3 use cranelift_codegen::ir::immediates::Offset32;
5 fn codegen_field<'tcx>(
6 fx: &mut FunctionCx<'_, 'tcx, impl Backend>,
9 layout: TyAndLayout<'tcx>,
11 ) -> (Pointer, TyAndLayout<'tcx>) {
12 let field_offset = layout.fields.offset(field.index());
13 let field_layout = layout.field(&*fx, field.index());
15 let simple = |fx: &mut FunctionCx<_>| {
17 base.offset_i64(fx, i64::try_from(field_offset.bytes()).unwrap()),
22 if let Some(extra) = extra {
23 if !field_layout.is_unsized() {
26 match field_layout.ty.kind {
27 ty::Slice(..) | ty::Str | ty::Foreign(..) => return simple(fx),
28 ty::Adt(def, _) if def.repr.packed() => {
29 assert_eq!(layout.align.abi.bytes(), 1);
33 // We have to align the offset for DST's
34 let unaligned_offset = field_offset.bytes();
35 let (_, unsized_align) = 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);
45 base.offset_value(fx, offset),
55 fn scalar_pair_calculate_b_offset(tcx: TyCtxt<'_>, a_scalar: &Scalar, b_scalar: &Scalar) -> Offset32 {
56 let b_offset = a_scalar
59 .align_to(b_scalar.value.align(&tcx).abi);
60 Offset32::new(b_offset.bytes().try_into().unwrap())
64 #[derive(Debug, Copy, Clone)]
65 pub(crate) struct CValue<'tcx>(CValueInner, TyAndLayout<'tcx>);
67 #[derive(Debug, Copy, Clone)]
69 ByRef(Pointer, Option<Value>),
71 ByValPair(Value, Value),
74 impl<'tcx> CValue<'tcx> {
75 pub(crate) fn by_ref(ptr: Pointer, layout: TyAndLayout<'tcx>) -> CValue<'tcx> {
76 CValue(CValueInner::ByRef(ptr, None), layout)
79 pub(crate) fn by_ref_unsized(ptr: Pointer, meta: Value, layout: TyAndLayout<'tcx>) -> CValue<'tcx> {
80 CValue(CValueInner::ByRef(ptr, Some(meta)), layout)
83 pub(crate) fn by_val(value: Value, layout: TyAndLayout<'tcx>) -> CValue<'tcx> {
84 CValue(CValueInner::ByVal(value), layout)
87 pub(crate) fn by_val_pair(value: Value, extra: Value, layout: TyAndLayout<'tcx>) -> CValue<'tcx> {
88 CValue(CValueInner::ByValPair(value, extra), layout)
91 pub(crate) fn layout(&self) -> TyAndLayout<'tcx> {
96 pub(crate) fn force_stack<'a>(self, fx: &mut FunctionCx<'_, 'tcx, impl Backend>) -> (Pointer, Option<Value>) {
99 CValueInner::ByRef(ptr, meta) => (ptr, meta),
100 CValueInner::ByVal(_) | CValueInner::ByValPair(_, _) => {
101 let cplace = CPlace::new_stack_slot(fx, layout);
102 cplace.write_cvalue(fx, self);
103 (cplace.to_ptr(fx), None)
108 pub(crate) fn try_to_ptr(self) -> Option<(Pointer, Option<Value>)> {
110 CValueInner::ByRef(ptr, meta) => Some((ptr, meta)),
111 CValueInner::ByVal(_) | CValueInner::ByValPair(_, _) => None,
115 /// Load a value with layout.abi of scalar
116 pub(crate) fn load_scalar<'a>(self, fx: &mut FunctionCx<'_, 'tcx, impl Backend>) -> Value {
119 CValueInner::ByRef(ptr, None) => {
120 let clif_ty = match layout.abi {
121 layout::Abi::Scalar(ref scalar) => scalar_to_clif_type(fx.tcx, scalar.clone()),
122 layout::Abi::Vector { ref element, count } => {
123 scalar_to_clif_type(fx.tcx, element.clone())
124 .by(u16::try_from(count).unwrap()).unwrap()
