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, 122 insertions, 128 deletions

diff --git a/contrib/llvm/lib/Transforms/Scalar/LoopInterchange.cpp b/contrib/llvm/lib/Transforms/Scalar/LoopInterchange.cpp
index 9241ec3..e9f84ed 100644
--- a/contrib/llvm/lib/Transforms/Scalar/LoopInterchange.cpp
+++ b/contrib/llvm/lib/Transforms/Scalar/LoopInterchange.cpp
@@ -44,6 +44,10 @@ using namespace llvm;
 
 #define DEBUG_TYPE "loop-interchange"
 
+static cl::opt<int> LoopInterchangeCostThreshold(
+    "loop-interchange-threshold", cl::init(0), cl::Hidden,
+    cl::desc("Interchange if you gain more than this number"));
+
 namespace {
 
 typedef SmallVector<Loop *, 8> LoopVector;
@@ -75,30 +79,23 @@ static bool populateDependencyMatrix(CharMatrix &DepMatrix, unsigned Level,
   typedef SmallVector<Value *, 16> ValueVector;
   ValueVector MemInstr;
 
-  if (Level > MaxLoopNestDepth) {
-    DEBUG(dbgs() << "Cannot handle loops of depth greater than "
-                 << MaxLoopNestDepth << "\n");
-    return false;
-  }
-
   // For each block.
   for (Loop::block_iterator BB = L->block_begin(), BE = L->block_end();
        BB != BE; ++BB) {
     // Scan the BB and collect legal loads and stores.
     for (BasicBlock::iterator I = (*BB)->begin(), E = (*BB)->end(); I != E;
          ++I) {
-      Instruction *Ins = dyn_cast<Instruction>(I);
-      if (!Ins)
-        return false;
-      LoadInst *Ld = dyn_cast<LoadInst>(I);
-      StoreInst *St = dyn_cast<StoreInst>(I);
-      if (!St && !Ld)
-        continue;
-      if (Ld && !Ld->isSimple())
-        return false;
-      if (St && !St->isSimple())
+      if (!isa<Instruction>(I))
         return false;
-      MemInstr.push_back(&*I);
+      if (LoadInst *Ld = dyn_cast<LoadInst>(I)) {
+        if (!Ld->isSimple())
+          return false;
+        MemInstr.push_back(&*I);
+      } else if (StoreInst *St = dyn_cast<StoreInst>(I)) {
+        if (!St->isSimple())
+          return false;
+        MemInstr.push_back(&*I);
+      }
     }
   }
 
