diff --git a/front/hir/src/conversions.rs b/front/hir/src/conversions.rs
index de8687c8..c4a0b079 100644
--- a/front/hir/src/conversions.rs
+++ b/front/hir/src/conversions.rs
@@ -17,6 +17,7 @@ use super::{ExpressionId, HirExpressionType, TypedProgram};
 use error::SourceSpan;
 use parser::ast::{AssignOperator, Expression, Literal, Operator, WaveType};
 use std::collections::HashSet;
+use utils::const_int::ConstInt;
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
 pub enum ConversionMode {
@@ -216,6 +217,35 @@ fn literal(expr: &Expression) -> bool {
     }
 }
 
+/// Truthiness observes the whole untyped token before any integer narrowing.
+/// Keep the usual i32 representation when it fits, then use an existing Wave
+/// width that preserves the value. Typed operands retain their declared width.
+fn boolean_literal_type(mut expr: &Expression) -> Option<WaveType> {
+    let mut negative = false;
+    loop {
+        match expr.unspanned() {
+            Expression::Grouped(inner) => expr = inner,
+            Expression::Unary { operator: Operator::Neg, expr: inner } => {
+                negative = !negative;
+                expr = inner;
+            },
+            Expression::Literal(Literal::Int(raw)) => {
+                let token = lexer::number::IntegerLiteral::parse(raw)?;
+                let mut value = ConstInt::from_digits(&token.digits, token.radix)?;
+                if negative ^ token.negative {
+                    value = value.negated();
+                }
+                return [32, 64, 128, 256, 512, 1024]
+                    .into_iter()
+                    .find(|&bits| value.fits(bits, true))
+                    .map(WaveType::Int)
+                    .or_else(|| value.fits(1024, false).then_some(WaveType::Uint(1024)));
+            },
+            _ => return None,
+        }
+    }
+}
+
 pub(super) fn build(program: &TypedProgram) -> Vec<Option<NumericExpressionInfo>> {
     let mut planner =
         Planner { program, facts: vec![None; program.expression_count()], seen: HashSet::new() };
@@ -236,9 +266,11 @@ impl Planner<'_> {
         match self.program.type_of(expr)? {
             HirExpressionType::Resolved(ty) if scalar(ty) => Some(ty.clone()),
             HirExpressionType::IntegerLiteral => Some(
-                hint.filter(|t| numeric(t) && **t != WaveType::Bool)
-                    .cloned()
-                    .unwrap_or(WaveType::Int(32)),
+                if hint == Some(&WaveType::Bool) {
+                    boolean_literal_type(expr).unwrap_or(WaveType::Int(1024))
+                } else {
+                    hint.filter(|t| numeric(t)).cloned().unwrap_or(WaveType::Int(32))
+                },
             ),
             HirExpressionType::FloatLiteral => Some(
                 hint.filter(|t| matches!(t, WaveType::Float(_)))
@@ -318,7 +350,7 @@ impl Planner<'_> {
                 } else {
                     literal(inner).then(|| {
                         if target_type == &WaveType::Bool {
-                            WaveType::Int(1024)
+                            boolean_literal_type(inner).unwrap_or(WaveType::Int(1024))
                         } else if pointer(target_type) {
                             WaveType::Int(64)
                         } else {
@@ -429,7 +461,7 @@ impl Planner<'_> {
             },
             Expression::Unary { operator, expr: inner } => {
                 let input = if matches!(operator, Operator::Not | Operator::LogicalNot) {
-                    self.plan(inner, None, None)?
+                    self.plan(inner, None, boolean_literal_type(inner))?
                 } else {
                     self.plan(inner, None, hint.cloned())?
                 };
@@ -702,6 +734,38 @@ fun check(n: i64, f: f64) {
         assert!(p.verify_conversions().is_err());
     }
 
