MFC r309124:

Upgrade our copies of clang, llvm, lldb, compiler-rt and libc++ to 3.9.0
release, and add lld 3.9.0.  Also completely revamp the build system for
clang, llvm, lldb and their related tools.

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

Release notes for llvm, clang and lld are available here:
<http://llvm.org/releases/3.9.0/docs/ReleaseNotes.html>
<http://llvm.org/releases/3.9.0/tools/clang/docs/ReleaseNotes.html>
<http://llvm.org/releases/3.9.0/tools/lld/docs/ReleaseNotes.html>

Thanks to Ed Maste, Bryan Drewery, Andrew Turner, Antoine Brodin and Jan
Beich for their help.

Relnotes:	yes

MFC r309147:

Pull in r282174 from upstream llvm trunk (by Krzysztof Parzyszek):

  [PPC] Set SP after loading data from stack frame, if no red zone is
  present

  Follow-up to r280705: Make sure that the SP is only restored after
  all data is loaded from the stack frame, if there is no red zone.

  This completes the fix for
  https://llvm.org/bugs/show_bug.cgi?id=26519.

  Differential Revision: https://reviews.llvm.org/D24466

Reported by:    Mark Millard
PR:             214433

MFC r309149:

Pull in r283060 from upstream llvm trunk (by Hal Finkel):

  [PowerPC] Refactor soft-float support, and enable PPC64 soft float

  This change enables soft-float for PowerPC64, and also makes
  soft-float disable all vector instruction sets for both 32-bit and
  64-bit modes. This latter part is necessary because the PPC backend
  canonicalizes many Altivec vector types to floating-point types, and
  so soft-float breaks scalarization support for many operations. Both
  for embedded targets and for operating-system kernels desiring
  soft-float support, it seems reasonable that disabling hardware
  floating-point also disables vector instructions (embedded targets
  without hardware floating point support are unlikely to have Altivec,
  etc. and operating system kernels desiring not to use floating-point
  registers to lower syscall cost are unlikely to want to use vector
  registers either). If someone needs this to work, we'll need to
  change the fact that we promote many Altivec operations to act on
  v4f32. To make it possible to disable Altivec when soft-float is
  enabled, hardware floating-point support needs to be expressed as a
  positive feature, like the others, and not a negative feature,
  because target features cannot have dependencies on the disabling of
  some other feature. So +soft-float has now become -hard-float.

  Fixes PR26970.

Pull in r283061 from upstream clang trunk (by Hal Finkel):

  [PowerPC] Enable soft-float for PPC64, and +soft-float -> -hard-float

  Enable soft-float support on PPC64, as the backend now supports it.
  Also, the backend now uses -hard-float instead of +soft-float, so set
  the target features accordingly.

  Fixes PR26970.

Reported by:	Mark Millard
PR:		214433

MFC r309212:

Add a few missed clang 3.9.0 files to OptionalObsoleteFiles.

MFC r309262:

Fix packaging for clang, lldb and lld 3.9.0

During the upgrade of clang/llvm etc to 3.9.0 in r309124, the PACKAGE
directive in the usr.bin/clang/*.mk files got dropped accidentally.

Restore it, with a few minor changes and additions:
* Correct license in clang.ucl to NCSA
* Add PACKAGE=clang for clang and most of the "ll" tools
* Put lldb in its own package
* Put lld in its own package

Reviewed by:	gjb, jmallett
Differential Revision: https://reviews.freebsd.org/D8666

MFC r309656:

During the bootstrap phase, when building the minimal llvm library on
PowerPC, add lib/Support/Atomic.cpp.  This is needed because upstream
llvm revision r271821 disabled the use of std::call_once, which causes
some fallback functions from Atomic.cpp to be used instead.

Reported by:	Mark Millard
PR:		214902

MFC r309835:

Tentatively apply https://reviews.llvm.org/D18730 to work around gcc PR
70528 (bogus error: constructor required before non-static data member).
This should fix buildworld with the external gcc package.

Reported by:	https://jenkins.freebsd.org/job/FreeBSD_HEAD_amd64_gcc/

MFC r310194:

Upgrade our copies of clang, llvm, lld, lldb, compiler-rt and libc++ to
3.9.1 release.