128 ptr.load(fx, clif_ty, MemFlags::new())
130 CValueInner::ByVal(value) => value,
131 CValueInner::ByRef(_, Some(_)) => bug!("load_scalar for unsized value not allowed"),
132 CValueInner::ByValPair(_, _) => bug!("Please use load_scalar_pair for ByValPair"),
136 /// Load a value pair with layout.abi of scalar pair
137 pub(crate) fn load_scalar_pair<'a>(
139 fx: &mut FunctionCx<'_, 'tcx, impl Backend>,
140 ) -> (Value, Value) {
143 CValueInner::ByRef(ptr, None) => {
144 let (a_scalar, b_scalar) = match &layout.abi {
145 layout::Abi::ScalarPair(a, b) => (a, b),
146 _ => unreachable!("load_scalar_pair({:?})", self),
148 let b_offset = scalar_pair_calculate_b_offset(fx.tcx, a_scalar, b_scalar);
149 let clif_ty1 = scalar_to_clif_type(fx.tcx, a_scalar.clone());
150 let clif_ty2 = scalar_to_clif_type(fx.tcx, b_scalar.clone());
151 let val1 = ptr.load(fx, clif_ty1, MemFlags::new());
152 let val2 = ptr.offset(fx, b_offset).load(fx, clif_ty2, MemFlags::new());
155 CValueInner::ByRef(_, Some(_)) => bug!("load_scalar_pair for unsized value not allowed"),
156 CValueInner::ByVal(_) => bug!("Please use load_scalar for ByVal"),
157 CValueInner::ByValPair(val1, val2) => (val1, val2),
161 pub(crate) fn value_field<'a>(
163 fx: &mut FunctionCx<'_, 'tcx, impl Backend>,
168 CValueInner::ByVal(val) => {
170 layout::Abi::Vector { element: _, count } => {
171 let count = u8::try_from(count).expect("SIMD type with more than 255 lanes???");
172 let field = u8::try_from(field.index()).unwrap();
173 assert!(field < count);
174 let lane = fx.bcx.ins().extractlane(val, field);
175 let field_layout = layout.field(&*fx, usize::from(field));
176 CValue::by_val(lane, field_layout)
178 _ => unreachable!("value_field for ByVal with abi {:?}", layout.abi),
181 CValueInner::ByRef(ptr, None) => {
182 let (field_ptr, field_layout) = codegen_field(fx, ptr, None, layout, field);
183 CValue::by_ref(field_ptr, field_layout)
185 CValueInner::ByRef(_, Some(_)) => todo!(),
186 _ => bug!("place_field for {:?}", self),
190 pub(crate) fn unsize_value<'a>(self, fx: &mut FunctionCx<'_, 'tcx, impl Backend>, dest: CPlace<'tcx>) {
191 crate::unsize::coerce_unsized_into(fx, self, dest);
194 /// If `ty` is signed, `const_val` must already be sign extended.
195 pub(crate) fn const_val(
196 fx: &mut FunctionCx<'_, 'tcx, impl Backend>,
197 layout: TyAndLayout<'tcx>,
200 use cranelift_codegen::ir::immediates::{Ieee32, Ieee64};
202 let clif_ty = fx.clif_type(layout.ty).unwrap();
204 match layout.ty.kind {
205 ty::TyKind::Bool => {
206 assert!(const_val == 0 || const_val == 1, "Invalid bool 0x{:032X}", const_val);
211 let val = match layout.ty.kind {
212 ty::TyKind::Uint(UintTy::U128) | ty::TyKind::Int(IntTy::I128) => {
213 let lsb = fx.bcx.ins().iconst(types::I64, const_val as u64 as i64);
217 .iconst(types::I64, (const_val >> 64) as u64 as i64);
218 fx.bcx.ins().iconcat(lsb, msb)
220 ty::TyKind::Bool | ty::TyKind::Char | ty::TyKind::Uint(_) | ty::TyKind::Ref(..)
