feat: Optimize x < 0 for unsigned x to false

noir-lang · Aug 8, 2023 · bae2e53 · bae2e53
1 parent a72cc96
commit bae2e53
Showing 1 changed file with 7 additions and 0 deletions.
diff --git a/crates/noirc_evaluator/src/ssa/ir/instruction.rs b/crates/noirc_evaluator/src/ssa/ir/instruction.rs
@@ -593,6 +593,13 @@ impl Binary {
                     let zero = dfg.make_constant(FieldElement::zero(), Type::bool());
                     return SimplifyResult::SimplifiedTo(zero);
                 }
+                if let Type::Numeric(NumericType::Unsigned { .. }) = operand_type {
+                    if rhs_is_zero {
+                        // Unsigned values cannot be less than zero.
+                        let zero = dfg.make_constant(FieldElement::zero(), Type::bool());
+                        return SimplifyResult::SimplifiedTo(zero);
+                    }
+                }
             }
             BinaryOp::And => {
                 if lhs_is_zero || rhs_is_zero {