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, 337 insertions, 0 deletions

diff --git a/contrib/llvm/lib/Target/SystemZ/SystemZHazardRecognizer.cpp b/contrib/llvm/lib/Target/SystemZ/SystemZHazardRecognizer.cpp
new file mode 100644
index 0000000..fe4b52b
--- /dev/null
+++ b/contrib/llvm/lib/Target/SystemZ/SystemZHazardRecognizer.cpp
@@ -0,0 +1,337 @@
+//=-- SystemZHazardRecognizer.h - SystemZ Hazard Recognizer -----*- C++ -*-===//
+//
+//                     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 hazard recognizer for the SystemZ scheduler.
+//
+// This class is used by the SystemZ scheduling strategy to maintain
+// the state during scheduling, and provide cost functions for
+// scheduling candidates. This includes:
+//
+// * Decoder grouping. A decoder group can maximally hold 3 uops, and
+// instructions that always begin a new group should be scheduled when
+// the current decoder group is empty.
+// * Processor resources usage. It is beneficial to balance the use of
+// resources.
+//
+// ===---------------------------------------------------------------------===//
+
+#include "SystemZHazardRecognizer.h"
+#include "llvm/ADT/Statistic.h"
+
+using namespace llvm;
+
+#define DEBUG_TYPE "misched"
+
+// This is the limit of processor resource usage at which the
+// scheduler should try to look for other instructions (not using the
+// critical resource).
+static cl::opt<int> ProcResCostLim("procres-cost-lim", cl::Hidden,
+                                   cl::desc("The OOO window for processor "
+                                            "resources during scheduling."),
+                                   cl::init(8));
+
+SystemZHazardRecognizer::
+SystemZHazardRecognizer(const MachineSchedContext *C) : DAG(nullptr),
+                                                        SchedModel(nullptr) {}
+
+unsigned SystemZHazardRecognizer::
+getNumDecoderSlots(SUnit *SU) const {
+  const MCSchedClassDesc *SC = DAG->getSchedClass(SU);
+  if (!SC->isValid())
+    return 0; // IMPLICIT_DEF / KILL -- will not make impact in output.
+
+  if (SC->BeginGroup) {
+    if (!SC->EndGroup)
+      return 2; // Cracked instruction
+    else
+      return 3; // Expanded/group-alone instruction
+  }
+    
+  return 1; // Normal instruction
+}
+
+unsigned SystemZHazardRecognizer::getCurrCycleIdx() {
+  unsigned Idx = CurrGroupSize;
+  if (GrpCount % 2)
+    Idx += 3;
+  return Idx;
+}
+
+ScheduleHazardRecognizer::HazardType SystemZHazardRecognizer::
+getHazardType(SUnit *m, int Stalls) {
+  return (fitsIntoCurrentGroup(m) ? NoHazard : Hazard);
+}
+
+void SystemZHazardRecognizer::Reset() {
+  CurrGroupSize = 0;
+  clearProcResCounters();
+  GrpCount = 0;
+  LastFPdOpCycleIdx = UINT_MAX;
+  DEBUG(CurGroupDbg = "";);
+}
+
+bool
+SystemZHazardRecognizer::fitsIntoCurrentGroup(SUnit *SU) const {
+  const MCSchedClassDesc *SC = DAG->getSchedClass(SU);
+  if (!SC->isValid())
+    return true;
+
+  // A cracked instruction only fits into schedule if the current
+  // group is empty.
+  if (SC->BeginGroup)
+    return (CurrGroupSize == 0);
+
+  // Since a full group is handled immediately in EmitInstruction(),
+  // SU should fit into current group. NumSlots should be 1 or 0,
+  // since it is not a cracked or expanded instruction.
+  assert ((getNumDecoderSlots(SU) <= 1) && (CurrGroupSize < 3) &&
+          "Expected normal instruction to fit in non-full group!");
+
+  return true;
+}
+
+void SystemZHazardRecognizer::nextGroup(bool DbgOutput) {
+  if (CurrGroupSize > 0) {
+    DEBUG(dumpCurrGroup("Completed decode group"));
+    DEBUG(CurGroupDbg = "";);
+
+    GrpCount++;
+
+    // Reset counter for next group.
+    CurrGroupSize = 0;
+
+    // Decrease counters for execution units by one.
+    for (unsigned i = 0; i < SchedModel->getNumProcResourceKinds(); ++i)
+      if (ProcResourceCounters[i] > 0)
+        ProcResourceCounters[i]--;
+
+    // Clear CriticalResourceIdx if it is now below the threshold.
