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1 // Adapted from
2 // https://github.com/sgl-project/sglang/tree/main/sgl-kernel/csrc/cpu
3
4 // clang-format off
5
6 #include <torch/all.h>
7
8 #include "gemm.h"
9 #include "vec.h"
10
11 namespace {
12
13 #define BLOCK_N block_size_n()
14 #define BLOCK_M 128
15
16 template <bool sym_quant_act>
17 struct ActDtype;
18 template <>
19 struct ActDtype<true> {
20 using type = int8_t;
21 };
22 template <>
23 struct ActDtype<false> {
24 using type = uint8_t;
25 };
26
27 #if defined(CPU_CAPABILITY_AVX512)
28 struct alignas(32) m256i_wrapper {
29 __m256i data;
30 };
31
32 inline std::array<m256i_wrapper, 2> load_zps_4vnni(const int8_t* __restrict__ zps) {
33 // broadcast 01234567 to
34 // 01234567012345670123456701234567
35 __m256i vzps_low = _mm256_set1_epi64x(*reinterpret_cast<const long*>(zps));
36 __m256i vzps_high = _mm256_set1_epi64x(*reinterpret_cast<const long*>(zps + 8));
37 // shuffle from
38 // 01234567012345670123456701234567
39 // to
40 // 00001111222233334444555566667777
41 __m256i shuffle_mask =
42 _mm256_set_epi8(7, 7, 7, 7, 6, 6, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 3, 3, 3, 3, 2, 2, 2, 2, 1, 1, 1, 1, 0, 0, 0, 0);
43 vzps_low = _mm256_shuffle_epi8(vzps_low, shuffle_mask);
44 vzps_high = _mm256_shuffle_epi8(vzps_high, shuffle_mask);
45 m256i_wrapper vzps_low_wp, vzps_high_wp;
46 vzps_low_wp.data = vzps_low;
47 vzps_high_wp.data = vzps_high;
48 return {vzps_low_wp, vzps_high_wp};
49 }
50
51 inline std::array<m256i_wrapper, 2> load_uint4_as_int8(const uint8_t* __restrict__ qB) {
52 __m256i packed = _mm256_loadu_si256(reinterpret_cast<const __m256i*>(qB));
53 const __m256i low_mask = _mm256_set1_epi8(0x0f);
54 __m256i high = _mm256_srli_epi16(packed, 4);
55 high = _mm256_and_si256(high, low_mask);
56 __m256i low = _mm256_and_si256(packed, low_mask);
57 m256i_wrapper low_wp, high_wp;
58 low_wp.data = low;
59 high_wp.data = high;
60 return {low_wp, high_wp};
61 }
62
63 template <int64_t N, int64_t ldb>
64 void _dequant_weight_zp_only(const uint8_t* __restrict__ B, int8_t* dqB, const int8_t* __restrict__ qzeros, int64_t K) {
65 // unpack weight int8 -> two int4
66 // subtract zero point
67 // B shape = [K, ldb] = [K, N / 2], actual shape = [K / 4, N / 2, 4]
68 // dqB shape = [K, N], actual shape = [K / 4, N, 4]
69 #pragma GCC unroll 2
70 for (int n = 0; n < N; n += 16) {
71 auto [zps_low_wp, zps_high_wp] = load_zps_4vnni(&qzeros[n]);
72 auto zps_low = zps_low_wp.data;
73 auto zps_high = zps_high_wp.data;
74 for (int k = 0; k < K; k += 4) {
75 auto [vb_low_wp, vb_high_wp] = load_uint4_as_int8(B + ldb * k + n / 2 * 4);
76 auto vb_low = vb_low_wp.data;
77 auto vb_high = vb_high_wp.data;
78 vb_high = _mm256_sub_epi8(vb_high, zps_high);
79 vb_low = _mm256_sub_epi8(vb_low, zps_low);
80 // store vb to B
81 _mm256_storeu_si256(reinterpret_cast<__m256i_u*>(dqB + N * k + n * 4), vb_low);
82 _mm256_storeu_si256(reinterpret_cast<__m256i_u*>(dqB + N * k + (n + 8) * 4), vb_high);
83 }
84 }
85 }
86
87 template <bool accum, int64_t N, bool sym_quant_act>
88 void _dequant_and_store(
89 float* __restrict__ output,
90 const int32_t* __restrict__ input,
91 const float* __restrict__ scale_a,
92 const int32_t* __restrict__ zp_a,
93 const float* __restrict__ scale_b,
94 const int32_t* __restrict__ comp_b,
95 int M,
96 int ldi,
97 int ldo,
98 int ldsa = 1) {
99 for (int m = 0; m < M; ++m) {
100 float a_scale = *(scale_a + m * ldsa);
101 __m512 va_scale = _mm512_set1_ps(a_scale);
102 int32_t a_zp;
103 __m512i va_zp;
104 if constexpr (!sym_quant_act) {
105 a_zp = *(zp_a + m * ldsa);
106 va_zp = _mm512_set1_epi32(a_zp);
107 }
108 int n = 0;
109 #pragma GCC unroll 2
110 for (; n < N; n += 16) {
111 __m512i vc = _mm512_loadu_si512(input + m * ldi + n);
112 if constexpr (!sym_quant_act) {
113 __m512i vb_comp = _mm512_loadu_si512(comp_b + n);
114 vc = _mm512_sub_epi32(vc, _mm512_mullo_epi32(vb_comp, va_zp));
115 }
116 __m512 vc_f = _mm512_cvtepi32_ps(vc);
117 __m512 vc_f_mul = _mm512_mul_ps(vc_f, va_scale);
118 __m512 vb_s = _mm512_loadu_ps(scale_b + n);
119 vc_f_mul = _mm512_mul_ps(vc_f_mul, vb_s);
120 if constexpr (accum) {
121 __m512 vo = _mm512_loadu_ps(output + m * ldo + n);
122 _mm512_storeu_ps(output + m * ldo + n, _mm512_add_ps(vo, vc_f_mul));
123 } else {
124 _mm512_storeu_ps(output + m * ldo + n, vc_f_mul);
125 }
126 }
127 for (; n < N; ++n) {
128 float dq_val;
129 if constexpr (sym_quant_act) {
130 dq_val = (float)input[m * ldi + n] * a_scale * scale_b[n];
131 } else {
132 dq_val = (float)(input[m * ldi + n] - a_zp * comp_b[n]) * a_scale * scale_b[n];
133 }
134 if constexpr (accum) {
135 output[m * ldo + n] += dq_val;
136 } else {
137 output[m * ldo + n] = dq_val;
138 }
139 }
140 }
141 }
142
143 #else
144 template <int64_t N, int64_t ldb>
145 void _dequant_weight_zp_only(const uint8_t* B, int8_t* dqB, const int8_t* qzeros, int64_t K) {
146 // B shape = [K, N / 2]
147 // dqB shape = [K, N]
148 for (int k = 0; k < K; ++k) {
149 for (int n = 0; n < N / 2; ++n) {
150 int32_t b = (int32_t)B[k * ldb + n];
151 dqB[k * N + n * 2] = (b & 0xf) - qzeros[n];
152 dqB[k * N + n * 2 + 1] = (b >> 4) - qzeros[n];
153 }
154 }
155 }
156 #endif
157
158 #if defined(CPU_CAPABILITY_AVX512)
159 inline __m512i combine_m256i(__m256i a, __m256i b) {
160 __m512i c = _mm512_castsi256_si512(a);
161 return _mm512_inserti64x4(c, b, 1);
162 }
163
164 inline __m512i combine_m256i(std::array<m256i_wrapper, 2> two_256) {
165 return combine_m256i(two_256[0].data, two_256[1].data);
166 }
167
168 // negate elements in a according to b's sign
169 static inline __m512i _mm512_sign_epi8(__m512i a, __m512i b) {
170 __m512i zero = _mm512_setzero_si512();
171 __mmask64 blt0 = _mm512_movepi8_mask(b);
172 return _mm512_mask_sub_epi8(a, blt0, zero, a);
173 }
174
175 template <int64_t M, int64_t N, int64_t ldb, bool sym_quant_act>
176 void _dequant_gemm_accum_small_M(
177 float* __restrict__ C,
178 const uint8_t* A,
179 const float* scales_a,
180 const int32_t* qzeros_a,
181 const uint8_t* B,
182 const float* scales_b,
183 const int8_t* qzeros_b,
184 int64_t K,
185 int64_t lda,
186 int64_t ldc) {
187 // if sym_quant_act is true, A pointer type is passed in as uint8_t* but actually int8_t*.
