// SiLU(gate) * up — element-wise, in-place on gate buffer.
// gate[i] = (gate[i] / (1 + exp(-gate[i]))) * up[i]
@group(0) @binding(0) var<storage, read_write> gate: array<f32>;
@group(0) @binding(1) var<storage, read> up: array<f32>;
@compute @workgroup_size(256)
fn silu_mul(@builtin(global_invocation_id) gid: vec3<u32>) {
let i = gid.x;
if (i >= arrayLength(&gate)) { return; }
let a = gate[i];
gate[i] = a / (1.0 + exp(-a)) * up[i];
}