Update llvm and clang to release_38 branch r258549.

3 files changed, 555 insertions, 33 deletions

diff --git a/contrib/llvm/lib/Transforms/Utils/InlineFunction.cpp b/contrib/llvm/lib/Transforms/Utils/InlineFunction.cpp
index 1457411..79282a2 100644
--- a/contrib/llvm/lib/Transforms/Utils/InlineFunction.cpp
+++ b/contrib/llvm/lib/Transforms/Utils/InlineFunction.cpp
@@ -179,13 +179,244 @@ void LandingPadInliningInfo::forwardResume(
   RI->eraseFromParent();
 }
 
+/// Helper for getUnwindDestToken/getUnwindDestTokenHelper.
+static Value *getParentPad(Value *EHPad) {
+  if (auto *FPI = dyn_cast<FuncletPadInst>(EHPad))
+    return FPI->getParentPad();
+  return cast<CatchSwitchInst>(EHPad)->getParentPad();
+}
+
+typedef DenseMap<Instruction *, Value *> UnwindDestMemoTy;
+
+/// Helper for getUnwindDestToken that does the descendant-ward part of
+/// the search.
+static Value *getUnwindDestTokenHelper(Instruction *EHPad,
+                                       UnwindDestMemoTy &MemoMap) {
+  SmallVector<Instruction *, 8> Worklist(1, EHPad);
+
+  while (!Worklist.empty()) {
+    Instruction *CurrentPad = Worklist.pop_back_val();
+    // We only put pads on the worklist that aren't in the MemoMap.  When
+    // we find an unwind dest for a pad we may update its ancestors, but
+    // the queue only ever contains uncles/great-uncles/etc. of CurrentPad,
+    // so they should never get updated while queued on the worklist.
+    assert(!MemoMap.count(CurrentPad));
+    Value *UnwindDestToken = nullptr;
+    if (auto *CatchSwitch = dyn_cast<CatchSwitchInst>(CurrentPad)) {
+      if (CatchSwitch->hasUnwindDest()) {
+        UnwindDestToken = CatchSwitch->getUnwindDest()->getFirstNonPHI();
+      } else {
+        // Catchswitch doesn't have a 'nounwind' variant, and one might be
+        // annotated as "unwinds to caller" when really it's nounwind (see
+        // e.g. SimplifyCFGOpt::SimplifyUnreachable), so we can't infer the
+        // parent's unwind dest from this.  We can check its catchpads'
+        // descendants, since they might include a cleanuppad with an
+        // "unwinds to caller" cleanupret, which can be trusted.
+        for (auto HI = CatchSwitch->handler_begin(),
+                  HE = CatchSwitch->handler_end();
+             HI != HE && !UnwindDestToken; ++HI) {
+          BasicBlock *HandlerBlock = *HI;
+          auto *CatchPad = cast<CatchPadInst>(HandlerBlock->getFirstNonPHI());
+          for (User *Child : CatchPad->users()) {
+            // Intentionally ignore invokes here -- since the catchswitch is
+            // marked "unwind to caller", it would be a verifier error if it
+            // contained an invoke which unwinds out of it, so any invoke we'd
+            // encounter must unwind to some child of the catch.
+            if (!isa<CleanupPadInst>(Child) && !isa<CatchSwitchInst>(Child))
+              continue;
+
+            Instruction *ChildPad = cast<Instruction>(Child);
+            auto Memo = MemoMap.find(ChildPad);
+            if (Memo == MemoMap.end()) {
+              // Haven't figure out this child pad yet; queue it.
+              Worklist.push_back(ChildPad);
+              continue;
+            }
+            // We've already checked this child, but might have found that
+            // it offers no proof either way.
+            Value *ChildUnwindDestToken = Memo->second;
+            if (!ChildUnwindDestToken)
+              continue;
+            // We already know the child's unwind dest, which can either
+            // be ConstantTokenNone to indicate unwind to caller, or can
+            // be another child of the catchpad.  Only the former indicates
+            // the unwind dest of the catchswitch.
+            if (isa<ConstantTokenNone>(ChildUnwindDestToken)) {
+              UnwindDestToken = ChildUnwindDestToken;
+              break;
+            }
+            assert(getParentPad(ChildUnwindDestToken) == CatchPad);