@@ -110,66 +107,63 @@ static bool populateDependencyMatrix(CharMatrix &DepMatrix, unsigned Level,
   for (I = MemInstr.begin(), IE = MemInstr.end(); I != IE; ++I) {
     for (J = I, JE = MemInstr.end(); J != JE; ++J) {
       std::vector<char> Dep;
-      Instruction *Src = dyn_cast<Instruction>(*I);
-      Instruction *Des = dyn_cast<Instruction>(*J);
-      if (Src == Des)
+      Instruction *Src = cast<Instruction>(*I);
+      Instruction *Dst = cast<Instruction>(*J);
+      if (Src == Dst)
         continue;
-      if (isa<LoadInst>(Src) && isa<LoadInst>(Des))
+      // Ignore Input dependencies.
+      if (isa<LoadInst>(Src) && isa<LoadInst>(Dst))
         continue;
-      if (auto D = DI->depends(Src, Des, true)) {
-        DEBUG(dbgs() << "Found Dependency between Src=" << Src << " Des=" << Des
-                     << "\n");
-        if (D->isFlow()) {
-          // TODO: Handle Flow dependence.Check if it is sufficient to populate
-          // the Dependence Matrix with the direction reversed.
-          DEBUG(dbgs() << "Flow dependence not handled");
-          return false;
-        }
-        if (D->isAnti()) {
-          DEBUG(dbgs() << "Found Anti dependence \n");
-          unsigned Levels = D->getLevels();
-          char Direction;
-          for (unsigned II = 1; II <= Levels; ++II) {
-            const SCEV *Distance = D->getDistance(II);
-            const SCEVConstant *SCEVConst =
-                dyn_cast_or_null<SCEVConstant>(Distance);
-            if (SCEVConst) {
-              const ConstantInt *CI = SCEVConst->getValue();
-              if (CI->isNegative())
-                Direction = '<';
-              else if (CI->isZero())
-                Direction = '=';
-              else
-                Direction = '>';
-              Dep.push_back(Direction);
-            } else if (D->isScalar(II)) {
-              Direction = 'S';
-              Dep.push_back(Direction);
-            } else {
-              unsigned Dir = D->getDirection(II);
-              if (Dir == Dependence::DVEntry::LT ||
-                  Dir == Dependence::DVEntry::LE)
-                Direction = '<';
-              else if (Dir == Dependence::DVEntry::GT ||
-                       Dir == Dependence::DVEntry::GE)
-                Direction = '>';
-              else if (Dir == Dependence::DVEntry::EQ)
-                Direction = '=';
-              else
-                Direction = '*';
-              Dep.push_back(Direction);
-            }
-          }
-          while (Dep.size() != Level) {
-            Dep.push_back('I');
+      // Track Output, Flow, and Anti dependencies.
+      if (auto D = DI->depends(Src, Dst, true)) {
+        assert(D->isOrdered() && "Expected an output, flow or anti dep.");
+        DEBUG(StringRef DepType =
+                  D->isFlow() ? "flow" : D->isAnti() ? "anti" : "output";
+              dbgs() << "Found " << DepType
+                     << " dependency between Src and Dst\n"
+                     << " Src:" << *Src << "\n Dst:" << *Dst << '\n');
+        unsigned Levels = D->getLevels();
+        char Direction;
+        for (unsigned II = 1; II <= Levels; ++II) {
+          const SCEV *Distance = D->getDistance(II);
+          const SCEVConstant *SCEVConst =
+              dyn_cast_or_null<SCEVConstant>(Distance);
+          if (SCEVConst) {
+            const ConstantInt *CI = SCEVConst->getValue();
+            if (CI->isNegative())
+              Direction = '<';
+            else if (CI->isZero())
+              Direction = '=';
+            else
+              Direction = '>';
+            Dep.push_back(Direction);
+          } else if (D->isScalar(II)) {
+            Direction = 'S';
+            Dep.push_back(Direction);
+          } else {
+            unsigned Dir = D->getDirection(II);
+            if (Dir == Dependence::DVEntry::LT ||
+                Dir == Dependence::DVEntry::LE)
+              Direction = '<';
+            else if (Dir == Dependence::DVEntry::GT ||
+                     Dir == Dependence::DVEntry::GE)
+              Direction = '>';
+            else if (Dir == Dependence::DVEntry::EQ)
+              Direction = '=';
+            else
+              Direction = '*';
+            Dep.push_back(Direction);
           }
+        }
+        while (Dep.size() != Level) {
+          Dep.push_back('I');
+        }
 
-          DepMatrix.push_back(Dep);
-          if (DepMatrix.size() > MaxMemInstrCount) {
-            DEBUG(dbgs() << "Cannot handle more than " << MaxMemInstrCount
-                         << " dependencies inside loop\n");
-            return false;
-          }
+        DepMatrix.push_back(Dep);
+        if (DepMatrix.size() > MaxMemInstrCount) {
+          DEBUG(dbgs() << "Cannot handle more than " << MaxMemInstrCount
+                       << " dependencies inside loop\n");
+          return false;
         }
       }
     }
@@ -183,8 +177,8 @@ static bool populateDependencyMatrix(CharMatrix &DepMatrix, unsigned Level,
 
