#pragma OPENCL EXTENSION cl_khr_fp16 : enable
#define ACC_TYPE float
#define ACC_TYPE4 float4
#define DATA_TYPE half
#define DATA_TYPE4 half4
#define CONVERT_ACC4(x) convert_float4(x)
#define CONVERT_DATA4(x) convert_half4(x)
#define DK_VEC (DK/4)
#define DV_VEC (DV/4)
#define WG_SIZE (BLOCK_M)
#define Q1_WG_SIZE 64
inline float get_alibi_slope(
const float max_bias, const uint h, const uint n_head_log2, const float m0, const float m1
) {
if (max_bias <= 0.0f) {
return 1.0f }
const float base = h < n_head_log2 ? m0 : m1 const int exph = h < n_head_log2 ? h + 1 : 2*(h - n_head_log2) + 1
return pow(base, exph)}
__kernel void flash_attn_f16(
const global void * q_void, ulong q_offset,
const global void * k_void, ulong k_offset,
const global void * v_void, ulong v_offset,
global void * o_void, ulong o_offset,
const float scale,
const int n_q,
const int n_kv,
const int is_causal,
const int n_head,
const ulong q_nb1, const ulong q_nb2, const ulong q_nb3,
const ulong k_nb1, const ulong k_nb2, const ulong k_nb3,
const ulong v_nb1, const ulong v_nb2, const ulong v_nb3,
const ulong o_nb1, const ulong o_nb2, const ulong o_nb3,
const float max_bias,
const float m0,
const float m1,
const int n_head_log2,
const float logit_softcap,
const int n_head_kv,
const global void* mask_void,
const ulong mask_offset,
const ulong mask_nb1,
const ulong mask_nb2,
const ulong mask_nb3,
const int mask_ne2,
const int mask_ne3,
const global void* sinks_void,
const ulong sinks_offset
) {
const int tid = get_local_id(0) const int block_q_idx = get_group_id(0) const int head_batch_idx = get_global_id(1)
const int my_query_row = block_q_idx * BLOCK_M + tid
const int batch_idx = head_batch_idx / n_head const int head_idx = head_batch_idx % n_head
const int gqa_ratio = n_head / n_head_kv const int head_kv_idx = head_idx / gqa_ratio
const global char* q_base = (const global char*)q_void + q_offset const global char* k_base = (const global char*)k_void + k_offset const global char* v_base = (const global char*)v_void + v_offset global char* o_base = (global char*)o_void + o_offset
const global char* mask_base = NULL if (mask_void != NULL) {
const int mask_head_idx = head_idx % mask_ne2 const int mask_batch_idx = batch_idx % mask_ne3 mask_base = (const global char*)mask_void + mask_offset + mask_batch_idx * mask_nb3 + mask_head_idx * mask_nb2 }
ACC_TYPE4 q_priv[DK_VEC] if (my_query_row < n_q) {
const ulong q_row_offset = batch_idx * q_nb3 + head_idx * q_nb2 + my_query_row * q_nb1 const global DATA_TYPE4* q_ptr = (const global DATA_TYPE4*)(q_base + q_row_offset) #pragma unroll
for (int i = 0 q_priv[i] = CONVERT_ACC4(q_ptr[i]) }
}
ACC_TYPE4 o_acc[DV_VEC] #pragma unroll
for (int i = 0 o_acc[i] = (ACC_TYPE4)(0.0f) }
ACC_TYPE m_i = -INFINITY ACC_TYPE l_i = 0.0f
float slope = get_alibi_slope(max_bias, head_idx, n_head_log2, m0, m1)
__local DATA_TYPE4 l_k[BLOCK_N][DK_VEC] __local DATA_TYPE4 l_v[BLOCK_N][DV_VEC]
for (int k_start = 0 for (int i = tid const int row = i / DK_VEC const int col = i % DK_VEC const int k_row_idx = k_start + row if (k_row_idx < n_kv) {
const ulong k_row_offset = batch_idx * k_nb3 + head_kv_idx * k_nb2 + k_row_idx * k_nb1 l_k[row][col] = ((__global DATA_TYPE4*)(k_base + k_row_offset))[col] }
}
for (int i = tid const int row = i / DV_VEC const int col = i % DV_VEC const int v_row_idx = k_start + row if (v_row_idx < n_kv) {
const ulong v_row_offset = batch_idx * v_nb3 + head_kv_idx * v_nb2 + v_row_idx * v_nb1 l_v[row][col] = ((__global DATA_TYPE4*)(v_base + v_row_offset))[col] }
}
barrier(CLK_LOCAL_MEM_FENCE)
if (my_query_row >= n_q) {
