| //! Definition of [`CValue`] and [`CPlace`] | 
 |  | 
 | use cranelift_codegen::entity::EntityRef; | 
 | use cranelift_codegen::ir::immediates::Offset32; | 
 | use cranelift_frontend::Variable; | 
 | use rustc_middle::ty::FnSig; | 
 | use rustc_middle::ty::layout::HasTypingEnv; | 
 |  | 
 | use crate::prelude::*; | 
 |  | 
 | fn codegen_field<'tcx>( | 
 |     fx: &mut FunctionCx<'_, '_, 'tcx>, | 
 |     base: Pointer, | 
 |     extra: Option<Value>, | 
 |     layout: TyAndLayout<'tcx>, | 
 |     field: FieldIdx, | 
 | ) -> (Pointer, TyAndLayout<'tcx>) { | 
 |     let field_offset = layout.fields.offset(field.index()); | 
 |     let field_layout = layout.field(&*fx, field.index()); | 
 |  | 
 |     let simple = |fx: &mut FunctionCx<'_, '_, '_>| { | 
 |         (base.offset_i64(fx, i64::try_from(field_offset.bytes()).unwrap()), field_layout) | 
 |     }; | 
 |  | 
 |     if field_layout.is_sized() { | 
 |         return simple(fx); | 
 |     } | 
 |     match field_layout.ty.kind() { | 
 |         ty::Slice(..) | ty::Str => simple(fx), | 
 |         _ => { | 
 |             let unaligned_offset = field_offset.bytes(); | 
 |  | 
 |             // Get the alignment of the field | 
 |             let (_, mut unsized_align) = crate::unsize::size_and_align_of(fx, field_layout, extra); | 
 |  | 
 |             // For packed types, we need to cap alignment. | 
 |             if let ty::Adt(def, _) = layout.ty.kind() { | 
 |                 if let Some(packed) = def.repr().pack { | 
 |                     let packed = fx.bcx.ins().iconst(fx.pointer_type, packed.bytes() as i64); | 
 |                     let cmp = fx.bcx.ins().icmp(IntCC::UnsignedLessThan, unsized_align, packed); | 
 |                     unsized_align = fx.bcx.ins().select(cmp, unsized_align, packed); | 
 |                 } | 
 |             } | 
 |  | 
 |             // Bump the unaligned offset up to the appropriate alignment | 
 |             let one = fx.bcx.ins().iconst(fx.pointer_type, 1); | 
 |             let align_sub_1 = fx.bcx.ins().isub(unsized_align, one); | 
 |             let and_lhs = fx.bcx.ins().iadd_imm(align_sub_1, unaligned_offset as i64); | 
 |             let zero = fx.bcx.ins().iconst(fx.pointer_type, 0); | 
 |             let and_rhs = fx.bcx.ins().isub(zero, unsized_align); | 
 |             let offset = fx.bcx.ins().band(and_lhs, and_rhs); | 
 |  | 
 |             (base.offset_value(fx, offset), field_layout) | 
 |         } | 
 |     } | 
 | } | 
 |  | 
 | fn scalar_pair_calculate_b_offset(tcx: TyCtxt<'_>, a_scalar: Scalar, b_scalar: Scalar) -> Offset32 { | 
 |     let b_offset = a_scalar.size(&tcx).align_to(b_scalar.align(&tcx).abi); | 
 |     Offset32::new(b_offset.bytes().try_into().unwrap()) | 
 | } | 
 |  | 
 | /// A read-only value | 
 | #[derive(Debug, Copy, Clone)] | 
 | pub(crate) struct CValue<'tcx>(CValueInner, TyAndLayout<'tcx>); | 
 |  | 
 | #[derive(Debug, Copy, Clone)] | 
 | enum CValueInner { | 
 |     ByRef(Pointer, Option<Value>), | 
 |     ByVal(Value), | 
 |     ByValPair(Value, Value), | 
 | } | 
 |  | 
 | impl<'tcx> CValue<'tcx> { | 
 |     pub(crate) fn by_ref(ptr: Pointer, layout: TyAndLayout<'tcx>) -> CValue<'tcx> { | 
 |         CValue(CValueInner::ByRef(ptr, None), layout) | 
 |     } | 
 |  | 
 |     pub(crate) fn by_ref_unsized( | 
 |         ptr: Pointer, | 
 |         meta: Value, | 
 |         layout: TyAndLayout<'tcx>, | 
 |     ) -> CValue<'tcx> { | 
 |         CValue(CValueInner::ByRef(ptr, Some(meta)), layout) | 
 |     } | 
 |  | 
 |     pub(crate) fn by_val(value: Value, layout: TyAndLayout<'tcx>) -> CValue<'tcx> { | 
 |         CValue(CValueInner::ByVal(value), layout) | 
 |     } | 
 |  | 
 |     pub(crate) fn by_val_pair( | 
 |         value: Value, | 
 |         extra: Value, | 
 |         layout: TyAndLayout<'tcx>, | 
 |     ) -> CValue<'tcx> { | 
 |         CValue(CValueInner::ByValPair(value, extra), layout) | 
 |     } | 
 |  | 
 |     /// Create an instance of a ZST | 
 |     /// | 
 |     /// The is represented by a dangling pointer of suitable alignment. | 
 |     pub(crate) fn zst(layout: TyAndLayout<'tcx>) -> CValue<'tcx> { | 
 |         assert!(layout.is_zst()); | 
 |         CValue::by_ref(crate::Pointer::dangling(layout.align.abi), layout) | 
 |     } | 
 |  | 
 |     pub(crate) fn layout(&self) -> TyAndLayout<'tcx> { | 
 |         self.1 | 
 |     } | 
 |  | 
 |     // FIXME remove | 
 |     pub(crate) fn force_stack(self, fx: &mut FunctionCx<'_, '_, 'tcx>) -> (Pointer, Option<Value>) { | 
 |         let layout = self.1; | 
 |         match self.0 { | 
 |             CValueInner::ByRef(ptr, meta) => (ptr, meta), | 
 |             CValueInner::ByVal(_) | CValueInner::ByValPair(_, _) => { | 
 |                 let cplace = CPlace::new_stack_slot(fx, layout); | 
 |                 cplace.write_cvalue(fx, self); | 
 |                 (cplace.to_ptr(), None) | 
 |             } | 
 |         } | 
 |     } | 
 |  | 
 |     pub(crate) fn try_to_ptr(self) -> Option<(Pointer, Option<Value>)> { | 
 |         match self.0 { | 
 |             CValueInner::ByRef(ptr, meta) => Some((ptr, meta)), | 
 |             CValueInner::ByVal(_) | CValueInner::ByValPair(_, _) => None, | 
 |         } | 
 |     } | 
 |  | 
 |     /// Load a value with layout.backend_repr of scalar | 
 |     #[track_caller] | 
 |     pub(crate) fn load_scalar(self, fx: &mut FunctionCx<'_, '_, 'tcx>) -> Value { | 
 |         let layout = self.1; | 
 |         match self.0 { | 
 |             CValueInner::ByRef(ptr, None) => { | 
 |                 let clif_ty = match layout.backend_repr { | 
 |                     BackendRepr::Scalar(scalar) => scalar_to_clif_type(fx.tcx, scalar), | 
 |                     BackendRepr::SimdVector { element, count } => { | 
