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, 186 insertions, 0 deletions

diff --git a/contrib/llvm/lib/Target/X86/X86FixupSetCC.cpp b/contrib/llvm/lib/Target/X86/X86FixupSetCC.cpp
new file mode 100644
index 0000000..fb317da
--- /dev/null
+++ b/contrib/llvm/lib/Target/X86/X86FixupSetCC.cpp
@@ -0,0 +1,186 @@
+//===---- X86FixupSetCC.cpp - optimize usage of LEA instructions ----------===//
+//
+//                     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 fixes zero-extension of setcc patterns.
+// X86 setcc instructions are modeled to have no input arguments, and a single
+// GR8 output argument. This is consistent with other similar instructions
+// (e.g. movb), but means it is impossible to directly generate a setcc into
+// the lower GR8 of a specified GR32.
+// This means that ISel must select (zext (setcc)) into something like
+// seta %al; movzbl %al, %eax.
+// Unfortunately, this can cause a stall due to the partial register write
+// performed by the setcc. Instead, we can use:
+// xor %eax, %eax; seta %al
+// This both avoids the stall, and encodes shorter.
+//===----------------------------------------------------------------------===//
+
+#include "X86.h"
+#include "X86InstrInfo.h"
+#include "X86Subtarget.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+
+using namespace llvm;
+
+#define DEBUG_TYPE "x86-fixup-setcc"
+
+STATISTIC(NumSubstZexts, "Number of setcc + zext pairs substituted");
+
+namespace {
+class X86FixupSetCCPass : public MachineFunctionPass {
+public:
+  X86FixupSetCCPass() : MachineFunctionPass(ID) {}
+
+  const char *getPassName() const override { return "X86 Fixup SetCC"; }
+
+  bool runOnMachineFunction(MachineFunction &MF) override;
+
+private:
+  // Find the preceding instruction that imp-defs eflags.
+  MachineInstr *findFlagsImpDef(MachineBasicBlock *MBB,
+                                MachineBasicBlock::reverse_iterator MI);
+
+  // Return true if MI imp-uses eflags.
+  bool impUsesFlags(MachineInstr *MI);
+
+  // Return true if this is the opcode of a SetCC instruction with a register
+  // output.
+  bool isSetCCr(unsigned Opode);
+
+  MachineRegisterInfo *MRI;
+  const X86InstrInfo *TII;
+
+  enum { SearchBound = 16 };
+
+  static char ID;
+};
+
+char X86FixupSetCCPass::ID = 0;
+}
+
+FunctionPass *llvm::createX86FixupSetCC() { return new X86FixupSetCCPass(); }
+
+bool X86FixupSetCCPass::isSetCCr(unsigned Opcode) {
+  switch (Opcode) {
+  default:
+    return false;
+  case X86::SETOr:
+  case X86::SETNOr:
+  case X86::SETBr:
+  case X86::SETAEr:
+  case X86::SETEr:
+  case X86::SETNEr:
+  case X86::SETBEr:
+  case X86::SETAr:
+  case X86::SETSr:
+  case X86::SETNSr:
+  case X86::SETPr:
+  case X86::SETNPr:
+  case X86::SETLr:
+  case X86::SETGEr:
+  case X86::SETLEr:
+  case X86::SETGr:
+    return true;
+  }
+}
+
+// We expect the instruction *immediately* before the setcc to imp-def
+// EFLAGS (because of scheduling glue). To make this less brittle w.r.t
+// scheduling, look backwards until we hit the beginning of the
+// basic-block, or a small bound (to avoid quadratic behavior).
+MachineInstr *
+X86FixupSetCCPass::findFlagsImpDef(MachineBasicBlock *MBB,
+                                   MachineBasicBlock::reverse_iterator MI) {
+  auto MBBStart = MBB->instr_rend();
+  for (int i = 0; (i < SearchBound) && (MI != MBBStart); ++i, ++MI)
+    for (auto &Op : MI->implicit_operands())
+      if ((Op.getReg() == X86::EFLAGS) && (Op.isDef()))
+        return &*MI;
+
+  return nullptr;
+}
+
+bool X86FixupSetCCPass::impUsesFlags(MachineInstr *MI) {
+  for (auto &Op : MI->implicit_operands())
+    if ((Op.getReg() == X86::EFLAGS) && (Op.isUse()))
+      return true;
+
+  return false;
+}
+
+bool X86FixupSetCCPass::runOnMachineFunction(MachineFunction &MF) {
+  bool Changed = false;
+  MRI = &MF.getRegInfo();
+  TII = MF.getSubtarget<X86Subtarget>().getInstrInfo();
+
+  SmallVector<MachineInstr*, 4> ToErase;
+
+  for (auto &MBB : MF) {
+    for (auto &MI : MBB) {
+      // Find a setcc that is used by a zext.
+      // This doesn't have to be the only use, the transformation is safe
+      // regardless.
+      if (!isSetCCr(MI.getOpcode()))
+        continue;
+
+      MachineInstr *ZExt = nullptr;
+      for (auto &Use : MRI->use_instructions(MI.getOperand(0).getReg()))
+        if (Use.getOpcode() == X86::MOVZX32rr8)
+          ZExt = &Use;
+
+      if (!ZExt)
+        continue;
+
+      // Find the preceding instruction that imp-defs eflags.
+      MachineInstr *FlagsDefMI = findFlagsImpDef(
+          MI.getParent(), MachineBasicBlock::reverse_iterator(&MI));
+      if (!FlagsDefMI)
+        continue;
+
+      // We'd like to put something that clobbers eflags directly before
+      // FlagsDefMI. This can't hurt anything after FlagsDefMI, because
+      // it, itself, by definition, clobbers eflags. But it may happen that
+      // FlagsDefMI also *uses* eflags, in which case the transformation is
+      // invalid.
+      if (impUsesFlags(FlagsDefMI))
+        continue;
+
+      ++NumSubstZexts;
+      Changed = true;
+
+      // On 32-bit, we need to be careful to force an ABCD register.
+      const TargetRegisterClass *RC = MF.getSubtarget<X86Subtarget>().is64Bit()
+                                          ? &X86::GR32RegClass
+                                          : &X86::GR32_ABCDRegClass;
+      unsigned ZeroReg = MRI->createVirtualRegister(RC);
+      unsigned InsertReg = MRI->createVirtualRegister(RC);
+
+      // Initialize a register with 0. This must go before the eflags def
+      BuildMI(MBB, FlagsDefMI, MI.getDebugLoc(), TII->get(X86::MOV32r0),
+              ZeroReg);
+
+      // X86 setcc only takes an output GR8, so fake a GR32 input by inserting
+      // the setcc result into the low byte of the zeroed register.
+      BuildMI(*ZExt->getParent(), ZExt, ZExt->getDebugLoc(),
+              TII->get(X86::INSERT_SUBREG), InsertReg)
+          .addReg(ZeroReg)
+          .addReg(MI.getOperand(0).getReg())
+          .addImm(X86::sub_8bit);
+      MRI->replaceRegWith(ZExt->getOperand(0).getReg(), InsertReg);
+      ToErase.push_back(ZExt);
+    }
+  }
+
+  for (auto &I : ToErase)
+    I->eraseFromParent();
+
+  return Changed;
+}