Add support for llvm.vectorizer metadata

- llvm.loop.parallel metadata has been renamed to llvm.loop to be more generic
  by making the root of additional loop metadata.
  - Loop::isAnnotatedParallel now looks for llvm.loop and associated
    llvm.mem.parallel_loop_access
  - document llvm.loop and update llvm.mem.parallel_loop_access
- add support for llvm.vectorizer.width and llvm.vectorizer.unroll
  - document llvm.vectorizer.* metadata
  - add utility class LoopVectorizerHints for getting/setting loop metadata
  - use llvm.vectorizer.width=1 to indicate already vectorized instead of
    already_vectorized
- update existing tests that used llvm.loop.parallel and
  llvm.vectorizer.already_vectorized

Reviewed by: Nadav Rotem


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182802 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 17 insertions, 0 deletions

diff --git a/include/llvm/Analysis/LoopInfo.h b/include/llvm/Analysis/LoopInfo.h
index 783e347522..7b3eed7350 100644
--- a/include/llvm/Analysis/LoopInfo.h
+++ b/include/llvm/Analysis/LoopInfo.h
@@ -50,6 +50,7 @@ inline void RemoveFromVector(std::vector<T*> &V, T *N) {
 class DominatorTree;
 class LoopInfo;
 class Loop;
+class MDNode;
 class PHINode;
 class raw_ostream;
 template<class N, class M> class LoopInfoBase;
@@ -391,6 +392,22 @@ public:
   /// iterations.
   bool isAnnotatedParallel() const;
 
+  /// Return the llvm.loop loop id metadata node for this loop if it is present.
+  ///
+  /// If this loop contains the same llvm.loop metadata on each branch to the
+  /// header then the node is returned. If any latch instruction does not
+  /// contain llvm.loop or or if multiple latches contain different nodes then
+  /// 0 is returned.
+  MDNode *getLoopID() const;
+  /// Set the llvm.loop loop id metadata for this loop.
+  ///
+  /// The LoopID metadata node will be added to each terminator instruction in
+  /// the loop that branches to the loop header.
+  ///
+  /// The LoopID metadata node should have one or more operands and the first
+  /// operand should should be the node itself.
+  void setLoopID(MDNode *LoopID) const;
+
   /// hasDedicatedExits - Return true if no exit block for the loop
   /// has a predecessor that is outside the loop.
   bool hasDedicatedExits() const;