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, 134 insertions, 64 deletions

diff --git a/contrib/llvm/lib/Transforms/Utils/LoopUnroll.cpp b/contrib/llvm/lib/Transforms/Utils/LoopUnroll.cpp
index 7f1f78f..e346ebd 100644
--- a/contrib/llvm/lib/Transforms/Utils/LoopUnroll.cpp
+++ b/contrib/llvm/lib/Transforms/Utils/LoopUnroll.cpp
@@ -23,11 +23,12 @@
 #include "llvm/Analysis/InstructionSimplify.h"
 #include "llvm/Analysis/LoopIterator.h"
 #include "llvm/Analysis/LoopPass.h"
+#include "llvm/Analysis/OptimizationDiagnosticInfo.h"
 #include "llvm/Analysis/ScalarEvolution.h"
 #include "llvm/IR/BasicBlock.h"
 #include "llvm/IR/DataLayout.h"
-#include "llvm/IR/DiagnosticInfo.h"
 #include "llvm/IR/Dominators.h"
+#include "llvm/IR/IntrinsicInst.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
@@ -46,7 +47,7 @@ STATISTIC(NumCompletelyUnrolled, "Number of loops completely unrolled");
 STATISTIC(NumUnrolled, "Number of loops unrolled (completely or otherwise)");
 
 static cl::opt<bool>
-UnrollRuntimeEpilog("unroll-runtime-epilog", cl::init(true), cl::Hidden,
+UnrollRuntimeEpilog("unroll-runtime-epilog", cl::init(false), cl::Hidden,
                     cl::desc("Allow runtime unrolled loops to be unrolled "
                              "with epilog instead of prolog."));
 
@@ -171,20 +172,58 @@ static bool needToInsertPhisForLCSSA(Loop *L, std::vector<BasicBlock *> Blocks,
   return false;
 }
 
+/// Adds ClonedBB to LoopInfo, creates a new loop for ClonedBB if necessary
+/// and adds a mapping from the original loop to the new loop to NewLoops.
+/// Returns nullptr if no new loop was created and a pointer to the
+/// original loop OriginalBB was part of otherwise.
+const Loop* llvm::addClonedBlockToLoopInfo(BasicBlock *OriginalBB,
+                                           BasicBlock *ClonedBB, LoopInfo *LI,
+                                           NewLoopsMap &NewLoops) {
+  // Figure out which loop New is in.
+  const Loop *OldLoop = LI->getLoopFor(OriginalBB);
+  assert(OldLoop && "Should (at least) be in the loop being unrolled!");
+
+  Loop *&NewLoop = NewLoops[OldLoop];
+  if (!NewLoop) {
+    // Found a new sub-loop.
+    assert(OriginalBB == OldLoop->getHeader() &&
+           "Header should be first in RPO");
+
+    NewLoop = new Loop();
+    Loop *NewLoopParent = NewLoops.lookup(OldLoop->getParentLoop());
+
+    if (NewLoopParent)
+      NewLoopParent->addChildLoop(NewLoop);
+    else
+      LI->addTopLevelLoop(NewLoop);
+
+    NewLoop->addBasicBlockToLoop(ClonedBB, *LI);
+    return OldLoop;
+  } else {
+    NewLoop->addBasicBlockToLoop(ClonedBB, *LI);
+    return nullptr;
+  }
+}
+
 /// Unroll the given loop by Count. The loop must be in LCSSA form. Returns true
 /// if unrolling was successful, or false if the loop was unmodified. Unrolling
 /// can only fail when the loop's latch block is not terminated by a conditional
 /// branch instruction. However, if the trip count (and multiple) are not known,
 /// loop unrolling will mostly produce more code that is no faster.
 ///
-/// TripCount is generally defined as the number of times the loop header
-/// executes. UnrollLoop relaxes the definition to permit early exits: here
-/// TripCount is the iteration on which control exits LatchBlock if no early
-/// exits were taken. Note that UnrollLoop assumes that the loop counter test
-/// terminates LatchBlock in order to remove unnecesssary instances of the
-/// test. In other words, control may exit the loop prior to TripCount
-/// iterations via an early branch, but control may not exit the loop from the
-/// LatchBlock's terminator prior to TripCount iterations.
+/// TripCount is the upper bound of the iteration on which control exits
+/// LatchBlock. Control may exit the loop prior to TripCount iterations either
+/// via an early branch in other loop block or via LatchBlock terminator. This
+/// is relaxed from the general definition of trip count which is the number of
+/// times the loop header executes. Note that UnrollLoop assumes that the loop
+/// counter test is in LatchBlock in order to remove unnecesssary instances of
+/// the test.  If control can exit the loop from the LatchBlock's terminator
+/// prior to TripCount iterations, flag PreserveCondBr needs to be set.
+///
+/// PreserveCondBr indicates whether the conditional branch of the LatchBlock
+/// needs to be preserved.  It is needed when we use trip count upper bound to
+/// fully unroll the loop. If PreserveOnlyFirst is also set then only the first
+/// conditional branch needs to be preserved.
 ///
 /// Similarly, TripMultiple divides the number of times that the LatchBlock may
 /// execute without exiting the loop.
@@ -196,15 +235,21 @@ static bool needToInsertPhisForLCSSA(Loop *L, std::vector<BasicBlock *> Blocks,
 /// runtime-unroll the loop if computing RuntimeTripCount will be expensive and
 /// AllowExpensiveTripCount is false.
 ///
+/// If we want to perform PGO-based loop peeling, PeelCount is set to the 
+/// number of iterations we want to peel off.
+///
 /// The LoopInfo Analysis that is passed will be kept consistent.
 ///
 /// This utility preserves LoopInfo. It will also preserve ScalarEvolution and
 /// DominatorTree if they are non-null.
 bool llvm::UnrollLoop(Loop *L, unsigned Count, unsigned TripCount, bool Force,
                       bool AllowRuntime, bool AllowExpensiveTripCount,
-                      unsigned TripMultiple, LoopInfo *LI, ScalarEvolution *SE,
-                      DominatorTree *DT, AssumptionCache *AC,
+                      bool PreserveCondBr, bool PreserveOnlyFirst,
+                      unsigned TripMultiple, unsigned PeelCount, LoopInfo *LI,
+                      ScalarEvolution *SE, DominatorTree *DT,
+                      AssumptionCache *AC, OptimizationRemarkEmitter *ORE,
                       bool PreserveLCSSA) {
+
   BasicBlock *Preheader = L->getLoopPreheader();
   if (!Preheader) {
     DEBUG(dbgs() << "  Can't unroll; loop preheader-insertion failed.\n");
@@ -250,9 +295,8 @@ bool llvm::UnrollLoop(Loop *L, unsigned Count, unsigned TripCount, bool Force,
   if (TripCount != 0 && Count > TripCount)
     Count = TripCount;
 