 |                         scalar_to_clif_type(fx.tcx, element) | 
 |                             .by(u32::try_from(count).unwrap()) | 
 |                             .unwrap() | 
 |                     } | 
 |                     _ => unreachable!("{:?}", layout.ty), | 
 |                 }; | 
 |                 let mut flags = MemFlags::new(); | 
 |                 flags.set_notrap(); | 
 |                 ptr.load(fx, clif_ty, flags) | 
 |             } | 
 |             CValueInner::ByVal(value) => value, | 
 |             CValueInner::ByRef(_, Some(_)) => bug!("load_scalar for unsized value not allowed"), | 
 |             CValueInner::ByValPair(_, _) => bug!("Please use load_scalar_pair for ByValPair"), | 
 |         } | 
 |     } | 
 |  | 
 |     /// Load a value pair with layout.backend_repr of scalar pair | 
 |     #[track_caller] | 
 |     pub(crate) fn load_scalar_pair(self, fx: &mut FunctionCx<'_, '_, 'tcx>) -> (Value, Value) { | 
 |         let layout = self.1; | 
 |         match self.0 { | 
 |             CValueInner::ByRef(ptr, None) => { | 
 |                 let (a_scalar, b_scalar) = match layout.backend_repr { | 
 |                     BackendRepr::ScalarPair(a, b) => (a, b), | 
 |                     _ => unreachable!("load_scalar_pair({:?})", self), | 
 |                 }; | 
 |                 let b_offset = scalar_pair_calculate_b_offset(fx.tcx, a_scalar, b_scalar); | 
 |                 let clif_ty1 = scalar_to_clif_type(fx.tcx, a_scalar); | 
 |                 let clif_ty2 = scalar_to_clif_type(fx.tcx, b_scalar); | 
 |                 let mut flags = MemFlags::new(); | 
 |                 flags.set_notrap(); | 
 |                 let val1 = ptr.load(fx, clif_ty1, flags); | 
 |                 let val2 = ptr.offset(fx, b_offset).load(fx, clif_ty2, flags); | 
 |                 (val1, val2) | 
 |             } | 
 |             CValueInner::ByRef(_, Some(_)) => { | 
 |                 bug!("load_scalar_pair for unsized value not allowed") | 
 |             } | 
 |             CValueInner::ByVal(_) => bug!("Please use load_scalar for ByVal"), | 
 |             CValueInner::ByValPair(val1, val2) => (val1, val2), | 
 |         } | 
 |     } | 
 |  | 
 |     pub(crate) fn value_field( | 
 |         self, | 
 |         fx: &mut FunctionCx<'_, '_, 'tcx>, | 
 |         field: FieldIdx, | 
 |     ) -> CValue<'tcx> { | 
 |         let layout = self.1; | 
 |         match self.0 { | 
 |             CValueInner::ByVal(_) => unreachable!(), | 
 |             CValueInner::ByValPair(val1, val2) => match layout.backend_repr { | 
 |                 BackendRepr::ScalarPair(_, _) => { | 
 |                     let val = match field.as_u32() { | 
 |                         0 => val1, | 
 |                         1 => val2, | 
 |                         _ => bug!("field should be 0 or 1"), | 
 |                     }; | 
 |                     let field_layout = layout.field(&*fx, usize::from(field)); | 
 |                     CValue::by_val(val, field_layout) | 
 |                 } | 
 |                 _ => unreachable!("value_field for ByValPair with abi {:?}", layout.backend_repr), | 
 |             }, | 
 |             CValueInner::ByRef(ptr, None) => { | 
 |                 let (field_ptr, field_layout) = codegen_field(fx, ptr, None, layout, field); | 
 |                 CValue::by_ref(field_ptr, field_layout) | 
 |             } | 
 |             CValueInner::ByRef(_, Some(_)) => todo!(), | 
 |         } | 
 |     } | 
 |  | 
 |     /// Like [`CValue::value_field`] except handling ADTs containing a single array field in a way | 
 |     /// such that you can access individual lanes. | 
 |     pub(crate) fn value_lane( | 
 |         self, | 
 |         fx: &mut FunctionCx<'_, '_, 'tcx>, | 
 |         lane_idx: u64, | 
 |     ) -> CValue<'tcx> { | 
 |         let layout = self.1; | 
 |         assert!(layout.ty.is_simd()); | 
 |         let (lane_count, lane_ty) = layout.ty.simd_size_and_type(fx.tcx); | 
 |         let lane_layout = fx.layout_of(lane_ty); | 
 |         assert!(lane_idx < lane_count); | 
 |  | 
 |         match self.0 { | 
 |             CValueInner::ByVal(_) | CValueInner::ByValPair(_, _) => unreachable!(), | 
 |             CValueInner::ByRef(ptr, None) => { | 
 |                 let field_offset = lane_layout.size * lane_idx; | 
 |                 let field_ptr = ptr.offset_i64(fx, i64::try_from(field_offset.bytes()).unwrap()); | 
 |                 CValue::by_ref(field_ptr, lane_layout) | 
 |             } | 
 |             CValueInner::ByRef(_, Some(_)) => unreachable!(), | 
 |         } | 
 |     } | 
 |  | 
 |     /// Like [`CValue::value_field`] except using the passed type as lane type instead of the one | 
 |     /// specified by the vector type. | 
 |     pub(crate) fn value_typed_lane( | 
 |         self, | 
 |         fx: &mut FunctionCx<'_, '_, 'tcx>, | 
 |         lane_ty: Ty<'tcx>, | 
 |         lane_idx: u64, | 
 |     ) -> CValue<'tcx> { | 
 |         let layout = self.1; | 
 |         assert!(layout.ty.is_simd()); | 
 |         let (orig_lane_count, orig_lane_ty) = layout.ty.simd_size_and_type(fx.tcx); | 
 |         let lane_layout = fx.layout_of(lane_ty); | 
 |         assert!( | 
 |             (lane_idx + 1) * lane_layout.size <= orig_lane_count * fx.layout_of(orig_lane_ty).size | 
 |         ); | 
 |  | 
 |         match self.0 { | 
 |             CValueInner::ByVal(_) | CValueInner::ByValPair(_, _) => unreachable!(), | 
 |             CValueInner::ByRef(ptr, None) => { | 
 |                 let field_offset = lane_layout.size * lane_idx; | 
 |                 let field_ptr = ptr.offset_i64(fx, i64::try_from(field_offset.bytes()).unwrap()); | 
