3 fn codegen_field<'a, 'tcx: 'a>(
4 fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
6 layout: TyLayout<'tcx>,
8 ) -> (Value, TyLayout<'tcx>) {
9 let field_offset = layout.fields.offset(field.index());
10 let field_ty = layout.field(&*fx, field.index());
11 if field_offset.bytes() > 0 {
13 fx.bcx.ins().iadd_imm(base, field_offset.bytes() as i64),
21 fn scalar_pair_calculate_b_offset(tcx: TyCtxt<'_>, a_scalar: &Scalar, b_scalar: &Scalar) -> i32 {
22 let b_offset = a_scalar.value.size(&tcx).align_to(b_scalar.value.align(&tcx).abi);
23 b_offset.bytes().try_into().unwrap()
27 #[derive(Debug, Copy, Clone)]
28 pub struct CValue<'tcx>(CValueInner, TyLayout<'tcx>);
30 #[derive(Debug, Copy, Clone)]
34 ByValPair(Value, Value),
37 fn store_scalar<'a, 'tcx: 'a>(fx: &mut FunctionCx<'a, 'tcx, impl Backend>, value: Value, addr: Value, offset: i32) {
38 if fx.bcx.func.dfg.value_type(value) == types::I128 {
39 let (a, b) = fx.bcx.ins().isplit(value);
40 fx.bcx.ins().store(MemFlags::new(), a, addr, offset);
41 fx.bcx.ins().store(MemFlags::new(), b, addr, offset + 8);
43 fx.bcx.ins().store(MemFlags::new(), value, addr, offset);
47 impl<'tcx> CValue<'tcx> {
48 pub fn by_ref(value: Value, layout: TyLayout<'tcx>) -> CValue<'tcx> {
49 CValue(CValueInner::ByRef(value), layout)
52 pub fn by_val(value: Value, layout: TyLayout<'tcx>) -> CValue<'tcx> {
53 CValue(CValueInner::ByVal(value), layout)
56 pub fn by_val_pair(value: Value, extra: Value, layout: TyLayout<'tcx>) -> CValue<'tcx> {
57 CValue(CValueInner::ByValPair(value, extra), layout)
60 pub fn layout(&self) -> TyLayout<'tcx> {
64 pub fn force_stack<'a>(self, fx: &mut FunctionCx<'a, 'tcx, impl Backend>) -> Value
70 CValueInner::ByRef(value) => value,
71 CValueInner::ByVal(_) | CValueInner::ByValPair(_, _) => {
72 let cplace = CPlace::new_stack_slot(fx, layout.ty);
73 cplace.write_cvalue(fx, self);
79 /// Load a value with layout.abi of scalar
80 pub fn load_scalar<'a>(self, fx: &mut FunctionCx<'a, 'tcx, impl Backend>) -> Value
86 CValueInner::ByRef(addr) => {
87 let scalar = match layout.abi {
88 layout::Abi::Scalar(ref scalar) => scalar.clone(),
91 let clif_ty = scalar_to_clif_type(fx.tcx, scalar);
92 fx.bcx.ins().load(clif_ty, MemFlags::new(), addr, 0)
94 CValueInner::ByVal(value) => value,
95 CValueInner::ByValPair(_, _) => bug!("Please use load_scalar_pair for ByValPair"),
99 /// Load a value pair with layout.abi of scalar pair
100 pub fn load_scalar_pair<'a>(self, fx: &mut FunctionCx<'a, 'tcx, impl Backend>) -> (Value, Value)
106 CValueInner::ByRef(addr) => {
107 let (a_scalar, b_scalar) = match &layout.abi {
108 layout::Abi::ScalarPair(a, b) => (a, b),
111 let b_offset = scalar_pair_calculate_b_offset(fx.tcx, a_scalar, b_scalar);
112 let clif_ty1 = scalar_to_clif_type(fx.tcx, a_scalar.clone());
113 let clif_ty2 = scalar_to_clif_type(fx.tcx, b_scalar.clone());
114 let val1 = fx.bcx.ins().load(clif_ty1, MemFlags::new(), addr, 0);
115 let val2 = fx.bcx.ins().load(
123 CValueInner::ByVal(_) => bug!("Please use load_scalar for ByVal"),
124 CValueInner::ByValPair(val1, val2) => (val1, val2),
128 pub fn value_field<'a>(
