) -> InterpResult<'tcx> {
// Performs an exact division, resulting in undefined behavior where
// `x % y != 0` or `y == 0` or `x == T::min_value() && y == -1`.
- // First, check x % y != 0.
- if self.binary_op(BinOp::Rem, a, b)?.to_bits()? != 0 {
+ // First, check x % y != 0 (or if that computation overflows).
+ let (res, overflow, _ty) = self.overflowing_binary_op(BinOp::Rem, a, b)?;
+ if overflow || res.to_bits(a.layout.size)? != 0 {
// Then, check if `b` is -1, which is the "min_value / -1" case.
let minus1 = Scalar::from_int(-1, dest.layout.size);
let b_scalar = b.to_scalar().unwrap();
throw_ub_format!("exact_div: {} cannot be divided by {} without remainder", a, b,)
}
}
+ // `Rem` says this is all right, so we can let `Div` do its job.
self.binop_ignore_overflow(BinOp::Div, a, b, dest)
}
}