tasm_lib/hashing/algebraic_hasher/
sample_scalars_static_length_kmalloc.rs

1use triton_vm::prelude::*;
2use twenty_first::math::x_field_element::EXTENSION_DEGREE;
3use twenty_first::tip5::RATE;
4
5use crate::hashing::algebraic_hasher::sample_scalars_static_length_dyn_malloc::SampleScalarsStaticLengthDynMalloc;
6use crate::hashing::squeeze_repeatedly_static_number::SqueezeRepeatedlyStaticNumber;
7use crate::prelude::*;
8
9/// Squeeze the sponge to sample a given number of [`XFieldElement`]s. Puts the scalars into
10/// statically allocated memory.
11///
12/// # Panics
13///
14/// Panics if both fields are 0 because the static allocator will be unhappy. :)
15#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
16pub struct SampleScalarsStaticLengthKMalloc {
17    pub num_elements_to_sample: usize,
18
19    /// Number of additional elements to statically allocate, in number of
20    /// [extension field element][xfe]s.
21    /// Necessary for [`Challenges`][chall].
22    ///
23    /// [chall]: crate::verifier::challenges::new_empty_input_and_output::NewEmptyInputAndOutput
24    /// [xfe]: XFieldElement
25    pub extra_capacity: usize,
26}
27
28impl SampleScalarsStaticLengthKMalloc {
29    fn num_words_to_allocate(&self) -> u32 {
30        ((self.num_elements_to_sample + self.extra_capacity) * EXTENSION_DEGREE)
31            .try_into()
32            .unwrap()
33    }
34}
35
36impl BasicSnippet for SampleScalarsStaticLengthKMalloc {
37    fn inputs(&self) -> Vec<(DataType, String)> {
38        vec![]
39    }
40
41    fn outputs(&self) -> Vec<(DataType, String)> {
42        vec![]
43    }
44
45    fn entrypoint(&self) -> String {
46        format!(
47            "tasmlib_hashing_algebraic_hasher_sample_scalars_static_length_k_malloc{}",
48            self.num_elements_to_sample
49        )
50    }
51
52    fn code(&self, library: &mut Library) -> Vec<LabelledInstruction> {
53        assert_eq!(10, RATE, "Code assumes Tip5's RATE is 10");
54        assert_eq!(3, EXTENSION_DEGREE, "Code assumes extension degree 3");
55        assert!(
56            self.extra_capacity + self.num_elements_to_sample > 0,
57            "Must allocate positive number of words"
58        );
59        let num_squeezes =
60            SampleScalarsStaticLengthDynMalloc::num_squeezes(self.num_elements_to_sample);
61
62        let num_squeezed_words = num_squeezes * RATE;
63        debug_assert!(
64            self.num_elements_to_sample * EXTENSION_DEGREE <= num_squeezed_words,
65            "need {} elements but getting {num_squeezed_words}",
66            self.num_elements_to_sample * EXTENSION_DEGREE,
67        );
68
69        let entrypoint = self.entrypoint();
70        let squeeze_repeatedly_static_number =
71            library.import(Box::new(SqueezeRepeatedlyStaticNumber { num_squeezes }));
72        let scalars_pointer_alloc = library.kmalloc(self.num_words_to_allocate());
73
74        triton_asm!(
75            {entrypoint}:
76                push {scalars_pointer_alloc.write_address()}
77                call {squeeze_repeatedly_static_number}
78                return
79        )
80    }
81}
82
83#[cfg(test)]
84pub(crate) mod tests {
85    use std::ops::Neg;
86
87    use twenty_first::util_types::sponge::Sponge;
88
89    use super::*;
90    use crate::rust_shadowing_helper_functions::array::array_get;
91    use crate::rust_shadowing_helper_functions::array::insert_as_array;
92    use crate::test_helpers::tasm_final_state;
93    use crate::test_prelude::*;
94
95    impl SampleScalarsStaticLengthKMalloc {
96        /// For testing purposes only.
