Update clang, llvm, lld, lldb, compiler-rt and libc++ to 4.0.0 release:

MFC r309142 (by emaste):

Add WITH_LLD_AS_LD build knob

If set it installs LLD as /usr/bin/ld.  LLD (as of version 3.9) is not
capable of linking the world and kernel, but can self-host and link many
substantial applications. GNU ld continues to be used for the world and
kernel build, regardless of how this knob is set.

It is on by default for arm64, and off for all other CPU architectures.

Sponsored by:	The FreeBSD Foundation

MFC r310840:

Reapply 310775, now it also builds correctly if lldb is disabled:

Move llvm-objdump from CLANG_EXTRAS to installed by default

We currently install three tools from binutils 2.17.50: as, ld, and
objdump. Work is underway to migrate to a permissively-licensed
tool-chain, with one goal being the retirement of binutils 2.17.50.

LLVM's llvm-objdump is intended to be compatible with GNU objdump
although it is currently missing some options and may have formatting
differences. Enable it by default for testing and further investigation.
It may later be changed to install as /usr/bin/objdump, it becomes a
fully viable replacement.

Reviewed by:	emaste
Differential Revision:	https://reviews.freebsd.org/D8879

MFC r312855 (by emaste):

Rename LLD_AS_LD to LLD_IS_LD, for consistency with CLANG_IS_CC

Reported by:	Dan McGregor <dan.mcgregor usask.ca>

MFC r313559 | glebius | 2017-02-10 18:34:48 +0100 (Fri, 10 Feb 2017) | 5 lines

Don't check struct rtentry on FreeBSD, it is an internal kernel structure.
On other systems it may be API structure for SIOCADDRT/SIOCDELRT.

Reviewed by:	emaste, dim

MFC r314152 (by jkim):

Remove an assembler flag, which is redundant since r309124.  The upstream
took care of it by introducing a macro NO_EXEC_STACK_DIRECTIVE.

http://llvm.org/viewvc/llvm-project?rev=273500&view=rev

Reviewed by:	dim

MFC r314564:

Upgrade our copies of clang, llvm, lld, lldb, compiler-rt and libc++ to
4.0.0 (branches/release_40 296509).  The release will follow soon.

Please note that from 3.5.0 onwards, clang, llvm and lldb require C++11
support to build; see UPDATING for more information.

Also note that as of 4.0.0, lld should be able to link the base system
on amd64 and aarch64.  See the WITH_LLD_IS_LLD setting in src.conf(5).
Though please be aware that this is work in progress.

Release notes for llvm, clang and lld will be available here:
<http://releases.llvm.org/4.0.0/docs/ReleaseNotes.html>
<http://releases.llvm.org/4.0.0/tools/clang/docs/ReleaseNotes.html>
<http://releases.llvm.org/4.0.0/tools/lld/docs/ReleaseNotes.html>

Thanks to Ed Maste, Jan Beich, Antoine Brodin and Eric Fiselier for
their help.

Relnotes:	yes
Exp-run:	antoine
PR:		215969, 216008

MFC r314708:

For now, revert r287232 from upstream llvm trunk (by Daniil Fukalov):

  [SCEV] limit recursion depth of CompareSCEVComplexity

  Summary:
  CompareSCEVComplexity goes too deep (50+ on a quite a big unrolled
  loop) and runs almost infinite time.

  Added cache of "equal" SCEV pairs to earlier cutoff of further
  estimation. Recursion depth limit was also introduced as a parameter.

  Reviewers: sanjoy

  Subscribers: mzolotukhin, tstellarAMD, llvm-commits

  Differential Revision: https://reviews.llvm.org/D26389

This commit is the cause of excessive compile times on skein_block.c
(and possibly other files) during kernel builds on amd64.

We never saw the problematic behavior described in this upstream commit,
so for now it is better to revert it.  An upstream bug has been filed
here: https://bugs.llvm.org/show_bug.cgi?id=32142

Reported by:	mjg

MFC r314795:

Reapply r287232 from upstream llvm trunk (by Daniil Fukalov):

  [SCEV] limit recursion depth of CompareSCEVComplexity

  Summary:
  CompareSCEVComplexity goes too deep (50+ on a quite a big unrolled
  loop) and runs almost infinite time.

  Added cache of "equal" SCEV pairs to earlier cutoff of further
  estimation. Recursion depth limit was also introduced as a parameter.

