1 //! Definition of [`CValue`] and [`CPlace`]
5 use cranelift_codegen::ir::immediates::Offset32;
7 fn codegen_field<'tcx>(
8 fx: &mut FunctionCx<'_, '_, 'tcx>,
11 layout: TyAndLayout<'tcx>,
13 ) -> (Pointer, TyAndLayout<'tcx>) {
14 let field_offset = layout.fields.offset(field.index());
15 let field_layout = layout.field(&*fx, field.index());
17 let simple = |fx: &mut FunctionCx<'_, '_, '_>| {
18 (base.offset_i64(fx, i64::try_from(field_offset.bytes()).unwrap()), field_layout)
21 if let Some(extra) = extra {
22 if !field_layout.is_unsized() {
25 match field_layout.ty.kind() {
26 ty::Slice(..) | ty::Str | ty::Foreign(..) => simple(fx),
27 ty::Adt(def, _) if def.repr.packed() => {
28 assert_eq!(layout.align.abi.bytes(), 1);
32 // We have to align the offset for DST's
33 let unaligned_offset = field_offset.bytes();
34 let (_, unsized_align) =
35 crate::unsize::size_and_align_of_dst(fx, field_layout, extra);
37 let one = fx.bcx.ins().iconst(pointer_ty(fx.tcx), 1);
38 let align_sub_1 = fx.bcx.ins().isub(unsized_align, one);
39 let and_lhs = fx.bcx.ins().iadd_imm(align_sub_1, unaligned_offset as i64);
40 let zero = fx.bcx.ins().iconst(pointer_ty(fx.tcx), 0);
41 let and_rhs = fx.bcx.ins().isub(zero, unsized_align);
42 let offset = fx.bcx.ins().band(and_lhs, and_rhs);
44 (base.offset_value(fx, offset), field_layout)
52 fn scalar_pair_calculate_b_offset(
57 let b_offset = a_scalar.value.size(&tcx).align_to(b_scalar.value.align(&tcx).abi);
58 Offset32::new(b_offset.bytes().try_into().unwrap())
62 #[derive(Debug, Copy, Clone)]
63 pub(crate) struct CValue<'tcx>(CValueInner, TyAndLayout<'tcx>);
65 #[derive(Debug, Copy, Clone)]
67 ByRef(Pointer, Option<Value>),
69 ByValPair(Value, Value),
72 impl<'tcx> CValue<'tcx> {
73 pub(crate) fn by_ref(ptr: Pointer, layout: TyAndLayout<'tcx>) -> CValue<'tcx> {
74 CValue(CValueInner::ByRef(ptr, None), layout)
77 pub(crate) fn by_ref_unsized(
80 layout: TyAndLayout<'tcx>,
82 CValue(CValueInner::ByRef(ptr, Some(meta)), layout)
85 pub(crate) fn by_val(value: Value, layout: TyAndLayout<'tcx>) -> CValue<'tcx> {
86 CValue(CValueInner::ByVal(value), layout)
89 pub(crate) fn by_val_pair(
92 layout: TyAndLayout<'tcx>,
94 CValue(CValueInner::ByValPair(value, extra), layout)
97 pub(crate) fn layout(&self) -> TyAndLayout<'tcx> {
102 pub(crate) fn force_stack(self, fx: &mut FunctionCx<'_, '_, 'tcx>) -> (Pointer, Option<Value>) {
105 CValueInner::ByRef(ptr, meta) => (ptr, meta),
106 CValueInner::ByVal(_) | CValueInner::ByValPair(_, _) => {
107 let cplace = CPlace::new_stack_slot(fx, layout);
108 cplace.write_cvalue(fx, self);
109 (cplace.to_ptr(), None)
114 pub(crate) fn try_to_ptr(self) -> Option<(Pointer, Option<Value>)> {
116 CValueInner::ByRef(ptr, meta) => Some((ptr, meta)),
117 CValueInner::ByVal(_) | CValueInner::ByValPair(_, _) => None,
121 /// Load a value with layout.abi of scalar
122 pub(crate) fn load_scalar(self, fx: &mut FunctionCx<'_, '_, 'tcx>) -> Value {
125 CValueInner::ByRef(ptr, None) => {
126 let clif_ty = match layout.abi {
127 Abi::Scalar(ref scalar) => scalar_to_clif_type(fx.tcx, scalar.clone()),
128 Abi::Vector { ref element, count } => {
129 scalar_to_clif_type(fx.tcx, element.clone())
130 .by(u16::try_from(count).unwrap())
133 _ => unreachable!("{:?}", layout.ty),
135 let mut flags = MemFlags::new();
137 ptr.load(fx, clif_ty, flags)
139 CValueInner::ByVal(value) => value,
140 CValueInner::ByRef(_, Some(_)) => bug!("load_scalar for unsized value not allowed"),