 // A loop is moved from index 'from' to an index 'to'. Update the Dependence
 // matrix by exchanging the two columns.
-static void interChangeDepedencies(CharMatrix &DepMatrix, unsigned FromIndx,
-                                   unsigned ToIndx) {
+static void interChangeDependencies(CharMatrix &DepMatrix, unsigned FromIndx,
+                                    unsigned ToIndx) {
   unsigned numRows = DepMatrix.size();
   for (unsigned i = 0; i < numRows; ++i) {
     char TmpVal = DepMatrix[i][ToIndx];
@@ -211,7 +205,7 @@ static bool isOuterMostDepPositive(CharMatrix &DepMatrix, unsigned Row,
 static bool containsNoDependence(CharMatrix &DepMatrix, unsigned Row,
                                  unsigned Column) {
   for (unsigned i = 0; i < Column; ++i) {
-    if (DepMatrix[Row][i] != '=' || DepMatrix[Row][i] != 'S' ||
+    if (DepMatrix[Row][i] != '=' && DepMatrix[Row][i] != 'S' &&
         DepMatrix[Row][i] != 'I')
       return false;
   }
@@ -255,9 +249,8 @@ static bool validDepInterchange(CharMatrix &DepMatrix, unsigned Row,
 
 // Checks if it is legal to interchange 2 loops.
 // [Theorem] A permutation of the loops in a perfect nest is legal if and only
-// if
-// the direction matrix, after the same permutation is applied to its columns,
-// has no ">" direction as the leftmost non-"=" direction in any row.
+// if the direction matrix, after the same permutation is applied to its
+// columns, has no ">" direction as the leftmost non-"=" direction in any row.
 static bool isLegalToInterChangeLoops(CharMatrix &DepMatrix,
                                       unsigned InnerLoopId,
                                       unsigned OuterLoopId) {
@@ -269,8 +262,7 @@ static bool isLegalToInterChangeLoops(CharMatrix &DepMatrix,
     char OuterDep = DepMatrix[Row][OuterLoopId];
     if (InnerDep == '*' || OuterDep == '*')
       return false;
-    else if (!validDepInterchange(DepMatrix, Row, OuterLoopId, InnerDep,
-                                  OuterDep))
+    if (!validDepInterchange(DepMatrix, Row, OuterLoopId, InnerDep, OuterDep))
       return false;
   }
   return true;
@@ -278,7 +270,9 @@ static bool isLegalToInterChangeLoops(CharMatrix &DepMatrix,
 
 static void populateWorklist(Loop &L, SmallVector<LoopVector, 8> &V) {
 
-  DEBUG(dbgs() << "Calling populateWorklist called\n");
+  DEBUG(dbgs() << "Calling populateWorklist on Func: "
+               << L.getHeader()->getParent()->getName() << " Loop: %"
+               << L.getHeader()->getName() << '\n');
   LoopVector LoopList;
   Loop *CurrentLoop = &L;
   const std::vector<Loop *> *Vec = &CurrentLoop->getSubLoops();
@@ -315,8 +309,7 @@ static PHINode *getInductionVariable(Loop *L, ScalarEvolution *SE) {
     if (!AddRec || !AddRec->isAffine())
       continue;
     const SCEV *Step = AddRec->getStepRecurrence(*SE);
-    const SCEVConstant *C = dyn_cast<SCEVConstant>(Step);
-    if (!C)
+    if (!isa<SCEVConstant>(Step))
       continue;
     // Found the induction variable.
     // FIXME: Handle loops with more than one induction variable. Note that,
@@ -474,7 +467,7 @@ struct LoopInterchange : public FunctionPass {
     for (Loop *L : LoopList) {
       const SCEV *ExitCountOuter = SE->getBackedgeTakenCount(L);
       if (ExitCountOuter == SE->getCouldNotCompute()) {
-        DEBUG(dbgs() << "Couldn't compute Backedge count\n");
+        DEBUG(dbgs() << "Couldn't compute backedge count\n");
         return false;
       }
       if (L->getNumBackEdges() != 1) {
@@ -482,7 +475,7 @@ struct LoopInterchange : public FunctionPass {
         return false;
       }
       if (!L->getExitingBlock()) {
-        DEBUG(dbgs() << "Loop Doesn't have unique exit block\n");
+        DEBUG(dbgs() << "Loop doesn't have unique exit block\n");
         return false;
       }
     }
@@ -498,27 +491,32 @@ struct LoopInterchange : public FunctionPass {
   bool processLoopList(LoopVector LoopList, Function &F) {
 