+          }
+        }
+      }
+    } else {
+      auto *CleanupPad = cast<CleanupPadInst>(CurrentPad);
+      for (User *U : CleanupPad->users()) {
+        if (auto *CleanupRet = dyn_cast<CleanupReturnInst>(U)) {
+          if (BasicBlock *RetUnwindDest = CleanupRet->getUnwindDest())
+            UnwindDestToken = RetUnwindDest->getFirstNonPHI();
+          else
+            UnwindDestToken = ConstantTokenNone::get(CleanupPad->getContext());
+          break;
+        }
+        Value *ChildUnwindDestToken;
+        if (auto *Invoke = dyn_cast<InvokeInst>(U)) {
+          ChildUnwindDestToken = Invoke->getUnwindDest()->getFirstNonPHI();
+        } else if (isa<CleanupPadInst>(U) || isa<CatchSwitchInst>(U)) {
+          Instruction *ChildPad = cast<Instruction>(U);
+          auto Memo = MemoMap.find(ChildPad);
+          if (Memo == MemoMap.end()) {
+            // Haven't resolved this child yet; queue it and keep searching.
+            Worklist.push_back(ChildPad);
+            continue;
+          }
+          // We've checked this child, but still need to ignore it if it
+          // had no proof either way.
+          ChildUnwindDestToken = Memo->second;
+          if (!ChildUnwindDestToken)
+            continue;
+        } else {
+          // Not a relevant user of the cleanuppad
+          continue;
+        }
+        // In a well-formed program, the child/invoke must either unwind to
+        // an(other) child of the cleanup, or exit the cleanup.  In the
+        // first case, continue searching.
+        if (isa<Instruction>(ChildUnwindDestToken) &&
+            getParentPad(ChildUnwindDestToken) == CleanupPad)
+          continue;
+        UnwindDestToken = ChildUnwindDestToken;
+        break;
+      }
+    }
+    // If we haven't found an unwind dest for CurrentPad, we may have queued its
+    // children, so move on to the next in the worklist.
+    if (!UnwindDestToken)
+      continue;
+
+    // Now we know that CurrentPad unwinds to UnwindDestToken.  It also exits
+    // any ancestors of CurrentPad up to but not including UnwindDestToken's
+    // parent pad.  Record this in the memo map, and check to see if the
+    // original EHPad being queried is one of the ones exited.
+    Value *UnwindParent;
+    if (auto *UnwindPad = dyn_cast<Instruction>(UnwindDestToken))
+      UnwindParent = getParentPad(UnwindPad);
+    else
+      UnwindParent = nullptr;
+    bool ExitedOriginalPad = false;
+    for (Instruction *ExitedPad = CurrentPad;
+         ExitedPad && ExitedPad != UnwindParent;
+         ExitedPad = dyn_cast<Instruction>(getParentPad(ExitedPad))) {
+      // Skip over catchpads since they just follow their catchswitches.
+      if (isa<CatchPadInst>(ExitedPad))
+        continue;
+      MemoMap[ExitedPad] = UnwindDestToken;
+      ExitedOriginalPad |= (ExitedPad == EHPad);
+    }
+
+    if (ExitedOriginalPad)
+      return UnwindDestToken;
+
+    // Continue the search.
+  }
+
+  // No definitive information is contained within this funclet.
+  return nullptr;
+}
+
+/// Given an EH pad, find where it unwinds.  If it unwinds to an EH pad,
+/// return that pad instruction.  If it unwinds to caller, return
+/// ConstantTokenNone.  If it does not have a definitive unwind destination,
+/// return nullptr.
+///
+/// This routine gets invoked for calls in funclets in inlinees when inlining
+/// an invoke.  Since many funclets don't have calls inside them, it's queried
+/// on-demand rather than building a map of pads to unwind dests up front.
+/// Determining a funclet's unwind dest may require recursively searching its
+/// descendants, and also ancestors and cousins if the descendants don't provide
+/// an answer.  Since most funclets will have their unwind dest immediately
+/// available as the unwind dest of a catchswitch or cleanupret, this routine
+/// searches top-down from the given pad and then up. To avoid worst-case
