[mlir][normalize-memrefs] NFC Follow-up D125854

[tungld]

Summary

NFC follow-up D125854 to reflect some remaining comments in D125854

[bondhugula]

mlir/lib/Dialect/MemRef/Transforms/NormalizeMemRefs.cpp

172–173

This isn't what the comment had meant: please use a (single) dyn_cast instead of isa + cast - here and below. https://llvm.org/docs/ProgrammersManual.html#the-isa-cast-and-dyn-cast-templates

[tungld]

Reflect Uday's comments

[tungld]

@bondhugula thank you for your comments! I updated the patch accordingly.

mlir/lib/Dialect/MemRef/Transforms/NormalizeMemRefs.cpp

 bool NormalizeMemRefs::areMemRefsNormalizable(func::FuncOp funcOp) {
   // We assume external functions to be normalizable.
   if (funcOp.isExternal())
     return true;
 
   if (funcOp
           .walk([&](memref::AllocOp allocOp) -> WalkResult {
             Value oldMemRef = allocOp.getResult();
-            if (!oldMemRef.getType()
-                     .cast<MemRefType>()
-                     .getLayout()
-                     .isIdentity() &&
+            if (!allocOp.getType().getLayout().isIdentity() &&
                 !isMemRefNormalizable(oldMemRef.getUsers()))
               return WalkResult::interrupt();
             return WalkResult::advance();
           })
           .wasInterrupted())
     return false;
 
   if (funcOp
           .walk([&](func::CallOp callOp) -> WalkResult {
             for (unsigned resIndex :
                  llvm::seq<unsigned>(0, callOp.getNumResults())) {
               Value oldMemRef = callOp.getResult(resIndex);
-              if (oldMemRef.getType().isa<MemRefType>())
-                if (!oldMemRef.getType()
-                         .cast<MemRefType>()
-                         .getLayout()
-                         .isIdentity() &&
+              if (auto oldMemRefType =
+                      oldMemRef.getType().dyn_cast<MemRefType>())
+                if (!oldMemRefType.getLayout().isIdentity() &&
                     !isMemRefNormalizable(oldMemRef.getUsers()))
                   return WalkResult::interrupt();
             }
             return WalkResult::advance();
           })
           .wasInterrupted())
     return false;
 
   for (unsigned argIndex : llvm::seq<unsigned>(0, funcOp.getNumArguments())) {
     BlockArgument oldMemRef = funcOp.getArgument(argIndex);
-    if (oldMemRef.getType().isa<MemRefType>())
-      if (!oldMemRef.getType().cast<MemRefType>().getLayout().isIdentity() &&
+    if (auto oldMemRefType = oldMemRef.getType().dyn_cast<MemRefType>())
+      if (!oldMemRefType.getLayout().isIdentity() &&
           !isMemRefNormalizable(oldMemRef.getUsers()))
         return false;
   }
 
   return true;
 }
 
 /// Fetch the updated argument list and result of the function and update the