97        pub fn k_malloc_address_isolated_run(&self) -> BFieldElement {
98            let dyn_allocator_state_size = 1;
99            BFieldElement::from(self.num_words_to_allocate() + dyn_allocator_state_size).neg()
100        }
101    }
102
103    impl Procedure for SampleScalarsStaticLengthKMalloc {
104        fn rust_shadow(
105            &self,
106            _stack: &mut Vec<BFieldElement>,
107            memory: &mut std::collections::HashMap<BFieldElement, BFieldElement>,
108            _nondeterminism: &NonDeterminism,
109            _public_input: &[BFieldElement],
110            sponge: &mut Option<Tip5>,
111        ) -> Vec<BFieldElement> {
112            let sponge = sponge.as_mut().expect("sponge must be initialized");
113            let num_squeezes =
114                SampleScalarsStaticLengthDynMalloc::num_squeezes(self.num_elements_to_sample);
115            let pseudorandomness = (0..num_squeezes)
116                .flat_map(|_| sponge.squeeze().to_vec())
117                .collect_vec();
118            let scalars_pointer = self.k_malloc_address_isolated_run();
119            insert_as_array(scalars_pointer, memory, pseudorandomness);
120
121            vec![]
122        }
123
124        fn pseudorandom_initial_state(
125            &self,
126            seed: [u8; 32],
127            _: Option<BenchmarkCase>,
128        ) -> ProcedureInitialState {
129            let mut rng = StdRng::from_seed(seed);
130            let stack = self.init_stack_for_isolated_run();
131            let sponge = Tip5 {
132                state: rng.random(),
133            };
134
135            ProcedureInitialState {
136                stack,
137                sponge: Some(sponge),
138                ..Default::default()
139            }
140        }
141
142        fn corner_case_initial_states(&self) -> Vec<ProcedureInitialState> {
143            let freshly_initialized_sponge = ProcedureInitialState {
144                stack: self.init_stack_for_isolated_run(),
145                sponge: Some(Tip5::init()),
146                ..Default::default()
147            };
148
149            vec![freshly_initialized_sponge]
150        }
151    }
152
153    #[test]
154    fn sample_scalars_static_length_pbt() {
155        for num_elements_to_sample in 0..11 {
156            for extra_capacity in 0..11 {
157                if num_elements_to_sample + extra_capacity == 0 {
158                    continue;
159                }
160                ShadowedProcedure::new(SampleScalarsStaticLengthKMalloc {
161                    num_elements_to_sample,
162                    extra_capacity,
163                })
164                .test();
165            }
166        }
167    }
168
169    #[proptest]
170    fn verify_agreement_with_tip5_sample_scalars(
171        #[strategy(1_usize..500)] num_elements_to_sample: usize,
172        #[strategy(1_usize..500)] extra_capacity: usize,
173        #[strategy(arb())] mut sponge: Tip5,
174    ) {
175        let snippet = SampleScalarsStaticLengthKMalloc {
176            num_elements_to_sample,
177            extra_capacity,
178        };
179        let init_stack = snippet.init_stack_for_isolated_run();
180        let tasm = tasm_final_state(
181            &ShadowedProcedure::new(snippet),
182            &init_stack,
183            &[],
184            NonDeterminism::default(),
185            &Some(sponge.clone()),
186        );
187
188        let scalar_pointer = snippet.k_malloc_address_isolated_run();
189        let read_scalar = |i| array_get(scalar_pointer, i, &tasm.ram, EXTENSION_DEGREE);
190
191        let scalars_from_tip5 = sponge.sample_scalars(num_elements_to_sample);
192        for (i, expected_scalar) in scalars_from_tip5.into_iter().enumerate() {
193            assert_eq!(expected_scalar.coefficients.to_vec(), read_scalar(i));
194        }
195    }
196}
197
198#[cfg(test)]
199mod bench {
200    use super::*;
201    use crate::test_prelude::*;
202
203    #[test]
204    fn bench_10() {
205        ShadowedProcedure::new(SampleScalarsStaticLengthKMalloc {
206            num_elements_to_sample: 10,
207            extra_capacity: 4,
208        })
209        .bench();
210    }
211
212    #[test]
213    fn bench_100() {
214        ShadowedProcedure::new(SampleScalarsStaticLengthKMalloc {
215            num_elements_to_sample: 100,
216            extra_capacity: 4,
217        })
218        .bench();
219    }
220
221    #[test]
222    fn bench_63() {
223        ShadowedProcedure::new(SampleScalarsStaticLengthKMalloc {
224            num_elements_to_sample: 63,
225            extra_capacity: 4,
226        })
227        .bench();
228    }
229}
tasm_lib/hashing/algebraic_hasher/sample_scalars_static_length_kmalloc.rs

tasm_lib/hashing/algebraic_hasher/
sample_scalars_static_length_kmalloc.rs
