Restoring authorship annotation for <[email protected]>. Commit 1 of 2.

1 files changed, 443 insertions, 443 deletions

diff --git a/contrib/libs/llvm12/lib/CodeGen/LocalStackSlotAllocation.cpp b/contrib/libs/llvm12/lib/CodeGen/LocalStackSlotAllocation.cpp
index ec6e693e8a4..82d7547ec74 100644
--- a/contrib/libs/llvm12/lib/CodeGen/LocalStackSlotAllocation.cpp
+++ b/contrib/libs/llvm12/lib/CodeGen/LocalStackSlotAllocation.cpp
@@ -1,449 +1,449 @@
-//===- LocalStackSlotAllocation.cpp - Pre-allocate locals to stack slots --===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-//
-// This pass assigns local frame indices to stack slots relative to one another
-// and allocates additional base registers to access them when the target
-// estimates they are likely to be out of range of stack pointer and frame
-// pointer relative addressing.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/ADT/SetVector.h"
-#include "llvm/ADT/SmallSet.h"
-#include "llvm/ADT/SmallVector.h"
-#include "llvm/ADT/Statistic.h"
-#include "llvm/CodeGen/MachineBasicBlock.h"
-#include "llvm/CodeGen/MachineFrameInfo.h"
-#include "llvm/CodeGen/MachineFunction.h"
-#include "llvm/CodeGen/MachineFunctionPass.h"
-#include "llvm/CodeGen/MachineInstr.h"
-#include "llvm/CodeGen/MachineOperand.h"
-#include "llvm/CodeGen/MachineRegisterInfo.h"
-#include "llvm/CodeGen/TargetFrameLowering.h"
-#include "llvm/CodeGen/TargetOpcodes.h"
-#include "llvm/CodeGen/TargetRegisterInfo.h"
-#include "llvm/CodeGen/TargetSubtargetInfo.h"
-#include "llvm/InitializePasses.h"
-#include "llvm/Pass.h"
-#include "llvm/Support/Debug.h"
-#include "llvm/Support/ErrorHandling.h"
-#include "llvm/Support/raw_ostream.h"
-#include <algorithm>
-#include <cassert>
-#include <cstdint>
-#include <tuple>
-
-using namespace llvm;
-
-#define DEBUG_TYPE "localstackalloc"
-
-STATISTIC(NumAllocations, "Number of frame indices allocated into local block");
-STATISTIC(NumBaseRegisters, "Number of virtual frame base registers allocated");
-STATISTIC(NumReplacements, "Number of frame indices references replaced");
-
-namespace {
-
-  class FrameRef {
-    MachineBasicBlock::iterator MI; // Instr referencing the frame
-    int64_t LocalOffset;            // Local offset of the frame idx referenced
-    int FrameIdx;                   // The frame index
-
-    // Order reference instruction appears in program. Used to ensure
-    // deterministic order when multiple instructions may reference the same
-    // location.
-    unsigned Order;
-
-  public:
-    FrameRef(MachineInstr *I, int64_t Offset, int Idx, unsigned Ord) :
-      MI(I), LocalOffset(Offset), FrameIdx(Idx), Order(Ord) {}
-
-    bool operator<(const FrameRef &RHS) const {
-      return std::tie(LocalOffset, FrameIdx, Order) <
-             std::tie(RHS.LocalOffset, RHS.FrameIdx, RHS.Order);
-    }
-
-    MachineBasicBlock::iterator getMachineInstr() const { return MI; }
-    int64_t getLocalOffset() const { return LocalOffset; }
-    int getFrameIndex() const { return FrameIdx; }
-  };
-
-  class LocalStackSlotPass: public MachineFunctionPass {
-    SmallVector<int64_t, 16> LocalOffsets;
-
-    /// StackObjSet - A set of stack object indexes
-    using StackObjSet = SmallSetVector<int, 8>;
-
-    void AdjustStackOffset(MachineFrameInfo &MFI, int FrameIdx, int64_t &Offset,
-                           bool StackGrowsDown, Align &MaxAlign);
-    void AssignProtectedObjSet(const StackObjSet &UnassignedObjs,
-                               SmallSet<int, 16> &ProtectedObjs,
-                               MachineFrameInfo &MFI, bool StackGrowsDown,
-                               int64_t &Offset, Align &MaxAlign);
-    void calculateFrameObjectOffsets(MachineFunction &Fn);
-    bool insertFrameReferenceRegisters(MachineFunction &Fn);
-
-  public:
-    static char ID; // Pass identification, replacement for typeid
-
-    explicit LocalStackSlotPass() : MachineFunctionPass(ID) {
-      initializeLocalStackSlotPassPass(*PassRegistry::getPassRegistry());
-    }
-
-    bool runOnMachineFunction(MachineFunction &MF) override;
-
-    void getAnalysisUsage(AnalysisUsage &AU) const override {
-      AU.setPreservesCFG();
-      MachineFunctionPass::getAnalysisUsage(AU);
-    }
-  };
-
-} // end anonymous namespace
-
-char LocalStackSlotPass::ID = 0;
-
-char &llvm::LocalStackSlotAllocationID = LocalStackSlotPass::ID;
-INITIALIZE_PASS(LocalStackSlotPass, DEBUG_TYPE,
-                "Local Stack Slot Allocation", false, false)
-
-bool LocalStackSlotPass::runOnMachineFunction(MachineFunction &MF) {
-  MachineFrameInfo &MFI = MF.getFrameInfo();
-  const TargetRegisterInfo *TRI = MF.getSubtarget().getRegisterInfo();
-  unsigned LocalObjectCount = MFI.getObjectIndexEnd();
-
-  // If the target doesn't want/need this pass, or if there are no locals
-  // to consider, early exit.
