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, 189 insertions, 13 deletions

diff --git a/contrib/llvm/lib/Transforms/Utils/LoopVersioning.cpp b/contrib/llvm/lib/Transforms/Utils/LoopVersioning.cpp
index 9a2a06c..b3c6169 100644
--- a/contrib/llvm/lib/Transforms/Utils/LoopVersioning.cpp
+++ b/contrib/llvm/lib/Transforms/Utils/LoopVersioning.cpp
@@ -18,11 +18,18 @@
 #include "llvm/Analysis/LoopInfo.h"
 #include "llvm/Analysis/ScalarEvolutionExpander.h"
 #include "llvm/IR/Dominators.h"
+#include "llvm/IR/MDBuilder.h"
 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
 #include "llvm/Transforms/Utils/Cloning.h"
 
 using namespace llvm;
 
+static cl::opt<bool>
+    AnnotateNoAlias("loop-version-annotate-no-alias", cl::init(true),
+                    cl::Hidden,
+                    cl::desc("Add no-alias annotation for instructions that "
+                             "are disambiguated by memchecks"));
+
 LoopVersioning::LoopVersioning(const LoopAccessInfo &LAI, Loop *L, LoopInfo *LI,
                                DominatorTree *DT, ScalarEvolution *SE,
                                bool UseLAIChecks)
@@ -32,12 +39,12 @@ LoopVersioning::LoopVersioning(const LoopAccessInfo &LAI, Loop *L, LoopInfo *LI,
   assert(L->getLoopPreheader() && "No preheader");
   if (UseLAIChecks) {
     setAliasChecks(LAI.getRuntimePointerChecking()->getChecks());
-    setSCEVChecks(LAI.PSE.getUnionPredicate());
+    setSCEVChecks(LAI.getPSE().getUnionPredicate());
   }
 }
 
 void LoopVersioning::setAliasChecks(
-    const SmallVector<RuntimePointerChecking::PointerCheck, 4> Checks) {
+    SmallVector<RuntimePointerChecking::PointerCheck, 4> Checks) {
   AliasChecks = std::move(Checks);
 }
 
@@ -56,9 +63,8 @@ void LoopVersioning::versionLoop(
   BasicBlock *RuntimeCheckBB = VersionedLoop->getLoopPreheader();
   std::tie(FirstCheckInst, MemRuntimeCheck) =
       LAI.addRuntimeChecks(RuntimeCheckBB->getTerminator(), AliasChecks);
-  assert(MemRuntimeCheck && "called even though needsAnyChecking = false");
 
-  const SCEVUnionPredicate &Pred = LAI.PSE.getUnionPredicate();
+  const SCEVUnionPredicate &Pred = LAI.getPSE().getUnionPredicate();
   SCEVExpander Exp(*SE, RuntimeCheckBB->getModule()->getDataLayout(),
                    "scev.check");
   SCEVRuntimeCheck =
@@ -71,7 +77,7 @@ void LoopVersioning::versionLoop(
 
   if (MemRuntimeCheck && SCEVRuntimeCheck) {
     RuntimeCheck = BinaryOperator::Create(Instruction::Or, MemRuntimeCheck,
-                                          SCEVRuntimeCheck, "ldist.safe");
+                                          SCEVRuntimeCheck, "lver.safe");
     if (auto *I = dyn_cast<Instruction>(RuntimeCheck))
       I->insertBefore(RuntimeCheckBB->getTerminator());
   } else
@@ -119,16 +125,14 @@ void LoopVersioning::addPHINodes(
     const SmallVectorImpl<Instruction *> &DefsUsedOutside) {
   BasicBlock *PHIBlock = VersionedLoop->getExitBlock();
   assert(PHIBlock && "No single successor to loop exit block");
+  PHINode *PN;
 