+    #[test]
+    fn boolean_literal_widths_preserve_values_without_changing_typed_wrap() {
+        for (literal, expected) in [
+            ("0", WaveType::Int(32)),
+            ("2147483647", WaveType::Int(32)),
+            ("2147483648", WaveType::Int(64)),
+            ("4294967296", WaveType::Int(64)),
+            ("9223372036854775808", WaveType::Int(128)),
+            ("18446744073709551616", WaveType::Int(128)),
+            ("170141183460469231731687303715884105728", WaveType::Int(256)),
+        ] {
+            for source in [format!("{literal} as bool"), format!("true && ({literal})")] {
+                let p = program(&format!("fun check() {{ var value: bool = {source}; }}"));
+                p.verify_conversions().unwrap();
+                let expression = initializer(&p, 0);
+                let operand = match expression {
+                    Expression::Cast { expr, .. } => expr.as_ref(),
+                    Expression::BinaryExpression { right, .. } => {
+                        let Expression::Grouped(inner) = right.as_ref() else { panic!() };
+                        inner.as_ref()
+                    },
+                    _ => panic!(),
+                };
+                assert_eq!(p.numeric_expression_of(operand).unwrap().evaluation_type, expected);
+            }
+        }
+        let p = program("fun check() { var value: bool = (4294967296 as i32) as bool; }");
+        let fact = p.numeric_expression_of(initializer(&p, 0)).unwrap();
+        assert_eq!(fact.evaluation_type, WaveType::Int(32));
+        assert_eq!(fact.conversions[0].source_type, WaveType::Int(32));
+    }
+
     #[test]
     fn ordered_casts_preserve_truncation_signedness_modes_and_spans() {
         let source = "fun check(x: i32) { var y: i64 = x as u8 as i32; var z: u32 = x as u32; var identity: i32 = x as i32; }";
diff --git a/front/parser/src/verification/expression.rs b/front/parser/src/verification/expression.rs
index 323fe412..b5c26fec 100644
--- a/front/parser/src/verification/expression.rs
+++ b/front/parser/src/verification/expression.rs
@@ -211,6 +211,14 @@ impl Validator<'_> {
             SemanticSpanKind::Keyword,
             operator_source_symbol(operator).unwrap_or("binary operator"),
         );
+        if matches!(operator, Operator::LogicalAnd | Operator::LogicalOr) {
+            // Logical operands are independently tested for nonzero. Neither
+            // operand supplies a calculation width for the other, and the
+            // boolean result does not narrow an untyped integer token.
+            let left_type = self.validate_expr(left)?;
+            let right_type = self.validate_expr(right)?;
+            return infer_binary_type(self.program, operator, left_type, right_type);
+        }
         if matches!(operator, Operator::ShiftLeft | Operator::ShiftRight) {
             let left_type = self.validate_expr_expected(left, expected)?;
             let right_type = self.validate_expr(right)?;
diff --git a/llvm/src/codegen/arithmetic_runtime/mod.rs b/llvm/src/codegen/arithmetic_runtime/mod.rs
index bbcd56b0..f02021b7 100644
--- a/llvm/src/codegen/arithmetic_runtime/mod.rs
+++ b/llvm/src/codegen/arithmetic_runtime/mod.rs
@@ -8,7 +8,7 @@ use inkwell::{
     context::Context,
     memory_buffer::MemoryBuffer,
     module::{Linkage, Module},
-    values::{AnyValue, BasicValue, InstructionOpcode, InstructionValue},
+    values::{AnyValue, BasicValue, FunctionValue, InstructionOpcode, InstructionValue},
 };
 use std::collections::HashMap;
 
@@ -18,6 +18,7 @@ pub(super) fn lower<'ctx>(
     context: &'ctx Context,
     module: &Module<'ctx>,
     target: CodegenTarget,
+    mut prepare_helper: impl FnMut(FunctionValue<'ctx>),
 ) -> Result<(), String> {
     let builder = context.create_builder();
     let mut helpers = HashMap::new();
@@ -54,6 +55,10 @@ pub(super) fn lower<'ctx>(
                 module.link_in_module(helper).map_err(|e| e.to_string())?;
                 let function = module.get_function(&name).expect("linked arithmetic helper");
                 function.set_linkage(Linkage::Private);
+                // Helpers are created after ordinary functions receive their
+                // code-generation attributes. They obey the same target and
+                // freestanding contract, including interrupt-safe stack use.
+                prepare_helper(function);
                 helpers.insert(key.clone(), function);
                 function
             };
@@ -151,7 +156,7 @@ mod tests {
             b"define <16 x i16> @vector(<16 x i16> %a) { %result = udiv <16 x i16> %a, splat (i16 251)\n ret <16 x i16> %result }",
             "vector-runtime-regression",
         )).unwrap();
-        lower(&context, &module, CodegenTarget::FreeBsdX86_64).unwrap();
+        lower(&context, &module, CodegenTarget::FreeBsdX86_64, |_| {}).unwrap();
         let ir = module.print_to_string().to_string();
         assert!(ir.contains("udiv <16 x i16>"));
         assert!(!ir.contains("__wave.runtime."));
diff --git a/llvm/src/codegen/ir.rs b/llvm/src/codegen/ir.rs
index f0eed73d..4b98b19d 100644
--- a/llvm/src/codegen/ir.rs
+++ b/llvm/src/codegen/ir.rs
@@ -1382,8 +1382,17 @@ fn build_module(
         codegen_trace("skip optimization passes");
     }
 