 |                 CValue::by_ref(field_ptr, lane_layout) | 
 |             } | 
 |             CValueInner::ByRef(_, Some(_)) => unreachable!(), | 
 |         } | 
 |     } | 
 |  | 
 |     /// Like [`CValue::value_lane`] except allowing a dynamically calculated lane index. | 
 |     pub(crate) fn value_lane_dyn( | 
 |         self, | 
 |         fx: &mut FunctionCx<'_, '_, 'tcx>, | 
 |         lane_idx: Value, | 
 |     ) -> CValue<'tcx> { | 
 |         let layout = self.1; | 
 |         assert!(layout.ty.is_simd()); | 
 |         let (_lane_count, lane_ty) = layout.ty.simd_size_and_type(fx.tcx); | 
 |         let lane_layout = fx.layout_of(lane_ty); | 
 |         match self.0 { | 
 |             CValueInner::ByVal(_) | CValueInner::ByValPair(_, _) => unreachable!(), | 
 |             CValueInner::ByRef(ptr, None) => { | 
 |                 let lane_idx = clif_intcast(fx, lane_idx, fx.pointer_type, false); | 
 |                 let field_offset = fx.bcx.ins().imul_imm(lane_idx, lane_layout.size.bytes() as i64); | 
 |                 let field_ptr = ptr.offset_value(fx, field_offset); | 
 |                 CValue::by_ref(field_ptr, lane_layout) | 
 |             } | 
 |             CValueInner::ByRef(_, Some(_)) => unreachable!(), | 
 |         } | 
 |     } | 
 |  | 
 |     /// If `ty` is signed, `const_val` must already be sign extended. | 
 |     pub(crate) fn const_val( | 
 |         fx: &mut FunctionCx<'_, '_, 'tcx>, | 
 |         layout: TyAndLayout<'tcx>, | 
 |         const_val: ty::ScalarInt, | 
 |     ) -> CValue<'tcx> { | 
 |         assert_eq!(const_val.size(), layout.size, "{:#?}: {:?}", const_val, layout); | 
 |         use cranelift_codegen::ir::immediates::{Ieee16, Ieee32, Ieee64, Ieee128}; | 
 |  | 
 |         let clif_ty = fx.clif_type(layout.ty).unwrap(); | 
 |  | 
 |         let val = match layout.ty.kind() { | 
 |             ty::Uint(UintTy::U128) | ty::Int(IntTy::I128) => { | 
 |                 let const_val = const_val.to_bits(layout.size); | 
 |                 let lsb = fx.bcx.ins().iconst(types::I64, const_val as u64 as i64); | 
 |                 let msb = fx.bcx.ins().iconst(types::I64, (const_val >> 64) as u64 as i64); | 
 |                 fx.bcx.ins().iconcat(lsb, msb) | 
 |             } | 
 |             ty::Bool | 
 |             | ty::Char | 
 |             | ty::Uint(_) | 
 |             | ty::Int(_) | 
 |             | ty::Ref(..) | 
 |             | ty::RawPtr(..) | 
 |             | ty::FnPtr(..) => { | 
 |                 let raw_val = const_val.size().truncate(const_val.to_bits(layout.size)); | 
 |                 fx.bcx.ins().iconst(clif_ty, raw_val as i64) | 
 |             } | 
 |             ty::Float(FloatTy::F16) => { | 
 |                 fx.bcx.ins().f16const(Ieee16::with_bits(u16::try_from(const_val).unwrap())) | 
 |             } | 
 |             ty::Float(FloatTy::F32) => { | 
 |                 fx.bcx.ins().f32const(Ieee32::with_bits(u32::try_from(const_val).unwrap())) | 
 |             } | 
 |             ty::Float(FloatTy::F64) => { | 
 |                 fx.bcx.ins().f64const(Ieee64::with_bits(u64::try_from(const_val).unwrap())) | 
 |             } | 
 |             ty::Float(FloatTy::F128) => { | 
 |                 let value = fx | 
 |                     .bcx | 
 |                     .func | 
 |                     .dfg | 
 |                     .constants | 
 |                     .insert(Ieee128::with_bits(u128::try_from(const_val).unwrap()).into()); | 
 |                 fx.bcx.ins().f128const(value) | 
 |             } | 
 |             _ => panic!( | 
 |                 "CValue::const_val for non bool/char/float/integer/pointer type {:?} is not allowed", | 
 |                 layout.ty | 
 |             ), | 
 |         }; | 
 |  | 
 |         CValue::by_val(val, layout) | 
 |     } | 
 |  | 
 |     pub(crate) fn cast_pointer_to(self, layout: TyAndLayout<'tcx>) -> Self { | 
 |         assert!(matches!(self.layout().ty.kind(), ty::Ref(..) | ty::RawPtr(..) | ty::FnPtr(..))); | 
 |         assert!(matches!(layout.ty.kind(), ty::Ref(..) | ty::RawPtr(..) | ty::FnPtr(..))); | 
 |         assert_eq!(self.layout().backend_repr, layout.backend_repr); | 
 |         CValue(self.0, layout) | 
 |     } | 
 | } | 
 |  | 
 | /// A place where you can write a value to or read a value from | 
 | #[derive(Debug, Copy, Clone)] | 
 | pub(crate) struct CPlace<'tcx> { | 
 |     inner: CPlaceInner, | 
 |     layout: TyAndLayout<'tcx>, | 
 | } | 
 |  | 
 | #[derive(Debug, Copy, Clone)] | 
 | enum CPlaceInner { | 
 |     Var(Local, Variable), | 
 |     VarPair(Local, Variable, Variable), | 
 |     Addr(Pointer, Option<Value>), | 
 | } | 
 |  | 
 | impl<'tcx> CPlace<'tcx> { | 
 |     pub(crate) fn layout(&self) -> TyAndLayout<'tcx> { | 
 |         self.layout | 
 |     } | 
 |  | 
 |     pub(crate) fn new_stack_slot( | 
 |         fx: &mut FunctionCx<'_, '_, 'tcx>, | 
 |         layout: TyAndLayout<'tcx>, | 
 |     ) -> CPlace<'tcx> { | 
 |         assert!(layout.is_sized()); | 
 |         if layout.size.bytes() == 0 { | 
 |             return CPlace { | 
 |                 inner: CPlaceInner::Addr(Pointer::dangling(layout.align.abi), None), | 
 |                 layout, | 
 |             }; | 
 |         } | 
 |  | 
 |         if layout.size.bytes() >= u64::from(u32::MAX - 16) { | 
 |             fx.tcx | 
 |                 .dcx() | 
 |                 .fatal(format!("values of type {} are too big to store on the stack", layout.ty)); | 
 |         } | 
 |  | 
 |         let stack_slot = fx.create_stack_slot( | 
 |             u32::try_from(layout.size.bytes()).unwrap(), | 
 |             u32::try_from(layout.align.abi.bytes()).unwrap(), | 
 |         ); | 