  Reviewers: sanjoy

  Subscribers: mzolotukhin, tstellarAMD, llvm-commits

  Differential Revision: https://reviews.llvm.org/D26389

Pull in r296992 from upstream llvm trunk (by Sanjoy Das):

  [SCEV] Decrease the recursion threshold for CompareValueComplexity

  Fixes PR32142.

  r287232 accidentally increased the recursion threshold for
  CompareValueComplexity from 2 to 32.  This change reverses that
  change by introducing a separate flag for CompareValueComplexity's
  threshold.

The latter revision fixes the excessive compile times for skein_block.c.

MFC r314907 | mmel | 2017-03-08 12:40:27 +0100 (Wed, 08 Mar 2017) | 7 lines

Unbreak ARMv6 world.

The new compiler_rt library imported with clang 4.0.0 have several fatal
issues (non-functional __udivsi3 for example) with ARM specific instrict
functions. As temporary workaround, until upstream solve these problems,
disable all thumb[1][2] related feature.

MFC r315016:

Update clang, llvm, lld, lldb, compiler-rt and libc++ to 4.0.0 release.
We were already very close to the last release candidate, so this is a
pretty minor update.

Relnotes:	yes

MFC r316005:

Revert r314907, and pull in r298713 from upstream compiler-rt trunk (by
Weiming Zhao):

  builtins: Select correct code fragments when compiling for Thumb1/Thum2/ARM ISA.

  Summary:
  Value of __ARM_ARCH_ISA_THUMB isn't based on the actual compilation
  mode (-mthumb, -marm), it reflect's capability of given CPU.

  Due to this:
   - use  __tbumb__ and __thumb2__ insteand of __ARM_ARCH_ISA_THUMB
   - use '.thumb' directive consistently  in all affected files
   - decorate all thumb functions using
     DEFINE_COMPILERRT_THUMB_FUNCTION()

  ---------
  Note: This patch doesn't fix broken Thumb1 variant of __udivsi3 !

  Reviewers: weimingz, rengolin, compnerd

  Subscribers: aemerson, dim

  Differential Revision: https://reviews.llvm.org/D30938

Discussed with:	mmel

1 files changed, 89 insertions, 83 deletions

diff --git a/contrib/llvm/lib/CodeGen/PrologEpilogInserter.cpp b/contrib/llvm/lib/CodeGen/PrologEpilogInserter.cpp
index 20a9a39..5fca7fa 100644
--- a/contrib/llvm/lib/CodeGen/PrologEpilogInserter.cpp
+++ b/contrib/llvm/lib/CodeGen/PrologEpilogInserter.cpp
@@ -80,7 +80,7 @@ public:
   MachineFunctionProperties getRequiredProperties() const override {
     MachineFunctionProperties MFP;
     if (UsesCalleeSaves)
-      MFP.set(MachineFunctionProperties::Property::AllVRegsAllocated);
+      MFP.set(MachineFunctionProperties::Property::NoVRegs);
     return MFP;
   }
 
@@ -117,6 +117,10 @@ private:
   // TRI->requiresFrameIndexScavenging() for the current function.
   bool FrameIndexVirtualScavenging;
 
+  // Flag to control whether the scavenger should be passed even though
+  // FrameIndexVirtualScavenging is used.
+  bool FrameIndexEliminationScavenging;
+
   void calculateCallFrameInfo(MachineFunction &Fn);
   void calculateSaveRestoreBlocks(MachineFunction &Fn);
 
@@ -176,6 +180,8 @@ bool PEI::runOnMachineFunction(MachineFunction &Fn) {
 
   RS = TRI->requiresRegisterScavenging(Fn) ? new RegScavenger() : nullptr;
   FrameIndexVirtualScavenging = TRI->requiresFrameIndexScavenging(Fn);
+  FrameIndexEliminationScavenging = (RS && !FrameIndexVirtualScavenging) ||
+    TRI->requiresFrameIndexReplacementScavenging(Fn);
 
   // Calculate the MaxCallFrameSize and AdjustsStack variables for the
   // function's frame information. Also eliminates call frame pseudo
@@ -221,8 +227,8 @@ bool PEI::runOnMachineFunction(MachineFunction &Fn) {
   }
 
   // Warn on stack size when we exceeds the given limit.
-  MachineFrameInfo *MFI = Fn.getFrameInfo();
-  uint64_t StackSize = MFI->getStackSize();
+  MachineFrameInfo &MFI = Fn.getFrameInfo();
+  uint64_t StackSize = MFI.getStackSize();
   if (WarnStackSize.getNumOccurrences() > 0 && WarnStackSize < StackSize) {
     DiagnosticInfoStackSize DiagStackSize(*F, StackSize);
     F->getContext().diagnose(DiagStackSize);
@@ -231,8 +237,8 @@ bool PEI::runOnMachineFunction(MachineFunction &Fn) {
   delete RS;
   SaveBlocks.clear();
   RestoreBlocks.clear();
-  MFI->setSavePoint(nullptr);
-  MFI->setRestorePoint(nullptr);
+  MFI.setSavePoint(nullptr);
+  MFI.setRestorePoint(nullptr);
   return true;
 }
 
