Merge clang, llvm, lld, lldb, compiler-rt and libc++ 5.0.0 release.

MFC r309126 (by emaste):

  Correct lld llvm-tblgen dependency file name

MFC r309169:

  Get rid of separate Subversion mergeinfo properties for llvm-dwarfdump
  and llvm-lto.  The mergeinfo confuses Subversion enormously, and these
  directories will just use the mergeinfo for llvm itself.

MFC r312765:

  Pull in r276136 from upstream llvm trunk (by Wei Mi):

    Use ValueOffsetPair to enhance value reuse during SCEV expansion.

    In D12090, the ExprValueMap was added to reuse existing value during
    SCEV expansion. However, const folding and sext/zext distribution can
    make the reuse still difficult.

    A simplified case is: suppose we know S1 expands to V1 in
    ExprValueMap, and
      S1 = S2 + C_a
      S3 = S2 + C_b
    where C_a and C_b are different SCEVConstants. Then we'd like to
    expand S3 as V1 - C_a + C_b instead of expanding S2 literally. It is
    helpful when S2 is a complex SCEV expr and S2 has no entry in
    ExprValueMap, which is usually caused by the fact that S3 is
    generated from S1 after const folding.

    In order to do that, we represent ExprValueMap as a mapping from SCEV
    to ValueOffsetPair. We will save both S1->{V1, 0} and S2->{V1, C_a}
    into the ExprValueMap when we create SCEV for V1. When S3 is
    expanded, it will first expand S2 to V1 - C_a because of S2->{V1,
    C_a} in the map, then expand S3 to V1 - C_a + C_b.

    Differential Revision: https://reviews.llvm.org/D21313

  This should fix assertion failures when building OpenCV >= 3.1.

  PR:		215649

MFC r312831:

  Revert r312765 for now, since it causes assertions when building
  lang/spidermonkey24.

  Reported by:	antoine
  PR:		215649

MFC r316511 (by jhb):

  Add an implementation of __ffssi2() derived from __ffsdi2().

  Newer versions of GCC include an __ffssi2() symbol in libgcc and the
  compiler can emit calls to it in generated code.  This is true for at
  least GCC 6.2 when compiling world for mips and mips64.

  Reviewed by:	jmallett, dim
  Sponsored by:	DARPA / AFRL
  Differential Revision:	https://reviews.freebsd.org/D10086

MFC r318601 (by adrian):

  [libcompiler-rt] add bswapdi2/bswapsi2

  This is required for mips gcc 6.3 userland to build/run.

  Reviewed by:	emaste, dim
  Approved by:	emaste
  Differential Revision:	https://reviews.freebsd.org/D10838

MFC r318884 (by emaste):

  lldb: map TRAP_CAP to a trace trap

  In the absense of a more specific handler for TRAP_CAP (generated by
  ENOTCAPABLE or ECAPMODE while in capability mode) treat it as a trace
  trap.

  Example usage (testing the bug in PR219173):

  % proccontrol -m trapcap lldb usr.bin/hexdump/obj/hexdump -- -Cv -s 1 /bin/ls
  ...
  (lldb) run
  Process 12980 launching
  Process 12980 launched: '.../usr.bin/hexdump/obj/hexdump' (x86_64)
  Process 12980 stopped
  * thread #1, stop reason = trace
      frame #0: 0x0000004b80c65f1a libc.so.7`__sys_lseek + 10
  ...

  In the future we should have LLDB control the trapcap procctl itself
  (as it does with ASLR), as well as report a specific stop reason.
  This change eliminates an assertion failure from LLDB for now.

MFC r319796:

  Remove a few unneeded files from libllvm, libclang and liblldb.

MFC r319885 (by emaste):

  lld: ELF: Fix ICF crash on absolute symbol relocations.

  If two sections contained relocations to absolute symbols with the same
  value we would crash when trying to access their sections. Add a check that
  both symbols point to sections before accessing their sections, and treat
  absolute symbols as equal if their values are equal.