+//===- LocalStackSlotAllocation.cpp - Pre-allocate locals to stack slots --===// 
+// 
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 
+// See https://llvm.org/LICENSE.txt for license information. 
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 
+// 
+//===----------------------------------------------------------------------===// 
+// 
+// This pass assigns local frame indices to stack slots relative to one another 
+// and allocates additional base registers to access them when the target 
+// estimates they are likely to be out of range of stack pointer and frame 
+// pointer relative addressing. 
+// 
+//===----------------------------------------------------------------------===// 
+ 
+#include "llvm/ADT/SetVector.h" 
+#include "llvm/ADT/SmallSet.h" 
+#include "llvm/ADT/SmallVector.h" 
+#include "llvm/ADT/Statistic.h" 
+#include "llvm/CodeGen/MachineBasicBlock.h" 
+#include "llvm/CodeGen/MachineFrameInfo.h" 
+#include "llvm/CodeGen/MachineFunction.h" 
+#include "llvm/CodeGen/MachineFunctionPass.h" 
+#include "llvm/CodeGen/MachineInstr.h" 
+#include "llvm/CodeGen/MachineOperand.h" 
+#include "llvm/CodeGen/MachineRegisterInfo.h" 
+#include "llvm/CodeGen/TargetFrameLowering.h" 
+#include "llvm/CodeGen/TargetOpcodes.h" 
+#include "llvm/CodeGen/TargetRegisterInfo.h" 
+#include "llvm/CodeGen/TargetSubtargetInfo.h" 
+#include "llvm/InitializePasses.h" 
+#include "llvm/Pass.h" 
+#include "llvm/Support/Debug.h" 
+#include "llvm/Support/ErrorHandling.h" 
+#include "llvm/Support/raw_ostream.h" 
+#include <algorithm> 
+#include <cassert> 
+#include <cstdint> 
+#include <tuple> 
+ 
+using namespace llvm; 
+ 
+#define DEBUG_TYPE "localstackalloc" 
+ 
+STATISTIC(NumAllocations, "Number of frame indices allocated into local block"); 
+STATISTIC(NumBaseRegisters, "Number of virtual frame base registers allocated"); 
+STATISTIC(NumReplacements, "Number of frame indices references replaced"); 
+ 
+namespace { 
+ 
+  class FrameRef { 
+    MachineBasicBlock::iterator MI; // Instr referencing the frame 
+    int64_t LocalOffset;            // Local offset of the frame idx referenced 
+    int FrameIdx;                   // The frame index 
+ 
+    // Order reference instruction appears in program. Used to ensure 
+    // deterministic order when multiple instructions may reference the same 
+    // location. 
+    unsigned Order; 
+ 
+  public: 
+    FrameRef(MachineInstr *I, int64_t Offset, int Idx, unsigned Ord) : 
+      MI(I), LocalOffset(Offset), FrameIdx(Idx), Order(Ord) {} 
+ 
+    bool operator<(const FrameRef &RHS) const { 
+      return std::tie(LocalOffset, FrameIdx, Order) < 
+             std::tie(RHS.LocalOffset, RHS.FrameIdx, RHS.Order); 
+    } 
+ 
+    MachineBasicBlock::iterator getMachineInstr() const { return MI; } 
+    int64_t getLocalOffset() const { return LocalOffset; } 
+    int getFrameIndex() const { return FrameIdx; } 
+  }; 
+ 
+  class LocalStackSlotPass: public MachineFunctionPass { 
+    SmallVector<int64_t, 16> LocalOffsets; 
+ 
+    /// StackObjSet - A set of stack object indexes 
+    using StackObjSet = SmallSetVector<int, 8>; 
+ 
+    void AdjustStackOffset(MachineFrameInfo &MFI, int FrameIdx, int64_t &Offset, 
+                           bool StackGrowsDown, Align &MaxAlign); 
+    void AssignProtectedObjSet(const StackObjSet &UnassignedObjs, 
+                               SmallSet<int, 16> &ProtectedObjs, 
+                               MachineFrameInfo &MFI, bool StackGrowsDown, 
+                               int64_t &Offset, Align &MaxAlign); 
+    void calculateFrameObjectOffsets(MachineFunction &Fn); 
+    bool insertFrameReferenceRegisters(MachineFunction &Fn); 
+ 
+  public: 
+    static char ID; // Pass identification, replacement for typeid 
+ 
+    explicit LocalStackSlotPass() : MachineFunctionPass(ID) { 
+      initializeLocalStackSlotPassPass(*PassRegistry::getPassRegistry()); 
+    } 
+ 
+    bool runOnMachineFunction(MachineFunction &MF) override; 
+ 
+    void getAnalysisUsage(AnalysisUsage &AU) const override { 
+      AU.setPreservesCFG(); 
+      MachineFunctionPass::getAnalysisUsage(AU); 
+    } 
+  }; 
+ 
+} // end anonymous namespace 
+ 
+char LocalStackSlotPass::ID = 0; 
+ 
+char &llvm::LocalStackSlotAllocationID = LocalStackSlotPass::ID; 
+INITIALIZE_PASS(LocalStackSlotPass, DEBUG_TYPE, 
+                "Local Stack Slot Allocation", false, false) 
+ 
+bool LocalStackSlotPass::runOnMachineFunction(MachineFunction &MF) { 
+  MachineFrameInfo &MFI = MF.getFrameInfo(); 
+  const TargetRegisterInfo *TRI = MF.getSubtarget().getRegisterInfo(); 
+  unsigned LocalObjectCount = MFI.getObjectIndexEnd(); 
+ 
+  // If the target doesn't want/need this pass, or if there are no locals 
+  // to consider, early exit. 
