add softmax_switch for softmax_with_cross_entropy_op, test=develop (#31428)

* add softmax_switch for softmax_with_cross_entropy_op, test=develop

* delete using EigenMatrix in softmax_with_cross_entropy_op.h, test=develop

* add REGISTER_OP_VERSION for softmax_switch attr of softmax_with_cross_entropy_op, test=develop

paddle/fluid/operators/softmax_with_cross_entropy_op.cc

@@ -17,6 +17,7 @@ limitations under the License. */
 #include <string>
 #include <unordered_map>
 #include <vector>
+#include "paddle/fluid/framework/op_version_registry.h"
 
 namespace paddle {
 namespace operators {
@@ -53,6 +54,10 @@ class SoftmaxWithCrossEntropyOpMaker
         "(bool, default: false), A flag to indicate whether to interpretant "
         "the given labels as soft labels.")
         .SetDefault(false);
+    AddAttr<bool>(
+        "softmax_switch",
+        "(bool, default: true), A flag to indicate whether to do softmax ")
+        .SetDefault(true);
     AddAttr<bool>(
         "numeric_stable_mode",
         "(bool, default: true), A flag to indicate whether to use more "
@@ -312,3 +317,10 @@ REGISTER_OP_CPU_KERNEL(softmax_with_cross_entropy,
 REGISTER_OP_CPU_KERNEL(softmax_with_cross_entropy_grad,
                        ops::SoftmaxWithCrossEntropyGradKernel<float>,
                        ops::SoftmaxWithCrossEntropyGradKernel<double>);
+REGISTER_OP_VERSION(softmax_with_cross_entropy)
+    .AddCheckpoint(
+        R"ROC(
+              Add a new attribute [softmax_switch] )ROC",
+        paddle::framework::compatible::OpVersionDesc().NewAttr(
+            "softmax_switch", "A flag to indicate whether to do softmax",
+            true));

paddle/fluid/operators/softmax_with_cross_entropy_op.cu

@@ -72,6 +72,57 @@ __global__ void SoftCrossEntropyGradientKernel(T* logit_grad,
   }
 }
 
+template <typename T>
+__global__ void SoftLabelCrossEntropyGradientKernel(T* logit_grad,
+                                                    const T* loss_grad,
+                                                    const T* labels,
+                                                    const int n, const int d,
+                                                    const int remain) {
+  int ids = blockIdx.x * blockDim.x + threadIdx.x;
+  if (ids < n * d) {
+    int idx_n = ids / d;
+    int idx_remain = ids % remain;
+    int idx_loss = idx_n * remain + idx_remain;
+    logit_grad[ids] = loss_grad[idx_loss] * (-labels[ids] / logit_grad[ids]);
+  }
+}
+
+template <typename T>
+__global__ void HardLabelCrossEntropyGradientKernel(T* logit_grad,
+                                                    const int64_t* labels,
+                                                    const int n, const int d,
+                                                    const int remain,
+                                                    const int ignore_index) {
+  CUDA_KERNEL_LOOP(index, n * remain) {
+    int idx_n = index / remain;
+    int idx_remain = index % remain;
+    int tmp = labels[index];
+    int idx = idx_n * d + tmp * remain + idx_remain;
+    if (ignore_index != tmp) {
+      logit_grad[idx] = -static_cast<T>(1.) / logit_grad[idx];
+    }
+  }
+}
+
+template <typename T>
+__global__ void ScaleCrossEntropyGradient(T* logit_grad, const T* loss_grad,
+                                          const int num, const int d,
+                                          const int remain,
+                                          const int64_t* labels,
+                                          const int ignore_index) {
+  CUDA_KERNEL_LOOP(index, num) {
+    int idx_n = index / d;
+    int idx_remain = index % remain;
+    int idx_lbl = idx_n * remain + idx_remain;
+    int k = (index % d) / remain;
+    if (labels[idx_lbl] == ignore_index || labels[idx_lbl] != k) {
+      logit_grad[index] = static_cast<T>(0.);
+    } else {
+      logit_grad[index] *= loss_grad[idx_lbl];
+    }
+  }
+}
+
 }  // namespace
 
 static __device__ __forceinline__ platform::float16 exp_on_device(
@@ -308,6 +359,160 @@ static __global__ void RowReductionForSoftmaxAndCrossEntropy(
   if (threadIdx.x == 0) loss_data[blockIdx.x] = loss;
 }
 
