[Executorch] Add broadcasting support to optimized op_sub

kimishpatel · kimishpatel · commit 0bf7766a24c8 · 2025-02-13T14:00:17.000-08:00
Summary: This diff builds on top of previous one to add support for limited handling of broadcasting for sub Test Plan: tests added Reviewers: Subscribers: Tasks: Tags: ghstack-source-id: d3ab77a Pull Request resolved: #8256
diff --git a/kernels/optimized/cpu/op_sub.cpp b/kernels/optimized/cpu/op_sub.cpp
@@ -15,6 +15,8 @@
 #include <executorch/runtime/kernel/kernel_includes.h>
 #include <executorch/runtime/platform/assert.h>
 
+#include <executorch/kernels/optimized/cpu/op_add_sub_impl.h>
+
 namespace torch {
 namespace executor {
 namespace native {
@@ -138,110 +140,9 @@ Tensor& opt_sub_out(
     }
   }
 
-  auto selected_optimized_path = select_optimized_path(a, b, out);
-  if (selected_optimized_path == ElementwiseOptimizedPath::kTreatAs1d) {
-    // Resize for dynamic shape
-    auto error = resize_tensor(out, a.sizes());
-    ET_KERNEL_CHECK_MSG(
-        ctx,
-        error == Error::Ok,
-        InvalidArgument,
-        out,
-        "Failed to resize output tensor.");
-
-    ET_SWITCH_REAL_TYPES(a_type, ctx, "sub.out", CTYPE, [&]() {
-      CTYPE alpha_val;
-      ET_KERNEL_CHECK(
-          ctx, utils::extract_scalar(alpha, &alpha_val), InvalidArgument, );
-
-      using Vec = executorch::vec::Vectorized<CTYPE>;
-      executorch::vec::map2<CTYPE>(
-          [alpha_val](Vec x, Vec y) { return x - Vec(alpha_val) * y; },
-          out.mutable_data_ptr<CTYPE>(),
-          a.const_data_ptr<CTYPE>(),
-          b.const_data_ptr<CTYPE>(),
-          out.numel());
-    });
-  } else if (selected_optimized_path != ElementwiseOptimizedPath::kNone) {
-    const Tensor* lhs;
-    const Tensor* rhs;
-    if (selected_optimized_path ==
-        ElementwiseOptimizedPath::kBroadcast2dBy1dReverseArguments) {
-      lhs = &b;
-      rhs = &a;
-    } else {
-      // Catch failure to update logic when subing new broadcasting possibility.
-      ET_DCHECK(
-          selected_optimized_path ==
-          ElementwiseOptimizedPath::kBroadcast2dBy1d);
-      lhs = &a;
-      rhs = &b;
-    }
-    auto error = resize_tensor(out, lhs->sizes());
-    ET_KERNEL_CHECK_MSG(
-        ctx,
-        error == Error::Ok,
-        InvalidArgument,
-        out,
-        "Failed to resize output tensor.");
-    ET_SWITCH_REAL_TYPES(out_type, ctx, "sub.out", CTYPE, [&]() {
-      CTYPE alpha_val;
-      ET_KERNEL_CHECK(
-          ctx, utils::extract_scalar(alpha, &alpha_val), InvalidArgument, );
-
-      using Vec = executorch::vec::Vectorized<CTYPE>;
-      if (selected_optimized_path ==
-          ElementwiseOptimizedPath::kBroadcast2dBy1dReverseArguments) {
-        executorch::vec::broadcasting_map_2d_by_1d<CTYPE>(
-            [alpha_val](Vec x, Vec y) { return y - Vec(alpha_val) * x; },
-            out.mutable_data_ptr<CTYPE>(),
-            lhs->const_data_ptr<CTYPE>(),
-            rhs->const_data_ptr<CTYPE>(),
-            lhs->sizes()[lhs->dim() - 2],
-            lhs->sizes()[lhs->dim() - 1]);
-      } else {
-        executorch::vec::broadcasting_map_2d_by_1d<CTYPE>(
-            [alpha_val](Vec x, Vec y) { return x - Vec(alpha_val) * y; },
-            out.mutable_data_ptr<CTYPE>(),
-            lhs->const_data_ptr<CTYPE>(),
-            rhs->const_data_ptr<CTYPE>(),
-            lhs->sizes()[lhs->dim() - 2],
-            lhs->sizes()[lhs->dim() - 1]);
-      }
-    });
-  } else {
-    ScalarType common_type =
-        promoteTypes(a_type, b_type, /*half_to_float*/ true);
-    ET_KERNEL_CHECK(ctx, canCast(common_type, out_type), InvalidArgument, out);
-
-    ET_KERNEL_CHECK(
-        ctx,
-        resize_to_broadcast_target_size(a, b, out) == Error::Ok,
-        InvalidArgument,
-        out);
-
-    ET_SWITCH_REALH_TYPES(a_type, ctx, "sub.out", CTYPE_A, [&]() {
-      ET_SWITCH_REALH_TYPES(b_type, ctx, "sub.out", CTYPE_B, [&]() {
-        using CTYPE_IN = typename torch::executor::
-            promote_types<CTYPE_A, CTYPE_B, /*half_to_float*/ true>::type;
-        ET_DCHECK(CppTypeToScalarType<CTYPE_IN>::value == common_type);
-        ET_SWITCH_REALH_TYPES(out_type, ctx, "sub.out", CTYPE_OUT, [&]() {
-          CTYPE_IN alpha_val;
-          ET_KERNEL_CHECK(
-              ctx, utils::extract_scalar(alpha, &alpha_val), InvalidArgument, );
-
-          SubInner<
-              can_cast<CTYPE_IN, CTYPE_OUT>::value,
-              CTYPE_A,
-              CTYPE_B,
-              CTYPE_IN,
-              CTYPE_OUT>::run(a, b, alpha_val, out);
-        });
-      });
-    });
-  }
-
-  return out;
+  static constexpr const char op_name[] = "sub.out";
+  return torch::executor::kernels::impl::opt_add_sub_out_impl<true, op_name>(
+      ctx, a, b, alpha, out);
 }
 
