| 1 | # SPDX-License-Identifier: Apache-2.0 |
| 2 | # SPDX-FileCopyrightText: Copyright contributors to the vLLM project |
| 3 | """Fused compressor + FP8/MXFP4 UE8M0 quantization + KV cache insert kernels. |
| 4 | |
| 5 | Three specialized kernels: |
| 6 | - _fused_kv_compress_norm_rope_insert_sparse_attn: |
| 7 | head=512, nope=448 FP8 + rope=64 bf16 |
| 8 | - _fused_kv_compress_norm_rope_insert_indexer_attn: |
| 9 | head=128, all FP8, 1 block/token |
| 10 | - _fused_kv_compress_norm_rope_insert_indexer_mxfp4_attn: |
| 11 | head=128, MXFP4 (block=32), 4 ue8m0 bytes |
| 12 | |
| 13 | RoPE is register-based via tl.reshape -> tl.split -> tl.interleave (or the |
| 14 | even/odd halves are consumed directly for MXFP4, no interleave needed). |
| 15 | FP8 UE8M0 quant uses tl.reshape to tile [N_QUANT_BLOCKS, QUANT_BLOCK] for |
| 16 | per-block absmax entirely in registers. MXFP4 does the same tiling on the |
| 17 | even/odd halves, producing (N_QUANT_BLOCKS, MXFP4_BLOCK/2) packed nibbles |
| 18 | and N_QUANT_BLOCKS ue8m0 bytes. |
| 19 | """ |
| 20 | |
| 21 | from dataclasses import dataclass |
| 22 | from functools import lru_cache |
| 23 | from types import SimpleNamespace |
| 24 | from typing import Any |
| 25 | |
| 26 | import torch |
| 27 | |
| 28 | from vllm.model_executor.warmup.jit_warmup import kernel_launcher |
| 29 | from vllm.model_executor.warmup.jit_warmup_triton_helper import ( |
| 30 | LaunchSpec, |
| 31 | TritonWarmupTensor, |
| 32 | VllmTritonJitKernel, |
| 33 | ) |
| 34 | from vllm.platforms import current_platform |
| 35 | from vllm.triton_utils import tl, triton |
| 36 | from vllm.utils.math_utils import round_up |
| 37 | |
| 38 | if current_platform.is_rocm(): |
| 39 | from vllm.platforms.rocm import _ON_GFX950 |
| 40 | else: |
| 41 | _ON_GFX950 = False |
| 42 | |
| 43 | from .fused_indexer_q import _fp32x2_to_fp4x2 |
| 44 | |
| 45 | |
| 46 | def compress_norm_rope_store_triton( |
| 47 | state_cache: torch.Tensor, |
| 48 | num_actual: int, |
| 49 | token_to_req_indices: torch.Tensor, |
| 50 | positions: torch.Tensor, |
| 51 | slot_mapping: torch.Tensor, |
| 52 | block_table: torch.Tensor, |
| 53 | block_size: int, |
| 54 | state_width: int, |
| 55 | cos_sin_cache: torch.Tensor, |
| 56 | kv_cache: torch.Tensor, |
| 57 | k_cache_metadata: Any, |
| 58 | pdl_kwargs: dict, |
| 59 | head_dim: int, |
| 60 | rope_head_dim: int, |
| 61 | compress_ratio: int, |
| 62 | overlap: bool, |
| 63 | use_fp4_cache: bool, |
| 64 | rms_norm_weight: torch.Tensor, |
| 65 | rms_norm_eps: float, |
| 66 | quant_block: int, |
| 67 | token_stride: int, |
| 68 | scale_dim: int, |
| 69 | ) -> None: |
| 70 | """Shared triton launcher for the fused compress+norm+RoPE+insert path. |
| 71 | |
| 72 | Picks one of the three kernels in this module based on ``head_dim`` and |
| 73 | ``use_fp4_cache``. Identical launch signature for all three. |
| 74 | """ |
| 75 | if head_dim == 512: |
| 76 | kernel = _fused_kv_compress_norm_rope_insert_sparse_attn |
| 77 | num_warps = 4 |
| 78 | kernel_kwargs = {"SANITIZE_CACHE_NANS": _ON_GFX950} |
| 79 | else: |
| 80 | _FUSED_KV_COMPRESS_NORM_ROPE_INSERT_INDEXER_TRITON_KERNEL( |
| 81 | state_cache=state_cache, |
| 82 | num_actual=num_actual, |
| 83 | token_to_req_indices=token_to_req_indices, |
| 84 | positions=positions, |
| 85 | slot_mapping=slot_mapping, |
| 86 | block_table=block_table, |
| 87 | block_size=block_size, |
| 88 | state_width=state_width, |
| 89 | cos_sin_cache=cos_sin_cache, |
| 90 | kv_cache=kv_cache, |
| 91 | k_cache_metadata=k_cache_metadata, |
| 92 | pdl_kwargs=pdl_kwargs, |
| 93 | head_dim=head_dim, |
| 94 | rope_head_dim=rope_head_dim, |
| 95 | compress_ratio=compress_ratio, |
| 96 | overlap=overlap, |
| 97 | use_fp4_cache=use_fp4_cache, |
| 98 | rms_norm_weight=rms_norm_weight, |
| 99 | rms_norm_eps=rms_norm_eps, |
| 100 | quant_block=quant_block, |
| 101 | token_stride=token_stride, |
| 102 | scale_dim=scale_dim, |
| 103 | ) |
| 104 | return |
| 105 | |
| 106 | kernel[(num_actual,)]( |
| 107 | # state cache |
| 108 | state_cache, |
| 109 | state_cache.stride(0), |
| 110 | state_cache.stride(1), |
| 111 | # metadata |
| 112 | token_to_req_indices, |
| 113 | positions, |
| 114 | slot_mapping, |
| 115 | block_table, |
| 116 | block_table.stride(0), |
| 117 | block_size, |
| 118 | # RMSNorm |
| 119 | rms_norm_weight, |
| 120 | rms_norm_eps, |
| 121 | # RoPE |
| 122 | cos_sin_cache, |
| 123 | cos_sin_cache.stride(0), |
| 124 | # KV cache |
| 125 | kv_cache, |
| 126 | k_cache_metadata.slot_mapping, |
| 127 | kv_cache.shape[1], # paged KV cache block size (tokens per block) |
| 128 | # constexprs |
| 129 | HEAD_SIZE=head_dim, |
| 130 | TRITON_BLOCK_SIZE=triton.next_power_of_2(head_dim), |
| 131 | STATE_WIDTH=state_width, |
| 132 | COMPRESS_RATIO=compress_ratio, |
| 133 | OVERLAP=overlap, |
| 134 | ROPE_HEAD_DIM=rope_head_dim, |
| 135 | FP8_MAX=448.0, |
| 136 | QUANT_BLOCK=quant_block, |
| 137 | TOKEN_STRIDE=token_stride, |
| 138 | SCALE_DIM=scale_dim, |
| 139 | KV_BLOCK_STRIDE=kv_cache.stride(0), |
| 140 | num_warps=num_warps, |
| 141 | **kernel_kwargs, |
| 142 | **pdl_kwargs, |
| 143 | ) |
| 144 | |
| 145 | |
| 146 | # ============================================================================= |
| 147 | # DeepseekV4 Attention path (head=512, nope=448 FP8 + rope=64 bf16) |
| 148 | # ============================================================================= |
| 149 | @triton.jit |
| 150 | def _fused_kv_compress_norm_rope_insert_sparse_attn( |
| 151 | # ── state cache (compressor internal state) ── |
| 152 | state_cache_ptr, |
| 153 | state_cache_stride0, |
| 154 | state_cache_stride1, |
| 155 | # ── metadata ── |
| 156 | token_to_req_indices_ptr, |
| 157 | positions_ptr, |
| 158 | slot_mapping_ptr, |
| 159 | block_table_ptr, |
| 160 | block_table_stride, |
| 161 | block_size, |
| 162 | # ── RMSNorm ── |
| 163 | rms_norm_weight_ptr, |
| 164 | rms_norm_eps, |
| 165 | # ── RoPE ── |
| 166 | cos_sin_cache_ptr, |
| 167 | cos_sin_stride, |
| 168 | # ── KV cache output ── |
| 169 | k_cache_ptr, |
| 170 | kv_slot_mapping_ptr, |
| 171 | kv_cache_block_size, |
| 172 | # ── constexprs ── |
| 173 | HEAD_SIZE: tl.constexpr, |
| 174 | TRITON_BLOCK_SIZE: tl.constexpr, |
| 175 | STATE_WIDTH: tl.constexpr, |
| 176 | COMPRESS_RATIO: tl.constexpr, |
| 177 | OVERLAP: tl.constexpr, |
| 178 | ROPE_HEAD_DIM: tl.constexpr, |
| 179 | FP8_MAX: tl.constexpr, # 448.0 |
| 180 | QUANT_BLOCK: tl.constexpr, # 64 for DeepseekV4 |
| 181 | TOKEN_STRIDE: tl.constexpr, # 576 for DeepseekV4 |
