Fix einsum accuracy diff when with contraction dim (#74303)

* fix einsum accuracy diff when with contraction dim

* refine

Author: ggggxm

paddle/phi/kernels/impl/einsum_grad_kernel_impl.h

@@ -43,17 +43,35 @@ DenseTensor PerformTileAndReduction(const Context& dev_ctx,
   std::vector<int64_t> repeat_times;
   std::vector<int64_t> resize_dims;
   std::vector<int64_t> recover_shape;
-  for (int c : op_label) {
+  std::vector<int64_t> t_shape = common::vectorize<int64_t>(t.dims());
+  for (int i = 0; i < op_label.size(); i++) {
+    int c = op_label[i];
     if (label2type[c] == LabelType::Reduction) {
       repeat_times.push_back(label2shape[c]);
       resize_dims.push_back(1);
       recover_shape.push_back(label2shape[c]);
+      t_shape.insert(t_shape.begin() + i, 1);
     } else {
       resize_dims.push_back(label2shape[c]);
       repeat_times.push_back(1);
       recover_shape.push_back(label2shape[c]);
     }
   }
+  PADDLE_ENFORCE_EQ(op_label.size(),
+                    t_shape.size(),
+                    common::errors::InvalidArgument(
+                        "Input shape size doesn't match label nums, input "
+                        "shape size: `%d`, but got label nums: `%d`",
+                        t_shape.size(),
+                        op_label.size()));
+  for (int i = 0; i < op_label.size(); i++) {
+    int c = op_label[i];
+    if (label2type[c] == LabelType::Contraction &&
+        t_shape[i] != label2shape[c]) {
+      repeat_times[i] = label2shape[c];
+      resize_dims[i] = 1;
+    }
+  }
   t.Resize(common::make_ddim(resize_dims));
   DenseTensor after_tile;
   if (std::all_of(repeat_times.begin(), repeat_times.end(), [](int64_t x) {

paddle/phi/kernels/impl/einsum_kernel_impl.h

@@ -546,10 +546,51 @@ DenseTensor PerformContraction(
       trans_t = PerformTranspose<T, Context>(
           dev_ctx, reduct_t, perm, reordered_all_labels, label2type);
       if (cache[operand_idx] != nullptr) {
-        cache[operand_idx]->ShareBufferWith(trans_t);
-        cache[operand_idx]->Resize(trans_t.dims());
-        VLOG(5) << "Set dims of cache[" << operand_idx
-                << "]: " << trans_t.dims();
+        std::vector<int64_t> broadcast_shapes_restore(
+            broadcast_shapes[operand_idx].size());
+
+        auto contraction_dim1 =
+            [&](const std::vector<int64_t>& broadcast_shapes,
+                const std::vector<int64_t>& original_shapes) -> bool {
+          bool found = false;
+          for (size_t i = 0; i < broadcast_shapes.size(); ++i) {
+            if (broadcast_shapes[i] != original_shapes[i] &&
+                label2type[input_strs[operand_idx][i]] ==
+                    LabelType::Contraction) {
+              broadcast_shapes_restore[i] = original_shapes[i];
+              found = true;
+            } else {
+              broadcast_shapes_restore[i] = broadcast_shapes[i];
+            }
+          }
+          return found;
+        };
+        if (!contraction_dim1(broadcast_shapes[operand_idx],
+                              common::vectorize<int64_t>(t.dims()))) {
+          cache[operand_idx]->ShareBufferWith(trans_t);
+          cache[operand_idx]->Resize(trans_t.dims());
+          VLOG(5) << "Set dims of cache[" << operand_idx
+                  << "]: " << trans_t.dims();
+        } else {
+          auto reduct_t_for_cache =
+              PerformDiagonalAndReduction<T, Context>(dev_ctx,
+                                                      t,
+                                                      input_strs[operand_idx],
+                                                      perm,
+                                                      all_labels,
+                                                      broadcast_shapes_restore,
+                                                      label2type);
+          DenseTensor trans_t_for_cache;
+          trans_t_for_cache = PerformTranspose<T, Context>(dev_ctx,
+                                                           reduct_t_for_cache,
+                                                           perm,
+                                                           reordered_all_labels,
+                                                           label2type);
+          cache[operand_idx]->ShareBufferWith(trans_t_for_cache);
+          cache[operand_idx]->Resize(trans_t_for_cache.dims());
+          VLOG(5) << "Set dims of cache[" << operand_idx
+                  << "]: " << trans_t_for_cache.dims();
+        }
       }
     }
     auto mul_dims = GetShapeByType<int64_t>(