-    super::arithmetic_runtime::lower(context, module, abi_target)
-        .map_err(|e| CodegenError::new(CodegenPhase::Lowering, "lower arithmetic runtime", e))?;
+    super::arithmetic_runtime::lower(context, module, abi_target, |function| {
+        apply_function_codegen_attrs(
+            context,
+            function,
+            disable_red_zone,
+            abi_target,
+            cpu,
+            features,
+        );
+    })
+    .map_err(|e| CodegenError::new(CodegenPhase::Lowering, "lower arithmetic runtime", e))?;
 
     codegen_trace("finish module");
     Ok(GeneratedModule { module, target_machine: tm })
diff --git a/llvm/src/statement/control.rs b/llvm/src/statement/control.rs
index 36c9523c..50b7754f 100644
--- a/llvm/src/statement/control.rs
+++ b/llvm/src/statement/control.rs
@@ -1004,6 +1004,17 @@ pub(super) fn gen_return_ir<'ctx>(
                 extern_c_info,
             );
 
+            // Array expressions retain their storage address for indexing and
+            // pointer uses. A value return needs the aggregate itself, just as
+            // an array literal or an array argument already does.
+            if let (
+                BasicValueEnum::PointerValue(address),
+                inkwell::types::BasicTypeEnum::ArrayType(array),
+            ) = (v, ret_ty)
+            {
+                v = builder.build_load(array, address, "ret_array").unwrap();
+            }
+
             if v.get_type() != ret_ty {
                 v = coerce_basic_value(
                     context,
diff --git a/tests/cases/shared/test140.wave b/tests/cases/shared/test140.wave
new file mode 100644
index 00000000..9320da84
--- /dev/null
+++ b/tests/cases/shared/test140.wave
@@ -0,0 +1,58 @@
+// wave-test: mode=run
+// #913: truthiness checks an untyped integer's value before narrowing.
+const NONZERO: bool = 4294967296 as bool;
+const ZERO: bool = 0 as bool;
+
+fun main() -> i32 {
+    if (!NONZERO || ZERO) {
+        return 1;
+    }
+    if (!(4294967296 as bool) || !4294967296) {
+        return 2;
+    }
+    var entered: i32 = 0;
+    if ((4294967296)) {
+        entered += 1;
+    }
+    if (-4294967296) {
+        entered += 1;
+    }
+    if (18446744073709551616) {
+        entered += 1;
+    }
+    if (340282366920938463463374607431768211455) {
+        entered += 1;
+    }
+    while (4294967296) {
+        entered += 1;
+        break;
+    }
+    for (var i: i32 = 0; 4294967296; i += 1) {
+        entered += 1;
+        break;
+    }
+    if (true && 4294967296) {
+        entered += 1;
+    }
+    if (false || 4294967296) {
+        entered += 1;
+    }
+    if (entered != 8) {
+        return 3;
+    }
+    if (0 || !0 || 4294967296) {
+        entered += 1;
+    }
+    // A typed cast still discards high bits before the bool conversion.
+    if (4294967296 as i32) {
+        return 4;
+    }
+    // The invalid shift stays unexecuted because the left literal is nonzero.
+    if (!(4294967296 || ((1 as i32) << 32))) {
+        return 5;
+    }
+    if (entered != 9) {
+        return 6;
+    }
+    return 0;
+}
diff --git a/tests/cases/shared/test141.wave b/tests/cases/shared/test141.wave
new file mode 100644
index 00000000..60d9185e
--- /dev/null
+++ b/tests/cases/shared/test141.wave
@@ -0,0 +1,43 @@
+// wave-test: mode=run
+// #914: array returns copy values rather than leaking their local address.
+fun local() -> array<u8, 4> {
+    var bytes: array<u8, 4> = [7, 8, 9, 10];
+    return (bytes);
+}
+
+fun identity(bytes: array<u8, 4>) -> array<u8, 4> {
+    bytes[0] = 11;
+    return bytes;
+}
+
+fun literal() -> array<u8, 4> {
+    return [3, 4, 5, 6];
+}
+
+fun matrix() -> array<array<i32, 2>, 2> {
+    var cells: array<array<i32, 2>, 2> = [[1, 2], [3, 4]];
+    return cells;
+}
+
+fun empty() -> array<u8, 0> {
+    var bytes: array<u8, 0> = [];
+    return bytes;
+}
+
+fun main() -> i32 {
+    var a: array<u8, 4> = local();
+    var b: array<u8, 4> = identity(a);
+    var c: array<u8, 4> = literal();
+    if (a[0] != 7 || a[3] != 10 || b[0] != 11 || b[3] != 10) {
+        return 1;
+    }
+    if (c[0] != 3 || c[3] != 6) {
+        return 2;
+    }
+    var cells: array<array<i32, 2>, 2> = matrix();
+    if (cells[0][0] != 1 || cells[1][1] != 4) {
+        return 3;
+    }
+    var zero: array<u8, 0> = empty();
+    return 0;
+}
diff --git a/tests/codegen_regressions.rs b/tests/codegen_regressions.rs
index 955bfc5f..a911bd41 100644
--- a/tests/codegen_regressions.rs
+++ b/tests/codegen_regressions.rs
@@ -134,6 +134,19 @@ fn contextual_float_signedness_executes_at_o0_and_o2() {
     assert!(ir.contains("fptosi double"), "{ir}");
 }
 