+/// quadratic run-time given that approach, it uses a memo map to avoid
+/// re-processing funclet trees.  The callers that rewrite the IR as they go
+/// take advantage of this, for correctness, by checking/forcing rewritten
+/// pads' entries to match the original callee view.
+static Value *getUnwindDestToken(Instruction *EHPad,
+                                 UnwindDestMemoTy &MemoMap) {
+  // Catchpads unwind to the same place as their catchswitch;
+  // redirct any queries on catchpads so the code below can
+  // deal with just catchswitches and cleanuppads.
+  if (auto *CPI = dyn_cast<CatchPadInst>(EHPad))
+    EHPad = CPI->getCatchSwitch();
+
+  // Check if we've already determined the unwind dest for this pad.
+  auto Memo = MemoMap.find(EHPad);
+  if (Memo != MemoMap.end())
+    return Memo->second;
+
+  // Search EHPad and, if necessary, its descendants.
+  Value *UnwindDestToken = getUnwindDestTokenHelper(EHPad, MemoMap);
+  assert((UnwindDestToken == nullptr) != (MemoMap.count(EHPad) != 0));
+  if (UnwindDestToken)
+    return UnwindDestToken;
+
+  // No information is available for this EHPad from itself or any of its
+  // descendants.  An unwind all the way out to a pad in the caller would
+  // need also to agree with the unwind dest of the parent funclet, so
+  // search up the chain to try to find a funclet with information.  Put
+  // null entries in the memo map to avoid re-processing as we go up.
+  MemoMap[EHPad] = nullptr;
+  Instruction *LastUselessPad = EHPad;
+  Value *AncestorToken;
+  for (AncestorToken = getParentPad(EHPad);
+       auto *AncestorPad = dyn_cast<Instruction>(AncestorToken);
+       AncestorToken = getParentPad(AncestorToken)) {
+    // Skip over catchpads since they just follow their catchswitches.
+    if (isa<CatchPadInst>(AncestorPad))
+      continue;
+    assert(!MemoMap.count(AncestorPad) || MemoMap[AncestorPad]);
+    auto AncestorMemo = MemoMap.find(AncestorPad);
+    if (AncestorMemo == MemoMap.end()) {
+      UnwindDestToken = getUnwindDestTokenHelper(AncestorPad, MemoMap);
+    } else {
+      UnwindDestToken = AncestorMemo->second;
+    }
+    if (UnwindDestToken)
+      break;
+    LastUselessPad = AncestorPad;
+  }
+
+  // Since the whole tree under LastUselessPad has no information, it all must
+  // match UnwindDestToken; record that to avoid repeating the search.
+  SmallVector<Instruction *, 8> Worklist(1, LastUselessPad);
+  while (!Worklist.empty()) {
+    Instruction *UselessPad = Worklist.pop_back_val();
+    assert(!MemoMap.count(UselessPad) || MemoMap[UselessPad] == nullptr);
+    MemoMap[UselessPad] = UnwindDestToken;
+    if (auto *CatchSwitch = dyn_cast<CatchSwitchInst>(UselessPad)) {
+      for (BasicBlock *HandlerBlock : CatchSwitch->handlers())
+        for (User *U : HandlerBlock->getFirstNonPHI()->users())
+          if (isa<CatchSwitchInst>(U) || isa<CleanupPadInst>(U))
+            Worklist.push_back(cast<Instruction>(U));
+    } else {
+      assert(isa<CleanupPadInst>(UselessPad));
+      for (User *U : UselessPad->users())
+        if (isa<CatchSwitchInst>(U) || isa<CleanupPadInst>(U))
+          Worklist.push_back(cast<Instruction>(U));
+    }
+  }
+
+  return UnwindDestToken;
+}
+
 /// When we inline a basic block into an invoke,
 /// we have to turn all of the calls that can throw into invokes.
 /// This function analyze BB to see if there are any calls, and if so,
 /// it rewrites them to be invokes that jump to InvokeDest and fills in the PHI
 /// nodes in that block with the values specified in InvokeDestPHIValues.
-static BasicBlock *
-HandleCallsInBlockInlinedThroughInvoke(BasicBlock *BB, BasicBlock *UnwindEdge) {
+static BasicBlock *HandleCallsInBlockInlinedThroughInvoke(
+    BasicBlock *BB, BasicBlock *UnwindEdge,
+    UnwindDestMemoTy *FuncletUnwindMap = nullptr) {
   for (BasicBlock::iterator BBI = BB->begin(), E = BB->end(); BBI != E; ) {
     Instruction *I = &*BBI++;
 