  Obtained from:	LLD commit r292578

MFC r319918:

  Revert r319796 for now, it can cause undefined references when linking
  in some circumstances.

  Reported by:	Shawn Webb <shawn.webb@hardenedbsd.org>

MFC r319957 (by emaste):

  lld: Add armelf emulation mode

  Obtained from:	LLD r305375

MFC r321369:

  Upgrade our copies of clang, llvm, lld, lldb, compiler-rt and libc++ to
  5.0.0 (trunk r308421).  Upstream has branched for the 5.0.0 release,
  which should be in about a month.  Please report bugs and regressions,
  so we can get them into the release.

  Please note that from 3.5.0 onwards, clang, llvm and lldb require C++11
  support to build; see UPDATING for more information.

MFC r321420:

  Add a few more object files to liblldb, which should solve errors when
  linking the lldb executable in some cases.  In particular, when the
  -ffunction-sections -fdata-sections options are turned off, or
  ineffective.

  Reported by:	Shawn Webb, Mark Millard

MFC r321433:

  Cleanup stale Options.inc files from the previous libllvm build for
  clang 4.0.0.  Otherwise, these can get included before the two newly
  generated ones (which are different) for clang 5.0.0.

  Reported by:	Mark Millard

MFC r321439 (by bdrewery):

  Move llvm Options.inc hack from r321433 for NO_CLEAN to lib/clang/libllvm.

  The files are only ever generated to .OBJDIR, not to WORLDTMP (as a
  sysroot) and are only ever included from a compilation.  So using
  a beforebuild target here removes the file before the compilation
  tries to include it.

MFC r321664:

  Pull in r308891 from upstream llvm trunk (by Benjamin Kramer):

    [CodeGenPrepare] Cut off FindAllMemoryUses if there are too many uses.

    This avoids excessive compile time. The case I'm looking at is
    Function.cpp from an old version of LLVM that still had the giant
    memcmp string matcher in it. Before r308322 this compiled in about 2
    minutes, after it, clang takes infinite* time to compile it. With
    this patch we're at 5 min, which is still bad but this is a
    pathological case.

    The cut off at 20 uses was chosen by looking at other cut-offs in LLVM
    for user scanning. It's probably too high, but does the job and is
    very unlikely to regress anything.

    Fixes PR33900.

    * I'm impatient and aborted after 15 minutes, on the bug report it was
      killed after 2h.

  Pull in r308986 from upstream llvm trunk (by Simon Pilgrim):

    [X86][CGP] Reduce memcmp() expansion to 2 load pairs (PR33914)

    D35067/rL308322 attempted to support up to 4 load pairs for memcmp
    inlining which resulted in regressions for some optimized libc memcmp
    implementations (PR33914).

    Until we can match these more optimal cases, this patch reduces the
    memcmp expansion to a maximum of 2 load pairs (which matches what we
    do for -Os).

    This patch should be considered for the 5.0.0 release branch as well

    Differential Revision: https://reviews.llvm.org/D35830

  These fix a hang (or extremely long compile time) when building older
  LLVM ports.

  Reported by:    antoine
  PR:             219139

MFC r321719:

  Pull in r309503 from upstream clang trunk (by Richard Smith):

    PR33902: Invalidate line number cache when adding more text to
    existing buffer.

    This led to crashes as the line number cache would report a bogus
    line number for a line of code, and we'd try to find a nonexistent
    column within the line when printing diagnostics.

  This fixes an assertion when building the graphics/champlain port.

  Reported by:	antoine, kwm
  PR:		219139

MFC r321723:

  Upgrade our copies of clang, llvm, lld and lldb to r309439 from the
  upstream release_50 branch.  This is just after upstream's 5.0.0-rc1.

MFC r322320:

  Upgrade our copies of clang, llvm and libc++ to r310316 from the
  upstream release_50 branch.

