chore: import upstream snapshot with attribution

paddle/phi/kernels/cpu/lookup_table_dequant_kernel.cc

@@ -0,0 +1,99 @@
+// Copyright (c) 2024 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 <string>
+#include <vector>
+
+#include "paddle/phi/core/kernel_registry.h"
+#include "paddle/phi/kernels/funcs/blas/blas.h"
+#include "paddle/phi/kernels/funcs/eigen/common.h"
+#include "paddle/phi/kernels/funcs/selected_rows_functor.h"
+
+namespace phi {
+
+template <typename T>
+void dequant(const unsigned char *in,
+             T *out,
+             float min,
+             float max,
+             int emb_size,
+             int pow_2_bits) {
+  float scale = (max - min) / pow_2_bits;
+  for (int i = 0; i < emb_size; ++i) {
+    T x = scale * static_cast<int>(in[i]) + min;
+    out[i] = x;
+  }
+}
+
+constexpr int64_t kNoPadding = -1;
+
+template <typename T, typename Context>
+void LookupTableDequantKernel(const Context &dev_ctx,
+                              const DenseTensor &w,
+                              const DenseTensor &ids_in,
+                              int64_t padding_idx,
+                              DenseTensor *out) {
+  auto *ids_t = &ids_in;  // int tensor
+  auto *output_t = out;   // float tensor
+
+  auto *ids = ids_t->data<int64_t>();
+  int64_t ids_numel = ids_t->numel();
+
+  auto *table_t = &w;
+  int64_t row_number = table_t->dims()[0];
+  int64_t quant_number = table_t->dims()[1];
+  int64_t row_width = (quant_number - 2) * 4;
+
+  auto *table = table_t->data<float>();
+  auto *output = dev_ctx.template Alloc<T>(output_t);
+  int pow_2_bits = static_cast<int>(pow(2, 8));
+  for (int64_t i = 0; i < ids_numel; ++i) {
+    if (padding_idx != kNoPadding && ids[i] == padding_idx) {
+      memset(output + i * row_width, 0, row_width * sizeof(T));
+    } else {
+      PADDLE_ENFORCE_LT(
+          ids[i],
+          row_number,
+          common::errors::InvalidArgument(
+              "Variable value (input) of OP(lookup_table_dequant) "
+              "expected >= 0 and < %ld, but got %ld. Please check input "
+              "value.",
+              row_number,
+              ids[i]));
+      PADDLE_ENFORCE_GE(
+          ids[i],
+          0,
+          common::errors::InvalidArgument(
+              "Variable value (input) of OP(lookup_table_dequant) "
+              "expected >= 0 and < %ld, but got %ld. Please check input "
+              "value.",
+              row_number,
+              ids[i]));
+      float min = *(table + ids[i] * quant_number);
+      float max = *(table + ids[i] * quant_number + 1);
+      int offset = ids[i] * quant_number + 2;
+      const unsigned char *tensor_buf =
+          reinterpret_cast<const unsigned char *>(table + offset);
+      dequant(
+          tensor_buf, output + i * row_width, min, max, row_width, pow_2_bits);
+    }
+  }
+}
+}  // namespace phi
+
+PD_REGISTER_KERNEL(lookup_table_dequant,
+                   CPU,
+                   ALL_LAYOUT,
+                   phi::LookupTableDequantKernel,
+                   float) {}