-  // Don't enter the unroll code if there is nothing to do. This way we don't
-  // need to support "partial unrolling by 1".
-  if (TripCount == 0 && Count < 2)
+  // Don't enter the unroll code if there is nothing to do.
+  if (TripCount == 0 && Count < 2 && PeelCount == 0)
     return false;
 
   assert(Count > 0);
@@ -272,14 +316,22 @@ bool llvm::UnrollLoop(Loop *L, unsigned Count, unsigned TripCount, bool Force,
   // now we just recompute LCSSA for the outer loop, but it should be possible
   // to fix it in-place.
   bool NeedToFixLCSSA = PreserveLCSSA && CompletelyUnroll &&
-      std::any_of(ExitBlocks.begin(), ExitBlocks.end(),
-                  [&](BasicBlock *BB) { return isa<PHINode>(BB->begin()); });
+                        any_of(ExitBlocks, [](const BasicBlock *BB) {
+                          return isa<PHINode>(BB->begin());
+                        });
 
   // We assume a run-time trip count if the compiler cannot
   // figure out the loop trip count and the unroll-runtime
   // flag is specified.
   bool RuntimeTripCount = (TripCount == 0 && Count > 0 && AllowRuntime);
 
+  assert((!RuntimeTripCount || !PeelCount) &&
+         "Did not expect runtime trip-count unrolling "
+         "and peeling for the same loop");
+
+  if (PeelCount)
+    peelLoop(L, PeelCount, LI, SE, DT, PreserveLCSSA);
+
   // Loops containing convergent instructions must have a count that divides
   // their TripMultiple.
   DEBUG(
@@ -293,9 +345,7 @@ bool llvm::UnrollLoop(Loop *L, unsigned Count, unsigned TripCount, bool Force,
                "Unroll count must divide trip multiple if loop contains a "
                "convergent operation.");
       });
-  // Don't output the runtime loop remainder if Count is a multiple of
-  // TripMultiple.  Such a remainder is never needed, and is unsafe if the loop
-  // contains a convergent instruction.
+
   if (RuntimeTripCount && TripMultiple % Count != 0 &&
       !UnrollRuntimeLoopRemainder(L, Count, AllowExpensiveTripCount,
                                   UnrollRuntimeEpilog, LI, SE, DT, 
@@ -322,35 +372,40 @@ bool llvm::UnrollLoop(Loop *L, unsigned Count, unsigned TripCount, bool Force,
       (unsigned)GreatestCommonDivisor64(Count, TripMultiple);
   }
 
