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, 304 insertions, 0 deletions

diff --git a/contrib/llvm/lib/Transforms/Scalar/LoopDataPrefetch.cpp b/contrib/llvm/lib/Transforms/Scalar/LoopDataPrefetch.cpp
new file mode 100644
index 0000000..66b59d2
--- /dev/null
+++ b/contrib/llvm/lib/Transforms/Scalar/LoopDataPrefetch.cpp
@@ -0,0 +1,304 @@
+//===-------- LoopDataPrefetch.cpp - Loop Data Prefetching Pass -----------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements a Loop Data Prefetching Pass.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "loop-data-prefetch"
+#include "llvm/Transforms/Scalar.h"
+#include "llvm/ADT/DepthFirstIterator.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/Analysis/AssumptionCache.h"
+#include "llvm/Analysis/CodeMetrics.h"
+#include "llvm/Analysis/InstructionSimplify.h"
+#include "llvm/Analysis/LoopInfo.h"
+#include "llvm/Analysis/ScalarEvolution.h"
+#include "llvm/Analysis/ScalarEvolutionAliasAnalysis.h"
+#include "llvm/Analysis/ScalarEvolutionExpander.h"
+#include "llvm/Analysis/ScalarEvolutionExpressions.h"
+#include "llvm/Analysis/TargetTransformInfo.h"
+#include "llvm/Analysis/ValueTracking.h"
+#include "llvm/IR/CFG.h"
+#include "llvm/IR/DiagnosticInfo.h"
+#include "llvm/IR/Dominators.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/IntrinsicInst.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Transforms/Utils/BasicBlockUtils.h"
+#include "llvm/Transforms/Utils/Local.h"
+#include "llvm/Transforms/Utils/ValueMapper.h"
+using namespace llvm;
+
+// By default, we limit this to creating 16 PHIs (which is a little over half
+// of the allocatable register set).
+static cl::opt<bool>
+PrefetchWrites("loop-prefetch-writes", cl::Hidden, cl::init(false),
+               cl::desc("Prefetch write addresses"));
+
+static cl::opt<unsigned>
+    PrefetchDistance("prefetch-distance",
+                     cl::desc("Number of instructions to prefetch ahead"),
+                     cl::Hidden);
+
+static cl::opt<unsigned>
+    MinPrefetchStride("min-prefetch-stride",
+                      cl::desc("Min stride to add prefetches"), cl::Hidden);
+
+static cl::opt<unsigned> MaxPrefetchIterationsAhead(
+    "max-prefetch-iters-ahead",
+    cl::desc("Max number of iterations to prefetch ahead"), cl::Hidden);
+
+STATISTIC(NumPrefetches, "Number of prefetches inserted");
+
+namespace llvm {
+  void initializeLoopDataPrefetchPass(PassRegistry&);
+}
+
+namespace {
+
+  class LoopDataPrefetch : public FunctionPass {
+  public:
+    static char ID; // Pass ID, replacement for typeid
+    LoopDataPrefetch() : FunctionPass(ID) {
+      initializeLoopDataPrefetchPass(*PassRegistry::getPassRegistry());
+    }
+
+    void getAnalysisUsage(AnalysisUsage &AU) const override {
+      AU.addRequired<AssumptionCacheTracker>();
+      AU.addPreserved<DominatorTreeWrapperPass>();
+      AU.addRequired<LoopInfoWrapperPass>();
+      AU.addPreserved<LoopInfoWrapperPass>();
+      AU.addRequired<ScalarEvolutionWrapperPass>();
+      // FIXME: For some reason, preserving SE here breaks LSR (even if
+      // this pass changes nothing).
+      // AU.addPreserved<ScalarEvolutionWrapperPass>();
+      AU.addRequired<TargetTransformInfoWrapperPass>();
+    }
+
+    bool runOnFunction(Function &F) override;
+
+  private:
+    bool runOnLoop(Loop *L);
+
+    /// \brief Check if the the stride of the accesses is large enough to
+    /// warrant a prefetch.
