Support Half/BFloat16 in var (#7913)

Partial fix for #7748.

Author: swolchok

kernels/portable/cpu/op_var.cpp

@@ -38,7 +38,7 @@ void compute_variance(
           in,
           dim_list,
           out_ix);
-      CTYPE_OUT mean = sum / num;
+      CTYPE_OUT mean = sum / static_cast<CTYPE_OUT>(num);
       CTYPE_OUT sum2 = map_reduce_over_dim_list<CTYPE_IN, CTYPE_OUT>(
           [mean](CTYPE_IN v) {
             return (
@@ -90,8 +90,8 @@ Tensor& var_out(
 
   constexpr auto name = "var.out";
 
-  ET_SWITCH_FLOAT_TYPES(in.scalar_type(), ctx, name, CTYPE_IN, [&] {
-    ET_SWITCH_FLOAT_TYPES(out.scalar_type(), ctx, name, CTYPE_OUT, [&] {
+  ET_SWITCH_FLOATHBF16_TYPES(in.scalar_type(), ctx, name, CTYPE_IN, [&] {
+    ET_SWITCH_FLOATHBF16_TYPES(out.scalar_type(), ctx, name, CTYPE_OUT, [&] {
       compute_variance<CTYPE_IN, CTYPE_OUT>(in, out, dim_list, num, denom);
     });
   });
@@ -135,8 +135,8 @@ Tensor& var_correction_out(
   const size_t num = get_reduced_dim_product(in, dim_list);
   const double denom = num - correction_val;
 
-  ET_SWITCH_FLOAT_TYPES(in.scalar_type(), ctx, name, CTYPE_IN, [&] {
-    ET_SWITCH_FLOAT_TYPES(out.scalar_type(), ctx, name, CTYPE_OUT, [&] {
+  ET_SWITCH_FLOATHBF16_TYPES(in.scalar_type(), ctx, name, CTYPE_IN, [&] {
+    ET_SWITCH_FLOATHBF16_TYPES(out.scalar_type(), ctx, name, CTYPE_OUT, [&] {
       compute_variance<CTYPE_IN, CTYPE_OUT>(in, out, dim_list, num, denom);
     });
   });

kernels/test/op_var_test.cpp

@@ -25,6 +25,19 @@ using exec_aten::ScalarType;
 using exec_aten::Tensor;
 using torch::executor::testing::TensorFactory;
 
+namespace {
+void expect_tensor_close_with_increased_tol(
+    const Tensor& actual,
+    const Tensor& expected) {
+  if (actual.scalar_type() == ScalarType::BFloat16 ||
+      actual.scalar_type() == ScalarType::Half) {
+    EXPECT_TENSOR_CLOSE_WITH_TOL(expected, actual, 1e-2, 1e-2);
+  } else {
+    EXPECT_TENSOR_CLOSE(expected, actual);
+  }
+}
+} // namespace
+
 class OpVarOutTest : public OperatorTest {
  protected:
   Tensor& op_var_out(
@@ -142,7 +155,7 @@ class OpVarOutTest : public OperatorTest {
     op_var_out(
         self, optional_dim_list, /*unbiased=*/true, /*keepdim=*/true, out);
     // clang-format off
-    EXPECT_TENSOR_CLOSE(out, tf_out.make(
+    expect_tensor_close_with_increased_tol(out, tf_out.make(
       {2, 3, 1},
       {
         1.666667,
@@ -160,7 +173,7 @@ class OpVarOutTest : public OperatorTest {
     op_var_out(
         self, optional_dim_list, /*unbiased=*/true, /*keepdim=*/false, out);
     // clang-format off
-    EXPECT_TENSOR_CLOSE(out, tf_out.make(
+    expect_tensor_close_with_increased_tol(out, tf_out.make(
       {2, 3},
       {
         1.666667, 1.666667, 1.666667,
@@ -174,12 +187,14 @@ class OpVarOutTest : public OperatorTest {
     optional_dim_list = ArrayRef<int64_t>{dims_2, 2};
     op_var_out(
         self, optional_dim_list, /*unbiased=*/true, /*keepdim=*/true, out);
-    EXPECT_TENSOR_CLOSE(out, tf_out.make({1, 1, 4}, {56.0, 56.0, 56.0, 56.0}));
+    expect_tensor_close_with_increased_tol(
+        out, tf_out.make({1, 1, 4}, {56.0, 56.0, 56.0, 56.0}));
 
     out = tf_out.zeros({4});
     op_var_out(
         self, optional_dim_list, /*unbiased=*/true, /*keepdim=*/false, out);
-    EXPECT_TENSOR_CLOSE(out, tf_out.make({4}, {56.0, 56.0, 56.0, 56.0}));
+    expect_tensor_close_with_increased_tol(
+        out, tf_out.make({4}, {56.0, 56.0, 56.0, 56.0}));
 