141 CValueInner::ByValPair(_, _) => bug!("Please use load_scalar_pair for ByValPair"),
145 /// Load a value pair with layout.abi of scalar pair
146 pub(crate) fn load_scalar_pair(self, fx: &mut FunctionCx<'_, '_, 'tcx>) -> (Value, Value) {
149 CValueInner::ByRef(ptr, None) => {
150 let (a_scalar, b_scalar) = match &layout.abi {
151 Abi::ScalarPair(a, b) => (a, b),
152 _ => unreachable!("load_scalar_pair({:?})", self),
154 let b_offset = scalar_pair_calculate_b_offset(fx.tcx, a_scalar, b_scalar);
155 let clif_ty1 = scalar_to_clif_type(fx.tcx, a_scalar.clone());
156 let clif_ty2 = scalar_to_clif_type(fx.tcx, b_scalar.clone());
157 let mut flags = MemFlags::new();
159 let val1 = ptr.load(fx, clif_ty1, flags);
160 let val2 = ptr.offset(fx, b_offset).load(fx, clif_ty2, flags);
163 CValueInner::ByRef(_, Some(_)) => {
164 bug!("load_scalar_pair for unsized value not allowed")
166 CValueInner::ByVal(_) => bug!("Please use load_scalar for ByVal"),
167 CValueInner::ByValPair(val1, val2) => (val1, val2),
171 pub(crate) fn value_field(
173 fx: &mut FunctionCx<'_, '_, 'tcx>,
178 CValueInner::ByVal(val) => match layout.abi {
179 Abi::Vector { element: _, count } => {
180 let count = u8::try_from(count).expect("SIMD type with more than 255 lanes???");
181 let field = u8::try_from(field.index()).unwrap();
182 assert!(field < count);
183 let lane = fx.bcx.ins().extractlane(val, field);
184 let field_layout = layout.field(&*fx, usize::from(field));
185 CValue::by_val(lane, field_layout)
187 _ => unreachable!("value_field for ByVal with abi {:?}", layout.abi),
189 CValueInner::ByValPair(val1, val2) => match layout.abi {
190 Abi::ScalarPair(_, _) => {
191 let val = match field.as_u32() {
194 _ => bug!("field should be 0 or 1"),
196 let field_layout = layout.field(&*fx, usize::from(field));
197 CValue::by_val(val, field_layout)
199 _ => unreachable!("value_field for ByValPair with abi {:?}", layout.abi),
201 CValueInner::ByRef(ptr, None) => {
202 let (field_ptr, field_layout) = codegen_field(fx, ptr, None, layout, field);
203 CValue::by_ref(field_ptr, field_layout)
205 CValueInner::ByRef(_, Some(_)) => todo!(),
209 /// Like [`CValue::value_field`] except handling ADTs containing a single array field in a way
210 /// such that you can access individual lanes.
211 pub(crate) fn value_lane(
213 fx: &mut FunctionCx<'_, '_, 'tcx>,
217 assert!(layout.ty.is_simd());
218 let (lane_count, lane_ty) = layout.ty.simd_size_and_type(fx.tcx);
219 let lane_layout = fx.layout_of(lane_ty);
220 assert!(lane_idx < lane_count);
222 CValueInner::ByVal(val) => match layout.abi {
223 Abi::Vector { element: _, count: _ } => {
224 assert!(lane_count <= u8::MAX.into(), "SIMD type with more than 255 lanes???");
225 let lane_idx = u8::try_from(lane_idx).unwrap();
226 let lane = fx.bcx.ins().extractlane(val, lane_idx);
227 CValue::by_val(lane, lane_layout)
229 _ => unreachable!("value_lane for ByVal with abi {:?}", layout.abi),
231 CValueInner::ByValPair(_, _) => unreachable!(),
232 CValueInner::ByRef(ptr, None) => {
233 let field_offset = lane_layout.size * lane_idx;
234 let field_ptr = ptr.offset_i64(fx, i64::try_from(field_offset.bytes()).unwrap());
235 CValue::by_ref(field_ptr, lane_layout)
237 CValueInner::ByRef(_, Some(_)) => unreachable!(),
241 pub(crate) fn unsize_value(self, fx: &mut FunctionCx<'_, '_, 'tcx>, dest: CPlace<'tcx>) {
242 crate::unsize::coerce_unsized_into(fx, self, dest);
245 /// If `ty` is signed, `const_val` must already be sign extended.