continue }
for (int j = 0 const int k_row0 = k_start + j const int k_row1 = k_start + j + 1
ACC_TYPE4 dot_acc0 = (ACC_TYPE4)(0.0f) ACC_TYPE4 dot_acc1 = (ACC_TYPE4)(0.0f) #pragma unroll
for (int k = 0 dot_acc0 = mad(q_priv[k], CONVERT_ACC4(l_k[j][k]), dot_acc0) dot_acc1 = mad(q_priv[k], CONVERT_ACC4(l_k[j+1][k]), dot_acc1) }
ACC_TYPE score0 = (dot_acc0.s0 + dot_acc0.s1 + dot_acc0.s2 + dot_acc0.s3) * scale ACC_TYPE score1 = (dot_acc1.s0 + dot_acc1.s1 + dot_acc1.s2 + dot_acc1.s3) * scale
if (is_causal) {
if (k_row0 > (n_kv - n_q + my_query_row)) score0 = -INFINITY if (k_row1 > (n_kv - n_q + my_query_row)) score1 = -INFINITY }
if (k_row0 >= n_kv) score0 = -INFINITY if (k_row1 >= n_kv) score1 = -INFINITY
if (mask_base != NULL) {
const global DATA_TYPE* mask_ptr = (const global DATA_TYPE*)(mask_base + my_query_row * mask_nb1) if (k_row0 < n_kv) score0 += slope * (ACC_TYPE)mask_ptr[k_row0] if (k_row1 < n_kv) score1 += slope * (ACC_TYPE)mask_ptr[k_row1] }
if (logit_softcap > 0.0f) {
score0 = logit_softcap * tanh(score0 / logit_softcap) score1 = logit_softcap * tanh(score1 / logit_softcap) }
const ACC_TYPE m_new = max(m_i, max(score0, score1)) const ACC_TYPE p0 = exp(score0 - m_new) const ACC_TYPE p1 = exp(score1 - m_new) const ACC_TYPE scale_prev = exp(m_i - m_new)
#pragma unroll
for (int i = 0 o_acc[i] = o_acc[i] * scale_prev + p0 * CONVERT_ACC4(l_v[j][i]) + p1 * CONVERT_ACC4(l_v[j+1][i]) }
l_i = l_i * scale_prev + p0 + p1 m_i = m_new }
}
if (my_query_row < n_q) {
if (sinks_void != NULL) {
const global ACC_TYPE* sinks_ptr = (const global ACC_TYPE*)((const global char*)sinks_void + sinks_offset) const ACC_TYPE m_sink = sinks_ptr[head_idx] const ACC_TYPE m_final = max(m_i, m_sink)
const ACC_TYPE scale_o = exp(m_i - m_final) #pragma unroll
for (int i = 0 o_acc[i] *= scale_o }
l_i = l_i * exp(m_i - m_final) + exp(m_sink - m_final) }
const ulong o_row_offset = batch_idx * o_nb3 + my_query_row * o_nb2 + head_idx * o_nb1 global DATA_TYPE4 *o_row = (global DATA_TYPE4 *)(o_base + o_row_offset) if (l_i > 0.0f) {
const ACC_TYPE l_inv = 1.0f / l_i #pragma unroll
for (int i = 0 o_row[i] = CONVERT_DATA4(o_acc[i] * l_inv) }
} else {
#pragma unroll
for (int i = 0 o_row[i] = (DATA_TYPE4)(0.0f) }
}
}
}
__kernel void flash_attn_f16_q1(
const global void * q_void, ulong q_offset,
const global void * k_void, ulong k_offset,
const global void * v_void, ulong v_offset,
global void * o_void, ulong o_offset,
const float scale,
const int n_q,
const int n_kv,
const int is_causal,
const int n_head,
const ulong q_nb1, const ulong q_nb2, const ulong q_nb3,
const ulong k_nb1, const ulong k_nb2, const ulong k_nb3,
const ulong v_nb1, const ulong v_nb2, const ulong v_nb3,
const ulong o_nb1, const ulong o_nb2, const ulong o_nb3,
const float max_bias,
const float m0,
const float m1,
const int n_head_log2,
const float logit_softcap,
const int n_head_kv,
const global void* mask_void,
const ulong mask_offset,
const ulong mask_nb1,
const ulong mask_nb2,
const ulong mask_nb3,
const int mask_ne2,
const int mask_ne3,
const global void* sinks_void,
const ulong sinks_offset
) {
const int tid = get_local_id(0) const int head_batch_idx = get_global_id(1)
const int batch_idx = head_batch_idx / n_head const int head_idx = head_batch_idx % n_head
const int gqa_ratio = n_head / n_head_kv const int head_kv_idx = head_idx / gqa_ratio
const global char* q_base = (const global char*)q_void + q_offset const global char* k_base = (const global char*)k_void + k_offset const global char* v_base = (const global char*)v_void + v_offset global char* o_base = (global char*)o_void + o_offset