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

Release notes for llvm, clang and lld will be available here:
<http://releases.llvm.org/3.9.1/docs/ReleaseNotes.html>
<http://releases.llvm.org/3.9.1/tools/clang/docs/ReleaseNotes.html>
<http://releases.llvm.org/3.9.1/tools/lld/docs/ReleaseNotes.html>

Relnotes:	yes

1 files changed, 388 insertions, 0 deletions

diff --git a/contrib/llvm/lib/CodeGen/RenameIndependentSubregs.cpp b/contrib/llvm/lib/CodeGen/RenameIndependentSubregs.cpp
new file mode 100644
index 0000000..ea952d9
--- /dev/null
+++ b/contrib/llvm/lib/CodeGen/RenameIndependentSubregs.cpp
@@ -0,0 +1,388 @@
+//===-- RenameIndependentSubregs.cpp - Live Interval Analysis -------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+/// Rename independent subregisters looks for virtual registers with
+/// independently used subregisters and renames them to new virtual registers.
+/// Example: In the following:
+///   %vreg0:sub0<read-undef> = ...
+///   %vreg0:sub1 = ...
+///   use %vreg0:sub0
+///   %vreg0:sub0 = ...
+///   use %vreg0:sub0
+///   use %vreg0:sub1
+/// sub0 and sub1 are never used together, and we have two independent sub0
+/// definitions. This pass will rename to:
+///   %vreg0:sub0<read-undef> = ...
+///   %vreg1:sub1<read-undef> = ...
+///   use %vreg1:sub1
+///   %vreg2:sub1<read-undef> = ...
+///   use %vreg2:sub1
+///   use %vreg0:sub0
+//
+//===----------------------------------------------------------------------===//
+
+#include "LiveRangeUtils.h"
+#include "PHIEliminationUtils.h"
+#include "llvm/CodeGen/LiveInterval.h"
+#include "llvm/CodeGen/LiveIntervalAnalysis.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/CodeGen/Passes.h"
+#include "llvm/Target/TargetInstrInfo.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+
+using namespace llvm;
+
+#define DEBUG_TYPE "rename-independent-subregs"
+
+namespace {
+
+class RenameIndependentSubregs : public MachineFunctionPass {
+public:
+  static char ID;
+  RenameIndependentSubregs() : MachineFunctionPass(ID) {}
+
+  const char *getPassName() const override {
+    return "Rename Disconnected Subregister Components";
+  }
+
+  void getAnalysisUsage(AnalysisUsage &AU) const override {
+    AU.setPreservesCFG();
+    AU.addRequired<LiveIntervals>();
+    AU.addPreserved<LiveIntervals>();
+    AU.addRequired<SlotIndexes>();
+    AU.addPreserved<SlotIndexes>();
+    MachineFunctionPass::getAnalysisUsage(AU);
+  }
+
+  bool runOnMachineFunction(MachineFunction &MF) override;
+
+private:
+  struct SubRangeInfo {
+    ConnectedVNInfoEqClasses ConEQ;
+    LiveInterval::SubRange *SR;
+    unsigned Index;
+
+    SubRangeInfo(LiveIntervals &LIS, LiveInterval::SubRange &SR,
+                 unsigned Index)
+      : ConEQ(LIS), SR(&SR), Index(Index) {}
+  };
+
+  /// Split unrelated subregister components and rename them to new vregs.
+  bool renameComponents(LiveInterval &LI) const;
+
+  /// \brief Build a vector of SubRange infos and a union find set of
+  /// equivalence classes.
+  /// Returns true if more than 1 equivalence class was found.
+  bool findComponents(IntEqClasses &Classes,
+                      SmallVectorImpl<SubRangeInfo> &SubRangeInfos,
+                      LiveInterval &LI) const;
+
+  /// \brief Distribute the LiveInterval segments into the new LiveIntervals
+  /// belonging to their class.
+  void distribute(const IntEqClasses &Classes,
+                  const SmallVectorImpl<SubRangeInfo> &SubRangeInfos,
+                  const SmallVectorImpl<LiveInterval*> &Intervals) const;
+
+  /// \brief Constructs main liverange and add missing undef+dead flags.
+  void computeMainRangesFixFlags(const IntEqClasses &Classes,
+      const SmallVectorImpl<SubRangeInfo> &SubRangeInfos,
