[ET][Portable][Build Size] Reduce build size of op_copy

Pull Request resolved: #6019

133 K -> 15 K
ghstack-source-id: 246944187
@exported-using-ghexport

Differential Revision: [D63994873](https://our.internmc.facebook.com/intern/diff/D63994873/)

Author: manuelcandales

kernels/portable/cpu/op_copy.cpp

@@ -9,6 +9,7 @@
 #include <cstring>
 
 #include <executorch/kernels/portable/cpu/util/broadcast_util.h>
+#include <executorch/kernels/portable/cpu/util/elementwise_util.h>
 #include <executorch/runtime/kernel/kernel_includes.h>
 
 namespace torch {
@@ -42,19 +43,18 @@ Tensor& copy_out(
   ET_KERNEL_CHECK(
       ctx, tensors_have_same_dim_order(in, out), InvalidArgument, out);
 
-  ScalarType in_type = in.scalar_type();
-  ScalarType src_type = src.scalar_type();
-
-  ET_SWITCH_REALHBBF16_TYPES(in_type, ctx, "copy.out", CTYPE, [&]() {
-    ET_SWITCH_REALHBBF16_TYPES(src_type, ctx, "copy.out", CTYPE_SRC, [&]() {
-      apply_binary_elementwise_fn<CTYPE, CTYPE_SRC, CTYPE>(
-          [](const CTYPE val_in, const CTYPE_SRC val_src) {
-            return convert<CTYPE, CTYPE_SRC>(val_src);
-          },
-          in,
-          src,
-          out);
-    });
+  static constexpr const char op_name[] = "copy.out";
+
+  ET_SWITCH_REALHBBF16_TYPES(in.scalar_type(), ctx, "copy.out", CTYPE, [&]() {
+    utils::apply_bitensor_elementwise_fn<CTYPE, op_name>(
+        [](const CTYPE _, const CTYPE val_src) { return val_src; },
+        ctx,
+        in,
+        utils::SupportedTensorDtypes::REALHBBF16,
+        src,
+        utils::SupportedTensorDtypes::REALHBBF16,
+        out,
+        utils::SupportedTensorDtypes::REALHBBF16);
   });
 
   return out;
@@ -75,19 +75,18 @@ Tensor& copy_(
   ET_KERNEL_CHECK(
       ctx, tensors_have_same_dim_order(in, src), InvalidArgument, in);
 
-  ScalarType in_type = in.scalar_type();
-  ScalarType src_type = src.scalar_type();
-
-  ET_SWITCH_REALHBBF16_TYPES(in_type, ctx, "copy_", CTYPE, [&]() {
-    ET_SWITCH_REALHBBF16_TYPES(src_type, ctx, "copy_", CTYPE_SRC, [&]() {
-      apply_binary_elementwise_fn<CTYPE, CTYPE_SRC, CTYPE>(
-          [](const CTYPE val_in, const CTYPE_SRC val_src) {
-            return convert<CTYPE, CTYPE_SRC>(val_src);
-          },
-          in,
-          src,
-          in);
-    });
+  static constexpr const char op_name[] = "copy_";
+
+  ET_SWITCH_REALHBBF16_TYPES(in.scalar_type(), ctx, "copy_", CTYPE, [&]() {
+    utils::apply_bitensor_elementwise_fn<CTYPE, op_name>(
+        [](const CTYPE _, const CTYPE val_src) { return val_src; },
+        ctx,
+        in,
+        utils::SupportedTensorDtypes::REALHBBF16,
+        src,
+        utils::SupportedTensorDtypes::REALHBBF16,
+        in,
+        utils::SupportedTensorDtypes::REALHBBF16);
   });
 
   return in;

shim/xplat/executorch/kernels/portable/op_registration_util.bzl

@@ -425,6 +425,8 @@ ATEN_OPS = (
         name = "op_copy",
         deps = [
             "//executorch/kernels/portable/cpu/util:broadcast_util",
+            "//executorch/kernels/portable/cpu/util:dtype_util",
+            "//executorch/kernels/portable/cpu/util:elementwise_util",
             "//executorch/runtime/core/exec_aten/util:scalar_type_util",
             "//executorch/runtime/core/exec_aten/util:tensor_util",
             ":scalar_utils",