MemCpyOpt: address review

Author: artagnon

llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp

@@ -638,6 +638,7 @@ bool MemCpyOptPass::processStoreOfLoad(StoreInst *SI, LoadInst *LI,
   if (!LI->isSimple() || !LI->hasOneUse() || LI->getParent() != SI->getParent())
     return false;
 
+  BatchAAResults BAA(*AA);
   auto *T = LI->getType();
   // Don't introduce calls to memcpy/memmove intrinsics out of thin air if
   // the corresponding libcalls are not available.
@@ -653,12 +654,11 @@ bool MemCpyOptPass::processStoreOfLoad(StoreInst *SI, LoadInst *LI,
     // We use MSSA to check if an instruction may store to the memory we load
     // from in between the load and the store. If such an instruction is found,
     // we try to promote there instead of at the store position.
-    BatchAAResults BAA(*AA);
-    auto *Clobber =
-        cast<MemoryUseOrDef>(MSSA->getWalker()->getClobberingMemoryAccess(
-            StoreAccess->getDefiningAccess(), LoadLoc, BAA));
-    Instruction *P =
-        MSSA->dominates(LoadAccess, Clobber) ? Clobber->getMemoryInst() : SI;
+    auto *Clobber = MSSA->getWalker()->getClobberingMemoryAccess(
+        StoreAccess->getDefiningAccess(), LoadLoc, BAA);
+    Instruction *P = MSSA->dominates(LoadAccess, Clobber)
+                         ? cast<MemoryUseOrDef>(Clobber)->getMemoryInst()
+                         : SI;
 
     // If we found an instruction that may write to the loaded memory,
     // we can try to promote at this position instead of the store
@@ -706,7 +706,6 @@ bool MemCpyOptPass::processStoreOfLoad(StoreInst *SI, LoadInst *LI,
   // Detect cases where we're performing call slot forwarding, but
   // happen to be using a load-store pair to implement it, rather than
   // a memcpy.
-  BatchAAResults BAA(*AA);
   auto GetCall = [&]() -> CallInst * {
     // We defer this expensive clobber walk until the cheap checks
     // have been done on the source inside performCallSlotOptzn.