| use rustc::mir; |
| use rustc::ty::{self, Ty, layout::{TyLayout, LayoutOf}}; |
| use syntax::ast::FloatTy; |
| use rustc_apfloat::Float; |
| use rustc::mir::interpret::{InterpResult, Scalar}; |
| |
| use super::{InterpCx, PlaceTy, Immediate, Machine, ImmTy}; |
| |
| |
| impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { |
| /// Applies the binary operation `op` to the two operands and writes a tuple of the result |
| /// and a boolean signifying the potential overflow to the destination. |
| pub fn binop_with_overflow( |
| &mut self, |
| op: mir::BinOp, |
| left: ImmTy<'tcx, M::PointerTag>, |
| right: ImmTy<'tcx, M::PointerTag>, |
| dest: PlaceTy<'tcx, M::PointerTag>, |
| ) -> InterpResult<'tcx> { |
| let (val, overflowed, ty) = self.overflowing_binary_op(op, left, right)?; |
| debug_assert_eq!( |
| self.tcx.intern_tup(&[ty, self.tcx.types.bool]), |
| dest.layout.ty, |
| "type mismatch for result of {:?}", op, |
| ); |
| let val = Immediate::ScalarPair(val.into(), Scalar::from_bool(overflowed).into()); |
| self.write_immediate(val, dest) |
| } |
| |
| /// Applies the binary operation `op` to the arguments and writes the result to the |
| /// destination. |
| pub fn binop_ignore_overflow( |
| &mut self, |
| op: mir::BinOp, |
| left: ImmTy<'tcx, M::PointerTag>, |
| right: ImmTy<'tcx, M::PointerTag>, |
| dest: PlaceTy<'tcx, M::PointerTag>, |
| ) -> InterpResult<'tcx> { |
| let (val, _overflowed, ty) = self.overflowing_binary_op(op, left, right)?; |
| assert_eq!(ty, dest.layout.ty, "type mismatch for result of {:?}", op); |
| self.write_scalar(val, dest) |
| } |
| } |
| |
| impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { |
| fn binary_char_op( |
| &self, |
| bin_op: mir::BinOp, |
| l: char, |
| r: char, |
| ) -> (Scalar<M::PointerTag>, bool, Ty<'tcx>) { |
| use rustc::mir::BinOp::*; |
| |
| let res = match bin_op { |
| Eq => l == r, |
| Ne => l != r, |
| Lt => l < r, |
| Le => l <= r, |
| Gt => l > r, |
| Ge => l >= r, |
| _ => bug!("Invalid operation on char: {:?}", bin_op), |
| }; |
| return (Scalar::from_bool(res), false, self.tcx.types.bool); |
| } |
| |
| fn binary_bool_op( |
| &self, |
| bin_op: mir::BinOp, |
| l: bool, |
| r: bool, |
| ) -> (Scalar<M::PointerTag>, bool, Ty<'tcx>) { |
| use rustc::mir::BinOp::*; |
| |
| let res = match bin_op { |
| Eq => l == r, |
| Ne => l != r, |
| Lt => l < r, |
| Le => l <= r, |
| Gt => l > r, |
| Ge => l >= r, |
| BitAnd => l & r, |
| BitOr => l | r, |
| BitXor => l ^ r, |
| _ => bug!("Invalid operation on bool: {:?}", bin_op), |
| }; |
| return (Scalar::from_bool(res), false, self.tcx.types.bool); |
| } |
| |
| fn binary_float_op<F: Float + Into<Scalar<M::PointerTag>>>( |
| &self, |
| bin_op: mir::BinOp, |
| ty: Ty<'tcx>, |
| l: F, |
| r: F, |
| ) -> (Scalar<M::PointerTag>, bool, Ty<'tcx>) { |
| use rustc::mir::BinOp::*; |
| |
| let (val, ty) = match bin_op { |
| Eq => (Scalar::from_bool(l == r), self.tcx.types.bool), |
| Ne => (Scalar::from_bool(l != r), self.tcx.types.bool), |
| Lt => (Scalar::from_bool(l < r), self.tcx.types.bool), |