   if (LocalObjectCount == 0 || !TRI->requiresVirtualBaseRegisters(MF))
-    return true;
-
-  // Make sure we have enough space to store the local offsets.
-  LocalOffsets.resize(MFI.getObjectIndexEnd());
-
-  // Lay out the local blob.
-  calculateFrameObjectOffsets(MF);
-
-  // Insert virtual base registers to resolve frame index references.
-  bool UsedBaseRegs = insertFrameReferenceRegisters(MF);
-
-  // Tell MFI whether any base registers were allocated. PEI will only
-  // want to use the local block allocations from this pass if there were any.
-  // Otherwise, PEI can do a bit better job of getting the alignment right
-  // without a hole at the start since it knows the alignment of the stack
-  // at the start of local allocation, and this pass doesn't.
-  MFI.setUseLocalStackAllocationBlock(UsedBaseRegs);
-
-  return true;
-}
-
-/// AdjustStackOffset - Helper function used to adjust the stack frame offset.
-void LocalStackSlotPass::AdjustStackOffset(MachineFrameInfo &MFI, int FrameIdx,
-                                           int64_t &Offset, bool StackGrowsDown,
-                                           Align &MaxAlign) {
-  // If the stack grows down, add the object size to find the lowest address.
-  if (StackGrowsDown)
-    Offset += MFI.getObjectSize(FrameIdx);
-
-  Align Alignment = MFI.getObjectAlign(FrameIdx);
-
-  // If the alignment of this object is greater than that of the stack, then
-  // increase the stack alignment to match.
-  MaxAlign = std::max(MaxAlign, Alignment);
-
-  // Adjust to alignment boundary.
-  Offset = alignTo(Offset, Alignment);
-
-  int64_t LocalOffset = StackGrowsDown ? -Offset : Offset;
-  LLVM_DEBUG(dbgs() << "Allocate FI(" << FrameIdx << ") to local offset "
-                    << LocalOffset << "\n");
-  // Keep the offset available for base register allocation
-  LocalOffsets[FrameIdx] = LocalOffset;
-  // And tell MFI about it for PEI to use later
-  MFI.mapLocalFrameObject(FrameIdx, LocalOffset);
-
-  if (!StackGrowsDown)
-    Offset += MFI.getObjectSize(FrameIdx);
-
-  ++NumAllocations;
-}
-
-/// AssignProtectedObjSet - Helper function to assign large stack objects (i.e.,
-/// those required to be close to the Stack Protector) to stack offsets.
-void LocalStackSlotPass::AssignProtectedObjSet(
-    const StackObjSet &UnassignedObjs, SmallSet<int, 16> &ProtectedObjs,
-    MachineFrameInfo &MFI, bool StackGrowsDown, int64_t &Offset,
-    Align &MaxAlign) {
-  for (StackObjSet::const_iterator I = UnassignedObjs.begin(),
-        E = UnassignedObjs.end(); I != E; ++I) {
-    int i = *I;
-    AdjustStackOffset(MFI, i, Offset, StackGrowsDown, MaxAlign);
-    ProtectedObjs.insert(i);
-  }
-}
-
-/// calculateFrameObjectOffsets - Calculate actual frame offsets for all of the
-/// abstract stack objects.
-void LocalStackSlotPass::calculateFrameObjectOffsets(MachineFunction &Fn) {
-  // Loop over all of the stack objects, assigning sequential addresses...
-  MachineFrameInfo &MFI = Fn.getFrameInfo();
-  const TargetFrameLowering &TFI = *Fn.getSubtarget().getFrameLowering();
-  bool StackGrowsDown =
-    TFI.getStackGrowthDirection() == TargetFrameLowering::StackGrowsDown;
-  int64_t Offset = 0;
-  Align MaxAlign;
-
-  // Make sure that the stack protector comes before the local variables on the
-  // stack.
-  SmallSet<int, 16> ProtectedObjs;
-  if (MFI.hasStackProtectorIndex()) {
-    int StackProtectorFI = MFI.getStackProtectorIndex();
-
-    // We need to make sure we didn't pre-allocate the stack protector when
-    // doing this.
-    // If we already have a stack protector, this will re-assign it to a slot
-    // that is **not** covering the protected objects.