| 182 | SCALE_DIM: tl.constexpr, # 8 for DeepseekV4 (7 real + 1 pad) |
| 183 | KV_BLOCK_STRIDE: tl.constexpr, |
| 184 | SANITIZE_CACHE_NANS: tl.constexpr, |
| 185 | ): |
| 186 | """Fused compress → RMSNorm → FP8 quant (nope) → RoPE → bf16 store (rope). |
| 187 | |
| 188 | One program per token; early-exits for non-boundary positions. |
| 189 | |
| 190 | Cache block layout (``block_size`` tokens): |
| 191 | [0, bs*576): token data (448 fp8 + 128 bf16 each) |
| 192 | [bs*576, +bs*8): uint8 UE8M0 scales (7 real + 1 pad each) |
| 193 | """ |
| 194 | token_idx = tl.program_id(0) |
| 195 | |
| 196 | slot_id = tl.load(slot_mapping_ptr + token_idx) |
| 197 | if slot_id < 0: |
| 198 | return |
| 199 | |
| 200 | position = tl.load(positions_ptr + token_idx) |
| 201 | if (position + 1) % COMPRESS_RATIO != 0: |
| 202 | return |
| 203 | |
| 204 | req_idx = tl.load(token_to_req_indices_ptr + token_idx) |
| 205 | |
| 206 | # ── Gather state cache entries ──────────────────────────────────── |
| 207 | start = position - (1 + OVERLAP) * COMPRESS_RATIO + 1 |
| 208 | tokens = tl.arange(0, (1 + OVERLAP) * COMPRESS_RATIO) |
| 209 | pos = start + tokens |
| 210 | mask_pos = pos >= 0 |
| 211 | |
| 212 | block_indices = pos // block_size |
| 213 | block_numbers = tl.load( |
| 214 | block_table_ptr + req_idx * block_table_stride + block_indices, |
| 215 | mask=mask_pos, |
| 216 | other=0, |
| 217 | ) |
| 218 | block_offsets = pos % block_size |
| 219 | head_offset = (tokens >= COMPRESS_RATIO).to(tl.int32) * HEAD_SIZE |
| 220 | |
| 221 | block = tl.arange(0, TRITON_BLOCK_SIZE) |
| 222 | mask = block < HEAD_SIZE |
| 223 | block_numbers_i64 = block_numbers.to(tl.int64) |
| 224 | |
| 225 | # Precomputed row base shared by score and kv loads |
| 226 | row_base = ( |
| 227 | state_cache_ptr |
| 228 | + block_numbers_i64 * state_cache_stride0 |
| 229 | + block_offsets * state_cache_stride1 |
| 230 | + head_offset |
| 231 | ) |
| 232 | |
| 233 | combined_mask = mask_pos[:, None] & mask[None, :] |
| 234 | |
| 235 | # ── Softmax + weighted sum ─────────────────────────────────────── |
| 236 | score = tl.load( |
| 237 | row_base[:, None] + STATE_WIDTH + block[None, :], |
| 238 | mask=combined_mask, |
| 239 | other=float("-inf"), |
| 240 | ) |
| 241 | score = tl.softmax(score, dim=0) |
| 242 | |
| 243 | kv = tl.load( |
| 244 | row_base[:, None] + block[None, :], |
| 245 | mask=combined_mask, |
| 246 | other=0.0, |
| 247 | ) |
| 248 | |
| 249 | compressed_kv = tl.sum(kv * score, axis=0) # [TRITON_BLOCK_SIZE] fp32 |
| 250 | |
| 251 | # ── RMSNorm (fp32 throughout) ────────────────────────────────────── |
| 252 | rms_w = tl.load(rms_norm_weight_ptr + block, mask=mask, other=0.0) |
| 253 | variance = tl.sum(compressed_kv * compressed_kv, axis=0) / HEAD_SIZE |
| 254 | rrms = tl.rsqrt(variance + rms_norm_eps) |
| 255 | normed = compressed_kv * rrms * rms_w |
| 256 | |
| 257 | # ── KV cache pointers ──────────────────────────────────────────── |
| 258 | kv_slot_idx = tl.load(kv_slot_mapping_ptr + token_idx) |
| 259 | if kv_slot_idx < 0: |
| 260 | return |
| 261 | kv_block_idx = kv_slot_idx // kv_cache_block_size |
| 262 | kv_pos_in_block = kv_slot_idx % kv_cache_block_size |
| 263 | |
| 264 | cache_block_ptr = k_cache_ptr + kv_block_idx.to(tl.int64) * KV_BLOCK_STRIDE |
| 265 | fp8_ptr = cache_block_ptr + kv_pos_in_block * TOKEN_STRIDE |
| 266 | scale_ptr = ( |
| 267 | cache_block_ptr |
| 268 | + kv_cache_block_size * TOKEN_STRIDE |
| 269 | + kv_pos_in_block * SCALE_DIM |
| 270 | ) |
| 271 | |
| 272 | NOPE_HEAD_DIM: tl.constexpr = HEAD_SIZE - ROPE_HEAD_DIM # 448 |
| 273 | HALF_ROPE: tl.constexpr = ROPE_HEAD_DIM // 2 # 32 |
| 274 | |
| 275 | # FP8 UE8M0 quant: cast fp32 → bf16 → fp32 before quant to match reference. |
| 276 | N_QUANT_BLOCKS: tl.constexpr = TRITON_BLOCK_SIZE // QUANT_BLOCK |
| 277 | N_NOPE_BLOCKS: tl.constexpr = NOPE_HEAD_DIM // QUANT_BLOCK # 7 |
| 278 | INV_FP8_MAX: tl.constexpr = 1.0 / FP8_MAX |
| 279 | |
| 280 | quant_input = normed.to(tl.bfloat16).to(tl.float32) |
| 281 | quant_2d = tl.reshape(quant_input, (N_QUANT_BLOCKS, QUANT_BLOCK)) |
| 282 | abs_2d = tl.abs(quant_2d) |
| 283 | block_absmax = tl.max(abs_2d, axis=1) # [N_QUANT_BLOCKS] fp32 |
| 284 | block_absmax = tl.maximum(block_absmax, 1e-4) |
| 285 | |
| 286 | raw_scales = block_absmax * INV_FP8_MAX |
| 287 | exponents = tl.ceil(tl.log2(raw_scales)) |
| 288 | inv_scales = tl.exp2(-exponents) |
| 289 | inv_scales_col = tl.reshape(inv_scales, (N_QUANT_BLOCKS, 1)) |
| 290 | x_scaled = quant_2d * inv_scales_col |
| 291 | x_clamped = tl.clamp(x_scaled, -FP8_MAX, FP8_MAX) |
| 292 | x_fp8 = x_clamped.to(tl.float8e4nv) |
| 293 | x_uint8 = x_fp8.to(tl.uint8, bitcast=True) |
| 294 | x_uint8_flat = tl.reshape(x_uint8, (TRITON_BLOCK_SIZE,)) |
| 295 | |
| 296 | nope_mask = block < NOPE_HEAD_DIM |
| 297 | tl.store(fp8_ptr + block, x_uint8_flat, mask=nope_mask) |
| 298 | |
| 299 | scale_idx = tl.arange(0, N_QUANT_BLOCKS) |
| 300 | encoded = exponents + 127.0 |
| 301 | max_encoded: tl.constexpr = 254.0 if SANITIZE_CACHE_NANS else 255.0 |
| 302 | encoded = tl.maximum(tl.minimum(encoded, max_encoded), 0.0) |
| 303 | tl.store( |
| 304 | scale_ptr + scale_idx, |
| 305 | encoded.to(tl.uint8), |
| 306 | mask=scale_idx < N_NOPE_BLOCKS, |
| 307 | ) |
| 308 | tl.store(scale_ptr + N_NOPE_BLOCKS, tl.zeros((), dtype=tl.uint8)) |
| 309 | |
| 310 | # Register-based GPT-J RoPE in fp32. |
| 311 | NUM_PAIRS: tl.constexpr = TRITON_BLOCK_SIZE // 2 |
| 312 | NOPE_PAIRS: tl.constexpr = NOPE_HEAD_DIM // 2 |
| 313 | |
| 314 | pair_2d = tl.reshape(normed, (NUM_PAIRS, 2)) |
| 315 | even, odd = tl.split(pair_2d) # each [NUM_PAIRS] fp32 |
| 316 | |
| 317 | pair_idx = tl.arange(0, NUM_PAIRS) |
| 318 | rope_pair_local = pair_idx - NOPE_PAIRS |
| 319 | is_rope_pair = rope_pair_local >= 0 |
| 320 | cs_idx = tl.maximum(rope_pair_local, 0) |
| 321 | |
| 322 | compressed_pos = (position // COMPRESS_RATIO) * COMPRESS_RATIO |
| 323 | cache_base = cos_sin_cache_ptr + compressed_pos * cos_sin_stride |
| 324 | cos_v = tl.load(cache_base + cs_idx, mask=is_rope_pair, other=1.0) |
| 325 | sin_v = tl.load(cache_base + HALF_ROPE + cs_idx, mask=is_rope_pair, other=0.0) |
| 326 | |
| 327 | new_even = even * cos_v - odd * sin_v |
| 328 | new_odd = odd * cos_v + even * sin_v |
| 329 | result = tl.interleave(new_even, new_odd) # [TRITON_BLOCK_SIZE] fp32 |
| 330 | if SANITIZE_CACHE_NANS: |
| 331 | result = tl.where(result == result, result, 0.0) |
| 332 | |