@@ -196,6 +427,31 @@ HandleCallsInBlockInlinedThroughInvoke(BasicBlock *BB, BasicBlock *UnwindEdge) {
     if (!CI || CI->doesNotThrow() || isa<InlineAsm>(CI->getCalledValue()))
       continue;
 
+    if (auto FuncletBundle = CI->getOperandBundle(LLVMContext::OB_funclet)) {
+      // This call is nested inside a funclet.  If that funclet has an unwind
+      // destination within the inlinee, then unwinding out of this call would
+      // be UB.  Rewriting this call to an invoke which targets the inlined
+      // invoke's unwind dest would give the call's parent funclet multiple
+      // unwind destinations, which is something that subsequent EH table
+      // generation can't handle and that the veirifer rejects.  So when we
+      // see such a call, leave it as a call.
+      auto *FuncletPad = cast<Instruction>(FuncletBundle->Inputs[0]);
+      Value *UnwindDestToken =
+          getUnwindDestToken(FuncletPad, *FuncletUnwindMap);
+      if (UnwindDestToken && !isa<ConstantTokenNone>(UnwindDestToken))
+        continue;
+#ifndef NDEBUG
+      Instruction *MemoKey;
+      if (auto *CatchPad = dyn_cast<CatchPadInst>(FuncletPad))
+        MemoKey = CatchPad->getCatchSwitch();
+      else
+        MemoKey = FuncletPad;
+      assert(FuncletUnwindMap->count(MemoKey) &&
+             (*FuncletUnwindMap)[MemoKey] == UnwindDestToken &&
+             "must get memoized to avoid confusing later searches");
+#endif // NDEBUG
+    }
+
     // Convert this function call into an invoke instruction.  First, split the
     // basic block.
     BasicBlock *Split =
@@ -328,13 +584,23 @@ static void HandleInlinedEHPad(InvokeInst *II, BasicBlock *FirstNewBlock,
 
   // This connects all the instructions which 'unwind to caller' to the invoke
   // destination.
+  UnwindDestMemoTy FuncletUnwindMap;
   for (Function::iterator BB = FirstNewBlock->getIterator(), E = Caller->end();
        BB != E; ++BB) {
     if (auto *CRI = dyn_cast<CleanupReturnInst>(BB->getTerminator())) {
       if (CRI->unwindsToCaller()) {
-        CleanupReturnInst::Create(CRI->getCleanupPad(), UnwindDest, CRI);
+        auto *CleanupPad = CRI->getCleanupPad();
+        CleanupReturnInst::Create(CleanupPad, UnwindDest, CRI);
         CRI->eraseFromParent();
         UpdatePHINodes(&*BB);
+        // Finding a cleanupret with an unwind destination would confuse
+        // subsequent calls to getUnwindDestToken, so map the cleanuppad
+        // to short-circuit any such calls and recognize this as an "unwind
+        // to caller" cleanup.
+        assert(!FuncletUnwindMap.count(CleanupPad) ||
+               isa<ConstantTokenNone>(FuncletUnwindMap[CleanupPad]));
+        FuncletUnwindMap[CleanupPad] =
+            ConstantTokenNone::get(Caller->getContext());
       }
     }
 