188
189 constexpr int COLS = N / 16;
190 // Computing compensation is faster than loading it for small M
191 // because it's memory bound.
192 __m512i ones = _mm512_set1_epi8(1); // used for computing compensation
193 __m512i va;
194 __m512i vb[COLS];
195 __m512i vc[M * COLS];
196 __m512 vscales[COLS];
197 __m512i vzps[COLS];
198 __m512i vcompensate[COLS];
199
200 // Load scales and zps
201 Unroll<COLS>{}([&](auto i) {
202 vscales[i] = _mm512_loadu_ps(scales_b + i * 16);
203 vzps[i] = combine_m256i(load_zps_4vnni(qzeros_b + i * 16));
204 if constexpr (!sym_quant_act) {
205 vcompensate[i] = _mm512_setzero_epi32();
206 }
207 });
208 Unroll<M * COLS>{}([&](auto i) { vc[i] = _mm512_setzero_epi32(); });
209
210 auto compute = [&](auto i, int k) {
211 constexpr const int row = i / COLS;
212 constexpr const int col = i % COLS;
213
214 if constexpr (col == 0) {
215 va = _mm512_set1_epi32(*(int32_t*)(A + row * lda + k));
216 }
217
218 if constexpr (row == 0) {
219 int B_offset = k * ldb + col * 16 * 2;
220 vb[col] = combine_m256i(load_uint4_as_int8(B + B_offset));
221 vb[col] = _mm512_sub_epi8(vb[col], vzps[col]);
222 if constexpr (!sym_quant_act) {
223 vcompensate[col] = _mm512_dpbusd_epi32(vcompensate[col], ones, vb[col]);
224 }
225 _mm_prefetch(B + B_offset + 128 * ldb, _MM_HINT_T0);
226 }
227 if constexpr (sym_quant_act) {
228 auto vsb = _mm512_sign_epi8(vb[col], va);
229 auto vabsa = _mm512_sign_epi8(va, va);
230 vc[i] = _mm512_dpbusds_epi32(vc[i], vabsa, vsb);
231 } else {
232 vc[i] = _mm512_dpbusd_epi32(vc[i], va, vb[col]);
233 }
234 };
235
236 // Accumulate along k
237 constexpr const int unroll = 4;
238 int k = 0;
239 for (; k < K / 4 / unroll; k++) {
240 Unroll<unroll>{}([&](auto i) { Unroll<M * COLS>{}(compute, 4 * (k * unroll + i)); });
241 }
242 k *= 4 * unroll;
243 for (; k < K; k += 4) {
244 Unroll<M * COLS>{}(compute, k);
245 }
246
247 // Store to C
248 auto store = [&](auto i) {
249 constexpr const int row = i / COLS;
250 constexpr const int col = i % COLS;
251 // compute (qC - compensate * zp_a) * scale_a * scale_b
252 __m512 vc_float;
253 if constexpr (!sym_quant_act) {
254 vc[i] = _mm512_sub_epi32(vc[i], _mm512_mullo_epi32(vcompensate[col], _mm512_set1_epi32(*(qzeros_a + row))));
255 }
256 vc_float = _mm512_cvtepi32_ps(vc[i]);
257 vc_float = _mm512_mul_ps(vc_float, _mm512_set1_ps(*(scales_a + row)));
258
259 vc_float = _mm512_mul_ps(vc_float, vscales[col]);
260 auto vc_old = _mm512_loadu_ps(C + row * ldc + col * 16);
261 vc_float = _mm512_add_ps(vc_float, vc_old);
262 _mm512_storeu_ps(C + row * ldc + col * 16, vc_float);
263 };
264 Unroll<M * COLS>{}(store);
265 }
266
267 #define CALL_DEQUANT_GEMM_ACCUM_SMALL_M(M) \
268 _dequant_gemm_accum_small_M<M, N, ldb, sym_quant_act>(C, A, scales_a, qzeros_a, B, scales_b, qzeros_b, K, lda, ldc);
269 #endif
270
271 template <int64_t N, int64_t ldb>
272 inline int32_t load_uint4_vnni(const uint8_t* __restrict__ B, int64_t k, int64_t n) {
273 // B is packed as [_block_k / 4, N / 2, 4] for VNNI4. Each byte stores two
274 // columns from adjacent 8-column groups for one K lane.
275 constexpr int64_t n_group_size = 8;
276 constexpr int64_t vnni_size = 4;
277 static_assert(N % (2 * n_group_size) == 0);
278
279 int64_t n_group = n / n_group_size;
280 int64_t ni = n % n_group_size;
281 int64_t ki = k % vnni_size;
282 int64_t k_base = k - ki;
283 int64_t packed_n = (n_group / 2) * n_group_size + ni;
284 uint8_t packed = B[k_base * ldb + packed_n * vnni_size + ki];
285 return (n_group % 2 == 0) ? (packed & 0x0f) : ((packed >> 4) & 0x0f);
286 }
287
288 #if defined(CPU_CAPABILITY_RVV)
289 template <int64_t N, int64_t ldb, int group>
290 inline fixed_i8x8_t load_uint4_as_int8_rvv(const uint8_t* __restrict__ B, int64_t k) {
291 constexpr int64_t n_group_size = 8;
292 constexpr int64_t vnni_size = 4;
293 static_assert(N == 32);
294 static_assert(ldb == N / 2);
295 static_assert(group >= 0 && group < N / n_group_size);
296
297 // Unpack: gather 8 packed int4 values from the VNNI4 layout.