@@ -242,10 +248,10 @@ bool PEI::runOnMachineFunction(MachineFunction &Fn) {
 void PEI::calculateCallFrameInfo(MachineFunction &Fn) {
   const TargetInstrInfo &TII = *Fn.getSubtarget().getInstrInfo();
   const TargetFrameLowering *TFI = Fn.getSubtarget().getFrameLowering();
-  MachineFrameInfo *MFI = Fn.getFrameInfo();
+  MachineFrameInfo &MFI = Fn.getFrameInfo();
 
   unsigned MaxCallFrameSize = 0;
-  bool AdjustsStack = MFI->adjustsStack();
+  bool AdjustsStack = MFI.adjustsStack();
 
   // Get the function call frame set-up and tear-down instruction opcode
   unsigned FrameSetupOpcode = TII.getCallFrameSetupOpcode();
@@ -274,8 +280,8 @@ void PEI::calculateCallFrameInfo(MachineFunction &Fn) {
           AdjustsStack = true;
       }
 
-  MFI->setAdjustsStack(AdjustsStack);
-  MFI->setMaxCallFrameSize(MaxCallFrameSize);
+  MFI.setAdjustsStack(AdjustsStack);
+  MFI.setMaxCallFrameSize(MaxCallFrameSize);
 
   for (std::vector<MachineBasicBlock::iterator>::iterator
          i = FrameSDOps.begin(), e = FrameSDOps.end(); i != e; ++i) {
@@ -293,17 +299,17 @@ void PEI::calculateCallFrameInfo(MachineFunction &Fn) {
 /// Compute the sets of entry and return blocks for saving and restoring
 /// callee-saved registers, and placing prolog and epilog code.
 void PEI::calculateSaveRestoreBlocks(MachineFunction &Fn) {
-  const MachineFrameInfo *MFI = Fn.getFrameInfo();
+  const MachineFrameInfo &MFI = Fn.getFrameInfo();
 
   // Even when we do not change any CSR, we still want to insert the
   // prologue and epilogue of the function.
   // So set the save points for those.
 
   // Use the points found by shrink-wrapping, if any.
-  if (MFI->getSavePoint()) {
-    SaveBlocks.push_back(MFI->getSavePoint());
-    assert(MFI->getRestorePoint() && "Both restore and save must be set");
-    MachineBasicBlock *RestoreBlock = MFI->getRestorePoint();
+  if (MFI.getSavePoint()) {
+    SaveBlocks.push_back(MFI.getSavePoint());
+    assert(MFI.getRestorePoint() && "Both restore and save must be set");
+    MachineBasicBlock *RestoreBlock = MFI.getRestorePoint();
     // If RestoreBlock does not have any successor and is not a return block
     // then the end point is unreachable and we do not need to insert any
     // epilogue.
@@ -340,7 +346,7 @@ static void assignCalleeSavedSpillSlots(MachineFunction &F,
   }
 
   const TargetFrameLowering *TFI = F.getSubtarget().getFrameLowering();
-  MachineFrameInfo *MFI = F.getFrameInfo();
+  MachineFrameInfo &MFI = F.getFrameInfo();
   if (!TFI->assignCalleeSavedSpillSlots(F, RegInfo, CSI)) {
     // If target doesn't implement this, use generic code.
 
@@ -379,26 +385,26 @@ static void assignCalleeSavedSpillSlots(MachineFunction &F,
         // the TargetRegisterClass if the stack alignment is smaller. Use the
         // min.
         Align = std::min(Align, StackAlign);
-        FrameIdx = MFI->CreateStackObject(RC->getSize(), Align, true);
+        FrameIdx = MFI.CreateStackObject(RC->getSize(), Align, true);
         if ((unsigned)FrameIdx < MinCSFrameIndex) MinCSFrameIndex = FrameIdx;
         if ((unsigned)FrameIdx > MaxCSFrameIndex) MaxCSFrameIndex = FrameIdx;
       } else {
         // Spill it to the stack where we must.
         FrameIdx =
-            MFI->CreateFixedSpillStackObject(RC->getSize(), FixedSlot->Offset);
+            MFI.CreateFixedSpillStackObject(RC->getSize(), FixedSlot->Offset);
       }
 