221 | ty::TyKind::RawPtr(..) => {
225 .iconst(clif_ty, u64::try_from(const_val).expect("uint") as i64)
227 ty::TyKind::Int(_) => {
228 let const_val = rustc::mir::interpret::sign_extend(const_val, layout.size);
229 fx.bcx.ins().iconst(clif_ty, i64::try_from(const_val as i128).unwrap())
231 ty::TyKind::Float(FloatTy::F32) => {
232 fx.bcx.ins().f32const(Ieee32::with_bits(u32::try_from(const_val).unwrap()))
234 ty::TyKind::Float(FloatTy::F64) => {
235 fx.bcx.ins().f64const(Ieee64::with_bits(u64::try_from(const_val).unwrap()))
238 "CValue::const_val for non bool/char/float/integer/pointer type {:?} is not allowed",
243 CValue::by_val(val, layout)
246 pub(crate) fn unchecked_cast_to(self, layout: TyAndLayout<'tcx>) -> Self {
247 CValue(self.0, layout)
251 /// A place where you can write a value to or read a value from
252 #[derive(Debug, Copy, Clone)]
253 pub(crate) struct CPlace<'tcx> {
255 layout: TyAndLayout<'tcx>,
258 #[derive(Debug, Copy, Clone)]
259 pub(crate) enum CPlaceInner {
261 Addr(Pointer, Option<Value>),
265 impl<'tcx> CPlace<'tcx> {
266 pub(crate) fn layout(&self) -> TyAndLayout<'tcx> {
270 pub(crate) fn inner(&self) -> &CPlaceInner {
274 pub(crate) fn no_place(layout: TyAndLayout<'tcx>) -> CPlace<'tcx> {
276 inner: CPlaceInner::NoPlace,
281 pub(crate) fn new_stack_slot(
282 fx: &mut FunctionCx<'_, 'tcx, impl Backend>,
283 layout: TyAndLayout<'tcx>,
285 assert!(!layout.is_unsized());
286 if layout.size.bytes() == 0 {
288 inner: CPlaceInner::NoPlace,
293 let stack_slot = fx.bcx.create_stack_slot(StackSlotData {
294 kind: StackSlotKind::ExplicitSlot,
295 size: layout.size.bytes() as u32,
299 inner: CPlaceInner::Addr(Pointer::stack_slot(stack_slot), None),
304 pub(crate) fn new_var(
305 fx: &mut FunctionCx<'_, 'tcx, impl Backend>,
307 layout: TyAndLayout<'tcx>,
310 .declare_var(mir_var(local), fx.clif_type(layout.ty).unwrap());
312 inner: CPlaceInner::Var(local),
317 pub(crate) fn for_ptr(ptr: Pointer, layout: TyAndLayout<'tcx>) -> CPlace<'tcx> {
319 inner: CPlaceInner::Addr(ptr, None),
324 pub(crate) fn for_ptr_with_extra(ptr: Pointer, extra: Value, layout: TyAndLayout<'tcx>) -> CPlace<'tcx> {
326 inner: CPlaceInner::Addr(ptr, Some(extra)),
331 pub(crate) fn to_cvalue(self, fx: &mut FunctionCx<'_, 'tcx, impl Backend>) -> CValue<'tcx> {
332 let layout = self.layout();
334 CPlaceInner::Var(var) => {
335 let val = fx.bcx.use_var(mir_var(var));
336 fx.bcx.set_val_label(val, cranelift_codegen::ir::ValueLabel::from_u32(var.as_u32()));
337 CValue::by_val(val, layout)
339 CPlaceInner::Addr(ptr, extra) => {
340 if let Some(extra) = extra {
341 CValue::by_ref_unsized(ptr, extra, layout)
343 CValue::by_ref(ptr, layout)
346 CPlaceInner::NoPlace => CValue::by_ref(
347 Pointer::const_addr(fx, i64::try_from(self.layout.align.pref.bytes()).unwrap()),
353 pub(crate) fn to_ptr(self, fx: &mut FunctionCx<'_, 'tcx, impl Backend>) -> Pointer {
354 match self.to_ptr_maybe_unsized(fx) {
356 (_, Some(_)) => bug!("Expected sized cplace, found {:?}", self),
360 pub(crate) fn to_ptr_maybe_unsized(
