Update the branch weight metadata in JumpThreading pass.

[oota-llvm.git] / include / llvm / Analysis / CaptureTracking.h

diff --git a/include/llvm/Analysis/CaptureTracking.h b/include/llvm/Analysis/CaptureTracking.h
index b3390f47d2f3c2bd0b2d7c745c5091baad5e09e5..8d2c095d8585f57df92a33ab463d3e74711a27cf 100644 (file)
--- a/include/llvm/Analysis/CaptureTracking.h
+++ b/include/llvm/Analysis/CaptureTracking.h
@@ -15,7 +15,12 @@
 #define LLVM_ANALYSIS_CAPTURETRACKING_H
 
 namespace llvm {
+
   class Value;
+  class Use;
+  class Instruction;
+  class DominatorTree;
+  class OrderedBasicBlock;
 
   /// PointerMayBeCaptured - Return true if this pointer value may be captured
   /// by the enclosing function (which is required to exist).  This routine can
@@ -28,6 +33,49 @@ namespace llvm {
                             bool ReturnCaptures,
                             bool StoreCaptures);
 
+  /// PointerMayBeCapturedBefore - Return true if this pointer value may be
+  /// captured by the enclosing function (which is required to exist). If a
+  /// DominatorTree is provided, only captures which happen before the given
+  /// instruction are considered. This routine can be expensive, so consider
+  /// caching the results.  The boolean ReturnCaptures specifies whether
+  /// returning the value (or part of it) from the function counts as capturing
+  /// it or not.  The boolean StoreCaptures specified whether storing the value
+  /// (or part of it) into memory anywhere automatically counts as capturing it
+  /// or not. Captures by the provided instruction are considered if the
+  /// final parameter is true. An ordered basic block in \p OBB could be used
+  /// to speed up capture-tracker queries.
+  bool PointerMayBeCapturedBefore(const Value *V, bool ReturnCaptures,
+                                  bool StoreCaptures, const Instruction *I,
+                                  DominatorTree *DT, bool IncludeI = false,
+                                  OrderedBasicBlock *OBB = nullptr);
+
+  /// This callback is used in conjunction with PointerMayBeCaptured. In
+  /// addition to the interface here, you'll need to provide your own getters
+  /// to see whether anything was captured.
+  struct CaptureTracker {
+    virtual ~CaptureTracker();
+
+    /// tooManyUses - The depth of traversal has breached a limit. There may be
+    /// capturing instructions that will not be passed into captured().
+    virtual void tooManyUses() = 0;
+
+    /// shouldExplore - This is the use of a value derived from the pointer.
+    /// To prune the search (ie., assume that none of its users could possibly
+    /// capture) return false. To search it, return true.
+    ///
+    /// U->getUser() is always an Instruction.
+    virtual bool shouldExplore(const Use *U);
+
+    /// captured - Information about the pointer was captured by the user of
+    /// use U. Return true to stop the traversal or false to continue looking
+    /// for more capturing instructions.
+    virtual bool captured(const Use *U) = 0;
+  };
+
+  /// PointerMayBeCaptured - Visit the value and the values derived from it and
+  /// find values which appear to be capturing the pointer value. This feeds
+  /// results into and is controlled by the CaptureTracker object.
+  void PointerMayBeCaptured(const Value *V, CaptureTracker *Tracker);
 } // end namespace llvm
 
 #endif