MFC r322326 (by emaste):

  lldb: Make i386-*-freebsd expression work on JIT path

  * Enable i386 ABI creation for freebsd
  * Added an extra argument in ABISysV_i386::PrepareTrivialCall for mmap
    syscall
  * Unlike linux, the last argument of mmap is actually 64-bit(off_t).
    This requires us to push an additional word for the higher order bits.
  * Prior to this change, ktrace dump will show mmap failures due to
    invalid argument coming from the 6th mmap argument.

  Submitted by:	Karnajit Wangkhem
  Differential Revision:	https://reviews.llvm.org/D34776

MFC r322360 (by emaste):

  lldb: Report inferior signals as signals, not exceptions, on FreeBSD

  This is the FreeBSD equivalent of LLVM r238549.

  This serves 2 purposes:

  * LLDB should handle inferior process signals SIGSEGV/SIGILL/SIGBUS/
    SIGFPE the way it is suppose to be handled. Prior to this fix these
    signals will neither create a coredump, nor exit from the debugger
    or work for signal handling scenario.
  * eInvalidCrashReason need not report "unknown crash reason" if we have
    a valid si_signo

  llvm.org/pr23699

  Patch by Karnajit Wangkhem

  Differential Revision:  https://reviews.llvm.org/D35223

  Submitted by:	Karnajit Wangkhem
  Obtained from:	LLVM r310591

MFC r322474 (by emaste):

  lld: Add `-z muldefs` option.

  Obtained from:	LLVM r310757

MFC r322740:

  Upgrade our copies of clang, llvm, lld and libc++ to r311219 from the
  upstream release_50 branch.

MFC r322855:

  Upgrade our copies of clang, llvm, lldb and compiler-rt to r311606 from
  the upstream release_50 branch.

  As of this version, lib/msun's trig test should also work correctly
  again (see bug 220989 for more information).

  PR:		220989

MFC r323112:

  Upgrade our copies of clang, llvm, lldb and compiler-rt to r312293 from
  the upstream release_50 branch.  This corresponds to 5.0.0 rc4.

  As of this version, the cad/stepcode port should now compile in a more
  reasonable time on i386 (see bug 221836 for more information).

  PR:		221836

MFC r323245:

  Upgrade our copies of clang, llvm, lld, lldb, compiler-rt and libc++ to
  5.0.0 release (upstream r312559).

  Release notes for llvm, clang and lld will be available here soon:
  <http://releases.llvm.org/5.0.0/docs/ReleaseNotes.html>
  <http://releases.llvm.org/5.0.0/tools/clang/docs/ReleaseNotes.html>
  <http://releases.llvm.org/5.0.0/tools/lld/docs/ReleaseNotes.html>

  Relnotes:	yes

(cherry picked from commit 12cd91cf4c6b96a24427c0de5374916f2808d263)

1 files changed, 204 insertions, 64 deletions

diff --git a/contrib/llvm/lib/Analysis/CGSCCPassManager.cpp b/contrib/llvm/lib/Analysis/CGSCCPassManager.cpp
index 054bdc4..74b5d79 100644
--- a/contrib/llvm/lib/Analysis/CGSCCPassManager.cpp
+++ b/contrib/llvm/lib/Analysis/CGSCCPassManager.cpp
@@ -117,6 +117,7 @@ bool CGSCCAnalysisManagerModuleProxy::Result::invalidate(
       PA.allAnalysesInSetPreserved<AllAnalysesOn<LazyCallGraph::SCC>>();
 