     bool Changed = false;
-    CharMatrix DependencyMatrix;
-    if (LoopList.size() < 2) {
+    unsigned LoopNestDepth = LoopList.size();
+    if (LoopNestDepth < 2) {
       DEBUG(dbgs() << "Loop doesn't contain minimum nesting level.\n");
       return false;
     }
+    if (LoopNestDepth > MaxLoopNestDepth) {
+      DEBUG(dbgs() << "Cannot handle loops of depth greater than "
+                   << MaxLoopNestDepth << "\n");
+      return false;
+    }
     if (!isComputableLoopNest(LoopList)) {
-      DEBUG(dbgs() << "Not vaild loop candidate for interchange\n");
+      DEBUG(dbgs() << "Not valid loop candidate for interchange\n");
       return false;
     }
-    Loop *OuterMostLoop = *(LoopList.begin());
 
-    DEBUG(dbgs() << "Processing LoopList of size = " << LoopList.size()
-                 << "\n");
+    DEBUG(dbgs() << "Processing LoopList of size = " << LoopNestDepth << "\n");
 
-    if (!populateDependencyMatrix(DependencyMatrix, LoopList.size(),
+    CharMatrix DependencyMatrix;
+    Loop *OuterMostLoop = *(LoopList.begin());
+    if (!populateDependencyMatrix(DependencyMatrix, LoopNestDepth,
                                   OuterMostLoop, DI)) {
-      DEBUG(dbgs() << "Populating Dependency matrix failed\n");
+      DEBUG(dbgs() << "Populating dependency matrix failed\n");
       return false;
     }
 #ifdef DUMP_DEP_MATRICIES
-    DEBUG(dbgs() << "Dependence before inter change \n");
+    DEBUG(dbgs() << "Dependence before interchange\n");
     printDepMatrix(DependencyMatrix);
 #endif
 
@@ -556,10 +554,10 @@ struct LoopInterchange : public FunctionPass {
       std::swap(LoopList[i - 1], LoopList[i]);
 
       // Update the DependencyMatrix
-      interChangeDepedencies(DependencyMatrix, i, i - 1);
+      interChangeDependencies(DependencyMatrix, i, i - 1);
       DT->recalculate(F);
 #ifdef DUMP_DEP_MATRICIES
-      DEBUG(dbgs() << "Dependence after inter change \n");
+      DEBUG(dbgs() << "Dependence after interchange\n");
       printDepMatrix(DependencyMatrix);
 #endif
       Changed |= Interchanged;
@@ -571,7 +569,7 @@ struct LoopInterchange : public FunctionPass {
                    unsigned OuterLoopId, BasicBlock *LoopNestExit,
                    std::vector<std::vector<char>> &DependencyMatrix) {
 
-    DEBUG(dbgs() << "Processing Innder Loop Id = " << InnerLoopId
+    DEBUG(dbgs() << "Processing Inner Loop Id = " << InnerLoopId
                  << " and OuterLoopId = " << OuterLoopId << "\n");
     Loop *InnerLoop = LoopList[InnerLoopId];
     Loop *OuterLoop = LoopList[OuterLoopId];
@@ -585,7 +583,7 @@ struct LoopInterchange : public FunctionPass {
     DEBUG(dbgs() << "Loops are legal to interchange\n");
     LoopInterchangeProfitability LIP(OuterLoop, InnerLoop, SE);
     if (!LIP.isProfitable(InnerLoopId, OuterLoopId, DependencyMatrix)) {
-      DEBUG(dbgs() << "Interchanging Loops not profitable\n");
+      DEBUG(dbgs() << "Interchanging loops not profitable\n");
       return false;
     }
 