+// Make sure that BlockDim <= axis_dim
+template <typename T, int BlockDim>
+static __global__ void RowReductionForCrossEntropy(const T* logits_data,
+                                                   const T* labels_data,
+                                                   T* loss_data, int d,
+                                                   int axis_dim) {
+  __shared__ BlockReduceTempStorage<T, BlockDim> temp_storage;
+
+  // logits, softmax, labels data view as [n, axis_dim, remain]
+  // loss_data view as [n, 1, remain]
+  // blockDim = n * remain, split blockIdx to idx_n and idx_remain
+  int remain = d / axis_dim;
+  int idx_n = blockIdx.x / remain;
+  int idx_remain = blockIdx.x % remain;
+  int beg_idx = idx_n * d + threadIdx.x * remain + idx_remain;
+  int end_idx = (idx_n + 1) * d;
+
+  // log_diff_max_sum shares memory with loss
+  auto block_log_diff_max_sum = loss_data[blockIdx.x];
+  auto tmp = log_on_device(logits_data[beg_idx]);  // when not with softmax,
+                                                   // softmax is stored in
+                                                   // logits_data
+  auto loss = -labels_data[beg_idx] * tmp;
+  int step = BlockDim * remain;
+  beg_idx += step;
+  while (beg_idx < end_idx) {
+    tmp = log_on_device(logits_data[beg_idx]);  // when not with softmax,
+                                                // softmax is stored in
+                                                // logits_data
+    loss -= (labels_data[beg_idx] * tmp);
+    beg_idx += step;
+  }
+
+  loss = BlockReduce<T, BlockDim>(temp_storage).Reduce(loss, cub::Sum());
+  if (threadIdx.x == 0) loss_data[blockIdx.x] = loss;
+}
+
+template <typename T>
+struct HardLabelCrossEntropyFunctor {
+ public:
+  HardLabelCrossEntropyFunctor(const int64_t* labels, T* loss,
+                               const T* logits_data, int d, int axis_dim)
+      : labels_(labels),
+        loss_(loss),
+        logits_data_(logits_data),
+        d_(d),
+        axis_dim_(axis_dim) {}
+
+  __device__ void operator()(int idx) const {
+    // logits view as [n, axis_dim, remain], where d = axis_dim * remain
+    int remain = d_ / axis_dim_;
+    int idx_n = idx / d_;
+    int idx_axis = (idx % d_) / remain;
+    int idx_remain = idx % remain;
+    // labels, loss view as [n, remain]
+    int idx_lbl = idx_n * remain + idx_remain;
+    // It also would ignore labels not in range(class_num).
+    if (idx_axis != labels_[idx_lbl]) {
+    } else {
+      loss_[idx_lbl] = -log_on_device(logits_data_[idx]);
+    }
+  }
+
+ private:
+  const int64_t* labels_;
+  T* loss_;
+  const T* logits_data_;
+  int d_;
+  int axis_dim_;
+};
+
+template <typename T>
+struct HardLabelCrossEntropyFunctorWithIgnoreIdx {
+ public:
+  HardLabelCrossEntropyFunctorWithIgnoreIdx(const int64_t* labels, T* loss,
+                                            const T* logits_data, int d,
+                                            int axis_dim, int ignore_idx)
+      : labels_(labels),
+        loss_(loss),
+        logits_data_(logits_data),
+        d_(d),
+        axis_dim_(axis_dim),
+        ignore_idx_(ignore_idx) {}
+
+  __device__ void operator()(int idx) const {
+    // logits view as [n, axis_dim, remain], where d = axis_dim * remain
+    int remain = d_ / axis_dim_;
+    int idx_n = idx / d_;
+    int idx_axis = (idx % d_) / remain;
+    int idx_remain = idx % remain;
+    // labels, loss view as [n, remain]
+    int idx_lbl = idx_n * remain + idx_remain;
+
+    if (idx_axis == ignore_idx_) {
+      loss_[idx_lbl] = 0;
+      return;
+    }
+
+    if (idx_axis == labels_[idx_lbl]) {
+      loss_[idx_lbl] = -log_on_device(logits_data_[idx]);
+    }
+  }
+
+ private:
+  const int64_t* labels_;
+  T* loss_;
+  const T* logits_data_;
+  int d_;
+  int axis_dim_;
+  int ignore_idx_;
+};
+
+template <typename T>
+static void HardLabelCrossEntropy(const platform::CUDADeviceContext& ctx,
+                                  const T* logits_data,
+                                  const int64_t* labels_data, T* loss_data,
+                                  int n, int d, int axis_dim, int ignore_idx) {
+  constexpr int kMaxBlockDim = 512;
+  int block_dim = axis_dim >= kMaxBlockDim
+                      ? kMaxBlockDim
+                      : (1 << static_cast<int>(std::log2(axis_dim)));
+  int grid_dim = n * d / axis_dim;
+  auto stream = ctx.stream();
+
+#define CALL_HARD_LABEL_CROSS_ENTROPY_FUSED_KERNEL(BlockDim)                \
+  case BlockDim: {                                                          \
+    platform::ForRange<platform::CUDADeviceContext> for_range(ctx, n* d);   \
+    if (ignore_idx >= 0 && ignore_idx < axis_dim) {                         \
+      for_range(HardLabelCrossEntropyFunctorWithIgnoreIdx<T>(               \
+          labels_data, loss_data, logits_data, d, axis_dim, ignore_idx));   \
+    } else {                                                                \
+      for_range(HardLabelCrossEntropyFunctor<T>(labels_data, loss_data,     \
+                                                logits_data, d, axis_dim)); \
+    }                                                                       \
+  } break
+
+  switch (block_dim) {
+    CALL_HARD_LABEL_CROSS_ENTROPY_FUSED_KERNEL(512);
+    CALL_HARD_LABEL_CROSS_ENTROPY_FUSED_KERNEL(256);
+    CALL_HARD_LABEL_CROSS_ENTROPY_FUSED_KERNEL(128);
+    CALL_HARD_LABEL_CROSS_ENTROPY_FUSED_KERNEL(64);
+    CALL_HARD_LABEL_CROSS_ENTROPY_FUSED_KERNEL(32);
+    CALL_HARD_LABEL_CROSS_ENTROPY_FUSED_KERNEL(16);
+    CALL_HARD_LABEL_CROSS_ENTROPY_FUSED_KERNEL(8);
+    CALL_HARD_LABEL_CROSS_ENTROPY_FUSED_KERNEL(4);
+    CALL_HARD_LABEL_CROSS_ENTROPY_FUSED_KERNEL(2);
+    default:
+      PADDLE_THROW(platform::errors::Unavailable(
+          "Block Dimension must be 2^n in softmax_with_cross_entropy_op."));
+      break;
+  }
+#undef CALL_HARD_LABEL_SOFTMAX_WITH_CROSS_ENTROPY_FUSED_KERNEL
+}
+
 template <typename T>
 struct HardLabelSoftmaxWithCrossEntropyFunctor {
  public:
@@ -523,6 +728,43 @@ static void SoftmaxWithCrossEntropyFusedKernel(
 #undef CALL_SOFTMAX_WITH_CROSS_ENTROPY_FUSED_KERNEL
 }
 