 |         CPlace { inner: CPlaceInner::Addr(stack_slot, None), layout } | 
 |     } | 
 |  | 
 |     pub(crate) fn new_var( | 
 |         fx: &mut FunctionCx<'_, '_, 'tcx>, | 
 |         local: Local, | 
 |         layout: TyAndLayout<'tcx>, | 
 |     ) -> CPlace<'tcx> { | 
 |         let var = Variable::from_u32(fx.next_ssa_var); | 
 |         fx.next_ssa_var += 1; | 
 |         fx.bcx.declare_var(var, fx.clif_type(layout.ty).unwrap()); | 
 |         CPlace { inner: CPlaceInner::Var(local, var), layout } | 
 |     } | 
 |  | 
 |     pub(crate) fn new_var_pair( | 
 |         fx: &mut FunctionCx<'_, '_, 'tcx>, | 
 |         local: Local, | 
 |         layout: TyAndLayout<'tcx>, | 
 |     ) -> CPlace<'tcx> { | 
 |         let var1 = Variable::from_u32(fx.next_ssa_var); | 
 |         fx.next_ssa_var += 1; | 
 |         let var2 = Variable::from_u32(fx.next_ssa_var); | 
 |         fx.next_ssa_var += 1; | 
 |  | 
 |         let (ty1, ty2) = fx.clif_pair_type(layout.ty).unwrap(); | 
 |         fx.bcx.declare_var(var1, ty1); | 
 |         fx.bcx.declare_var(var2, ty2); | 
 |         CPlace { inner: CPlaceInner::VarPair(local, var1, var2), layout } | 
 |     } | 
 |  | 
 |     pub(crate) fn for_ptr(ptr: Pointer, layout: TyAndLayout<'tcx>) -> CPlace<'tcx> { | 
 |         CPlace { inner: CPlaceInner::Addr(ptr, None), layout } | 
 |     } | 
 |  | 
 |     pub(crate) fn for_ptr_with_extra( | 
 |         ptr: Pointer, | 
 |         extra: Value, | 
 |         layout: TyAndLayout<'tcx>, | 
 |     ) -> CPlace<'tcx> { | 
 |         CPlace { inner: CPlaceInner::Addr(ptr, Some(extra)), layout } | 
 |     } | 
 |  | 
 |     pub(crate) fn to_cvalue(self, fx: &mut FunctionCx<'_, '_, 'tcx>) -> CValue<'tcx> { | 
 |         let layout = self.layout(); | 
 |         match self.inner { | 
 |             CPlaceInner::Var(_local, var) => { | 
 |                 let val = fx.bcx.use_var(var); | 
 |                 //fx.bcx.set_val_label(val, cranelift_codegen::ir::ValueLabel::new(var.index())); | 
 |                 CValue::by_val(val, layout) | 
 |             } | 
 |             CPlaceInner::VarPair(_local, var1, var2) => { | 
 |                 let val1 = fx.bcx.use_var(var1); | 
 |                 //fx.bcx.set_val_label(val1, cranelift_codegen::ir::ValueLabel::new(var1.index())); | 
 |                 let val2 = fx.bcx.use_var(var2); | 
 |                 //fx.bcx.set_val_label(val2, cranelift_codegen::ir::ValueLabel::new(var2.index())); | 
 |                 CValue::by_val_pair(val1, val2, layout) | 
 |             } | 
 |             CPlaceInner::Addr(ptr, extra) => { | 
 |                 if let Some(extra) = extra { | 
 |                     CValue::by_ref_unsized(ptr, extra, layout) | 
 |                 } else { | 
 |                     CValue::by_ref(ptr, layout) | 
 |                 } | 
 |             } | 
 |         } | 
 |     } | 
 |  | 
 |     pub(crate) fn debug_comment(self) -> (&'static str, String) { | 
 |         match self.inner { | 
 |             CPlaceInner::Var(_local, var) => ("ssa", format!("var={}", var.index())), | 
 |             CPlaceInner::VarPair(_local, var1, var2) => { | 
 |                 ("ssa", format!("var=({}, {})", var1.index(), var2.index())) | 
 |             } | 
 |             CPlaceInner::Addr(ptr, meta) => { | 
 |                 let meta = | 
 |                     if let Some(meta) = meta { format!(",meta={}", meta) } else { String::new() }; | 
 |                 match ptr.debug_base_and_offset() { | 
 |                     (crate::pointer::PointerBase::Addr(addr), offset) => { | 
 |                         ("reuse", format!("storage={}{}{}", addr, offset, meta)) | 
 |                     } | 
 |                     (crate::pointer::PointerBase::Stack(stack_slot), offset) => { | 
 |                         ("stack", format!("storage={}{}{}", stack_slot, offset, meta)) | 
 |                     } | 
 |                     (crate::pointer::PointerBase::Dangling(align), offset) => { | 
 |                         ("zst", format!("align={},offset={}", align.bytes(), offset)) | 
 |                     } | 
 |                 } | 
 |             } | 
 |         } | 
 |     } | 
 |  | 
 |     #[track_caller] | 
 |     pub(crate) fn to_ptr(self) -> Pointer { | 
 |         match self.inner { | 
 |             CPlaceInner::Addr(ptr, None) => ptr, | 
 |             CPlaceInner::Addr(_, Some(_)) => bug!("Expected sized cplace, found {:?}", self), | 
 |             CPlaceInner::Var(_, _) | CPlaceInner::VarPair(_, _, _) => { | 
 |                 bug!("Expected CPlace::Addr, found {:?}", self) | 
 |             } | 
 |         } | 
 |     } | 
 |  | 
 |     #[track_caller] | 
 |     pub(crate) fn to_ptr_unsized(self) -> (Pointer, Value) { | 
 |         match self.inner { | 
 |             CPlaceInner::Addr(ptr, Some(extra)) => (ptr, extra), | 
 |             CPlaceInner::Addr(_, None) | CPlaceInner::Var(_, _) | CPlaceInner::VarPair(_, _, _) => { | 
 |                 bug!("Expected unsized cplace, found {:?}", self) | 
 |             } | 
 |         } | 
 |     } | 
 |  | 
 |     pub(crate) fn try_to_ptr(self) -> Option<Pointer> { | 
 |         match self.inner { | 
 |             CPlaceInner::Var(_, _) | CPlaceInner::VarPair(_, _, _) => None, | 
 |             CPlaceInner::Addr(ptr, None) => Some(ptr), | 
 |             CPlaceInner::Addr(_, Some(_)) => bug!("Expected sized cplace, found {:?}", self), | 
 |         } | 
 |     } | 
 |  | 
 |     pub(crate) fn write_cvalue(self, fx: &mut FunctionCx<'_, '_, 'tcx>, from: CValue<'tcx>) { | 
 |         assert_assignable(fx, from.layout().ty, self.layout().ty, 16); | 
 |  | 
 |         self.write_cvalue_maybe_transmute(fx, from, "write_cvalue"); | 
 |     } | 
 |  | 