246 pub(crate) fn const_val(
247 fx: &mut FunctionCx<'_, '_, 'tcx>,
248 layout: TyAndLayout<'tcx>,
249 const_val: ty::ScalarInt,
251 assert_eq!(const_val.size(), layout.size, "{:#?}: {:?}", const_val, layout);
252 use cranelift_codegen::ir::immediates::{Ieee32, Ieee64};
254 let clif_ty = fx.clif_type(layout.ty).unwrap();
256 if let ty::Bool = layout.ty.kind() {
258 const_val == ty::ScalarInt::FALSE || const_val == ty::ScalarInt::TRUE,
259 "Invalid bool 0x{:032X}",
264 let val = match layout.ty.kind() {
265 ty::Uint(UintTy::U128) | ty::Int(IntTy::I128) => {
266 let const_val = const_val.to_bits(layout.size).unwrap();
267 let lsb = fx.bcx.ins().iconst(types::I64, const_val as u64 as i64);
268 let msb = fx.bcx.ins().iconst(types::I64, (const_val >> 64) as u64 as i64);
269 fx.bcx.ins().iconcat(lsb, msb)
271 ty::Bool | ty::Char | ty::Uint(_) | ty::Int(_) | ty::Ref(..) | ty::RawPtr(..) => {
272 fx.bcx.ins().iconst(clif_ty, const_val.to_bits(layout.size).unwrap() as i64)
274 ty::Float(FloatTy::F32) => {
275 fx.bcx.ins().f32const(Ieee32::with_bits(u32::try_from(const_val).unwrap()))
277 ty::Float(FloatTy::F64) => {
278 fx.bcx.ins().f64const(Ieee64::with_bits(u64::try_from(const_val).unwrap()))
281 "CValue::const_val for non bool/char/float/integer/pointer type {:?} is not allowed",
286 CValue::by_val(val, layout)
289 pub(crate) fn cast_pointer_to(self, layout: TyAndLayout<'tcx>) -> Self {
290 assert!(matches!(self.layout().ty.kind(), ty::Ref(..) | ty::RawPtr(..) | ty::FnPtr(..)));
291 assert!(matches!(layout.ty.kind(), ty::Ref(..) | ty::RawPtr(..) | ty::FnPtr(..)));
292 assert_eq!(self.layout().abi, layout.abi);
293 CValue(self.0, layout)
297 /// A place where you can write a value to or read a value from
298 #[derive(Debug, Copy, Clone)]
299 pub(crate) struct CPlace<'tcx> {
301 layout: TyAndLayout<'tcx>,
304 #[derive(Debug, Copy, Clone)]
305 pub(crate) enum CPlaceInner {
306 Var(Local, Variable),
307 VarPair(Local, Variable, Variable),
308 VarLane(Local, Variable, u8),
309 Addr(Pointer, Option<Value>),
312 impl<'tcx> CPlace<'tcx> {
313 pub(crate) fn layout(&self) -> TyAndLayout<'tcx> {
317 pub(crate) fn inner(&self) -> &CPlaceInner {
321 pub(crate) fn no_place(layout: TyAndLayout<'tcx>) -> CPlace<'tcx> {
322 CPlace { inner: CPlaceInner::Addr(Pointer::dangling(layout.align.pref), None), layout }
325 pub(crate) fn new_stack_slot(
326 fx: &mut FunctionCx<'_, '_, 'tcx>,
327 layout: TyAndLayout<'tcx>,
329 assert!(!layout.is_unsized());
330 if layout.size.bytes() == 0 {
331 return CPlace::no_place(layout);
334 let stack_slot = fx.bcx.create_stack_slot(StackSlotData {
335 kind: StackSlotKind::ExplicitSlot,
336 // FIXME Don't force the size to a multiple of 16 bytes once Cranelift gets a way to
337 // specify stack slot alignment.
