in uint a;
void main() {
    sk_FragColor.xy = half2(unpackHalf2x16(a));
    sk_FragColor.xy = half2(unpackUnorm2x16(a));
    sk_FragColor.xy = half2(unpackSnorm2x16(a));
    sk_FragColor = half4(unpackUnorm4x8(a));
    sk_FragColor = half4(unpackSnorm4x8(a));
}