   // Ok, we have a graph, so we can propagate the invalidation down into it.
+  G->buildRefSCCs();
   for (auto &RC : G->postorder_ref_sccs())
     for (auto &C : RC) {
       Optional<PreservedAnalyses> InnerPA;
@@ -195,18 +196,117 @@ FunctionAnalysisManagerCGSCCProxy::run(LazyCallGraph::SCC &C,
 bool FunctionAnalysisManagerCGSCCProxy::Result::invalidate(
     LazyCallGraph::SCC &C, const PreservedAnalyses &PA,
     CGSCCAnalysisManager::Invalidator &Inv) {
-  for (LazyCallGraph::Node &N : C)
-    FAM->invalidate(N.getFunction(), PA);
+  // If literally everything is preserved, we're done.
+  if (PA.areAllPreserved())
+    return false; // This is still a valid proxy.
+
+  // If this proxy isn't marked as preserved, then even if the result remains
+  // valid, the key itself may no longer be valid, so we clear everything.
+  //
+  // Note that in order to preserve this proxy, a module pass must ensure that
+  // the FAM has been completely updated to handle the deletion of functions.
+  // Specifically, any FAM-cached results for those functions need to have been
+  // forcibly cleared. When preserved, this proxy will only invalidate results
+  // cached on functions *still in the module* at the end of the module pass.
+  auto PAC = PA.getChecker<FunctionAnalysisManagerCGSCCProxy>();
+  if (!PAC.preserved() && !PAC.preservedSet<AllAnalysesOn<LazyCallGraph::SCC>>()) {
+    for (LazyCallGraph::Node &N : C)
+      FAM->clear(N.getFunction());
 
-  // This proxy doesn't need to handle invalidation itself. Instead, the
-  // module-level CGSCC proxy handles it above by ensuring that if the
-  // module-level FAM proxy becomes invalid the entire SCC layer, which
-  // includes this proxy, is cleared.
+    return true;
+  }
+
+  // Directly check if the relevant set is preserved.
+  bool AreFunctionAnalysesPreserved =
+      PA.allAnalysesInSetPreserved<AllAnalysesOn<Function>>();
+
+  // Now walk all the functions to see if any inner analysis invalidation is
+  // necessary.
+  for (LazyCallGraph::Node &N : C) {
+    Function &F = N.getFunction();
+    Optional<PreservedAnalyses> FunctionPA;
+
+    // Check to see whether the preserved set needs to be pruned based on
+    // SCC-level analysis invalidation that triggers deferred invalidation
+    // registered with the outer analysis manager proxy for this function.
+    if (auto *OuterProxy =
+            FAM->getCachedResult<CGSCCAnalysisManagerFunctionProxy>(F))
+      for (const auto &OuterInvalidationPair :
+           OuterProxy->getOuterInvalidations()) {
+        AnalysisKey *OuterAnalysisID = OuterInvalidationPair.first;
+        const auto &InnerAnalysisIDs = OuterInvalidationPair.second;
+        if (Inv.invalidate(OuterAnalysisID, C, PA)) {
+          if (!FunctionPA)
+            FunctionPA = PA;
+          for (AnalysisKey *InnerAnalysisID : InnerAnalysisIDs)
+            FunctionPA->abandon(InnerAnalysisID);
+        }
+      }
+
+    // Check if we needed a custom PA set, and if so we'll need to run the
+    // inner invalidation.
+    if (FunctionPA) {
+      FAM->invalidate(F, *FunctionPA);
+      continue;
+    }
+
+    // Otherwise we only need to do invalidation if the original PA set didn't
+    // preserve all function analyses.
+    if (!AreFunctionAnalysesPreserved)
+      FAM->invalidate(F, PA);
+  }
+
+  // Return false to indicate that this result is still a valid proxy.
   return false;
 }
 