 |     pub(crate) fn write_cvalue_transmute( | 
 |         self, | 
 |         fx: &mut FunctionCx<'_, '_, 'tcx>, | 
 |         from: CValue<'tcx>, | 
 |     ) { | 
 |         self.write_cvalue_maybe_transmute(fx, from, "write_cvalue_transmute"); | 
 |     } | 
 |  | 
 |     fn write_cvalue_maybe_transmute( | 
 |         self, | 
 |         fx: &mut FunctionCx<'_, '_, 'tcx>, | 
 |         from: CValue<'tcx>, | 
 |         method: &'static str, | 
 |     ) { | 
 |         fn transmute_scalar<'tcx>( | 
 |             fx: &mut FunctionCx<'_, '_, 'tcx>, | 
 |             var: Variable, | 
 |             data: Value, | 
 |             dst_ty: Type, | 
 |         ) { | 
 |             let src_ty = fx.bcx.func.dfg.value_type(data); | 
 |             assert_eq!( | 
 |                 src_ty.bytes(), | 
 |                 dst_ty.bytes(), | 
 |                 "write_cvalue_transmute: {:?} -> {:?}", | 
 |                 src_ty, | 
 |                 dst_ty, | 
 |             ); | 
 |             let data = if src_ty == dst_ty { data } else { codegen_bitcast(fx, dst_ty, data) }; | 
 |             //fx.bcx.set_val_label(data, cranelift_codegen::ir::ValueLabel::new(var.index())); | 
 |             fx.bcx.def_var(var, data); | 
 |         } | 
 |  | 
 |         assert_eq!(self.layout().size, from.layout().size); | 
 |  | 
 |         if fx.clif_comments.enabled() { | 
 |             let inst = fx.bcx.func.layout.last_inst(fx.bcx.current_block().unwrap()).unwrap(); | 
 |             fx.add_post_comment( | 
 |                 inst, | 
 |                 format!( | 
 |                     "{}: {:?}: {:?} <- {:?}: {:?}", | 
 |                     method, | 
 |                     self.inner, | 
 |                     self.layout().ty, | 
 |                     from.0, | 
 |                     from.layout().ty | 
 |                 ), | 
 |             ); | 
 |         } | 
 |  | 
 |         let dst_layout = self.layout(); | 
 |         match self.inner { | 
 |             CPlaceInner::Var(_local, var) => { | 
 |                 let data = match from.1.backend_repr { | 
 |                     BackendRepr::Scalar(_) => CValue(from.0, dst_layout).load_scalar(fx), | 
 |                     _ => { | 
 |                         let (ptr, meta) = from.force_stack(fx); | 
 |                         assert!(meta.is_none()); | 
 |                         CValue(CValueInner::ByRef(ptr, None), dst_layout).load_scalar(fx) | 
 |                     } | 
 |                 }; | 
 |                 let dst_ty = fx.clif_type(self.layout().ty).unwrap(); | 
 |                 transmute_scalar(fx, var, data, dst_ty); | 
 |             } | 
 |             CPlaceInner::VarPair(_local, var1, var2) => { | 
 |                 let (data1, data2) = match from.1.backend_repr { | 
 |                     BackendRepr::ScalarPair(_, _) => { | 
 |                         CValue(from.0, dst_layout).load_scalar_pair(fx) | 
 |                     } | 
 |                     _ => { | 
 |                         let (ptr, meta) = from.force_stack(fx); | 
 |                         assert!(meta.is_none()); | 
 |                         CValue(CValueInner::ByRef(ptr, None), dst_layout).load_scalar_pair(fx) | 
 |                     } | 
 |                 }; | 
 |                 let (dst_ty1, dst_ty2) = fx.clif_pair_type(self.layout().ty).unwrap(); | 
 |                 transmute_scalar(fx, var1, data1, dst_ty1); | 
 |                 transmute_scalar(fx, var2, data2, dst_ty2); | 
 |             } | 
 |             CPlaceInner::Addr(_, Some(_)) => bug!("Can't write value to unsized place {:?}", self), | 
 |             CPlaceInner::Addr(to_ptr, None) => { | 
 |                 if dst_layout.size == Size::ZERO { | 
 |                     return; | 
 |                 } | 
 |  | 
 |                 let mut flags = MemFlags::new(); | 
 |                 flags.set_notrap(); | 
 |  | 
 |                 match from.0 { | 
 |                     CValueInner::ByVal(val) => { | 
 |                         to_ptr.store(fx, val, flags); | 
 |                     } | 
 |                     CValueInner::ByValPair(val1, val2) => match from.layout().backend_repr { | 
 |                         BackendRepr::ScalarPair(a_scalar, b_scalar) => { | 
 |                             let b_offset = | 
 |                                 scalar_pair_calculate_b_offset(fx.tcx, a_scalar, b_scalar); | 
 |                             to_ptr.store(fx, val1, flags); | 
 |                             to_ptr.offset(fx, b_offset).store(fx, val2, flags); | 
 |                         } | 
 |                         _ => { | 
 |                             bug!( | 
 |                                 "Non ScalarPair repr {:?} for ByValPair CValue", | 
 |                                 dst_layout.backend_repr | 
 |                             ) | 
 |                         } | 
 |                     }, | 
 |                     CValueInner::ByRef(from_ptr, None) => { | 
 |                         match from.layout().backend_repr { | 
 |                             BackendRepr::Scalar(_) => { | 
 |                                 let val = from.load_scalar(fx); | 
 |                                 to_ptr.store(fx, val, flags); | 
 |                                 return; | 
 |                             } | 
 |                             BackendRepr::ScalarPair(a_scalar, b_scalar) => { | 
 |                                 let b_offset = | 
 |                                     scalar_pair_calculate_b_offset(fx.tcx, a_scalar, b_scalar); | 
 |                                 let (val1, val2) = from.load_scalar_pair(fx); | 
 |                                 to_ptr.store(fx, val1, flags); | 
