# 🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨 # This file was automatically generated from src/transformers/models/hrm_text/modular_hrm_text.py. # Do NOT edit this file manually as any edits will be overwritten by the generation of # the file from the modular. If any change should be done, please apply the change to the # modular_hrm_text.py file directly. One of our CI enforces this. # 🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨🚨 # Copyright 2026 The Sapient AI Authors and the HuggingFace Inc. team. 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. from collections.abc import Callable from contextlib import nullcontext from typing import Optional import torch from torch import nn from transformers import initialization as init from transformers.activations import ACT2FN from transformers.cache_utils import Cache, DynamicCache from transformers.configuration_utils import PreTrainedConfig from transformers.generation import GenerationMixin from transformers.integrations import use_kernel_func_from_hub, use_kernelized_func from transformers.masking_utils import create_causal_mask, create_masks_for_generate from transformers.modeling_layers import GradientCheckpointingLayer from transformers.modeling_outputs import BaseModelOutputWithPast, CausalLMOutputWithPast from transformers.modeling_rope_utils import ROPE_INIT_FUNCTIONS, dynamic_rope_update from transformers.modeling_utils import ALL_ATTENTION_FUNCTIONS, PreTrainedModel from transformers.processing_utils import Unpack from transformers.utils import auto_docstring, can_return_tuple, logging from transformers.utils.generic import ( TransformersKwargs, is_flash_attention_requested, maybe_autocast, merge_with_config_defaults, split_attention_implementation, ) from transformers.utils.output_capturing import capture_outputs from .configuration_hrm_text import HrmTextConfig logger = logging.get_logger(__name__) class HrmTextRMSNorm(torch.nn.Module): def __init__(self, eps: float = 1e-6): super().__init__() self.eps = eps def _norm(self, x): return x * torch.rsqrt(x.pow(2).mean(-1, keepdim=True) + self.eps) def forward(self, x): return self._norm(x.float()).type_as(x) def extra_repr(self): return f"eps={self.eps}" class HrmTextMLP(nn.Module): def __init__(self, config): super().__init__() self.config = config self.hidden_size = config.hidden_size self.intermediate_size = config.intermediate_size self.gate_proj = nn.Linear(self.hidden_size, self.intermediate_size, bias=config.mlp_bias) self.up_proj = nn.Linear(self.hidden_size, self.intermediate_size, bias=config.mlp_bias) self.down_proj = nn.Linear(self.intermediate_size, self.hidden_size, bias=config.mlp_bias) self.act_fn = ACT2FN[config.hidden_act] def forward(self, x): down_proj = self.down_proj(self.act_fn(self.gate_proj(x)) * self.up_proj(x)) return down_proj def rotate_half(x): """Rotates half the hidden dims of the input.""" x1 = x[..., : x.shape[-1] // 2] x2 = x[..., x.shape[-1] // 2 :] return torch.cat((-x2, x1), dim=-1) @use_kernel_func_from_hub("rotary_pos_emb") def apply_rotary_pos_emb(q, k, cos, sin, unsqueeze_dim=1): """Applies Rotary Position Embedding to the query and key tensors. Args: q (`torch.Tensor`): The query tensor. k (`torch.Tensor`): The key tensor. cos (`torch.Tensor`): The cosine part of the rotary embedding. sin (`torch.Tensor`): The sine part of the rotary embedding. unsqueeze_dim (`int`, *optional*, defaults to 1): The 'unsqueeze_dim' argument specifies the dimension along which to unsqueeze cos[position_ids] and sin[position_ids] so that they can be properly broadcasted to the dimensions of q and k. For example, note that cos[position_ids] and sin[position_ids] have the shape [batch_size, seq_len, head_dim]. Then, if q and k have the shape [batch_size, heads, seq_len, head_dim], then