implement PR8576, deleting dead stores with intervening may-alias stores.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119927 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 9 insertions, 1 deletions

diff --git a/include/llvm/Analysis/MemoryDependenceAnalysis.h b/include/llvm/Analysis/MemoryDependenceAnalysis.h
index cc34992..c9c8116 100644
--- a/include/llvm/Analysis/MemoryDependenceAnalysis.h
+++ b/include/llvm/Analysis/MemoryDependenceAnalysis.h
@@ -335,11 +335,19 @@ namespace llvm {
     /// critical edges.
     void invalidateCachedPredecessors();
     
-  private:
+    /// getPointerDependencyFrom - Return the instruction on which a memory
+    /// location depends.  If isLoad is true, this routine ignores may-aliases
+    /// with read-only operations.  If isLoad is false, this routine ignores
+    /// may-aliases with reads from read-only locations.
+    ///
+    /// Note that this is an uncached query, and thus may be inefficient.
+    ///
     MemDepResult getPointerDependencyFrom(const AliasAnalysis::Location &Loc,
                                           bool isLoad, 
                                           BasicBlock::iterator ScanIt,
                                           BasicBlock *BB);
+    
+  private:
     MemDepResult getCallSiteDependencyFrom(CallSite C, bool isReadOnlyCall,
                                            BasicBlock::iterator ScanIt,
                                            BasicBlock *BB);