+    bool isStrideLargeEnough(const SCEVAddRecExpr *AR);
+
+    unsigned getMinPrefetchStride() {
+      if (MinPrefetchStride.getNumOccurrences() > 0)
+        return MinPrefetchStride;
+      return TTI->getMinPrefetchStride();
+    }
+
+    unsigned getPrefetchDistance() {
+      if (PrefetchDistance.getNumOccurrences() > 0)
+        return PrefetchDistance;
+      return TTI->getPrefetchDistance();
+    }
+
+    unsigned getMaxPrefetchIterationsAhead() {
+      if (MaxPrefetchIterationsAhead.getNumOccurrences() > 0)
+        return MaxPrefetchIterationsAhead;
+      return TTI->getMaxPrefetchIterationsAhead();
+    }
+
+    AssumptionCache *AC;
+    LoopInfo *LI;
+    ScalarEvolution *SE;
+    const TargetTransformInfo *TTI;
+    const DataLayout *DL;
+  };
+}
+
+char LoopDataPrefetch::ID = 0;
+INITIALIZE_PASS_BEGIN(LoopDataPrefetch, "loop-data-prefetch",
+                      "Loop Data Prefetch", false, false)
+INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
+INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass)
+INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass)
+INITIALIZE_PASS_DEPENDENCY(ScalarEvolutionWrapperPass)
+INITIALIZE_PASS_END(LoopDataPrefetch, "loop-data-prefetch",
+                    "Loop Data Prefetch", false, false)
+
+FunctionPass *llvm::createLoopDataPrefetchPass() { return new LoopDataPrefetch(); }
+
+bool LoopDataPrefetch::isStrideLargeEnough(const SCEVAddRecExpr *AR) {
+  unsigned TargetMinStride = getMinPrefetchStride();
+  // No need to check if any stride goes.
+  if (TargetMinStride <= 1)
+    return true;
+
+  const auto *ConstStride = dyn_cast<SCEVConstant>(AR->getStepRecurrence(*SE));
+  // If MinStride is set, don't prefetch unless we can ensure that stride is
+  // larger.
+  if (!ConstStride)
+    return false;
+
+  unsigned AbsStride = std::abs(ConstStride->getAPInt().getSExtValue());
+  return TargetMinStride <= AbsStride;
+}
+
+bool LoopDataPrefetch::runOnFunction(Function &F) {
+  if (skipFunction(F))
+    return false;
+
+  LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
+  SE = &getAnalysis<ScalarEvolutionWrapperPass>().getSE();
+  DL = &F.getParent()->getDataLayout();
+  AC = &getAnalysis<AssumptionCacheTracker>().getAssumptionCache(F);
+  TTI = &getAnalysis<TargetTransformInfoWrapperPass>().getTTI(F);
+
+  // If PrefetchDistance is not set, don't run the pass.  This gives an
+  // opportunity for targets to run this pass for selected subtargets only
+  // (whose TTI sets PrefetchDistance).
+  if (getPrefetchDistance() == 0)
+    return false;
+  assert(TTI->getCacheLineSize() && "Cache line size is not set for target");
+
+  bool MadeChange = false;
+
+  for (Loop *I : *LI)
+    for (auto L = df_begin(I), LE = df_end(I); L != LE; ++L)
+      MadeChange |= runOnLoop(*L);
+
+  return MadeChange;
+}
+
+bool LoopDataPrefetch::runOnLoop(Loop *L) {
+  bool MadeChange = false;
+
+  // Only prefetch in the inner-most loop
+  if (!L->empty())
+    return MadeChange;
+
+  SmallPtrSet<const Value *, 32> EphValues;
+  CodeMetrics::collectEphemeralValues(L, AC, EphValues);
+
+  // Calculate the number of iterations ahead to prefetch
+  CodeMetrics Metrics;
+  for (Loop::block_iterator I = L->block_begin(), IE = L->block_end();
+       I != IE; ++I) {
+
+    // If the loop already has prefetches, then assume that the user knows
+    // what they are doing and don't add any more.