setting unsqueeze_dim=1 makes cos[position_ids] and sin[position_ids] broadcastable to the shapes of q and k. Similarly, if q and k have the shape [batch_size, seq_len, heads, head_dim], then set unsqueeze_dim=2. Returns: `tuple(torch.Tensor)` comprising of the query and key tensors rotated using the Rotary Position Embedding. """ cos = cos.unsqueeze(unsqueeze_dim) sin = sin.unsqueeze(unsqueeze_dim) q_embed = (q * cos) + (rotate_half(q) * sin) k_embed = (k * cos) + (rotate_half(k) * sin) return q_embed, k_embed def repeat_kv(hidden_states: torch.Tensor, n_rep: int) -> torch.Tensor: """ This is the equivalent of torch.repeat_interleave(x, dim=1, repeats=n_rep). The hidden states go from (batch, num_key_value_heads, seqlen, head_dim) to (batch, num_attention_heads, seqlen, head_dim) """ batch, num_key_value_heads, slen, head_dim = hidden_states.shape if n_rep == 1: return hidden_states hidden_states = hidden_states[:, :, None, :, :].expand(batch, num_key_value_heads, n_rep, slen, head_dim) return hidden_states.reshape(batch, num_key_value_heads * n_rep, slen, head_dim) def eager_attention_forward( module: nn.Module, query: torch.Tensor, key: torch.Tensor, value: torch.Tensor, attention_mask: torch.Tensor | None, scaling: float, dropout: float = 0.0, **kwargs: Unpack[TransformersKwargs], ): key_states = repeat_kv(key, module.num_key_value_groups) value_states = repeat_kv(value, module.num_key_value_groups) attn_weights = torch.matmul(query, key_states.transpose(2, 3)) * scaling if attention_mask is not None: attn_weights = attn_weights + attention_mask attn_weights = nn.functional.softmax(attn_weights, dim=-1, dtype=torch.float32).to(query.dtype) attn_weights = nn.functional.dropout(attn_weights, p=dropout, training=module.training) attn_output = torch.matmul(attn_weights, value_states) attn_output = attn_output.transpose(1, 2).contiguous() return attn_output, attn_weights @use_kernelized_func(apply_rotary_pos_emb) class HrmTextAttention(nn.Module): """Multi-headed attention from 'Attention Is All You Need' paper""" def __init__(self, config: HrmTextConfig, layer_idx: int): super().__init__() self.config = config self.layer_idx = layer_idx self.head_dim = getattr(config, "head_dim", config.hidden_size // config.num_attention_heads) self.num_key_value_groups = 1 # Uses MHA instead of GQA self.scaling = self.head_dim**-0.5 self.attention_dropout = config.attention_dropout self.is_causal = True self.q_proj = nn.Linear( config.hidden_size, config.num_attention_heads * self.head_dim, bias=config.attention_bias ) self.k_proj = nn.Linear( config.hidden_size, config.num_attention_heads * self.head_dim, bias=config.attention_bias, ) self.v_proj = nn.Linear( config.hidden_size, config.num_attention_heads * self.head_dim, bias=config.attention_bias, ) self.o_proj = nn.Linear( config.num_attention_heads * self.head_dim, config.hidden_size, bias=config.attention_bias ) # Additional sigmoid gate applied at the end self.gate_proj = nn.Linear( config.hidden_size, config.num_attention_heads * self.head_dim, bias=config.attention_bias, ) def forward( self, hidden_states: torch.Tensor, position_embeddings: tuple[torch.Tensor, torch.Tensor] | None = None, attention_mask: torch.Tensor | None = None, past_key_values: Cache | None = None, cycle_offset: int = 0, **kwargs: Unpack[TransformersKwargs], ) -> tuple[torch.Tensor, torch.Tensor]: input_shape = hidden_states.shape[:-1] hidden_shape = (*input_shape, -1, self.head_dim) query_states = self.q_proj(hidden_states).view(hidden_shape).transpose(1, 2) key_states = self.k_proj(hidden_states).view(hidden_shape).transpose(1, 2) value_states = self.v_proj(hidden_states).view(hidden_shape).transpose(1, 2) gate_states = self.gate_proj(hidden_states).view(hidden_shape) cos, sin = position_embeddings