@@ -599,8 +597,8 @@ struct LoopInterchange : public FunctionPass {
 
 } // end of namespace
 bool LoopInterchangeLegality::areAllUsesReductions(Instruction *Ins, Loop *L) {
-  return !std::any_of(Ins->user_begin(), Ins->user_end(), [=](User *U) -> bool {
-    PHINode *UserIns = dyn_cast<PHINode>(U);
+  return none_of(Ins->users(), [=](User *U) -> bool {
+    auto *UserIns = dyn_cast<PHINode>(U);
     RecurrenceDescriptor RD;
     return !UserIns || !RecurrenceDescriptor::isReductionPHI(UserIns, L, RD);
   });
@@ -626,8 +624,7 @@ bool LoopInterchangeLegality::containsUnsafeInstructionsInLatch(
     // Stores corresponding to reductions are safe while concluding if tightly
     // nested.
     if (StoreInst *L = dyn_cast<StoreInst>(I)) {
-      PHINode *PHI = dyn_cast<PHINode>(L->getOperand(0));
-      if (!PHI)
+      if (!isa<PHINode>(L->getOperand(0)))
         return true;
     } else if (I->mayHaveSideEffects() || I->mayReadFromMemory())
       return true;
@@ -640,30 +637,30 @@ bool LoopInterchangeLegality::tightlyNested(Loop *OuterLoop, Loop *InnerLoop) {
   BasicBlock *InnerLoopPreHeader = InnerLoop->getLoopPreheader();
   BasicBlock *OuterLoopLatch = OuterLoop->getLoopLatch();
 
-  DEBUG(dbgs() << "Checking if Loops are Tightly Nested\n");
+  DEBUG(dbgs() << "Checking if loops are tightly nested\n");
 
   // A perfectly nested loop will not have any branch in between the outer and
   // inner block i.e. outer header will branch to either inner preheader and
   // outerloop latch.
-  BranchInst *outerLoopHeaderBI =
+  BranchInst *OuterLoopHeaderBI =
       dyn_cast<BranchInst>(OuterLoopHeader->getTerminator());
-  if (!outerLoopHeaderBI)
+  if (!OuterLoopHeaderBI)
     return false;
-  unsigned num = outerLoopHeaderBI->getNumSuccessors();
-  for (unsigned i = 0; i < num; i++) {
-    if (outerLoopHeaderBI->getSuccessor(i) != InnerLoopPreHeader &&
-        outerLoopHeaderBI->getSuccessor(i) != OuterLoopLatch)
+
+  for (unsigned i = 0, e = OuterLoopHeaderBI->getNumSuccessors(); i < e; ++i) {
+    if (OuterLoopHeaderBI->getSuccessor(i) != InnerLoopPreHeader &&
+        OuterLoopHeaderBI->getSuccessor(i) != OuterLoopLatch)
       return false;
   }
 
-  DEBUG(dbgs() << "Checking instructions in Loop header and Loop latch \n");
+  DEBUG(dbgs() << "Checking instructions in Loop header and Loop latch\n");
   // We do not have any basic block in between now make sure the outer header
   // and outer loop latch doesn't contain any unsafe instructions.
   if (containsUnsafeInstructionsInHeader(OuterLoopHeader) ||
       containsUnsafeInstructionsInLatch(OuterLoopLatch))
     return false;
 
