fixes (a16z#507)

WillPapper · Nov 20, 2024 · 856c594 · 856c594
1 parent c90d6f9
commit 856c594
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Showing 2 changed files with 15 additions and 6 deletions.
diff --git a/jolt-core/src/jolt/instruction/virtual_assert_valid_signed_remainder.rs b/jolt-core/src/jolt/instruction/virtual_assert_valid_signed_remainder.rs
@@ -95,7 +95,9 @@ impl<const WORD_SIZE: usize> JoltInstruction for AssertValidSignedRemainderInstr
                 } else {
                     let remainder_sign = remainder >> 31;
                     let divisor_sign = divisor >> 31;
-                    (remainder.abs() < divisor.abs() && remainder_sign == divisor_sign).into()
+                    (remainder.unsigned_abs() < divisor.unsigned_abs()
+                        && remainder_sign == divisor_sign)
+                        .into()
                 }
             }
             64 => {
@@ -109,7 +111,9 @@ impl<const WORD_SIZE: usize> JoltInstruction for AssertValidSignedRemainderInstr
                 } else {
                     let remainder_sign = remainder >> 63;
                     let divisor_sign = divisor >> 63;
-                    (remainder.abs() < divisor.abs() && remainder_sign == divisor_sign).into()
+                    (remainder.unsigned_abs() < divisor.unsigned_abs()
+                        && remainder_sign == divisor_sign)
+                        .into()
                 }
             }
             _ => panic!("Unsupported WORD_SIZE: {}", WORD_SIZE),
@@ -161,6 +165,7 @@ mod test {
 
         // Edge cases
         let u32_max: u64 = u32::MAX as u64;
+        let i32_min: u64 = i32::MIN as u32 as u64;
         let instructions = vec![
             AssertValidSignedRemainderInstruction::<WORD_SIZE>(100, 0),
             AssertValidSignedRemainderInstruction::<WORD_SIZE>(0, 100),
@@ -170,6 +175,8 @@ mod test {
             AssertValidSignedRemainderInstruction::<WORD_SIZE>(u32_max, u32_max),
             AssertValidSignedRemainderInstruction::<WORD_SIZE>(u32_max, 1 << 8),
             AssertValidSignedRemainderInstruction::<WORD_SIZE>(1 << 8, u32_max),
+            AssertValidSignedRemainderInstruction::<WORD_SIZE>(4294967295, 3909118204),
+            AssertValidSignedRemainderInstruction::<WORD_SIZE>(i32_min, i32_min),
         ];
         for instruction in instructions {
             jolt_instruction_test!(instruction);
@@ -199,6 +206,7 @@ mod test {
 
         // Edge cases
         let u64_max: u64 = u64::MAX;
+        let i64_min: u64 = i64::MIN as u64;
         let instructions = vec![
             AssertValidSignedRemainderInstruction::<WORD_SIZE>(100, 0),
             AssertValidSignedRemainderInstruction::<WORD_SIZE>(0, 100),
@@ -210,6 +218,7 @@ mod test {
             AssertValidSignedRemainderInstruction::<WORD_SIZE>(1 << 8, u64_max),
             AssertValidSignedRemainderInstruction::<WORD_SIZE>(u64_max, 1 << 40),
             AssertValidSignedRemainderInstruction::<WORD_SIZE>(u64_max, u64_max - 1),
+            AssertValidSignedRemainderInstruction::<WORD_SIZE>(i64_min, i64_min),
         ];
         for instruction in instructions {
             jolt_instruction_test!(instruction);

diff --git a/jolt-core/src/jolt/instruction/virtual_assert_valid_unsigned_remainder.rs b/jolt-core/src/jolt/instruction/virtual_assert_valid_unsigned_remainder.rs
@@ -31,12 +31,12 @@ impl<const WORD_SIZE: usize> JoltInstruction
         let mut sum = F::zero();
         let mut eq_prod = F::one();
 
-        for i in 0..C {
+        for i in 0..C - 1 {
             sum += ltu[i] * eq_prod;
             eq_prod *= eq[i];
         }
-        // LTU(r, y) + EQ(y, 0)
-        sum + divisor_is_zero
+        // LTU(x, y) + EQ(y, 0)
+        sum + ltu[C - 1] * eq_prod + divisor_is_zero
     }
 
     fn g_poly_degree(&self, C: usize) -> usize {
@@ -50,7 +50,7 @@ impl<const WORD_SIZE: usize> JoltInstruction
     ) -> Vec<(Box<dyn LassoSubtable<F>>, SubtableIndices)> {
         vec![
             (Box::new(LtuSubtable::new()), SubtableIndices::from(0..C)),
-            (Box::new(EqSubtable::new()), SubtableIndices::from(0..C)),
+            (Box::new(EqSubtable::new()), SubtableIndices::from(0..C - 1)),
             (
                 Box::new(RightIsZeroSubtable::new()),
                 SubtableIndices::from(0..C),