298 const int64_t ki = k % vnni_size;
299 const int64_t k_base = k - ki;
300 constexpr int64_t packed_group = group / 2;
301 const uint8_t* packed_ptr = B + k_base * ldb + packed_group * n_group_size * vnni_size + ki;
302
303 fixed_u8x8_t packed = RVVI(__riscv_vlse8_v_u8, LMUL_64)(packed_ptr, vnni_size, n_group_size);
304 if constexpr (group % 2 == 1) {
305 packed = RVVI(__riscv_vsrl_vx_u8, LMUL_64)(packed, 4, n_group_size);
306 }
307 fixed_u8x8_t nibbles = RVVI(__riscv_vand_vx_u8, LMUL_64)(packed, 0x0f, n_group_size);
308 return RVVI4(__riscv_vreinterpret_v_u8, LMUL_64, _i8, LMUL_64)(nibbles);
309 }
310
311 inline fixed_i32x8_t gemm_accum_uint8_int8_rvv(fixed_i32x8_t acc, uint8_t a, fixed_i8x8_t b) {
312 constexpr int64_t vl = 8;
313 fixed_i16x8_t b_i16 = RVVI(__riscv_vsext_vf2_i16, LMUL_128)(b, vl);
314 return RVVI(__riscv_vwmacc_vx_i32, LMUL_256)(acc, static_cast<int16_t>(a), b_i16, vl);
315 }
316
317 template <int64_t N, int64_t ldb, int group>
318 inline fixed_i32x8_t gemm_accum_uint4_rvv(
319 fixed_i32x8_t acc,
320 const uint8_t* __restrict__ B,
321 const int8_t* __restrict__ qzeros_b,
322 uint8_t a,
323 int64_t k) {
324 constexpr int64_t n_group_size = 8;
325 fixed_i8x8_t b = load_uint4_as_int8_rvv<N, ldb, group>(B, k);
326 fixed_i8x8_t qzeros =
327 RVVI(__riscv_vle8_v_i8, LMUL_64)(qzeros_b + group * n_group_size, n_group_size);
328 b = RVVI(__riscv_vsub_vv_i8, LMUL_64)(b, qzeros, n_group_size);
329 return gemm_accum_uint8_int8_rvv(acc, a, b);
330 }
331
332 template <int group>
333 inline void _dequant_and_store_rvv(
334 float* __restrict__ C,
335 fixed_i32x8_t acc,
336 const float* __restrict__ scales_a,
337 const int32_t* __restrict__ qzeros_a,
338 const float* __restrict__ scales_b,
339 const int32_t* __restrict__ compensation,
340 int64_t m,
341 int64_t ldc) {
342 constexpr int64_t n_group_size = 8;
343 constexpr int64_t n = group * n_group_size;
344 constexpr int64_t vl = n_group_size;
345
346 // Dequant compensation: remove activation zero-point contribution.
347 fixed_i32x8_t comp = RVVI(__riscv_vle32_v_i32, LMUL_256)(compensation + n, vl);
348 fixed_i32x8_t zp_comp = RVVI(__riscv_vmul_vx_i32, LMUL_256)(comp, qzeros_a[m], vl);
349 acc = RVVI(__riscv_vsub_vv_i32, LMUL_256)(acc, zp_comp, vl);
350
351 // Scale: convert int32 accumulators to fp32 and apply activation/weight scales.
352 fixed_fp32x8_t acc_f = RVVI(__riscv_vfcvt_f_x_v_f32, LMUL_256)(acc, vl);
353 acc_f = RVVI(__riscv_vfmul_vf_f32, LMUL_256)(acc_f, scales_a[m], vl);
354 fixed_fp32x8_t scale_b = RVVI(__riscv_vle32_v_f32, LMUL_256)(scales_b + n, vl);
355 acc_f = RVVI(__riscv_vfmul_vv_f32, LMUL_256)(acc_f, scale_b, vl);
356
357 // Store: accumulate into the float scratch buffer that already holds bias/zero.
358 float* c_ptr = C + m * ldc + n;
359 fixed_fp32x8_t c_old = RVVI(__riscv_vle32_v_f32, LMUL_256)(c_ptr, vl);
360 fixed_fp32x8_t c_new = RVVI(__riscv_vfadd_vv_f32, LMUL_256)(c_old, acc_f, vl);
361 RVVI(__riscv_vse32_v_f32, LMUL_256)(c_ptr, c_new, vl);
362 }
363
364 template <int64_t N, int64_t ldb>
365 void _dequant_gemm_accum_rvv(
366 float* __restrict__ C,
367 const uint8_t* __restrict__ A,
368 const float* __restrict__ scales_a,
369 const int32_t* __restrict__ qzeros_a,
370 const uint8_t* __restrict__ B,
371 const float* __restrict__ scales_b,
372 const int8_t* __restrict__ qzeros_b,
373 const int32_t* __restrict__ compensation,
374 int64_t M,
375 int64_t K,
376 int64_t lda,
377 int64_t ldc) {
378 static_assert(N == 32);
379 static_assert(ldb == N / 2);
380 constexpr int64_t vl = 8;
381
382 // Accumulate one C row over the 32-column block.
383 for (int64_t m = 0; m < M; ++m) {
384 fixed_i32x8_t acc0 = RVVI(__riscv_vmv_v_x_i32, LMUL_256)(0, vl);
385 fixed_i32x8_t acc1 = RVVI(__riscv_vmv_v_x_i32, LMUL_256)(0, vl);
386 fixed_i32x8_t acc2 = RVVI(__riscv_vmv_v_x_i32, LMUL_256)(0, vl);
387 fixed_i32x8_t acc3 = RVVI(__riscv_vmv_v_x_i32, LMUL_256)(0, vl);
388 // A[m][k] @ B[k][0:32] -> acc[m][0:32]
389 for (int64_t k = 0; k < K; ++k) {
390 // GEMM K step: one scalar activation updates four 8-column RVV tiles.
391 const uint8_t a = A[m * lda + k];
392 acc0 = gemm_accum_uint4_rvv<N, ldb, 0>(acc0, B, qzeros_b, a, k);
393 acc1 = gemm_accum_uint4_rvv<N, ldb, 1>(acc1, B, qzeros_b, a, k);
394 acc2 = gemm_accum_uint4_rvv<N, ldb, 2>(acc2, B, qzeros_b, a, k);
395 acc3 = gemm_accum_uint4_rvv<N, ldb, 3>(acc3, B, qzeros_b, a, k);
396 }
397
398 // Dequant/scale/store each 8-column group back into C.