-  DEBUG(dbgs() << "Loops are perfectly nested \n");
+  DEBUG(dbgs() << "Loops are perfectly nested\n");
   // We have a perfect loop nest.
   return true;
 }
@@ -703,7 +700,7 @@ bool LoopInterchangeLegality::findInductionAndReductions(
     RecurrenceDescriptor RD;
     InductionDescriptor ID;
     PHINode *PHI = cast<PHINode>(I);
-    if (InductionDescriptor::isInductionPHI(PHI, SE, ID))
+    if (InductionDescriptor::isInductionPHI(PHI, L, SE, ID))
       Inductions.push_back(PHI);
     else if (RecurrenceDescriptor::isReductionPHI(PHI, L, RD))
       Reductions.push_back(PHI);
@@ -852,8 +849,8 @@ bool LoopInterchangeLegality::canInterchangeLoops(unsigned InnerLoopId,
 
   if (!isLegalToInterChangeLoops(DepMatrix, InnerLoopId, OuterLoopId)) {
     DEBUG(dbgs() << "Failed interchange InnerLoopId = " << InnerLoopId
-                 << "and OuterLoopId = " << OuterLoopId
-                 << "due to dependence\n");
+                 << " and OuterLoopId = " << OuterLoopId
+                 << " due to dependence\n");
     return false;
   }
 
@@ -946,9 +943,9 @@ int LoopInterchangeProfitability::getInstrOrderCost() {
   return GoodOrder - BadOrder;
 }
 
-static bool isProfitabileForVectorization(unsigned InnerLoopId,
-                                          unsigned OuterLoopId,
-                                          CharMatrix &DepMatrix) {
+static bool isProfitableForVectorization(unsigned InnerLoopId,
+                                         unsigned OuterLoopId,
+                                         CharMatrix &DepMatrix) {
   // TODO: Improve this heuristic to catch more cases.
   // If the inner loop is loop independent or doesn't carry any dependency it is
   // profitable to move this to outer position.
@@ -977,16 +974,15 @@ bool LoopInterchangeProfitability::isProfitable(unsigned InnerLoopId,
   // This is rough cost estimation algorithm. It counts the good and bad order
   // of induction variables in the instruction and allows reordering if number
   // of bad orders is more than good.
-  int Cost = 0;
-  Cost += getInstrOrderCost();
+  int Cost = getInstrOrderCost();
   DEBUG(dbgs() << "Cost = " << Cost << "\n");
-  if (Cost < 0)
+  if (Cost < -LoopInterchangeCostThreshold)
     return true;
 
   // It is not profitable as per current cache profitability model. But check if
   // we can move this loop outside to improve parallelism.
   bool ImprovesPar =
-      isProfitabileForVectorization(InnerLoopId, OuterLoopId, DepMatrix);
+      isProfitableForVectorization(InnerLoopId, OuterLoopId, DepMatrix);
   return ImprovesPar;
 }
 
@@ -1022,8 +1018,6 @@ void LoopInterchangeTransform::restructureLoops(Loop *InnerLoop,
 }
 
 bool LoopInterchangeTransform::transform() {
-
-  DEBUG(dbgs() << "transform\n");
   bool Transformed = false;
   Instruction *InnerIndexVar;
 
@@ -1046,16 +1040,16 @@ bool LoopInterchangeTransform::transform() {
     // incremented/decremented.
     // TODO: This splitting logic may not work always. Fix this.
     splitInnerLoopLatch(InnerIndexVar);
-    DEBUG(dbgs() << "splitInnerLoopLatch Done\n");
+    DEBUG(dbgs() << "splitInnerLoopLatch done\n");
 
     // Splits the inner loops phi nodes out into a separate basic block.
     splitInnerLoopHeader();
-    DEBUG(dbgs() << "splitInnerLoopHeader Done\n");
+    DEBUG(dbgs() << "splitInnerLoopHeader done\n");
   }
 
   Transformed |= adjustLoopLinks();
   if (!Transformed) {
-    DEBUG(dbgs() << "adjustLoopLinks Failed\n");
+    DEBUG(dbgs() << "adjustLoopLinks failed\n");
     return false;
   }
 
@@ -1099,7 +1093,7 @@ void LoopInterchangeTransform::splitInnerLoopHeader() {
   }
 
   DEBUG(dbgs() << "Output of splitInnerLoopHeader InnerLoopHeaderSucc & "
-                  "InnerLoopHeader \n");
+                  "InnerLoopHeader\n");
 }
 
 /// \brief Move all instructions except the terminator from FromBB right before