+// not with softmax
+template <typename T>
+static void CrossEntropyFusedKernel(const T* logits_data, const T* labels_data,
+                                    T* loss_data, int n, int d, int axis_dim,
+                                    cudaStream_t stream) {
+  constexpr int kMaxBlockDim = 512;
+  int block_dim = axis_dim >= kMaxBlockDim
+                      ? kMaxBlockDim
+                      : (1 << static_cast<int>(std::log2(axis_dim)));
+  int grid_dim = n * d / axis_dim;
+
+#define CALL_SOFTMAX_WITH_CROSS_ENTROPY_FUSED_KERNEL(BlockDim)                \
+  case BlockDim:                                                              \
+    RowReductionForCrossEntropy<T,                                            \
+                                BlockDim><<<grid_dim, BlockDim, 0, stream>>>( \
+        logits_data, labels_data, loss_data, d, axis_dim);                    \
+    break
+
+  switch (block_dim) {
+    CALL_SOFTMAX_WITH_CROSS_ENTROPY_FUSED_KERNEL(512);
+    CALL_SOFTMAX_WITH_CROSS_ENTROPY_FUSED_KERNEL(256);
+    CALL_SOFTMAX_WITH_CROSS_ENTROPY_FUSED_KERNEL(128);
+    CALL_SOFTMAX_WITH_CROSS_ENTROPY_FUSED_KERNEL(64);
+    CALL_SOFTMAX_WITH_CROSS_ENTROPY_FUSED_KERNEL(32);
+    CALL_SOFTMAX_WITH_CROSS_ENTROPY_FUSED_KERNEL(16);
+    CALL_SOFTMAX_WITH_CROSS_ENTROPY_FUSED_KERNEL(8);
+    CALL_SOFTMAX_WITH_CROSS_ENTROPY_FUSED_KERNEL(4);
+    CALL_SOFTMAX_WITH_CROSS_ENTROPY_FUSED_KERNEL(2);
+    default:
+      PADDLE_THROW(platform::errors::Unavailable(
+          "Block Dimension must be 2^n in softmax_with_cross_entropy_op."));
+      break;
+  }
+
+#undef CALL_SOFTMAX_WITH_CROSS_ENTROPY_FUSED_KERNEL
+}
+
 template <typename T>
 class SoftmaxWithCrossEntropyCUDAKernel : public framework::OpKernel<T> {
  public:
@@ -531,6 +773,73 @@ class SoftmaxWithCrossEntropyCUDAKernel : public framework::OpKernel<T> {
         platform::is_gpu_place(context.GetPlace()), true,
         platform::errors::Unavailable("softmax_with_cross_entropy operator's "
                                       "CUDA kernel only runs on GPU device."));
+    const bool softmax_switch = context.Attr<bool>("softmax_switch");
+
+    // do not with softmax op, and input is softmax
+    if (!softmax_switch) {
+      const Tensor* softmax = context.Input<Tensor>("Logits");
+      const Tensor* labels = context.Input<Tensor>("Label");
+      Tensor* softmax_out = context.Output<Tensor>("Softmax");
+      Tensor* loss = context.Output<Tensor>("Loss");
+
+      const int rank = softmax->dims().size();
+      const int axis = CanonicalAxis(context.Attr<int>("axis"), rank);
+      int axis_dim = softmax->dims()[axis];
+
+      const int n = SizeToAxis(axis, softmax->dims());
+      const int d = SizeFromAxis(axis, softmax->dims());
+
+      auto* softmax_out_data = softmax_out->mutable_data<T>(context.GetPlace());
+      auto* loss_data = loss->mutable_data<T>(context.GetPlace());
+
+      if (axis_dim == 1) {
+        math::SetConstant<platform::CUDADeviceContext, T> set_constant;
+        set_constant(context.cuda_device_context(), softmax_out,
+                     static_cast<T>(1));
+        set_constant(context.cuda_device_context(), loss, static_cast<T>(0));
+        return;
+      }
+
+      auto soft_label = context.Attr<bool>("soft_label");
+      auto ignore_index = context.Attr<int>("ignore_index");
+
+      Tensor softmax_2d, labels_2d, loss_2d, softmax_out_2d;
+      softmax_2d.ShareDataWith(*softmax).Resize({n, d});
+      labels_2d.ShareDataWith(*labels).Resize({n, labels->numel() / n});
+      loss_2d.ShareDataWith(*loss).Resize({n, 1});
+      softmax_out_2d.ShareDataWith(*softmax_out).Resize({n, d});
+
+      // math::CrossEntropyFunctor support axis is the last
+      if (axis == -1) {
+        math::CrossEntropyFunctor<platform::CUDADeviceContext, T>()(
+            context.cuda_device_context(), &loss_2d, &softmax_2d, &labels_2d,
+            soft_label, ignore_index, axis_dim);
+        return;
+      }
+
+      // if axis is not the last, we need a new impliment
+      if (soft_label) {
+        auto* logits_data = softmax->data<T>();
+        auto* labels_data = labels->data<T>();
+        CrossEntropyFusedKernel(logits_data, labels_data, loss_data, n, d,
+                                axis_dim,
+                                context.cuda_device_context().stream());
+      } else {  // HardLabel
+        auto* logits_data = softmax->data<T>();
+        auto* labels_data = labels->data<int64_t>();
+        HardLabelCrossEntropy<T>(context.cuda_device_context(), logits_data,
+                                 labels_data, loss_data, n, d, axis_dim,
+                                 ignore_index);
+      }
+
+      // cause of input is softmax
+      // copy to output softmax, directly
+      framework::TensorCopy(*softmax, context.GetPlace(),
+                            context.device_context(), softmax_out);
+
+      return;
+    }
+
     const Tensor* logits = context.Input<Tensor>("Logits");
     const Tensor* labels = context.Input<Tensor>("Label");
     Tensor* softmax = context.Output<Tensor>("Softmax");
@@ -617,6 +926,34 @@ class SoftmaxWithCrossEntropyGradCUDAKernel : public framework::OpKernel<T> {
     int block = 512;
     auto stream = context.cuda_device_context().stream();
     auto ignore_index = context.Attr<int>("ignore_index");
+    auto softmax_switch = context.Attr<bool>("softmax_switch");
+
+    // do not with softmax op, and input is softmax
+    if (!softmax_switch) {
+      if (context.Attr<bool>("soft_label")) {
+        int grid = (n * d + block - 1) / block;
+        const T* label_data = labels->data<T>();
+        SoftLabelCrossEntropyGradientKernel<T><<<grid, block, 0, stream>>>(
+            logit_grad_data, loss_grad_data, label_data, n, d, remain);
+      } else {
+        Tensor logits_grad_2d;
+        logits_grad_2d.ShareDataWith(*logit_grad).Resize({n, d});
+        int grid = (n * remain + block - 1) / block;
+        const int64_t* label_data = labels->data<int64_t>();
+        HardLabelCrossEntropyGradientKernel<T><<<grid, block, 0, stream>>>(
+            logit_grad_data, label_data, n, d, remain, ignore_index);
+        int num = n * d;
+        grid = (num + block - 1) / block;
+        ScaleCrossEntropyGradient<T><<<grid, block, 0, stream>>>(
+            logit_grad_data, loss_grad_data, num, d, remain, label_data,
+            ignore_index);
+      }
+
+      return;
+    }
+
+    // with softmax, continue
+
     if (context.Attr<bool>("soft_label")) {
       int64_t grid = (n * d + block - 1) / block;
       const T* label_data = labels->data<T>();