-    assert(!MFI.isObjectPreAllocated(StackProtectorFI) &&
-           "Stack protector pre-allocated in LocalStackSlotAllocation");
-
-    StackObjSet LargeArrayObjs;
-    StackObjSet SmallArrayObjs;
-    StackObjSet AddrOfObjs;
-
-    AdjustStackOffset(MFI, StackProtectorFI, Offset, StackGrowsDown, MaxAlign);
-
-    // Assign large stack objects first.
-    for (unsigned i = 0, e = MFI.getObjectIndexEnd(); i != e; ++i) {
-      if (MFI.isDeadObjectIndex(i))
-        continue;
-      if (StackProtectorFI == (int)i)
-        continue;
-      if (!TFI.isStackIdSafeForLocalArea(MFI.getStackID(i)))
-        continue;
-
-      switch (MFI.getObjectSSPLayout(i)) {
-      case MachineFrameInfo::SSPLK_None:
-        continue;
-      case MachineFrameInfo::SSPLK_SmallArray:
-        SmallArrayObjs.insert(i);
-        continue;
-      case MachineFrameInfo::SSPLK_AddrOf:
-        AddrOfObjs.insert(i);
-        continue;
-      case MachineFrameInfo::SSPLK_LargeArray:
-        LargeArrayObjs.insert(i);
-        continue;
-      }
-      llvm_unreachable("Unexpected SSPLayoutKind.");
-    }
-
-    AssignProtectedObjSet(LargeArrayObjs, ProtectedObjs, MFI, StackGrowsDown,
-                          Offset, MaxAlign);
-    AssignProtectedObjSet(SmallArrayObjs, ProtectedObjs, MFI, StackGrowsDown,
-                          Offset, MaxAlign);
-    AssignProtectedObjSet(AddrOfObjs, ProtectedObjs, MFI, StackGrowsDown,
-                          Offset, MaxAlign);
-  }
-
-  // Then assign frame offsets to stack objects that are not used to spill
-  // callee saved registers.
-  for (unsigned i = 0, e = MFI.getObjectIndexEnd(); i != e; ++i) {
-    if (MFI.isDeadObjectIndex(i))
-      continue;
-    if (MFI.getStackProtectorIndex() == (int)i)
-      continue;
-    if (ProtectedObjs.count(i))
-      continue;
-    if (!TFI.isStackIdSafeForLocalArea(MFI.getStackID(i)))
-      continue;
-
-    AdjustStackOffset(MFI, i, Offset, StackGrowsDown, MaxAlign);
-  }
-
-  // Remember how big this blob of stack space is
-  MFI.setLocalFrameSize(Offset);
-  MFI.setLocalFrameMaxAlign(MaxAlign);
-}
-
-static inline bool
-lookupCandidateBaseReg(unsigned BaseReg,
-                       int64_t BaseOffset,
-                       int64_t FrameSizeAdjust,
-                       int64_t LocalFrameOffset,
-                       const MachineInstr &MI,
-                       const TargetRegisterInfo *TRI) {
-  // Check if the relative offset from the where the base register references
-  // to the target address is in range for the instruction.
-  int64_t Offset = FrameSizeAdjust + LocalFrameOffset - BaseOffset;
-  return TRI->isFrameOffsetLegal(&MI, BaseReg, Offset);
-}
-
-bool LocalStackSlotPass::insertFrameReferenceRegisters(MachineFunction &Fn) {
-  // Scan the function's instructions looking for frame index references.
-  // For each, ask the target if it wants a virtual base register for it
-  // based on what we can tell it about where the local will end up in the
-  // stack frame. If it wants one, re-use a suitable one we've previously
-  // allocated, or if there isn't one that fits the bill, allocate a new one
-  // and ask the target to create a defining instruction for it.
-  bool UsedBaseReg = false;
-
-  MachineFrameInfo &MFI = Fn.getFrameInfo();
-  const TargetRegisterInfo *TRI = Fn.getSubtarget().getRegisterInfo();
-  const TargetFrameLowering &TFI = *Fn.getSubtarget().getFrameLowering();
-  bool StackGrowsDown =
-    TFI.getStackGrowthDirection() == TargetFrameLowering::StackGrowsDown;
-
-  // Collect all of the instructions in the block that reference
-  // a frame index. Also store the frame index referenced to ease later
-  // lookup. (For any insn that has more than one FI reference, we arbitrarily
-  // choose the first one).
-  SmallVector<FrameRef, 64> FrameReferenceInsns;
-
-  unsigned Order = 0;
-
-  for (MachineBasicBlock &BB : Fn) {
-    for (MachineInstr &MI : BB) {
-      // Debug value, stackmap and patchpoint instructions can't be out of
-      // range, so they don't need any updates.
-      if (MI.isDebugInstr() || MI.getOpcode() == TargetOpcode::STATEPOINT ||
-          MI.getOpcode() == TargetOpcode::STACKMAP ||
-          MI.getOpcode() == TargetOpcode::PATCHPOINT)
-        continue;
-
-      // For now, allocate the base register(s) within the basic block
-      // where they're used, and don't try to keep them around outside
-      // of that. It may be beneficial to try sharing them more broadly
-      // than that, but the increased register pressure makes that a
-      // tricky thing to balance. Investigate if re-materializing these
-      // becomes an issue.
-      for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) {
-        // Consider replacing all frame index operands that reference
-        // an object allocated in the local block.
-        if (MI.getOperand(i).isFI()) {
-          // Don't try this with values not in the local block.