399 _dequant_and_store_rvv<0>(C, acc0, scales_a, qzeros_a, scales_b, compensation, m, ldc);
400 _dequant_and_store_rvv<1>(C, acc1, scales_a, qzeros_a, scales_b, compensation, m, ldc);
401 _dequant_and_store_rvv<2>(C, acc2, scales_a, qzeros_a, scales_b, compensation, m, ldc);
402 _dequant_and_store_rvv<3>(C, acc3, scales_a, qzeros_a, scales_b, compensation, m, ldc);
403 }
404 }
405 #endif
406
407 template <int64_t N, int64_t ldb, bool sym_quant_act>
408 void _dequant_gemm_accum(
409 float* C,
410 const uint8_t* A,
411 const float* scales_a,
412 const int32_t* qzeros_a,
413 const uint8_t* B,
414 const float* scales_b,
415 const int8_t* qzeros_b,
416 const int32_t* compensation,
417 int8_t* dqB,
418 int64_t M,
419 int64_t K,
420 int64_t lda,
421 int64_t ldc,
422 bool use_brgemm) {
423 // Compute GEMM int8 * int8 -> int32
424 // dequant result to float by applying scales/qzeros
425 #if defined(CPU_CAPABILITY_AVX512)
426 if (!use_brgemm) {
427 switch (M) {
428 case 1:
429 CALL_DEQUANT_GEMM_ACCUM_SMALL_M(1);
430 break;
431 case 2:
432 CALL_DEQUANT_GEMM_ACCUM_SMALL_M(2);
433 break;
434 case 3:
435 CALL_DEQUANT_GEMM_ACCUM_SMALL_M(3);
436 break;
437 case 4:
438 CALL_DEQUANT_GEMM_ACCUM_SMALL_M(4);
439 break;
440 default:
441 TORCH_CHECK(false, "tinygemm_kernel: unexpected M for AVX path!");
442 }
443 return;
444 }
445
446 _dequant_weight_zp_only<N, ldb>(B, dqB, qzeros_b, K);
447 using Tin = typename ActDtype<sym_quant_act>::type;
448 Tin* A_ptr = (Tin*)A;
449 if (use_brgemm) {
450 int32_t C_i32[M * N];
451 at::native::cpublas::brgemm(
452 M, N, K, lda, N /*ldb*/, N /*ldc*/, false /* add_C */, A_ptr, dqB, C_i32, true /* is_vnni */);
453 _mm_prefetch(B + N * K / 2, _MM_HINT_T0);
454 _mm_prefetch(A + K, _MM_HINT_T0);
455 _dequant_and_store<true, N, sym_quant_act>(
456 C, C_i32, scales_a, qzeros_a, scales_b, compensation, M, N /*ldi*/, ldc, 1 /*ldsa*/);
457 } else
458 #elif defined(CPU_CAPABILITY_RVV)
459 if constexpr (!sym_quant_act && N == BLOCK_N && ldb == BLOCK_N / 2) {
460 _dequant_gemm_accum_rvv<N, ldb>(C, A, scales_a, qzeros_a, B, scales_b, qzeros_b, compensation, M, K, lda, ldc);
461 return;
462 } else
463 #endif
464 {
465 for (int64_t m = 0; m < M; ++m) {
466 for (int64_t n = 0; n < N; ++n) {
467 int32_t acc = 0;
468 for (int64_t k = 0; k < K; ++k) {
469 int32_t b = load_uint4_vnni<N, ldb>(B, k, n) - qzeros_b[n];
470 if constexpr (sym_quant_act) {
471 const int8_t* A_s8 = reinterpret_cast<const int8_t*>(A);
472 acc += static_cast<int32_t>(A_s8[m * lda + k]) * b;
473 } else {
474 acc += static_cast<int32_t>(A[m * lda + k]) * b;
475 }
476 }
477 if constexpr (!sym_quant_act) {
478 acc -= qzeros_a[m] * compensation[n];
479 }
480 C[m * ldc + n] += static_cast<float>(acc) * scales_a[m] * scales_b[n];
481 }
482 }
483 }
484 }
485
486 template <int64_t N>
487 inline void copy_bias(const float* bias_ptr, float* y_buf, int64_t m) {
488 if (bias_ptr) {
489 for (int i = 0; i < m; ++i) {
490 int j = 0;
491 #if defined(CPU_CAPABILITY_AVX512)
492 #pragma GCC unroll 2
493 for (; j < N; j += 16) {
494 __m512 bias_vec = _mm512_loadu_ps(bias_ptr + j);
495 _mm512_storeu_ps(y_buf + i * N + j, bias_vec);
496 }
497 #endif
498 for (; j < N; ++j) {
499 y_buf[i * N + j] = bias_ptr[j];
500 }
501 }
502 } else { // initialize to zero
503 for (int i = 0; i < m; ++i) {
504 int j = 0;
505 #if defined(CPU_CAPABILITY_AVX512)
506 #pragma GCC unroll 2
507 for (; j < N; j += 16) {
508 __m512 zero_vec = _mm512_setzero_ps();
509 _mm512_storeu_ps(y_buf + i * N + j, zero_vec);
510 }
511 #endif
512 for (; j < N; ++j) {
513 y_buf[i * N + j] = 0;
514 }
515 }
516 }
517 }
518
519 template <typename out_dtype, int64_t N>
520 inline void store_out(const float* y_buf, out_dtype* c_ptr, int64_t m, /* int64_t n, */ int64_t lda) {
521 for (int i = 0; i < m; ++i) {
522 int j = 0;
523 if constexpr (std::is_same<out_dtype, float>::value) {
524 #if defined(CPU_CAPABILITY_AVX512)
525 #pragma GCC unroll 2
526 for (; j < N; j += 16) {
527 __m512 y_vec = _mm512_loadu_ps(y_buf + i * N + j);
528 _mm512_storeu_ps(c_ptr + i * lda + j, y_vec);
529 }
530 #endif
531 for (; j < N; ++j) {
532 c_ptr[i * lda + j] = y_buf[i * N + j];
533 }
534 } else if constexpr (std::is_same<out_dtype, at::BFloat16>::value) {
535 #if defined(CPU_CAPABILITY_AVX512)
536 #pragma GCC unroll 2
537 for (; j < N; j += 16) {
538 __m512 y_vec = _mm512_loadu_ps(y_buf + i * N + j);
539 __m256i y_bf16_vec = at::vec::cvtfp32_bf16(y_vec);
540 _mm256_storeu_si256(reinterpret_cast<__m256i*>(c_ptr + i * lda + j), y_bf16_vec);
541 }
542 #endif
543 for (; j < N; ++j) {
544 c_ptr[i * lda + j] = at::BFloat16(y_buf[i * N + j]);
545 }
546 } else if constexpr (std::is_same<out_dtype, at::Half>::value) {
547 #if defined(CPU_CAPABILITY_AVX512)
548 #pragma GCC unroll 2
549 for (; j < N; j += 16) {
550 __m512 y_vec = _mm512_loadu_ps(y_buf + i * N + j);
551 __m256i y_fp16_vec = at::vec::cvtfp32_fp16(y_vec);
552 _mm256_storeu_si256(reinterpret_cast<__m256i*>(c_ptr + i * lda + j), y_fp16_vec);
553 }
554 #endif
555 for (; j < N; ++j) {
556 c_ptr[i * lda + j] = at::Half(y_buf[i * N + j]);
557 }
558 } else {
559 TORCH_CHECK(false, "Unsupported output dtype");
560 }
561 }
562 }
563
564 void fill_val_stub(int32_t* __restrict__ output, int32_t value, int64_t size) {
565 using iVec = at::vec::Vectorized<int32_t>;
566 constexpr int VecSize = iVec::size();