paddle/fluid/operators/softmax_with_cross_entropy_op.h

@@ -31,6 +31,46 @@ class SoftmaxWithCrossEntropyKernel : public framework::OpKernel<T> {
     PADDLE_ENFORCE_EQ(
         platform::is_cpu_place(context.GetPlace()), true,
         platform::errors::Unimplemented("This kernel only runs on CPU."));
+    const bool softmax_switch = context.Attr<bool>("softmax_switch");
+
+    // do not with softmax op, and input is softmax
+    if (!softmax_switch) {
+      const Tensor* softmax = context.Input<Tensor>("Logits");
+      const Tensor* labels = context.Input<Tensor>("Label");
+      Tensor* softmax_out = context.Output<Tensor>("Softmax");
+      Tensor* loss = context.Output<Tensor>("Loss");
+      const bool soft_label = context.Attr<bool>("soft_label");
+      const int rank = softmax->dims().size();
+      const int axis = CanonicalAxis(context.Attr<int>("axis"), rank);
+      int axis_dim = softmax->dims()[axis];
+
+      softmax_out->mutable_data<T>(context.GetPlace());
+      loss->mutable_data<T>(context.GetPlace());
+
+      const int n = SizeToAxis(axis, softmax->dims());
+      const int d = SizeFromAxis(axis, softmax->dims());
+
+      Tensor softmax_2d, labels_2d, loss_2d, softmax_out_2d;
+      softmax_2d.ShareDataWith(*softmax).Resize({n, d});
+      labels_2d.ShareDataWith(*labels).Resize({n, labels->numel() / n});
+      loss_2d.ShareDataWith(*loss).Resize({n, d / axis_dim});
+      softmax_out_2d.ShareDataWith(*softmax_out).Resize({n, d});
+
+      auto& dev_ctx =
+          context.template device_context<platform::CPUDeviceContext>();
+
+      math::CrossEntropyFunctor<platform::CPUDeviceContext, T>()(
+          dev_ctx, &loss_2d, &softmax_2d, &labels_2d, soft_label,
+          context.Attr<int>("ignore_index"), axis_dim);
+
+      // cause of input is softmax
+      // copy to output softmax, directly
+      framework::TensorCopy(*softmax, context.GetPlace(),
+                            context.device_context(), softmax_out);
+
+      return;
+    }
+
     const Tensor* logits = context.Input<Tensor>("Logits");
     const Tensor* labels = context.Input<Tensor>("Label");
     Tensor* softmax = context.Output<Tensor>("Softmax");
@@ -73,7 +113,9 @@ class SoftmaxWithCrossEntropyGradKernel : public framework::OpKernel<T> {
         context.Output<Tensor>(framework::GradVarName("Logits"));
 