362 fx: &mut FunctionCx<'_, 'tcx, impl Backend>,
363 ) -> (Pointer, Option<Value>) {
365 CPlaceInner::Addr(ptr, extra) => (ptr, extra),
366 CPlaceInner::NoPlace => {
368 Pointer::const_addr(fx, i64::try_from(self.layout.align.pref.bytes()).unwrap()),
372 CPlaceInner::Var(_) => bug!("Expected CPlace::Addr, found CPlace::Var"),
376 pub(crate) fn write_cvalue(self, fx: &mut FunctionCx<'_, 'tcx, impl Backend>, from: CValue<'tcx>) {
377 #[cfg(debug_assertions)]
379 use cranelift_codegen::cursor::{Cursor, CursorPosition};
380 let cur_block = match fx.bcx.cursor().position() {
381 CursorPosition::After(block) => block,
385 fx.bcx.func.layout.last_inst(cur_block).unwrap(),
386 format!("write_cvalue: {:?}: {:?} <- {:?}: {:?}", self.inner(), self.layout().ty, from.0, from.layout().ty),
390 let from_ty = from.layout().ty;
391 let to_ty = self.layout().ty;
393 fn assert_assignable<'tcx>(
394 fx: &FunctionCx<'_, 'tcx, impl Backend>,
398 match (&from_ty.kind, &to_ty.kind) {
399 (ty::Ref(_, t, Mutability::Not), ty::Ref(_, u, Mutability::Not))
400 | (ty::Ref(_, t, Mutability::Mut), ty::Ref(_, u, Mutability::Not))
401 | (ty::Ref(_, t, Mutability::Mut), ty::Ref(_, u, Mutability::Mut)) => {
402 assert_assignable(fx, t, u);
403 // &mut T -> &T is allowed
404 // &'a T -> &'b T is allowed
406 (ty::Ref(_, _, Mutability::Not), ty::Ref(_, _, Mutability::Mut)) => panic!(
407 "Cant assign value of type {} to place of type {}",
410 (ty::FnPtr(_), ty::FnPtr(_)) => {
411 let from_sig = fx.tcx.normalize_erasing_late_bound_regions(
412 ParamEnv::reveal_all(),
413 &from_ty.fn_sig(fx.tcx),
415 let to_sig = fx.tcx.normalize_erasing_late_bound_regions(
416 ParamEnv::reveal_all(),
417 &to_ty.fn_sig(fx.tcx),
421 "Can't write fn ptr with incompatible sig {:?} to place with sig {:?}\n\n{:#?}",
422 from_sig, to_sig, fx,
424 // fn(&T) -> for<'l> fn(&'l T) is allowed
426 (ty::Dynamic(from_traits, _), ty::Dynamic(to_traits, _)) => {
429 .normalize_erasing_late_bound_regions(ParamEnv::reveal_all(), from_traits);
432 .normalize_erasing_late_bound_regions(ParamEnv::reveal_all(), to_traits);
434 from_traits, to_traits,
435 "Can't write trait object of incompatible traits {:?} to place with traits {:?}\n\n{:#?}",
436 from_traits, to_traits, fx,
438 // dyn for<'r> Trait<'r> -> dyn Trait<'_> is allowed
444 "Can't write value with incompatible type {:?} to place with type {:?}\n\n{:#?}",
453 assert_assignable(fx, from_ty, to_ty);
455 let dst_layout = self.layout();
456 let to_ptr = match self.inner {
457 CPlaceInner::Var(var) => {
458 let data = from.load_scalar(fx);
459 fx.bcx.set_val_label(data, cranelift_codegen::ir::ValueLabel::from_u32(var.as_u32()));
460 fx.bcx.def_var(mir_var(var), data);
463 CPlaceInner::Addr(ptr, None) => ptr,
464 CPlaceInner::NoPlace => {
465 if dst_layout.abi != Abi::Uninhabited {
466 assert_eq!(dst_layout.size.bytes(), 0, "{:?}", dst_layout);
470 CPlaceInner::Addr(_, Some(_)) => bug!("Can't write value to unsized place {:?}", self),
473 match self.layout().abi {
474 // FIXME make Abi::Vector work too
476 let val = from.load_scalar(fx);