+    if (CriticalResourceIdx != UINT_MAX &&
+        (ProcResourceCounters[CriticalResourceIdx] <=
+         ProcResCostLim))
+      CriticalResourceIdx = UINT_MAX;
+  }
+
+  DEBUG(if (DbgOutput)
+          dumpProcResourceCounters(););
+}
+
+#ifndef NDEBUG // Debug output
+void SystemZHazardRecognizer::dumpSU(SUnit *SU, raw_ostream &OS) const {
+  OS << "SU(" << SU->NodeNum << "):";
+  OS << SchedModel->getInstrInfo()->getName(SU->getInstr()->getOpcode());
+
+  const MCSchedClassDesc *SC = DAG->getSchedClass(SU);
+  if (!SC->isValid())
+    return;
+  
+  for (TargetSchedModel::ProcResIter
+         PI = SchedModel->getWriteProcResBegin(SC),
+         PE = SchedModel->getWriteProcResEnd(SC); PI != PE; ++PI) {
+    const MCProcResourceDesc &PRD =
+      *SchedModel->getProcResource(PI->ProcResourceIdx);
+    std::string FU(PRD.Name);
+    // trim e.g. Z13_FXaUnit -> FXa
+    FU = FU.substr(FU.find("_") + 1);
+    FU.resize(FU.find("Unit"));
+    OS << "/" << FU;
+
+    if (PI->Cycles > 1)
+      OS << "(" << PI->Cycles << "cyc)";
+  }
+
+  if (SC->NumMicroOps > 1)
+    OS << "/" << SC->NumMicroOps << "uops";
+  if (SC->BeginGroup && SC->EndGroup)
+    OS << "/GroupsAlone";
+  else if (SC->BeginGroup)
+    OS << "/BeginsGroup";
+  else if (SC->EndGroup)
+    OS << "/EndsGroup";
+  if (SU->isUnbuffered)
+    OS << "/Unbuffered";
+}
+
+void SystemZHazardRecognizer::dumpCurrGroup(std::string Msg) const {
+  dbgs() << "+++ " << Msg;
+  dbgs() << ": ";
+
+  if (CurGroupDbg.empty())
+    dbgs() << " <empty>\n";
+  else {
+    dbgs() << "{ " << CurGroupDbg << " }";
+    dbgs() << " (" << CurrGroupSize << " decoder slot"
+           << (CurrGroupSize > 1 ? "s":"")
+           << ")\n";
+  }
+}
+
+void SystemZHazardRecognizer::dumpProcResourceCounters() const {
+  bool any = false;
+
+  for (unsigned i = 0; i < SchedModel->getNumProcResourceKinds(); ++i)
+    if (ProcResourceCounters[i] > 0) {
+      any = true;
+      break;
+    }
+
+  if (!any)
+    return;
+
+  dbgs() << "+++ Resource counters:\n";
+  for (unsigned i = 0; i < SchedModel->getNumProcResourceKinds(); ++i)
+    if (ProcResourceCounters[i] > 0) {
+      dbgs() << "+++ Extra schedule for execution unit "
+             << SchedModel->getProcResource(i)->Name
+             << ": " << ProcResourceCounters[i] << "\n";
+      any = true;
+    }
+}
+#endif //NDEBUG
+
+void SystemZHazardRecognizer::clearProcResCounters() {
+  ProcResourceCounters.assign(SchedModel->getNumProcResourceKinds(), 0);
+  CriticalResourceIdx = UINT_MAX;
+}
+
+// Update state with SU as the next scheduled unit.
+void SystemZHazardRecognizer::
+EmitInstruction(SUnit *SU) {
+  const MCSchedClassDesc *SC = DAG->getSchedClass(SU);
+  DEBUG( dumpCurrGroup("Decode group before emission"););
+
+  // If scheduling an SU that must begin a new decoder group, move on
+  // to next group.
+  if (!fitsIntoCurrentGroup(SU))
+    nextGroup();
+
+  DEBUG( dbgs() << "+++ HazardRecognizer emitting "; dumpSU(SU, dbgs());
+         dbgs() << "\n";
+         raw_string_ostream cgd(CurGroupDbg);
+         if (CurGroupDbg.length())
+           cgd << ", ";
+         dumpSU(SU, cgd););
+
+  // After returning from a call, we don't know much about the state.
+  if (SU->getInstr()->isCall()) {
+    DEBUG (dbgs() << "+++ Clearing state after call.\n";);
+    clearProcResCounters();
+    LastFPdOpCycleIdx = UINT_MAX;
+    CurrGroupSize += getNumDecoderSlots(SU);
+    assert (CurrGroupSize <= 3);
+    nextGroup();
+    return;
+  }
+
+  // Increase counter for execution unit(s).