-          if (!MFI.isObjectPreAllocated(MI.getOperand(i).getIndex()))
-            break;
-          int Idx = MI.getOperand(i).getIndex();
-          int64_t LocalOffset = LocalOffsets[Idx];
-          if (!TRI->needsFrameBaseReg(&MI, LocalOffset))
-            break;
-          FrameReferenceInsns.push_back(FrameRef(&MI, LocalOffset, Idx, Order++));
-          break;
-        }
-      }
-    }
-  }
-
-  // Sort the frame references by local offset.
-  // Use frame index as a tie-breaker in case MI's have the same offset.
-  llvm::sort(FrameReferenceInsns);
-
-  MachineBasicBlock *Entry = &Fn.front();
-
-  unsigned BaseReg = 0;
-  int64_t BaseOffset = 0;
-
-  // Loop through the frame references and allocate for them as necessary.
-  for (int ref = 0, e = FrameReferenceInsns.size(); ref < e ; ++ref) {
-    FrameRef &FR = FrameReferenceInsns[ref];
-    MachineInstr &MI = *FR.getMachineInstr();
-    int64_t LocalOffset = FR.getLocalOffset();
-    int FrameIdx = FR.getFrameIndex();
-    assert(MFI.isObjectPreAllocated(FrameIdx) &&
-           "Only pre-allocated locals expected!");
-
-    // We need to keep the references to the stack protector slot through frame
-    // index operands so that it gets resolved by PEI rather than this pass.
-    // This avoids accesses to the stack protector though virtual base
-    // registers, and forces PEI to address it using fp/sp/bp.
-    if (MFI.hasStackProtectorIndex() &&
-        FrameIdx == MFI.getStackProtectorIndex())
-      continue;
-
-    LLVM_DEBUG(dbgs() << "Considering: " << MI);
-
-    unsigned idx = 0;
-    for (unsigned f = MI.getNumOperands(); idx != f; ++idx) {
-      if (!MI.getOperand(idx).isFI())
-        continue;
-
-      if (FrameIdx == MI.getOperand(idx).getIndex())
-        break;
-    }
-
-    assert(idx < MI.getNumOperands() && "Cannot find FI operand");
-
-    int64_t Offset = 0;
-    int64_t FrameSizeAdjust = StackGrowsDown ? MFI.getLocalFrameSize() : 0;
-
-    LLVM_DEBUG(dbgs() << "  Replacing FI in: " << MI);
-
-    // If we have a suitable base register available, use it; otherwise
-    // create a new one. Note that any offset encoded in the
-    // instruction itself will be taken into account by the target,
-    // so we don't have to adjust for it here when reusing a base
-    // register.
-    if (UsedBaseReg &&
-        lookupCandidateBaseReg(BaseReg, BaseOffset, FrameSizeAdjust,
-                               LocalOffset, MI, TRI)) {
-      LLVM_DEBUG(dbgs() << "  Reusing base register " << BaseReg << "\n");
-      // We found a register to reuse.
-      Offset = FrameSizeAdjust + LocalOffset - BaseOffset;
-    } else {
-      // No previously defined register was in range, so create a new one.
-      int64_t InstrOffset = TRI->getFrameIndexInstrOffset(&MI, idx);
-
-      int64_t PrevBaseOffset = BaseOffset;
-      BaseOffset = FrameSizeAdjust + LocalOffset + InstrOffset;
-
-      // We'd like to avoid creating single-use virtual base registers.
-      // Because the FrameRefs are in sorted order, and we've already
-      // processed all FrameRefs before this one, just check whether or not
-      // the next FrameRef will be able to reuse this new register. If not,
-      // then don't bother creating it.
-      if (ref + 1 >= e ||
-          !lookupCandidateBaseReg(
-              BaseReg, BaseOffset, FrameSizeAdjust,
-              FrameReferenceInsns[ref + 1].getLocalOffset(),
-              *FrameReferenceInsns[ref + 1].getMachineInstr(), TRI)) {
-        BaseOffset = PrevBaseOffset;
-        continue;
-      }
-
-      const MachineFunction *MF = MI.getMF();
-      const TargetRegisterClass *RC = TRI->getPointerRegClass(*MF);
-      BaseReg = Fn.getRegInfo().createVirtualRegister(RC);
-
+    return true; 
+ 
+  // Make sure we have enough space to store the local offsets. 
+  LocalOffsets.resize(MFI.getObjectIndexEnd()); 
+ 
+  // Lay out the local blob. 
+  calculateFrameObjectOffsets(MF); 
+ 
+  // Insert virtual base registers to resolve frame index references. 
+  bool UsedBaseRegs = insertFrameReferenceRegisters(MF); 
+ 
+  // Tell MFI whether any base registers were allocated. PEI will only 
+  // want to use the local block allocations from this pass if there were any. 
+  // Otherwise, PEI can do a bit better job of getting the alignment right 
+  // without a hole at the start since it knows the alignment of the stack 
+  // at the start of local allocation, and this pass doesn't. 
+  MFI.setUseLocalStackAllocationBlock(UsedBaseRegs); 
+ 
+  return true; 
+} 
+ 
+/// AdjustStackOffset - Helper function used to adjust the stack frame offset. 