 } // End llvm namespace
 
+/// When a new SCC is created for the graph and there might be function
+/// analysis results cached for the functions now in that SCC two forms of
+/// updates are required.
+///
+/// First, a proxy from the SCC to the FunctionAnalysisManager needs to be
+/// created so that any subsequent invalidation events to the SCC are
+/// propagated to the function analysis results cached for functions within it.
+///
+/// Second, if any of the functions within the SCC have analysis results with
+/// outer analysis dependencies, then those dependencies would point to the
+/// *wrong* SCC's analysis result. We forcibly invalidate the necessary
+/// function analyses so that they don't retain stale handles.
+static void updateNewSCCFunctionAnalyses(LazyCallGraph::SCC &C,
+                                         LazyCallGraph &G,
+                                         CGSCCAnalysisManager &AM) {
+  // Get the relevant function analysis manager.
+  auto &FAM =
+      AM.getResult<FunctionAnalysisManagerCGSCCProxy>(C, G).getManager();
+
+  // Now walk the functions in this SCC and invalidate any function analysis
+  // results that might have outer dependencies on an SCC analysis.
+  for (LazyCallGraph::Node &N : C) {
+    Function &F = N.getFunction();
+
+    auto *OuterProxy =
+        FAM.getCachedResult<CGSCCAnalysisManagerFunctionProxy>(F);
+    if (!OuterProxy)
+      // No outer analyses were queried, nothing to do.
+      continue;
+
+    // Forcibly abandon all the inner analyses with dependencies, but
+    // invalidate nothing else.
+    auto PA = PreservedAnalyses::all();
+    for (const auto &OuterInvalidationPair :
+         OuterProxy->getOuterInvalidations()) {
+      const auto &InnerAnalysisIDs = OuterInvalidationPair.second;
+      for (AnalysisKey *InnerAnalysisID : InnerAnalysisIDs)
+        PA.abandon(InnerAnalysisID);
+    }
+
+    // Now invalidate anything we found.
+    FAM.invalidate(F, PA);
+  }
+}
+
 namespace {
 /// Helper function to update both the \c CGSCCAnalysisManager \p AM and the \c
 /// CGSCCPassManager's \c CGSCCUpdateResult \p UR based on a range of newly
@@ -235,7 +335,6 @@ incorporateNewSCCRange(const SCCRangeT &NewSCCRange, LazyCallGraph &G,
     dbgs() << "Enqueuing the existing SCC in the worklist:" << *C << "\n";
 
   SCC *OldC = C;
-  (void)OldC;
 
   // Update the current SCC. Note that if we have new SCCs, this must actually
   // change the SCC.
@@ -244,6 +343,26 @@ incorporateNewSCCRange(const SCCRangeT &NewSCCRange, LazyCallGraph &G,
   C = &*NewSCCRange.begin();
   assert(G.lookupSCC(N) == C && "Failed to update current SCC!");
 
+  // If we had a cached FAM proxy originally, we will want to create more of
+  // them for each SCC that was split off.
+  bool NeedFAMProxy =
+      AM.getCachedResult<FunctionAnalysisManagerCGSCCProxy>(*OldC) != nullptr;
+
+  // We need to propagate an invalidation call to all but the newly current SCC
+  // because the outer pass manager won't do that for us after splitting them.
+  // FIXME: We should accept a PreservedAnalysis from the CG updater so that if
+  // there are preserved ananalyses we can avoid invalidating them here for
+  // split-off SCCs.
+  // We know however that this will preserve any FAM proxy so go ahead and mark
+  // that.
+  PreservedAnalyses PA;
+  PA.preserve<FunctionAnalysisManagerCGSCCProxy>();
+  AM.invalidate(*OldC, PA);
+
+  // Ensure the now-current SCC's function analyses are updated.
+  if (NeedFAMProxy)
+    updateNewSCCFunctionAnalyses(*C, G, AM);
+
   for (SCC &NewC :
        reverse(make_range(std::next(NewSCCRange.begin()), NewSCCRange.end()))) {
     assert(C != &NewC && "No need to re-visit the current SCC!");
@@ -251,6 +370,14 @@ incorporateNewSCCRange(const SCCRangeT &NewSCCRange, LazyCallGraph &G,
     UR.CWorklist.insert(&NewC);
     if (DebugLogging)
       dbgs() << "Enqueuing a newly formed SCC:" << NewC << "\n";
+
+    // Ensure new SCCs' function analyses are updated.
+    if (NeedFAMProxy)
+      updateNewSCCFunctionAnalyses(NewC, G, AM);
+
+    // Also propagate a normal invalidation to the new SCC as only the current
+    // will get one from the pass manager infrastructure.
+    AM.invalidate(NewC, PA);
   }
   return C;
 }
@@ -273,9 +400,9 @@ LazyCallGraph::SCC &llvm::updateCGAndAnalysisManagerForFunctionPass(
   // demoted edges.
   SmallVector<Constant *, 16> Worklist;
   SmallPtrSet<Constant *, 16> Visited;
-  SmallPtrSet<Function *, 16> RetainedEdges;
-  SmallSetVector<Function *, 4> PromotedRefTargets;
-  SmallSetVector<Function *, 4> DemotedCallTargets;
+  SmallPtrSet<Node *, 16> RetainedEdges;
+  SmallSetVector<Node *, 4> PromotedRefTargets;
+  SmallSetVector<Node *, 4> DemotedCallTargets;
 