| 333 | # Store rotated rope portion as bf16 into the cache's bf16 area. |
| 334 | bf16_ptr = (fp8_ptr + NOPE_HEAD_DIM).to(tl.pointer_type(tl.bfloat16)) |
| 335 | rope_local = block - NOPE_HEAD_DIM |
| 336 | is_rope = (block >= NOPE_HEAD_DIM) & mask |
| 337 | tl.store(bf16_ptr + rope_local, result.to(tl.bfloat16), mask=is_rope) |
| 338 | |
| 339 | |
| 340 | # ============================================================================= |
| 341 | # Split kernels variant of the head=512 compressor (deep cr=128 gather). |
| 342 | # - compress gather: instead of launching one program per token, split along |
| 343 | # the head dimension to maximize CU occupancy. The head dimension split |
| 344 | # does not require cross-group reduction |
| 345 | # - finalize norm rope quant store: same as the single pass kernel due to its |
| 346 | # per-token nature |
| 347 | # Mirrors the CUDA cutedsl split kernel where num_splits is occupancy-targeted. |
| 348 | # Currently only tested and validated on ROCm gfx950 |
| 349 | # ============================================================================= |
| 350 | @lru_cache(maxsize=1) |
| 351 | def _n_cu() -> int: |
| 352 | return torch.cuda.get_device_properties(0).multi_processor_count |
| 353 | |
| 354 | |
| 355 | def _pick_compress_num_splits( |
| 356 | num_actual: int, compress_ratio: int, head_dim: int |
| 357 | ) -> int: |
| 358 | """Occupancy-targeted column splits for the cr>=128 head=512 compressor. |
| 359 | |
| 360 | Sizes the per-token fan-out so (estimated computing tokens) * num_splits ~ |
| 361 | #CU, capped by head tiling at a 32-wide min tile, as a power-of-2 divisor of |
| 362 | head_dim. |
| 363 | """ |
| 364 | max_splits = head_dim // 32 |
| 365 | est_compute = max(1, num_actual // compress_ratio) |
| 366 | target = -(-_n_cu() // est_compute) # ceil(#CU / est_compute) |
| 367 | ns = 1 |
| 368 | while ns * 2 <= min(target, max_splits) and head_dim % (ns * 2) == 0: |
| 369 | ns *= 2 |
| 370 | return ns |
| 371 | |
| 372 | |
| 373 | @triton.jit |
| 374 | def _compress_gather_split_sparse_attn( |
| 375 | state_cache_ptr, |
| 376 | state_cache_stride0, |
| 377 | state_cache_stride1, |
| 378 | positions_ptr, |
| 379 | slot_mapping_ptr, |
| 380 | token_to_req_indices_ptr, |
| 381 | block_table_ptr, |
| 382 | block_table_stride, |
| 383 | block_size, |
| 384 | scratch_ptr, |
| 385 | scratch_stride, |
| 386 | HEAD_SIZE: tl.constexpr, |
| 387 | STATE_WIDTH: tl.constexpr, |
| 388 | COMPRESS_RATIO: tl.constexpr, |
| 389 | NUM_SPLITS: tl.constexpr, |
| 390 | HEAD_TILE: tl.constexpr, # HEAD_SIZE // NUM_SPLITS |
| 391 | ): |
| 392 | """Stage 1: per-(token, head-split) compress gather, write to fp32 scratch. |
| 393 | |
| 394 | No-overlap gather (cr>=128) on rows [0, COMPRESS_RATIO) |
| 395 | """ |
| 396 | pid = tl.program_id(0) |
| 397 | token_idx = pid // NUM_SPLITS |
| 398 | split_idx = pid % NUM_SPLITS |
| 399 | |
| 400 | slot_id = tl.load(slot_mapping_ptr + token_idx) |
| 401 | if slot_id < 0: |
| 402 | return |
| 403 | position = tl.load(positions_ptr + token_idx) |
| 404 | if (position + 1) % COMPRESS_RATIO != 0: |
| 405 | return |
| 406 | req_idx = tl.load(token_to_req_indices_ptr + token_idx) |
| 407 | |
| 408 | start = position - COMPRESS_RATIO + 1 |
| 409 | rows = tl.arange(0, COMPRESS_RATIO) |
| 410 | pos = start + rows |
| 411 | mask_pos = pos >= 0 |
| 412 | block_numbers = tl.load( |
| 413 | block_table_ptr + req_idx * block_table_stride + pos // block_size, |
| 414 | mask=mask_pos, |
| 415 | other=0, |
| 416 | ).to(tl.int64) |
| 417 | block_offsets = pos % block_size |
| 418 | |
| 419 | col = split_idx * HEAD_TILE + tl.arange(0, HEAD_TILE) |
| 420 | row_base = ( |
| 421 | state_cache_ptr |
| 422 | + block_numbers * state_cache_stride0 |
| 423 | + block_offsets * state_cache_stride1 |
| 424 | ) |
| 425 | cmask = mask_pos[:, None] |
| 426 | |
| 427 | score = tl.load( |
| 428 | row_base[:, None] + STATE_WIDTH + col[None, :], |
| 429 | mask=cmask, |
| 430 | other=float("-inf"), |
| 431 | ) |
| 432 | score = tl.softmax(score, dim=0) |
| 433 | kv = tl.load(row_base[:, None] + col[None, :], mask=cmask, other=0.0) |
| 434 | compressed = tl.sum(kv * score, axis=0) # [HEAD_TILE] fp32 |
| 435 | tl.store(scratch_ptr + token_idx * scratch_stride + col, compressed) |
| 436 | |
| 437 | |
| 438 | @triton.jit |
| 439 | def _finalize_norm_rope_quant_store_sparse_attn( |
| 440 | scratch_ptr, |
| 441 | scratch_stride, |
| 442 | positions_ptr, |
| 443 | slot_mapping_ptr, |
| 444 | rms_norm_weight_ptr, |
| 445 | rms_norm_eps, |
| 446 | cos_sin_cache_ptr, |
| 447 | cos_sin_stride, |
| 448 | k_cache_ptr, |
| 449 | kv_slot_mapping_ptr, |
| 450 | kv_cache_block_size, |
| 451 | HEAD_SIZE: tl.constexpr, |
| 452 | TRITON_BLOCK_SIZE: tl.constexpr, |
| 453 | COMPRESS_RATIO: tl.constexpr, |
| 454 | ROPE_HEAD_DIM: tl.constexpr, |
| 455 | FP8_MAX: tl.constexpr, |
| 456 | QUANT_BLOCK: tl.constexpr, |
| 457 | TOKEN_STRIDE: tl.constexpr, |
| 458 | SCALE_DIM: tl.constexpr, |
| 459 | KV_BLOCK_STRIDE: tl.constexpr, |
| 460 | SANITIZE_CACHE_NANS: tl.constexpr, |
| 461 | ): |
| 462 | """Stage 2: read compressed_kv[512] from scratch buffer, then |
| 463 | RMSNorm + FP8 quant (nope) + RoPE + bf16 store |
| 464 | """ |
| 465 | token_idx = tl.program_id(0) |
| 466 | slot_id = tl.load(slot_mapping_ptr + token_idx) |
| 467 | if slot_id < 0: |
| 468 | return |
| 469 | position = tl.load(positions_ptr + token_idx) |
| 470 | if (position + 1) % COMPRESS_RATIO != 0: |
| 471 | return |
| 472 | |
| 473 | block = tl.arange(0, TRITON_BLOCK_SIZE) |
| 474 | mask = block < HEAD_SIZE |
| 475 | compressed_kv = tl.load( |
| 476 | scratch_ptr + token_idx * scratch_stride + block, mask=mask, other=0.0 |
| 477 | ) |
| 478 | |
| 479 | rms_w = tl.load(rms_norm_weight_ptr + block, mask=mask, other=0.0) |
| 480 | variance = tl.sum(compressed_kv * compressed_kv, axis=0) / HEAD_SIZE |
| 481 | rrms = tl.rsqrt(variance + rms_norm_eps) |
| 482 | normed = compressed_kv * rrms * rms_w |
| 483 | |
| 484 | kv_slot_idx = tl.load(kv_slot_mapping_ptr + token_idx) |
| 485 | if kv_slot_idx < 0: |
| 486 | return |
| 487 | kv_block_idx = kv_slot_idx // kv_cache_block_size |
| 488 | kv_pos_in_block = kv_slot_idx % kv_cache_block_size |
| 489 | cache_block_ptr = k_cache_ptr + kv_block_idx.to(tl.int64) * KV_BLOCK_STRIDE |
| 490 | fp8_ptr = cache_block_ptr + kv_pos_in_block * TOKEN_STRIDE |
| 491 | scale_ptr = ( |
| 492 | cache_block_ptr |
| 493 | + kv_cache_block_size * TOKEN_STRIDE |
| 494 | + kv_pos_in_block * SCALE_DIM |
| 495 | ) |