+void LocalStackSlotPass::AdjustStackOffset(MachineFrameInfo &MFI, int FrameIdx, 
+                                           int64_t &Offset, bool StackGrowsDown, 
+                                           Align &MaxAlign) { 
+  // If the stack grows down, add the object size to find the lowest address. 
+  if (StackGrowsDown) 
+    Offset += MFI.getObjectSize(FrameIdx); 
+ 
+  Align Alignment = MFI.getObjectAlign(FrameIdx); 
+ 
+  // If the alignment of this object is greater than that of the stack, then 
+  // increase the stack alignment to match. 
+  MaxAlign = std::max(MaxAlign, Alignment); 
+ 
+  // Adjust to alignment boundary. 
+  Offset = alignTo(Offset, Alignment); 
+ 
+  int64_t LocalOffset = StackGrowsDown ? -Offset : Offset; 
+  LLVM_DEBUG(dbgs() << "Allocate FI(" << FrameIdx << ") to local offset " 
+                    << LocalOffset << "\n"); 
+  // Keep the offset available for base register allocation 
+  LocalOffsets[FrameIdx] = LocalOffset; 
+  // And tell MFI about it for PEI to use later 
+  MFI.mapLocalFrameObject(FrameIdx, LocalOffset); 
+ 
+  if (!StackGrowsDown) 
+    Offset += MFI.getObjectSize(FrameIdx); 
+ 
+  ++NumAllocations; 
+} 
+ 
+/// AssignProtectedObjSet - Helper function to assign large stack objects (i.e., 
+/// those required to be close to the Stack Protector) to stack offsets. 
+void LocalStackSlotPass::AssignProtectedObjSet( 
+    const StackObjSet &UnassignedObjs, SmallSet<int, 16> &ProtectedObjs, 
+    MachineFrameInfo &MFI, bool StackGrowsDown, int64_t &Offset, 
+    Align &MaxAlign) { 
+  for (StackObjSet::const_iterator I = UnassignedObjs.begin(), 
+        E = UnassignedObjs.end(); I != E; ++I) { 
+    int i = *I; 
+    AdjustStackOffset(MFI, i, Offset, StackGrowsDown, MaxAlign); 
+    ProtectedObjs.insert(i); 
+  } 
+} 
+ 
+/// calculateFrameObjectOffsets - Calculate actual frame offsets for all of the 
+/// abstract stack objects. 
+void LocalStackSlotPass::calculateFrameObjectOffsets(MachineFunction &Fn) { 
+  // Loop over all of the stack objects, assigning sequential addresses... 
+  MachineFrameInfo &MFI = Fn.getFrameInfo(); 
+  const TargetFrameLowering &TFI = *Fn.getSubtarget().getFrameLowering(); 
+  bool StackGrowsDown = 
+    TFI.getStackGrowthDirection() == TargetFrameLowering::StackGrowsDown; 
+  int64_t Offset = 0; 
+  Align MaxAlign; 
+ 
+  // Make sure that the stack protector comes before the local variables on the 
+  // stack. 
+  SmallSet<int, 16> ProtectedObjs; 
+  if (MFI.hasStackProtectorIndex()) { 
+    int StackProtectorFI = MFI.getStackProtectorIndex(); 
+ 
+    // We need to make sure we didn't pre-allocate the stack protector when 
+    // doing this. 
+    // If we already have a stack protector, this will re-assign it to a slot 
+    // that is **not** covering the protected objects. 
+    assert(!MFI.isObjectPreAllocated(StackProtectorFI) && 
+           "Stack protector pre-allocated in LocalStackSlotAllocation"); 
+ 
+    StackObjSet LargeArrayObjs; 
+    StackObjSet SmallArrayObjs; 
+    StackObjSet AddrOfObjs; 
+ 
+    AdjustStackOffset(MFI, StackProtectorFI, Offset, StackGrowsDown, MaxAlign); 
+ 
+    // Assign large stack objects first. 
+    for (unsigned i = 0, e = MFI.getObjectIndexEnd(); i != e; ++i) { 
+      if (MFI.isDeadObjectIndex(i)) 
+        continue; 
+      if (StackProtectorFI == (int)i) 
+        continue; 
+      if (!TFI.isStackIdSafeForLocalArea(MFI.getStackID(i))) 
+        continue; 
+ 
+      switch (MFI.getObjectSSPLayout(i)) { 
+      case MachineFrameInfo::SSPLK_None: 
+        continue; 
+      case MachineFrameInfo::SSPLK_SmallArray: 
+        SmallArrayObjs.insert(i); 
+        continue; 
+      case MachineFrameInfo::SSPLK_AddrOf: 
+        AddrOfObjs.insert(i); 
+        continue; 
+      case MachineFrameInfo::SSPLK_LargeArray: 
+        LargeArrayObjs.insert(i); 
+        continue; 
+      } 
+      llvm_unreachable("Unexpected SSPLayoutKind."); 
+    } 
+ 
+    AssignProtectedObjSet(LargeArrayObjs, ProtectedObjs, MFI, StackGrowsDown, 
+                          Offset, MaxAlign); 
+    AssignProtectedObjSet(SmallArrayObjs, ProtectedObjs, MFI, StackGrowsDown, 
+                          Offset, MaxAlign); 
+    AssignProtectedObjSet(AddrOfObjs, ProtectedObjs, MFI, StackGrowsDown, 
+                          Offset, MaxAlign); 
+  } 
+ 
+  // Then assign frame offsets to stack objects that are not used to spill 
+  // callee saved registers. 