338 size: (u32::try_from(layout.size.bytes()).unwrap() + 15) / 16 * 16,
341 CPlace { inner: CPlaceInner::Addr(Pointer::stack_slot(stack_slot), None), layout }
344 pub(crate) fn new_var(
345 fx: &mut FunctionCx<'_, '_, 'tcx>,
347 layout: TyAndLayout<'tcx>,
349 let var = Variable::with_u32(fx.next_ssa_var);
350 fx.next_ssa_var += 1;
351 fx.bcx.declare_var(var, fx.clif_type(layout.ty).unwrap());
352 CPlace { inner: CPlaceInner::Var(local, var), layout }
355 pub(crate) fn new_var_pair(
356 fx: &mut FunctionCx<'_, '_, 'tcx>,
358 layout: TyAndLayout<'tcx>,
360 let var1 = Variable::with_u32(fx.next_ssa_var);
361 fx.next_ssa_var += 1;
362 let var2 = Variable::with_u32(fx.next_ssa_var);
363 fx.next_ssa_var += 1;
365 let (ty1, ty2) = fx.clif_pair_type(layout.ty).unwrap();
366 fx.bcx.declare_var(var1, ty1);
367 fx.bcx.declare_var(var2, ty2);
368 CPlace { inner: CPlaceInner::VarPair(local, var1, var2), layout }
371 pub(crate) fn for_ptr(ptr: Pointer, layout: TyAndLayout<'tcx>) -> CPlace<'tcx> {
372 CPlace { inner: CPlaceInner::Addr(ptr, None), layout }
375 pub(crate) fn for_ptr_with_extra(
378 layout: TyAndLayout<'tcx>,
380 CPlace { inner: CPlaceInner::Addr(ptr, Some(extra)), layout }
383 pub(crate) fn to_cvalue(self, fx: &mut FunctionCx<'_, '_, 'tcx>) -> CValue<'tcx> {
384 let layout = self.layout();
386 CPlaceInner::Var(_local, var) => {
387 let val = fx.bcx.use_var(var);
388 //fx.bcx.set_val_label(val, cranelift_codegen::ir::ValueLabel::new(var.index()));
389 CValue::by_val(val, layout)
391 CPlaceInner::VarPair(_local, var1, var2) => {
392 let val1 = fx.bcx.use_var(var1);
393 //fx.bcx.set_val_label(val1, cranelift_codegen::ir::ValueLabel::new(var1.index()));
394 let val2 = fx.bcx.use_var(var2);
395 //fx.bcx.set_val_label(val2, cranelift_codegen::ir::ValueLabel::new(var2.index()));
396 CValue::by_val_pair(val1, val2, layout)
398 CPlaceInner::VarLane(_local, var, lane) => {
399 let val = fx.bcx.use_var(var);
400 //fx.bcx.set_val_label(val, cranelift_codegen::ir::ValueLabel::new(var.index()));
401 let val = fx.bcx.ins().extractlane(val, lane);
402 CValue::by_val(val, layout)
404 CPlaceInner::Addr(ptr, extra) => {
405 if let Some(extra) = extra {
406 CValue::by_ref_unsized(ptr, extra, layout)
408 CValue::by_ref(ptr, layout)
414 pub(crate) fn to_ptr(self) -> Pointer {
415 match self.to_ptr_maybe_unsized() {
417 (_, Some(_)) => bug!("Expected sized cplace, found {:?}", self),
421 pub(crate) fn to_ptr_maybe_unsized(self) -> (Pointer, Option<Value>) {
423 CPlaceInner::Addr(ptr, extra) => (ptr, extra),
424 CPlaceInner::Var(_, _)
425 | CPlaceInner::VarPair(_, _, _)
426 | CPlaceInner::VarLane(_, _, _) => bug!("Expected CPlace::Addr, found {:?}", self),
430 pub(crate) fn write_cvalue(self, fx: &mut FunctionCx<'_, '_, 'tcx>, from: CValue<'tcx>) {
431 assert_assignable(fx, from.layout().ty, self.layout().ty);
433 self.write_cvalue_maybe_transmute(fx, from, "write_cvalue");
436 pub(crate) fn write_cvalue_transmute(
438 fx: &mut FunctionCx<'_, '_, 'tcx>,
441 self.write_cvalue_maybe_transmute(fx, from, "write_cvalue_transmute");
444 fn write_cvalue_maybe_transmute(
446 fx: &mut FunctionCx<'_, '_, 'tcx>,
448 method: &'static str,
450 fn transmute_value<'tcx>(
451 fx: &mut FunctionCx<'_, '_, 'tcx>,
456 let src_ty = fx.bcx.func.dfg.value_type(data);
460 "write_cvalue_transmute: {:?} -> {:?}",
464 let data = match (src_ty, dst_ty) {
465 (_, _) if src_ty == dst_ty => data,
467 // This is a `write_cvalue_transmute`.