+  // First add a single-operand PHI for each DefsUsedOutside if one does not
+  // exists yet.
   for (auto *Inst : DefsUsedOutside) {
-    auto *NonVersionedLoopInst = cast<Instruction>(VMap[Inst]);
-    PHINode *PN;
-
-    // First see if we have a single-operand PHI with the value defined by the
+    // See if we have a single-operand PHI with the value defined by the
     // original loop.
     for (auto I = PHIBlock->begin(); (PN = dyn_cast<PHINode>(I)); ++I) {
-      assert(PN->getNumOperands() == 1 &&
-             "Exit block should only have on predecessor");
       if (PN->getIncomingValue(0) == Inst)
         break;
     }
@@ -141,7 +145,179 @@ void LoopVersioning::addPHINodes(
           User->replaceUsesOfWith(Inst, PN);
       PN->addIncoming(Inst, VersionedLoop->getExitingBlock());
     }
-    // Add the new incoming value from the non-versioned loop.
-    PN->addIncoming(NonVersionedLoopInst, NonVersionedLoop->getExitingBlock());
   }
+
+  // Then for each PHI add the operand for the edge from the cloned loop.
+  for (auto I = PHIBlock->begin(); (PN = dyn_cast<PHINode>(I)); ++I) {
+    assert(PN->getNumOperands() == 1 &&
+           "Exit block should only have on predecessor");
+
+    // If the definition was cloned used that otherwise use the same value.
+    Value *ClonedValue = PN->getIncomingValue(0);
+    auto Mapped = VMap.find(ClonedValue);
+    if (Mapped != VMap.end())
+      ClonedValue = Mapped->second;
+
+    PN->addIncoming(ClonedValue, NonVersionedLoop->getExitingBlock());
+  }
+}
+
+void LoopVersioning::prepareNoAliasMetadata() {
+  // We need to turn the no-alias relation between pointer checking groups into
+  // no-aliasing annotations between instructions.
+  //
+  // We accomplish this by mapping each pointer checking group (a set of
+  // pointers memchecked together) to an alias scope and then also mapping each
+  // group to the list of scopes it can't alias.
+
+  const RuntimePointerChecking *RtPtrChecking = LAI.getRuntimePointerChecking();
+  LLVMContext &Context = VersionedLoop->getHeader()->getContext();
+
+  // First allocate an aliasing scope for each pointer checking group.
+  //
+  // While traversing through the checking groups in the loop, also create a
+  // reverse map from pointers to the pointer checking group they were assigned
+  // to.
+  MDBuilder MDB(Context);
+  MDNode *Domain = MDB.createAnonymousAliasScopeDomain("LVerDomain");
+
+  for (const auto &Group : RtPtrChecking->CheckingGroups) {
+    GroupToScope[&Group] = MDB.createAnonymousAliasScope(Domain);
+
+    for (unsigned PtrIdx : Group.Members)
+      PtrToGroup[RtPtrChecking->getPointerInfo(PtrIdx).PointerValue] = &Group;
+  }
+
+  // Go through the checks and for each pointer group, collect the scopes for
+  // each non-aliasing pointer group.
+  DenseMap<const RuntimePointerChecking::CheckingPtrGroup *,
+           SmallVector<Metadata *, 4>>
+      GroupToNonAliasingScopes;
+
+  for (const auto &Check : AliasChecks)
+    GroupToNonAliasingScopes[Check.first].push_back(GroupToScope[Check.second]);
+
+  // Finally, transform the above to actually map to scope list which is what
+  // the metadata uses.
+
+  for (auto Pair : GroupToNonAliasingScopes)
+    GroupToNonAliasingScopeList[Pair.first] = MDNode::get(Context, Pair.second);
+}
+
+void LoopVersioning::annotateLoopWithNoAlias() {
+  if (!AnnotateNoAlias)
+    return;
+
+  // First prepare the maps.
+  prepareNoAliasMetadata();
+
+  // Add the scope and no-alias metadata to the instructions.
+  for (Instruction *I : LAI.getDepChecker().getMemoryInstructions()) {
+    annotateInstWithNoAlias(I);
+  }
+}
+
+void LoopVersioning::annotateInstWithNoAlias(Instruction *VersionedInst,