 Tensor& opt_sub_scalar_out(
diff --git a/kernels/optimized/cpu/targets.bzl b/kernels/optimized/cpu/targets.bzl
@@ -95,6 +95,7 @@ _OPTIMIZED_ATEN_OPS = (
         name = "op_sub",
         deps = [
             ":binary_ops",
+            ":add_sub_impl",
             "//executorch/kernels/portable/cpu:scalar_utils",
             "//executorch/kernels/portable/cpu/util:broadcast_util",
         ],
diff --git a/kernels/test/op_sub_test.cpp b/kernels/test/op_sub_test.cpp
@@ -99,6 +99,109 @@ class OpSubOutTest : public OperatorTest {
     EXPECT_TENSOR_CLOSE(out, tf.make(sizes, /*data=*/{0.1, 1.2, 3.4, 7.8}));
   }
 
+  template <ScalarType DTYPE>
+  void test_broadcast_3D() {
+    TensorFactory<DTYPE> tf_a;
+
+    Tensor a =
+        tf_a.make({2, 2, 3}, /*data=*/{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12});
+    Tensor b = tf_a.make({2, 1, 3}, /*data=*/{2, 3, 4, 5, 6, 7});
+
+    // Destination for output of mul.
+    Tensor out =
+        tf_a.make({2, 2, 3}, /*data=*/{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12});
+    Tensor expected =
+        tf_a.make({2, 2, 3}, /*data=*/{-1, -1, -1, 2, 2, 2, 2, 2, 2, 5, 5, 5});
+
+    // Check that it matches the expected output.
+    EXPECT_TENSOR_CLOSE(op_sub_out(a, b, 1.0, out), expected);
+    // b - a * 1.5 output should be
+    expected = tf_a.make(
+        {2, 2, 3},
+        /*data=*/
+        {0.5,
+         0.0,
+         -0.5,
+         -4.0,
+         -4.5,
+         -5.0,
+         -5.5,
+         -6.0,
+         -6.5,
+         -10.0,
+         -10.5,
+         -11.0});
+    EXPECT_TENSOR_CLOSE(op_sub_out(b, a, 1.5, out), expected);
+  }
+
+  template <ScalarType DTYPE>
+  void test_broadcast_4D() {
+    TensorFactory<DTYPE> tf_a;
+
+    Tensor a = tf_a.make(
+        {2, 2, 3, 5},
+        /*data=*/{1,  2,  3,  4,  5,  6,  7,  8,  9,  10, 11, 12, 13, 14, 15,
+                  16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30,
+                  31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45,
+                  46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60});
+    Tensor b = tf_a.make(
+        {2, 1, 3, 5},
+        /*data=*/{1,  2,  3,  4,  5,  6,  7,  8,  9,  10, 11, 12, 13, 14, 15,
+                  16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30});
+
+    // Destination for output of mul.
+    Tensor out = tf_a.zeros({2, 2, 3, 5});
+    Tensor expected = tf_a.make(
+        {2, 2, 3, 5},
+        /*data=*/{0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
+                  15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
+                  15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
+                  30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30});
+
+    // Check that it matches the expected output.
+    EXPECT_TENSOR_CLOSE(op_sub_out(a, b, 1.0, out), expected);