   // First walk the function and handle all called functions. We do this first
   // because if there is a single call edge, whether there are ref edges is
@@ -284,7 +411,8 @@ LazyCallGraph::SCC &llvm::updateCGAndAnalysisManagerForFunctionPass(
     if (auto CS = CallSite(&I))
       if (Function *Callee = CS.getCalledFunction())
         if (Visited.insert(Callee).second && !Callee->isDeclaration()) {
-          const Edge *E = N.lookup(*Callee);
+          Node &CalleeN = *G.lookup(*Callee);
+          Edge *E = N->lookup(CalleeN);
           // FIXME: We should really handle adding new calls. While it will
           // make downstream usage more complex, there is no fundamental
           // limitation and it will allow passes within the CGSCC to be a bit
@@ -293,9 +421,9 @@ LazyCallGraph::SCC &llvm::updateCGAndAnalysisManagerForFunctionPass(
           assert(E && "No function transformations should introduce *new* "
                       "call edges! Any new calls should be modeled as "
                       "promoted existing ref edges!");
-          RetainedEdges.insert(Callee);
+          RetainedEdges.insert(&CalleeN);
           if (!E->isCall())
-            PromotedRefTargets.insert(Callee);
+            PromotedRefTargets.insert(&CalleeN);
         }
 
   // Now walk all references.
@@ -305,25 +433,31 @@ LazyCallGraph::SCC &llvm::updateCGAndAnalysisManagerForFunctionPass(
         if (Visited.insert(C).second)
           Worklist.push_back(C);
 
-  LazyCallGraph::visitReferences(Worklist, Visited, [&](Function &Referee) {
-    const Edge *E = N.lookup(Referee);
+  auto VisitRef = [&](Function &Referee) {
+    Node &RefereeN = *G.lookup(Referee);
+    Edge *E = N->lookup(RefereeN);
     // FIXME: Similarly to new calls, we also currently preclude
     // introducing new references. See above for details.
     assert(E && "No function transformations should introduce *new* ref "
                 "edges! Any new ref edges would require IPO which "
                 "function passes aren't allowed to do!");
-    RetainedEdges.insert(&Referee);
+    RetainedEdges.insert(&RefereeN);
     if (E->isCall())
-      DemotedCallTargets.insert(&Referee);
-  });
+      DemotedCallTargets.insert(&RefereeN);
+  };
+  LazyCallGraph::visitReferences(Worklist, Visited, VisitRef);
+
+  // Include synthetic reference edges to known, defined lib functions.
+  for (auto *F : G.getLibFunctions())
+    VisitRef(*F);
 