+                                             const Instruction *OrigInst) {
+  if (!AnnotateNoAlias)
+    return;
+
+  LLVMContext &Context = VersionedLoop->getHeader()->getContext();
+  const Value *Ptr = isa<LoadInst>(OrigInst)
+                         ? cast<LoadInst>(OrigInst)->getPointerOperand()
+                         : cast<StoreInst>(OrigInst)->getPointerOperand();
+
+  // Find the group for the pointer and then add the scope metadata.
+  auto Group = PtrToGroup.find(Ptr);
+  if (Group != PtrToGroup.end()) {
+    VersionedInst->setMetadata(
+        LLVMContext::MD_alias_scope,
+        MDNode::concatenate(
+            VersionedInst->getMetadata(LLVMContext::MD_alias_scope),
+            MDNode::get(Context, GroupToScope[Group->second])));
+
+    // Add the no-alias metadata.
+    auto NonAliasingScopeList = GroupToNonAliasingScopeList.find(Group->second);
+    if (NonAliasingScopeList != GroupToNonAliasingScopeList.end())
+      VersionedInst->setMetadata(
+          LLVMContext::MD_noalias,
+          MDNode::concatenate(
+              VersionedInst->getMetadata(LLVMContext::MD_noalias),
+              NonAliasingScopeList->second));
+  }
+}
+
+namespace {
+/// \brief Also expose this is a pass.  Currently this is only used for
+/// unit-testing.  It adds all memchecks necessary to remove all may-aliasing
+/// array accesses from the loop.
+class LoopVersioningPass : public FunctionPass {
+public:
+  LoopVersioningPass() : FunctionPass(ID) {
+    initializeLoopVersioningPassPass(*PassRegistry::getPassRegistry());
+  }
+
+  bool runOnFunction(Function &F) override {
+    auto *LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
+    auto *LAA = &getAnalysis<LoopAccessLegacyAnalysis>();
+    auto *DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
+    auto *SE = &getAnalysis<ScalarEvolutionWrapperPass>().getSE();
+
+    // Build up a worklist of inner-loops to version. This is necessary as the
+    // act of versioning a loop creates new loops and can invalidate iterators
+    // across the loops.
+    SmallVector<Loop *, 8> Worklist;
+
+    for (Loop *TopLevelLoop : *LI)
+      for (Loop *L : depth_first(TopLevelLoop))
+        // We only handle inner-most loops.
+        if (L->empty())
+          Worklist.push_back(L);
+
+    // Now walk the identified inner loops.
+    bool Changed = false;
+    for (Loop *L : Worklist) {
+      const LoopAccessInfo &LAI = LAA->getInfo(L);
+      if (LAI.getNumRuntimePointerChecks() ||
+          !LAI.getPSE().getUnionPredicate().isAlwaysTrue()) {
+        LoopVersioning LVer(LAI, L, LI, DT, SE);
+        LVer.versionLoop();
+        LVer.annotateLoopWithNoAlias();
+        Changed = true;
+      }
+    }
+
+    return Changed;
+  }
+
+  void getAnalysisUsage(AnalysisUsage &AU) const override {
+    AU.addRequired<LoopInfoWrapperPass>();
+    AU.addPreserved<LoopInfoWrapperPass>();
+    AU.addRequired<LoopAccessLegacyAnalysis>();
+    AU.addRequired<DominatorTreeWrapperPass>();
+    AU.addPreserved<DominatorTreeWrapperPass>();
+    AU.addRequired<ScalarEvolutionWrapperPass>();
+  }
+
+  static char ID;
+};
+}
+
+#define LVER_OPTION "loop-versioning"
+#define DEBUG_TYPE LVER_OPTION
+
+char LoopVersioningPass::ID;
+static const char LVer_name[] = "Loop Versioning";
+
+INITIALIZE_PASS_BEGIN(LoopVersioningPass, LVER_OPTION, LVer_name, false, false)
+INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass)
+INITIALIZE_PASS_DEPENDENCY(LoopAccessLegacyAnalysis)
+INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
+INITIALIZE_PASS_DEPENDENCY(ScalarEvolutionWrapperPass)
+INITIALIZE_PASS_END(LoopVersioningPass, LVER_OPTION, LVer_name, false, false)
+
+namespace llvm {
+FunctionPass *createLoopVersioningPass() {
+  return new LoopVersioningPass();
+}
 }