567 const iVec fill_val_vec = iVec(value);
568 int64_t d;
569 #pragma GCC unroll 4
570 for (d = 0; d <= size - VecSize; d += VecSize) {
571 fill_val_vec.store(output + d);
572 }
573 for (; d < size; ++d) {
574 output[d] = value;
575 }
576 }
577
578 template <typename act_dtype, typename out_dtype, bool sym_quant_act>
579 void _da8w4_linear_impl(
580 act_dtype* __restrict__ input,
581 const float* __restrict__ input_scales,
582 const int32_t* __restrict__ input_qzeros,
583 const uint8_t* __restrict__ weight,
584 const float* __restrict__ weight_scales,
585 const int8_t* __restrict__ weight_qzeros,
586 const float* __restrict__ bias,
587 out_dtype* __restrict__ output,
588 float* __restrict__ output_temp,
589 int8_t* __restrict__ dequant_weight_temp,
590 int64_t M,
591 int64_t N,
592 int64_t K,
593 int64_t num_groups) {
594 // weight + compensation shape = [Nc, Kc, BLOCK_N * _block_k / 2 + BLOCK_N*sizeof(int32_t)]
595 // scales/qzeros shape = [Nc, G, BLOCK_N]
596 const bool use_brgemm = can_use_brgemm<int8_t>(M);
597 int64_t block_m = [&]() -> long {
598 if (M <= 48) {
599 return M;
600 } else if (M < 64) {
601 return 32;
602 } else if (M < 96) {
603 return 64;
604 } else {
605 return 128;
606 }
607 }();
608 int64_t Mc = div_up(M, block_m);
609 bool parallel_on_M = M > 128;
610 int64_t Nc = N / BLOCK_N;
611 int64_t num_blocks = parallel_on_M ? Mc * Nc : Nc;
612 int64_t group_size = div_up(K, num_groups);
613 int64_t _block_k = get_4bit_block_k_size(group_size);
614 int64_t Kc = K / _block_k;
615 int64_t block_per_group = group_size / _block_k;
616
617 at::parallel_for(0, num_blocks, 1, [&](int64_t begin, int64_t end) {
618 int tid = get_thread_num();
619 float* C_tmp = output_temp + tid * block_m * BLOCK_N;
620 int8_t* dqB_tmp = dequant_weight_temp + tid * _block_k * BLOCK_N;
621 for (const auto i : c10::irange(begin, end)) {
622 int64_t mc = parallel_on_M ? i / Nc : 0;
623 int64_t nc = parallel_on_M ? i % Nc : i;
624 int64_t mc_end = parallel_on_M ? mc + 1 : Mc;
625
626 for (int mci = mc; mci < mc_end; ++mci) {
627 int64_t m_size = mci * block_m + block_m > M ? M - mci * block_m : block_m;
628 // copy bias to y_buf if bias is not None
629 auto bias_data = bias ? bias + nc * BLOCK_N : nullptr;
630 copy_bias<BLOCK_N>(bias_data, C_tmp, m_size);
631 for (int kci = 0; kci < Kc; ++kci) {
632 int32_t* compensation_ptr =
633 sym_quant_act
634 ? nullptr
635 : (int32_t*)(void*)(weight + (nc * Kc + kci) * (BLOCK_N * (_block_k / 2 + sizeof(int32_t))) +
636 _block_k * BLOCK_N / 2) /*Bcomp*/;
637 _dequant_gemm_accum<BLOCK_N, BLOCK_N / 2, sym_quant_act>(
638 /*C*/ C_tmp,
639 /*A*/ (uint8_t*)input + mci * block_m * K + kci * _block_k,
640 /*scales_a*/ input_scales + mci * block_m,
641 /*qzeros_a*/ input_qzeros + mci * block_m,
642 /*B*/ weight + (nc * Kc + kci) * (BLOCK_N * (_block_k / 2 + sizeof(int32_t))),
643 /*scales_b*/ weight_scales + nc * BLOCK_N * num_groups + kci / block_per_group * BLOCK_N,
644 /*qzeros_b*/ weight_qzeros + nc * BLOCK_N * num_groups + kci / block_per_group * BLOCK_N,
645 /*Bcomp*/ compensation_ptr,
646 /*dqB_tmp*/ dqB_tmp,
647 /*M*/ m_size,
648 /*K*/ _block_k,
649 /*lda*/ K,
650 /*ldc*/ BLOCK_N,
651 /*use_brgemm*/ use_brgemm);
652 }
653 // store y_buf to output with dtype conversion
654 store_out<out_dtype, BLOCK_N>(C_tmp, output + mci * block_m * N + nc * BLOCK_N, m_size, N /*lda*/);
655 }
656 }
657 #if defined(CPU_CAPABILITY_AVX512)
658 if (use_brgemm) {
659 at::native::cpublas::brgemm_release();
660 }
661 #endif
662 });
663 }
664
665 } // anonymous namespace
666
667 /*
668 return: packed_weight, packed_scales, packed_qzeros
669 */
670 std::tuple<at::Tensor, at::Tensor, at::Tensor> convert_int4_weight_packed_with_compensation(
671 const at::Tensor& weight, const at::Tensor& scales, const at::Tensor& qzeros) {
672 // weight shape = [N, K]
673 // scales shape = [N, G]
674 // qzeros shape = [N, G]
675 TORCH_CHECK(weight.dim() == 2, "DA8W4 CPU: Weight should be a 2D tensor for packing");
676 TORCH_CHECK(weight.size(1) % 2 == 0, "DA8W4 CPU: Weight should have even number of columns for packing");
677
678 auto new_scales = scales;
679 auto new_qzeros = qzeros;
680 if (new_scales.dim() == 1) {
681 new_scales.unsqueeze_(1);
682 }
683 new_scales = new_scales.to(at::kFloat);
684 if (new_qzeros.dim() == 1) {
685 new_qzeros.unsqueeze_(1);
686 }
687 new_qzeros = new_qzeros.to(at::kChar);
688 int64_t N = weight.size(0);
689 int64_t K = weight.size(1);
690 int64_t G = scales.size(1);
691 int64_t group_size = K / G;
692 int64_t _block_k = get_4bit_block_k_size(group_size);
693 constexpr int block_n = block_size_n();
694 int64_t Nc = N / block_n;
695 int64_t Kc = K / _block_k;
696
697 // Reorder weight to [N/block_n, K/_block_k, _block_k, block_n]
698 // Reorder scales/qzeros to [N/block_n, G, block_n]
699 // weight + compensation shape = [Nc, Kc, block_n * _block_k / 2 + block_n*sizeof(int32_t)]
700 // scales/qzeros shape = [Nc, G, block_n]
701 auto weight_view = weight.view({Nc, block_n, Kc, _block_k});
702 at::Tensor weight_reordered = weight_view.permute({0, 2, 3, 1}).contiguous();
703 at::Tensor blocked_weight;
704 at::Tensor blocked_scales = new_scales.view({Nc, block_n, G}).permute({0, 2, 1}).contiguous();
705 at::Tensor blocked_qzeros = new_qzeros.view({Nc, block_n, G}).permute({0, 2, 1}).contiguous();
706 // Compensation = Σ(k)(W[k][n] - ZP[n]) for each block.
