Влияние проверки условия для выполнения функции на производительность.

HRESULT CDECL wined3d_device_get_ps_consts_f(const struct wined3d_device *device,
        UINT start_register, float *constants, UINT vector4f_count)
{
    const struct wined3d_d3d_info *d3d_info = &device->adapter->d3d_info;
    int count = min(vector4f_count, d3d_info->limits.ps_uniform_count - start_register);

    TRACE("device %p, start_register %u, constants %p, vector4f_count %u.\n",
            device, start_register, constants, vector4f_count);

    if (!constants || count < 0)
        return WINED3DERR_INVALIDCALL;

    memcpy(constants, &device->state.ps_consts_f[start_register * 4], count * sizeof(float) * 4);

    return WINED3D_OK;
}