| 104 | |
| 105 | #[test] |
| 106 | fn test_sub() { |
| 107 | let mut prng = ChaCha20Rng::seed_from_u64(0); |
| 108 | |
| 109 | for _ in 0..100 { |
| 110 | let a: BigUint = prng.sample(RandomBits::new(254)); |
| 111 | let b: BigUint = prng.sample(RandomBits::new(254)); |
| 112 | let mut c: BigUint = BigUint::one().shl(254) + &a - &b; |
| 113 | c = c.rem(BigUint::one().shl(254)); |
| 114 | |
| 115 | let script = script! { |
| 116 | { U254::push_u32_le(&a.to_u32_digits()) } |
| 117 | { U254::push_u32_le(&b.to_u32_digits()) } |
| 118 | { U254::sub(1, 0) } |
| 119 | { U254::push_u32_le(&c.to_u32_digits()) } |
| 120 | { U254::equalverify(1, 0) } |
| 121 | OP_TRUE |
| 122 | }; |
| 123 | run(script); |
| 124 | |
| 125 | let script = script! { |
| 126 | { U254::push_u32_le(&b.to_u32_digits()) } |
| 127 | { U254::push_u32_le(&a.to_u32_digits()) } |
| 128 | { U254::sub(0, 1) } |
| 129 | { U254::push_u32_le(&c.to_u32_digits()) } |
| 130 | { U254::equalverify(1, 0) } |
| 131 | OP_TRUE |
| 132 | }; |
| 133 | run(script); |
| 134 | } |
| 135 | |
| 136 | for _ in 0..100 { |
| 137 | let a: BigUint = prng.sample(RandomBits::new(64)); |
| 138 | let b: BigUint = prng.sample(RandomBits::new(64)); |
| 139 | let mut c: BigUint = BigUint::one().shl(64) + &a - &b; |
| 140 | c = c.rem(BigUint::one().shl(64)); |
| 141 | |
| 142 | let script = script! { |
| 143 | { U64::push_u32_le(&a.to_u32_digits()) } |
| 144 | { U64::push_u32_le(&b.to_u32_digits()) } |
| 145 | { U64::sub(1, 0) } |
| 146 | { U64::push_u32_le(&c.to_u32_digits()) } |
| 147 | { U64::equalverify(1, 0) } |
| 148 | OP_TRUE |
| 149 | }; |
| 150 | run(script); |
| 151 | |
| 152 | let script = script! { |
| 153 | { U64::push_u32_le(&b.to_u32_digits()) } |
| 154 | { U64::push_u32_le(&a.to_u32_digits()) } |
| 155 | { U64::sub(0, 1) } |
| 156 | { U64::push_u32_le(&c.to_u32_digits()) } |
| 157 | { U64::equalverify(1, 0) } |
| 158 | OP_TRUE |
| 159 | }; |
| 160 | run(script); |
| 161 | } |
| 162 | } |
| 163 | |