| 496 | |
| 497 | NOPE_HEAD_DIM: tl.constexpr = HEAD_SIZE - ROPE_HEAD_DIM |
| 498 | HALF_ROPE: tl.constexpr = ROPE_HEAD_DIM // 2 |
| 499 | N_QUANT_BLOCKS: tl.constexpr = TRITON_BLOCK_SIZE // QUANT_BLOCK |
| 500 | N_NOPE_BLOCKS: tl.constexpr = NOPE_HEAD_DIM // QUANT_BLOCK |
| 501 | INV_FP8_MAX: tl.constexpr = 1.0 / FP8_MAX |
| 502 | |
| 503 | quant_input = normed.to(tl.bfloat16).to(tl.float32) |
| 504 | quant_2d = tl.reshape(quant_input, (N_QUANT_BLOCKS, QUANT_BLOCK)) |
| 505 | block_absmax = tl.maximum(tl.max(tl.abs(quant_2d), axis=1), 1e-4) |
| 506 | raw_scales = block_absmax * INV_FP8_MAX |
| 507 | exponents = tl.ceil(tl.log2(raw_scales)) |
| 508 | inv_scales = tl.exp2(-exponents) |
| 509 | x_scaled = quant_2d * tl.reshape(inv_scales, (N_QUANT_BLOCKS, 1)) |
| 510 | x_clamped = tl.clamp(x_scaled, -FP8_MAX, FP8_MAX) |
| 511 | x_uint8 = tl.reshape( |
| 512 | x_clamped.to(tl.float8e4nv).to(tl.uint8, bitcast=True), |
| 513 | (TRITON_BLOCK_SIZE,), |
| 514 | ) |
| 515 | tl.store(fp8_ptr + block, x_uint8, mask=block < NOPE_HEAD_DIM) |
| 516 | |
| 517 | scale_idx = tl.arange(0, N_QUANT_BLOCKS) |
| 518 | max_encoded: tl.constexpr = 254.0 if SANITIZE_CACHE_NANS else 255.0 |
| 519 | encoded = tl.maximum(tl.minimum(exponents + 127.0, max_encoded), 0.0) |
| 520 | tl.store( |
| 521 | scale_ptr + scale_idx, encoded.to(tl.uint8), mask=scale_idx < N_NOPE_BLOCKS |
| 522 | ) |
| 523 | tl.store(scale_ptr + N_NOPE_BLOCKS, tl.zeros((), dtype=tl.uint8)) |
| 524 | |
| 525 | NUM_PAIRS: tl.constexpr = TRITON_BLOCK_SIZE // 2 |
| 526 | NOPE_PAIRS: tl.constexpr = NOPE_HEAD_DIM // 2 |
| 527 | even, odd = tl.split(tl.reshape(normed, (NUM_PAIRS, 2))) |
| 528 | pair_idx = tl.arange(0, NUM_PAIRS) |
| 529 | rope_pair_local = pair_idx - NOPE_PAIRS |
| 530 | is_rope_pair = rope_pair_local >= 0 |
| 531 | cs_idx = tl.maximum(rope_pair_local, 0) |
| 532 | compressed_pos = (position // COMPRESS_RATIO) * COMPRESS_RATIO |
| 533 | cache_base = cos_sin_cache_ptr + compressed_pos * cos_sin_stride |
| 534 | cos_v = tl.load(cache_base + cs_idx, mask=is_rope_pair, other=1.0) |
| 535 | sin_v = tl.load(cache_base + HALF_ROPE + cs_idx, mask=is_rope_pair, other=0.0) |
| 536 | new_even = even * cos_v - odd * sin_v |
| 537 | new_odd = odd * cos_v + even * sin_v |
| 538 | result = tl.interleave(new_even, new_odd) |
| 539 | if SANITIZE_CACHE_NANS: |
| 540 | result = tl.where(result == result, result, 0.0) |
| 541 | bf16_ptr = (fp8_ptr + NOPE_HEAD_DIM).to(tl.pointer_type(tl.bfloat16)) |
| 542 | rope_local = block - NOPE_HEAD_DIM |
| 543 | is_rope = (block >= NOPE_HEAD_DIM) & mask |
| 544 | tl.store(bf16_ptr + rope_local, result.to(tl.bfloat16), mask=is_rope) |
| 545 | |
| 546 | |
| 547 | def _launch_two_stage_sparse_attn_compressor( |
| 548 | state_cache: torch.Tensor, |
| 549 | token_to_req_indices: torch.Tensor, |
| 550 | positions: torch.Tensor, |
| 551 | slot_mapping: torch.Tensor, |
| 552 | block_table: torch.Tensor, |
| 553 | block_size: int, |
| 554 | state_width: int, |
| 555 | compress_ratio: int, |
| 556 | cos_sin_cache: torch.Tensor, |
| 557 | kv_cache: torch.Tensor, |
| 558 | kv_slot_mapping: torch.Tensor, |
| 559 | rms_norm_weight: torch.Tensor, |
| 560 | rms_norm_eps: float, |
| 561 | quant_block: int, |
| 562 | token_stride: int, |
| 563 | scale_dim: int, |
| 564 | head_dim: int, |
| 565 | rope_head_dim: int, |
| 566 | num_actual: int, |
| 567 | compress_scratch: torch.Tensor, |
| 568 | ) -> None: |
| 569 | num_splits = _pick_compress_num_splits(num_actual, compress_ratio, head_dim) |
| 570 | head_tile = head_dim // num_splits |
| 571 | scratch = compress_scratch[:num_actual] |
| 572 | _compress_gather_split_sparse_attn[(num_actual * num_splits,)]( |
| 573 | state_cache, |
| 574 | state_cache.stride(0), |
| 575 | state_cache.stride(1), |
| 576 | positions, |
| 577 | slot_mapping, |
| 578 | token_to_req_indices, |
| 579 | block_table, |
| 580 | block_table.stride(0), |
| 581 | block_size, |
| 582 | scratch, |
| 583 | scratch.stride(0), |
| 584 | HEAD_SIZE=head_dim, |
| 585 | STATE_WIDTH=state_width, |
| 586 | COMPRESS_RATIO=compress_ratio, |
| 587 | NUM_SPLITS=num_splits, |
| 588 | HEAD_TILE=head_tile, |
| 589 | ) |
| 590 | _finalize_norm_rope_quant_store_sparse_attn[(num_actual,)]( |
| 591 | scratch, |
| 592 | scratch.stride(0), |
| 593 | positions, |
| 594 | slot_mapping, |
| 595 | rms_norm_weight, |
| 596 | rms_norm_eps, |
| 597 | cos_sin_cache, |
| 598 | cos_sin_cache.stride(0), |
| 599 | kv_cache, |
| 600 | kv_slot_mapping, |
| 601 | kv_cache.shape[1], |
| 602 | HEAD_SIZE=head_dim, |
| 603 | TRITON_BLOCK_SIZE=triton.next_power_of_2(head_dim), |
| 604 | COMPRESS_RATIO=compress_ratio, |
| 605 | ROPE_HEAD_DIM=rope_head_dim, |
| 606 | FP8_MAX=448.0, |
| 607 | QUANT_BLOCK=quant_block, |
| 608 | TOKEN_STRIDE=token_stride, |
| 609 | SCALE_DIM=scale_dim, |
| 610 | KV_BLOCK_STRIDE=kv_cache.stride(0), |
| 611 | SANITIZE_CACHE_NANS=_ON_GFX950, |
| 612 | ) |
| 613 | |
| 614 | |
| 615 | def compress_norm_rope_store_two_stage_triton( |
| 616 | state_cache: torch.Tensor, |
| 617 | num_actual: int, |
| 618 | token_to_req_indices: torch.Tensor, |
| 619 | positions: torch.Tensor, |
| 620 | slot_mapping: torch.Tensor, |
| 621 | block_table: torch.Tensor, |
| 622 | block_size: int, |
| 623 | state_width: int, |
| 624 | cos_sin_cache: torch.Tensor, |
| 625 | kv_cache: torch.Tensor, |
| 626 | k_cache_metadata: Any, |
| 627 | pdl_kwargs: dict, |
| 628 | head_dim: int, |
| 629 | rope_head_dim: int, |
| 630 | compress_ratio: int, |
| 631 | overlap: bool, |
| 632 | use_fp4_cache: bool, |
| 633 | rms_norm_weight: torch.Tensor, |
| 634 | rms_norm_eps: float, |
| 635 | quant_block: int, |
| 636 | token_stride: int, |
| 637 | scale_dim: int, |
| 638 | num_decode_tokens: int, |
| 639 | compress_scratch: torch.Tensor, |
| 640 | ) -> None: |
| 641 | """Two-stage split compressor dispatch for head=512 cr>=128 (no-overlap). |
| 642 | |
| 643 | Run the occupancy-fanned two-stage split for prefill [num_decodee_tokens:] |
| 644 | to fill the CUs, and use the original single-pass launcher |
| 645 | for decode [0, num_decode_tokens) |
| 646 | """ |
| 647 | num_decodes = min(max(num_decode_tokens, 0), num_actual) |
| 648 | num_prefills = num_actual - num_decodes |
| 649 | if num_prefills > 0: |
| 650 | _launch_two_stage_sparse_attn_compressor( |
| 651 | state_cache=state_cache, |
| 652 | token_to_req_indices=token_to_req_indices[num_decodes:], |
| 653 | positions=positions[num_decodes:], |
| 654 | slot_mapping=slot_mapping[num_decodes:], |
