am 31675153: Merge branch \'upstream\' into merge_2

* commit '31675153bd2d7617db8cb6aeb58054934c7b9f73': (542 commits)
  MaximumSpanningTree::EdgeWeightCompare: Make this comparator actually be a strict weak ordering, and don't pass possibly-null pointers to dyn_cast.
  Fix misaligned access in MachO object file reader: despite containing an int64_t, Symbol64TableEntry is actually only stored with 4-byte alignment within the file.
  Fix unaligned memory accesses when performing relocations in X86 JIT. There's no cost to using memcpy here: the fixed code is optimized by LLVM to perfect machine code.
  Don't pass a null pointer to cast<> in its unit tests.
  Don't bind a reference to a dereferenced null pointer (for return value of WeakVH::operator*).
  [ms-inline asm] Do not report a Parser error when matching inline assembly.
  Ignore the documentation-suggested location for compile_commands.json
  The presence of the empty file "foo" unfortunately does not improve LLVM in any way.
  Remove unnecessary cast that was also unnecessarily casting away constness.
  Provide a portability macro for __builtin_trap.
  Fix macros arguments with an underscore, dot or dollar in them. This is based on a patch by Andy/PaX. I added the support for dot and dollar.
  [ms-inline asm] Expose the ErrorInfo from the MatchInstructionImpl.  In general, this is the index of the operand that failed to match.
  Formatting.  No functional change.
  Make the wording in of the "expected identifier" error in the .macro directive consistent with the other "expected identifier" errors. Extracted from the Andy/PaX patch. I added the test.
  Pacify PVS-Studio by changing the type rather than doing a cast, a tweak suggested by David Blaikie.
  Add support for the --param ssp-buffer-size= driver option. PR9673
  Use typedefs. Fix indentation. Extracted from the Andy/PaX patch.
  Remove unused variable. Extracted from the Andy/PaX patch.
  Fix typo. Extracted from the Andy/PaX patch.
  MCJIT: Tidy up the constructor.
  ...

1 files changed, 26 insertions, 11 deletions

diff --git a/lib/Transforms/Scalar/LICM.cpp b/lib/Transforms/Scalar/LICM.cpp
index 582948e..0192e92 100644
--- a/lib/Transforms/Scalar/LICM.cpp
+++ b/lib/Transforms/Scalar/LICM.cpp
@@ -175,7 +175,9 @@ namespace {
     bool canSinkOrHoistInst(Instruction &I);
     bool isNotUsedInLoop(Instruction &I);
 
-    void PromoteAliasSet(AliasSet &AS);
+    void PromoteAliasSet(AliasSet &AS,
+                         SmallVectorImpl<BasicBlock*> &ExitBlocks,
+                         SmallVectorImpl<Instruction*> &InsertPts);
   };
 }
 
@@ -256,10 +258,13 @@ bool LICM::runOnLoop(Loop *L, LPPassManager &LPM) {
   // Now that all loop invariants have been removed from the loop, promote any
   // memory references to scalars that we can.
   if (!DisablePromotion && Preheader && L->hasDedicatedExits()) {
+    SmallVector<BasicBlock *, 8> ExitBlocks;
+    SmallVector<Instruction *, 8> InsertPts;
+
     // Loop over all of the alias sets in the tracker object.
     for (AliasSetTracker::iterator I = CurAST->begin(), E = CurAST->end();
          I != E; ++I)
-      PromoteAliasSet(*I);
+      PromoteAliasSet(*I, ExitBlocks, InsertPts);
   }
 
   // Clear out loops state information for the next iteration
@@ -631,6 +636,7 @@ namespace {
     Value *SomePtr;  // Designated pointer to store to.
     SmallPtrSet<Value*, 4> &PointerMustAliases;
     SmallVectorImpl<BasicBlock*> &LoopExitBlocks;
+    SmallVectorImpl<Instruction*> &LoopInsertPts;
     AliasSetTracker &AST;
     DebugLoc DL;
     int Alignment;
@@ -638,11 +644,12 @@ namespace {
     LoopPromoter(Value *SP,
                  const SmallVectorImpl<Instruction*> &Insts, SSAUpdater &S,
                  SmallPtrSet<Value*, 4> &PMA,
-                 SmallVectorImpl<BasicBlock*> &LEB, AliasSetTracker &ast,
-                 DebugLoc dl, int alignment)
+                 SmallVectorImpl<BasicBlock*> &LEB,
+                 SmallVectorImpl<Instruction*> &LIP,
+                 AliasSetTracker &ast, DebugLoc dl, int alignment)
       : LoadAndStorePromoter(Insts, S), SomePtr(SP),
-        PointerMustAliases(PMA), LoopExitBlocks(LEB), AST(ast), DL(dl),
-        Alignment(alignment) {}
+        PointerMustAliases(PMA), LoopExitBlocks(LEB), LoopInsertPts(LIP),
+        AST(ast), DL(dl), Alignment(alignment) {}
 
     virtual bool isInstInList(Instruction *I,
                               const SmallVectorImpl<Instruction*> &) const {
@@ -662,7 +669,7 @@ namespace {
       for (unsigned i = 0, e = LoopExitBlocks.size(); i != e; ++i) {
         BasicBlock *ExitBlock = LoopExitBlocks[i];
         Value *LiveInValue = SSA.GetValueInMiddleOfBlock(ExitBlock);
-        Instruction *InsertPos = ExitBlock->getFirstInsertionPt();
+        Instruction *InsertPos = LoopInsertPts[i];
         StoreInst *NewSI = new StoreInst(LiveInValue, SomePtr, InsertPos);
         NewSI->setAlignment(Alignment);
         NewSI->setDebugLoc(DL);
@@ -684,7 +691,9 @@ namespace {
 /// looping over the stores in the loop, looking for stores to Must pointers
 /// which are loop invariant.
 ///
-void LICM::PromoteAliasSet(AliasSet &AS) {
+void LICM::PromoteAliasSet(AliasSet &AS,
+                           SmallVectorImpl<BasicBlock*> &ExitBlocks,
+                           SmallVectorImpl<Instruction*> &InsertPts) {
   // We can promote this alias set if it has a store, if it is a "Must" alias
   // set, if the pointer is loop invariant, and if we are not eliminating any
   // volatile loads or stores.
@@ -794,14 +803,20 @@ void LICM::PromoteAliasSet(AliasSet &AS) {
   // location is better than none.
   DebugLoc DL = LoopUses[0]->getDebugLoc();
 
-  SmallVector<BasicBlock*, 8> ExitBlocks;
-  CurLoop->getUniqueExitBlocks(ExitBlocks);
+  // Figure out the loop exits and their insertion points, if this is the
+  // first promotion.
+  if (ExitBlocks.empty()) {
+    CurLoop->getUniqueExitBlocks(ExitBlocks);
+    InsertPts.resize(ExitBlocks.size());
+    for (unsigned i = 0, e = ExitBlocks.size(); i != e; ++i)
+      InsertPts[i] = ExitBlocks[i]->getFirstInsertionPt();
+  }
 
   // We use the SSAUpdater interface to insert phi nodes as required.
   SmallVector<PHINode*, 16> NewPHIs;
   SSAUpdater SSA(&NewPHIs);
   LoopPromoter Promoter(SomePtr, LoopUses, SSA, PointerMustAliases, ExitBlocks,
-                        *CurAST, DL, Alignment);
+                        InsertPts, *CurAST, DL, Alignment);
 
   // Set up the preheader to have a definition of the value.  It is the live-out
   // value from the preheader that uses in the loop will use.