   // First remove all of the edges that are no longer present in this function.
   // We have to build a list of dead targets first and then remove them as the
   // data structures will all be invalidated by removing them.
   SmallVector<PointerIntPair<Node *, 1, Edge::Kind>, 4> DeadTargets;
-  for (Edge &E : N)
-    if (!RetainedEdges.count(&E.getFunction()))
-      DeadTargets.push_back({E.getNode(), E.getKind()});
+  for (Edge &E : *N)
+    if (!RetainedEdges.count(&E.getNode()))
+      DeadTargets.push_back({&E.getNode(), E.getKind()});
   for (auto DeadTarget : DeadTargets) {
     Node &TargetN = *DeadTarget.getPointer();
     bool IsCall = DeadTarget.getInt() == Edge::Call;
@@ -346,14 +480,6 @@ LazyCallGraph::SCC &llvm::updateCGAndAnalysisManagerForFunctionPass(
         // For separate SCCs this is trivial.
         RC->switchTrivialInternalEdgeToRef(N, TargetN);
       } else {
-        // Otherwise we may end up re-structuring the call graph. First,
-        // invalidate any SCC analyses. We have to do this before we split
-        // functions into new SCCs and lose track of where their analyses are
-        // cached.
-        // FIXME: We should accept a more precise preserved set here. For
-        // example, it might be possible to preserve some function analyses
-        // even as the SCC structure is changed.
-        AM.invalidate(*C, PreservedAnalyses::none());
         // Now update the call graph.
         C = incorporateNewSCCRange(RC->switchInternalEdgeToRef(N, TargetN), G,
                                    N, C, AM, UR, DebugLogging);
@@ -397,9 +523,8 @@ LazyCallGraph::SCC &llvm::updateCGAndAnalysisManagerForFunctionPass(
   // Next demote all the call edges that are now ref edges. This helps make
   // the SCCs small which should minimize the work below as we don't want to
   // form cycles that this would break.
-  for (Function *RefTarget : DemotedCallTargets) {
-    Node &TargetN = *G.lookup(*RefTarget);
-    SCC &TargetC = *G.lookupSCC(TargetN);
+  for (Node *RefTarget : DemotedCallTargets) {
+    SCC &TargetC = *G.lookupSCC(*RefTarget);
     RefSCC &TargetRC = TargetC.getOuterRefSCC();
 
     // The easy case is when the target RefSCC is not this RefSCC. This is
@@ -407,10 +532,10 @@ LazyCallGraph::SCC &llvm::updateCGAndAnalysisManagerForFunctionPass(
     if (&TargetRC != RC) {
       assert(RC->isAncestorOf(TargetRC) &&
              "Cannot potentially form RefSCC cycles here!");
-      RC->switchOutgoingEdgeToRef(N, TargetN);
+      RC->switchOutgoingEdgeToRef(N, *RefTarget);
       if (DebugLogging)
         dbgs() << "Switch outgoing call edge to a ref edge from '" << N
-               << "' to '" << TargetN << "'\n";
+               << "' to '" << *RefTarget << "'\n";
       continue;
     }
 
@@ -418,26 +543,18 @@ LazyCallGraph::SCC &llvm::updateCGAndAnalysisManagerForFunctionPass(
     // some SCCs.
     if (C != &TargetC) {
       // For separate SCCs this is trivial.
-      RC->switchTrivialInternalEdgeToRef(N, TargetN);
+      RC->switchTrivialInternalEdgeToRef(N, *RefTarget);
       continue;
     }
 
-    // Otherwise we may end up re-structuring the call graph. First, invalidate
-    // any SCC analyses. We have to do this before we split functions into new
-    // SCCs and lose track of where their analyses are cached.
-    // FIXME: We should accept a more precise preserved set here. For example,
-    // it might be possible to preserve some function analyses even as the SCC
-    // structure is changed.
-    AM.invalidate(*C, PreservedAnalyses::none());
     // Now update the call graph.
-    C = incorporateNewSCCRange(RC->switchInternalEdgeToRef(N, TargetN), G,
-                               N, C, AM, UR, DebugLogging);
+    C = incorporateNewSCCRange(RC->switchInternalEdgeToRef(N, *RefTarget), G, N,
+                               C, AM, UR, DebugLogging);
   }
 
   // Now promote ref edges into call edges.
-  for (Function *CallTarget : PromotedRefTargets) {
-    Node &TargetN = *G.lookup(*CallTarget);
-    SCC &TargetC = *G.lookupSCC(TargetN);
+  for (Node *CallTarget : PromotedRefTargets) {
+    SCC &TargetC = *G.lookupSCC(*CallTarget);
     RefSCC &TargetRC = TargetC.getOuterRefSCC();
 