       CS.setFrameIdx(FrameIdx);
     }
   }
 
-  MFI->setCalleeSavedInfo(CSI);
+  MFI.setCalleeSavedInfo(CSI);
 }
 
 /// Helper function to update the liveness information for the callee-saved
 /// registers.
 static void updateLiveness(MachineFunction &MF) {
-  MachineFrameInfo *MFI = MF.getFrameInfo();
+  MachineFrameInfo &MFI = MF.getFrameInfo();
   // Visited will contain all the basic blocks that are in the region
   // where the callee saved registers are alive:
   // - Anything that is not Save or Restore -> LiveThrough.
@@ -409,7 +415,7 @@ static void updateLiveness(MachineFunction &MF) {
   SmallPtrSet<MachineBasicBlock *, 8> Visited;
   SmallVector<MachineBasicBlock *, 8> WorkList;
   MachineBasicBlock *Entry = &MF.front();
-  MachineBasicBlock *Save = MFI->getSavePoint();
+  MachineBasicBlock *Save = MFI.getSavePoint();
 
   if (!Save)
     Save = Entry;
@@ -420,7 +426,7 @@ static void updateLiveness(MachineFunction &MF) {
   }
   Visited.insert(Save);
 
-  MachineBasicBlock *Restore = MFI->getRestorePoint();
+  MachineBasicBlock *Restore = MFI.getRestorePoint();
   if (Restore)
     // By construction Restore cannot be visited, otherwise it
     // means there exists a path to Restore that does not go
@@ -440,7 +446,7 @@ static void updateLiveness(MachineFunction &MF) {
         WorkList.push_back(SuccBB);
   }
 
-  const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
+  const std::vector<CalleeSavedInfo> &CSI = MFI.getCalleeSavedInfo();
 
   for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
     for (MachineBasicBlock *MBB : Visited) {
@@ -460,10 +466,10 @@ static void insertCSRSpillsAndRestores(MachineFunction &Fn,
                                        const MBBVector &SaveBlocks,
                                        const MBBVector &RestoreBlocks) {
   // Get callee saved register information.
-  MachineFrameInfo *MFI = Fn.getFrameInfo();
-  const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
+  MachineFrameInfo &MFI = Fn.getFrameInfo();
+  const std::vector<CalleeSavedInfo> &CSI = MFI.getCalleeSavedInfo();
 
-  MFI->setCalleeSavedInfoValid(true);
+  MFI.setCalleeSavedInfoValid(true);
 
   // Early exit if no callee saved registers are modified!
   if (CSI.empty())
@@ -551,14 +557,14 @@ static void doSpillCalleeSavedRegs(MachineFunction &Fn, RegScavenger *RS,
 
 /// AdjustStackOffset - Helper function used to adjust the stack frame offset.
 static inline void
-AdjustStackOffset(MachineFrameInfo *MFI, int FrameIdx,
+AdjustStackOffset(MachineFrameInfo &MFI, int FrameIdx,
                   bool StackGrowsDown, int64_t &Offset,
                   unsigned &MaxAlign, unsigned Skew) {
   // If the stack grows down, add the object size to find the lowest address.
   if (StackGrowsDown)
-    Offset += MFI->getObjectSize(FrameIdx);
+    Offset += MFI.getObjectSize(FrameIdx);
 
-  unsigned Align = MFI->getObjectAlignment(FrameIdx);
+  unsigned Align = MFI.getObjectAlignment(FrameIdx);
 
   // If the alignment of this object is greater than that of the stack, then
   // increase the stack alignment to match.
@@ -569,11 +575,11 @@ AdjustStackOffset(MachineFrameInfo *MFI, int FrameIdx,
 
   if (StackGrowsDown) {
     DEBUG(dbgs() << "alloc FI(" << FrameIdx << ") at SP[" << -Offset << "]\n");
-    MFI->setObjectOffset(FrameIdx, -Offset); // Set the computed offset
+    MFI.setObjectOffset(FrameIdx, -Offset); // Set the computed offset
   } else {
     DEBUG(dbgs() << "alloc FI(" << FrameIdx << ") at SP[" << Offset << "]\n");
-    MFI->setObjectOffset(FrameIdx, Offset);
-    Offset += MFI->getObjectSize(FrameIdx);
+    MFI.setObjectOffset(FrameIdx, Offset);
+    Offset += MFI.getObjectSize(FrameIdx);
   }
 }
 