+      const SmallVectorImpl<LiveInterval*> &Intervals) const;
+
+  /// Rewrite Machine Operands to use the new vreg belonging to their class.
+  void rewriteOperands(const IntEqClasses &Classes,
+                       const SmallVectorImpl<SubRangeInfo> &SubRangeInfos,
+                       const SmallVectorImpl<LiveInterval*> &Intervals) const;
+
+
+  LiveIntervals *LIS;
+  MachineRegisterInfo *MRI;
+  const TargetInstrInfo *TII;
+};
+
+} // end anonymous namespace
+
+char RenameIndependentSubregs::ID;
+
+char &llvm::RenameIndependentSubregsID = RenameIndependentSubregs::ID;
+
+INITIALIZE_PASS_BEGIN(RenameIndependentSubregs, "rename-independent-subregs",
+                      "Rename Independent Subregisters", false, false)
+INITIALIZE_PASS_DEPENDENCY(SlotIndexes)
+INITIALIZE_PASS_DEPENDENCY(LiveIntervals)
+INITIALIZE_PASS_END(RenameIndependentSubregs, "rename-independent-subregs",
+                    "Rename Independent Subregisters", false, false)
+
+bool RenameIndependentSubregs::renameComponents(LiveInterval &LI) const {
+  // Shortcut: We cannot have split components with a single definition.
+  if (LI.valnos.size() < 2)
+    return false;
+
+  SmallVector<SubRangeInfo, 4> SubRangeInfos;
+  IntEqClasses Classes;
+  if (!findComponents(Classes, SubRangeInfos, LI))
+    return false;
+
+  // Create a new VReg for each class.
+  unsigned Reg = LI.reg;
+  const TargetRegisterClass *RegClass = MRI->getRegClass(Reg);
+  SmallVector<LiveInterval*, 4> Intervals;
+  Intervals.push_back(&LI);
+  DEBUG(dbgs() << PrintReg(Reg) << ": Found " << Classes.getNumClasses()
+        << " equivalence classes.\n");
+  DEBUG(dbgs() << PrintReg(Reg) << ": Splitting into newly created:");
+  for (unsigned I = 1, NumClasses = Classes.getNumClasses(); I < NumClasses;
+       ++I) {
+    unsigned NewVReg = MRI->createVirtualRegister(RegClass);
+    LiveInterval &NewLI = LIS->createEmptyInterval(NewVReg);
+    Intervals.push_back(&NewLI);
+    DEBUG(dbgs() << ' ' << PrintReg(NewVReg));
+  }
+  DEBUG(dbgs() << '\n');
+
+  rewriteOperands(Classes, SubRangeInfos, Intervals);
+  distribute(Classes, SubRangeInfos, Intervals);
+  computeMainRangesFixFlags(Classes, SubRangeInfos, Intervals);
+  return true;
+}
+
+bool RenameIndependentSubregs::findComponents(IntEqClasses &Classes,
+    SmallVectorImpl<RenameIndependentSubregs::SubRangeInfo> &SubRangeInfos,
+    LiveInterval &LI) const {
+  // First step: Create connected components for the VNInfos inside the
+  // subranges and count the global number of such components.
+  unsigned NumComponents = 0;
+  for (LiveInterval::SubRange &SR : LI.subranges()) {
+    SubRangeInfos.push_back(SubRangeInfo(*LIS, SR, NumComponents));
+    ConnectedVNInfoEqClasses &ConEQ = SubRangeInfos.back().ConEQ;
+
+    unsigned NumSubComponents = ConEQ.Classify(SR);
+    NumComponents += NumSubComponents;
+  }
+  // Shortcut: With only 1 subrange, the normal separate component tests are
+  // enough and we do not need to perform the union-find on the subregister
+  // segments.
+  if (SubRangeInfos.size() < 2)
+    return false;
+
+  // Next step: Build union-find structure over all subranges and merge classes
+  // across subranges when they are affected by the same MachineOperand.
+  const TargetRegisterInfo &TRI = *MRI->getTargetRegisterInfo();
+  Classes.grow(NumComponents);
+  unsigned Reg = LI.reg;
+  for (const MachineOperand &MO : MRI->reg_nodbg_operands(Reg)) {
+    if (!MO.isDef() && !MO.readsReg())
+      continue;
+    unsigned SubRegIdx = MO.getSubReg();
+    LaneBitmask LaneMask = TRI.getSubRegIndexLaneMask(SubRegIdx);
+    unsigned MergedID = ~0u;
+    for (RenameIndependentSubregs::SubRangeInfo &SRInfo : SubRangeInfos) {
+      const LiveInterval::SubRange &SR = *SRInfo.SR;
+      if ((SR.LaneMask & LaneMask) == 0)
