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, 375 insertions, 0 deletions

diff --git a/contrib/llvm/lib/LTO/LTOBackend.cpp b/contrib/llvm/lib/LTO/LTOBackend.cpp
new file mode 100644
index 0000000..809db80
--- /dev/null
+++ b/contrib/llvm/lib/LTO/LTOBackend.cpp
@@ -0,0 +1,375 @@
+//===-LTOBackend.cpp - LLVM Link Time Optimizer Backend -------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the "backend" phase of LTO, i.e. it performs
+// optimization and code generation on a loaded module. It is generally used
+// internally by the LTO class but can also be used independently, for example
+// to implement a standalone ThinLTO backend.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/LTO/LTOBackend.h"
+#include "llvm/Analysis/AliasAnalysis.h"
+#include "llvm/Analysis/CGSCCPassManager.h"
+#include "llvm/Analysis/TargetLibraryInfo.h"
+#include "llvm/Analysis/TargetTransformInfo.h"
+#include "llvm/Bitcode/BitcodeReader.h"
+#include "llvm/Bitcode/BitcodeWriter.h"
+#include "llvm/IR/LegacyPassManager.h"
+#include "llvm/IR/PassManager.h"
+#include "llvm/IR/Verifier.h"
+#include "llvm/LTO/LTO.h"
+#include "llvm/LTO/legacy/UpdateCompilerUsed.h"
+#include "llvm/MC/SubtargetFeature.h"
+#include "llvm/Passes/PassBuilder.h"
+#include "llvm/Support/Error.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/TargetRegistry.h"
+#include "llvm/Support/ThreadPool.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Transforms/IPO.h"
+#include "llvm/Transforms/IPO/PassManagerBuilder.h"
+#include "llvm/Transforms/Scalar/LoopPassManager.h"
+#include "llvm/Transforms/Utils/FunctionImportUtils.h"
+#include "llvm/Transforms/Utils/SplitModule.h"
+
+using namespace llvm;
+using namespace lto;
+
+LLVM_ATTRIBUTE_NORETURN static void reportOpenError(StringRef Path, Twine Msg) {
+  errs() << "failed to open " << Path << ": " << Msg << '\n';
+  errs().flush();
+  exit(1);
+}
+
+Error Config::addSaveTemps(std::string OutputFileName,
+                           bool UseInputModulePath) {
+  ShouldDiscardValueNames = false;
+
+  std::error_code EC;
+  ResolutionFile = llvm::make_unique<raw_fd_ostream>(
+      OutputFileName + "resolution.txt", EC, sys::fs::OpenFlags::F_Text);
+  if (EC)
+    return errorCodeToError(EC);
+
+  auto setHook = [&](std::string PathSuffix, ModuleHookFn &Hook) {
+    // Keep track of the hook provided by the linker, which also needs to run.
+    ModuleHookFn LinkerHook = Hook;
+    Hook = [=](unsigned Task, const Module &M) {
+      // If the linker's hook returned false, we need to pass that result
+      // through.
+      if (LinkerHook && !LinkerHook(Task, M))
+        return false;
+
+      std::string PathPrefix;
+      // If this is the combined module (not a ThinLTO backend compile) or the
+      // user hasn't requested using the input module's path, emit to a file
+      // named from the provided OutputFileName with the Task ID appended.
+      if (M.getModuleIdentifier() == "ld-temp.o" || !UseInputModulePath) {
+        PathPrefix = OutputFileName + utostr(Task);
+      } else
+        PathPrefix = M.getModuleIdentifier();
+      std::string Path = PathPrefix + "." + PathSuffix + ".bc";
+      std::error_code EC;
+      raw_fd_ostream OS(Path, EC, sys::fs::OpenFlags::F_None);
+      // Because -save-temps is a debugging feature, we report the error
+      // directly and exit.