     const Tensor* softmax = context.Input<Tensor>("Softmax");
-    if (logit_grad != softmax) {
+    const bool softmax_switch = context.Attr<bool>("softmax_switch");
+
+    if (logit_grad != softmax || !softmax_switch) {
       framework::TensorCopy(*softmax, context.GetPlace(),
                             context.device_context(), logit_grad);
     }
@@ -96,28 +138,94 @@ class SoftmaxWithCrossEntropyGradKernel : public framework::OpKernel<T> {
     auto logit_grad_mat = framework::EigenMatrix<T>::From(logit_grad_2d);
     auto& place = *context.template device_context<platform::CPUDeviceContext>()
                        .eigen_device();
+    if (!softmax_switch) {
+      // softmax_switch step1
+      if (soft_label) {
+        auto lbl_mat = framework::EigenMatrix<T>::From(labels_2d);
+        logit_grad_mat.device(place) =
+            (-lbl_mat / logit_grad_mat);  // for each sample ,i  is sample id
+        logit_grad_mat.device(place) =
+            out_grad_mat.broadcast(Eigen::DSizes<int, 2>(1, axis_dim)) *
+            logit_grad_mat;
+      }
+      // softmax_switch step2
+      else {
+        const int64_t* label_data = labels->data<int64_t>();
+        T* logit_grad_data = logit_grad->data<T>();
+        const T* out_grad_data = out_grad->data<T>();
+        const int remain = d / axis_dim;
+        for (int i = 0; i < n; ++i) {         // for each sample_1_dim
+          for (int j = 0; j < remain; j++) {  // for each sample_other_dims
+            int idx = i * remain + j;  // this sample's label_idx. for 1d case,
+                                       // remain=1 and j=0, so, idx = i
+            if (label_data[idx] == ignore_index) {
+              for (int k = 0; k < axis_dim; ++k) {  // for each class id's label
+                logit_grad_data[i * d + k * remain + j] = 0;
+              }
+            } else {
+              // only for this sample's label_idx, the label is 1, others is 0,
+              // so, only compute this label_idx's class
+              logit_grad_data[i * d + label_data[idx] * remain + j] =
+                  (-1 / logit_grad_data[i * d + label_data[idx] * remain + j]) *
+                  out_grad_data[idx];
+              for (int k = 0; k < axis_dim; ++k) {  // for each class id's label
+                if (k !=
+                    label_data[idx]) {  // label_data[idx]: this sample's label
+                  logit_grad_data[i * d + k * remain + j] = 0;
+                }
+              }
+            }
+          }
+        }
+      }
+      return;
+    }
+
+    // for softmax_switch=False, continue
+
     if (soft_label) {
+      // when soft_label = True, ignore_index is not supported
       auto lbl_mat = framework::EigenMatrix<T>::From(labels_2d);
       logit_grad_mat.device(place) =
           out_grad_mat.broadcast(Eigen::DSizes<int, 2>(1, axis_dim)) *
-          (logit_grad_mat - lbl_mat);
+          (logit_grad_mat - lbl_mat);  // for each sample ,i  is sample id
+      //         1) compute dy/dx by p_j - y_j or P-Y, where j is class id,
+      //            P=logit_grad_mat[i] is all class's probs, Y=lbl_mat[i] is
+      //            all class's labels
+      //         2) compute dy * dy/dx by   Chain rule, dy=out_grad_mat[i]
+      // for high dims, e.g. (n,c) or (n,d1,...,dm, c), compute grad by matrix
+      // operation
+
     } else {
       logit_grad_mat.device(place) =
-          logit_grad_mat *
+          logit_grad_mat *  // element_wise multiply
           out_grad_mat.broadcast(Eigen::DSizes<int, 2>(1, axis_dim));
 
       const int64_t* label_data = labels->data<int64_t>();
       T* logit_grad_data = logit_grad->data<T>();
       const T* out_grad_data = out_grad->data<T>();
       const int remain = d / axis_dim;
-      for (int i = 0; i < n; ++i) {
-        for (int j = 0; j < remain; j++) {
-          int idx = i * remain + j;
+      for (int i = 0; i < n; ++i) {         // for each sample_1_dim
+        for (int j = 0; j < remain; j++) {  // for each sample_other_dims
+          int idx = i * remain + j;  // this sample's label_idx. for 1d case,
+                                     // remain=1 and j=0, so, idx = i
           if (label_data[idx] == ignore_index) {
-            for (int k = 0; k < axis_dim; ++k) {
+            for (int k = 0; k < axis_dim; ++k) {  // for each class id's label
               logit_grad_data[i * d + k * remain + j] = 0;
             }
           } else {
+            // only for this sample's label_idx, the label is 1, others is 0,
+            // so, only compute this label_idx's class
+            // for 1d case, remain=1 and j=0, so, [i * d + label_data[idx] *
+            // remain + j] = [i * d + label_data[idx]]
+            // let idx_x = i * d + label_data[idx] * remain + j,
+            //   logit_grad_data[idx_x] = logit_grad_data[idx_x] -
+            //   out_grad_data[idx]
+            // note: logit_grad_mat = logit_grad_mat * out_grad_mat
+            // so: logit_grad_data[idx_x] =  (logit_grad_data[idx_x] - 1) *
+            // out_grad_data[idx]
+            // means:           dy/dp * dy=   ( p - y ) * dy
+
             logit_grad_data[i * d + label_data[idx] * remain + j] -=
                 out_grad_data[idx];
           }

python/paddle/fluid/tests/unittests/test_softmax_with_cross_entropy_op.py

@@ -56,6 +56,7 @@ class TestSoftmaxWithCrossEntropyOp(OpTest):
         self.axis = -1
         self.ignore_index = -1
         self.shape = [41, 37]
+        self.softmax_switch = True
 
     def setUp(self):
         self.initParams()
@@ -76,7 +77,11 @@ class TestSoftmaxWithCrossEntropyOp(OpTest):
         loss = cross_entropy(softmax, labels, self.soft_label, self.axis,
                              self.ignore_index)
 
-        self.inputs = {"Logits": logits, "Label": labels}
+        if self.softmax_switch == False:
+            self.inputs = {"Logits": softmax, "Label": labels}
+        else:
+            self.inputs = {"Logits": logits, "Label": labels}
+
         self.outputs = {
             "Softmax": softmax.astype(self.dtype),
             "Loss": loss.astype(self.dtype)
@@ -85,6 +90,7 @@ class TestSoftmaxWithCrossEntropyOp(OpTest):
             "numeric_stable_mode": self.numeric_stable_mode,
             "soft_label": self.soft_label,
             "ignore_index": self.ignore_index,
+            "softmax_switch": self.softmax_switch,
         }
 
