#version 450
#extension GL_EXT_control_flow_attributes : require
#define BLOCK_SIZE 64
layout(local_size_x = BLOCK_SIZE, local_size_y = 1, local_size_z = 1) in;
layout(push_constant) uniform Parameters {
uint B;
uint T;
uint C;
uint H;
float scale;
};
layout(binding = 0) readonly buffer KBuf { A_TYPE k[]; };
layout(binding = 1) readonly buffer VBuf { A_TYPE v[]; };
layout(binding = 2) readonly buffer QBuf { A_TYPE q[]; };
layout(binding = 3) readonly buffer GBuf { A_TYPE g[]; };
layout(binding = 4) readonly buffer StateBuf { A_TYPE state_in[]; };
layout(binding = 5) buffer DstBuf { A_TYPE dst[]; };
shared A_TYPE _k[BLOCK_SIZE], _q[BLOCK_SIZE], _g[BLOCK_SIZE];
void main() {
const uint head_size = BLOCK_SIZE;
const uint batch_id = gl_WorkGroupID.x / H;
const uint head_id = gl_WorkGroupID.x % H;
const uint tid = gl_LocalInvocationID.x;
const uint state_size = C * head_size;
const uint n_seq_tokens = T / B;
if (batch_id >= B || head_id >= H) {
return;
}
// state[i] holds column tid of this head's state matrix: S[i][tid]
A_TYPE state[BLOCK_SIZE];
[[unroll]] for (uint i = 0; i < head_size; i++) {
state[i] = state_in[batch_id * state_size + head_id * head_size * head_size
+ i * head_size + tid];
}
const uint start_t = batch_id * n_seq_tokens * C + head_id * head_size + tid;
const uint end_t = (batch_id + 1) * n_seq_tokens * C + head_id * head_size + tid;
for (uint t = start_t; t < end_t; t += C) {
barrier();
_k[tid] = k[t];
_q[tid] = q[t];
_g[tid] = g[t];
barrier();
const A_TYPE v_val = v[t];
A_TYPE y = 0.0;
[[unroll]] for (uint i = 0; i < head_size; i += 4) {
vec4 k_vec = vec4(_k[i], _k[i+1], _k[i+2], _k[i+3]);
vec4 q_vec = vec4(_q[i], _q[i+1], _q[i+2], _q[i+3]);
vec4 g_vec = vec4(_g[i], _g[i+1], _g[i+2], _g[i+3]);
vec4 s_vec = vec4(state[i], state[i+1], state[i+2], state[i+3]);
vec4 kv = k_vec * v_val;
s_vec = s_vec * g_vec + kv;
y += dot(q_vec, s_vec);
state[i] = s_vec.x;
state[i+1] = s_vec.y;
state[i+2] = s_vec.z;
state[i+3] = s_vec.w;
}
dst[t] = y * scale;
}
[[unroll]] for (uint i = 0; i < head_size; i++) {
dst[T * C + batch_id * state_size + head_id * head_size * head_size
+ i * head_size + tid] = state[i];
}
}