+      if (EC)
+        reportOpenError(Path, EC.message());
+      WriteBitcodeToFile(&M, OS, /*ShouldPreserveUseListOrder=*/false);
+      return true;
+    };
+  };
+
+  setHook("0.preopt", PreOptModuleHook);
+  setHook("1.promote", PostPromoteModuleHook);
+  setHook("2.internalize", PostInternalizeModuleHook);
+  setHook("3.import", PostImportModuleHook);
+  setHook("4.opt", PostOptModuleHook);
+  setHook("5.precodegen", PreCodeGenModuleHook);
+
+  CombinedIndexHook = [=](const ModuleSummaryIndex &Index) {
+    std::string Path = OutputFileName + "index.bc";
+    std::error_code EC;
+    raw_fd_ostream OS(Path, EC, sys::fs::OpenFlags::F_None);
+    // Because -save-temps is a debugging feature, we report the error
+    // directly and exit.
+    if (EC)
+      reportOpenError(Path, EC.message());
+    WriteIndexToFile(Index, OS);
+    return true;
+  };
+
+  return Error::success();
+}
+
+namespace {
+
+std::unique_ptr<TargetMachine>
+createTargetMachine(Config &Conf, StringRef TheTriple,
+                    const Target *TheTarget) {
+  SubtargetFeatures Features;
+  Features.getDefaultSubtargetFeatures(Triple(TheTriple));
+  for (const std::string &A : Conf.MAttrs)
+    Features.AddFeature(A);
+
+  return std::unique_ptr<TargetMachine>(TheTarget->createTargetMachine(
+      TheTriple, Conf.CPU, Features.getString(), Conf.Options, Conf.RelocModel,
+      Conf.CodeModel, Conf.CGOptLevel));
+}
+
+static void runNewPMCustomPasses(Module &Mod, TargetMachine *TM,
+                                 std::string PipelineDesc,
+                                 std::string AAPipelineDesc,
+                                 bool DisableVerify) {
+  PassBuilder PB(TM);
+  AAManager AA;
+
+  // Parse a custom AA pipeline if asked to.
+  if (!AAPipelineDesc.empty())
+    if (!PB.parseAAPipeline(AA, AAPipelineDesc))
+      report_fatal_error("unable to parse AA pipeline description: " +
+                         AAPipelineDesc);
+
+  LoopAnalysisManager LAM;
+  FunctionAnalysisManager FAM;
+  CGSCCAnalysisManager CGAM;
+  ModuleAnalysisManager MAM;
+
+  // Register the AA manager first so that our version is the one used.
+  FAM.registerPass([&] { return std::move(AA); });
+
+  // Register all the basic analyses with the managers.
+  PB.registerModuleAnalyses(MAM);
+  PB.registerCGSCCAnalyses(CGAM);
+  PB.registerFunctionAnalyses(FAM);
+  PB.registerLoopAnalyses(LAM);
+  PB.crossRegisterProxies(LAM, FAM, CGAM, MAM);
+
+  ModulePassManager MPM;
+
+  // Always verify the input.
+  MPM.addPass(VerifierPass());
+
+  // Now, add all the passes we've been requested to.
+  if (!PB.parsePassPipeline(MPM, PipelineDesc))
+    report_fatal_error("unable to parse pass pipeline description: " +
+                       PipelineDesc);
+
+  if (!DisableVerify)
+    MPM.addPass(VerifierPass());
+  MPM.run(Mod, MAM);
+}
+
+static void runOldPMPasses(Config &Conf, Module &Mod, TargetMachine *TM,
+                           bool IsThinLTO) {
+  legacy::PassManager passes;
+  passes.add(createTargetTransformInfoWrapperPass(TM->getTargetIRAnalysis()));
+
+  PassManagerBuilder PMB;
+  PMB.LibraryInfo = new TargetLibraryInfoImpl(Triple(TM->getTargetTriple()));
+  PMB.Inliner = createFunctionInliningPass();
+  // Unconditionally verify input since it is not verified before this
+  // point and has unknown origin.