+  for (unsigned i = 0, e = MFI.getObjectIndexEnd(); i != e; ++i) { 
+    if (MFI.isDeadObjectIndex(i)) 
+      continue; 
+    if (MFI.getStackProtectorIndex() == (int)i) 
+      continue; 
+    if (ProtectedObjs.count(i)) 
+      continue; 
+    if (!TFI.isStackIdSafeForLocalArea(MFI.getStackID(i))) 
+      continue; 
+ 
+    AdjustStackOffset(MFI, i, Offset, StackGrowsDown, MaxAlign); 
+  } 
+ 
+  // Remember how big this blob of stack space is 
+  MFI.setLocalFrameSize(Offset); 
+  MFI.setLocalFrameMaxAlign(MaxAlign); 
+} 
+ 
+static inline bool 
+lookupCandidateBaseReg(unsigned BaseReg, 
+                       int64_t BaseOffset, 
+                       int64_t FrameSizeAdjust, 
+                       int64_t LocalFrameOffset, 
+                       const MachineInstr &MI, 
+                       const TargetRegisterInfo *TRI) { 
+  // Check if the relative offset from the where the base register references 
+  // to the target address is in range for the instruction. 
+  int64_t Offset = FrameSizeAdjust + LocalFrameOffset - BaseOffset; 
+  return TRI->isFrameOffsetLegal(&MI, BaseReg, Offset); 
+} 
+ 
+bool LocalStackSlotPass::insertFrameReferenceRegisters(MachineFunction &Fn) { 
+  // Scan the function's instructions looking for frame index references. 
+  // For each, ask the target if it wants a virtual base register for it 
+  // based on what we can tell it about where the local will end up in the 
+  // stack frame. If it wants one, re-use a suitable one we've previously 
+  // allocated, or if there isn't one that fits the bill, allocate a new one 
+  // and ask the target to create a defining instruction for it. 
+  bool UsedBaseReg = false; 
+ 
+  MachineFrameInfo &MFI = Fn.getFrameInfo(); 
+  const TargetRegisterInfo *TRI = Fn.getSubtarget().getRegisterInfo(); 
+  const TargetFrameLowering &TFI = *Fn.getSubtarget().getFrameLowering(); 
+  bool StackGrowsDown = 
+    TFI.getStackGrowthDirection() == TargetFrameLowering::StackGrowsDown; 
+ 
+  // Collect all of the instructions in the block that reference 
+  // a frame index. Also store the frame index referenced to ease later 
+  // lookup. (For any insn that has more than one FI reference, we arbitrarily 
+  // choose the first one). 
+  SmallVector<FrameRef, 64> FrameReferenceInsns; 
+ 
+  unsigned Order = 0; 
+ 
+  for (MachineBasicBlock &BB : Fn) { 
+    for (MachineInstr &MI : BB) { 
+      // Debug value, stackmap and patchpoint instructions can't be out of 
+      // range, so they don't need any updates. 
+      if (MI.isDebugInstr() || MI.getOpcode() == TargetOpcode::STATEPOINT || 
+          MI.getOpcode() == TargetOpcode::STACKMAP || 
+          MI.getOpcode() == TargetOpcode::PATCHPOINT) 
+        continue; 
+ 
+      // For now, allocate the base register(s) within the basic block 
+      // where they're used, and don't try to keep them around outside 
+      // of that. It may be beneficial to try sharing them more broadly 
+      // than that, but the increased register pressure makes that a 
+      // tricky thing to balance. Investigate if re-materializing these 
+      // becomes an issue. 
+      for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) { 
+        // Consider replacing all frame index operands that reference 
+        // an object allocated in the local block. 
+        if (MI.getOperand(i).isFI()) { 
+          // Don't try this with values not in the local block. 
+          if (!MFI.isObjectPreAllocated(MI.getOperand(i).getIndex())) 
+            break; 
+          int Idx = MI.getOperand(i).getIndex(); 
+          int64_t LocalOffset = LocalOffsets[Idx]; 
+          if (!TRI->needsFrameBaseReg(&MI, LocalOffset)) 
+            break; 
+          FrameReferenceInsns.push_back(FrameRef(&MI, LocalOffset, Idx, Order++)); 
+          break; 
+        } 
+      } 
+    } 
+  } 
+ 
+  // Sort the frame references by local offset. 
+  // Use frame index as a tie-breaker in case MI's have the same offset. 
+  llvm::sort(FrameReferenceInsns); 
+ 
+  MachineBasicBlock *Entry = &Fn.front(); 
+ 
+  unsigned BaseReg = 0; 
+  int64_t BaseOffset = 0; 
+ 
+  // Loop through the frame references and allocate for them as necessary. 
+  for (int ref = 0, e = FrameReferenceInsns.size(); ref < e ; ++ref) { 
+    FrameRef &FR = FrameReferenceInsns[ref]; 
+    MachineInstr &MI = *FR.getMachineInstr(); 
+    int64_t LocalOffset = FR.getLocalOffset(); 
+    int FrameIdx = FR.getFrameIndex(); 
+    assert(MFI.isObjectPreAllocated(FrameIdx) && 
+           "Only pre-allocated locals expected!"); 
+ 
+    // We need to keep the references to the stack protector slot through frame 
+    // index operands so that it gets resolved by PEI rather than this pass. 
