add source lookup to bufferization canonicalization

[frgossen]

Nice! I think this is going in the direction that fixes our deallocation issue.

mlir/lib/Dialect/Bufferization/IR/BufferizationOps.cpp

453–455

You are essentially addressing this comment. I think this might also be the best place to walk up the chain of aliases as the deallocs are found below.

471

Did you do this?

"conform to the LLVM Coding Standards. You can use the clang-format-diff.py or git-clang-format tools to automatically format your patch properly." (see https://llvm.org/docs/Contributing.html#how-to-submit-a-patch)

472

This will give you the preceding op, not the definition of the operand. You are probably looking for something like cloneOp.getInput().getDefiningoperation().

mlir/test/Dialect/Bufferization/canonicalize.mlir

260

You want to add a // CHECK-LABEL: @Atanh_platform_elem_type_output_type here.

271

Please add a // CHECK return {{.*}} here to make clear beween which ops you want to check the absence of clone and dealloc.
Othweise, this will consider the following lines until the next check (or file end in this case), which can be confusing when adding more tests cases.

[kushanam]

Applying review changes

[frgossen]

This diff looks a bit odd, like it is not relative to the original code. You might want to read these.

• https://llvm.org/docs/Phabricator.html#phabricator-reviews
• https://moz-conduit.readthedocs.io/en/latest/arcanist-user.html#series-of-commits

mlir/test/Dialect/Bufferization/canonicalize.mlir

273

Missing :

mlir/lib/Dialect/Bufferization/IR/BufferizationOps.cpp

     // source op is being checked. Some ops like ReshapeOp are aliases to 
     // allocation ops and could prevent removal of unnecessary allocs.
     if(!sourceDeallocOp) {
-      Operation *source_op = cloneOp->getPrevNode();
+      Operation *source_op = cloneOp.getInput().getDefiningOp();
       while (dyn_cast<ViewLikeOpInterface>(source_op)) {
         llvm::Optional<Operation *> tmpDeallocOp =
           memref::findDealloc(source_op->getResult(0));

           sourceDeallocOp = tmpOp;
           break;
         }
-        source_op = source_op->getPrevNode();
+        if (!source_op->getNumOperands())
+          break;
+        source_op = source_op->getOperand(0).getDefiningOp();
       }
     }
 

mlir/test/Dialect/Bufferization/canonicalize.mlir

   memref.dealloc %2 : memref<?xf32>
   return %4 : memref<*xf32>
 }
+// CHECK-LABEL: @Atanh_platform_elem_type_output_type
 // CHECK-NOT: bufferization.clone
-// CHECK-NOT: memref.dealloc
+// CHECK-NOT: memref.dealloc
+// CHECK return {{.*}}