fix: don't deduplicate binary math of unsigned types

compiler/noirc_evaluator/src/ssa/ir/instruction.rs

@@ -406,7 +406,7 @@
             // These can fail.
             Constrain(..) | RangeCheck { .. } => true,
 
             // This should never be side-effectful
             MakeArray { .. } => false,
 
             // Some binary math can overflow or underflow
@@ -556,10 +556,22 @@
     /// If true the instruction will depend on `enable_side_effects` context during acir-gen.
     pub(crate) fn requires_acir_gen_predicate(&self, dfg: &DataFlowGraph) -> bool {
         match self {
-            Instruction::Binary(binary)
-                if matches!(binary.operator, BinaryOp::Div | BinaryOp::Mod) =>
-            {
-                true
+            Instruction::Binary(binary) => {
+                // Some binary math can overflow or underflow
+                match binary.operator {
+                    BinaryOp::Add
+                    | BinaryOp::Sub
+                    | BinaryOp::Mul
+                    | BinaryOp::Div
+                    | BinaryOp::Mod => true,
+                    BinaryOp::Eq
+                    | BinaryOp::Lt
+                    | BinaryOp::And
+                    | BinaryOp::Or
+                    | BinaryOp::Xor
+                    | BinaryOp::Shl
+                    | BinaryOp::Shr => false,
+                }
             }
 
             Instruction::ArrayGet { array, index } => {
@@ -577,7 +589,6 @@
                 _ => false,
             },
             Instruction::Cast(_, _)
-            | Instruction::Binary(_)
             | Instruction::Not(_)
             | Instruction::Truncate { .. }
             | Instruction::Constrain(_, _, _)

test_programs/execution_success/regression_6834/Nargo.toml

@@ -0,0 +1,7 @@
+[package]
+name = "regression_6834"
+version = "0.1.0"
+type = "bin"
+authors = [""]
+
+[dependencies]

test_programs/execution_success/regression_6834/Prover.toml

@@ -0,0 +1,2 @@
+year = 1
+min_age = 1

test_programs/execution_success/regression_6834/src/main.nr

@@ -0,0 +1,9 @@
+fn main(year: u32, min_age: u8) -> pub u32 {
+    if min_age == 0 {
+        (year - 2) / 4
+    } else if year > 1 {
+        (year - 2) / 4
+    } else {
+        0
+    }
+}