| Le => (Scalar::from_bool(l <= r), self.tcx.types.bool), |
| Gt => (Scalar::from_bool(l > r), self.tcx.types.bool), |
| Ge => (Scalar::from_bool(l >= r), self.tcx.types.bool), |
| Add => ((l + r).value.into(), ty), |
| Sub => ((l - r).value.into(), ty), |
| Mul => ((l * r).value.into(), ty), |
| Div => ((l / r).value.into(), ty), |
| Rem => ((l % r).value.into(), ty), |
| _ => bug!("invalid float op: `{:?}`", bin_op), |
| }; |
| return (val, false, ty); |
| } |
| |
| fn binary_int_op( |
| &self, |
| bin_op: mir::BinOp, |
| // passing in raw bits |
| l: u128, |
| left_layout: TyLayout<'tcx>, |
| r: u128, |
| right_layout: TyLayout<'tcx>, |
| ) -> InterpResult<'tcx, (Scalar<M::PointerTag>, bool, Ty<'tcx>)> { |
| use rustc::mir::BinOp::*; |
| |
| // Shift ops can have an RHS with a different numeric type. |
| if bin_op == Shl || bin_op == Shr { |
| let signed = left_layout.abi.is_signed(); |
| let mut oflo = (r as u32 as u128) != r; |
| let mut r = r as u32; |
| let size = left_layout.size; |
| oflo |= r >= size.bits() as u32; |
| if oflo { |
| r %= size.bits() as u32; |
| } |
| let result = if signed { |
| let l = self.sign_extend(l, left_layout) as i128; |
| let result = match bin_op { |
| Shl => l << r, |
| Shr => l >> r, |
| _ => bug!("it has already been checked that this is a shift op"), |
| }; |
| result as u128 |
| } else { |
| match bin_op { |
| Shl => l << r, |
| Shr => l >> r, |
| _ => bug!("it has already been checked that this is a shift op"), |
| } |
| }; |
| let truncated = self.truncate(result, left_layout); |
| return Ok((Scalar::from_uint(truncated, size), oflo, left_layout.ty)); |
| } |
| |
| // For the remaining ops, the types must be the same on both sides |
| if left_layout.ty != right_layout.ty { |
| bug!( |
| "invalid asymmetric binary op {:?}: {:?} ({:?}), {:?} ({:?})", |
| bin_op, |
| l, left_layout.ty, |
| r, right_layout.ty, |
| ) |
| } |
| |
| // Operations that need special treatment for signed integers |
| if left_layout.abi.is_signed() { |
| let op: Option<fn(&i128, &i128) -> bool> = match bin_op { |
| Lt => Some(i128::lt), |
| Le => Some(i128::le), |
| Gt => Some(i128::gt), |
| Ge => Some(i128::ge), |
| _ => None, |
| }; |
| if let Some(op) = op { |
| let l = self.sign_extend(l, left_layout) as i128; |
| let r = self.sign_extend(r, right_layout) as i128; |
| return Ok((Scalar::from_bool(op(&l, &r)), false, self.tcx.types.bool)); |
| } |
| let op: Option<fn(i128, i128) -> (i128, bool)> = match bin_op { |
| Div if r == 0 => throw_ub!(DivisionByZero), |
| Rem if r == 0 => throw_ub!(RemainderByZero), |
| Div => Some(i128::overflowing_div), |
| Rem => Some(i128::overflowing_rem), |
| Add => Some(i128::overflowing_add), |
| Sub => Some(i128::overflowing_sub), |
| Mul => Some(i128::overflowing_mul), |
| _ => None, |
| }; |
| if let Some(op) = op { |
| let l128 = self.sign_extend(l, left_layout) as i128; |
| let r = self.sign_extend(r, right_layout) as i128; |
| let size = left_layout.size; |
| match bin_op { |
| Rem | Div => { |
