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, 294 insertions, 0 deletions

diff --git a/contrib/llvm/lib/Target/X86/X86WinAllocaExpander.cpp b/contrib/llvm/lib/Target/X86/X86WinAllocaExpander.cpp
new file mode 100644
index 0000000..cc82074
--- /dev/null
+++ b/contrib/llvm/lib/Target/X86/X86WinAllocaExpander.cpp
@@ -0,0 +1,294 @@
+//===----- X86WinAllocaExpander.cpp - Expand WinAlloca pseudo instruction -===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines a pass that expands WinAlloca pseudo-instructions.
+//
+// It performs a conservative analysis to determine whether each allocation
+// falls within a region of the stack that is safe to use, or whether stack
+// probes must be emitted.
+//
+//===----------------------------------------------------------------------===//
+
+#include "X86.h"
+#include "X86InstrBuilder.h"
+#include "X86InstrInfo.h"
+#include "X86MachineFunctionInfo.h"
+#include "X86Subtarget.h"
+#include "llvm/ADT/PostOrderIterator.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/CodeGen/Passes.h"
+#include "llvm/IR/Function.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Target/TargetInstrInfo.h"
+
+using namespace llvm;
+
+namespace {
+
+class X86WinAllocaExpander : public MachineFunctionPass {
+public:
+  X86WinAllocaExpander() : MachineFunctionPass(ID) {}
+
+  bool runOnMachineFunction(MachineFunction &MF) override;
+
+private:
+  /// Strategies for lowering a WinAlloca.
+  enum Lowering { TouchAndSub, Sub, Probe };
+
+  /// Deterministic-order map from WinAlloca instruction to desired lowering.
+  typedef MapVector<MachineInstr*, Lowering> LoweringMap;
+
+  /// Compute which lowering to use for each WinAlloca instruction.
+  void computeLowerings(MachineFunction &MF, LoweringMap& Lowerings);
+
+  /// Get the appropriate lowering based on current offset and amount.
+  Lowering getLowering(int64_t CurrentOffset, int64_t AllocaAmount);
+
+  /// Lower a WinAlloca instruction.
+  void lower(MachineInstr* MI, Lowering L);
+
+  MachineRegisterInfo *MRI;
+  const X86Subtarget *STI;
+  const TargetInstrInfo *TII;
+  const X86RegisterInfo *TRI;
+  unsigned StackPtr;
+  unsigned SlotSize;
+  int64_t StackProbeSize;
+
+  const char *getPassName() const override { return "X86 WinAlloca Expander"; }
+  static char ID;
+};
+
+char X86WinAllocaExpander::ID = 0;
+
+} // end anonymous namespace
+
+FunctionPass *llvm::createX86WinAllocaExpander() {
+  return new X86WinAllocaExpander();
+}
+
+/// Return the allocation amount for a WinAlloca instruction, or -1 if unknown.
+static int64_t getWinAllocaAmount(MachineInstr *MI, MachineRegisterInfo *MRI) {
+  assert(MI->getOpcode() == X86::WIN_ALLOCA_32 ||
+         MI->getOpcode() == X86::WIN_ALLOCA_64);
+  assert(MI->getOperand(0).isReg());
+
+  unsigned AmountReg = MI->getOperand(0).getReg();
+  MachineInstr *Def = MRI->getUniqueVRegDef(AmountReg);
+
+  // Look through copies.
+  while (Def && Def->isCopy() && Def->getOperand(1).isReg())
+    Def = MRI->getUniqueVRegDef(Def->getOperand(1).getReg());
+
+  if (!Def ||
+      (Def->getOpcode() != X86::MOV32ri && Def->getOpcode() != X86::MOV64ri) ||
+      !Def->getOperand(1).isImm())
+    return -1;
+
+  return Def->getOperand(1).getImm();
+}
+
+X86WinAllocaExpander::Lowering
+X86WinAllocaExpander::getLowering(int64_t CurrentOffset,
+                                  int64_t AllocaAmount) {
+  // For a non-constant amount or a large amount, we have to probe.