+  PMB.VerifyInput = true;
+  PMB.VerifyOutput = !Conf.DisableVerify;
+  PMB.LoopVectorize = true;
+  PMB.SLPVectorize = true;
+  PMB.OptLevel = Conf.OptLevel;
+  PMB.PGOSampleUse = Conf.SampleProfile;
+  if (IsThinLTO)
+    PMB.populateThinLTOPassManager(passes);
+  else
+    PMB.populateLTOPassManager(passes);
+  passes.run(Mod);
+}
+
+bool opt(Config &Conf, TargetMachine *TM, unsigned Task, Module &Mod,
+         bool IsThinLTO) {
+  if (Conf.OptPipeline.empty())
+    runOldPMPasses(Conf, Mod, TM, IsThinLTO);
+  else
+    runNewPMCustomPasses(Mod, TM, Conf.OptPipeline, Conf.AAPipeline,
+                         Conf.DisableVerify);
+  return !Conf.PostOptModuleHook || Conf.PostOptModuleHook(Task, Mod);
+}
+
+void codegen(Config &Conf, TargetMachine *TM, AddStreamFn AddStream,
+             unsigned Task, Module &Mod) {
+  if (Conf.PreCodeGenModuleHook && !Conf.PreCodeGenModuleHook(Task, Mod))
+    return;
+
+  auto Stream = AddStream(Task);
+  legacy::PassManager CodeGenPasses;
+  if (TM->addPassesToEmitFile(CodeGenPasses, *Stream->OS,
+                              TargetMachine::CGFT_ObjectFile))
+    report_fatal_error("Failed to setup codegen");
+  CodeGenPasses.run(Mod);
+}
+
+void splitCodeGen(Config &C, TargetMachine *TM, AddStreamFn AddStream,
+                  unsigned ParallelCodeGenParallelismLevel,
+                  std::unique_ptr<Module> Mod) {
+  ThreadPool CodegenThreadPool(ParallelCodeGenParallelismLevel);
+  unsigned ThreadCount = 0;
+  const Target *T = &TM->getTarget();
+
+  SplitModule(
+      std::move(Mod), ParallelCodeGenParallelismLevel,
+      [&](std::unique_ptr<Module> MPart) {
+        // We want to clone the module in a new context to multi-thread the
+        // codegen. We do it by serializing partition modules to bitcode
+        // (while still on the main thread, in order to avoid data races) and
+        // spinning up new threads which deserialize the partitions into
+        // separate contexts.
+        // FIXME: Provide a more direct way to do this in LLVM.
+        SmallString<0> BC;
+        raw_svector_ostream BCOS(BC);
+        WriteBitcodeToFile(MPart.get(), BCOS);
+
+        // Enqueue the task
+        CodegenThreadPool.async(
+            [&](const SmallString<0> &BC, unsigned ThreadId) {
+              LTOLLVMContext Ctx(C);
+              Expected<std::unique_ptr<Module>> MOrErr = parseBitcodeFile(
+                  MemoryBufferRef(StringRef(BC.data(), BC.size()), "ld-temp.o"),
+                  Ctx);
+              if (!MOrErr)
+                report_fatal_error("Failed to read bitcode");
+              std::unique_ptr<Module> MPartInCtx = std::move(MOrErr.get());
+
+              std::unique_ptr<TargetMachine> TM =
+                  createTargetMachine(C, MPartInCtx->getTargetTriple(), T);
+
+              codegen(C, TM.get(), AddStream, ThreadId, *MPartInCtx);
+            },
+            // Pass BC using std::move to ensure that it get moved rather than
+            // copied into the thread's context.
+            std::move(BC), ThreadCount++);
+      },
+      false);
+
+  // Because the inner lambda (which runs in a worker thread) captures our local
+  // variables, we need to wait for the worker threads to terminate before we
+  // can leave the function scope.
+  CodegenThreadPool.wait();
+}
+
+Expected<const Target *> initAndLookupTarget(Config &C, Module &Mod) {
+  if (!C.OverrideTriple.empty())
+    Mod.setTargetTriple(C.OverrideTriple);
+  else if (Mod.getTargetTriple().empty())
+    Mod.setTargetTriple(C.DefaultTriple);
+
+  std::string Msg;
+  const Target *T = TargetRegistry::lookupTarget(Mod.getTargetTriple(), Msg);
+  if (!T)
+    return make_error<StringError>(Msg, inconvertibleErrorCode());
+  return T;
+}
+
+}
+
+static void handleAsmUndefinedRefs(Module &Mod, TargetMachine &TM) {
+  // Collect the list of undefined symbols used in asm and update
+  // llvm.compiler.used to prevent optimization to drop these from the output.