477 to_ptr.store(fx, val, MemFlags::new());
480 Abi::ScalarPair(ref a_scalar, ref b_scalar) => {
481 let (value, extra) = from.load_scalar_pair(fx);
482 let b_offset = scalar_pair_calculate_b_offset(fx.tcx, a_scalar, b_scalar);
483 to_ptr.store(fx, value, MemFlags::new());
484 to_ptr.offset(fx, b_offset).store(fx, extra, MemFlags::new());
491 CValueInner::ByVal(val) => {
492 to_ptr.store(fx, val, MemFlags::new());
494 CValueInner::ByValPair(_, _) => {
496 "Non ScalarPair abi {:?} for ByValPair CValue",
500 CValueInner::ByRef(from_ptr, None) => {
501 let from_addr = from_ptr.get_addr(fx);
502 let to_addr = to_ptr.get_addr(fx);
503 let src_layout = from.1;
504 let size = dst_layout.size.bytes();
505 let src_align = src_layout.align.abi.bytes() as u8;
506 let dst_align = dst_layout.align.abi.bytes() as u8;
507 fx.bcx.emit_small_memory_copy(
508 fx.module.target_config(),
517 CValueInner::ByRef(_, Some(_)) => todo!(),
521 pub(crate) fn place_field(
523 fx: &mut FunctionCx<'_, 'tcx, impl Backend>,
526 let layout = self.layout();
527 let (base, extra) = self.to_ptr_maybe_unsized(fx);
529 let (field_ptr, field_layout) = codegen_field(fx, base, extra, layout, field);
530 if field_layout.is_unsized() {
531 CPlace::for_ptr_with_extra(field_ptr, extra.unwrap(), field_layout)
533 CPlace::for_ptr(field_ptr, field_layout)
537 pub(crate) fn place_index(
539 fx: &mut FunctionCx<'_, 'tcx, impl Backend>,
542 let (elem_layout, ptr) = match self.layout().ty.kind {
543 ty::Array(elem_ty, _) => (fx.layout_of(elem_ty), self.to_ptr(fx)),
544 ty::Slice(elem_ty) => (fx.layout_of(elem_ty), self.to_ptr_maybe_unsized(fx).0),
545 _ => bug!("place_index({:?})", self.layout().ty),
551 .imul_imm(index, elem_layout.size.bytes() as i64);
553 CPlace::for_ptr(ptr.offset_value(fx, offset), elem_layout)
556 pub(crate) fn place_deref(self, fx: &mut FunctionCx<'_, 'tcx, impl Backend>) -> CPlace<'tcx> {
557 let inner_layout = fx.layout_of(self.layout().ty.builtin_deref(true).unwrap().ty);
558 if has_ptr_meta(fx.tcx, inner_layout.ty) {
559 let (addr, extra) = self.to_cvalue(fx).load_scalar_pair(fx);
560 CPlace::for_ptr_with_extra(Pointer::new(addr), extra, inner_layout)
562 CPlace::for_ptr(Pointer::new(self.to_cvalue(fx).load_scalar(fx)), inner_layout)
566 pub(crate) fn write_place_ref(self, fx: &mut FunctionCx<'_, 'tcx, impl Backend>, dest: CPlace<'tcx>) {
567 if has_ptr_meta(fx.tcx, self.layout().ty) {
568 let (ptr, extra) = self.to_ptr_maybe_unsized(fx);
569 let ptr = CValue::by_val_pair(
571 extra.expect("unsized type without metadata"),
574 dest.write_cvalue(fx, ptr);
576 let ptr = CValue::by_val(self.to_ptr(fx).get_addr(fx), dest.layout());
577 dest.write_cvalue(fx, ptr);
581 pub(crate) fn unchecked_cast_to(self, layout: TyAndLayout<'tcx>) -> Self {
582 assert!(!self.layout().is_unsized());
584 CPlaceInner::NoPlace => {
585 assert!(layout.size.bytes() == 0);
595 pub(crate) fn downcast_variant(
597 fx: &FunctionCx<'_, 'tcx, impl Backend>,
600 let layout = self.layout().for_variant(fx, variant);
601 self.unchecked_cast_to(layout)