468 (types::I32, types::F32)
469 | (types::F32, types::I32)
470 | (types::I64, types::F64)
471 | (types::F64, types::I64) => fx.bcx.ins().bitcast(dst_ty, data),
472 _ if src_ty.is_vector() && dst_ty.is_vector() => {
473 fx.bcx.ins().raw_bitcast(dst_ty, data)
475 _ if src_ty.is_vector() || dst_ty.is_vector() => {
476 // FIXME do something more efficient for transmutes between vectors and integers.
477 let stack_slot = fx.bcx.create_stack_slot(StackSlotData {
478 kind: StackSlotKind::ExplicitSlot,
479 // FIXME Don't force the size to a multiple of 16 bytes once Cranelift gets a way to
480 // specify stack slot alignment.
481 size: (src_ty.bytes() + 15) / 16 * 16,
484 let ptr = Pointer::stack_slot(stack_slot);
485 ptr.store(fx, data, MemFlags::trusted());
486 ptr.load(fx, dst_ty, MemFlags::trusted())
489 // `CValue`s should never contain SSA-only types, so if you ended
490 // up here having seen an error like `B1 -> I8`, then before
491 // calling `write_cvalue` you need to add a `bint` instruction.
492 _ => unreachable!("write_cvalue_transmute: {:?} -> {:?}", src_ty, dst_ty),
494 //fx.bcx.set_val_label(data, cranelift_codegen::ir::ValueLabel::new(var.index()));
495 fx.bcx.def_var(var, data);
498 assert_eq!(self.layout().size, from.layout().size);
500 if fx.clif_comments.enabled() {
501 use cranelift_codegen::cursor::{Cursor, CursorPosition};
502 let cur_block = match fx.bcx.cursor().position() {
503 CursorPosition::After(block) => block,
507 fx.bcx.func.layout.last_inst(cur_block).unwrap(),
509 "{}: {:?}: {:?} <- {:?}: {:?}",
519 let dst_layout = self.layout();
520 let to_ptr = match self.inner {
521 CPlaceInner::Var(_local, var) => {
522 let data = CValue(from.0, dst_layout).load_scalar(fx);
523 let dst_ty = fx.clif_type(self.layout().ty).unwrap();
524 transmute_value(fx, var, data, dst_ty);
527 CPlaceInner::VarPair(_local, var1, var2) => {
528 let (data1, data2) = CValue(from.0, dst_layout).load_scalar_pair(fx);
529 let (dst_ty1, dst_ty2) = fx.clif_pair_type(self.layout().ty).unwrap();
530 transmute_value(fx, var1, data1, dst_ty1);
531 transmute_value(fx, var2, data2, dst_ty2);
534 CPlaceInner::VarLane(_local, var, lane) => {
535 let data = from.load_scalar(fx);
537 // First get the old vector
538 let vector = fx.bcx.use_var(var);
539 //fx.bcx.set_val_label(vector, cranelift_codegen::ir::ValueLabel::new(var.index()));
541 // Next insert the written lane into the vector
542 let vector = fx.bcx.ins().insertlane(vector, data, lane);
544 // Finally write the new vector
545 //fx.bcx.set_val_label(vector, cranelift_codegen::ir::ValueLabel::new(var.index()));
546 fx.bcx.def_var(var, vector);
550 CPlaceInner::Addr(ptr, None) => {
551 if dst_layout.size == Size::ZERO || dst_layout.abi == Abi::Uninhabited {
556 CPlaceInner::Addr(_, Some(_)) => bug!("Can't write value to unsized place {:?}", self),
559 let mut flags = MemFlags::new();
561 match from.layout().abi {
562 // FIXME make Abi::Vector work too
564 let val = from.load_scalar(fx);
565 to_ptr.store(fx, val, flags);
