1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
use snarkvm_fields::PrimeField;
use snarkvm_r1cs::{errors::SynthesisError, Assignment, ConstraintSystem};
use crate::{
bits::Boolean,
integers::int::*,
traits::{alloc::AllocGadget, eq::EqGadget, integers::Integer, select::CondSelectGadget},
};
macro_rules! select_int_impl {
($($gadget: ident)*) => ($(
impl<F: PrimeField> CondSelectGadget<F> for $gadget {
fn conditionally_select<CS: ConstraintSystem<F>> (
mut cs: CS,
cond: &Boolean,
first: &Self,
second: &Self,
) -> Result<Self, SynthesisError> {
if let Boolean::Constant(cond) = *cond {
if cond {
Ok(first.clone())
} else {
Ok(second.clone())
}
} else {
let result_val = cond.get_value().and_then(|c| {
if c {
first.value
} else {
second.value
}
});
let result = Self::alloc(cs.ns(|| "cond_select_result"), || result_val.get())?;
for (i, ((bit1, bit2), actual)) in first.bits.iter().zip(second.bits.iter()).zip(result.bits.iter()).enumerate() {
let expected = Boolean::conditionally_select(
&mut cs.ns(|| format!("{}_cond_select_{}", <$gadget as Integer>::SIZE, i)),
cond,
bit1,
bit2,
).unwrap();
actual.enforce_equal(&mut cs.ns(|| format!("selected_result_bit_{}", i)), &expected)?;
}
Ok(result)
}
}
fn cost() -> usize {
unimplemented!();
}
}
)*)
}
select_int_impl!(Int8 Int16 Int32 Int64 Int128);