Consistent use of the noduplicate attribute.

[oota-llvm.git] / lib / Transforms / Scalar / MemCpyOptimizer.cpp

diff --git a/lib/Transforms/Scalar/MemCpyOptimizer.cpp b/lib/Transforms/Scalar/MemCpyOptimizer.cpp
index 1f335573a5c5b7e1905882e7898f02157258cb4b..143ba38ec98f521311b2b9c52c734a15ed116699 100644 (file)
--- a/lib/Transforms/Scalar/MemCpyOptimizer.cpp
+++ b/lib/Transforms/Scalar/MemCpyOptimizer.cpp
@@ -75,6 +75,13 @@ static bool IsPointerOffset(Value *Ptr1, Value *Ptr2, int64_t &Offset,
                             const DataLayout &TD) {
   Ptr1 = Ptr1->stripPointerCasts();
   Ptr2 = Ptr2->stripPointerCasts();
+
+  // Handle the trivial case first.
+  if (Ptr1 == Ptr2) {
+    Offset = 0;
+    return true;
+  }
+
   GEPOperator *GEP1 = dyn_cast<GEPOperator>(Ptr1);
   GEPOperator *GEP2 = dyn_cast<GEPOperator>(Ptr2);
 
@@ -657,23 +664,21 @@ bool MemCpyOpt::performCallSlotOptzn(Instruction *cpy,
   // guarantees that it holds only undefined values when passed in (so the final
   // memcpy can be dropped), that it is not read or written between the call and
   // the memcpy, and that writing beyond the end of it is undefined.
-  SmallVector<User*, 8> srcUseList(srcAlloca->use_begin(),
-                                   srcAlloca->use_end());
+  SmallVector<User*, 8> srcUseList(srcAlloca->user_begin(),
+                                   srcAlloca->user_end());
   while (!srcUseList.empty()) {
-    User *UI = srcUseList.pop_back_val();
+    User *U = srcUseList.pop_back_val();
 
-    if (isa<BitCastInst>(UI) || isa<AddrSpaceCastInst>(UI)) {
-      for (User::use_iterator I = UI->use_begin(), E = UI->use_end();
-           I != E; ++I)
-        srcUseList.push_back(*I);
-    } else if (GetElementPtrInst *G = dyn_cast<GetElementPtrInst>(UI)) {
+    if (isa<BitCastInst>(U) || isa<AddrSpaceCastInst>(U)) {
+      for (User *UU : U->users())
+        srcUseList.push_back(UU);
+    } else if (GetElementPtrInst *G = dyn_cast<GetElementPtrInst>(U)) {
       if (G->hasAllZeroIndices())
-        for (User::use_iterator I = UI->use_begin(), E = UI->use_end();
-             I != E; ++I)
-          srcUseList.push_back(*I);
+        for (User *UU : U->users())
+          srcUseList.push_back(UU);
       else
         return false;
-    } else if (UI != C && UI != cpy) {
+    } else if (U != C && U != cpy) {
       return false;
     }
   }