llama.cpp/ggml/src/ggml-vulkan/vulkan-shaders/silu_back.comp

#version 450

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

#extension GL_EXT_control_flow_attributes : enable

layout(local_size_x = 512, local_size_y = 1, local_size_z = 1) in;

layout (binding = 0) readonly buffer G {A_TYPE data_g[];};
layout (binding = 1) readonly buffer X {B_TYPE data_x[];};
layout (binding = 2) writeonly buffer D {D_TYPE data_d[];};

void main() {
    const uint i = gl_GlobalInvocationID.z * 262144 + gl_GlobalInvocationID.y * 512 + gl_GlobalInvocationID.x;

    if (i >= p.KX) {
        return;
    }

    // Compute derivative of SiLU(x): 1/(1+exp(-x)) - x*exp(-x)/(1+exp(-x))^2

    const float xi = float(data_x[i]);
    const float s = 1.0f / (1.0f + exp(-xi));
    data_d[i] = D_TYPE(data_g[i] * (s + xi * s * (1 - s)));
}