+    expected = tf_a.make(
+        {2, 2, 3, 5},
+        /*data=*/{0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
+                  0,   0,   0,   -15, -15, -15, -15, -15, -15, -15, -15, -15,
+                  -15, -15, -15, -15, -15, -15, -15, -15, -15, -15, -15, -15,
+                  -15, -15, -15, -15, -15, -15, -15, -15, -15, -30, -30, -30,
+                  -30, -30, -30, -30, -30, -30, -30, -30, -30, -30, -30, -30});
+    EXPECT_TENSOR_CLOSE(op_sub_out(b, a, 1.0, out), expected);
+
+    b = tf_a.make(
+        {2, 2, 1, 5}, /*data=*/{1,  2,  3,  4,  5,  6,  7,  8,  9,  10,
+                                11, 12, 13, 14, 15, 16, 17, 18, 19, 20});
+    out = tf_a.zeros({2, 2, 3, 5});
+    expected = tf_a.make(
+        {2, 2, 3, 5},
+        /*data=*/{0,  0,  0,  0,  0,  5,  5,  5,  5,  5,  10, 10, 10, 10, 10,
+                  10, 10, 10, 10, 10, 15, 15, 15, 15, 15, 20, 20, 20, 20, 20,
+                  20, 20, 20, 20, 20, 25, 25, 25, 25, 25, 30, 30, 30, 30, 30,
+                  30, 30, 30, 30, 30, 35, 35, 35, 35, 35, 40, 40, 40, 40, 40});
+
+    // Check that it matches the expected output.
+    EXPECT_TENSOR_CLOSE(op_sub_out(a, b, 1.0, out), expected);
+    expected = tf_a.make(
+        {2, 2, 3, 5},
+        /*data=*/{-0.5000,  -1.0000,  -1.5000,  -2.0000,  -2.5000,
+                  -8.0000,  -8.5000,  -9.0000,  -9.5000,  -10.0000,
+                  -15.5000, -16.0000, -16.5000, -17.0000, -17.5000,
+
+                  -18.0000, -18.5000, -19.0000, -19.5000, -20.0000,
+                  -25.5000, -26.0000, -26.5000, -27.0000, -27.5000,
+                  -33.0000, -33.5000, -34.0000, -34.5000, -35.0000,
+
+                  -35.5000, -36.0000, -36.5000, -37.0000, -37.5000,
+                  -43.0000, -43.5000, -44.0000, -44.5000, -45.0000,
+                  -50.5000, -51.0000, -51.5000, -52.0000, -52.5000,
+
+                  -53.0000, -53.5000, -54.0000, -54.5000, -55.0000,
+                  -60.5000, -61.0000, -61.5000, -62.0000, -62.5000,
+                  -68.0000, -68.5000, -69.0000, -69.5000, -70.0000});
+    EXPECT_TENSOR_CLOSE(op_sub_out(b, a, 1.5, out), expected);
+  }
+
   void test_sub_enumerate_a_types() {
 #define ENUMERATE_TEST_ENTRY(ctype, dtype) \
   test_sub_enumerate_b_types<ScalarType::dtype>();
@@ -237,6 +340,19 @@ TEST_F(OpSubOutTest, BroadcastScalarRank0Supported) {
   EXPECT_TENSOR_EQ(out, ret);
 }
 
+TEST_F(OpSubOutTest, BroadcastNDTest) {
+  // Test 3D tensors
+  test_broadcast_3D<ScalarType::Float>();
+  test_broadcast_3D<ScalarType::Half>();
+  // Sub doesnt yet support BFloat16
+  // test_broadcast_3D<ScalarType::BFloat16>();
+
+  // Test 4D tensors
+  test_broadcast_4D<ScalarType::Float>();
+  test_broadcast_4D<ScalarType::Half>();
+  // test_broadcast_4D<ScalarType::BFloat16>();
+}
+
 //
 // Death Tests
 //