+  if (AllocaAmount < 0 || AllocaAmount > StackProbeSize)
+    return Probe;
+
+  // If it fits within the safe region of the stack, just subtract.
+  if (CurrentOffset + AllocaAmount <= StackProbeSize)
+    return Sub;
+
+  // Otherwise, touch the current tip of the stack, then subtract.
+  return TouchAndSub;
+}
+
+static bool isPushPop(const MachineInstr &MI) {
+  switch (MI.getOpcode()) {
+  case X86::PUSH32i8:
+  case X86::PUSH32r:
+  case X86::PUSH32rmm:
+  case X86::PUSH32rmr:
+  case X86::PUSHi32:
+  case X86::PUSH64i8:
+  case X86::PUSH64r:
+  case X86::PUSH64rmm:
+  case X86::PUSH64rmr:
+  case X86::PUSH64i32:
+  case X86::POP32r:
+  case X86::POP64r:
+    return true;
+  default:
+    return false;
+  }
+}
+
+void X86WinAllocaExpander::computeLowerings(MachineFunction &MF,
+                                            LoweringMap &Lowerings) {
+  // Do a one-pass reverse post-order walk of the CFG to conservatively estimate
+  // the offset between the stack pointer and the lowest touched part of the
+  // stack, and use that to decide how to lower each WinAlloca instruction.
+
+  // Initialize OutOffset[B], the stack offset at exit from B, to something big.
+  DenseMap<MachineBasicBlock *, int64_t> OutOffset;
+  for (MachineBasicBlock &MBB : MF)
+    OutOffset[&MBB] = INT32_MAX;
+
+  // Note: we don't know the offset at the start of the entry block since the
+  // prologue hasn't been inserted yet, and how much that will adjust the stack
+  // pointer depends on register spills, which have not been computed yet.
+
+  // Compute the reverse post-order.
+  ReversePostOrderTraversal<MachineFunction*> RPO(&MF);
+
+  for (MachineBasicBlock *MBB : RPO) {
+    int64_t Offset = -1;
+    for (MachineBasicBlock *Pred : MBB->predecessors())
+      Offset = std::max(Offset, OutOffset[Pred]);
+    if (Offset == -1) Offset = INT32_MAX;
+
+    for (MachineInstr &MI : *MBB) {
+      if (MI.getOpcode() == X86::WIN_ALLOCA_32 ||
+          MI.getOpcode() == X86::WIN_ALLOCA_64) {
+        // A WinAlloca moves StackPtr, and potentially touches it.
+        int64_t Amount = getWinAllocaAmount(&MI, MRI);
+        Lowering L = getLowering(Offset, Amount);
+        Lowerings[&MI] = L;
+        switch (L) {
+        case Sub:
+          Offset += Amount;
+          break;
+        case TouchAndSub:
+          Offset = Amount;
+          break;
+        case Probe:
+          Offset = 0;
+          break;
+        }
+      } else if (MI.isCall() || isPushPop(MI)) {
+        // Calls, pushes and pops touch the tip of the stack.
+        Offset = 0;
+      } else if (MI.getOpcode() == X86::ADJCALLSTACKUP32 ||
+                 MI.getOpcode() == X86::ADJCALLSTACKUP64) {
+        Offset -= MI.getOperand(0).getImm();
+      } else if (MI.getOpcode() == X86::ADJCALLSTACKDOWN32 ||
+                 MI.getOpcode() == X86::ADJCALLSTACKDOWN64) {
+        Offset += MI.getOperand(0).getImm();
+      } else if (MI.modifiesRegister(StackPtr, TRI)) {
+        // Any other modification of SP means we've lost track of it.
