am 1c4ad5ef: Merge branch \'upstream\' into merge-2012_09_10

* commit '1c4ad5ef4fab105f0c8af7edd026e00502fb6279': (446 commits)
  Revert r163556. Missed updates to tablegen files.
  Update function names to conform to guidelines.  No functional change intended.
  test/CodeGen/X86/ms-inline-asm.ll: Relax for non-darwin x86 targets. '##InlineAsm' could not be seen in other hosts.
  [ms-inline asm] Properly emit the asm directives when the AsmPrinterVariant and InlineAsmVariant don't match.
  Update test case for Release builds.
  Remove redundant semicolons which are null statements.
  Disable stack coloring because it makes dragonegg fail bootstrapping.
  [ms-inline asm] Pass the correct AsmVariant to the PrintAsmOperand() function and update the printOperand() function accordingly.
  [ms-inline asm] Add support for .att_syntax directive.
  Enable stack coloring.
  Don't attempt to use flags from predicated instructions.
  [Object] Extract Elf_Ehdr. Patch by Hemant Kulkarni!
  Stack Coloring: Handle the case where END markers come before BEGIN markers properly.
  Enhance PR11334 fix to support extload from v2f32/v4f32
  Add "blocked" heuristic to the Hexagon MI scheduler.
  Fold multiply by 0 or 1 when in UnsafeFPMath mode in SelectionDAG::getNode().
  whitespace
  Add boolean simplification support from CMOV
  Fix an assertion failure when optimising a shufflevector incorrectly into concat_vectors, and a followup bug with SelectionDAG::getNode() creating nodes with invalid types.
  Minor cleanup. No functional change.
  ...

1 files changed, 28 insertions, 10 deletions

diff --git a/include/llvm/Analysis/BranchProbabilityInfo.h b/include/llvm/Analysis/BranchProbabilityInfo.h
index 006daa0..c0567da 100644
--- a/include/llvm/Analysis/BranchProbabilityInfo.h
+++ b/include/llvm/Analysis/BranchProbabilityInfo.h
@@ -28,11 +28,14 @@ class raw_ostream;
 ///
 /// This is a function analysis pass which provides information on the relative
 /// probabilities of each "edge" in the function's CFG where such an edge is
-/// defined by a pair of basic blocks. The probability for a given block and
-/// a successor block are always relative to the probabilities of the other
-/// successor blocks. Another way of looking at it is that the probabilities
-/// for a given block B and each of its successors should sum to exactly
-/// one (100%).
+/// defined by a pair (PredBlock and an index in the successors). The
+/// probability of an edge from one block is always relative to the
+/// probabilities of other edges from the block. The probabilites of all edges
+/// from a block sum to exactly one (100%).
+/// We use a pair (PredBlock and an index in the successors) to uniquely
+/// identify an edge, since we can have multiple edges from Src to Dst.
+/// As an example, we can have a switch which jumps to Dst with value 0 and
+/// value 10.
 class BranchProbabilityInfo : public FunctionPass {
 public:
   static char ID;
@@ -52,6 +55,12 @@ public:
   /// leaving the 'Src' block. The returned probability is never zero, and can
   /// only be one if the source block has only one successor.
   BranchProbability getEdgeProbability(const BasicBlock *Src,
+                                       unsigned IndexInSuccessors) const;
+
+  /// \brief Get the probability of going from Src to Dst.
+  ///
+  /// It returns the sum of all probabilities for edges from Src to Dst.
+  BranchProbability getEdgeProbability(const BasicBlock *Src,
                                        const BasicBlock *Dst) const;
 
   /// \brief Test if an edge is hot relative to other out-edges of the Src.
@@ -74,25 +83,34 @@ public:
   raw_ostream &printEdgeProbability(raw_ostream &OS, const BasicBlock *Src,
                                     const BasicBlock *Dst) const;
 
-  /// \brief Get the raw edge weight calculated for the block pair.
+  /// \brief Get the raw edge weight calculated for the edge.
   ///
   /// This returns the raw edge weight. It is guaranteed to fall between 1 and
   /// UINT32_MAX. Note that the raw edge weight is not meaningful in isolation.
   /// This interface should be very carefully, and primarily by routines that
   /// are updating the analysis by later calling setEdgeWeight.
+  uint32_t getEdgeWeight(const BasicBlock *Src,
+                         unsigned IndexInSuccessors) const;
+
+  /// \brief Get the raw edge weight calculated for the block pair.
+  ///
+  /// This returns the sum of all raw edge weights from Src to Dst.
+  /// It is guaranteed to fall between 1 and UINT32_MAX.
   uint32_t getEdgeWeight(const BasicBlock *Src, const BasicBlock *Dst) const;
 
-  /// \brief Set the raw edge weight for the block pair.
+  /// \brief Set the raw edge weight for a given edge.
   ///
-  /// This allows a pass to explicitly set the edge weight for a block. It can
+  /// This allows a pass to explicitly set the edge weight for an edge. It can
   /// be used when updating the CFG to update and preserve the branch
   /// probability information. Read the implementation of how these edge
   /// weights are calculated carefully before using!
-  void setEdgeWeight(const BasicBlock *Src, const BasicBlock *Dst,
+  void setEdgeWeight(const BasicBlock *Src, unsigned IndexInSuccessors,
                      uint32_t Weight);
 
 private:
-  typedef std::pair<const BasicBlock *, const BasicBlock *> Edge;
+  // Since we allow duplicate edges from one basic block to another, we use
+  // a pair (PredBlock and an index in the successors) to specify an edge.
+  typedef std::pair<const BasicBlock *, unsigned> Edge;
 
   // Default weight value. Used when we don't have information about the edge.
   // TODO: DEFAULT_WEIGHT makes sense during static predication, when none of