@@ -581,7 +587,7 @@ AdjustStackOffset(MachineFrameInfo *MFI, int FrameIdx,
 /// track of them in StackBytesFree.
 ///
 static inline void
-computeFreeStackSlots(MachineFrameInfo *MFI, bool StackGrowsDown,
+computeFreeStackSlots(MachineFrameInfo &MFI, bool StackGrowsDown,
                       unsigned MinCSFrameIndex, unsigned MaxCSFrameIndex,
                       int64_t FixedCSEnd, BitVector &StackBytesFree) {
   // Avoid undefined int64_t -> int conversion below in extreme case.
@@ -592,7 +598,7 @@ computeFreeStackSlots(MachineFrameInfo *MFI, bool StackGrowsDown,
 
   SmallVector<int, 16> AllocatedFrameSlots;
   // Add fixed objects.
-  for (int i = MFI->getObjectIndexBegin(); i != 0; ++i)
+  for (int i = MFI.getObjectIndexBegin(); i != 0; ++i)
     AllocatedFrameSlots.push_back(i);
   // Add callee-save objects.
   for (int i = MinCSFrameIndex; i <= (int)MaxCSFrameIndex; ++i)
@@ -601,8 +607,8 @@ computeFreeStackSlots(MachineFrameInfo *MFI, bool StackGrowsDown,
   for (int i : AllocatedFrameSlots) {
     // These are converted from int64_t, but they should always fit in int
     // because of the FixedCSEnd check above.
-    int ObjOffset = MFI->getObjectOffset(i);
-    int ObjSize = MFI->getObjectSize(i);
+    int ObjOffset = MFI.getObjectOffset(i);
+    int ObjSize = MFI.getObjectSize(i);
     int ObjStart, ObjEnd;
     if (StackGrowsDown) {
       // ObjOffset is negative when StackGrowsDown is true.
@@ -621,10 +627,10 @@ computeFreeStackSlots(MachineFrameInfo *MFI, bool StackGrowsDown,
 /// Assign frame object to an unused portion of the stack in the fixed stack
 /// object range.  Return true if the allocation was successful.
 ///
-static inline bool scavengeStackSlot(MachineFrameInfo *MFI, int FrameIdx,
+static inline bool scavengeStackSlot(MachineFrameInfo &MFI, int FrameIdx,
                                      bool StackGrowsDown, unsigned MaxAlign,
                                      BitVector &StackBytesFree) {
-  if (MFI->isVariableSizedObjectIndex(FrameIdx))
+  if (MFI.isVariableSizedObjectIndex(FrameIdx))
     return false;
 
   if (StackBytesFree.none()) {
@@ -634,11 +640,11 @@ static inline bool scavengeStackSlot(MachineFrameInfo *MFI, int FrameIdx,
     return false;
   }
 
-  unsigned ObjAlign = MFI->getObjectAlignment(FrameIdx);
+  unsigned ObjAlign = MFI.getObjectAlignment(FrameIdx);
   if (ObjAlign > MaxAlign)
     return false;
 
-  int64_t ObjSize = MFI->getObjectSize(FrameIdx);
+  int64_t ObjSize = MFI.getObjectSize(FrameIdx);
   int FreeStart;
   for (FreeStart = StackBytesFree.find_first(); FreeStart != -1;
        FreeStart = StackBytesFree.find_next(FreeStart)) {
@@ -668,11 +674,11 @@ static inline bool scavengeStackSlot(MachineFrameInfo *MFI, int FrameIdx,
     int ObjStart = -(FreeStart + ObjSize);
     DEBUG(dbgs() << "alloc FI(" << FrameIdx << ") scavenged at SP[" << ObjStart
                  << "]\n");
-    MFI->setObjectOffset(FrameIdx, ObjStart);
+    MFI.setObjectOffset(FrameIdx, ObjStart);
   } else {
     DEBUG(dbgs() << "alloc FI(" << FrameIdx << ") scavenged at SP[" << FreeStart
                  << "]\n");
-    MFI->setObjectOffset(FrameIdx, FreeStart);
+    MFI.setObjectOffset(FrameIdx, FreeStart);
   }
 
   StackBytesFree.reset(FreeStart, FreeStart + ObjSize);
@@ -684,7 +690,7 @@ static inline bool scavengeStackSlot(MachineFrameInfo *MFI, int FrameIdx,
 static void
 AssignProtectedObjSet(const StackObjSet &UnassignedObjs,
                       SmallSet<int, 16> &ProtectedObjs,
-                      MachineFrameInfo *MFI, bool StackGrowsDown,
+                      MachineFrameInfo &MFI, bool StackGrowsDown,
                       int64_t &Offset, unsigned &MaxAlign, unsigned Skew) {
 
   for (StackObjSet::const_iterator I = UnassignedObjs.begin(),
@@ -706,7 +712,7 @@ void PEI::calculateFrameObjectOffsets(MachineFunction &Fn) {
     TFI.getStackGrowthDirection() == TargetFrameLowering::StackGrowsDown;
 