@@ -345,12 +611,41 @@ static void HandleInlinedEHPad(InvokeInst *II, BasicBlock *FirstNewBlock,
     Instruction *Replacement = nullptr;
     if (auto *CatchSwitch = dyn_cast<CatchSwitchInst>(I)) {
       if (CatchSwitch->unwindsToCaller()) {
+        Value *UnwindDestToken;
+        if (auto *ParentPad =
+                dyn_cast<Instruction>(CatchSwitch->getParentPad())) {
+          // This catchswitch is nested inside another funclet.  If that
+          // funclet has an unwind destination within the inlinee, then
+          // unwinding out of this catchswitch would be UB.  Rewriting this
+          // catchswitch to unwind to the inlined invoke's unwind dest would
+          // give the parent funclet multiple unwind destinations, which is
+          // something that subsequent EH table generation can't handle and
+          // that the veirifer rejects.  So when we see such a call, leave it
+          // as "unwind to caller".
+          UnwindDestToken = getUnwindDestToken(ParentPad, FuncletUnwindMap);
+          if (UnwindDestToken && !isa<ConstantTokenNone>(UnwindDestToken))
+            continue;
+        } else {
+          // This catchswitch has no parent to inherit constraints from, and
+          // none of its descendants can have an unwind edge that exits it and
+          // targets another funclet in the inlinee.  It may or may not have a
+          // descendant that definitively has an unwind to caller.  In either
+          // case, we'll have to assume that any unwinds out of it may need to
+          // be routed to the caller, so treat it as though it has a definitive
+          // unwind to caller.
+          UnwindDestToken = ConstantTokenNone::get(Caller->getContext());
+        }
         auto *NewCatchSwitch = CatchSwitchInst::Create(
             CatchSwitch->getParentPad(), UnwindDest,
             CatchSwitch->getNumHandlers(), CatchSwitch->getName(),
             CatchSwitch);
         for (BasicBlock *PadBB : CatchSwitch->handlers())
           NewCatchSwitch->addHandler(PadBB);
+        // Propagate info for the old catchswitch over to the new one in
+        // the unwind map.  This also serves to short-circuit any subsequent
+        // checks for the unwind dest of this catchswitch, which would get
+        // confused if they found the outer handler in the callee.
+        FuncletUnwindMap[NewCatchSwitch] = UnwindDestToken;
         Replacement = NewCatchSwitch;
       }
     } else if (!isa<FuncletPadInst>(I)) {
@@ -369,8 +664,8 @@ static void HandleInlinedEHPad(InvokeInst *II, BasicBlock *FirstNewBlock,
     for (Function::iterator BB = FirstNewBlock->getIterator(),
                             E = Caller->end();
          BB != E; ++BB)
-      if (BasicBlock *NewBB =
-              HandleCallsInBlockInlinedThroughInvoke(&*BB, UnwindDest))
+      if (BasicBlock *NewBB = HandleCallsInBlockInlinedThroughInvoke(
+              &*BB, UnwindDest, &FuncletUnwindMap))
         // Update any PHI nodes in the exceptional block to indicate that there
         // is now a new entry in them.
         UpdatePHINodes(NewBB);
@@ -1415,6 +1710,20 @@ bool llvm::InlineFunction(CallSite CS, InlineFunctionInfo &IFI,
     }
   }
 
+  // If we are inlining for an invoke instruction, we must make sure to rewrite
+  // any call instructions into invoke instructions.  This is sensitive to which
+  // funclet pads were top-level in the inlinee, so must be done before
+  // rewriting the "parent pad" links.
+  if (auto *II = dyn_cast<InvokeInst>(TheCall)) {
+    BasicBlock *UnwindDest = II->getUnwindDest();
+    Instruction *FirstNonPHI = UnwindDest->getFirstNonPHI();
+    if (isa<LandingPadInst>(FirstNonPHI)) {
+      HandleInlinedLandingPad(II, &*FirstNewBlock, InlinedFunctionInfo);
+    } else {
+      HandleInlinedEHPad(II, &*FirstNewBlock, InlinedFunctionInfo);
+    }
+  }
+
   // Update the lexical scopes of the new funclets and callsites.
   // Anything that had 'none' as its parent is now nested inside the callsite's
   // EHPad.
@@ -1472,18 +1781,6 @@ bool llvm::InlineFunction(CallSite CS, InlineFunctionInfo &IFI,
     }
   }
 
-  // If we are inlining for an invoke instruction, we must make sure to rewrite
-  // any call instructions into invoke instructions.
-  if (auto *II = dyn_cast<InvokeInst>(TheCall)) {
-    BasicBlock *UnwindDest = II->getUnwindDest();
-    Instruction *FirstNonPHI = UnwindDest->getFirstNonPHI();
-    if (isa<LandingPadInst>(FirstNonPHI)) {
-      HandleInlinedLandingPad(II, &*FirstNewBlock, InlinedFunctionInfo);
-    } else {
-      HandleInlinedEHPad(II, &*FirstNewBlock, InlinedFunctionInfo);
-    }
-  }
-
   // Handle any inlined musttail call sites.  In order for a new call site to be
   // musttail, the source of the clone and the inlined call site must have been
   // musttail.  Therefore it's safe to return without merging control into the
diff --git a/contrib/llvm/lib/Transforms/Utils/Local.cpp b/contrib/llvm/lib/Transforms/Utils/Local.cpp
index 1cb65fc..abc9b65 100644
--- a/contrib/llvm/lib/Transforms/Utils/Local.cpp
+++ b/contrib/llvm/lib/Transforms/Utils/Local.cpp
@@ -1592,3 +1592,205 @@ bool llvm::callsGCLeafFunction(ImmutableCallSite CS) {
 
