#version 450
#extension GL_EXT_control_flow_attributes : require
// Fan one stream back out to hc streams and add the combination-weighted
// residuals:
//
// dst[i0, idst, it] = x[i0, it]*post[idst, it]
// + sum_isrc residual[i0, isrc, it]*comb[idst, isrc, it]
layout(constant_id = 0) const uint BLOCK_SIZE = 256;
layout(local_size_x_id = 0, local_size_y = 1, local_size_z = 1) in;
layout(push_constant) uniform parameter
{
uint n_embd;
uint n_tokens;
uint nbx0; uint nbx1; // x
uint nbr0; uint nbr1; uint nbr2; // residual
uint nbp0; uint nbp1; // post
uint nbc0; uint nbc1; uint nbc2; // comb
uint nbd0; uint nbd1; uint nbd2; // dst
uint x_offset;
uint r_offset;
uint p_offset;
uint c_offset;
uint d_offset;
};
layout(binding = 0, std430) readonly buffer X { float data_x[]; };
layout(binding = 1, std430) readonly buffer R { float data_r[]; };
layout(binding = 2, std430) readonly buffer P { float data_p[]; };
layout(binding = 3, std430) readonly buffer C { float data_c[]; };
layout(binding = 4, std430) writeonly buffer D { float data_d[]; };
const uint hc = 4;
shared float post_s[hc];
shared float comb_s[hc * hc];
void main() {
const uint tid = gl_LocalInvocationID.x;
const uint it = gl_WorkGroupID.y;
if (tid < hc) {
post_s[tid] = data_p[p_offset + tid * nbp0 + it * nbp1];
}
if (tid < hc * hc) {
const uint idst = tid & 3;
const uint isrc = tid >> 2;
comb_s[tid] = data_c[c_offset + idst * nbc0 + isrc * nbc1 + it * nbc2];
}
barrier();
// After the barrier, so every invocation reaches it.
const uint i0 = gl_WorkGroupID.x * BLOCK_SIZE + tid;
if (i0 >= n_embd) {
return;
}
const float xv = data_x[x_offset + i0 * nbx0 + it * nbx1];
const uint rb = r_offset + i0 * nbr0 + it * nbr2;
float r[hc];
[[unroll]]
for (uint isrc = 0; isrc < hc; ++isrc) {
r[isrc] = data_r[rb + isrc * nbr1];
}
[[unroll]]
for (uint idst = 0; idst < hc; ++idst) {
float result = xv * post_s[idst];
[[unroll]]
for (uint isrc = 0; isrc < hc; ++isrc) {
result = fma(r[isrc], comb_s[idst + hc * isrc], result);
}
data_d[d_offset + i0 * nbd0 + idst * nbd1 + it * nbd2] = result;
}
}