 |                                 to_ptr.offset(fx, b_offset).store(fx, val2, flags); | 
 |                                 return; | 
 |                             } | 
 |                             _ => {} | 
 |                         } | 
 |  | 
 |                         let from_addr = from_ptr.get_addr(fx); | 
 |                         let to_addr = to_ptr.get_addr(fx); | 
 |                         let src_layout = from.1; | 
 |                         let size = dst_layout.size.bytes(); | 
 |                         // `emit_small_memory_copy` uses `u8` for alignments, just use the maximum | 
 |                         // alignment that fits in a `u8` if the actual alignment is larger. | 
 |                         let src_align = src_layout.align.abi.bytes().try_into().unwrap_or(128); | 
 |                         let dst_align = dst_layout.align.abi.bytes().try_into().unwrap_or(128); | 
 |                         fx.bcx.emit_small_memory_copy( | 
 |                             fx.target_config, | 
 |                             to_addr, | 
 |                             from_addr, | 
 |                             size, | 
 |                             dst_align, | 
 |                             src_align, | 
 |                             true, | 
 |                             flags, | 
 |                         ); | 
 |                     } | 
 |                     CValueInner::ByRef(_, Some(_)) => todo!(), | 
 |                 } | 
 |             } | 
 |         } | 
 |     } | 
 |  | 
 |     /// Used for `ProjectionElem::Subtype`, `ty` has to be monomorphized before | 
 |     /// passed on. | 
 |     pub(crate) fn place_transmute_type( | 
 |         self, | 
 |         fx: &mut FunctionCx<'_, '_, 'tcx>, | 
 |         ty: Ty<'tcx>, | 
 |     ) -> CPlace<'tcx> { | 
 |         CPlace { inner: self.inner, layout: fx.layout_of(ty) } | 
 |     } | 
 |  | 
 |     pub(crate) fn place_field( | 
 |         self, | 
 |         fx: &mut FunctionCx<'_, '_, 'tcx>, | 
 |         field: FieldIdx, | 
 |     ) -> CPlace<'tcx> { | 
 |         let layout = self.layout(); | 
 |  | 
 |         match self.inner { | 
 |             CPlaceInner::VarPair(local, var1, var2) => { | 
 |                 let layout = layout.field(&*fx, field.index()); | 
 |  | 
 |                 match field.as_u32() { | 
 |                     0 => return CPlace { inner: CPlaceInner::Var(local, var1), layout }, | 
 |                     1 => return CPlace { inner: CPlaceInner::Var(local, var2), layout }, | 
 |                     _ => unreachable!("field should be 0 or 1"), | 
 |                 } | 
 |             } | 
 |             _ => {} | 
 |         } | 
 |  | 
 |         let (base, extra) = match self.inner { | 
 |             CPlaceInner::Addr(ptr, extra) => (ptr, extra), | 
 |             CPlaceInner::Var(_, _) | CPlaceInner::VarPair(_, _, _) => { | 
 |                 bug!("Expected CPlace::Addr, found {:?}", self) | 
 |             } | 
 |         }; | 
 |  | 
 |         let (field_ptr, field_layout) = codegen_field(fx, base, extra, layout, field); | 
 |         if fx.tcx.type_has_metadata(field_layout.ty, ty::TypingEnv::fully_monomorphized()) { | 
 |             CPlace::for_ptr_with_extra(field_ptr, extra.unwrap(), field_layout) | 
 |         } else { | 
 |             CPlace::for_ptr(field_ptr, field_layout) | 
 |         } | 
 |     } | 
 |  | 
 |     /// Like [`CPlace::place_field`] except handling ADTs containing a single array field in a way | 
 |     /// such that you can access individual lanes. | 
 |     pub(crate) fn place_lane( | 
 |         self, | 
 |         fx: &mut FunctionCx<'_, '_, 'tcx>, | 
 |         lane_idx: u64, | 
 |     ) -> CPlace<'tcx> { | 
 |         let layout = self.layout(); | 
 |         assert!(layout.ty.is_simd()); | 
 |         let (lane_count, lane_ty) = layout.ty.simd_size_and_type(fx.tcx); | 
 |         let lane_layout = fx.layout_of(lane_ty); | 
 |         assert!(lane_idx < lane_count); | 
 |  | 
 |         match self.inner { | 
 |             CPlaceInner::Var(_, _) => unreachable!(), | 
 |             CPlaceInner::VarPair(_, _, _) => unreachable!(), | 
 |             CPlaceInner::Addr(ptr, None) => { | 
 |                 let field_offset = lane_layout.size * lane_idx; | 
 |                 let field_ptr = ptr.offset_i64(fx, i64::try_from(field_offset.bytes()).unwrap()); | 
 |                 CPlace::for_ptr(field_ptr, lane_layout) | 
 |             } | 
 |             CPlaceInner::Addr(_, Some(_)) => unreachable!(), | 
 |         } | 
 |     } | 
 |  | 
 |     /// Like [`CPlace::place_field`] except using the passed type as lane type instead of the one | 
 |     /// specified by the vector type. | 
 |     pub(crate) fn place_typed_lane( | 
 |         self, | 
 |         fx: &mut FunctionCx<'_, '_, 'tcx>, | 
 |         lane_ty: Ty<'tcx>, | 
 |         lane_idx: u64, | 
 |     ) -> CPlace<'tcx> { | 
 |         let layout = self.layout(); | 
 |         assert!(layout.ty.is_simd()); | 
 |         let (orig_lane_count, orig_lane_ty) = layout.ty.simd_size_and_type(fx.tcx); | 
 |         let lane_layout = fx.layout_of(lane_ty); | 
 |         assert!( | 
 |             (lane_idx + 1) * lane_layout.size <= orig_lane_count * fx.layout_of(orig_lane_ty).size | 
 |         ); | 
 |  | 
 |         match self.inner { | 
 |             CPlaceInner::Var(_, _) => unreachable!(), | 
 |             CPlaceInner::VarPair(_, _, _) => unreachable!(), | 
 |             CPlaceInner::Addr(ptr, None) => { | 
 |                 let field_offset = lane_layout.size * lane_idx; | 
 |                 let field_ptr = ptr.offset_i64(fx, i64::try_from(field_offset.bytes()).unwrap()); | 
 |                 CPlace::for_ptr(field_ptr, lane_layout) | 