   return false;
 }
+
+/// A potential constituent of a bitreverse or bswap expression. See
+/// collectBitParts for a fuller explanation.
+struct BitPart {
+  BitPart(Value *P, unsigned BW) : Provider(P) {
+    Provenance.resize(BW);
+  }
+
+  /// The Value that this is a bitreverse/bswap of.
+  Value *Provider;
+  /// The "provenance" of each bit. Provenance[A] = B means that bit A
+  /// in Provider becomes bit B in the result of this expression.
+  SmallVector<int8_t, 32> Provenance; // int8_t means max size is i128.
+
+  enum { Unset = -1 };
+};
+
+/// Analyze the specified subexpression and see if it is capable of providing
+/// pieces of a bswap or bitreverse. The subexpression provides a potential
+/// piece of a bswap or bitreverse if it can be proven that each non-zero bit in
+/// the output of the expression came from a corresponding bit in some other
+/// value. This function is recursive, and the end result is a mapping of
+/// bitnumber to bitnumber. It is the caller's responsibility to validate that
+/// the bitnumber to bitnumber mapping is correct for a bswap or bitreverse.
+///
+/// For example, if the current subexpression if "(shl i32 %X, 24)" then we know
+/// that the expression deposits the low byte of %X into the high byte of the
+/// result and that all other bits are zero. This expression is accepted and a
+/// BitPart is returned with Provider set to %X and Provenance[24-31] set to
+/// [0-7].
+///
+/// To avoid revisiting values, the BitPart results are memoized into the
+/// provided map. To avoid unnecessary copying of BitParts, BitParts are
+/// constructed in-place in the \c BPS map. Because of this \c BPS needs to
+/// store BitParts objects, not pointers. As we need the concept of a nullptr
+/// BitParts (Value has been analyzed and the analysis failed), we an Optional
+/// type instead to provide the same functionality.
+///
+/// Because we pass around references into \c BPS, we must use a container that
+/// does not invalidate internal references (std::map instead of DenseMap).
+///
+static const Optional<BitPart> &
+collectBitParts(Value *V, bool MatchBSwaps, bool MatchBitReversals,
+                std::map<Value *, Optional<BitPart>> &BPS) {
+  auto I = BPS.find(V);
+  if (I != BPS.end())
+    return I->second;
+
+  auto &Result = BPS[V] = None;
+  auto BitWidth = cast<IntegerType>(V->getType())->getBitWidth();
+
+  if (Instruction *I = dyn_cast<Instruction>(V)) {
+    // If this is an or instruction, it may be an inner node of the bswap.
+    if (I->getOpcode() == Instruction::Or) {
+      auto &A = collectBitParts(I->getOperand(0), MatchBSwaps,
+                                MatchBitReversals, BPS);
+      auto &B = collectBitParts(I->getOperand(1), MatchBSwaps,
+                                MatchBitReversals, BPS);
+      if (!A || !B)
+        return Result;
+
+      // Try and merge the two together.
+      if (!A->Provider || A->Provider != B->Provider)
+        return Result;
+
+      Result = BitPart(A->Provider, BitWidth);
+      for (unsigned i = 0; i < A->Provenance.size(); ++i) {
+        if (A->Provenance[i] != BitPart::Unset &&
+            B->Provenance[i] != BitPart::Unset &&
+            A->Provenance[i] != B->Provenance[i])
+          return Result = None;
+
+        if (A->Provenance[i] == BitPart::Unset)
+          Result->Provenance[i] = B->Provenance[i];
+        else
+          Result->Provenance[i] = A->Provenance[i];
+      }
+
+      return Result;
+    }
+
+    // If this is a logical shift by a constant, recurse then shift the result.
+    if (I->isLogicalShift() && isa<ConstantInt>(I->getOperand(1))) {
+      unsigned BitShift =
+          cast<ConstantInt>(I->getOperand(1))->getLimitedValue(~0U);
+      // Ensure the shift amount is defined.
+      if (BitShift > BitWidth)
+        return Result;
+
+      auto &Res = collectBitParts(I->getOperand(0), MatchBSwaps,
+                                  MatchBitReversals, BPS);
+      if (!Res)
+        return Result;
+      Result = Res;
+
+      // Perform the "shift" on BitProvenance.
+      auto &P = Result->Provenance;
+      if (I->getOpcode() == Instruction::Shl) {
