diff options
| -rw-r--r-- | compiler/rustc_codegen_ssa/src/mir/rvalue.rs | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/compiler/rustc_codegen_ssa/src/mir/rvalue.rs b/compiler/rustc_codegen_ssa/src/mir/rvalue.rs index 7c8d23a3329..95bc0b30bea 100644 --- a/compiler/rustc_codegen_ssa/src/mir/rvalue.rs +++ b/compiler/rustc_codegen_ssa/src/mir/rvalue.rs @@ -656,6 +656,9 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { // with #[rustc_inherit_overflow_checks] and inlined from // another crate (mostly core::num generic/#[inline] fns), // while the current crate doesn't use overflow checks. + // + // As an optimization, we emit an unchecked binop when overflow checks are disabled, + // as the overflow flag would be ignored anyway. if !bx.cx().check_overflow() { let val = self.codegen_scalar_binop(bx, op, lhs, rhs, input_ty); return OperandValue::Pair(val, bx.cx().const_bool(false)); |