+  for (TargetSchedModel::ProcResIter
+         PI = SchedModel->getWriteProcResBegin(SC),
+         PE = SchedModel->getWriteProcResEnd(SC); PI != PE; ++PI) {
+    // Don't handle FPd together with the other resources.
+    if (SchedModel->getProcResource(PI->ProcResourceIdx)->BufferSize == 1)
+      continue;
+    int &CurrCounter =
+      ProcResourceCounters[PI->ProcResourceIdx];
+    CurrCounter += PI->Cycles;
+    // Check if this is now the new critical resource.
+    if ((CurrCounter > ProcResCostLim) &&
+        (CriticalResourceIdx == UINT_MAX ||
+         (PI->ProcResourceIdx != CriticalResourceIdx &&
+          CurrCounter >
+          ProcResourceCounters[CriticalResourceIdx]))) {
+      DEBUG( dbgs() << "+++ New critical resource: "
+             << SchedModel->getProcResource(PI->ProcResourceIdx)->Name
+             << "\n";);
+      CriticalResourceIdx = PI->ProcResourceIdx;
+    }
+  }
+
+  // Make note of an instruction that uses a blocking resource (FPd).
+  if (SU->isUnbuffered) {
+    LastFPdOpCycleIdx = getCurrCycleIdx();
+    DEBUG (dbgs() << "+++ Last FPd cycle index: "
+           << LastFPdOpCycleIdx << "\n";);
+  }
+
+  // Insert SU into current group by increasing number of slots used
+  // in current group.
+  CurrGroupSize += getNumDecoderSlots(SU);
+  assert (CurrGroupSize <= 3);
+
+  // Check if current group is now full/ended. If so, move on to next
+  // group to be ready to evaluate more candidates.
+  if (CurrGroupSize == 3 || SC->EndGroup)
+    nextGroup();
+}
+
+int SystemZHazardRecognizer::groupingCost(SUnit *SU) const {
+  const MCSchedClassDesc *SC = DAG->getSchedClass(SU);
+  if (!SC->isValid())
+    return 0;
+  
+  // If SU begins new group, it can either break a current group early
+  // or fit naturally if current group is empty (negative cost).
+  if (SC->BeginGroup) {
+    if (CurrGroupSize)
+      return 3 - CurrGroupSize;
+    return -1;
+  }
+
+  // Similarly, a group-ending SU may either fit well (last in group), or
+  // end the group prematurely.
+  if (SC->EndGroup) {
+    unsigned resultingGroupSize =
+      (CurrGroupSize + getNumDecoderSlots(SU));
+    if (resultingGroupSize < 3)
+      return (3 - resultingGroupSize);
+    return -1;
+  }
+
+  // Most instructions can be placed in any decoder slot.
+  return 0;
+}
+
+bool SystemZHazardRecognizer::isFPdOpPreferred_distance(const SUnit *SU) {
+  assert (SU->isUnbuffered);
+  // If this is the first FPd op, it should be scheduled high.
+  if (LastFPdOpCycleIdx == UINT_MAX)
+    return true;
+  // If this is not the first PFd op, it should go into the other side
+  // of the processor to use the other FPd unit there. This should
+  // generally happen if two FPd ops are placed with 2 other
+  // instructions between them (modulo 6).
+  if (LastFPdOpCycleIdx > getCurrCycleIdx())
+    return ((LastFPdOpCycleIdx - getCurrCycleIdx()) == 3);
+  return ((getCurrCycleIdx() - LastFPdOpCycleIdx) == 3);
+}
+
+int SystemZHazardRecognizer::
+resourcesCost(SUnit *SU) {
+  int Cost = 0;
+
+  const MCSchedClassDesc *SC = DAG->getSchedClass(SU);
+  if (!SC->isValid())
+    return 0;
+
+  // For a FPd op, either return min or max value as indicated by the
+  // distance to any prior FPd op.
+  if (SU->isUnbuffered)
+    Cost = (isFPdOpPreferred_distance(SU) ? INT_MIN : INT_MAX);
+  // For other instructions, give a cost to the use of the critical resource.
+  else if (CriticalResourceIdx != UINT_MAX) {
+    for (TargetSchedModel::ProcResIter
+           PI = SchedModel->getWriteProcResBegin(SC),
+           PE = SchedModel->getWriteProcResEnd(SC); PI != PE; ++PI)
+      if (PI->ProcResourceIdx == CriticalResourceIdx)
+        Cost = PI->Cycles;
+  }
+
+  return Cost;
+}
+