example lookup data

crates/air_utils/src/lib.rs

@@ -1,2 +1,2 @@
-#![feature(exact_size_is_empty, raw_slice_split, portable_simd)]
+#![feature(exact_size_is_empty, raw_slice_split, portable_simd, array_chunks)]
 pub mod trace;

crates/air_utils/src/trace/examle_lookup_data.rs

@@ -0,0 +1,228 @@
+// TODO(Ohad): write a derive macro for this.
+use rayon::iter::plumbing::{bridge, Consumer, Producer, ProducerCallback, UnindexedConsumer};
+use rayon::prelude::*;
+use stwo_prover::core::backend::simd::m31::{PackedM31, N_LANES};
+
+pub struct LookupData {
+    pub lu0: Vec<[PackedM31; 2]>,
+    pub lu1: Vec<[PackedM31; 4]>,
+}
+impl LookupData {
+    /// # Safety
+    pub unsafe fn uninitialized(log_size: u32) -> Self {
+        let length = 1 << log_size;
+        let n_simd_elems = length / N_LANES;
+        let mut lu0 = Vec::with_capacity(n_simd_elems);
+        let mut lu1 = Vec::with_capacity(n_simd_elems);
+        lu0.set_len(n_simd_elems);
+        lu1.set_len(n_simd_elems);
+
+        Self { lu0, lu1 }
+    }
+
+    pub fn iter_mut(&mut self) -> LookupDataIterMut<'_> {
+        LookupDataIterMut::new(&mut self.lu0, &mut self.lu1)
+    }
+
+    pub fn par_iter_mut(&mut self) -> ParLookupDataIterMut<'_> {
+        ParLookupDataIterMut {
+            lu0: &mut self.lu0,
+            lu1: &mut self.lu1,
+        }
+    }
+}
+
+pub struct LookupDataMutChunk<'trace> {
+    pub lu0: &'trace mut [PackedM31; 2],
+    pub lu1: &'trace mut [PackedM31; 4],
+}
+pub struct LookupDataIterMut<'trace> {
+    lu0: *mut [[PackedM31; 2]],
+    lu1: *mut [[PackedM31; 4]],
+    phantom: std::marker::PhantomData<&'trace ()>,
+}
+impl<'trace> LookupDataIterMut<'trace> {
+    pub fn new(slice0: &'trace mut [[PackedM31; 2]], slice1: &'trace mut [[PackedM31; 4]]) -> Self {
+        Self {
+            lu0: slice0 as *mut _,
+            lu1: slice1 as *mut _,
+            phantom: std::marker::PhantomData,
+        }
+    }
+}
+impl<'trace> Iterator for LookupDataIterMut<'trace> {
+    type Item = LookupDataMutChunk<'trace>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.lu0.is_empty() {
+            return None;
+        }
+        let item = unsafe {
+            let (head0, tail0) = self.lu0.split_at_mut(1);
+            let (head1, tail1) = self.lu1.split_at_mut(1);
+            self.lu0 = tail0;
+            self.lu1 = tail1;
+            LookupDataMutChunk {
+                lu0: &mut (*head0)[0],
+                lu1: &mut (*head1)[0],
+            }
+        };
+        Some(item)
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        let len = self.lu0.len();
+        (len, Some(len))
+    }
+}
+
+impl ExactSizeIterator for LookupDataIterMut<'_> {}
+impl DoubleEndedIterator for LookupDataIterMut<'_> {
+    fn next_back(&mut self) -> Option<Self::Item> {
+        if self.lu0.is_empty() {
+            return None;
+        }
+        let item = unsafe {
+            let (head0, tail0) = self.lu0.split_at_mut(self.lu0.len() - 1);
+            let (head1, tail1) = self.lu1.split_at_mut(self.lu1.len() - 1);
+            self.lu0 = head0;
+            self.lu1 = head1;
+            LookupDataMutChunk {
+                lu0: &mut (*tail0)[0],
+                lu1: &mut (*tail1)[0],
+            }
+        };
+        Some(item)
+    }
+}
+
+struct RowProducer<'trace> {
+    lu0: &'trace mut [[PackedM31; 2]],
+    lu1: &'trace mut [[PackedM31; 4]],
+}
+
+impl<'trace> Producer for RowProducer<'trace> {
+    type Item = LookupDataMutChunk<'trace>;
+
+    fn split_at(self, index: usize) -> (Self, Self) {
+        let (lu0, rh0) = self.lu0.split_at_mut(index);
+        let (lu1, rh1) = self.lu1.split_at_mut(index);
+        (RowProducer { lu0, lu1 }, RowProducer { lu0: rh0, lu1: rh1 })
+    }
+
+    type IntoIter = LookupDataIterMut<'trace>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        LookupDataIterMut::new(self.lu0, self.lu1)
+    }
+}
+
