRegister;
-
-  explicit FunctionLoweringInfo(TargetLowering &TLI);
-
-  /// set - Initialize this FunctionLoweringInfo with the given Function
-  /// and its associated MachineFunction.
-  ///
-  void set(Function &Fn, MachineFunction &MF, SelectionDAG &DAG,
-           bool EnableFastISel);
-
-  /// MBBMap - A mapping from LLVM basic blocks to their machine code entry.
-  DenseMap<const BasicBlock*, MachineBasicBlock *> MBBMap;
-
-  /// ValueMap - Since we emit code for the function a basic block at a time,
-  /// we must remember which virtual registers hold the values for
-  /// cross-basic-block values.
-  DenseMap<const Value*, unsigned> ValueMap;
-
-  /// StaticAllocaMap - Keep track of frame indices for fixed sized allocas in
-  /// the entry block.  This allows the allocas to be efficiently referenced
-  /// anywhere in the function.
-  DenseMap<const AllocaInst*, int> StaticAllocaMap;
-
-#ifndef NDEBUG
-  SmallSet<Instruction*, 8> CatchInfoLost;
-  SmallSet<Instruction*, 8> CatchInfoFound;
-#endif
-
-  unsigned MakeReg(EVT VT);
-  
-  /// isExportedInst - Return true if the specified value is an instruction
-  /// exported from its block.
-  bool isExportedInst(const Value *V) {
-    return ValueMap.count(V);
-  }
-
-  unsigned CreateRegForValue(const Value *V);
-  
-  unsigned InitializeRegForValue(const Value *V) {
-    unsigned &R = ValueMap[V];
-    assert(R == 0 && "Already initialized this value register!");
-    return R = CreateRegForValue(V);
-  }
-  
-  struct LiveOutInfo {
-    unsigned NumSignBits;
-    APInt KnownOne, KnownZero;
-    LiveOutInfo() : NumSignBits(0), KnownOne(1, 0), KnownZero(1, 0) {}
-  };
-  
-  /// LiveOutRegInfo - Information about live out vregs, indexed by their
-  /// register number offset by 'FirstVirtualRegister'.
-  std::vector<LiveOutInfo> LiveOutRegInfo;
-
-  /// clear - Clear out all the function-specific state. This returns this
-  /// FunctionLoweringInfo to an empty state, ready to be used for a
-  /// different function.
-  void clear() {
-    MBBMap.clear();
-    ValueMap.clear();
-    StaticAllocaMap.clear();
-#ifndef NDEBUG
-    CatchInfoLost.clear();
-    CatchInfoFound.clear();
-#endif
-    LiveOutRegInfo.clear();
-  }
-};
-
 //===----------------------------------------------------------------------===//
 /// SelectionDAGLowering - This is the common target-independent lowering
 /// implementation that is parameterized by a TargetLowering object.
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index 3a54a9ccd9..70bbb112c4 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -14,6 +14,7 @@
 #define DEBUG_TYPE "isel"
 #include "ScheduleDAGSDNodes.h"
 #include "SelectionDAGBuild.h"
+#include "FunctionLoweringInfo.h"
 #include "llvm/CodeGen/SelectionDAGISel.h"
 #include "llvm/Analysis/AliasAnalysis.h"
 #include "llvm/Analysis/DebugInfo.h"
@@ -331,7 +332,7 @@ bool SelectionDAGISel::runOnMachineFunction(MachineFunction &mf) {
   MachineModuleInfo *MMI = getAnalysisIfAvailable<MachineModuleInfo>();
   DwarfWriter *DW = getAnalysisIfAvailable<DwarfWriter>();
   CurDAG->init(*MF, MMI, DW);
-  FuncInfo->set(Fn, *MF, *CurDAG, EnableFastISel);
+  FuncInfo->set(Fn, *MF, EnableFastISel);
   SDL->init(GFI, *AA);
 
   for (Function::iterator I = Fn.begin(), E = Fn.end(); I != E; ++I)