gelu.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 X {A_TYPE data_a[];};
layout (binding = 1) writeonly buffer D {D_TYPE data_d[];};

void main() {
    const float GELU_COEF_A    = 0.044715f;
    const float SQRT_2_OVER_PI = 0.79788456080286535587989211986876f;
    const uint i = gl_GlobalInvocationID.z * 262144 + gl_GlobalInvocationID.y * 512 + gl_GlobalInvocationID.x;

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

    const float xi = float(data_a[i]);
    const float val = SQRT_2_OVER_PI*xi*(1.0f + GELU_COEF_A*xi*xi);
    data_d[i] = D_TYPE(0.5f*xi*(2.0f - 2.0f / (exp(2 * val) + 1)));
}