+        P.erase(std::prev(P.end(), BitShift), P.end());
+        P.insert(P.begin(), BitShift, BitPart::Unset);
+      } else {
+        P.erase(P.begin(), std::next(P.begin(), BitShift));
+        P.insert(P.end(), BitShift, BitPart::Unset);
+      }
+
+      return Result;
+    }
+
+    // If this is a logical 'and' with a mask that clears bits, recurse then
+    // unset the appropriate bits.
+    if (I->getOpcode() == Instruction::And &&
+        isa<ConstantInt>(I->getOperand(1))) {
+      APInt Bit(I->getType()->getPrimitiveSizeInBits(), 1);
+      const APInt &AndMask = cast<ConstantInt>(I->getOperand(1))->getValue();
+
+      // Check that the mask allows a multiple of 8 bits for a bswap, for an
+      // early exit.
+      unsigned NumMaskedBits = AndMask.countPopulation();
+      if (!MatchBitReversals && NumMaskedBits % 8 != 0)
+        return Result;
+      
+      auto &Res = collectBitParts(I->getOperand(0), MatchBSwaps,
+                                  MatchBitReversals, BPS);
+      if (!Res)
+        return Result;
+      Result = Res;
+
+      for (unsigned i = 0; i < BitWidth; ++i, Bit <<= 1)
+        // If the AndMask is zero for this bit, clear the bit.
+        if ((AndMask & Bit) == 0)
+          Result->Provenance[i] = BitPart::Unset;
+
+      return Result;
+    }
+  }
+
+  // Okay, we got to something that isn't a shift, 'or' or 'and'.  This must be
+  // the input value to the bswap/bitreverse.
+  Result = BitPart(V, BitWidth);
+  for (unsigned i = 0; i < BitWidth; ++i)
+    Result->Provenance[i] = i;
+  return Result;
+}
+
+static bool bitTransformIsCorrectForBSwap(unsigned From, unsigned To,
+                                          unsigned BitWidth) {
+  if (From % 8 != To % 8)
+    return false;
+  // Convert from bit indices to byte indices and check for a byte reversal.
+  From >>= 3;
+  To >>= 3;
+  BitWidth >>= 3;
+  return From == BitWidth - To - 1;
+}
+
+static bool bitTransformIsCorrectForBitReverse(unsigned From, unsigned To,
+                                               unsigned BitWidth) {
+  return From == BitWidth - To - 1;
+}
+
+/// Given an OR instruction, check to see if this is a bitreverse
+/// idiom. If so, insert the new intrinsic and return true.
+bool llvm::recognizeBitReverseOrBSwapIdiom(
+    Instruction *I, bool MatchBSwaps, bool MatchBitReversals,
+    SmallVectorImpl<Instruction *> &InsertedInsts) {
+  if (Operator::getOpcode(I) != Instruction::Or)
+    return false;
+  if (!MatchBSwaps && !MatchBitReversals)
+    return false;
+  IntegerType *ITy = dyn_cast<IntegerType>(I->getType());
+  if (!ITy || ITy->getBitWidth() > 128)
+    return false;   // Can't do vectors or integers > 128 bits.
+  unsigned BW = ITy->getBitWidth();
+
+  // Try to find all the pieces corresponding to the bswap.
+  std::map<Value *, Optional<BitPart>> BPS;
+  auto Res = collectBitParts(I, MatchBSwaps, MatchBitReversals, BPS);
+  if (!Res)
+    return false;
+  auto &BitProvenance = Res->Provenance;
+
+  // Now, is the bit permutation correct for a bswap or a bitreverse? We can
+  // only byteswap values with an even number of bytes.
+  bool OKForBSwap = BW % 16 == 0, OKForBitReverse = true;
+  for (unsigned i = 0; i < BW; ++i) {
+    OKForBSwap &= bitTransformIsCorrectForBSwap(BitProvenance[i], i, BW);
+    OKForBitReverse &=
+        bitTransformIsCorrectForBitReverse(BitProvenance[i], i, BW);
+  }
+
+  Intrinsic::ID Intrin;
+  if (OKForBSwap && MatchBSwaps)
+    Intrin = Intrinsic::bswap;
+  else if (OKForBitReverse && MatchBitReversals)
+    Intrin = Intrinsic::bitreverse;
+  else
+    return false;
+
+  Function *F = Intrinsic::getDeclaration(I->getModule(), Intrin, ITy);
+  InsertedInsts.push_back(CallInst::Create(F, Res->Provider, "rev", I));
+  return true;
+}
diff --git a/contrib/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp b/contrib/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
index dc07440..2f3c311 100644
--- a/contrib/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
+++ b/contrib/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
@@ -970,15 +970,34 @@ static Value *valueHasFloatPrecision(Value *Val) {
   return nullptr;
 }
 