query_states, key_states = apply_rotary_pos_emb(query_states, key_states, cos, sin) if past_key_values is not None: # Adjust cache slot by `cycle_offset` which is determined by it's current recurrent step through the stacks key_states, value_states = past_key_values.update(key_states, value_states, self.layer_idx + cycle_offset) attention_interface: Callable = ALL_ATTENTION_FUNCTIONS.get_interface( self.config._attn_implementation, eager_attention_forward ) attn_output, attn_weights = attention_interface( self, query_states, key_states, value_states, attention_mask, dropout=0.0 if not self.training else self.attention_dropout, scaling=self.scaling, **kwargs, ) # Additional sigmoid gating (similar to Qwen3Next) attn_output = torch.sigmoid(gate_states) * attn_output attn_output = attn_output.reshape(*input_shape, -1).contiguous() attn_output = self.o_proj(attn_output) return attn_output, attn_weights class HrmTextDecoderLayer(GradientCheckpointingLayer): def __init__(self, config: HrmTextConfig, layer_idx: int): super().__init__() self.hidden_size = config.hidden_size self.self_attn = HrmTextAttention(config=config, layer_idx=layer_idx) self.mlp = HrmTextMLP(config) self.input_layernorm = HrmTextRMSNorm(eps=config.rms_norm_eps) self.post_attention_layernorm = HrmTextRMSNorm(eps=config.rms_norm_eps) def forward( self, hidden_states: torch.Tensor, attention_mask: torch.Tensor | None = None, position_ids: torch.LongTensor | None = None, past_key_values: Cache | None = None, use_cache: bool | None = False, position_embeddings: tuple[torch.Tensor, torch.Tensor] | None = None, **kwargs: Unpack[TransformersKwargs], ) -> torch.Tensor: residual = hidden_states hidden_states = self.input_layernorm(hidden_states) # Self Attention hidden_states, _ = self.self_attn( hidden_states=hidden_states, attention_mask=attention_mask, position_ids=position_ids, past_key_values=past_key_values, use_cache=use_cache, position_embeddings=position_embeddings, **kwargs, ) hidden_states = residual + hidden_states # Fully Connected residual = hidden_states hidden_states = self.post_attention_layernorm(hidden_states) hidden_states = self.mlp(hidden_states) hidden_states = residual + hidden_states return hidden_states class HrmTextStack(nn.Module): """A single transformer stack — used twice inside, once as H module and once as L module""" def __init__(self, config: HrmTextConfig): super().__init__() self.layers = nn.ModuleList( [HrmTextDecoderLayer(config, layer_idx) for layer_idx in range(config.num_layers_per_stack)] ) self.final_norm = HrmTextRMSNorm(eps=config.rms_norm_eps) def forward( self, hidden_states: torch.Tensor, attention_mask: torch.Tensor | None = None, past_key_values: Cache | None = None, position_embeddings: tuple[torch.Tensor, torch.Tensor] | None = None, cycle_offset: int = 0, **kwargs: Unpack[TransformersKwargs], ) -> torch.Tensor: for layer in self.layers: hidden_states = layer( hidden_states, attention_mask=attention_mask, past_key_values=past_key_values, position_embeddings=position_embeddings, cycle_offset=cycle_offset, **kwargs, ) return self.final_norm(hidden_states) @auto_docstring class HrmTextPreTrainedModel(PreTrainedModel): config: HrmTextConfig base_model_prefix = "model" supports_gradient_checkpointing = True _no_split_modules = ["HrmTextDecoderLayer"] _skip_keys_device_placement = ["past_key_values"] _supports_flash_attn = True _supports_sdpa = True _supports_flex_attn = True _can_compile_fullgraph = True _supports_attention_backend = True _can_record_outputs = { "hidden_states": HrmTextDecoderLayer, "attentions": HrmTextAttention, } def _check_and_adjust_attn_implementation( self, attn_implementation: str | None, is_init_check: bool = False, allow_all_kernels: bool = False ) -> str: if attn_implementation is not None and