diff options
| -rw-r--r-- | src/librustc_mir/interpret/intrinsics.rs | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/src/librustc_mir/interpret/intrinsics.rs b/src/librustc_mir/interpret/intrinsics.rs index f85da760ada..33070f7e656 100644 --- a/src/librustc_mir/interpret/intrinsics.rs +++ b/src/librustc_mir/interpret/intrinsics.rs @@ -410,8 +410,9 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { ) -> 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(); @@ -421,6 +422,7 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { 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) } } |