| 655 | block_table=block_table, |
| 656 | block_size=block_size, |
| 657 | state_width=state_width, |
| 658 | compress_ratio=compress_ratio, |
| 659 | cos_sin_cache=cos_sin_cache, |
| 660 | kv_cache=kv_cache, |
| 661 | kv_slot_mapping=k_cache_metadata.slot_mapping[num_decodes:], |
| 662 | rms_norm_weight=rms_norm_weight, |
| 663 | rms_norm_eps=rms_norm_eps, |
| 664 | quant_block=quant_block, |
| 665 | token_stride=token_stride, |
| 666 | scale_dim=scale_dim, |
| 667 | head_dim=head_dim, |
| 668 | rope_head_dim=rope_head_dim, |
| 669 | num_actual=num_prefills, |
| 670 | compress_scratch=compress_scratch, |
| 671 | ) |
| 672 | if num_decodes > 0: |
| 673 | compress_norm_rope_store_triton( |
| 674 | state_cache=state_cache, |
| 675 | num_actual=num_decodes, |
| 676 | token_to_req_indices=token_to_req_indices, |
| 677 | positions=positions, |
| 678 | slot_mapping=slot_mapping, |
| 679 | block_table=block_table, |
| 680 | block_size=block_size, |
| 681 | state_width=state_width, |
| 682 | cos_sin_cache=cos_sin_cache, |
| 683 | kv_cache=kv_cache, |
| 684 | k_cache_metadata=k_cache_metadata, |
| 685 | pdl_kwargs=pdl_kwargs, |
| 686 | head_dim=head_dim, |
| 687 | rope_head_dim=rope_head_dim, |
| 688 | compress_ratio=compress_ratio, |
| 689 | overlap=overlap, |
| 690 | use_fp4_cache=use_fp4_cache, |
| 691 | rms_norm_weight=rms_norm_weight, |
| 692 | rms_norm_eps=rms_norm_eps, |
| 693 | quant_block=quant_block, |
| 694 | token_stride=token_stride, |
| 695 | scale_dim=scale_dim, |
| 696 | ) |
| 697 | |
| 698 | |
| 699 | # ============================================================================= |
| 700 | # Indexer path (head=128, all FP8, single quant block) |
| 701 | # ============================================================================= |
| 702 | @triton.jit( |
| 703 | do_not_specialize=[ |
| 704 | "state_cache_stride0", |
| 705 | "state_cache_stride1", |
| 706 | "block_table_stride", |
| 707 | "rms_norm_eps", |
| 708 | "cos_sin_stride", |
| 709 | ] |
| 710 | ) |
| 711 | def _fused_kv_compress_norm_rope_insert_indexer_attn( |
| 712 | # ── state cache (compressor internal state) ── |
| 713 | state_cache_ptr, |
| 714 | state_cache_stride0, |
| 715 | state_cache_stride1, |
| 716 | # ── metadata ── |
| 717 | token_to_req_indices_ptr, |
| 718 | positions_ptr, |
| 719 | slot_mapping_ptr, |
| 720 | block_table_ptr, |
| 721 | block_table_stride, |
| 722 | block_size, |
| 723 | # ── RMSNorm ── |
| 724 | rms_norm_weight_ptr, |
| 725 | rms_norm_eps, |
| 726 | # ── RoPE ── |
| 727 | cos_sin_cache_ptr, |
| 728 | cos_sin_stride, |
| 729 | # ── KV cache output ── |
| 730 | k_cache_ptr, |
| 731 | kv_slot_mapping_ptr, |
| 732 | kv_cache_block_size, |
| 733 | # ── constexprs ── |
| 734 | HEAD_SIZE: tl.constexpr, |
| 735 | TRITON_BLOCK_SIZE: tl.constexpr, |
| 736 | STATE_WIDTH: tl.constexpr, |
| 737 | COMPRESS_RATIO: tl.constexpr, |
| 738 | OVERLAP: tl.constexpr, |
| 739 | ROPE_HEAD_DIM: tl.constexpr, |
| 740 | FP8_MAX: tl.constexpr, # 448.0 |
| 741 | QUANT_BLOCK: tl.constexpr, # 128 for indexer |
| 742 | TOKEN_STRIDE: tl.constexpr, # 128 for indexer |
| 743 | SCALE_DIM: tl.constexpr, # 4 for indexer (1 float32) |
| 744 | KV_BLOCK_STRIDE: tl.constexpr, |
| 745 | ): |
| 746 | """Fused compress → RMSNorm → RoPE → FP8 quant → store. |
| 747 | |
| 748 | One program per token; early-exits for non-boundary positions. |
| 749 | |
| 750 | Cache block layout: |
| 751 | [0, bs*128): FP8 data (128 bytes/token) |
| 752 | [bs*128, +bs*4): float32 scales (4 bytes/token) |
| 753 | |
| 754 | For head_dim=128 we have exactly one quant block, so we skip the |
| 755 | [N_QUANT_BLOCKS, QUANT_BLOCK] reshape entirely and use a flat |
| 756 | ``tl.max`` reduction. |
| 757 | """ |
| 758 | token_idx = tl.program_id(0) |
| 759 | |
| 760 | slot_id = tl.load(slot_mapping_ptr + token_idx) |
| 761 | if slot_id < 0: |
| 762 | return |
| 763 | |
| 764 | position = tl.load(positions_ptr + token_idx) |
| 765 | if (position + 1) % COMPRESS_RATIO != 0: |
| 766 | return |
| 767 | |
| 768 | req_idx = tl.load(token_to_req_indices_ptr + token_idx) |
| 769 | |
| 770 | # ── Gather state cache entries ──────────────────────────────────── |
| 771 | start = position - (1 + OVERLAP) * COMPRESS_RATIO + 1 |
| 772 | tokens = tl.arange(0, (1 + OVERLAP) * COMPRESS_RATIO) |
| 773 | pos = start + tokens |
| 774 | mask_pos = pos >= 0 |
| 775 | |
| 776 | block_indices = pos // block_size |
| 777 | block_numbers = tl.load( |
| 778 | block_table_ptr + req_idx * block_table_stride + block_indices, |
| 779 | mask=mask_pos, |
| 780 | other=0, |
| 781 | ) |
| 782 | block_offsets = pos % block_size |
| 783 | head_offset = (tokens >= COMPRESS_RATIO).to(tl.int32) * HEAD_SIZE |
| 784 | |
| 785 | block = tl.arange(0, TRITON_BLOCK_SIZE) |
| 786 | mask = block < HEAD_SIZE |
| 787 | block_numbers_i64 = block_numbers.to(tl.int64) |
| 788 | |
| 789 | row_base = ( |
| 790 | state_cache_ptr |
| 791 | + block_numbers_i64 * state_cache_stride0 |
| 792 | + block_offsets * state_cache_stride1 |
| 793 | + head_offset |
| 794 | ) |
| 795 | |
| 796 | combined_mask = mask_pos[:, None] & mask[None, :] |
| 797 | |
| 798 | score = tl.load( |
| 799 | row_base[:, None] + STATE_WIDTH + block[None, :], |
| 800 | mask=combined_mask, |
| 801 | other=float("-inf"), |
| 802 | ) |
| 803 | score = tl.softmax(score, dim=0) |
| 804 | |
| 805 | kv = tl.load( |
| 806 | row_base[:, None] + block[None, :], |
| 807 | mask=combined_mask, |
| 808 | other=0.0, |
| 809 | ) |
| 810 | |
| 811 | compressed_kv = tl.sum(kv * score, axis=0) # [TRITON_BLOCK_SIZE] fp32 |
| 812 | |
| 813 | # ── RMSNorm (fp32 throughout) ────────────────────────────────────── |
| 814 | rms_w = tl.load(rms_norm_weight_ptr + block, mask=mask, other=0.0) |
| 815 | variance = tl.sum(compressed_kv * compressed_kv, axis=0) / HEAD_SIZE |
| 816 | rrms = tl.rsqrt(variance + rms_norm_eps) |
| 817 | normed = compressed_kv * rrms * rms_w |
| 818 | |
| 819 | # ── KV cache pointers ──────────────────────────────────────────── |
| 820 | kv_slot_idx = tl.load(kv_slot_mapping_ptr + token_idx) |
| 821 | if kv_slot_idx < 0: |
| 822 | return |
| 823 | kv_block_idx = kv_slot_idx // kv_cache_block_size |
| 824 | kv_pos_in_block = kv_slot_idx % kv_cache_block_size |
| 825 | |
| 826 | cache_block_ptr = k_cache_ptr + kv_block_idx.to(tl.int64) * KV_BLOCK_STRIDE |
| 827 | fp8_ptr = cache_block_ptr + kv_pos_in_block * TOKEN_STRIDE |
| 828 | scale_ptr = ( |
| 829 | cache_block_ptr |
| 830 | + kv_cache_block_size * TOKEN_STRIDE |
| 831 | + kv_pos_in_block * SCALE_DIM |