         if self.axis != -1:
@@ -98,7 +104,215 @@ class TestSoftmaxWithCrossEntropyOp(OpTest):
             # HIP will have accuracy fail when using float32 in CPU place
             self.check_grad(["Logits"], "Loss", max_relative_error=5e-1)
         else:
-            self.check_grad(["Logits"], "Loss", max_relative_error=5e-5)
+            self.check_grad(["Logits"], "Loss", numeric_grad_delta=0.001)
+
+
+class TestSoftmaxWithCrossEntropyOp_NotWithSoftmax_SoftLabel_1D(
+        TestSoftmaxWithCrossEntropyOp):
+    def initParams(self):
+        self.op_type = "softmax_with_cross_entropy"
+        self.numeric_stable_mode = True
+        self.soft_label = True
+        self.shape = [13, 8]
+        self.axis = -1
+        self.ignore_index = -1
+        self.dtype = np.float64
+        self.softmax_switch = False  #default is true, means "with softmax"
+
+
+class TestSoftmaxWithCrossEntropyOp_NotWithSoftmax_HardLabel_1D(
+        TestSoftmaxWithCrossEntropyOp):
+    def initParams(self):
+        self.op_type = "softmax_with_cross_entropy"
+        self.numeric_stable_mode = True
+        self.soft_label = False
+        self.shape = [13, 8]
+        self.axis = -1
+        self.ignore_index = -1
+        self.dtype = np.float64
+        self.softmax_switch = False  #default is true, means "with softmax"
+
+
+##############################################################################
+#NotWithSoftmax_SoftLabel_2D start
+##############################################################################
+class TestSoftmaxWithCrossEntropyOp_NotWithSoftmax_SoftLabel_2D(
+        TestSoftmaxWithCrossEntropyOp):
+    def initParams(self):
+        self.op_type = "softmax_with_cross_entropy"
+        self.numeric_stable_mode = True
+        self.soft_label = True
+        self.shape = [3, 5, 7, 11]
+        self.axis = -1
+        self.ignore_index = -1
+        self.dtype = np.float64
+        self.softmax_switch = False  #default is true, means "with softmax"
+
+
+class TestSoftmaxWithCrossEntropyOp_NotWithSoftmax_SoftLabel_2D_Axis2(
+        TestSoftmaxWithCrossEntropyOp):
+    def initParams(self):
+        self.op_type = "softmax_with_cross_entropy"
+        self.numeric_stable_mode = True
+        self.soft_label = True
+        self.dtype = np.float64
+        self.axis = 1
+        self.ignore_index = -1
+        self.shape = [3, 5, 7, 11]
+        self.softmax_switch = False  #default is true, means "with softmax"
+
+
+class TestSoftmaxWithCrossEntropyOp_NotWithSoftmax_SoftLabel_2D_Axis3(
+        TestSoftmaxWithCrossEntropyOp):
+    def initParams(self):
+        self.op_type = "softmax_with_cross_entropy"
+        self.numeric_stable_mode = True
+        self.soft_label = True
+        self.dtype = np.float64
+        self.axis = 2
+        self.ignore_index = -1
+        self.shape = [3, 5, 7, 11]
+        self.softmax_switch = False  #default is true, means "with softmax"
+
+
+class TestSoftmaxWithCrossEntropyOp_NotWithSoftmax_SoftLabel_2D_Axis4(
+        TestSoftmaxWithCrossEntropyOp):
+    def initParams(self):
+        self.op_type = "softmax_with_cross_entropy"
+        self.numeric_stable_mode = True
+        self.soft_label = True
+        self.dtype = np.float64
+        self.axis = 3
+        self.ignore_index = -1
+        self.shape = [3, 5, 7, 11]
+        self.softmax_switch = False  #default is true, means "with softmax"
+
+
+##############################################################################
+#NotWithSoftmax_SoftLabel_2D end
+##############################################################################
+
+##############################################################################
+#NotWithSoftmax_HardLabel_2D start
+##############################################################################
+
+
+class TestSoftmaxWithCrossEntropyOp_NotWithSoftmax_HardLabel_2D(
+        TestSoftmaxWithCrossEntropyOp):
+    def initParams(self):
+        self.op_type = "softmax_with_cross_entropy"
+        self.numeric_stable_mode = True
+        self.soft_label = False
+        self.shape = [3, 5, 7, 11]
+        self.axis = -1
+        self.ignore_index = -1
+        self.dtype = np.float64
+        self.softmax_switch = False  #default is true, means "with softmax"
+
+
+class TestSoftmaxWithCrossEntropyOp_NotWithSoftmax_HardLabel_2D_Axis2(
+        TestSoftmaxWithCrossEntropyOp):
+    def initParams(self):
+        self.op_type = "softmax_with_cross_entropy"
+        self.numeric_stable_mode = True
+        self.soft_label = False
+        self.dtype = np.float64
+        self.axis = 1
+        self.ignore_index = -1
+        self.shape = [3, 5, 7, 11]
+        self.softmax_switch = False  #default is true, means "with softmax"
+
+
+class TestSoftmaxWithCrossEntropyOp_NotWithSoftmax_HardLabel_2D_Axis3(
+        TestSoftmaxWithCrossEntropyOp):
+    def initParams(self):
+        self.op_type = "softmax_with_cross_entropy"
+        self.numeric_stable_mode = True
+        self.soft_label = False
+        self.dtype = np.float64
+        self.axis = 2
+        self.ignore_index = -1
+        self.shape = [3, 5, 7, 11]
+        self.softmax_switch = False  #default is true, means "with softmax"
+
+
+class TestSoftmaxWithCrossEntropyOp_NotWithSoftmax_HardLabel_2D_Axis4(
+        TestSoftmaxWithCrossEntropyOp):
+    def initParams(self):
+        self.op_type = "softmax_with_cross_entropy"
+        self.numeric_stable_mode = True
+        self.soft_label = False
+        self.dtype = np.float64
+        self.axis = 3
+        self.ignore_index = -1
+        self.shape = [3, 5, 7, 11]
+        self.softmax_switch = False  #default is true, means "with softmax"
+
+
+##############################################################################
+#NotWithSoftmax_HardLabel_2D end
+##############################################################################
+
+##############################################################################
+#NotWithSoftmax_HardLabel_2D_Ignore start
+##############################################################################
+
+
+class TestSoftmaxWithCrossEntropyOp_NotWithSoftmax_HardLabel_Ignore(
+        TestSoftmaxWithCrossEntropyOp):
+    def initParams(self):
+        self.op_type = "softmax_with_cross_entropy"
+        self.numeric_stable_mode = False
+        self.soft_label = False
+        self.shape = [13, 8]
+        self.axis = -1
+        self.ignore_index = 2
+        self.dtype = np.float64
+        self.softmax_switch = False  #default is true, means "with softmax"
+
+
+class TestSoftmaxWithCrossEntropyOp_NotWithSoftmax_HardLabel_Ignore_Axis(
+        TestSoftmaxWithCrossEntropyOp):
+    def initParams(self):
+        self.op_type = "softmax_with_cross_entropy"
+        self.numeric_stable_mode = False
+        self.soft_label = False
+        self.shape = [13, 8]
+        self.axis = 1
+        self.ignore_index = 2
+        self.dtype = np.float64
+        self.softmax_switch = False  #default is true, means "with softmax"
+
+
+class TestSoftmaxWithCrossEntropyOp_NotWithSoftmax_HardLabel_2D_Ignore(
+        TestSoftmaxWithCrossEntropyOp):
+    def initParams(self):
+        self.op_type = "softmax_with_cross_entropy"
+        self.numeric_stable_mode = True
+        self.soft_label = False
+        self.shape = [3, 5, 7, 11]
+        self.axis = -1
+        self.ignore_index = 2
+        self.dtype = np.float64
+        self.softmax_switch = False  #default is true, means "with softmax"
+
+
+class TestSoftmaxWithCrossEntropyOp_NotWithSoftmax_HardLabel_2D_Ignore_Axis3(
+        TestSoftmaxWithCrossEntropyOp):
+    def initParams(self):
+        self.op_type = "softmax_with_cross_entropy"
+        self.numeric_stable_mode = True
+        self.soft_label = False
+        self.dtype = np.float64
+        self.axis = 2
+        self.ignore_index = 2
+        self.shape = [3, 5, 7, 11]
+        self.softmax_switch = False  #default is true, means "with softmax"
+
+
+##############################################################################
+#NotWithSoftmax_HardLabel_2D_Ignore end
+##############################################################################
 
