chore: import upstream snapshot with attribution

paddle/phi/kernels/cpu/masked_scatter_kernel.cc

@@ -0,0 +1,99 @@
+// Copyright (c) 2025 PaddlePaddle Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "paddle/phi/kernels/masked_scatter_kernel.h"
+
+#include "paddle/phi/core/kernel_registry.h"
+#include "paddle/phi/kernels/expand_kernel.h"
+#include "paddle/phi/kernels/funcs/common_infer_shape_functions.h"
+
+namespace phi {
+
+template <typename T, typename Context>
+void MaskedScatterKernel(const Context& dev_ctx,
+                         const DenseTensor& x,
+                         const DenseTensor& mask,
+                         const DenseTensor& value,
+                         DenseTensor* out) {
+  if (x.numel() == 0 || mask.numel() == 0) {
+    dev_ctx.template Alloc<T>(out);
+    return;
+  }
+
+  auto x_dims = x.dims();
+  auto mask_dims = mask.dims();
+  auto expanded_size =
+      vectorize(funcs::BroadcastTwoDims(x_dims, mask_dims, -1));
+  DDim expanded_dims = make_ddim(expanded_size);
+
+  DenseTensor mask_expand;
+  DenseTensor x_expand;
+
+  if (mask_dims != expanded_dims) {
+    ExpandKernel<bool, Context>(
+        dev_ctx, mask, IntArray(expanded_size), &mask_expand);
+  } else {
+    mask_expand = mask;
+  }
+
+  if (x_dims != expanded_dims) {
+    ExpandKernel<T, Context>(dev_ctx, x, IntArray(expanded_size), &x_expand);
+  } else {
+    x_expand = x;
+  }
+
+  out->Resize(expanded_dims);
+  auto* out_data = dev_ctx.template Alloc<T>(out);
+  auto* x_data = x_expand.data<T>();
+  auto* mask_data = mask_expand.data<bool>();
+  auto* value_data = value.data<T>();
+  int64_t total = x_expand.numel();
+  int64_t value_numel = value.numel();
+
+  int64_t count = 0;
+  for (int64_t i = 0; i < total; i++) {
+    if (mask_data[i]) {
+      PADDLE_ENFORCE_LT(
+          count,
+          value_numel,
+          common::errors::InvalidArgument(
+              "Number of True values in mask (%d) exceeds the number of "
+              "elements in value (%d).",
+              count + 1,
+              value_numel));
+      out_data[i] = value_data[count];
+      count++;
+    } else {
+      out_data[i] = x_data[i];
+    }
+  }
+}
+
+}  // namespace phi
+
+PD_REGISTER_KERNEL(masked_scatter,
+                   CPU,
+                   ALL_LAYOUT,
+                   phi::MaskedScatterKernel,
+                   float,
+                   double,
+                   int,
+                   int64_t,
+                   int16_t,
+                   int8_t,
+                   uint8_t,
+                   phi::float16,
+                   phi::bfloat16) {
+  kernel->InputAt(1).SetDataType(phi::DataType::BOOL);
+}