707 auto weight_sub_qzero = weight.view({Nc, block_n, G, -1}).to(at::kInt) - new_qzeros.view({Nc, block_n, G, -1});
708 weight_sub_qzero = weight_sub_qzero.view({Nc, block_n, Kc, _block_k});
709 at::Tensor compensation = weight_sub_qzero.sum(-1);
710 compensation = compensation.permute({0, 2, 1}).contiguous().to(at::kInt);
711 int64_t buffer_size_nbytes = _block_k * block_n / 2 + block_n * sizeof(int32_t);
712 blocked_weight = at::empty({Nc, Kc, buffer_size_nbytes}, weight.options());
713
714 auto weight_ptr = weight_reordered.data_ptr<uint8_t>();
715 auto compensation_ptr = compensation.data_ptr<int32_t>();
716 auto blocked_weight_ptr = blocked_weight.data_ptr<uint8_t>();
717 int64_t num_blocks = Nc * Kc;
718 at::parallel_for(0, num_blocks, 1, [&](int64_t begin, int64_t end) {
719 for (const auto i : c10::irange(begin, end)) {
720 auto in_ptr = weight_ptr + i * _block_k * block_n;
721 auto out_ptr = blocked_weight_ptr + i * block_n * (_block_k / 2 + sizeof(int32_t));
722 int32_t* comp_in_prt = compensation_ptr + i * block_n;
723 int32_t* comp_out_prt = (int32_t*)(void*)(blocked_weight_ptr + i * block_n * (_block_k / 2 + sizeof(int32_t)) +
724 _block_k * block_n / 2);
725 // Reorder weight block to VNNI4 and pack two lanes along N
726 // N=16 viewed as two lanes: a0, ...a7, b0, ...b7
727 // pack two lanes: [a0, b0], ..., [a7, b7]
728 // plain shape = [_block_k, block_n]
729 // packed shape = [_block_k / 4, block_n / 2, 4] viewed as [_block_k, block_n / 2]
730 constexpr int n_group_size = 8;
731 constexpr int vnni_size = 4;
732 constexpr int n_group = block_n / n_group_size; // 4
733 for (int nb = 0; nb < n_group; nb += 2) {
734 for (int k = 0; k < _block_k; k += vnni_size) {
735 for (int ni = 0; ni < n_group_size; ++ni) {
736 for (int ki = 0; ki < vnni_size; ++ki) {
737 int src_idx_1 = nb * n_group_size + ni + (k + ki) * block_n;
738 int src_idx_2 = (nb + 1) * n_group_size + ni + (k + ki) * block_n;
739 int dst_idx = (nb / 2 * n_group_size + ni) * vnni_size + k * block_n / 2 + ki;
740 uint8_t src_1 = *(in_ptr + src_idx_1);
741 uint8_t src_2 = *(in_ptr + src_idx_2);
742 uint8_t dst = (src_1 & 0x0f) | ((src_2 & 0x0f) << 4);
743 *(out_ptr + dst_idx) = dst;
744 }
745 }
746 }
747 }
748 // compensation [block_n]
749 for (int nb = 0; nb < block_n; nb++) {
750 *(comp_out_prt + nb) = *(comp_in_prt + nb);
751 }
752 }
753 });
754
755 return std::make_tuple(std::move(blocked_weight), std::move(blocked_scales), std::move(blocked_qzeros));
756 }
757
758 std::tuple<at::Tensor, at::Tensor> unpack_4bit_to_32bit_signed(const at::Tensor& qweight, const at::Tensor& qzeros) {
759 TORCH_CHECK(qweight.scalar_type() == at::kInt, "qweight must be int32");
760 TORCH_CHECK(qzeros.scalar_type() == at::kInt, "qzeros must be int32");
761 const auto W0 = qweight.size(0);
762 const auto W1 = qweight.size(1);
763 const auto Z0 = qzeros.size(0);
764 const auto Z1 = qzeros.size(1);
765
766 // unpacked_weights: (W0 * 8, W1), int8
767 auto unpacked_weights = at::zeros({W0 * 8, W1}, at::TensorOptions().dtype(at::kChar));
768 // unpacked_zeros: (Z0, Z1 * 8), int8
769 auto unpacked_zeros = at::zeros({Z0, Z1 * 8}, at::TensorOptions().dtype(at::kChar));
770
771 const int32_t* qw_ptr = qweight.data_ptr<int32_t>();
772 const int32_t* qz_ptr = qzeros.data_ptr<int32_t>();
773 int8_t* uw_ptr = unpacked_weights.data_ptr<int8_t>();
774 int8_t* uz_ptr = unpacked_zeros.data_ptr<int8_t>();
775
776 // ---- unpack qweight ----
777 for (int64_t row = 0; row < W0 * 8; ++row) {
778 const int i = row & 7; // row % 8
779 const int src_row = row >> 3; // row // 8
780 const int shift = 4 * i;
781 for (int64_t col = 0; col < W1; ++col) {
782 int32_t v = qw_ptr[src_row * W1 + col];
783 uw_ptr[row * W1 + col] = static_cast<int8_t>((v >> shift) & 0xF);
784 }
785 }
786 // ---- unpack qzeros ----
787 for (int64_t col = 0; col < Z1 * 8; ++col) {
788 const int i = col & 7;
789 const int src_col = col >> 3;
790 const int shift = 4 * i;
791
792 for (int64_t row = 0; row < Z0; ++row) {
793 int32_t v = qz_ptr[row * Z1 + src_col];
794 uz_ptr[row * (Z1 * 8) + col] = static_cast<int8_t>((v >> shift) & 0xF);
795 }
796 }
797
798 return std::make_tuple(unpacked_weights, unpacked_zeros + 1);
799 }
800
801 std::tuple<at::Tensor, at::Tensor>
802 autogptq_to_int4pack(const at::Tensor& qweight_tensor, const at::Tensor& qzeros_tensor) {
803 TORCH_CHECK(qweight_tensor.scalar_type() == at::kInt, "qweight_tensor must be int32");
804 TORCH_CHECK(qzeros_tensor.scalar_type() == at::kInt, "qzeros_tensor must be int32");
805 TORCH_CHECK(qweight_tensor.is_cpu(), "CPU only implementation");
806 if (qweight_tensor.dim() == 3) {
807 const int64_t B = qweight_tensor.size(0);
808 std::vector<at::Tensor> qweight_list;
809 std::vector<at::Tensor> qzeros_list;
810 qweight_list.reserve(B);
811 qzeros_list.reserve(B);
812 for (int64_t i = 0; i < B; ++i) {
813 auto outputs = unpack_4bit_to_32bit_signed(qweight_tensor[i], qzeros_tensor[i]);
814 at::Tensor unpacked_qweight = std::get<0>(outputs);