+  using namespace ore;
   // Report the unrolling decision.
-  DebugLoc LoopLoc = L->getStartLoc();
-  Function *F = Header->getParent();
-  LLVMContext &Ctx = F->getContext();
-
   if (CompletelyUnroll) {
     DEBUG(dbgs() << "COMPLETELY UNROLLING loop %" << Header->getName()
           << " with trip count " << TripCount << "!\n");
-    emitOptimizationRemark(Ctx, DEBUG_TYPE, *F, LoopLoc,
-                           Twine("completely unrolled loop with ") +
-                               Twine(TripCount) + " iterations");
+    ORE->emit(OptimizationRemark(DEBUG_TYPE, "FullyUnrolled", L->getStartLoc(),
+                                 L->getHeader())
+              << "completely unrolled loop with "
+              << NV("UnrollCount", TripCount) << " iterations");
+  } else if (PeelCount) {
+    DEBUG(dbgs() << "PEELING loop %" << Header->getName()
+                 << " with iteration count " << PeelCount << "!\n");
+    ORE->emit(OptimizationRemark(DEBUG_TYPE, "Peeled", L->getStartLoc(),
+                                 L->getHeader())
+              << " peeled loop by " << NV("PeelCount", PeelCount)
+              << " iterations");
   } else {
-    auto EmitDiag = [&](const Twine &T) {
-      emitOptimizationRemark(Ctx, DEBUG_TYPE, *F, LoopLoc,
-                             "unrolled loop by a factor of " + Twine(Count) +
-                                 T);
-    };
+    OptimizationRemark Diag(DEBUG_TYPE, "PartialUnrolled", L->getStartLoc(),
+                            L->getHeader());
+    Diag << "unrolled loop by a factor of " << NV("UnrollCount", Count);
 
     DEBUG(dbgs() << "UNROLLING loop %" << Header->getName()
           << " by " << Count);
     if (TripMultiple == 0 || BreakoutTrip != TripMultiple) {
       DEBUG(dbgs() << " with a breakout at trip " << BreakoutTrip);
-      EmitDiag(" with a breakout at trip " + Twine(BreakoutTrip));
+      ORE->emit(Diag << " with a breakout at trip "
+                     << NV("BreakoutTrip", BreakoutTrip));
     } else if (TripMultiple != 1) {
       DEBUG(dbgs() << " with " << TripMultiple << " trips per branch");
-      EmitDiag(" with " + Twine(TripMultiple) + " trips per branch");
+      ORE->emit(Diag << " with " << NV("TripMultiple", TripMultiple)
+                     << " trips per branch");
     } else if (RuntimeTripCount) {
       DEBUG(dbgs() << " with run-time trip count");
-      EmitDiag(" with run-time trip count");
+      ORE->emit(Diag << " with run-time trip count");
     }
     DEBUG(dbgs() << "!\n");
   }
@@ -382,6 +437,15 @@ bool llvm::UnrollLoop(Loop *L, unsigned Count, unsigned TripCount, bool Force,
   LoopBlocksDFS::RPOIterator BlockEnd = DFS.endRPO();
 
   std::vector<BasicBlock*> UnrolledLoopBlocks = L->getBlocks();
+
+  // Loop Unrolling might create new loops. While we do preserve LoopInfo, we
+  // might break loop-simplified form for these loops (as they, e.g., would
+  // share the same exit blocks). We'll keep track of loops for which we can
+  // break this so that later we can re-simplify them.
+  SmallSetVector<Loop *, 4> LoopsToSimplify;
+  for (Loop *SubLoop : *L)
+    LoopsToSimplify.insert(SubLoop);
+
   for (unsigned It = 1; It != Count; ++It) {
     std::vector<BasicBlock*> NewBlocks;
     SmallDenseMap<const Loop *, Loop *, 4> NewLoops;
@@ -397,27 +461,14 @@ bool llvm::UnrollLoop(Loop *L, unsigned Count, unsigned TripCount, bool Force,
         assert(LI->getLoopFor(*BB) == L && "Header should not be in a sub-loop");
         L->addBasicBlockToLoop(New, *LI);
       } else {
-        // Figure out which loop New is in.
-        const Loop *OldLoop = LI->getLoopFor(*BB);
-        assert(OldLoop && "Should (at least) be in the loop being unrolled!");
-
-        Loop *&NewLoop = NewLoops[OldLoop];
-        if (!NewLoop) {
-          // Found a new sub-loop.
-          assert(*BB == OldLoop->getHeader() &&
-                 "Header should be first in RPO");
-
-          Loop *NewLoopParent = NewLoops.lookup(OldLoop->getParentLoop());
-          assert(NewLoopParent &&
-                 "Expected parent loop before sub-loop in RPO");
-          NewLoop = new Loop;
-          NewLoopParent->addChildLoop(NewLoop);
+        const Loop *OldLoop = addClonedBlockToLoopInfo(*BB, New, LI, NewLoops);
+        if (OldLoop) {
+          LoopsToSimplify.insert(NewLoops[OldLoop]);
 
