[PM/AA] Remove the addEscapingUse update API that won't be easy to

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

diff --git a/include/llvm/Analysis/AliasAnalysis.h b/include/llvm/Analysis/AliasAnalysis.h
index 747fb345a56565570993e3d1bcc3a1a63583f3fe..88695fe30fb925ed9487836ebd1d5b835221496f 100644 (file)
--- a/include/llvm/Analysis/AliasAnalysis.h
+++ b/include/llvm/Analysis/AliasAnalysis.h
@@ -56,6 +56,34 @@ class MemTransferInst;
 class MemIntrinsic;
 class DominatorTree;
 
+/// The possible results of an alias query.
+///
+/// These results are always computed between two MemoryLocation objects as
+/// a query to some alias analysis.
+///
+/// Note that these are unscoped enumerations because we would like to support
+/// implicitly testing a result for the existence of any possible aliasing with
+/// a conversion to bool, but an "enum class" doesn't support this. The
+/// canonical names from the literature are suffixed and unique anyways, and so
+/// they serve as global constants in LLVM for these results.
+///
+/// See docs/AliasAnalysis.html for more information on the specific meanings
+/// of these values.
+enum AliasResult {
+  /// The two locations do not alias at all.
+  ///
+  /// This value is arranged to convert to false, while all other values
+  /// convert to true. This allows a boolean context to convert the result to
+  /// a binary flag indicating whether there is the possibility of aliasing.
+  NoAlias = 0,
+  /// The two locations may or may not alias. This is the least precise result.
+  MayAlias,
+  /// The two locations alias, but only due to a partial overlap.
+  PartialAlias,
+  /// The two locations precisely alias each other.
+  MustAlias,
+};
+
 class AliasAnalysis {
 protected:
   const DataLayout *DL;
@@ -95,22 +123,6 @@ public:
   /// Alias Queries...
   ///
 
-  /// Alias analysis result - Either we know for sure that it does not alias, we
-  /// know for sure it must alias, or we don't know anything: The two pointers
-  /// _might_ alias.  This enum is designed so you can do things like:
-  ///     if (AA.alias(P1, P2)) { ... }
-  /// to check to see if two pointers might alias.
-  ///
-  /// See docs/AliasAnalysis.html for more information on the specific meanings
-  /// of these values.
-  ///
-  enum AliasResult {
-    NoAlias = 0,        ///< No dependencies.
-    MayAlias,           ///< Anything goes.
-    PartialAlias,       ///< Pointers differ, but pointees overlap.
-    MustAlias           ///< Pointers are equal.
-  };
-
   /// alias - The main low level interface to the alias analysis implementation.
   /// Returns an AliasResult indicating whether the two pointers are aliased to
   /// each other.  This is the interface that must be implemented by specific
@@ -199,6 +211,8 @@ public:
     /// (if it has any) are non-volatile loads from objects pointed to by its
     /// pointer-typed arguments, with arbitrary offsets.
     ///
+    /// This property corresponds to the LLVM IR 'argmemonly' attribute combined
+    /// with 'readonly' attribute.
     /// This property corresponds to the IntrReadArgMem LLVM intrinsic flag.
     OnlyReadsArgumentPointees = ArgumentPointees | Ref,
 
@@ -206,6 +220,7 @@ public:
     /// function (if it has any) are non-volatile loads and stores from objects
     /// pointed to by its pointer-typed arguments, with arbitrary offsets.
     ///
+    /// This property corresponds to the LLVM IR 'argmemonly' attribute.
     /// This property corresponds to the IntrReadWriteArgMem LLVM intrinsic flag.
     OnlyAccessesArgumentPointees = ArgumentPointees | ModRef,
 
@@ -506,30 +521,10 @@ public:
   ///
   virtual void deleteValue(Value *V);
 
-  /// copyValue - This method should be used whenever a preexisting value in the
-  /// program is copied or cloned, introducing a new value.  Note that analysis
-  /// implementations should tolerate clients that use this method to introduce
-  /// the same value multiple times: if the analysis already knows about a
-  /// value, it should ignore the request.
-  ///
-  virtual void copyValue(Value *From, Value *To);
-
-  /// addEscapingUse - This method should be used whenever an escaping use is
-  /// added to a pointer value.  Analysis implementations may either return
-  /// conservative responses for that value in the future, or may recompute
-  /// some or all internal state to continue providing precise responses.
-  ///
-  /// Escaping uses are considered by anything _except_ the following:
-  ///  - GEPs or bitcasts of the pointer
-  ///  - Loads through the pointer
-  ///  - Stores through (but not of) the pointer
-  virtual void addEscapingUse(Use &U);
-
   /// replaceWithNewValue - This method is the obvious combination of the two
   /// above, and it provided as a helper to simplify client code.
   ///
   void replaceWithNewValue(Value *Old, Value *New) {
-    copyValue(Old, New);
     deleteValue(Old);
   }
 };