815 at::Tensor unpacked_qzeros = std::get<1>(outputs);
816 qweight_list.push_back(unpacked_qweight.transpose(0, 1).contiguous().to(at::kByte));
817 qzeros_list.push_back(unpacked_qzeros.contiguous().to(at::kByte));
818 }
819 return std::make_tuple(at::stack(qweight_list).detach(), at::stack(qzeros_list).detach());
820 }
821 auto outputs = unpack_4bit_to_32bit_signed(qweight_tensor, qzeros_tensor);
822 at::Tensor unpacked_qweight = std::get<0>(outputs);
823 at::Tensor unpacked_qzeros = std::get<1>(outputs);
824 at::Tensor return_qweight = unpacked_qweight.transpose(0, 1).contiguous().to(at::kByte);
825 at::Tensor return_qzeros = unpacked_qzeros.contiguous().to(at::kByte);
826 return std::make_tuple(return_qweight, return_qzeros);
827 }
828
829 std::tuple<at::Tensor, at::Tensor> int4pack(at::Tensor qweight, at::Tensor qzeros, int64_t quant_method_4bit) {
830 if (quant_method_4bit == CPUQuantAlgo::AWQ) {
831 // autoawq unpacking
832 qweight = qweight.contiguous();
833 qzeros = qzeros.contiguous();
834 // bitshifts: [0, 4, 1, 5, 2, 6, 3, 7] * 4
835 auto bitshifts = at::tensor({0, 4, 1, 5, 2, 6, 3, 7}, at::kInt) * 4;
836 auto qweight_unsq = qweight.unsqueeze(-1); // [..., K, N/8, 1]
837 auto unpacked = (at::bitwise_right_shift(qweight_unsq, bitshifts) & 0xF).contiguous();
838 auto qweight_final = unpacked.flatten(-2).transpose(-1, -2).to(at::kByte).clone();
839 auto qzeros_unsq = qzeros.unsqueeze(-1);
840 auto qzeros_unpacked = (at::bitwise_right_shift(qzeros_unsq, bitshifts) & 0xF).contiguous();
841 auto qzeros_final = qzeros_unpacked.flatten(-2).to(at::kByte).clone();
842 return std::make_tuple(qweight_final, qzeros_final);
843 } else if (quant_method_4bit == CPUQuantAlgo::GPTQ) {
844 // autogptq unpacking
845 auto outputs = autogptq_to_int4pack(qweight, qzeros);
846 at::Tensor unpacked_qweight = std::get<0>(outputs);
847 at::Tensor unpacked_qzeros = std::get<1>(outputs);
848 return std::make_tuple(unpacked_qweight, unpacked_qzeros);
849 } else {
850 TORCH_CHECK(false, "CPU int4 pack only support AWQ or GPTQ...");
851 }
852 }
853
854 std::tuple<at::Tensor, at::Tensor, at::Tensor> convert_weight_packed_scale_zp(
855 at::Tensor qweight, // awq: (*, K, N / 8) || gptq: (*, K / 8, N) , int32
856 at::Tensor qzeros, // awq: (*, K / group_size, N / 8) || gptq: (*, K / group_size, N / 8) , int32
857 at::Tensor scales, // awq: (*, K / group_size, N) || gptq: (*, K / group_size, N) , bfloat16
858 int64_t quant_method_4bit) {
859 at::Tensor _qweight;
860 at::Tensor _qzeros;
861
862 auto res = int4pack(qweight, qzeros, quant_method_4bit);
863 _qweight = std::get<0>(res);
864 _qzeros = std::get<1>(res);
865
866 auto _scales = scales;
867 _qzeros = _qzeros.transpose(-2, -1).contiguous(); // .T
868 _scales = _scales.transpose(-2, -1).contiguous();
869 if (_qweight.dim() == 3) { // Dim=3 for MOE packing, TODO: refine a unified loop
870 int64_t E = _qweight.size(0);
871 int64_t K = _qweight.size(2);
872 int64_t G = _scales.size(2);
873 int64_t group_size = K / G;
874 int64_t _block_k = get_4bit_block_k_size(group_size);
875 int64_t block_n = block_size_n();
876 int64_t Nc = _qweight.size(1) / block_n;
877 int64_t Kc = K / _block_k;
878 int64_t buffer_size_nbytes = _block_k * block_n / 2 + block_n * sizeof(int32_t);
879 auto blocked_weight = at::empty({E, Nc, Kc, buffer_size_nbytes}, _qweight.options());
880 auto blocked_scales = at::empty({E, Nc, G, block_n}, _scales.options()).to(at::kFloat);
881 auto blocked_qzeros = at::empty({E, Nc, G, block_n}, _qzeros.options()).to(at::kChar);
882 for (int i = 0; i < _qweight.size(0); i++) {
883 auto res_ = convert_int4_weight_packed_with_compensation(_qweight[i], _scales[i], _qzeros[i]);
884 blocked_weight[i] = std::get<0>(res_);
885 blocked_scales[i] = std::get<1>(res_);
886 blocked_qzeros[i] = std::get<2>(res_);
887 }
888 _qweight = blocked_weight;
889 _scales = blocked_scales;
890 _qzeros = blocked_qzeros;
891 } else {
892 auto res_ = convert_int4_weight_packed_with_compensation(_qweight, _scales, _qzeros);
893 _qweight = std::get<0>(res_);
894 _scales = std::get<1>(res_);
895 _qzeros = std::get<2>(res_);
896 }
897
898 return std::make_tuple(_qweight, _qzeros, _scales);
899 }
900
901 at::Tensor int4_scaled_mm_cpu_with_quant(
902 const at::Tensor& input,
903 const at::Tensor& weight,
904 const at::Tensor& weight_scales,
905 const at::Tensor& weight_qzeros,
906 const std::optional<at::Tensor>& bias,
907 at::ScalarType output_dtype) {
908 int64_t M_a = input.size(0);
909 int64_t K_a = input.size(1);
910 int64_t lda = input.stride(0);
911
912 const auto st = input.scalar_type();
913 TORCH_CHECK(
914 st == at::kBFloat16 || st == at::kHalf, "int4_scaled_mm_cpu_with_quant: expect A to be bfloat16 or half.");
915
916 constexpr bool sym_quant_act = false; // TODO: add sym quant path
917 using Tin = typename ActDtype<sym_quant_act>::type;
918 int64_t act_buffer_size = /* act quant */ M_a * K_a +
919 /* act scale */ M_a * sizeof(float) +
920 /* act zp */ M_a * sizeof(int32_t);