+#[test]
+fn untyped_integer_truthiness_preserves_nonzero_values_at_o0_and_o2() {
+    run_shared_case_at_both_optimization_levels("test140");
+}
+
+#[test]
+fn fixed_array_returns_preserve_caller_observed_values_at_o0_and_o2() {
+    let ir = run_shared_case_at_both_optimization_levels("test141");
+    assert!(ir.contains("ret_array = load [4 x i8]"), "{ir}");
+    assert!(ir.contains("load [2 x [2 x i32]]"), "{ir}");
+    assert!(ir.contains("load [0 x i8]"), "{ir}");
+}
+
 #[test]
 fn compact_variants_preserve_constants_statics_and_nested_payloads() {
     run_shared_case_at_both_optimization_levels("test126");
@@ -4170,6 +4183,64 @@ fun leaf(a: i64, b: i64, c: i64, d: i64, e: i64) -> i64 {
     );
 }
 
+#[test]
+fn arithmetic_helpers_keep_target_and_freestanding_function_attributes() {
+    let dir = temp_case_dir("runtime-function-attributes");
+    let source = write_wave(
+        &dir,
+        "runtime.wave",
+        r#"
+fun divide(a: u128, b: u128) -> u128 { return a / b; }
+fun remainder(a: u128, b: u128) -> u128 { return a % b; }
+fun convert(a: u128) -> f64 { return a as f64; }
+"#,
+    );
+    for (mode, target, freestanding) in [
+        ("bare", "x86_64-unknown-none-elf", false),
+        ("explicit", "x86_64-unknown-linux-gnu", true),
+        ("hosted", "x86_64-unknown-linux-gnu", false),
+    ] {
+        for optimization in ["-O0", "-O2"] {
+            let out = dir.join(mode).join(optimization);
+            let mut command = wavec_command();
+            command
+                .arg("build")
+                .arg(&source)
+                .arg("--target")
+                .arg(target)
+                .args(["--cpu=x86-64-v3", "--features=+avx2", optimization, "--emit=ir,obj"])
+                .arg("--out-dir")
+                .arg(&out);
+            if freestanding {
+                command.arg("--freestanding");
+            }
+            let output = command.output().unwrap();
+            assert!(output.status.success(), "{}", String::from_utf8_lossy(&output.stderr));
+            let ir = fs::read_to_string(out.join("runtime.ll")).unwrap();
+            let helpers: Vec<_> =
+                ir.lines().filter(|line| line.starts_with("define private")).collect();
+            assert_eq!(helpers.len(), 3, "{ir}");
+            for helper in helpers {
+                let group = helper.split_whitespace().find(|word| word.starts_with('#')).unwrap();
+                let prefix = format!("attributes {group} =");
+                let attributes = ir.lines().find(|line| line.starts_with(&prefix)).unwrap();
+                assert!(
+                    attributes.contains("\"target-cpu\"=\"x86-64-v3\""),
+                    "{helper}: {attributes}"
+                );
+                assert!(
+                    attributes.contains("\"target-features\"=\"+avx2\""),
+                    "{helper}: {attributes}"
+                );