 |             } | 
 |             CPlaceInner::Addr(_, Some(_)) => unreachable!(), | 
 |         } | 
 |     } | 
 |  | 
 |     /// Write a value to an individual lane in a SIMD vector. | 
 |     pub(crate) fn write_lane_dyn( | 
 |         self, | 
 |         fx: &mut FunctionCx<'_, '_, 'tcx>, | 
 |         lane_idx: Value, | 
 |         value: CValue<'tcx>, | 
 |     ) { | 
 |         let layout = self.layout(); | 
 |         assert!(layout.ty.is_simd()); | 
 |         let (_lane_count, lane_ty) = layout.ty.simd_size_and_type(fx.tcx); | 
 |         let lane_layout = fx.layout_of(lane_ty); | 
 |         assert_eq!(lane_layout, value.layout()); | 
 |  | 
 |         match self.inner { | 
 |             CPlaceInner::Var(_, _) => unreachable!(), | 
 |             CPlaceInner::VarPair(_, _, _) => unreachable!(), | 
 |             CPlaceInner::Addr(ptr, None) => { | 
 |                 let lane_idx = clif_intcast(fx, lane_idx, fx.pointer_type, false); | 
 |                 let field_offset = fx | 
 |                     .bcx | 
 |                     .ins() | 
 |                     .imul_imm(lane_idx, i64::try_from(lane_layout.size.bytes()).unwrap()); | 
 |                 let field_ptr = ptr.offset_value(fx, field_offset); | 
 |                 CPlace::for_ptr(field_ptr, lane_layout).write_cvalue(fx, value); | 
 |             } | 
 |             CPlaceInner::Addr(_, Some(_)) => unreachable!(), | 
 |         } | 
 |     } | 
 |  | 
 |     pub(crate) fn place_index( | 
 |         self, | 
 |         fx: &mut FunctionCx<'_, '_, 'tcx>, | 
 |         index: Value, | 
 |     ) -> CPlace<'tcx> { | 
 |         let (elem_layout, ptr) = match self.layout().ty.kind() { | 
 |             ty::Array(elem_ty, _) => { | 
 |                 let elem_layout = fx.layout_of(*elem_ty); | 
 |                 match self.inner { | 
 |                     CPlaceInner::Addr(addr, None) => (elem_layout, addr), | 
 |                     CPlaceInner::Var(_, _) | 
 |                     | CPlaceInner::Addr(_, Some(_)) | 
 |                     | CPlaceInner::VarPair(_, _, _) => bug!("Can't index into {self:?}"), | 
 |                 } | 
 |             } | 
 |             ty::Slice(elem_ty) => (fx.layout_of(*elem_ty), self.to_ptr_unsized().0), | 
 |             _ => bug!("place_index({:?})", self.layout().ty), | 
 |         }; | 
 |  | 
 |         let offset = fx.bcx.ins().imul_imm(index, elem_layout.size.bytes() as i64); | 
 |  | 
 |         CPlace::for_ptr(ptr.offset_value(fx, offset), elem_layout) | 
 |     } | 
 |  | 
 |     pub(crate) fn place_deref(self, fx: &mut FunctionCx<'_, '_, 'tcx>) -> CPlace<'tcx> { | 
 |         let inner_layout = fx.layout_of(self.layout().ty.builtin_deref(true).unwrap()); | 
 |         if fx.tcx.type_has_metadata(inner_layout.ty, ty::TypingEnv::fully_monomorphized()) { | 
 |             let (addr, extra) = self.to_cvalue(fx).load_scalar_pair(fx); | 
 |             CPlace::for_ptr_with_extra(Pointer::new(addr), extra, inner_layout) | 
 |         } else { | 
 |             CPlace::for_ptr(Pointer::new(self.to_cvalue(fx).load_scalar(fx)), inner_layout) | 
 |         } | 
 |     } | 
 |  | 
 |     pub(crate) fn place_ref( | 
 |         self, | 
 |         fx: &mut FunctionCx<'_, '_, 'tcx>, | 
 |         layout: TyAndLayout<'tcx>, | 
 |     ) -> CValue<'tcx> { | 
 |         if fx.tcx.type_has_metadata(self.layout().ty, ty::TypingEnv::fully_monomorphized()) { | 
 |             let (ptr, extra) = self.to_ptr_unsized(); | 
 |             CValue::by_val_pair(ptr.get_addr(fx), extra, layout) | 
 |         } else { | 
 |             CValue::by_val(self.to_ptr().get_addr(fx), layout) | 
 |         } | 
 |     } | 
 |  | 
 |     pub(crate) fn downcast_variant( | 
 |         self, | 
 |         fx: &FunctionCx<'_, '_, 'tcx>, | 
 |         variant: VariantIdx, | 
 |     ) -> Self { | 
 |         assert!(self.layout().is_sized()); | 
 |         let layout = self.layout().for_variant(fx, variant); | 
 |         CPlace { inner: self.inner, layout } | 
 |     } | 
 | } | 
 |  | 
 | #[track_caller] | 
 | pub(crate) fn assert_assignable<'tcx>( | 
 |     fx: &FunctionCx<'_, '_, 'tcx>, | 
 |     from_ty: Ty<'tcx>, | 
 |     to_ty: Ty<'tcx>, | 
 |     limit: usize, | 
 | ) { | 
 |     if limit == 0 { | 
 |         // assert_assignable exists solely to catch bugs in cg_clif. it isn't necessary for | 
 |         // soundness. don't attempt to check deep types to avoid exponential behavior in certain | 
 |         // cases. | 
 |         return; | 
 |     } | 
 |     match (from_ty.kind(), to_ty.kind()) { | 
 |         (ty::Ref(_, a, _), ty::Ref(_, b, _)) | (ty::RawPtr(a, _), ty::RawPtr(b, _)) => { | 
 |             assert_assignable(fx, *a, *b, limit - 1); | 
 |         } | 
 |         (ty::Ref(_, a, _), ty::RawPtr(b, _)) | (ty::RawPtr(a, _), ty::Ref(_, b, _)) => { | 
 |             assert_assignable(fx, *a, *b, limit - 1); | 
 |         } | 
 |         (ty::FnPtr(..), ty::FnPtr(..)) => { | 
 |             let from_sig = fx | 
 |                 .tcx | 
 |                 .normalize_erasing_late_bound_regions(fx.typing_env(), from_ty.fn_sig(fx.tcx)); | 
 |             let FnSig { | 
 |                 inputs_and_output: types_from, | 
 |                 c_variadic: c_variadic_from, | 
 |                 safety: unsafety_from, | 
 |                 abi: abi_from, | 
 |             } = from_sig; | 
 |             let to_sig = | 
 |                 fx.tcx.normalize_erasing_late_bound_regions(fx.typing_env(), to_ty.fn_sig(fx.tcx)); | 
 |             let FnSig { | 
 |                 inputs_and_output: types_to, | 
 |                 c_variadic: c_variadic_to, | 
 |                 safety: unsafety_to, | 
 |                 abi: abi_to, | 