+        continue;
+      SlotIndex Pos = LIS->getInstructionIndex(*MO.getParent());
+      Pos = MO.isDef() ? Pos.getRegSlot(MO.isEarlyClobber())
+                       : Pos.getBaseIndex();
+      const VNInfo *VNI = SR.getVNInfoAt(Pos);
+      if (VNI == nullptr)
+        continue;
+
+      // Map to local representant ID.
+      unsigned LocalID = SRInfo.ConEQ.getEqClass(VNI);
+      // Global ID
+      unsigned ID = LocalID + SRInfo.Index;
+      // Merge other sets
+      MergedID = MergedID == ~0u ? ID : Classes.join(MergedID, ID);
+    }
+  }
+
+  // Early exit if we ended up with a single equivalence class.
+  Classes.compress();
+  unsigned NumClasses = Classes.getNumClasses();
+  return NumClasses > 1;
+}
+
+void RenameIndependentSubregs::rewriteOperands(const IntEqClasses &Classes,
+    const SmallVectorImpl<SubRangeInfo> &SubRangeInfos,
+    const SmallVectorImpl<LiveInterval*> &Intervals) const {
+  const TargetRegisterInfo &TRI = *MRI->getTargetRegisterInfo();
+  unsigned Reg = Intervals[0]->reg;;
+  for (MachineRegisterInfo::reg_nodbg_iterator I = MRI->reg_nodbg_begin(Reg),
+       E = MRI->reg_nodbg_end(); I != E; ) {
+    MachineOperand &MO = *I++;
+    if (!MO.isDef() && !MO.readsReg())
+      continue;
+
+    MachineInstr &MI = *MO.getParent();
+
+    SlotIndex Pos = LIS->getInstructionIndex(MI);
+    unsigned SubRegIdx = MO.getSubReg();
+    LaneBitmask LaneMask = TRI.getSubRegIndexLaneMask(SubRegIdx);
+
+    unsigned ID = ~0u;
+    for (const SubRangeInfo &SRInfo : SubRangeInfos) {
+      const LiveInterval::SubRange &SR = *SRInfo.SR;
+      if ((SR.LaneMask & LaneMask) == 0)
+        continue;
+      LiveRange::const_iterator I = SR.find(Pos);
+      if (I == SR.end())
+        continue;
+
+      const VNInfo &VNI = *I->valno;
+      // Map to local representant ID.
+      unsigned LocalID = SRInfo.ConEQ.getEqClass(&VNI);
+      // Global ID
+      ID = Classes[LocalID + SRInfo.Index];
+      break;
+    }
+
+    unsigned VReg = Intervals[ID]->reg;
+    MO.setReg(VReg);
+  }
+  // TODO: We could attempt to recompute new register classes while visiting
+  // the operands: Some of the split register may be fine with less constraint
+  // classes than the original vreg.
+}
+
+void RenameIndependentSubregs::distribute(const IntEqClasses &Classes,
+    const SmallVectorImpl<SubRangeInfo> &SubRangeInfos,
+    const SmallVectorImpl<LiveInterval*> &Intervals) const {
+  unsigned NumClasses = Classes.getNumClasses();
+  SmallVector<unsigned, 8> VNIMapping;
+  SmallVector<LiveInterval::SubRange*, 8> SubRanges;
+  BumpPtrAllocator &Allocator = LIS->getVNInfoAllocator();
+  for (const SubRangeInfo &SRInfo : SubRangeInfos) {
+    LiveInterval::SubRange &SR = *SRInfo.SR;
+    unsigned NumValNos = SR.valnos.size();
+    VNIMapping.clear();
+    VNIMapping.reserve(NumValNos);
+    SubRanges.clear();
+    SubRanges.resize(NumClasses-1, nullptr);
+    for (unsigned I = 0; I < NumValNos; ++I) {
+      const VNInfo &VNI = *SR.valnos[I];
+      unsigned LocalID = SRInfo.ConEQ.getEqClass(&VNI);
+      unsigned ID = Classes[LocalID + SRInfo.Index];
+      VNIMapping.push_back(ID);
+      if (ID > 0 && SubRanges[ID-1] == nullptr)
+        SubRanges[ID-1] = Intervals[ID]->createSubRange(Allocator, SR.LaneMask);
+    }
+    DistributeRange(SR, SubRanges.data(), VNIMapping);
+  }
+}
+
+static bool subRangeLiveAt(const LiveInterval &LI, SlotIndex Pos) {
+  for (const LiveInterval::SubRange &SR : LI.subranges()) {
+    if (SR.liveAt(Pos))
+      return true;
+  }
+  return false;
+}
+
+void RenameIndependentSubregs::computeMainRangesFixFlags(
+    const IntEqClasses &Classes,
+    const SmallVectorImpl<SubRangeInfo> &SubRangeInfos,
+    const SmallVectorImpl<LiveInterval*> &Intervals) const {