| 832 | ) |
| 833 | |
| 834 | NOPE_HEAD_DIM: tl.constexpr = HEAD_SIZE - ROPE_HEAD_DIM |
| 835 | HALF_ROPE: tl.constexpr = ROPE_HEAD_DIM // 2 |
| 836 | |
| 837 | # ── Register-based GPT-J forward RoPE in fp32 ───────────────────── |
| 838 | NUM_PAIRS: tl.constexpr = TRITON_BLOCK_SIZE // 2 |
| 839 | NOPE_PAIRS: tl.constexpr = NOPE_HEAD_DIM // 2 |
| 840 | |
| 841 | normed_2d = tl.reshape(normed, (NUM_PAIRS, 2)) |
| 842 | even, odd = tl.split(normed_2d) # each [NUM_PAIRS] fp32 |
| 843 | |
| 844 | pair_idx = tl.arange(0, NUM_PAIRS) |
| 845 | rope_pair_local = pair_idx - NOPE_PAIRS |
| 846 | is_rope_pair = rope_pair_local >= 0 |
| 847 | cs_idx = tl.maximum(rope_pair_local, 0) |
| 848 | |
| 849 | compressed_pos = (position // COMPRESS_RATIO) * COMPRESS_RATIO |
| 850 | cache_base = cos_sin_cache_ptr + compressed_pos * cos_sin_stride |
| 851 | cos_v = tl.load(cache_base + cs_idx, mask=is_rope_pair, other=1.0) |
| 852 | sin_v = tl.load(cache_base + HALF_ROPE + cs_idx, mask=is_rope_pair, other=0.0) |
| 853 | |
| 854 | new_even = even * cos_v - odd * sin_v |
| 855 | new_odd = odd * cos_v + even * sin_v |
| 856 | result = tl.interleave(new_even, new_odd) # fp32 |
| 857 | |
| 858 | # ── FP8 UE8M0 quant: single block, flat reduction ──────────────── |
| 859 | tl.static_assert( |
| 860 | TRITON_BLOCK_SIZE == QUANT_BLOCK, |
| 861 | "Indexer expects one quant block (QUANT_BLOCK == TRITON_BLOCK_SIZE)", |
| 862 | ) |
| 863 | INV_FP8_MAX: tl.constexpr = 1.0 / FP8_MAX |
| 864 | |
| 865 | result_bf16 = result.to(tl.bfloat16).to(tl.float32) |
| 866 | absmax = tl.max(tl.abs(result_bf16), axis=0) # scalar |
| 867 | absmax = tl.maximum(absmax, 1e-4) |
| 868 | raw_scale = absmax * INV_FP8_MAX |
| 869 | exponent = tl.ceil(tl.log2(raw_scale)) |
| 870 | inv_scale = tl.exp2(-exponent) |
| 871 | |
| 872 | x_scaled = result_bf16 * inv_scale |
| 873 | x_clamped = tl.clamp(x_scaled, -FP8_MAX, FP8_MAX) |
| 874 | x_fp8 = x_clamped.to(tl.float8e4nv) |
| 875 | x_uint8 = x_fp8.to(tl.uint8, bitcast=True) |
| 876 | |
| 877 | tl.store(fp8_ptr + block, x_uint8, mask=mask) |
| 878 | |
| 879 | # Single float32 scale |
| 880 | scale_val = tl.exp2(exponent) |
| 881 | tl.store(scale_ptr.to(tl.pointer_type(tl.float32)), scale_val) |
| 882 | |
| 883 | |
| 884 | # ============================================================================= |
| 885 | # Indexer path (head=128, MXFP4: 2 nibbles/byte + ue8m0 per 32-elem block) |
| 886 | # ============================================================================= |
| 887 | @triton.jit( |
| 888 | do_not_specialize=[ |
| 889 | "state_cache_stride0", |
| 890 | "state_cache_stride1", |
| 891 | "block_table_stride", |
| 892 | "rms_norm_eps", |
| 893 | "cos_sin_stride", |
| 894 | ] |
| 895 | ) |
| 896 | def _fused_kv_compress_norm_rope_insert_indexer_mxfp4_attn( |
| 897 | # ── state cache (compressor internal state) ── |
| 898 | state_cache_ptr, |
| 899 | state_cache_stride0, |
| 900 | state_cache_stride1, |
| 901 | # ── metadata ── |
| 902 | token_to_req_indices_ptr, |
| 903 | positions_ptr, |
| 904 | slot_mapping_ptr, |
| 905 | block_table_ptr, |
| 906 | block_table_stride, |
| 907 | block_size, |
| 908 | # ── RMSNorm ── |
| 909 | rms_norm_weight_ptr, |
| 910 | rms_norm_eps, |
| 911 | # ── RoPE ── |
| 912 | cos_sin_cache_ptr, |
| 913 | cos_sin_stride, |
| 914 | # ── KV cache output ── |
| 915 | k_cache_ptr, |
| 916 | kv_slot_mapping_ptr, |
| 917 | kv_cache_block_size, |
| 918 | # ── constexprs ── |
| 919 | HEAD_SIZE: tl.constexpr, |
| 920 | TRITON_BLOCK_SIZE: tl.constexpr, |
| 921 | STATE_WIDTH: tl.constexpr, |
| 922 | COMPRESS_RATIO: tl.constexpr, |
| 923 | OVERLAP: tl.constexpr, |
| 924 | ROPE_HEAD_DIM: tl.constexpr, |
| 925 | FP8_MAX: tl.constexpr, # unused for MXFP4 (kept for signature parity) |
| 926 | QUANT_BLOCK: tl.constexpr, # 32 for MXFP4 |
| 927 | TOKEN_STRIDE: tl.constexpr, # HEAD_SIZE // 2 = 64 packed bytes/token |
| 928 | SCALE_DIM: tl.constexpr, # HEAD_SIZE // QUANT_BLOCK = 4 ue8m0 bytes/token |
| 929 | KV_BLOCK_STRIDE: tl.constexpr, |
| 930 | ): |
| 931 | """Fused compress → RMSNorm → RoPE → MXFP4 quant → store. |
| 932 | |
| 933 | One program per token; early-exits for non-boundary positions. |
| 934 | |
| 935 | Cache block layout (``block_size`` tokens per cache block): |
| 936 | [0, bs*TOKEN_STRIDE): packed MXFP4 nibbles (2 values/byte) |
| 937 | [bs*TOKEN_STRIDE, +bs*SCALE_DIM): ue8m0 scale bytes (one per 32-elem block) |
| 938 | |
| 939 | MXFP4 format: |
| 940 | - E2M1 4-bit values packed two per byte (low nibble first, then high). |
| 941 | - Per-32-element block scale = 2^ceil(log2(amax / 6.0)), stored ue8m0 |
| 942 | (byte = exponent + 127). |
| 943 | - Max representable magnitude = 6.0. |
| 944 | """ |
| 945 | token_idx = tl.program_id(0) |
| 946 | |
| 947 | slot_id = tl.load(slot_mapping_ptr + token_idx) |
| 948 | if slot_id < 0: |
| 949 | return |
| 950 | |
| 951 | position = tl.load(positions_ptr + token_idx) |
| 952 | if (position + 1) % COMPRESS_RATIO != 0: |
| 953 | return |
| 954 | |
| 955 | req_idx = tl.load(token_to_req_indices_ptr + token_idx) |
| 956 | |
| 957 | # ── Gather state cache entries ──────────────────────────────────── |
| 958 | start = position - (1 + OVERLAP) * COMPRESS_RATIO + 1 |
| 959 | tokens = tl.arange(0, (1 + OVERLAP) * COMPRESS_RATIO) |
| 960 | pos = start + tokens |
| 961 | mask_pos = pos >= 0 |
| 962 | |
| 963 | block_indices = pos // block_size |
| 964 | block_numbers = tl.load( |
| 965 | block_table_ptr + req_idx * block_table_stride + block_indices, |
| 966 | mask=mask_pos, |
| 967 | other=0, |
| 968 | ) |
| 969 | block_offsets = pos % block_size |
| 970 | head_offset = (tokens >= COMPRESS_RATIO).to(tl.int32) * HEAD_SIZE |
| 971 | |
| 972 | block = tl.arange(0, TRITON_BLOCK_SIZE) |
| 973 | mask = block < HEAD_SIZE |
| 974 | block_numbers_i64 = block_numbers.to(tl.int64) |
| 975 | |
| 976 | row_base = ( |
| 977 | state_cache_ptr |
| 978 | + block_numbers_i64 * state_cache_stride0 |
| 979 | + block_offsets * state_cache_stride1 |
| 980 | + head_offset |
| 981 | ) |
| 982 | |
| 983 | combined_mask = mask_pos[:, None] & mask[None, :] |
| 984 | |
| 985 | score = tl.load( |
| 986 | row_base[:, None] + STATE_WIDTH + block[None, :], |
| 987 | mask=combined_mask, |
| 988 | other=float("-inf"), |
| 989 | ) |
| 990 | score = tl.softmax(score, dim=0) |
| 991 | |
| 992 | kv = tl.load( |
| 993 | row_base[:, None] + block[None, :], |
| 994 | mask=combined_mask, |
| 995 | other=0.0, |
| 996 | ) |
| 997 | |