   // Loop over all of the stack objects, assigning sequential addresses...
-  MachineFrameInfo *MFI = Fn.getFrameInfo();
+  MachineFrameInfo &MFI = Fn.getFrameInfo();
 
   // Start at the beginning of the local area.
   // The Offset is the distance from the stack top in the direction
@@ -725,17 +731,17 @@ void PEI::calculateFrameObjectOffsets(MachineFunction &Fn) {
   // non-fixed objects can't be allocated right at the start of local area.
   // Adjust 'Offset' to point to the end of last fixed sized preallocated
   // object.
-  for (int i = MFI->getObjectIndexBegin(); i != 0; ++i) {
+  for (int i = MFI.getObjectIndexBegin(); i != 0; ++i) {
     int64_t FixedOff;
     if (StackGrowsDown) {
       // The maximum distance from the stack pointer is at lower address of
       // the object -- which is given by offset. For down growing stack
       // the offset is negative, so we negate the offset to get the distance.
-      FixedOff = -MFI->getObjectOffset(i);
+      FixedOff = -MFI.getObjectOffset(i);
     } else {
       // The maximum distance from the start pointer is at the upper
       // address of the object.
-      FixedOff = MFI->getObjectOffset(i) + MFI->getObjectSize(i);
+      FixedOff = MFI.getObjectOffset(i) + MFI.getObjectSize(i);
     }
     if (FixedOff > Offset) Offset = FixedOff;
   }
@@ -746,32 +752,32 @@ void PEI::calculateFrameObjectOffsets(MachineFunction &Fn) {
     for (unsigned i = MinCSFrameIndex; i <= MaxCSFrameIndex; ++i) {
       // If the stack grows down, we need to add the size to find the lowest
       // address of the object.
-      Offset += MFI->getObjectSize(i);
+      Offset += MFI.getObjectSize(i);
 
-      unsigned Align = MFI->getObjectAlignment(i);
+      unsigned Align = MFI.getObjectAlignment(i);
       // Adjust to alignment boundary
       Offset = alignTo(Offset, Align, Skew);
 
       DEBUG(dbgs() << "alloc FI(" << i << ") at SP[" << -Offset << "]\n");
-      MFI->setObjectOffset(i, -Offset);        // Set the computed offset
+      MFI.setObjectOffset(i, -Offset);        // Set the computed offset
     }
   } else if (MaxCSFrameIndex >= MinCSFrameIndex) {
     // Be careful about underflow in comparisons agains MinCSFrameIndex.
     for (unsigned i = MaxCSFrameIndex; i != MinCSFrameIndex - 1; --i) {
-      unsigned Align = MFI->getObjectAlignment(i);
+      unsigned Align = MFI.getObjectAlignment(i);
       // Adjust to alignment boundary
       Offset = alignTo(Offset, Align, Skew);
 
       DEBUG(dbgs() << "alloc FI(" << i << ") at SP[" << Offset << "]\n");
-      MFI->setObjectOffset(i, Offset);
-      Offset += MFI->getObjectSize(i);
+      MFI.setObjectOffset(i, Offset);
+      Offset += MFI.getObjectSize(i);
     }
   }
 
   // FixedCSEnd is the stack offset to the end of the fixed and callee-save
   // stack area.
   int64_t FixedCSEnd = Offset;
-  unsigned MaxAlign = MFI->getMaxAlignment();
+  unsigned MaxAlign = MFI.getMaxAlignment();
 
   // Make sure the special register scavenging spill slot is closest to the
   // incoming stack pointer if a frame pointer is required and is closer
@@ -793,8 +799,8 @@ void PEI::calculateFrameObjectOffsets(MachineFunction &Fn) {
   // check for whether the frame is large enough to want to use virtual
   // frame index registers. Functions which don't want/need this optimization
   // will continue to use the existing code path.
-  if (MFI->getUseLocalStackAllocationBlock()) {
-    unsigned Align = MFI->getLocalFrameMaxAlign();
+  if (MFI.getUseLocalStackAllocationBlock()) {
+    unsigned Align = MFI.getLocalFrameMaxAlign();
 
     // Adjust to alignment boundary.
     Offset = alignTo(Offset, Align, Skew);
@@ -802,15 +808,15 @@ void PEI::calculateFrameObjectOffsets(MachineFunction &Fn) {
     DEBUG(dbgs() << "Local frame base offset: " << Offset << "\n");
 