+  BumpPtrAllocator &Allocator = LIS->getVNInfoAllocator();
+  const SlotIndexes &Indexes = *LIS->getSlotIndexes();
+  for (size_t I = 0, E = Intervals.size(); I < E; ++I) {
+    LiveInterval &LI = *Intervals[I];
+    unsigned Reg = LI.reg;
+
+    LI.removeEmptySubRanges();
+
+    // There must be a def (or live-in) before every use. Splitting vregs may
+    // violate this principle as the splitted vreg may not have a definition on
+    // every path. Fix this by creating IMPLICIT_DEF instruction as necessary.
+    for (const LiveInterval::SubRange &SR : LI.subranges()) {
+      // Search for "PHI" value numbers in the subranges. We must find a live
+      // value in each predecessor block, add an IMPLICIT_DEF where it is
+      // missing.
+      for (unsigned I = 0; I < SR.valnos.size(); ++I) {
+        const VNInfo &VNI = *SR.valnos[I];
+        if (VNI.isUnused() || !VNI.isPHIDef())
+          continue;
+
+        SlotIndex Def = VNI.def;
+        MachineBasicBlock &MBB = *Indexes.getMBBFromIndex(Def);
+        for (MachineBasicBlock *PredMBB : MBB.predecessors()) {
+          SlotIndex PredEnd = Indexes.getMBBEndIdx(PredMBB);
+          if (subRangeLiveAt(LI, PredEnd.getPrevSlot()))
+            continue;
+
+          MachineBasicBlock::iterator InsertPos =
+            llvm::findPHICopyInsertPoint(PredMBB, &MBB, Reg);
+          const MCInstrDesc &MCDesc = TII->get(TargetOpcode::IMPLICIT_DEF);
+          MachineInstrBuilder ImpDef = BuildMI(*PredMBB, InsertPos,
+                                               DebugLoc(), MCDesc, Reg);
+          SlotIndex DefIdx = LIS->InsertMachineInstrInMaps(*ImpDef);
+          SlotIndex RegDefIdx = DefIdx.getRegSlot();
+          for (LiveInterval::SubRange &SR : LI.subranges()) {
+            VNInfo *SRVNI = SR.getNextValue(RegDefIdx, Allocator);
+            SR.addSegment(LiveRange::Segment(RegDefIdx, PredEnd, SRVNI));
+          }
+        }
+      }
+    }
+
+    for (MachineOperand &MO : MRI->reg_nodbg_operands(Reg)) {
+      if (!MO.isDef())
+        continue;
+      unsigned SubRegIdx = MO.getSubReg();
+      if (SubRegIdx == 0)
+        continue;
+      // After assigning the new vreg we may not have any other sublanes living
+      // in and out of the instruction anymore. We need to add new dead and
+      // undef flags in these cases.
+      if (!MO.isUndef()) {
+        SlotIndex Pos = LIS->getInstructionIndex(*MO.getParent());
+        if (!subRangeLiveAt(LI, Pos))
+          MO.setIsUndef();
+      }
+      if (!MO.isDead()) {
+        SlotIndex Pos = LIS->getInstructionIndex(*MO.getParent()).getDeadSlot();
+        if (!subRangeLiveAt(LI, Pos))
+          MO.setIsDead();
+      }
+    }
+
+    if (I == 0)
+      LI.clear();
+    LIS->constructMainRangeFromSubranges(LI);
+  }
+}
+
+bool RenameIndependentSubregs::runOnMachineFunction(MachineFunction &MF) {
+  // Skip renaming if liveness of subregister is not tracked.
+  if (!MF.getSubtarget().enableSubRegLiveness())
+    return false;
+
+  DEBUG(dbgs() << "Renaming independent subregister live ranges in "
+        << MF.getName() << '\n');
+
+  LIS = &getAnalysis<LiveIntervals>();
+  MRI = &MF.getRegInfo();
+  TII = MF.getSubtarget().getInstrInfo();
+
+  // Iterate over all vregs. Note that we query getNumVirtRegs() the newly
+  // created vregs end up with higher numbers but do not need to be visited as
+  // there can't be any further splitting.
+  bool Changed = false;
+  for (size_t I = 0, E = MRI->getNumVirtRegs(); I < E; ++I) {
+    unsigned Reg = TargetRegisterInfo::index2VirtReg(I);
+    if (!LIS->hasInterval(Reg))
+      continue;
+    LiveInterval &LI = LIS->getInterval(Reg);
+    if (!LI.hasSubRanges())
+      continue;
+
+    Changed |= renameComponents(LI);
+  }
+
+  return Changed;
+}