 |             } = to_sig; | 
 |             let mut types_from = types_from.iter(); | 
 |             let mut types_to = types_to.iter(); | 
 |             loop { | 
 |                 match (types_from.next(), types_to.next()) { | 
 |                     (Some(a), Some(b)) => assert_assignable(fx, a, b, limit - 1), | 
 |                     (None, None) => break, | 
 |                     (Some(_), None) | (None, Some(_)) => panic!("{:#?}/{:#?}", from_ty, to_ty), | 
 |                 } | 
 |             } | 
 |             assert_eq!( | 
 |                 c_variadic_from, c_variadic_to, | 
 |                 "Can't write fn ptr with incompatible sig {:?} to place with sig {:?}\n\n{:#?}", | 
 |                 from_sig, to_sig, fx, | 
 |             ); | 
 |             assert_eq!( | 
 |                 unsafety_from, unsafety_to, | 
 |                 "Can't write fn ptr with incompatible sig {:?} to place with sig {:?}\n\n{:#?}", | 
 |                 from_sig, to_sig, fx, | 
 |             ); | 
 |             assert_eq!( | 
 |                 abi_from, abi_to, | 
 |                 "Can't write fn ptr with incompatible sig {:?} to place with sig {:?}\n\n{:#?}", | 
 |                 from_sig, to_sig, fx, | 
 |             ); | 
 |             // fn(&T) -> for<'l> fn(&'l T) is allowed | 
 |         } | 
 |         (&ty::Dynamic(from_traits, _, _from_kind), &ty::Dynamic(to_traits, _, _to_kind)) => { | 
 |             // FIXME(dyn-star): Do the right thing with DynKinds | 
 |             for (from, to) in from_traits.iter().zip(to_traits) { | 
 |                 let from = fx.tcx.normalize_erasing_late_bound_regions(fx.typing_env(), from); | 
 |                 let to = fx.tcx.normalize_erasing_late_bound_regions(fx.typing_env(), to); | 
 |                 assert_eq!( | 
 |                     from, to, | 
 |                     "Can't write trait object of incompatible traits {:?} to place with traits {:?}\n\n{:#?}", | 
 |                     from_traits, to_traits, fx, | 
 |                 ); | 
 |             } | 
 |             // dyn for<'r> Trait<'r> -> dyn Trait<'_> is allowed | 
 |         } | 
 |         (&ty::Tuple(types_a), &ty::Tuple(types_b)) => { | 
 |             let mut types_a = types_a.iter(); | 
 |             let mut types_b = types_b.iter(); | 
 |             loop { | 
 |                 match (types_a.next(), types_b.next()) { | 
 |                     (Some(a), Some(b)) => assert_assignable(fx, a, b, limit - 1), | 
 |                     (None, None) => return, | 
 |                     (Some(_), None) | (None, Some(_)) => panic!("{:#?}/{:#?}", from_ty, to_ty), | 
 |                 } | 
 |             } | 
 |         } | 
 |         (&ty::Adt(adt_def_a, args_a), &ty::Adt(adt_def_b, args_b)) | 
 |             if adt_def_a.did() == adt_def_b.did() => | 
 |         { | 
 |             let mut types_a = args_a.types(); | 
 |             let mut types_b = args_b.types(); | 
 |             loop { | 
 |                 match (types_a.next(), types_b.next()) { | 
 |                     (Some(a), Some(b)) => assert_assignable(fx, a, b, limit - 1), | 
 |                     (None, None) => return, | 
 |                     (Some(_), None) | (None, Some(_)) => panic!("{:#?}/{:#?}", from_ty, to_ty), | 
 |                 } | 
 |             } | 
 |         } | 
 |         (ty::Array(a, _), ty::Array(b, _)) => assert_assignable(fx, *a, *b, limit - 1), | 
 |         (&ty::Closure(def_id_a, args_a), &ty::Closure(def_id_b, args_b)) | 
 |             if def_id_a == def_id_b => | 
 |         { | 
 |             let mut types_a = args_a.types(); | 
 |             let mut types_b = args_b.types(); | 
 |             loop { | 
 |                 match (types_a.next(), types_b.next()) { | 
 |                     (Some(a), Some(b)) => assert_assignable(fx, a, b, limit - 1), | 
 |                     (None, None) => return, | 
 |                     (Some(_), None) | (None, Some(_)) => panic!("{:#?}/{:#?}", from_ty, to_ty), | 
 |                 } | 
 |             } | 
 |         } | 
 |         (&ty::Coroutine(def_id_a, args_a), &ty::Coroutine(def_id_b, args_b)) | 
 |             if def_id_a == def_id_b => | 
 |         { | 
 |             let mut types_a = args_a.types(); | 
 |             let mut types_b = args_b.types(); | 
 |             loop { | 
 |                 match (types_a.next(), types_b.next()) { | 
 |                     (Some(a), Some(b)) => assert_assignable(fx, a, b, limit - 1), | 
 |                     (None, None) => return, | 
 |                     (Some(_), None) | (None, Some(_)) => panic!("{:#?}/{:#?}", from_ty, to_ty), | 
 |                 } | 
 |             } | 
 |         } | 
 |         (&ty::CoroutineWitness(def_id_a, args_a), &ty::CoroutineWitness(def_id_b, args_b)) | 
 |             if def_id_a == def_id_b => | 
 |         { | 
 |             let mut types_a = args_a.types(); | 
 |             let mut types_b = args_b.types(); | 
 |             loop { | 
 |                 match (types_a.next(), types_b.next()) { | 
 |                     (Some(a), Some(b)) => assert_assignable(fx, a, b, limit - 1), | 
 |                     (None, None) => return, | 
 |                     (Some(_), None) | (None, Some(_)) => panic!("{:#?}/{:#?}", from_ty, to_ty), | 
 |                 } | 
 |             } | 
 |         } | 
 |         _ => { | 
 |             assert_eq!( | 
 |                 from_ty, | 
 |                 to_ty, | 
 |                 "Can't write value with incompatible type {:?} to place with type {:?}\n\n{:#?}", | 
 |                 from_ty.kind(), | 
 |                 to_ty.kind(), | 
 |                 fx, | 
 |             ); | 
 |         } | 
 |     } | 
 | } |