 
 class TestSoftmaxWithCrossEntropyOpNoCudnn(TestSoftmaxWithCrossEntropyOp):
@@ -110,6 +324,7 @@ class TestSoftmaxWithCrossEntropyOpNoCudnn(TestSoftmaxWithCrossEntropyOp):
         self.axis = -1
         self.ignore_index = -1
         self.dtype = np.float32 if core.is_compiled_with_rocm() else np.float64
+        self.softmax_switch = True
 
 
 @unittest.skipIf(not core.is_compiled_with_cuda(),
@@ -188,6 +403,7 @@ class TestSoftmaxWithCrossEntropyOp2(TestSoftmaxWithCrossEntropyOp):
         self.axis = -1
         self.ignore_index = -1
         self.shape = [41, 37]
+        self.softmax_switch = True
 
     def test_check_output(self):
         self.check_output()
@@ -213,6 +429,7 @@ class TestSoftmaxWithCrossEntropyOp3(TestSoftmaxWithCrossEntropyOp):
         self.ignore_index = 5
         self.axis = -1
         self.dtype = np.float32 if core.is_compiled_with_rocm() else np.float64
+        self.softmax_switch = True
 
 
 class TestSoftmaxWithCrossEntropyOp3NoCudnn(TestSoftmaxWithCrossEntropyOp3):
@@ -224,6 +441,7 @@ class TestSoftmaxWithCrossEntropyOp3NoCudnn(TestSoftmaxWithCrossEntropyOp3):
         self.ignore_index = 4
         self.axis = -1
         self.dtype = np.float32 if core.is_compiled_with_rocm() else np.float64
+        self.softmax_switch = True
 
 
 class TestSoftmaxWithCrossEntropyOpAxis1(TestSoftmaxWithCrossEntropyOp):
@@ -240,6 +458,7 @@ class TestSoftmaxWithCrossEntropyOpAxis1(TestSoftmaxWithCrossEntropyOp):
         self.axis = 0
         self.ignore_index = -1
         self.shape = [3, 5, 7, 11]
+        self.softmax_switch = True
 
 
 class TestSoftmaxWithCrossEntropyOpAxis2(TestSoftmaxWithCrossEntropyOp):
@@ -256,6 +475,7 @@ class TestSoftmaxWithCrossEntropyOpAxis2(TestSoftmaxWithCrossEntropyOp):
         self.axis = 1
         self.ignore_index = -1
         self.shape = [3, 5, 7, 11]
+        self.softmax_switch = True
 
 
 class TestSoftmaxWithCrossEntropyOpAxis3(TestSoftmaxWithCrossEntropyOp):
@@ -272,6 +492,7 @@ class TestSoftmaxWithCrossEntropyOpAxis3(TestSoftmaxWithCrossEntropyOp):
         self.axis = 2
         self.ignore_index = -1
         self.shape = [3, 5, 7, 11]
+        self.softmax_switch = True
 
 
 class TestSoftmaxWithCrossEntropyOpAxis4(TestSoftmaxWithCrossEntropyOp):
@@ -288,6 +509,7 @@ class TestSoftmaxWithCrossEntropyOpAxis4(TestSoftmaxWithCrossEntropyOp):
         self.axis = 3
         self.ignore_index = -1
         self.shape = [3, 5, 7, 11]
+        self.softmax_switch = True
 