     // Resolve offsets for objects in the local block.
-    for (unsigned i = 0, e = MFI->getLocalFrameObjectCount(); i != e; ++i) {
-      std::pair<int, int64_t> Entry = MFI->getLocalFrameObjectMap(i);
+    for (unsigned i = 0, e = MFI.getLocalFrameObjectCount(); i != e; ++i) {
+      std::pair<int, int64_t> Entry = MFI.getLocalFrameObjectMap(i);
       int64_t FIOffset = (StackGrowsDown ? -Offset : Offset) + Entry.second;
       DEBUG(dbgs() << "alloc FI(" << Entry.first << ") at SP[" <<
             FIOffset << "]\n");
-      MFI->setObjectOffset(Entry.first, FIOffset);
+      MFI.setObjectOffset(Entry.first, FIOffset);
     }
     // Allocate the local block
-    Offset += MFI->getLocalFrameSize();
+    Offset += MFI.getLocalFrameSize();
 
     MaxAlign = std::max(Align, MaxAlign);
   }
@@ -823,30 +829,30 @@ void PEI::calculateFrameObjectOffsets(MachineFunction &Fn) {
   // Make sure that the stack protector comes before the local variables on the
   // stack.
   SmallSet<int, 16> ProtectedObjs;
-  if (MFI->getStackProtectorIndex() >= 0) {
+  if (MFI.getStackProtectorIndex() >= 0) {
     StackObjSet LargeArrayObjs;
     StackObjSet SmallArrayObjs;
     StackObjSet AddrOfObjs;
 
-    AdjustStackOffset(MFI, MFI->getStackProtectorIndex(), StackGrowsDown,
+    AdjustStackOffset(MFI, MFI.getStackProtectorIndex(), StackGrowsDown,
                       Offset, MaxAlign, Skew);
 
     // Assign large stack objects first.
-    for (unsigned i = 0, e = MFI->getObjectIndexEnd(); i != e; ++i) {
-      if (MFI->isObjectPreAllocated(i) &&
-          MFI->getUseLocalStackAllocationBlock())
+    for (unsigned i = 0, e = MFI.getObjectIndexEnd(); i != e; ++i) {
+      if (MFI.isObjectPreAllocated(i) &&
+          MFI.getUseLocalStackAllocationBlock())
         continue;
       if (i >= MinCSFrameIndex && i <= MaxCSFrameIndex)
         continue;
       if (RS && RS->isScavengingFrameIndex((int)i))
         continue;
-      if (MFI->isDeadObjectIndex(i))
+      if (MFI.isDeadObjectIndex(i))
         continue;
-      if (MFI->getStackProtectorIndex() == (int)i ||
+      if (MFI.getStackProtectorIndex() == (int)i ||
           EHRegNodeFrameIndex == (int)i)
         continue;
 
-      switch (SP->getSSPLayout(MFI->getObjectAllocation(i))) {
+      switch (SP->getSSPLayout(MFI.getObjectAllocation(i))) {
       case StackProtector::SSPLK_None:
         continue;
       case StackProtector::SSPLK_SmallArray:
@@ -874,17 +880,16 @@ void PEI::calculateFrameObjectOffsets(MachineFunction &Fn) {
 
   // Then prepare to 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->isObjectPreAllocated(i) &&
-        MFI->getUseLocalStackAllocationBlock())
+  for (unsigned i = 0, e = MFI.getObjectIndexEnd(); i != e; ++i) {
+    if (MFI.isObjectPreAllocated(i) && MFI.getUseLocalStackAllocationBlock())
       continue;
     if (i >= MinCSFrameIndex && i <= MaxCSFrameIndex)
       continue;
     if (RS && RS->isScavengingFrameIndex((int)i))
       continue;
-    if (MFI->isDeadObjectIndex(i))
+    if (MFI.isDeadObjectIndex(i))
       continue;
-    if (MFI->getStackProtectorIndex() == (int)i ||
+    if (MFI.getStackProtectorIndex() == (int)i ||
         EHRegNodeFrameIndex == (int)i)
       continue;
     if (ProtectedObjs.count(i))
@@ -911,7 +916,7 @@ void PEI::calculateFrameObjectOffsets(MachineFunction &Fn) {
   BitVector StackBytesFree;
   if (!ObjectsToAllocate.empty() &&
       Fn.getTarget().getOptLevel() != CodeGenOpt::None &&
-      MFI->getStackProtectorIndex() < 0 && TFI.enableStackSlotScavenging(Fn))
+      MFI.getStackProtectorIndex() < 0 && TFI.enableStackSlotScavenging(Fn))
     computeFreeStackSlots(MFI, StackGrowsDown, MinCSFrameIndex, MaxCSFrameIndex,
                           FixedCSEnd, StackBytesFree);
 