self.config.prefix_lm: _, base_implementation = split_attention_implementation(attn_implementation) if is_flash_attention_requested(requested_attention_implementation=base_implementation): raise ValueError( f"`attn_implementation={attn_implementation!r}` is not supported when " "`config.prefix_lm=True`: FlashAttention cannot represent the PrefixLM 4-D mask " "overlay. Use `'sdpa'` (default) or `'flex_attention'`, or set `config.prefix_lm=False`." ) return super()._check_and_adjust_attn_implementation(attn_implementation, is_init_check, allow_all_kernels) @torch.no_grad() def _init_weights(self, module): super()._init_weights(module) if isinstance(module, HrmTextModel): init.zeros_(module.z_L_init) # `z_L_init` is the frozen low-cycle initial state and never trains. module.z_L_init.requires_grad_(False) # trf-ignore: TRF012 class HrmTextRotaryEmbedding(nn.Module): inv_freq: torch.Tensor # fix linting for `register_buffer` def __init__(self, config: HrmTextConfig, device=None): super().__init__() self.max_seq_len_cached = config.max_position_embeddings self.original_max_seq_len = config.max_position_embeddings self.config = config self.rope_type = self.config.rope_parameters["rope_type"] rope_init_fn: Callable = self.compute_default_rope_parameters if self.rope_type != "default": rope_init_fn = ROPE_INIT_FUNCTIONS[self.rope_type] inv_freq, self.attention_scaling = rope_init_fn(self.config, device) self.register_buffer("inv_freq", inv_freq, persistent=False) self.register_buffer("original_inv_freq", inv_freq.clone(), persistent=False) @staticmethod def compute_default_rope_parameters( config: HrmTextConfig | None = None, device: Optional["torch.device"] = None, seq_len: int | None = None, ) -> tuple["torch.Tensor", float]: """ Computes the inverse frequencies according to the original RoPE implementation Args: config ([`~transformers.PreTrainedConfig`]): The model configuration. device (`torch.device`): The device to use for initialization of the inverse frequencies. seq_len (`int`, *optional*): The current sequence length. Unused for this type of RoPE. Returns: Tuple of (`torch.Tensor`, `float`), containing the inverse frequencies for the RoPE embeddings and the post-processing scaling factor applied to the computed cos/sin (unused in this type of RoPE). """ base = config.rope_parameters["rope_theta"] dim = getattr(config, "head_dim", None) or config.hidden_size // config.num_attention_heads attention_factor = 1.0 # Unused in this type of RoPE # Compute the inverse frequencies inv_freq = 1.0 / ( base ** (torch.arange(0, dim, 2, dtype=torch.int64).to(device=device, dtype=torch.float) / dim) ) return inv_freq, attention_factor @torch.no_grad() @dynamic_rope_update # power user: used with advanced RoPE types (e.g. dynamic rope) def forward(self, x, position_ids): inv_freq_expanded = self.inv_freq[None, :, None].float().expand(position_ids.shape[0], -1, 1).to(x.device) position_ids_expanded = position_ids[:, None, :].float() device_type = x.device.type if isinstance(x.device.type, str) and x.device.type != "mps" else "cpu" with maybe_autocast(device_type=device_type, enabled=False): # Force float32 freqs = (inv_freq_expanded.float() @ position_ids_expanded.float()).transpose(1, 2) emb = torch.cat((freqs, freqs), dim=-1) cos = emb.cos() * self.attention_scaling sin = emb.sin() * self.attention_scaling return cos.to(dtype=x.dtype), sin.to(dtype=x.dtype) @auto_docstring class HrmTextModel(HrmTextPreTrainedModel): def __init__(self, config: HrmTextConfig): super().