           // Forget the old loop, since its inputs may have changed.
           if (SE)
             SE->forgetLoop(OldLoop);
         }
-        NewLoop->addBasicBlockToLoop(New, *LI);
       }
 
       if (*BB == Header)
@@ -480,9 +531,14 @@ bool llvm::UnrollLoop(Loop *L, unsigned Count, unsigned TripCount, bool Force,
     }
 
     // Remap all instructions in the most recent iteration
-    for (BasicBlock *NewBlock : NewBlocks)
-      for (Instruction &I : *NewBlock)
+    for (BasicBlock *NewBlock : NewBlocks) {
+      for (Instruction &I : *NewBlock) {
         ::remapInstruction(&I, LastValueMap);
+        if (auto *II = dyn_cast<IntrinsicInst>(&I))
+          if (II->getIntrinsicID() == Intrinsic::assume)
+            AC->registerAssumption(II);
+      }
+    }
   }
 
   // Loop over the PHI nodes in the original block, setting incoming values.
@@ -524,12 +580,16 @@ bool llvm::UnrollLoop(Loop *L, unsigned Count, unsigned TripCount, bool Force,
     if (CompletelyUnroll) {
       if (j == 0)
         Dest = LoopExit;
-      NeedConditional = false;
-    }
-
-    // If we know the trip count or a multiple of it, we can safely use an
-    // unconditional branch for some iterations.
-    if (j != BreakoutTrip && (TripMultiple == 0 || j % TripMultiple != 0)) {
+      // If using trip count upper bound to completely unroll, we need to keep
+      // the conditional branch except the last one because the loop may exit
+      // after any iteration.
+      assert(NeedConditional &&
+             "NeedCondition cannot be modified by both complete "
+             "unrolling and runtime unrolling");
+      NeedConditional = (PreserveCondBr && j && !(PreserveOnlyFirst && i != 0));
+    } else if (j != BreakoutTrip && (TripMultiple == 0 || j % TripMultiple != 0)) {
+      // If we know the trip count or a multiple of it, we can safely use an
+      // unconditional branch for some iterations.
       NeedConditional = false;
     }
 
@@ -595,10 +655,6 @@ bool llvm::UnrollLoop(Loop *L, unsigned Count, unsigned TripCount, bool Force,
     }
   }
 
-  // FIXME: We could register any cloned assumptions instead of clearing the
-  // whole function's cache.
-  AC->clear();
-
   // FIXME: We only preserve DT info for complete unrolling now. Incrementally
   // updating domtree after partial loop unrolling should also be easy.
   if (DT && !CompletelyUnroll)
@@ -607,7 +663,7 @@ bool llvm::UnrollLoop(Loop *L, unsigned Count, unsigned TripCount, bool Force,
     DEBUG(DT->verifyDomTree());
 
   // Simplify any new induction variables in the partially unrolled loop.
-  if (SE && !CompletelyUnroll) {
+  if (SE && !CompletelyUnroll && Count > 1) {
     SmallVector<WeakVH, 16> DeadInsts;
     simplifyLoopIVs(L, SE, DT, LI, DeadInsts);
 
@@ -636,6 +692,11 @@ bool llvm::UnrollLoop(Loop *L, unsigned Count, unsigned TripCount, bool Force,
     }
   }
 
+  // TODO: after peeling or unrolling, previously loop variant conditions are
+  // likely to fold to constants, eagerly propagating those here will require
+  // fewer cleanup passes to be run.  Alternatively, a LoopEarlyCSE might be
+  // appropriate.
+
   NumCompletelyUnrolled += CompletelyUnroll;
   ++NumUnrolled;
 
@@ -663,6 +724,11 @@ bool llvm::UnrollLoop(Loop *L, unsigned Count, unsigned TripCount, bool Force,
     if (!OuterL && !CompletelyUnroll)
       OuterL = L;
     if (OuterL) {
+      // OuterL includes all loops for which we can break loop-simplify, so
+      // it's sufficient to simplify only it (it'll recursively simplify inner
+      // loops too).
+      // TODO: That potentially might be compile-time expensive. We should try
+      // to fix the loop-simplified form incrementally.
       simplifyLoop(OuterL, DT, LI, SE, AC, PreserveLCSSA);
 
       // LCSSA must be performed on the outermost affected loop. The unrolled
@@ -678,6 +744,10 @@ bool llvm::UnrollLoop(Loop *L, unsigned Count, unsigned TripCount, bool Force,
       else
         assert(OuterL->isLCSSAForm(*DT) &&
                "Loops should be in LCSSA form after loop-unroll.");
+    } else {
+      // Simplify loops for which we might've broken loop-simplify form.
+      for (Loop *SubLoop : LoopsToSimplify)
+        simplifyLoop(SubLoop, DT, LI, SE, AC, PreserveLCSSA);
     }
   }