 
 class TestSoftmaxWithCrossEntropyOpAxisDimEqualOne(
@@ -305,6 +527,7 @@ class TestSoftmaxWithCrossEntropyOpAxisDimEqualOne(
         self.axis = -1
         self.ignore_index = -1
         self.shape = [3, 5, 7, 1]
+        self.softmax_switch = True
 
 
 class TestSoftmaxWithCrossEntropyOpNoCudnnFp16Axis1(
@@ -317,6 +540,7 @@ class TestSoftmaxWithCrossEntropyOpNoCudnnFp16Axis1(
         self.axis = 0
         self.ignore_index = -1
         self.dtype = np.float16
+        self.softmax_switch = True
 
 
 class TestSoftmaxWithCrossEntropyOpNoCudnnFp16Axis2(
@@ -329,6 +553,7 @@ class TestSoftmaxWithCrossEntropyOpNoCudnnFp16Axis2(
         self.axis = 1
         self.ignore_index = -1
         self.dtype = np.float16
+        self.softmax_switch = True
 
 
 class TestSoftmaxWithCrossEntropyOpNoCudnnFp16Axis3(
@@ -341,6 +566,7 @@ class TestSoftmaxWithCrossEntropyOpNoCudnnFp16Axis3(
         self.axis = 2
         self.ignore_index = -1
         self.dtype = np.float16
+        self.softmax_switch = True
 
 
 class TestSoftmaxWithCrossEntropyOpSoftLabelAxis1(
@@ -353,6 +579,7 @@ class TestSoftmaxWithCrossEntropyOpSoftLabelAxis1(
         self.axis = 0
         self.ignore_index = -1
         self.dtype = np.float32 if core.is_compiled_with_rocm() else np.float64
+        self.softmax_switch = True
 
 
 class TestSoftmaxWithCrossEntropyOpSoftLabelAxis2(
@@ -365,6 +592,7 @@ class TestSoftmaxWithCrossEntropyOpSoftLabelAxis2(
         self.axis = 1
         self.ignore_index = -1
         self.dtype = np.float32 if core.is_compiled_with_rocm() else np.float64
+        self.softmax_switch = True
 
 
 class TestSoftmaxWithCrossEntropyOpSoftLabelAxis3(
@@ -377,6 +605,7 @@ class TestSoftmaxWithCrossEntropyOpSoftLabelAxis3(
         self.axis = 2
         self.ignore_index = -1
         self.dtype = np.float32 if core.is_compiled_with_rocm() else np.float64
+        self.softmax_switch = True
 
 
 class TestSoftmaxWithCrossEntropyOpSoftLabelAxis4(
@@ -389,6 +618,7 @@ class TestSoftmaxWithCrossEntropyOpSoftLabelAxis4(
         self.axis = 3
         self.ignore_index = -1
         self.dtype = np.float32 if core.is_compiled_with_rocm() else np.float64
+        self.softmax_switch = True
 
 
 class TestSoftmaxWithCrossEntropyOpIgnoreIndexNoCudnnAxis1(
@@ -401,6 +631,7 @@ class TestSoftmaxWithCrossEntropyOpIgnoreIndexNoCudnnAxis1(
         self.ignore_index = 1
         self.axis = 0
         self.dtype = np.float32 if core.is_compiled_with_rocm() else np.float64
+        self.softmax_switch = True
 
 
 class TestSoftmaxWithCrossEntropyOpIgnoreIndexNoCudnnAxis2(
@@ -413,6 +644,7 @@ class TestSoftmaxWithCrossEntropyOpIgnoreIndexNoCudnnAxis2(
         self.ignore_index = 0
         self.axis = 1
         self.dtype = np.float32 if core.is_compiled_with_rocm() else np.float64
+        self.softmax_switch = True
 
 
 class TestSoftmaxWithCrossEntropyOpIgnoreIndexNoCudnnAxis3(
@@ -425,6 +657,7 @@ class TestSoftmaxWithCrossEntropyOpIgnoreIndexNoCudnnAxis3(
         self.ignore_index = 3
         self.axis = 2
         self.dtype = np.float32 if core.is_compiled_with_rocm() else np.float64
+        self.softmax_switch = True
 
 
 class TestSoftmaxWithCrossEntropyOpIgnoreIndexNoCudnnAxis4(
@@ -437,6 +670,7 @@ class TestSoftmaxWithCrossEntropyOpIgnoreIndexNoCudnnAxis4(
         self.ignore_index = 3
         self.axis = 3
         self.dtype = np.float32 if core.is_compiled_with_rocm() else np.float64
+        self.softmax_switch = True
 
 
 class TestSoftmaxWithCrossEntropyOpBoundary0(TestSoftmaxWithCrossEntropyOp):
@@ -454,6 +688,7 @@ class TestSoftmaxWithCrossEntropyOpBoundary0(TestSoftmaxWithCrossEntropyOp):
         self.ignore_index = -1
         self.dtype = np.float32 if core.is_compiled_with_rocm() else np.float64
         self.logits = np.full(self.shape, -500.0).astype(self.dtype)
+        self.softmax_switch = True
 
 
 class TestSoftmaxWithCrossEntropyOpBoundary1(TestSoftmaxWithCrossEntropyOp):
@@ -472,6 +707,7 @@ class TestSoftmaxWithCrossEntropyOpBoundary1(TestSoftmaxWithCrossEntropyOp):
         self.dtype = np.float32 if core.is_compiled_with_rocm() else np.float64
         self.logits = np.full(self.shape, 1000.0).astype(self.dtype)
         self.logits[:, :, 0, :] = -1000.0
+        self.softmax_switch = True
 
 
 if __name__ == "__main__":