+    for (BasicBlock::iterator J = (*I)->begin(), JE = (*I)->end();
+         J != JE; ++J)
+      if (CallInst *CI = dyn_cast<CallInst>(J))
+        if (Function *F = CI->getCalledFunction())
+          if (F->getIntrinsicID() == Intrinsic::prefetch)
+            return MadeChange;
+
+    Metrics.analyzeBasicBlock(*I, *TTI, EphValues);
+  }
+  unsigned LoopSize = Metrics.NumInsts;
+  if (!LoopSize)
+    LoopSize = 1;
+
+  unsigned ItersAhead = getPrefetchDistance() / LoopSize;
+  if (!ItersAhead)
+    ItersAhead = 1;
+
+  if (ItersAhead > getMaxPrefetchIterationsAhead())
+    return MadeChange;
+
+  Function *F = L->getHeader()->getParent();
+  DEBUG(dbgs() << "Prefetching " << ItersAhead
+               << " iterations ahead (loop size: " << LoopSize << ") in "
+               << F->getName() << ": " << *L);
+
+  SmallVector<std::pair<Instruction *, const SCEVAddRecExpr *>, 16> PrefLoads;
+  for (Loop::block_iterator I = L->block_begin(), IE = L->block_end();
+       I != IE; ++I) {
+    for (BasicBlock::iterator J = (*I)->begin(), JE = (*I)->end();
+        J != JE; ++J) {
+      Value *PtrValue;
+      Instruction *MemI;
+
+      if (LoadInst *LMemI = dyn_cast<LoadInst>(J)) {
+        MemI = LMemI;
+        PtrValue = LMemI->getPointerOperand();
+      } else if (StoreInst *SMemI = dyn_cast<StoreInst>(J)) {
+        if (!PrefetchWrites) continue;
+        MemI = SMemI;
+        PtrValue = SMemI->getPointerOperand();
+      } else continue;
+
+      unsigned PtrAddrSpace = PtrValue->getType()->getPointerAddressSpace();
+      if (PtrAddrSpace)
+        continue;
+
+      if (L->isLoopInvariant(PtrValue))
+        continue;
+
+      const SCEV *LSCEV = SE->getSCEV(PtrValue);
+      const SCEVAddRecExpr *LSCEVAddRec = dyn_cast<SCEVAddRecExpr>(LSCEV);
+      if (!LSCEVAddRec)
+        continue;
+
+      // Check if the the stride of the accesses is large enough to warrant a
+      // prefetch.
+      if (!isStrideLargeEnough(LSCEVAddRec))
+        continue;
+
+      // We don't want to double prefetch individual cache lines. If this load
+      // is known to be within one cache line of some other load that has
+      // already been prefetched, then don't prefetch this one as well.
+      bool DupPref = false;
+      for (const auto &PrefLoad : PrefLoads) {
+        const SCEV *PtrDiff = SE->getMinusSCEV(LSCEVAddRec, PrefLoad.second);
+        if (const SCEVConstant *ConstPtrDiff =
+            dyn_cast<SCEVConstant>(PtrDiff)) {
+          int64_t PD = std::abs(ConstPtrDiff->getValue()->getSExtValue());
+          if (PD < (int64_t) TTI->getCacheLineSize()) {
+            DupPref = true;
+            break;
+          }
+        }
+      }
+      if (DupPref)
+        continue;
+
+      const SCEV *NextLSCEV = SE->getAddExpr(LSCEVAddRec, SE->getMulExpr(
+        SE->getConstant(LSCEVAddRec->getType(), ItersAhead),
+        LSCEVAddRec->getStepRecurrence(*SE)));
+      if (!isSafeToExpand(NextLSCEV, *SE))
+        continue;
+
+      PrefLoads.push_back(std::make_pair(MemI, LSCEVAddRec));
+
+      Type *I8Ptr = Type::getInt8PtrTy((*I)->getContext(), PtrAddrSpace);
+      SCEVExpander SCEVE(*SE, J->getModule()->getDataLayout(), "prefaddr");
+      Value *PrefPtrValue = SCEVE.expandCodeFor(NextLSCEV, I8Ptr, MemI);
+
+      IRBuilder<> Builder(MemI);
+      Module *M = (*I)->getParent()->getParent();
+      Type *I32 = Type::getInt32Ty((*I)->getContext());
+      Value *PrefetchFunc = Intrinsic::getDeclaration(M, Intrinsic::prefetch);
+      Builder.CreateCall(
+          PrefetchFunc,
+          {PrefPtrValue,
+           ConstantInt::get(I32, MemI->mayReadFromMemory() ? 0 : 1),
+           ConstantInt::get(I32, 3), ConstantInt::get(I32, 1)});
+      ++NumPrefetches;
+      DEBUG(dbgs() << "  Access: " << *PtrValue << ", SCEV: " << *LSCEV
+                   << "\n");
+      emitOptimizationRemark(F->getContext(), DEBUG_TYPE, *F,
+                             MemI->getDebugLoc(), "prefetched memory access");
+
+
+      MadeChange = true;
+    }
+  }
+
+  return MadeChange;
+}
+