llama.cpp/vulkan-shaders/sum_rows.comp

#version 450

#include "generic_head.comp"
#include "types.comp"

#extension GL_EXT_control_flow_attributes : enable
layout(local_size_x_id = 0, local_size_y = 1, local_size_z = 1) in;

layout (binding = 0) readonly buffer A {A_TYPE data_a[];};
layout (binding = 1) writeonly buffer D {D_TYPE data_d[];};

layout (constant_id = 0) const uint BLOCK_SIZE = 32;

shared FLOAT_TYPE tmp[BLOCK_SIZE];

void main() {
    const uint row = gl_WorkGroupID.x;
    const uint col = gl_LocalInvocationID.x;

    tmp[col] = FLOAT_TYPE(0.0f);

    for (uint i = col; i < p.KX; i += BLOCK_SIZE) {
        tmp[col] += FLOAT_TYPE(data_a[row*p.KX + i]);
    }

    barrier();
    [[unroll]] for (int s = int(BLOCK_SIZE) / 2; s > 0; s >>= 1) {
        if (col < s) {
            tmp[col] += tmp[col + s];
        }
        barrier();
    }

    if (col == 0) {
        data_d[row] = D_TYPE(tmp[0]);
    }
}