568 Abi::ScalarPair(ref a_scalar, ref b_scalar) => {
569 let (value, extra) = from.load_scalar_pair(fx);
570 let b_offset = scalar_pair_calculate_b_offset(fx.tcx, a_scalar, b_scalar);
571 to_ptr.store(fx, value, flags);
572 to_ptr.offset(fx, b_offset).store(fx, extra, flags);
579 CValueInner::ByVal(val) => {
580 to_ptr.store(fx, val, flags);
582 CValueInner::ByValPair(_, _) => {
583 bug!("Non ScalarPair abi {:?} for ByValPair CValue", dst_layout.abi);
585 CValueInner::ByRef(from_ptr, None) => {
586 let from_addr = from_ptr.get_addr(fx);
587 let to_addr = to_ptr.get_addr(fx);
588 let src_layout = from.1;
589 let size = dst_layout.size.bytes();
590 let src_align = src_layout.align.abi.bytes() as u8;
591 let dst_align = dst_layout.align.abi.bytes() as u8;
592 fx.bcx.emit_small_memory_copy(
593 fx.module.target_config(),
603 CValueInner::ByRef(_, Some(_)) => todo!(),
607 pub(crate) fn place_field(
609 fx: &mut FunctionCx<'_, '_, 'tcx>,
612 let layout = self.layout();
615 CPlaceInner::Var(local, var) => {
616 if let Abi::Vector { .. } = layout.abi {
618 inner: CPlaceInner::VarLane(local, var, field.as_u32().try_into().unwrap()),
619 layout: layout.field(fx, field.as_u32().try_into().unwrap()),
623 CPlaceInner::VarPair(local, var1, var2) => {
624 let layout = layout.field(&*fx, field.index());
626 match field.as_u32() {
627 0 => return CPlace { inner: CPlaceInner::Var(local, var1), layout },
628 1 => return CPlace { inner: CPlaceInner::Var(local, var2), layout },
629 _ => unreachable!("field should be 0 or 1"),
635 let (base, extra) = self.to_ptr_maybe_unsized();
637 let (field_ptr, field_layout) = codegen_field(fx, base, extra, layout, field);
638 if field_layout.is_unsized() {
639 CPlace::for_ptr_with_extra(field_ptr, extra.unwrap(), field_layout)
641 CPlace::for_ptr(field_ptr, field_layout)
645 /// Like [`CPlace::place_field`] except handling ADTs containing a single array field in a way
646 /// such that you can access individual lanes.
647 pub(crate) fn place_lane(
649 fx: &mut FunctionCx<'_, '_, 'tcx>,
652 let layout = self.layout();
653 assert!(layout.ty.is_simd());
654 let (lane_count, lane_ty) = layout.ty.simd_size_and_type(fx.tcx);
655 let lane_layout = fx.layout_of(lane_ty);
656 assert!(lane_idx < lane_count);
659 CPlaceInner::Var(local, var) => {
660 assert!(matches!(layout.abi, Abi::Vector { .. }));
662 inner: CPlaceInner::VarLane(local, var, lane_idx.try_into().unwrap()),
666 CPlaceInner::VarPair(_, _, _) => unreachable!(),
667 CPlaceInner::VarLane(_, _, _) => unreachable!(),
668 CPlaceInner::Addr(ptr, None) => {
669 let field_offset = lane_layout.size * lane_idx;
670 let field_ptr = ptr.offset_i64(fx, i64::try_from(field_offset.bytes()).unwrap());
671 CPlace::for_ptr(field_ptr, lane_layout)
673 CPlaceInner::Addr(_, Some(_)) => unreachable!(),
677 pub(crate) fn place_index(
679 fx: &mut FunctionCx<'_, '_, 'tcx>,
682 let (elem_layout, ptr) = match self.layout().ty.kind() {
683 ty::Array(elem_ty, _) => (fx.layout_of(elem_ty), self.to_ptr()),