+  StringSet<> AsmUndefinedRefs;
+  ModuleSymbolTable::CollectAsmSymbols(
+      Triple(Mod.getTargetTriple()), Mod.getModuleInlineAsm(),
+      [&AsmUndefinedRefs](StringRef Name, object::BasicSymbolRef::Flags Flags) {
+        if (Flags & object::BasicSymbolRef::SF_Undefined)
+          AsmUndefinedRefs.insert(Name);
+      });
+  updateCompilerUsed(Mod, TM, AsmUndefinedRefs);
+}
+
+Error lto::backend(Config &C, AddStreamFn AddStream,
+                   unsigned ParallelCodeGenParallelismLevel,
+                   std::unique_ptr<Module> Mod) {
+  Expected<const Target *> TOrErr = initAndLookupTarget(C, *Mod);
+  if (!TOrErr)
+    return TOrErr.takeError();
+
+  std::unique_ptr<TargetMachine> TM =
+      createTargetMachine(C, Mod->getTargetTriple(), *TOrErr);
+
+  handleAsmUndefinedRefs(*Mod, *TM);
+
+  if (!C.CodeGenOnly)
+    if (!opt(C, TM.get(), 0, *Mod, /*IsThinLTO=*/false))
+      return Error::success();
+
+  if (ParallelCodeGenParallelismLevel == 1) {
+    codegen(C, TM.get(), AddStream, 0, *Mod);
+  } else {
+    splitCodeGen(C, TM.get(), AddStream, ParallelCodeGenParallelismLevel,
+                 std::move(Mod));
+  }
+  return Error::success();
+}
+
+Error lto::thinBackend(Config &Conf, unsigned Task, AddStreamFn AddStream,
+                       Module &Mod, ModuleSummaryIndex &CombinedIndex,
+                       const FunctionImporter::ImportMapTy &ImportList,
+                       const GVSummaryMapTy &DefinedGlobals,
+                       MapVector<StringRef, BitcodeModule> &ModuleMap) {
+  Expected<const Target *> TOrErr = initAndLookupTarget(Conf, Mod);
+  if (!TOrErr)
+    return TOrErr.takeError();
+
+  std::unique_ptr<TargetMachine> TM =
+      createTargetMachine(Conf, Mod.getTargetTriple(), *TOrErr);
+
+  handleAsmUndefinedRefs(Mod, *TM);
+
+  if (Conf.CodeGenOnly) {
+    codegen(Conf, TM.get(), AddStream, Task, Mod);
+    return Error::success();
+  }
+
+  if (Conf.PreOptModuleHook && !Conf.PreOptModuleHook(Task, Mod))
+    return Error::success();
+
+  renameModuleForThinLTO(Mod, CombinedIndex);
+
+  thinLTOResolveWeakForLinkerModule(Mod, DefinedGlobals);
+
+  if (Conf.PostPromoteModuleHook && !Conf.PostPromoteModuleHook(Task, Mod))
+    return Error::success();
+
+  if (!DefinedGlobals.empty())
+    thinLTOInternalizeModule(Mod, DefinedGlobals);
+
+  if (Conf.PostInternalizeModuleHook &&
+      !Conf.PostInternalizeModuleHook(Task, Mod))
+    return Error::success();
+
+  auto ModuleLoader = [&](StringRef Identifier) {
+    assert(Mod.getContext().isODRUniquingDebugTypes() &&
+           "ODR Type uniquing should be enabled on the context");
+    auto I = ModuleMap.find(Identifier);
+    assert(I != ModuleMap.end());
+    return I->second.getLazyModule(Mod.getContext(),
+                                   /*ShouldLazyLoadMetadata=*/true,
+                                   /*IsImporting*/ true);
+  };
+
+  FunctionImporter Importer(CombinedIndex, ModuleLoader);
+  if (Error Err = Importer.importFunctions(Mod, ImportList).takeError())
+    return Err;
+
+  if (Conf.PostImportModuleHook && !Conf.PostImportModuleHook(Task, Mod))
+    return Error::success();
+
+  if (!opt(Conf, TM.get(), Task, Mod, /*IsThinLTO=*/true))
+    return Error::success();
+
+  codegen(Conf, TM.get(), AddStream, Task, Mod);
+  return Error::success();
+}