-//===----------------------------------------------------------------------===//
-// Double -> Float Shrinking Optimizations for Unary Functions like 'floor'
+/// Any floating-point library function that we're trying to simplify will have
+/// a signature of the form: fptype foo(fptype param1, fptype param2, ...).
+/// CheckDoubleTy indicates that 'fptype' must be 'double'.
+static bool matchesFPLibFunctionSignature(const Function *F, unsigned NumParams,
+                                          bool CheckDoubleTy) {
+  FunctionType *FT = F->getFunctionType();
+  if (FT->getNumParams() != NumParams)
+    return false;
+
+  // The return type must match what we're looking for.
+  Type *RetTy = FT->getReturnType();
+  if (CheckDoubleTy ? !RetTy->isDoubleTy() : !RetTy->isFloatingPointTy())
+    return false;
+
+  // Each parameter must match the return type, and therefore, match every other
+  // parameter too.
+  for (const Type *ParamTy : FT->params())
+    if (ParamTy != RetTy)
+      return false;
 
-Value *LibCallSimplifier::optimizeUnaryDoubleFP(CallInst *CI, IRBuilder<> &B,
-                                                bool CheckRetType) {
+  return true;
+}
+
+/// Shrink double -> float for unary functions like 'floor'.
+static Value *optimizeUnaryDoubleFP(CallInst *CI, IRBuilder<> &B,
+                                    bool CheckRetType) {
   Function *Callee = CI->getCalledFunction();
-  FunctionType *FT = Callee->getFunctionType();
-  if (FT->getNumParams() != 1 || !FT->getReturnType()->isDoubleTy() ||
-      !FT->getParamType(0)->isDoubleTy())
+  if (!matchesFPLibFunctionSignature(Callee, 1, true))
     return nullptr;
 
   if (CheckRetType) {
@@ -1013,15 +1032,10 @@ Value *LibCallSimplifier::optimizeUnaryDoubleFP(CallInst *CI, IRBuilder<> &B,
   return B.CreateFPExt(V, B.getDoubleTy());
 }
 
-// Double -> Float Shrinking Optimizations for Binary Functions like 'fmin/fmax'
-Value *LibCallSimplifier::optimizeBinaryDoubleFP(CallInst *CI, IRBuilder<> &B) {
+/// Shrink double -> float for binary functions like 'fmin/fmax'.
+static Value *optimizeBinaryDoubleFP(CallInst *CI, IRBuilder<> &B) {
   Function *Callee = CI->getCalledFunction();
-  FunctionType *FT = Callee->getFunctionType();
-  // Just make sure this has 2 arguments of the same FP type, which match the
-  // result type.
-  if (FT->getNumParams() != 2 || FT->getReturnType() != FT->getParamType(0) ||
-      FT->getParamType(0) != FT->getParamType(1) ||
-      !FT->getParamType(0)->isFloatingPointTy())
+  if (!matchesFPLibFunctionSignature(Callee, 2, true))
     return nullptr;
 
   // If this is something like 'fmin((double)floatval1, (double)floatval2)',
@@ -1394,12 +1408,21 @@ Value *LibCallSimplifier::optimizeLog(CallInst *CI, IRBuilder<> &B) {
 
 Value *LibCallSimplifier::optimizeSqrt(CallInst *CI, IRBuilder<> &B) {
   Function *Callee = CI->getCalledFunction();
-  
+
   Value *Ret = nullptr;
   if (TLI->has(LibFunc::sqrtf) && (Callee->getName() == "sqrt" ||
                                    Callee->getIntrinsicID() == Intrinsic::sqrt))
     Ret = optimizeUnaryDoubleFP(CI, B, true);
 
+  // FIXME: Refactor - this check is repeated all over this file and even in the
+  // preceding call to shrink double -> float.
+
+  // Make sure this has 1 argument of FP type, which matches the result type.
+  FunctionType *FT = Callee->getFunctionType();
+  if (FT->getNumParams() != 1 || FT->getReturnType() != FT->getParamType(0) ||
+      !FT->getParamType(0)->isFloatingPointTy())
+    return Ret;
+
   if (!CI->hasUnsafeAlgebra())
     return Ret;