[Gen, FT] Use tlength instead of params.timestep for rotary

csrc/ft_attention/decoder_masked_multihead_attention_template.hpp

@@ -1082,10 +1082,10 @@ __global__ void masked_multihead_attention_kernel(Multihead_attention_params<T,
     const int padd_len = (params.total_padding_tokens == nullptr) ? 0 : params.total_padding_tokens[bi];
     if (params.rotary_embedding_dim > 0 && !params.neox_rotary_style) {
         if (handle_kv) {
-            apply_rotary_embedding(q, k, tidx, params.rotary_embedding_dim, params.timestep - padd_len);
+            apply_rotary_embedding(q, k, tidx, params.rotary_embedding_dim, tlength - padd_len);
         }
         else {
-            apply_rotary_embedding(q, tidx, params.rotary_embedding_dim, params.timestep - padd_len);
+            apply_rotary_embedding(q, tidx, params.rotary_embedding_dim, tlength - padd_len);
         }
     }
     else if (params.rotary_embedding_dim > 0 && params.neox_rotary_style) {
@@ -1120,13 +1120,13 @@ __global__ void masked_multihead_attention_kernel(Multihead_attention_params<T,
                 mmha::vec_from_smem_transpose(k, k_smem, transpose_idx, smem_pitch);
 
                 mmha::apply_rotary_embedding(
-                    q, k, transpose_idx / tidx_factor, params.rotary_embedding_dim, params.timestep - padd_len);
+                    q, k, transpose_idx / tidx_factor, params.rotary_embedding_dim, tlength - padd_len);
 
                 mmha::write_smem_transpose(k, k_smem, transpose_idx, smem_pitch);
             }
             else {
                 mmha::apply_rotary_embedding(
-                    q, transpose_idx / tidx_factor, params.rotary_embedding_dim, params.timestep);
+                    q, transpose_idx / tidx_factor, params.rotary_embedding_dim, tlength);
             }
             mmha::write_smem_transpose(q, q_smem, transpose_idx, smem_pitch);
         }