fix: avoid division and modulo hoisting around side effect variables

compiler/noirc_evaluator/src/ssa/opt/remove_enable_side_effects.rs

@@ -110,11 +110,9 @@ fn responds_to_side_effects_var(dfg: &DataFlowGraph, instruction: &Instruction)
                 dfg.type_of_value(binary.lhs).is_unsigned()
             }
             BinaryOp::Div | BinaryOp::Mod => {
-                if let Some(rhs) = dfg.get_numeric_constant(binary.rhs) {
-                    rhs == FieldElement::zero()
-                } else {
-                    true
-                }
+                // Even with non zero rhs, division and modulo respond to side effects because they
+                // use non-deterministic outputs which will be affected by the side effects var.
+                true
             }
             _ => false,
         },

test_programs/execution_success/regression_8261/Nargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "regression_8261"
+type = "bin"
+authors = [""]
+
+[dependencies]

test_programs/execution_success/regression_8261/Prover.toml

@@ -0,0 +1,29 @@
+a = true
+b = [
+    [
+        true,
+        false,
+    ],
+    [
+        true,
+        true,
+    ],
+    "\u0014w",
+    [
+        "0x000000000000000000000000000000000000000000000000000000000000dd8e",
+        "0x00000000000000000000000000000000000000000000000000000000000002cc",
+    ],
+    "0x000000000000000000000000000000000000000000000000000000000000137c",
+]
+c = [
+    [
+        "0x1eac91250e5e424f9c8b3eb451e0b343131fcf4342053cfad6337e7ca1350adb",
+        "",
+        false,
+        false,
+    ],
+    [
+        "0x000000000000000000000000000000000000000000000000000000000000c456",
+        "\u001B\"",
+    ],
+]

test_programs/execution_success/regression_8261/src/main.nr

@@ -0,0 +1,16 @@
+fn main(
+    a: bool,
+    b: ([bool; 2], [bool; 2], str<2>, (u16, u16), u16),
+    c: ((Field, str<0>, bool, bool), (u16, str<2>)),
+) -> pub u16 {
+    b.4
+        % if c.0.2 {
+            b.3.0
+        } else {
+            if (!a) {
+                37995
+            } else {
+                (b.3.1 % 64485)
+            }
+        }
+}

test_programs/execution_success/regression_8261/stdout.txt

@@ -0,0 +1 @@
+[regression_8261] Circuit output: Field(692)