684 ty::Slice(elem_ty) => (fx.layout_of(elem_ty), self.to_ptr_maybe_unsized().0),
685 _ => bug!("place_index({:?})", self.layout().ty),
688 let offset = fx.bcx.ins().imul_imm(index, elem_layout.size.bytes() as i64);
690 CPlace::for_ptr(ptr.offset_value(fx, offset), elem_layout)
693 pub(crate) fn place_deref(self, fx: &mut FunctionCx<'_, '_, 'tcx>) -> CPlace<'tcx> {
694 let inner_layout = fx.layout_of(self.layout().ty.builtin_deref(true).unwrap().ty);
695 if has_ptr_meta(fx.tcx, inner_layout.ty) {
696 let (addr, extra) = self.to_cvalue(fx).load_scalar_pair(fx);
697 CPlace::for_ptr_with_extra(Pointer::new(addr), extra, inner_layout)
699 CPlace::for_ptr(Pointer::new(self.to_cvalue(fx).load_scalar(fx)), inner_layout)
703 pub(crate) fn place_ref(
705 fx: &mut FunctionCx<'_, '_, 'tcx>,
706 layout: TyAndLayout<'tcx>,
708 if has_ptr_meta(fx.tcx, self.layout().ty) {
709 let (ptr, extra) = self.to_ptr_maybe_unsized();
712 extra.expect("unsized type without metadata"),
716 CValue::by_val(self.to_ptr().get_addr(fx), layout)
720 pub(crate) fn downcast_variant(
722 fx: &FunctionCx<'_, '_, 'tcx>,
725 assert!(!self.layout().is_unsized());
726 let layout = self.layout().for_variant(fx, variant);
727 CPlace { inner: self.inner, layout }
732 pub(crate) fn assert_assignable<'tcx>(
733 fx: &FunctionCx<'_, '_, 'tcx>,
737 match (from_ty.kind(), to_ty.kind()) {
738 (ty::Ref(_, a, _), ty::Ref(_, b, _))
740 ty::RawPtr(TypeAndMut { ty: a, mutbl: _ }),
741 ty::RawPtr(TypeAndMut { ty: b, mutbl: _ }),
743 assert_assignable(fx, a, b);
745 (ty::Ref(_, a, _), ty::RawPtr(TypeAndMut { ty: b, mutbl: _ }))
746 | (ty::RawPtr(TypeAndMut { ty: a, mutbl: _ }), ty::Ref(_, b, _)) => {
747 assert_assignable(fx, a, b);
749 (ty::FnPtr(_), ty::FnPtr(_)) => {
750 let from_sig = fx.tcx.normalize_erasing_late_bound_regions(
751 ParamEnv::reveal_all(),
752 from_ty.fn_sig(fx.tcx),
756 .normalize_erasing_late_bound_regions(ParamEnv::reveal_all(), to_ty.fn_sig(fx.tcx));
759 "Can't write fn ptr with incompatible sig {:?} to place with sig {:?}\n\n{:#?}",
760 from_sig, to_sig, fx,
762 // fn(&T) -> for<'l> fn(&'l T) is allowed
764 (&ty::Dynamic(from_traits, _), &ty::Dynamic(to_traits, _)) => {
765 for (from, to) in from_traits.iter().zip(to_traits) {
767 fx.tcx.normalize_erasing_late_bound_regions(ParamEnv::reveal_all(), from);
768 let to = fx.tcx.normalize_erasing_late_bound_regions(ParamEnv::reveal_all(), to);
771 "Can't write trait object of incompatible traits {:?} to place with traits {:?}\n\n{:#?}",
772 from_traits, to_traits, fx,
775 // dyn for<'r> Trait<'r> -> dyn Trait<'_> is allowed
777 (&ty::Adt(adt_def_a, substs_a), &ty::Adt(adt_def_b, substs_b))
778 if adt_def_a.did == adt_def_b.did =>
780 let mut types_a = substs_a.types();
781 let mut types_b = substs_b.types();
783 match (types_a.next(), types_b.next()) {
784 (Some(a), Some(b)) => assert_assignable(fx, a, b),
785 (None, None) => return,
786 (Some(_), None) | (None, Some(_)) => panic!("{:#?}/{:#?}", from_ty, to_ty),
793 "Can't write value with incompatible type {:?} to place with type {:?}\n\n{:#?}",