tasm_lib/list/
length.rs

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
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
use std::collections::HashMap;

use itertools::Itertools;
use num::One;
use rand::prelude::*;
use triton_vm::prelude::*;

use crate::data_type::DataType;
use crate::empty_stack;
use crate::library::Library;
use crate::rust_shadowing_helper_functions::list::untyped_insert_random_list;
use crate::traits::deprecated_snippet::DeprecatedSnippet;
use crate::InitVmState;

#[derive(Debug, Clone, Eq, PartialEq, Hash)]
pub struct Length {
    pub element_type: DataType,
}

impl Length {
    pub fn new(data_type: DataType) -> Self {
        Self {
            element_type: data_type,
        }
    }
}

impl DeprecatedSnippet for Length {
    fn entrypoint_name(&self) -> String {
        format!(
            "tasmlib_list_length___{}",
            self.element_type.label_friendly_name()
        )
    }

    fn input_field_names(&self) -> Vec<String> {
        vec!["*list".to_string()]
    }

    fn input_types(&self) -> Vec<DataType> {
        vec![DataType::List(Box::new(self.element_type.clone()))]
    }

    fn output_field_names(&self) -> Vec<String> {
        vec!["list_length".to_string()]
    }

    fn output_types(&self) -> Vec<DataType> {
        vec![DataType::U32]
    }

    fn stack_diff(&self) -> isize {
        // Consumes a memory address and returns a length in the form of a u32
        0
    }

    fn function_code(&self, _library: &mut Library) -> String {
        let entry_point = self.entrypoint_name();
        // BEFORE: _ *list
        // AFTER:  _ list_length_u32
        triton_asm!(
            {entry_point}:
                read_mem 1
                pop 1
                return
        )
        .iter()
        .join("\n")
    }

    fn crash_conditions(&self) -> Vec<String> {
        vec![]
    }

    fn gen_input_states(&self) -> Vec<InitVmState> {
        let mut ret: Vec<InitVmState> = vec![];
        let mut rng = thread_rng();
        let mut stack = empty_stack();
        let list_address: BFieldElement = random();
        let list_length: usize = rng.gen_range(0..100);
        stack.push(list_address);

        // Test for various values of `N` (list-element size)
        let mut memory = HashMap::default();
        untyped_insert_random_list(list_address, list_length, &mut memory, 1);
        ret.push(InitVmState::with_stack_and_memory(stack.clone(), memory));
        memory = HashMap::default();
        untyped_insert_random_list(list_address, list_length, &mut memory, 2);
        ret.push(InitVmState::with_stack_and_memory(stack.clone(), memory));
        memory = HashMap::default();
        untyped_insert_random_list(list_address, list_length, &mut memory, 3);
        ret.push(InitVmState::with_stack_and_memory(stack.clone(), memory));
        memory = HashMap::default();
        untyped_insert_random_list(list_address, list_length, &mut memory, 4);
        ret.push(InitVmState::with_stack_and_memory(stack.clone(), memory));
        memory = HashMap::default();
        untyped_insert_random_list(list_address, list_length, &mut memory, 11);
        ret.push(InitVmState::with_stack_and_memory(stack, memory));

        ret
    }

    fn common_case_input_state(&self) -> InitVmState {
        let mut stack = empty_stack();
        let list_address: u32 = random();
        let list_address = BFieldElement::from(list_address as u64);
        stack.push(list_address);
        let mut memory = HashMap::default();
        untyped_insert_random_list(BFieldElement::one(), 1 << 5, &mut memory, 1);
        InitVmState::with_stack_and_memory(stack.clone(), memory)
    }

    fn worst_case_input_state(&self) -> InitVmState {
        let mut stack = empty_stack();
        let list_address: u32 = random();
        let list_address = BFieldElement::from(list_address as u64);
        stack.push(list_address);
        let mut memory = HashMap::default();
        untyped_insert_random_list(BFieldElement::one(), 1 << 6, &mut memory, 1);
        InitVmState::with_stack_and_memory(stack.clone(), memory)
    }

    fn rust_shadowing(
        &self,
        stack: &mut Vec<BFieldElement>,
        _std_in: Vec<BFieldElement>,
        _secret_in: Vec<BFieldElement>,
        memory: &mut HashMap<BFieldElement, BFieldElement>,
    ) {
        // Find the list in memory and push its length to the top of the stack
        let list_address = stack.pop().unwrap();
        let list_length = memory[&list_address];
        stack.push(list_length);
    }
}

#[cfg(test)]
mod tests {
    use rand::prelude::*;

    use super::*;
    use crate::test_helpers::test_rust_equivalence_given_input_values_deprecated;
    use crate::test_helpers::test_rust_equivalence_multiple_deprecated;

    #[test]
    fn new_snippet_test_long() {
        fn test_rust_equivalence_and_export(data_type: DataType) {
            test_rust_equivalence_multiple_deprecated(
                &Length {
                    element_type: data_type,
                },
                true,
            );
        }

        test_rust_equivalence_and_export(DataType::Bfe);
        test_rust_equivalence_and_export(DataType::U64);
        test_rust_equivalence_and_export(DataType::Digest);
    }

    #[test]
    fn list_u32_simple_long() {
        let expected_end_stack = [empty_stack(), vec![BFieldElement::new(42)]].concat();
        prop_length_long(BFieldElement::one(), 42, Some(&expected_end_stack));

        let expected_end_stack = [empty_stack(), vec![BFieldElement::new(588)]].concat();
        prop_length_long(BFieldElement::one(), 588, Some(&expected_end_stack));
    }

    // Note that the *actual list* of length `list_length` is *actually constructed in the VM in this test. So you may not
    // want to exaggerate that number.
    fn prop_length_long(
        list_address: BFieldElement,
        list_length: u32,
        expected: Option<&[BFieldElement]>,
    ) {
        let mut init_stack = empty_stack();
        init_stack.push(list_address);

        let mut init_memory = HashMap::default();

        // Insert length indicator of list, lives on offset = 0 from `list_address`
        init_memory.insert(list_address, BFieldElement::new(list_length as u64));

        // Insert random values for the elements in the list
        let mut rng = thread_rng();
        for i in 0..list_length {
            init_memory.insert(
                list_address + BFieldElement::new((i + 1) as u64),
                BFieldElement::new(rng.next_u64()),
            );
        }

        let data_type = DataType::Bfe;
        test_rust_equivalence_given_input_values_deprecated(
            &Length {
                element_type: data_type,
            },
            &init_stack,
            &[],
            init_memory,
            expected,
        );
    }
}

#[cfg(test)]
mod benches {
    use super::*;
    use crate::snippet_bencher::bench_and_write;

    #[test]
    fn length_long_benchmark() {
        bench_and_write(Length::new(DataType::Digest));
    }
}