+        Offset = INT32_MAX;
+      }
+    }
+
+    OutOffset[MBB] = Offset;
+  }
+}
+
+static unsigned getSubOpcode(bool Is64Bit, int64_t Amount) {
+  if (Is64Bit)
+    return isInt<8>(Amount) ? X86::SUB64ri8 : X86::SUB64ri32;
+  return isInt<8>(Amount) ? X86::SUB32ri8 : X86::SUB32ri;
+}
+
+void X86WinAllocaExpander::lower(MachineInstr* MI, Lowering L) {
+  DebugLoc DL = MI->getDebugLoc();
+  MachineBasicBlock *MBB = MI->getParent();
+  MachineBasicBlock::iterator I = *MI;
+
+  int64_t Amount = getWinAllocaAmount(MI, MRI);
+  if (Amount == 0) {
+    MI->eraseFromParent();
+    return;
+  }
+
+  bool Is64Bit = STI->is64Bit();
+  assert(SlotSize == 4 || SlotSize == 8);
+  unsigned RegA = (SlotSize == 8) ? X86::RAX : X86::EAX;
+
+  switch (L) {
+  case TouchAndSub:
+    assert(Amount >= SlotSize);
+
+    // Use a push to touch the top of the stack.
+    BuildMI(*MBB, I, DL, TII->get(Is64Bit ? X86::PUSH64r : X86::PUSH32r))
+        .addReg(RegA, RegState::Undef);
+    Amount -= SlotSize;
+    if (!Amount)
+      break;
+
+    // Fall through to make any remaining adjustment.
+  case Sub:
+    assert(Amount > 0);
+    if (Amount == SlotSize) {
+      // Use push to save size.
+      BuildMI(*MBB, I, DL, TII->get(Is64Bit ? X86::PUSH64r : X86::PUSH32r))
+          .addReg(RegA, RegState::Undef);
+    } else {
+      // Sub.
+      BuildMI(*MBB, I, DL, TII->get(getSubOpcode(Is64Bit, Amount)), StackPtr)
+          .addReg(StackPtr)
+          .addImm(Amount);
+    }
+    break;
+  case Probe:
+    // The probe lowering expects the amount in RAX/EAX.
+    BuildMI(*MBB, MI, DL, TII->get(TargetOpcode::COPY), RegA)
+        .addReg(MI->getOperand(0).getReg());
+
+    // Do the probe.
+    STI->getFrameLowering()->emitStackProbe(*MBB->getParent(), *MBB, MI, DL,
+                                            /*InPrologue=*/false);
+    break;
+  }
+
+  unsigned AmountReg = MI->getOperand(0).getReg();
+  MI->eraseFromParent();
+
+  // Delete the definition of AmountReg, possibly walking a chain of copies.
+  for (;;) {
+    if (!MRI->use_empty(AmountReg))
+      break;
+    MachineInstr *AmountDef = MRI->getUniqueVRegDef(AmountReg);
+    if (!AmountDef)
+      break;
+    if (AmountDef->isCopy() && AmountDef->getOperand(1).isReg())
+      AmountReg = AmountDef->getOperand(1).isReg();
+    AmountDef->eraseFromParent();
+    break;
+  }
+}
+
+bool X86WinAllocaExpander::runOnMachineFunction(MachineFunction &MF) {
+  if (!MF.getInfo<X86MachineFunctionInfo>()->hasWinAlloca())
+    return false;
+
+  MRI = &MF.getRegInfo();
+  STI = &MF.getSubtarget<X86Subtarget>();
+  TII = STI->getInstrInfo();
+  TRI = STI->getRegisterInfo();
+  StackPtr = TRI->getStackRegister();
+  SlotSize = TRI->getSlotSize();
+
+  StackProbeSize = 4096;
+  if (MF.getFunction()->hasFnAttribute("stack-probe-size")) {
+    MF.getFunction()
+        ->getFnAttribute("stack-probe-size")
+        .getValueAsString()
+        .getAsInteger(0, StackProbeSize);
+  }
+
+  LoweringMap Lowerings;
+  computeLowerings(MF, Lowerings);
+  for (auto &P : Lowerings)
+    lower(P.first, P.second);
+
+  return true;
+}