+    // This avoids accesses to the stack protector though virtual base 
+    // registers, and forces PEI to address it using fp/sp/bp. 
+    if (MFI.hasStackProtectorIndex() && 
+        FrameIdx == MFI.getStackProtectorIndex()) 
+      continue; 
+ 
+    LLVM_DEBUG(dbgs() << "Considering: " << MI); 
+ 
+    unsigned idx = 0; 
+    for (unsigned f = MI.getNumOperands(); idx != f; ++idx) { 
+      if (!MI.getOperand(idx).isFI()) 
+        continue; 
+ 
+      if (FrameIdx == MI.getOperand(idx).getIndex()) 
+        break; 
+    } 
+ 
+    assert(idx < MI.getNumOperands() && "Cannot find FI operand"); 
+ 
+    int64_t Offset = 0; 
+    int64_t FrameSizeAdjust = StackGrowsDown ? MFI.getLocalFrameSize() : 0; 
+ 
+    LLVM_DEBUG(dbgs() << "  Replacing FI in: " << MI); 
+ 
+    // If we have a suitable base register available, use it; otherwise 
+    // create a new one. Note that any offset encoded in the 
+    // instruction itself will be taken into account by the target, 
+    // so we don't have to adjust for it here when reusing a base 
+    // register. 
+    if (UsedBaseReg && 
+        lookupCandidateBaseReg(BaseReg, BaseOffset, FrameSizeAdjust, 
+                               LocalOffset, MI, TRI)) { 
+      LLVM_DEBUG(dbgs() << "  Reusing base register " << BaseReg << "\n"); 
+      // We found a register to reuse. 
+      Offset = FrameSizeAdjust + LocalOffset - BaseOffset; 
+    } else { 
+      // No previously defined register was in range, so create a new one. 
+      int64_t InstrOffset = TRI->getFrameIndexInstrOffset(&MI, idx); 
+ 
+      int64_t PrevBaseOffset = BaseOffset; 
+      BaseOffset = FrameSizeAdjust + LocalOffset + InstrOffset; 
+ 
+      // We'd like to avoid creating single-use virtual base registers. 
+      // Because the FrameRefs are in sorted order, and we've already 
+      // processed all FrameRefs before this one, just check whether or not 
+      // the next FrameRef will be able to reuse this new register. If not, 
+      // then don't bother creating it. 
+      if (ref + 1 >= e || 
+          !lookupCandidateBaseReg( 
+              BaseReg, BaseOffset, FrameSizeAdjust, 
+              FrameReferenceInsns[ref + 1].getLocalOffset(), 
+              *FrameReferenceInsns[ref + 1].getMachineInstr(), TRI)) { 
+        BaseOffset = PrevBaseOffset; 
+        continue; 
+      } 
+ 
+      const MachineFunction *MF = MI.getMF(); 
+      const TargetRegisterClass *RC = TRI->getPointerRegClass(*MF); 
+      BaseReg = Fn.getRegInfo().createVirtualRegister(RC); 
+ 
       LLVM_DEBUG(dbgs() << "  Materializing base register"
-                        << " at frame local offset "
+                        << " at frame local offset " 
                         << LocalOffset + InstrOffset);
-
-      // Tell the target to insert the instruction to initialize
-      // the base register.
-      //            MachineBasicBlock::iterator InsertionPt = Entry->begin();
+ 
+      // Tell the target to insert the instruction to initialize 
+      // the base register. 
+      //            MachineBasicBlock::iterator InsertionPt = Entry->begin(); 
       BaseReg = TRI->materializeFrameBaseRegister(Entry, FrameIdx, InstrOffset);
-
+ 
       LLVM_DEBUG(dbgs() << " into " << printReg(BaseReg, TRI) << '\n');
 
-      // The base register already includes any offset specified
-      // by the instruction, so account for that so it doesn't get
-      // applied twice.
-      Offset = -InstrOffset;
-
-      ++NumBaseRegisters;
-      UsedBaseReg = true;
-    }
-    assert(BaseReg != 0 && "Unable to allocate virtual base register!");
-
-    // Modify the instruction to use the new base register rather
-    // than the frame index operand.
-    TRI->resolveFrameIndex(MI, BaseReg, Offset);
-    LLVM_DEBUG(dbgs() << "Resolved: " << MI);
-
-    ++NumReplacements;
-  }
-
-  return UsedBaseReg;
-}
+      // The base register already includes any offset specified 
+      // by the instruction, so account for that so it doesn't get 
+      // applied twice. 
+      Offset = -InstrOffset; 
+ 
+      ++NumBaseRegisters; 
+      UsedBaseReg = true; 
+    } 
+    assert(BaseReg != 0 && "Unable to allocate virtual base register!"); 
+ 
+    // Modify the instruction to use the new base register rather 
+    // than the frame index operand. 
+    TRI->resolveFrameIndex(MI, BaseReg, Offset); 
+    LLVM_DEBUG(dbgs() << "Resolved: " << MI); 
+ 
+    ++NumReplacements; 
+  } 
+ 
+  return UsedBaseReg; 
+}