| 998 | compressed_kv = tl.sum(kv * score, axis=0) # [TRITON_BLOCK_SIZE] fp32 |
| 999 | |
| 1000 | # ── RMSNorm (fp32 throughout) ────────────────────────────────────── |
| 1001 | rms_w = tl.load(rms_norm_weight_ptr + block, mask=mask, other=0.0) |
| 1002 | variance = tl.sum(compressed_kv * compressed_kv, axis=0) / HEAD_SIZE |
| 1003 | rrms = tl.rsqrt(variance + rms_norm_eps) |
| 1004 | normed = compressed_kv * rrms * rms_w |
| 1005 | |
| 1006 | # ── KV cache pointers (segregated: values first, then scales) ──── |
| 1007 | kv_slot_idx = tl.load(kv_slot_mapping_ptr + token_idx) |
| 1008 | if kv_slot_idx < 0: |
| 1009 | return |
| 1010 | kv_block_idx = kv_slot_idx // kv_cache_block_size |
| 1011 | kv_pos_in_block = kv_slot_idx % kv_cache_block_size |
| 1012 | |
| 1013 | cache_block_ptr = k_cache_ptr + kv_block_idx.to(tl.int64) * KV_BLOCK_STRIDE |
| 1014 | val_ptr = cache_block_ptr + kv_pos_in_block * TOKEN_STRIDE |
| 1015 | scale_ptr = ( |
| 1016 | cache_block_ptr |
| 1017 | + kv_cache_block_size * TOKEN_STRIDE |
| 1018 | + kv_pos_in_block * SCALE_DIM |
| 1019 | ) |
| 1020 | |
| 1021 | NOPE_HEAD_DIM: tl.constexpr = HEAD_SIZE - ROPE_HEAD_DIM |
| 1022 | HALF_ROPE: tl.constexpr = ROPE_HEAD_DIM // 2 |
| 1023 | |
| 1024 | # ── Register-based GPT-J forward RoPE in fp32 ───────────────────── |
| 1025 | # We keep the even/odd halves (no tl.interleave afterwards) because the |
| 1026 | # MXFP4 per-block absmax / pack naturally operates on (even, odd) pairs. |
| 1027 | NUM_PAIRS: tl.constexpr = TRITON_BLOCK_SIZE // 2 |
| 1028 | NOPE_PAIRS: tl.constexpr = NOPE_HEAD_DIM // 2 |
| 1029 | |
| 1030 | normed_2d = tl.reshape(normed, (NUM_PAIRS, 2)) |
| 1031 | even, odd = tl.split(normed_2d) # each [NUM_PAIRS] fp32 |
| 1032 | |
| 1033 | pair_idx = tl.arange(0, NUM_PAIRS) |
| 1034 | rope_pair_local = pair_idx - NOPE_PAIRS |
| 1035 | is_rope_pair = rope_pair_local >= 0 |
| 1036 | cs_idx = tl.maximum(rope_pair_local, 0) |
| 1037 | |
| 1038 | compressed_pos = (position // COMPRESS_RATIO) * COMPRESS_RATIO |
| 1039 | cache_base = cos_sin_cache_ptr + compressed_pos * cos_sin_stride |
| 1040 | cos_v = tl.load(cache_base + cs_idx, mask=is_rope_pair, other=1.0) |
| 1041 | sin_v = tl.load(cache_base + HALF_ROPE + cs_idx, mask=is_rope_pair, other=0.0) |
| 1042 | |
| 1043 | new_even = even * cos_v - odd * sin_v |
| 1044 | new_odd = odd * cos_v + even * sin_v |
| 1045 | |
| 1046 | # bf16 roundtrip for parity with reference / Q-side kernel numerics. |
| 1047 | new_even = new_even.to(tl.bfloat16).to(tl.float32) |
| 1048 | new_odd = new_odd.to(tl.bfloat16).to(tl.float32) |
| 1049 | |
| 1050 | # ── MXFP4 quant: tile even/odd halves into (N_BLOCKS, HALF_BLOCK) ── |
| 1051 | # Each MXFP4 block of QUANT_BLOCK elements = HALF_BLOCK consecutive pairs, |
| 1052 | # so (N_BLOCKS, HALF_BLOCK) rows of even/odd each land exactly one block. |
| 1053 | N_QUANT_BLOCKS: tl.constexpr = HEAD_SIZE // QUANT_BLOCK |
| 1054 | HALF_BLOCK: tl.constexpr = QUANT_BLOCK // 2 |
| 1055 | tl.static_assert(TRITON_BLOCK_SIZE == HEAD_SIZE) |
| 1056 | tl.static_assert(HEAD_SIZE % QUANT_BLOCK == 0) |
| 1057 | tl.static_assert(TOKEN_STRIDE == HEAD_SIZE // 2) |
| 1058 | tl.static_assert(SCALE_DIM == N_QUANT_BLOCKS) |
| 1059 | |
| 1060 | even_2d = tl.reshape(new_even, (N_QUANT_BLOCKS, HALF_BLOCK)) |
| 1061 | odd_2d = tl.reshape(new_odd, (N_QUANT_BLOCKS, HALF_BLOCK)) |
| 1062 | |
| 1063 | amax = tl.maximum( |
| 1064 | tl.max(tl.abs(even_2d), axis=1), |
| 1065 | tl.max(tl.abs(odd_2d), axis=1), |
| 1066 | ) |
| 1067 | amax = tl.maximum(amax, 6.0 * (2**-126)) |
| 1068 | |
| 1069 | # ue8m0 block scale: 2^ceil(log2(amax / 6.0)), stored as (exp + 127) byte. |
| 1070 | log2_ratio = tl.ceil(tl.log2(amax * (1.0 / 6.0))) |
| 1071 | log2_ratio = tl.minimum(tl.maximum(log2_ratio, -127.0), 127.0) |
| 1072 | inv_scale = tl.exp2(-log2_ratio) |
| 1073 | ue8m0 = (log2_ratio + 127.0).to(tl.uint8) # [N_QUANT_BLOCKS] |
| 1074 | |
| 1075 | inv_scale_col = tl.reshape(inv_scale, (N_QUANT_BLOCKS, 1)) |
| 1076 | packed = _fp32x2_to_fp4x2( |
| 1077 | even_2d * inv_scale_col, odd_2d * inv_scale_col |
| 1078 | ) # (N_BLOCKS, HALF_BLOCK) uint8 |
| 1079 | packed_flat = tl.reshape(packed, (TOKEN_STRIDE,)) |
| 1080 | |
| 1081 | tl.store(val_ptr + tl.arange(0, TOKEN_STRIDE), packed_flat) |
| 1082 | tl.store(scale_ptr + tl.arange(0, SCALE_DIM), ue8m0) |
| 1083 | |
| 1084 | |
| 1085 | class FusedKVCompressNormRopeInsertIndexerTritonKernel( |
| 1086 | VllmTritonJitKernel["FusedKVCompressNormRopeInsertIndexerTritonKernel.CompileKey"] |
| 1087 | ): |
| 1088 | @dataclass(frozen=True) |
| 1089 | class CompileKey: |
| 1090 | dtype: torch.dtype |
| 1091 | use_fp4_cache: bool |
| 1092 | head_size: int |
| 1093 | triton_block_size: int |
| 1094 | state_width: int |
| 1095 | compress_ratio: int |
| 1096 | overlap: bool |
| 1097 | rope_head_dim: int |
| 1098 | fp8_max: float |
| 1099 | quant_block: int |
| 1100 | token_stride: int |
| 1101 | scale_dim: int |
| 1102 | block_size: int |
| 1103 | kv_cache_block_size: int |
| 1104 | kv_block_stride: int |
| 1105 | |
| 1106 | # Canonical kernel for the launcher's arg_names mapping; the launched |
| 1107 | # variant (fp8/mxfp4, same arg_names) is picked per call in __call__. |
| 1108 | kernel = staticmethod(_fused_kv_compress_norm_rope_insert_indexer_attn) |
| 1109 | |
| 1110 | def dispatch( # type: ignore[override] |
| 1111 | self, |
| 1112 | *, |
| 1113 | dtype: torch.dtype, |
| 1114 | use_fp4_cache: bool, |
| 1115 | head_dim: int, |
| 1116 | rope_head_dim: int, |
| 1117 | compress_ratio: int, |
| 1118 | cache_block_size: int, |
| 1119 | cache_alignment: int, |
| 1120 | runtime_state_width: int | None = None, |
| 1121 | runtime_quant_block: int | None = None, |
| 1122 | runtime_token_stride: int | None = None, |
| 1123 | runtime_scale_dim: int | None = None, |
| 1124 | runtime_kv_block_stride: int | None = None, |
| 1125 | ) -> CompileKey: |
| 1126 | overlap = compress_ratio == 4 |
| 1127 | default_quant_block = 32 if use_fp4_cache else 128 |
| 1128 | quant_block = ( |
| 1129 | runtime_quant_block |
| 1130 | if runtime_quant_block is not None |
| 1131 | else default_quant_block |
| 1132 | ) |
| 1133 | default_token_stride = head_dim // 2 if use_fp4_cache else head_dim |
| 1134 | token_stride = ( |
| 1135 | runtime_token_stride |
| 1136 | if runtime_token_stride is not None |
| 1137 | else default_token_stride |
| 1138 | ) |
| 1139 | default_scale_dim = head_dim // quant_block if use_fp4_cache else 4 |
| 1140 | scale_dim = ( |
