Merge branch '0xPolygonZero:main' into main

.github/workflows/pr_checking.yml

@@ -0,0 +1,56 @@
+name: PR check
+
+on:
+  pull_request:
+    types: [opened, reopened, synchronize]
+
+permissions:
+  pull-requests: write
+
+jobs:
+  pr_check:
+    name: Validate PR
+    runs-on: ubuntu-latest
+    steps:
+      - name: Set up keywords
+        id: setup_keywords
+        run: echo "RESTRICTED_KEYWORDS=$(echo '${{ secrets.RESTRICTED_KEYWORDS }}' | jq -r '.[]' | tr '\n' ' ')" >> $GITHUB_ENV
+
+      - name: Check for spam PR
+        id: check
+        run: |
+          # Initialize variables to track spam presence
+          title_is_spam=false
+          description_is_spam=false
+          
+          # Check title for spam
+          for keyword in $RESTRICTED_KEYWORDS; do
+            if echo "${{ github.event.pull_request.title }}" | grep -i -q "$keyword"; then
+              title_is_spam=true
+              break
+            fi
+          done
+
+          # Check description for spam
+          for keyword in $RESTRICTED_KEYWORDS; do
+            if echo "${{ github.event.pull_request.body }}" | grep -i -q "$keyword"; then
+              description_is_spam=true
+              break
+            fi
+          done
+
+          # Set the output based on the presence of spam
+          if [ "$title_is_spam" = true ] || [ "$description_is_spam" = true ]; then
+            echo "is_spam=true" >> $GITHUB_ENV
+          else
+            echo "is_spam=false" >> $GITHUB_ENV
+          fi
+
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Close PR if spam are found and author is not a contributor or member
+        if: ${{ env.is_spam == 'true' && github.event.pull_request.author_association == 'FIRST_TIME_CONTRIBUTOR' }}
+        run: gh pr close ${{ github.event.pull_request.number }} --comment "Spam detected"
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}

field/src/lib.rs

@@ -6,7 +6,7 @@
 #![feature(specialization)]
 #![cfg_attr(target_arch = "x86_64", feature(stdarch_x86_avx512))]
 #![cfg_attr(not(test), no_std)]
-#![cfg(not(test))]
+
 extern crate alloc;
 
 pub(crate) mod arch;

field/src/types.rs

@@ -427,9 +427,13 @@ pub trait Field:
     }
 
     fn powers(&self) -> Powers<Self> {
+        self.shifted_powers(Self::ONE)
+    }
+
+    fn shifted_powers(&self, start: Self) -> Powers<Self> {
         Powers {
             base: *self,
-            current: Self::ONE,
+            current: start,
         }
     }
 
@@ -563,6 +567,7 @@ pub trait PrimeField64: PrimeField + Field64 {
 }
 
 /// An iterator over the powers of a certain base element `b`: `b^0, b^1, b^2, ...`.
+#[must_use = "iterators are lazy and do nothing unless consumed"]
 #[derive(Clone, Debug)]
 pub struct Powers<F: Field> {
     base: F,
@@ -577,6 +582,24 @@ impl<F: Field> Iterator for Powers<F> {
         self.current *= self.base;
         Some(result)
     }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        (usize::MAX, None)
+    }
+
+    fn nth(&mut self, n: usize) -> Option<F> {
+        let result = self.current * self.base.exp_u64(n.try_into().unwrap());
+        self.current = result * self.base;
+        Some(result)
+    }
+
+    fn last(self) -> Option<F> {
+        panic!("called `Iterator::last()` on an infinite sequence")
+    }
+
+    fn count(self) -> usize {
+        panic!("called `Iterator::count()` on an infinite sequence")
+    }
 }
 
 impl<F: Field> Powers<F> {
@@ -592,3 +615,26 @@ impl<F: Field> Powers<F> {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::Field;
+    use crate::goldilocks_field::GoldilocksField;
+
+    #[test]
+    fn test_powers_nth() {
+        type F = GoldilocksField;
+
+        const N: usize = 10;
+        let powers_of_two: Vec<F> = F::TWO.powers().take(N).collect();
+
+        for (n, &expect) in powers_of_two.iter().enumerate() {
+            let mut iter = F::TWO.powers();
+            assert_eq!(iter.nth(n), Some(expect));
+
+            for &expect_next in &powers_of_two[n + 1..] {
+                assert_eq!(iter.next(), Some(expect_next));
+            }
+        }
+    }
+}

plonky2/src/hash/arch/x86_64/poseidon_goldilocks_avx2_bmi2.rs

@@ -494,7 +494,7 @@ unsafe fn mds_multiply_and_add_round_const_s(
         // Fall through for MDS matrix multiplication on low 32 bits
 
         // This is a GCC _local label_. For details, see
-        // https://doc.rust-lang.org/beta/unstable-book/library-features/asm.html#labels
+        // https://doc.rust-lang.org/rust-by-example/unsafe/asm.html#labels
         // In short, the assembler makes sure to assign a unique name to replace `2:` with a unique
         // name, so the label does not clash with any compiler-generated label. `2:` can appear
         // multiple times; to disambiguate, we must refer to it as `2b` or `2f`, specifying the