+pub struct ParLookupDataIterMut<'trace> {
+    lu0: &'trace mut [[PackedM31; 2]],
+    lu1: &'trace mut [[PackedM31; 4]],
+}
+
+impl<'trace> ParLookupDataIterMut<'trace> {
+    pub fn new(slice0: &'trace mut [[PackedM31; 2]], slice1: &'trace mut [[PackedM31; 4]]) -> Self {
+        Self {
+            lu0: slice0,
+            lu1: slice1,
+        }
+    }
+}
+
+impl<'trace> ParallelIterator for ParLookupDataIterMut<'trace> {
+    type Item = LookupDataMutChunk<'trace>;
+
+    fn drive_unindexed<D>(self, consumer: D) -> D::Result
+    where
+        D: UnindexedConsumer<Self::Item>,
+    {
+        bridge(self, consumer)
+    }
+
+    fn opt_len(&self) -> Option<usize> {
+        Some(self.len())
+    }
+}
+
+impl IndexedParallelIterator for ParLookupDataIterMut<'_> {
+    fn len(&self) -> usize {
+        self.lu0.len()
+    }
+
+    fn drive<D: Consumer<Self::Item>>(self, consumer: D) -> D::Result {
+        bridge(self, consumer)
+    }
+
+    fn with_producer<CB: ProducerCallback<Self::Item>>(self, callback: CB) -> CB::Output {
+        callback.callback(RowProducer {
+            lu0: self.lu0,
+            lu1: self.lu1,
+        })
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use itertools::{all, Itertools};
+    use rayon::iter::{IndexedParallelIterator, ParallelIterator};
+    use rayon::slice::ParallelSlice;
+    use stwo_prover::core::backend::simd::m31::{PackedM31, N_LANES};
+    use stwo_prover::core::fields::m31::M31;
+
+    use crate::trace::examle_lookup_data::LookupData;
+    use crate::trace::iterable_trace::IterableTrace;
+
+    #[test]
+    fn test_lookup_data() {
+        const N_COLUMNS: usize = 5;
+        const LOG_SIZE: u32 = 8;
+        let mut trace = IterableTrace::<N_COLUMNS>::zeroed(LOG_SIZE);
+        let arr = (0..1 << LOG_SIZE).map(M31::from).collect_vec();
+        let mut lookup_data = unsafe { LookupData::uninitialized(LOG_SIZE) };
+        let expected: (Vec<_>, Vec<_>) = arr
+            .array_chunks::<N_LANES>()
+            .map(|x| {
+                let x = PackedM31::from_array(*x);
+                let x1 = x + PackedM31::broadcast(M31(1));
+                let x2 = x + x1;
+                let x3 = x + x1 + x2;
+                let x4 = x + x1 + x2 + x3;
+                ([x, x4], [x1, x1.double(), x2, x2.double()])
+            })
+            .unzip();
+
+        trace
+            .par_iter_mut()
+            .zip(arr.par_chunks(N_LANES))
+            .zip(lookup_data.par_iter_mut())
+            .chunks(4)
+            .for_each(|chunk| {
+                chunk.into_iter().for_each(|((row, input), lookup_data)| {
+                    *row[0] = PackedM31::from_array(input.try_into().unwrap());
+                    *row[1] = *row[0] + PackedM31::broadcast(M31(1));
+                    *row[2] = *row[0] + *row[1];
+                    *row[3] = *row[0] + *row[1] + *row[2];
+                    *row[4] = *row[0] + *row[1] + *row[2] + *row[3];
+                    *lookup_data.lu0 = [*row[0], *row[4]];
+                    *lookup_data.lu1 = [*row[1], row[1].double(), *row[2], row[2].double()];
+                })
+            });
+
+        assert!(all(
+            lookup_data.lu0.into_iter().zip(expected.0),
+            |(actual, expected)| actual[0].to_array() == expected[0].to_array()
+                && actual[1].to_array() == expected[1].to_array()
+        ));
+        assert!(all(
+            lookup_data.lu1.into_iter().zip(expected.1),
+            |(actual, expected)| {
+                actual[0].to_array() == expected[0].to_array()
+                    && actual[1].to_array() == expected[1].to_array()
+                    && actual[2].to_array() == expected[2].to_array()
+                    && actual[3].to_array() == expected[3].to_array()
+            }
+        ));
+    }
+}

crates/air_utils/src/trace/mod.rs

@@ -1 +1,2 @@
+pub mod examle_lookup_data;
 pub mod iterable_trace;