| // int_min / -1 |
| if r == -1 && l == (1 << (size.bits() - 1)) { |
| return Ok((Scalar::from_uint(l, size), true, left_layout.ty)); |
| } |
| }, |
| _ => {}, |
| } |
| trace!("{}, {}, {}", l, l128, r); |
| let (result, mut oflo) = op(l128, r); |
| trace!("{}, {}", result, oflo); |
| if !oflo && size.bits() != 128 { |
| let max = 1 << (size.bits() - 1); |
| oflo = result >= max || result < -max; |
| } |
| // this may be out-of-bounds for the result type, so we have to truncate ourselves |
| let result = result as u128; |
| let truncated = self.truncate(result, left_layout); |
| return Ok((Scalar::from_uint(truncated, size), oflo, left_layout.ty)); |
| } |
| } |
| |
| let size = left_layout.size; |
| |
| let (val, ty) = match bin_op { |
| Eq => (Scalar::from_bool(l == r), self.tcx.types.bool), |
| Ne => (Scalar::from_bool(l != r), self.tcx.types.bool), |
| |
| Lt => (Scalar::from_bool(l < r), self.tcx.types.bool), |
| Le => (Scalar::from_bool(l <= r), self.tcx.types.bool), |
| Gt => (Scalar::from_bool(l > r), self.tcx.types.bool), |
| Ge => (Scalar::from_bool(l >= r), self.tcx.types.bool), |
| |
| BitOr => (Scalar::from_uint(l | r, size), left_layout.ty), |
| BitAnd => (Scalar::from_uint(l & r, size), left_layout.ty), |
| BitXor => (Scalar::from_uint(l ^ r, size), left_layout.ty), |
| |
| Add | Sub | Mul | Rem | Div => { |
| debug_assert!(!left_layout.abi.is_signed()); |
| let op: fn(u128, u128) -> (u128, bool) = match bin_op { |
| Add => u128::overflowing_add, |
| Sub => u128::overflowing_sub, |
| Mul => u128::overflowing_mul, |
| Div if r == 0 => throw_ub!(DivisionByZero), |
| Rem if r == 0 => throw_ub!(RemainderByZero), |
| Div => u128::overflowing_div, |
| Rem => u128::overflowing_rem, |
| _ => bug!(), |
| }; |
| let (result, oflo) = op(l, r); |
| let truncated = self.truncate(result, left_layout); |
| return Ok(( |
| Scalar::from_uint(truncated, size), |
| oflo || truncated != result, |
| left_layout.ty, |
| )); |
| } |
| |
| _ => { |
| bug!( |
| "invalid binary op {:?}: {:?}, {:?} (both {:?})", |
| bin_op, |
| l, |
| r, |
| right_layout.ty, |
| ) |
| } |
| }; |
| |
| Ok((val, false, ty)) |
| } |
| |
| /// Returns the result of the specified operation, whether it overflowed, and |
| /// the result type. |
| pub fn overflowing_binary_op( |
| &self, |
| bin_op: mir::BinOp, |
| left: ImmTy<'tcx, M::PointerTag>, |
| right: ImmTy<'tcx, M::PointerTag>, |
| ) -> InterpResult<'tcx, (Scalar<M::PointerTag>, bool, Ty<'tcx>)> { |
| trace!("Running binary op {:?}: {:?} ({:?}), {:?} ({:?})", |
| bin_op, *left, left.layout.ty, *right, right.layout.ty); |
| |
| match left.layout.ty.kind { |
| ty::Char => { |
| assert_eq!(left.layout.ty, right.layout.ty); |
| let left = left.to_scalar()?; |
| let right = right.to_scalar()?; |
| Ok(self.binary_char_op(bin_op, left.to_char()?, right.to_char()?)) |
| } |
| ty::Bool => { |
| assert_eq!(left.layout.ty, right.layout.ty); |
| let left = left.to_scalar()?; |
| let right = right.to_scalar()?; |
| Ok(self.binary_bool_op(bin_op, left.to_bool()?, right.to_bool()?)) |