__init__(config) self.padding_idx = config.pad_token_id self.vocab_size = config.vocab_size self.embed_tokens = nn.Embedding(config.vocab_size, config.hidden_size, self.padding_idx) self.rotary_emb = HrmTextRotaryEmbedding(config=config) self.gradient_checkpointing = False self.embedding_scale = config.embedding_scale # Recursive module structures self.L_module = HrmTextStack(config) self.H_module = HrmTextStack(config) # Initial state for the low cycle module self.z_L_init = nn.Parameter(torch.zeros(config.hidden_size), requires_grad=False) raw_bp = list(config.L_bp_cycles) self.L_bp_cycles_padded = [1] * max(0, config.H_cycles - len(raw_bp)) + raw_bp # Initialize weights and apply final processing self.post_init() @merge_with_config_defaults @capture_outputs @auto_docstring def forward( self, input_ids: torch.LongTensor | None = None, attention_mask: torch.Tensor | None = None, position_ids: torch.LongTensor | None = None, past_key_values: Cache | None = None, token_type_ids: torch.LongTensor | None = None, inputs_embeds: torch.FloatTensor | None = None, use_cache: bool | None = None, **kwargs: Unpack[TransformersKwargs], ) -> BaseModelOutputWithPast: r""" token_type_ids (`torch.LongTensor` of shape `(batch, seq_len)`, *optional*): Per-position bidirectional/causal indicator. Tokens with `token_type_ids == 1` form a single bidirectional block; all other positions are causal. """ if (input_ids is None) ^ (inputs_embeds is not None): raise ValueError("You must specify exactly one of input_ids or inputs_embeds") if inputs_embeds is None: inputs_embeds = self.embed_tokens(input_ids) # Additional scaling on the input embeds inputs_embeds = inputs_embeds * self.embedding_scale if use_cache and past_key_values is None: past_key_values = DynamicCache(config=self.config) if position_ids is None: past_seen_tokens = past_key_values.get_seq_length() if past_key_values is not None else 0 position_ids = torch.arange(inputs_embeds.shape[1], device=inputs_embeds.device) + past_seen_tokens position_ids = position_ids.unsqueeze(0) # Create mask with optional prefix-based bidirectionality mask_kwargs = { "config": self.config, "inputs_embeds": inputs_embeds, "attention_mask": attention_mask, "past_key_values": past_key_values, "position_ids": position_ids, } is_first_iteration = past_key_values is None or not past_key_values.is_initialized if token_type_ids is not None and is_first_iteration: if self.config.prefix_lm: mask_kwargs["block_sequence_ids"] = torch.where(token_type_ids == 1, 0, -1) else: logger.warning_once("`token_type_ids` was provided but `config.prefix_lm=False`; ignoring it.") attention_mask = create_causal_mask(**mask_kwargs) position_embeddings = self.rotary_emb(inputs_embeds, position_ids) # Hierarchical (H/L)-cycle recurrence # # `z_H` - slow / high-level state hidden_states_high_cycle = inputs_embeds # `z_L` - fast / low-level state hidden_states_low_cycle = ( self.z_L_init.to(dtype=hidden_states_high_cycle.dtype, device=hidden_states_high_cycle.device) .expand_as(hidden_states_high_cycle) .contiguous() ) # Cache-slot layout under the recurrent forward: # # slot(h, l, layer) = (h * (L_cycles + 1) + l) * num_layers_per_stack + layer # ^— L-stack invocation at (h, l) # slot(h, H, layer) = (h * (L_cycles + 1) + L_cycles) * num_layers_per_stack + layer # ^— trailing H-stack invocation # # That totals `num_layers_per_stack * H_cycles * (L_cycles + 1)` slots, i.e. the `config.num_hidden_layers`. num_layers_per_stack = self.config.num_layers_per_stack for high_cycle_idx in range(self.config.H_cycles): # `L_bp_cycles` k-step grad trick: only the trailing `num_grad_iterations` of the # `L_cycles` inner iterations propagate gradients; earlier iterations run under # `torch.no_grad()` to bound activation memory. num_grad_iterations = ( self.L_bp_cycles_padded[high_cycle_idx] if high_cycle_idx < len(self.L_bp_cycles_padded) else 1 ) grad_threshold = self.config.L_cycles - num_grad_iterations for low_cycle_idx in range(self.config.L_cycles): cycle_offset = (high_cycle_idx * (self.config.L_cycles + 