+                assert_eq!(attributes.contains("noredzone"), mode != "hosted", "{attributes}");
+                if mode != "hosted" {
+                    assert!(attributes.contains("nounwind"), "{attributes}");
+                }
+            }
+        }
+    }
+}
+
 #[test]
 fn inline_asm_requires_explicit_stack_contract() {
     let dir = temp_case_dir("asm-stack-contract");
diff --git a/tests/whale_backend.rs b/tests/whale_backend.rs
index ca531200..b85d0b6f 100644
--- a/tests/whale_backend.rs
+++ b/tests/whale_backend.rs
@@ -140,6 +140,24 @@ fun main() -> i32 {
     }
 }
 
+#[test]
+fn untyped_integer_condition_literals_retain_their_values_in_whale_ir() {
+    let case = Case::new(
+        "literal-truthiness",
+        r#"
+fun main() -> i32 {
+    if (4294967296 as i32) { return 1; }
+    if (4294967296 && -4294967296) { return 0; }
+    return 2;
+}
+"#,
+    );
+    let ir = case.ir();
+    assert!(ir.contains("const i64 4294967296"), "{ir}");
+    assert!(ir.contains("icmp ne i64"), "{ir}");
+    assert!(case.run(&["--whale", "check", "main.wave"]).status.success());
+}
+
 #[test]
 fn void_calls_keep_effects_through_grouping_and_void_returns() {
     let case = Case::new(
diff --git a/whale/src/codegen/tests/oracle.rs b/whale/src/codegen/tests/oracle.rs
index 389a252b..6fbecb1c 100644
--- a/whale/src/codegen/tests/oracle.rs
+++ b/whale/src/codegen/tests/oracle.rs
@@ -195,6 +195,41 @@ fn numeric_condition_truthiness_executes_without_reinferring_hir_types() {
     assert_eq!(run(&ir, &[ConstValue::I(-3)]).unwrap().value, Some(ConstValue::I(0)));
 }
 
+#[test]
+fn integer_literal_truthiness_checks_the_value_before_any_narrowing() {
+    for literal in [
+        "0",
+        "1",
+        "2147483648",
+        "4294967296",
+        "-4294967296",
+        "18446744073709551616",
+        "170141183460469231731687303715884105727",
+    ] {
+        let nonzero = literal != "0";
+        for expression in [
+            literal.to_owned(),
+            format!("({literal})"),
+            format!("{literal} as bool"),
+            format!("true && {literal}"),
+            format!("false || {literal}"),
+            format!("!{literal}"),
+        ] {
+            let ir = module(&format!(
+                "fun probe() -> i32 {{ if ({expression}) {{ return 7; }} return 0; }}"
+            ));
+            let expected = if expression.starts_with('!') { !nonzero } else { nonzero };
+            assert_eq!(
+                run(&ir, &[]).unwrap().value,
+                Some(ConstValue::I(if expected { 7 } else { 0 })),
+                "{expression}"
+            );
+        }
+    }
+    let ir = module("fun probe() -> bool { return (4294967296 as i32) as bool; }");
+    assert_eq!(run(&ir, &[]).unwrap().value, Some(ConstValue::Bool(false)));
+}
+
 #[test]
 fn budgets_unsupported_operations_and_traps_have_distinct_outcomes() {
     let ir = module(