     // dim list with negative dimensions should work
     out = tf_out.zeros({2, 1, 4});
@@ -188,7 +203,7 @@ class OpVarOutTest : public OperatorTest {
     op_var_out(
         self, optional_dim_list, /*unbiased=*/false, /*keepdim=*/true, out);
     // clang-format off
-    EXPECT_TENSOR_CLOSE(out, tf_out.make(
+    expect_tensor_close_with_increased_tol(out, tf_out.make(
       {2, 1, 4},
       {
         10.666667, 10.666667, 10.666667, 10.666667,
@@ -201,18 +216,19 @@ class OpVarOutTest : public OperatorTest {
     out = tf_out.zeros({1, 1, 1});
     optional<ArrayRef<int64_t>> null_dim_list;
     op_var_out(self, null_dim_list, /*unbiased=*/true, /*keepdim=*/true, out);
-    EXPECT_TENSOR_CLOSE(out, tf_out.make({1, 1, 1}, {50.0}));
+    expect_tensor_close_with_increased_tol(out, tf_out.make({1, 1, 1}, {50.0}));
 
     optional<ArrayRef<int64_t>> empty_dim_list{ArrayRef<int64_t>{}};
     op_var_out(self, empty_dim_list, /*unbiased=*/false, /*keepdim=*/true, out);
-    EXPECT_TENSOR_CLOSE(out, tf_out.make({1, 1, 1}, {47.916668}));
+    expect_tensor_close_with_increased_tol(
+        out, tf_out.make({1, 1, 1}, {47.916668}));
 
     out = tf_out.zeros({});
     op_var_out(self, null_dim_list, /*unbiased=*/false, /*keepdim=*/false, out);
-    EXPECT_TENSOR_CLOSE(out, tf_out.make({}, {47.916668}));
+    expect_tensor_close_with_increased_tol(out, tf_out.make({}, {47.916668}));
 
     op_var_out(self, empty_dim_list, /*unbiased=*/true, /*keepdim=*/false, out);
-    EXPECT_TENSOR_CLOSE(out, tf_out.make({}, {50.0}));
+    expect_tensor_close_with_increased_tol(out, tf_out.make({}, {50.0}));
   }
 };
 
@@ -227,6 +243,20 @@ class OpVarCorrectionOutTest : public OperatorTest {
     return torch::executor::aten::var_outf(
         context_, self, dim, correction, keepdim, out);
   }
+
+  template <ScalarType DTYPE>
+  void test_dtype() {
+    TensorFactory<DTYPE> tf;
+
+    Tensor x = tf.make({2, 3}, {4.9, 4.0, 5.6, 3.8, 4.9, 5.6});
+    Tensor expected = tf.make({2}, {0.72693, 0.93032});
+    optional<Scalar> correction(1.23);
+    Tensor out = tf.zeros({2});
+
+    op_var_correction_out(
+        x, ArrayRef<int64_t>{1}, correction, /*keepdim=*/false, out);
+    expect_tensor_close_with_increased_tol(out, expected);
+  }
 };
 
 TEST_F(OpVarOutTest, InvalidDimensionListDies) {
@@ -303,9 +333,9 @@ TEST_F(OpVarOutTest, AllFloatInputFloatOutputPasses) {
   test_var_out_dtype<ScalarType::INPUT_DTYPE, ScalarType::OUTPUT_DTYPE>();
 
 #define TEST_ENTRY(INPUT_CTYPE, INPUT_DTYPE) \
-  ET_FORALL_FLOAT_TYPES_WITH2(INPUT_CTYPE, INPUT_DTYPE, TEST_KERNEL);
+  ET_FORALL_FLOATHBF16_TYPES_WITH2(INPUT_CTYPE, INPUT_DTYPE, TEST_KERNEL);
 
-  ET_FORALL_FLOAT_TYPES(TEST_ENTRY);
+  ET_FORALL_FLOATHBF16_TYPES(TEST_ENTRY);
 #undef TEST_ENTRY
 #undef TEST_KERNEL
 }
@@ -387,14 +417,7 @@ TEST_F(OpVarOutTest, DynamicShapeUnbound) {
 }
 
 TEST_F(OpVarCorrectionOutTest, SmokeTest) {
-  TensorFactory<ScalarType::Float> tf;
-
-  Tensor x = tf.make({2, 3}, {4.9, 4.0, 5.6, 3.8, 4.9, 5.6});
-  Tensor expected = tf.make({2}, {0.72693, 0.93032});
-  optional<Scalar> correction(1.23);
-  Tensor out = tf.zeros({2});
-
-  op_var_correction_out(
-      x, ArrayRef<int64_t>{1}, correction, /*keepdim=*/false, out);
-  EXPECT_TENSOR_CLOSE(out, expected);
+#define TEST_ENTRY(ctype, dtype) test_dtype<ScalarType::dtype>();
+  ET_FORALL_FLOATHBF16_TYPES(TEST_ENTRY);
+#undef TEST_ENTRY
 }