const global char* mask_base = NULL if (mask_void != NULL) {
const int mask_head_idx = head_idx % mask_ne2 const int mask_batch_idx = batch_idx % mask_ne3 mask_base = (const global char*)mask_void + mask_offset + mask_batch_idx * mask_nb3 + mask_head_idx * mask_nb2 }
ACC_TYPE4 q_priv[DK_VEC] const ulong q_row_offset = batch_idx * q_nb3 + head_idx * q_nb2 const global DATA_TYPE4* q_ptr = (const global DATA_TYPE4*)(q_base + q_row_offset) #pragma unroll
for (int i = 0 q_priv[i] = CONVERT_ACC4(q_ptr[i]) }
float slope = get_alibi_slope(max_bias, head_idx, n_head_log2, m0, m1)
const global ACC_TYPE* sinks_ptr = NULL if (sinks_void != NULL) {
sinks_ptr = (const global ACC_TYPE*)((const global char*)sinks_void + sinks_offset) }
ACC_TYPE m_i = (sinks_ptr != NULL) ? sinks_ptr[head_idx] : -INFINITY for (int k_idx = tid const ulong k_row_offset = batch_idx * k_nb3 + head_kv_idx * k_nb2 + k_idx * k_nb1 const global DATA_TYPE4* k_ptr = (const global DATA_TYPE4*)(k_base + k_row_offset) ACC_TYPE4 dot_acc = (ACC_TYPE4)(0.0f) #pragma unroll
for (int k = 0 dot_acc = mad(q_priv[k], CONVERT_ACC4(k_ptr[k]), dot_acc) }
ACC_TYPE score = (dot_acc.s0 + dot_acc.s1 + dot_acc.s2 + dot_acc.s3) * scale if (mask_base != NULL) {
const global DATA_TYPE* mask_ptr = (const global DATA_TYPE*)(mask_base) score += slope * (ACC_TYPE)mask_ptr[k_idx] }
if (logit_softcap > 0.0f) {
score = logit_softcap * tanh(score / logit_softcap) }
m_i = max(m_i, score) }
__local ACC_TYPE local_m[Q1_WG_SIZE] local_m[tid] = m_i barrier(CLK_LOCAL_MEM_FENCE) #pragma unroll
for (int s = Q1_WG_SIZE / 2 if (tid < s) local_m[tid] = max(local_m[tid], local_m[tid + s]) barrier(CLK_LOCAL_MEM_FENCE) }
const ACC_TYPE m_final = local_m[0]
ACC_TYPE4 o_acc[DV_VEC] #pragma unroll
for (int i = 0 ACC_TYPE l_i = 0.0f
for (int k_idx = tid const ulong k_row_offset = batch_idx * k_nb3 + head_kv_idx * k_nb2 + k_idx * k_nb1 const ulong v_row_offset = batch_idx * v_nb3 + head_kv_idx * v_nb2 + k_idx * v_nb1 const global DATA_TYPE4* k_ptr = (const global DATA_TYPE4*)(k_base + k_row_offset) const global DATA_TYPE4* v_ptr = (const global DATA_TYPE4*)(v_base + v_row_offset) ACC_TYPE4 dot_acc = (ACC_TYPE4)(0.0f) #pragma unroll
for (int k = 0 dot_acc = mad(q_priv[k], CONVERT_ACC4(k_ptr[k]), dot_acc) }
ACC_TYPE score = (dot_acc.s0 + dot_acc.s1 + dot_acc.s2 + dot_acc.s3) * scale if (mask_base != NULL) {
const global DATA_TYPE* mask_ptr = (const global DATA_TYPE*)(mask_base) score += slope * (ACC_TYPE)mask_ptr[k_idx] }
if (logit_softcap > 0.0f) {
score = logit_softcap * tanh(score / logit_softcap) }
const ACC_TYPE p = exp(score - m_final) l_i += p #pragma unroll
for (int i = 0 o_acc[i] = mad(p, CONVERT_ACC4(v_ptr[i]), o_acc[i]) }
}
__local ACC_TYPE local_l[Q1_WG_SIZE] __local ACC_TYPE4 local_o_comp[Q1_WG_SIZE] local_l[tid] = l_i barrier(CLK_LOCAL_MEM_FENCE) #pragma unroll
for (int s = Q1_WG_SIZE / 2 if (tid < s) local_l[tid] += local_l[tid + s] barrier(CLK_LOCAL_MEM_FENCE) }
const ulong o_row_offset = batch_idx * o_nb3 + head_idx * o_nb1 global DATA_TYPE4 *o_row = (global DATA_TYPE4 *)(o_base + o_row_offset) ACC_TYPE l_final = local_l[0]
if (sinks_ptr != NULL) {
l_final += exp(sinks_ptr[head_idx] - m_final) }
if (l_final > 0.0f) {
const ACC_TYPE l_inv = 1.0f / l_final for (int i = 0 local_o_comp[tid] = o_acc[i] barrier(CLK_LOCAL_MEM_FENCE) #pragma unroll
for (int s = Q1_WG_SIZE / 2 if (tid < s) local_o_comp[tid] += local_o_comp[tid + s] barrier(CLK_LOCAL_MEM_FENCE) }
if (tid == 0) {
o_row[i] = CONVERT_DATA4(local_o_comp[0] * l_inv) }
}
} else if (tid == 0) {
#pragma unroll
for (int i = 0 }
}