     // The easy case is when the target RefSCC is not this RefSCC. This is
@@ -445,38 +562,61 @@ LazyCallGraph::SCC &llvm::updateCGAndAnalysisManagerForFunctionPass(
     if (&TargetRC != RC) {
       assert(RC->isAncestorOf(TargetRC) &&
              "Cannot potentially form RefSCC cycles here!");
-      RC->switchOutgoingEdgeToCall(N, TargetN);
+      RC->switchOutgoingEdgeToCall(N, *CallTarget);
       if (DebugLogging)
         dbgs() << "Switch outgoing ref edge to a call edge from '" << N
-               << "' to '" << TargetN << "'\n";
+               << "' to '" << *CallTarget << "'\n";
       continue;
     }
     if (DebugLogging)
       dbgs() << "Switch an internal ref edge to a call edge from '" << N
-             << "' to '" << TargetN << "'\n";
+             << "' to '" << *CallTarget << "'\n";
 
     // Otherwise we are switching an internal ref edge to a call edge. This
     // may merge away some SCCs, and we add those to the UpdateResult. We also
     // need to make sure to update the worklist in the event SCCs have moved
-    // before the current one in the post-order sequence.
+    // before the current one in the post-order sequence
+    bool HasFunctionAnalysisProxy = false;
     auto InitialSCCIndex = RC->find(*C) - RC->begin();
-    auto InvalidatedSCCs = RC->switchInternalEdgeToCall(N, TargetN);
-    if (!InvalidatedSCCs.empty()) {
+    bool FormedCycle = RC->switchInternalEdgeToCall(
+        N, *CallTarget, [&](ArrayRef<SCC *> MergedSCCs) {
+          for (SCC *MergedC : MergedSCCs) {
+            assert(MergedC != &TargetC && "Cannot merge away the target SCC!");
+
+            HasFunctionAnalysisProxy |=
+                AM.getCachedResult<FunctionAnalysisManagerCGSCCProxy>(
+                    *MergedC) != nullptr;
+
+            // Mark that this SCC will no longer be valid.
+            UR.InvalidatedSCCs.insert(MergedC);
+
+            // FIXME: We should really do a 'clear' here to forcibly release
+            // memory, but we don't have a good way of doing that and
+            // preserving the function analyses.
+            auto PA = PreservedAnalyses::allInSet<AllAnalysesOn<Function>>();
+            PA.preserve<FunctionAnalysisManagerCGSCCProxy>();
+            AM.invalidate(*MergedC, PA);
+          }
+        });
+
+    // If we formed a cycle by creating this call, we need to update more data
+    // structures.
+    if (FormedCycle) {
       C = &TargetC;
       assert(G.lookupSCC(N) == C && "Failed to update current SCC!");
 
-      // Any analyses cached for this SCC are no longer precise as the shape
-      // has changed by introducing this cycle.
-      AM.invalidate(*C, PreservedAnalyses::none());
-
-      for (SCC *InvalidatedC : InvalidatedSCCs) {
-        assert(InvalidatedC != C && "Cannot invalidate the current SCC!");
-        UR.InvalidatedSCCs.insert(InvalidatedC);
+      // If one of the invalidated SCCs had a cached proxy to a function
+      // analysis manager, we need to create a proxy in the new current SCC as
+      // the invaliadted SCCs had their functions moved.
+      if (HasFunctionAnalysisProxy)
+        AM.getResult<FunctionAnalysisManagerCGSCCProxy>(*C, G);
 
-        // Also clear any cached analyses for the SCCs that are dead. This
-        // isn't really necessary for correctness but can release memory.
-        AM.clear(*InvalidatedC);
-      }
+      // Any analyses cached for this SCC are no longer precise as the shape
+      // has changed by introducing this cycle. However, we have taken care to
+      // update the proxies so it remains valide.
+      auto PA = PreservedAnalyses::allInSet<AllAnalysesOn<Function>>();
+      PA.preserve<FunctionAnalysisManagerCGSCCProxy>();
+      AM.invalidate(*C, PA);
     }
     auto NewSCCIndex = RC->find(*C) - RC->begin();
     if (InitialSCCIndex < NewSCCIndex) {