1) + low_cycle_idx) * num_layers_per_stack ctx = nullcontext() if low_cycle_idx >= grad_threshold else torch.no_grad() with ctx: hidden_states_low_cycle = self.L_module( hidden_states_low_cycle.to(hidden_states_high_cycle.device) + hidden_states_high_cycle, attention_mask=attention_mask, past_key_values=past_key_values, position_embeddings=position_embeddings, position_ids=position_ids, cycle_offset=cycle_offset, **kwargs, ) cycle_offset = (high_cycle_idx * (self.config.L_cycles + 1) + self.config.L_cycles) * num_layers_per_stack hidden_states_high_cycle = self.H_module( hidden_states_high_cycle + hidden_states_low_cycle.to(hidden_states_high_cycle.device), attention_mask=attention_mask, past_key_values=past_key_values, position_embeddings=position_embeddings, position_ids=position_ids, cycle_offset=cycle_offset, **kwargs, ) return BaseModelOutputWithPast( last_hidden_state=hidden_states_high_cycle, past_key_values=past_key_values, ) @auto_docstring class HrmTextForCausalLM(HrmTextPreTrainedModel, GenerationMixin): _tied_weights_keys = {"lm_head.weight": "model.embed_tokens.weight"} _tp_plan = {"lm_head": "colwise_gather_output"} _pp_plan = {"lm_head": (["hidden_states"], ["logits"])} def __init__(self, config): super().__init__(config) self.model = HrmTextModel(config) self.vocab_size = config.vocab_size self.lm_head = nn.Linear(config.hidden_size, config.vocab_size, bias=False) # Initialize weights and apply final processing self.post_init() @can_return_tuple @auto_docstring def forward( self, input_ids: torch.LongTensor | None = None, attention_mask: torch.Tensor | None = None, position_ids: torch.LongTensor | None = None, past_key_values: Cache | None = None, token_type_ids: torch.LongTensor | None = None, inputs_embeds: torch.FloatTensor | None = None, labels: torch.LongTensor | None = None, use_cache: bool | None = None, logits_to_keep: int | torch.Tensor = 0, **kwargs: Unpack[TransformersKwargs], ) -> CausalLMOutputWithPast: r""" token_type_ids (`torch.LongTensor` of shape `(batch, seq_len)`, *optional*): Per-position bidirectional/causal indicator. Tokens with `token_type_ids == 1` form a single bidirectional block; all other positions are causal. """ outputs: BaseModelOutputWithPast = self.model( input_ids=input_ids, attention_mask=attention_mask, position_ids=position_ids, past_key_values=past_key_values, token_type_ids=token_type_ids, inputs_embeds=inputs_embeds, use_cache=use_cache, **kwargs, ) hidden_states = outputs.last_hidden_state slice_indices = slice(-logits_to_keep, None) if isinstance(logits_to_keep, int) else logits_to_keep logits = self.lm_head(hidden_states[:, slice_indices, :]) loss = None if labels is not None: loss = self.loss_function(logits=logits, labels=labels, vocab_size=self.config.vocab_size, **kwargs) return CausalLMOutputWithPast( loss=loss, logits=logits, past_key_values=outputs.past_key_values, hidden_states=outputs.hidden_states, attentions=outputs.attentions, ) @staticmethod def create_masks_for_generate( config: PreTrainedConfig, inputs_embeds: torch.Tensor, attention_mask: torch.Tensor | None, past_key_values: Cache | None, position_ids: torch.Tensor | None, token_type_ids: torch.Tensor | None = None, is_first_iteration: bool | None = False, **kwargs, ) -> dict: mask_kwargs = { "config": config, "inputs_embeds": inputs_embeds, "attention_mask": attention_mask, "past_key_values": past_key_values, "position_ids": position_ids, } if token_type_ids is not None and is_first_iteration: if config.prefix_lm: mask_kwargs["block_sequence_ids"] = torch.where(token_type_ids == 1, 0, -1) else: logger.warning_once("`token_type_ids` was provided but `config.prefix_lm=False`; ignoring it.") return create_masks_for_generate(**mask_kwargs) __all__ = ["HrmTextForCausalLM", "HrmTextModel", "HrmTextPreTrainedModel"]