921 auto act_buffer = at::empty({act_buffer_size}, input.options().dtype(at::kByte));
922 // asym path, activation quants into uint8_t
923 auto Aq_data = act_buffer.data_ptr<uint8_t>();
924 auto As_data = reinterpret_cast<float*>(Aq_data + M_a * K_a);
925 auto Azp_data = reinterpret_cast<int32_t*>(As_data + M_a);
926 fill_val_stub(Azp_data, 128, M_a); // sym_a s8s8 is unified to u8s8 with compensation (128)
927
928 auto out_sizes = input.sizes().vec();
929 int64_t N = weight_scales.size(0) * weight_scales.size(-1);
930 out_sizes.back() = N;
931 auto output = at::empty(out_sizes, input.options());
932 // weight + compensation shape = [Nc, Kc, BLOCK_N * _block_k / 2 + BLOCK_N*sizeof(int32_t)]
933 // scales/qzeros shape = [Nc, G, BLOCK_N]
934 int64_t Nc = weight.size(0);
935 int64_t Kc = weight.size(1);
936 int64_t _block_k = K_a / Kc;
937 TORCH_CHECK(N == Nc * BLOCK_N, "DA8W4: weight and input shapes mismatch");
938 // scales/qzeros shape = [Nc, G, BLOCK_N]
939 int64_t num_groups = weight_scales.size(1);
940
941 const uint8_t* b_ptr = weight.data_ptr<uint8_t>();
942 const float* b_scales_ptr = weight_scales.data_ptr<float>();
943 const int8_t* b_qzeros_ptr = weight_qzeros.data_ptr<int8_t>();
944 const float* bias_ptr = bias.has_value() ? bias.value().data_ptr<float>() : nullptr;
945 int num_threads = at::get_num_threads();
946 int64_t temp_buffer_size = /* output temp */ num_threads * BLOCK_M * BLOCK_N * sizeof(float) +
947 /* weight dequant temp */ num_threads * _block_k * BLOCK_N;
948 auto c_temp_buffer = at::empty({temp_buffer_size}, input.options().dtype(at::kChar));
949 float* c_temp_ptr = (float*)((void*)(c_temp_buffer.data_ptr<int8_t>()));
950 int8_t* dqB_temp_ptr = (int8_t*)((void*)(c_temp_ptr + num_threads * BLOCK_M * BLOCK_N));
951
952 #define LAUNCH_DA8W4_LINEAR_WITH_QUANT_IMPL(sym_quant_act) \
953 AT_DISPATCH_FLOATING_TYPES_AND2( \
954 at::ScalarType::BFloat16, at::ScalarType::Half, output_dtype, "int4_scaled_mm_cpu_with_quant", [&] { \
955 const scalar_t* __restrict__ A_data = input.data_ptr<scalar_t>(); \
956 scalar_t* __restrict__ c_ptr = output.data_ptr<scalar_t>(); \
957 at::parallel_for(0, M_a, 0, [&](int64_t begin, int64_t end) { \
958 for (int64_t m = begin; m < end; ++m) { \
959 quantize_row_int8<scalar_t>(Aq_data + m * K_a, As_data[m], A_data + m * lda, K_a); \
960 } \
961 }); \
962 _da8w4_linear_impl<Tin, scalar_t, sym_quant_act>( \
963 Aq_data, \
964 As_data, \
965 Azp_data, \
966 b_ptr, \
967 b_scales_ptr, \
968 b_qzeros_ptr, \
969 bias_ptr, \
970 c_ptr, \
971 c_temp_ptr, \
972 dqB_temp_ptr, \
973 M_a, \
974 N, \
975 K_a, \
976 num_groups); \
977 });
978
979 LAUNCH_DA8W4_LINEAR_WITH_QUANT_IMPL(sym_quant_act);
980
981 return output;
982 }
983 template <typename scalar_t>
984 inline void copy_stub(scalar_t* __restrict__ out, const float* __restrict__ input, int64_t size) {
985 using Vec = at::vec::Vectorized<scalar_t>;
986 using fVec = at::vec::Vectorized<float>;
987 // no remainder
988 #pragma GCC unroll 4
989 for (int64_t d = 0; d < size; d += Vec::size()) {
990 fVec x0 = fVec::loadu(input + d);
991 fVec x1 = fVec::loadu(input + d + fVec::size());
992 Vec res = convert_from_float_ext<scalar_t>(x0, x1);
993 res.store(out + d);
994 }
995 }
996
997 template <typename scalar_t>
998 void tinygemm_kernel(
999 scalar_t* C,
1000 float* C_temp,
1001 const uint8_t* A,
1002 const float* scales_a,
1003 const int32_t* qzeros_a,
1004 const uint8_t* B,
1005 const float* scales_b,
1006 const int8_t* qzeros_b,
1007 const int32_t* compensation,
1008 int8_t* dqB_tmp,
1009 int64_t M,
1010 int64_t K,
1011 int64_t lda,
1012 int64_t ldc_f,
1013 int64_t ldc_s,
1014 bool store_out,
1015 bool use_brgemm) {
1016 // TODO: add sym quant act, now only asym
1017 _dequant_gemm_accum<BLOCK_N, BLOCK_N / 2, false>(
1018 C_temp, A, scales_a, qzeros_a, B, scales_b, qzeros_b, compensation, dqB_tmp, M, K, lda, ldc_f, use_brgemm);
1019 if (store_out) {
1020 // copy from Ctmp to C
1021 for (int64_t m = 0; m < M; ++m) {
1022 copy_stub<scalar_t>(C + m * ldc_s, C_temp + m * ldc_f, BLOCK_N);
1023 }
1024 }
1025 }
1026
1027 #define INSTANTIATE_TINYGEMM_TEMPLATE(TYPE) \
1028 template void tinygemm_kernel<TYPE>( \
1029 TYPE * C, \
1030 float* C_temp, \
1031 const uint8_t* A, \
1032 const float* scales_a, \
1033 const int32_t* qzeros_a, \
1034 const uint8_t* B, \
1035 const float* scales_b, \
1036 const int8_t* qzeros_b, \
1037 const int32_t* compensation, \
1038 int8_t* dqB_tmp, \
1039 int64_t M, \
1040 int64_t K, \
1041 int64_t lda, \
1042 int64_t ldc_f, \
1043 int64_t ldc_s, \
1044 bool store_out, \
1045 bool use_brgemm)
1046
1047 INSTANTIATE_TINYGEMM_TEMPLATE(at::BFloat16);
1048 INSTANTIATE_TINYGEMM_TEMPLATE(at::Half);
1049
1050 // int4 gemm dispatch api register
1051 at::Tensor int4_scaled_mm_cpu(
1052 at::Tensor& x, at::Tensor& w, at::Tensor& w_zeros, at::Tensor& w_scales, std::optional<at::Tensor> bias) {
1053 return int4_scaled_mm_cpu_with_quant(x, w, w_scales, w_zeros, bias, x.scalar_type());
1054 }