| 1141 | runtime_scale_dim if runtime_scale_dim is not None else default_scale_dim |
| 1142 | ) |
| 1143 | raw_kv_cache_block_size = cache_block_size // compress_ratio |
| 1144 | kv_cache_block_size = ( |
| 1145 | raw_kv_cache_block_size if raw_kv_cache_block_size >= 1 else 1 |
| 1146 | ) |
| 1147 | state_block_size = ( |
| 1148 | 4 |
| 1149 | if compress_ratio == 4 |
| 1150 | else 8 |
| 1151 | if compress_ratio == 128 |
| 1152 | else cache_block_size |
| 1153 | ) |
| 1154 | default_kv_block_stride = round_up( |
| 1155 | kv_cache_block_size * (token_stride + scale_dim), |
| 1156 | cache_alignment, |
| 1157 | ) |
| 1158 | kv_block_stride = ( |
| 1159 | runtime_kv_block_stride |
| 1160 | if runtime_kv_block_stride is not None |
| 1161 | else default_kv_block_stride |
| 1162 | ) |
| 1163 | state_width = ( |
| 1164 | runtime_state_width |
| 1165 | if runtime_state_width is not None |
| 1166 | else head_dim * (1 + overlap) |
| 1167 | ) |
| 1168 | return self.CompileKey( |
| 1169 | dtype=dtype, |
| 1170 | use_fp4_cache=use_fp4_cache, |
| 1171 | head_size=head_dim, |
| 1172 | triton_block_size=triton.next_power_of_2(head_dim), |
| 1173 | state_width=state_width, |
| 1174 | compress_ratio=compress_ratio, |
| 1175 | overlap=overlap, |
| 1176 | rope_head_dim=rope_head_dim, |
| 1177 | fp8_max=448.0, |
| 1178 | quant_block=quant_block, |
| 1179 | token_stride=token_stride, |
| 1180 | scale_dim=scale_dim, |
| 1181 | block_size=state_block_size, |
| 1182 | kv_cache_block_size=kv_cache_block_size, |
| 1183 | kv_block_stride=kv_block_stride, |
| 1184 | ) |
| 1185 | |
| 1186 | def get_warmup_keys(self, vllm_config: Any) -> list[CompileKey]: |
| 1187 | hf_config = vllm_config.model_config.hf_config |
| 1188 | if hf_config is None: |
| 1189 | return [] |
| 1190 | |
| 1191 | cache_block_size = vllm_config.cache_config.block_size |
| 1192 | from vllm.v1.attention.backends.mla.indexer import ( |
| 1193 | dsa_indexer_uses_fp4, |
| 1194 | ) |
| 1195 | |
| 1196 | use_fp4_cache = dsa_indexer_uses_fp4(vllm_config) |
| 1197 | head_dim = int(getattr(hf_config, "index_head_dim", 0) or 0) |
| 1198 | rope_head_dim = int(getattr(hf_config, "qk_rope_head_dim", 0) or 0) |
| 1199 | if head_dim <= 0 or rope_head_dim <= 0 or cache_block_size <= 0: |
| 1200 | return [] |
| 1201 | |
| 1202 | cache_dtype = vllm_config.cache_config.cache_dtype |
| 1203 | cache_alignment = 576 if cache_dtype == "fp8_ds_mla" else 512 |
| 1204 | return self._trace_dispatch(self.dispatch)( |
| 1205 | dtype=vllm_config.model_config.dtype, |
| 1206 | use_fp4_cache=use_fp4_cache, |
| 1207 | head_dim=head_dim, |
| 1208 | rope_head_dim=rope_head_dim, |
| 1209 | compress_ratio=4, |
| 1210 | cache_block_size=cache_block_size, |
| 1211 | cache_alignment=cache_alignment, |
| 1212 | ) |
| 1213 | |
| 1214 | def warmup_inputs(self, compile_key: CompileKey) -> dict[str, Any]: |
| 1215 | fp32_ptr = TritonWarmupTensor(torch.float32, shape=(1, 1)) |
| 1216 | int32_ptr = TritonWarmupTensor(torch.int32) |
| 1217 | int64_ptr = TritonWarmupTensor(torch.int64) |
| 1218 | # kv_cache supplies kv_cache_block_size (shape[1]) and KV_BLOCK_STRIDE |
| 1219 | # (stride(0)); reproduce both so warmup and launch specialize identically. |
| 1220 | kv_cache = TritonWarmupTensor( |
| 1221 | torch.uint8, |
| 1222 | shape=(1, compile_key.kv_cache_block_size, 1), |
| 1223 | strides=(compile_key.kv_block_stride, 1, 1), |
| 1224 | ) |
| 1225 | return dict( |
| 1226 | state_cache=fp32_ptr, |
| 1227 | num_actual=1, |
| 1228 | token_to_req_indices=int32_ptr, |
| 1229 | positions=int64_ptr, |
| 1230 | slot_mapping=int64_ptr, |
| 1231 | block_table=int32_ptr, |
| 1232 | block_size=compile_key.block_size, |
| 1233 | state_width=compile_key.state_width, |
| 1234 | cos_sin_cache=fp32_ptr, |
| 1235 | kv_cache=kv_cache, |
| 1236 | k_cache_metadata=SimpleNamespace(slot_mapping=int64_ptr), |
| 1237 | pdl_kwargs={}, |
| 1238 | head_dim=compile_key.head_size, |
| 1239 | rope_head_dim=compile_key.rope_head_dim, |
| 1240 | compress_ratio=compile_key.compress_ratio, |
| 1241 | overlap=compile_key.overlap, |
| 1242 | use_fp4_cache=compile_key.use_fp4_cache, |
| 1243 | rms_norm_weight=TritonWarmupTensor( |
| 1244 | compile_key.dtype, |
| 1245 | shape=(compile_key.head_size,), |
| 1246 | ), |
| 1247 | rms_norm_eps=1e-6, |
| 1248 | quant_block=compile_key.quant_block, |
| 1249 | token_stride=compile_key.token_stride, |
| 1250 | scale_dim=compile_key.scale_dim, |
| 1251 | ) |
| 1252 | |
| 1253 | @kernel_launcher |
| 1254 | def __call__( |
| 1255 | self, |
| 1256 | *, |
| 1257 | state_cache: torch.Tensor, |
| 1258 | num_actual: int, |
| 1259 | token_to_req_indices: torch.Tensor, |
| 1260 | positions: torch.Tensor, |
| 1261 | slot_mapping: torch.Tensor, |
| 1262 | block_table: torch.Tensor, |
| 1263 | block_size: int, |
| 1264 | state_width: int, |
| 1265 | cos_sin_cache: torch.Tensor, |
| 1266 | kv_cache: torch.Tensor, |
| 1267 | k_cache_metadata: Any, |
| 1268 | pdl_kwargs: dict, |
| 1269 | head_dim: int, |
| 1270 | rope_head_dim: int, |
| 1271 | compress_ratio: int, |
| 1272 | overlap: bool, |
| 1273 | use_fp4_cache: bool, |
| 1274 | rms_norm_weight: torch.Tensor, |
| 1275 | rms_norm_eps: float, |
| 1276 | quant_block: int, |
| 1277 | token_stride: int, |
| 1278 | scale_dim: int, |
| 1279 | ) -> LaunchSpec: |
| 1280 | return (num_actual,), dict( |
| 1281 | kernel=( |
| 1282 | _fused_kv_compress_norm_rope_insert_indexer_mxfp4_attn |
| 1283 | if use_fp4_cache |
| 1284 | else _fused_kv_compress_norm_rope_insert_indexer_attn |
| 1285 | ), |
| 1286 | state_cache_stride0=state_cache.stride(0), |
| 1287 | state_cache_stride1=state_cache.stride(1), |
| 1288 | block_table_stride=block_table.stride(0), |
| 1289 | cos_sin_stride=cos_sin_cache.stride(0), |
| 1290 | k_cache_ptr=kv_cache, |
| 1291 | kv_slot_mapping_ptr=k_cache_metadata.slot_mapping, |
| 1292 | kv_cache_block_size=kv_cache.shape[1], |
| 1293 | HEAD_SIZE=head_dim, |
| 1294 | TRITON_BLOCK_SIZE=triton.next_power_of_2(head_dim), |
| 1295 | STATE_WIDTH=state_width, |
| 1296 | COMPRESS_RATIO=compress_ratio, |
| 1297 | OVERLAP=overlap, |
| 1298 | ROPE_HEAD_DIM=rope_head_dim, |
| 1299 | FP8_MAX=448.0, |
| 1300 | QUANT_BLOCK=quant_block, |
| 1301 | TOKEN_STRIDE=token_stride, |
| 1302 | SCALE_DIM=scale_dim, |
| 1303 | KV_BLOCK_STRIDE=kv_cache.stride(0), |
| 1304 | num_warps=1, |
| 1305 | **pdl_kwargs, |
| 1306 | ) |
| 1307 | |
| 1308 | |
| 1309 | _FUSED_KV_COMPRESS_NORM_ROPE_INSERT_INDEXER_TRITON_KERNEL = ( |
| 1310 | FusedKVCompressNormRopeInsertIndexerTritonKernel() |
| 1311 | ) |