@@ -935,8 +940,8 @@ void PEI::calculateFrameObjectOffsets(MachineFunction &Fn) {
     // If we have reserved argument space for call sites in the function
     // immediately on entry to the current function, count it as part of the
     // overall stack size.
-    if (MFI->adjustsStack() && TFI.hasReservedCallFrame(Fn))
-      Offset += MFI->getMaxCallFrameSize();
+    if (MFI.adjustsStack() && TFI.hasReservedCallFrame(Fn))
+      Offset += MFI.getMaxCallFrameSize();
 
     // Round up the size to a multiple of the alignment.  If the function has
     // any calls or alloca's, align to the target's StackAlignment value to
@@ -944,8 +949,8 @@ void PEI::calculateFrameObjectOffsets(MachineFunction &Fn) {
     // otherwise, for leaf functions, align to the TransientStackAlignment
     // value.
     unsigned StackAlign;
-    if (MFI->adjustsStack() || MFI->hasVarSizedObjects() ||
-        (RegInfo->needsStackRealignment(Fn) && MFI->getObjectIndexEnd() != 0))
+    if (MFI.adjustsStack() || MFI.hasVarSizedObjects() ||
+        (RegInfo->needsStackRealignment(Fn) && MFI.getObjectIndexEnd() != 0))
       StackAlign = TFI.getStackAlignment();
     else
       StackAlign = TFI.getTransientStackAlignment();
@@ -958,7 +963,7 @@ void PEI::calculateFrameObjectOffsets(MachineFunction &Fn) {
 
   // Update frame info to pretend that this is part of the stack...
   int64_t StackSize = Offset - LocalAreaOffset;
-  MFI->setStackSize(StackSize);
+  MFI.setStackSize(StackSize);
   NumBytesStackSpace += StackSize;
 }
 
@@ -1009,7 +1014,7 @@ void PEI::replaceFrameIndices(MachineFunction &Fn) {
   // Store SPAdj at exit of a basic block.
   SmallVector<int, 8> SPState;
   SPState.resize(Fn.getNumBlockIDs());
-  SmallPtrSet<MachineBasicBlock*, 8> Reachable;
+  df_iterator_default_set<MachineBasicBlock*> Reachable;
 
   // Iterate over the reachable blocks in DFS order.
   for (auto DFI = df_ext_begin(&Fn, Reachable), DFE = df_ext_end(&Fn, Reachable);
@@ -1047,7 +1052,8 @@ void PEI::replaceFrameIndices(MachineBasicBlock *BB, MachineFunction &Fn,
   unsigned FrameSetupOpcode = TII.getCallFrameSetupOpcode();
   unsigned FrameDestroyOpcode = TII.getCallFrameDestroyOpcode();
 
-  if (RS && !FrameIndexVirtualScavenging) RS->enterBasicBlock(*BB);
+  if (RS && FrameIndexEliminationScavenging)
+    RS->enterBasicBlock(*BB);
 
   bool InsideCallSequence = false;
 
@@ -1116,7 +1122,7 @@ void PEI::replaceFrameIndices(MachineBasicBlock *BB, MachineFunction &Fn,
       // use that target machine register info object to eliminate
       // it.
       TRI.eliminateFrameIndex(MI, SPAdj, i,
-                              FrameIndexVirtualScavenging ?  nullptr : RS);
+                              FrameIndexEliminationScavenging ?  RS : nullptr);
 
       // Reset the iterator if we were at the beginning of the BB.
       if (AtBeginning) {
@@ -1132,7 +1138,7 @@ void PEI::replaceFrameIndices(MachineBasicBlock *BB, MachineFunction &Fn,
     // the SP adjustment made by each instruction in the sequence.
     // This includes both the frame setup/destroy pseudos (handled above),
     // as well as other instructions that have side effects w.r.t the SP.
-    // Note that this must come after eliminateFrameIndex, because 
+    // Note that this must come after eliminateFrameIndex, because
     // if I itself referred to a frame index, we shouldn't count its own
     // adjustment.
     if (DidFinishLoop && InsideCallSequence)
@@ -1141,7 +1147,7 @@ void PEI::replaceFrameIndices(MachineBasicBlock *BB, MachineFunction &Fn,
     if (DoIncr && I != BB->end()) ++I;
 
     // Update register states.
-    if (RS && !FrameIndexVirtualScavenging && DidFinishLoop)
+    if (RS && FrameIndexEliminationScavenging && DidFinishLoop)
       RS->forward(MI);
   }
 }