Metadata for annotating loops as parallel. The first consumer for this

metadata is the loop vectorizer.

See the documentation update for more info.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175060 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 14 insertions, 0 deletions

diff --git a/include/llvm/Analysis/LoopInfo.h b/include/llvm/Analysis/LoopInfo.h
index 9caa69a1d4..a20e065785 100644
--- a/include/llvm/Analysis/LoopInfo.h
+++ b/include/llvm/Analysis/LoopInfo.h
@@ -377,6 +377,20 @@ public:
   /// isSafeToClone - Return true if the loop body is safe to clone in practice.
   bool isSafeToClone() const;
 
+  /// Returns true if the loop is annotated parallel.
+  ///
+  /// A parallel loop can be assumed to not contain any dependencies between
+  /// iterations by the compiler. That is, any loop-carried dependency checking
+  /// can be skipped completely when parallelizing the loop on the target
+  /// machine. Thus, if the parallel loop information originates from the
+  /// programmer, e.g. via the OpenMP parallel for pragma, it is the
+  /// programmer's responsibility to ensure there are no loop-carried
+  /// dependencies. The final execution order of the instructions across
+  /// iterations is not guaranteed, thus, the end result might or might not
+  /// implement actual concurrent execution of instructions across multiple
+  /// iterations.
+  bool isAnnotatedParallel() const;
+
   /// hasDedicatedExits - Return true if no exit block for the loop
   /// has a predecessor that is outside the loop.
   bool hasDedicatedExits() const;