Back out "bucket_permute kernel to accelerate bucktize in rebatching" (#5079)

Summary:

X-link: facebookresearch/FBGEMM#2085

backout bucket_permute kernel due to NE mismatch in serving eval test

Reviewed By: ghq24int

Differential Revision: D86110675

Author: royren622

fbgemm_gpu/src/sparse_ops/sparse_block_bucketize_features.cu

@@ -402,68 +402,6 @@ __launch_bounds__(kMaxThreads) void _populate_bucketized_permute_cuda_kernel(
   }
 }
 
-template <typename offset_t, typename index_t>
-__global__
-__launch_bounds__(kMaxThreads) void _populate_bucketized_permute_cuda_kernel_vec(
-    const offset_t* const length_data,
-    const offset_t* const offset_data,
-    offset_t* const bucketized_offsets_data,
-    const index_t* const bucket_mapping_data,
-    index_t* const bucketized_permute_data_out,
-    int32_t lengths_size) {
-  uint32_t threads_per_group = 1;
-  if (sizeof(offset_t) == 8 && sizeof(index_t) == 8) {
-    threads_per_group = 4;
-  }
-  uint32_t tid = blockIdx.x * blockDim.x + threadIdx.x;
-  uint32_t idx_within_group = tid % threads_per_group; // tid & 0x3;
-  uint32_t group_idx = tid / threads_per_group; // tid & 0xfffffffc;
-  for (uint32_t b_t = group_idx; b_t < lengths_size;
-       b_t += (gridDim.x * blockDim.x / threads_per_group)) {
-    const auto length = length_data[b_t];
-    const auto offset = offset_data[b_t];
-
-    // Check if we should use 8-byte atomic operations for this data type
-    // combination
-    if (sizeof(offset_t) == 8 && sizeof(index_t) == 8) {
-      // Check alignment once per b_t outside the inner loop
-      offset_t* const base_offset_ptr = &bucketized_offsets_data[b_t];
-      bool is_aligned = (reinterpret_cast<uintptr_t>(base_offset_ptr) %
-                         alignof(unsigned long long int)) == 0;
-      if (is_aligned) {
-        for (uint32_t i = idx_within_group; i < length;
-             i += threads_per_group) {
-          const auto index = offset + i;
-          const auto bucket = bucket_mapping_data[index];
-          unsigned long long int* const p =
-              reinterpret_cast<unsigned long long int*>(
-                  &bucketized_offsets_data[bucket * lengths_size + b_t]);
-          bucketized_permute_data_out[index] = atomicAdd(p, 1llu);
-        }
-      } else {
-        // Fall back to non-atomic increment if misaligned
-        for (uint32_t i = idx_within_group; i < length;
-             i += threads_per_group) {
-          const auto index = offset + i;
-          const auto bucket = bucket_mapping_data[index];
-          offset_t* const offset_ptr =
-              &bucketized_offsets_data[bucket * lengths_size + b_t];
-          bucketized_permute_data_out[index] = offset_ptr[0];
-          offset_ptr[0]++;
-        }
-      }
-    } else {
-      // 4-byte operations - no alignment check needed
-      for (uint32_t i = idx_within_group; i < length; i += threads_per_group) {
-        const auto index = offset + i;
-        const auto bucket = bucket_mapping_data[index];
-        bucketized_permute_data_out[index] =
-            bucketized_offsets_data[bucket * lengths_size + b_t]++;
-      }
-    }
-  }
-}
-
 #define LAUNCH_BLOCK_BUCKETIZE_SEQUENCE_SPARSE_FEATURES_CUDA_KERNEL_WITH_WEIGHT( \
     bucketize_pos, return_bucket_mapping)                                        \
   AT_DISPATCH_INDEX_TYPES(                                                       \
@@ -1104,9 +1042,7 @@ DLL_PUBLIC Tensor populate_bucketized_permute_cuda(
             "_populate_bucketized_permute_cuda_kernel2",
             [&] {
               FBGEMM_LAUNCH_KERNEL(
-                  (_populate_bucketized_permute_cuda_kernel_vec<
-                      offset_t,
-                      index_t>),
+                  (_populate_bucketized_permute_cuda_kernel<offset_t, index_t>),
                   num_blocks,
                   threads_per_block,
                   0,