| } |
| ty::Float(fty) => { |
| assert_eq!(left.layout.ty, right.layout.ty); |
| let ty = left.layout.ty; |
| let left = left.to_scalar()?; |
| let right = right.to_scalar()?; |
| Ok(match fty { |
| FloatTy::F32 => |
| self.binary_float_op(bin_op, ty, left.to_f32()?, right.to_f32()?), |
| FloatTy::F64 => |
| self.binary_float_op(bin_op, ty, left.to_f64()?, right.to_f64()?), |
| }) |
| } |
| _ if left.layout.ty.is_integral() => { |
| // the RHS type can be different, e.g. for shifts -- but it has to be integral, too |
| assert!( |
| right.layout.ty.is_integral(), |
| "Unexpected types for BinOp: {:?} {:?} {:?}", |
| left.layout.ty, bin_op, right.layout.ty |
| ); |
| |
| let l = self.force_bits(left.to_scalar()?, left.layout.size)?; |
| let r = self.force_bits(right.to_scalar()?, right.layout.size)?; |
| self.binary_int_op(bin_op, l, left.layout, r, right.layout) |
| } |
| _ if left.layout.ty.is_any_ptr() => { |
| // The RHS type must be the same *or an integer type* (for `Offset`). |
| assert!( |
| right.layout.ty == left.layout.ty || right.layout.ty.is_integral(), |
| "Unexpected types for BinOp: {:?} {:?} {:?}", |
| left.layout.ty, bin_op, right.layout.ty |
| ); |
| |
| M::binary_ptr_op(self, bin_op, left, right) |
| } |
| _ => bug!("Invalid MIR: bad LHS type for binop: {:?}", left.layout.ty), |
| } |
| } |
| |
| /// Typed version of `checked_binary_op`, returning an `ImmTy`. Also ignores overflows. |
| #[inline] |
| pub fn binary_op( |
| &self, |
| bin_op: mir::BinOp, |
| left: ImmTy<'tcx, M::PointerTag>, |
| right: ImmTy<'tcx, M::PointerTag>, |
| ) -> InterpResult<'tcx, ImmTy<'tcx, M::PointerTag>> { |
| let (val, _overflow, ty) = self.overflowing_binary_op(bin_op, left, right)?; |
| Ok(ImmTy::from_scalar(val, self.layout_of(ty)?)) |
| } |
| |
| pub fn unary_op( |
| &self, |
| un_op: mir::UnOp, |
| val: ImmTy<'tcx, M::PointerTag>, |
| ) -> InterpResult<'tcx, ImmTy<'tcx, M::PointerTag>> { |
| use rustc::mir::UnOp::*; |
| |
| let layout = val.layout; |
| let val = val.to_scalar()?; |
| trace!("Running unary op {:?}: {:?} ({:?})", un_op, val, layout.ty); |
| |
| match layout.ty.kind { |
| ty::Bool => { |
| let val = val.to_bool()?; |
| let res = match un_op { |
| Not => !val, |
| _ => bug!("Invalid bool op {:?}", un_op) |
| }; |
| Ok(ImmTy::from_scalar(Scalar::from_bool(res), self.layout_of(self.tcx.types.bool)?)) |
| } |
| ty::Float(fty) => { |
| let res = match (un_op, fty) { |
| (Neg, FloatTy::F32) => Scalar::from_f32(-val.to_f32()?), |
| (Neg, FloatTy::F64) => Scalar::from_f64(-val.to_f64()?), |
| _ => bug!("Invalid float op {:?}", un_op) |
| }; |
| Ok(ImmTy::from_scalar(res, layout)) |
| } |
| _ => { |
| assert!(layout.ty.is_integral()); |
| let val = self.force_bits(val, layout.size)?; |
| let res = match un_op { |
| Not => !val, |
| Neg => { |
| assert!(layout.abi.is_signed()); |
| (-(val as i128)) as u128 |
| } |
| }; |
| // res needs tuncating |
| Ok(ImmTy::from_uint(self.truncate(res, layout), layout)) |
| } |
| } |
| } |
| } |