130 fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
137 let base = match self.0 {
138 CValueInner::ByRef(addr) => addr,
139 _ => bug!("place_field for {:?}", self),
142 let (field_ptr, field_layout) = codegen_field(fx, base, layout, field);
143 CValue::by_ref(field_ptr, field_layout)
146 pub fn unsize_value<'a>(self, fx: &mut FunctionCx<'a, 'tcx, impl Backend>, dest: CPlace<'tcx>) {
147 crate::unsize::coerce_unsized_into(fx, self, dest);
150 pub fn const_val<'a>(
151 fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
158 let clif_ty = fx.clif_type(ty).unwrap();
159 let layout = fx.layout_of(ty);
160 let val = if clif_ty == types::I128 {
161 // FIXME don't assume little-endian arch
162 let lsb = fx.bcx.ins().iconst(types::I64, const_val);
163 let msb = fx.bcx.ins().iconst(types::I64, 0);
164 fx.bcx.ins().iconcat(lsb, msb)
166 fx.bcx.ins().iconst(clif_ty, const_val)
168 CValue::by_val(val, layout)
171 pub fn unchecked_cast_to(self, layout: TyLayout<'tcx>) -> Self {
172 CValue(self.0, layout)
176 /// A place where you can write a value to or read a value from
177 #[derive(Debug, Copy, Clone)]
178 pub enum CPlace<'tcx> {
179 Var(Local, TyLayout<'tcx>),
180 Addr(Value, Option<Value>, TyLayout<'tcx>),
181 Stack(StackSlot, TyLayout<'tcx>),
182 NoPlace(TyLayout<'tcx>),
185 impl<'a, 'tcx: 'a> CPlace<'tcx> {
186 pub fn layout(&self) -> TyLayout<'tcx> {
188 CPlace::Var(_, layout)
189 | CPlace::Addr(_, _, layout)
190 | CPlace::Stack(_, layout)
191 | CPlace::NoPlace(layout) => layout,
195 pub fn no_place(layout: TyLayout<'tcx>) -> CPlace<'tcx> {
196 CPlace::NoPlace(layout)
199 pub fn new_stack_slot(
200 fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
203 let layout = fx.layout_of(ty);
204 assert!(!layout.is_unsized());
205 if layout.size.bytes() == 0 {
206 return CPlace::NoPlace(layout);
209 let stack_slot = fx.bcx.create_stack_slot(StackSlotData {
210 kind: StackSlotKind::ExplicitSlot,
211 size: layout.size.bytes() as u32,
214 CPlace::Stack(stack_slot, layout)
218 fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
220 layout: TyLayout<'tcx>,
223 .declare_var(mir_var(local), fx.clif_type(layout.ty).unwrap());
224 CPlace::Var(local, layout)
227 pub fn for_addr(addr: Value, layout: TyLayout<'tcx>) -> CPlace<'tcx> {
228 CPlace::Addr(addr, None, layout)
231 pub fn for_addr_with_extra(addr: Value, extra: Value, layout: TyLayout<'tcx>) -> CPlace<'tcx> {
232 CPlace::Addr(addr, Some(extra), layout)
235 pub fn to_cvalue(self, fx: &mut FunctionCx<'a, 'tcx, impl Backend>) -> CValue<'tcx> {
237 CPlace::Var(var, layout) => CValue::by_val(fx.bcx.use_var(mir_var(var)), layout),
238 CPlace::Addr(addr, extra, layout) => {
239 assert!(extra.is_none(), "unsized values are not yet supported");
240 CValue::by_ref(addr, layout)
242 CPlace::Stack(stack_slot, layout) => CValue::by_ref(
243 fx.bcx.ins().stack_addr(fx.pointer_type, stack_slot, 0),
246 CPlace::NoPlace(layout) => CValue::by_ref(
249 .iconst(fx.pointer_type, fx.pointer_type.bytes() as i64),
255 pub fn to_addr(self, fx: &mut FunctionCx<'a, 'tcx, impl Backend>) -> Value {
256 match self.to_addr_maybe_unsized(fx) {
257 (addr, None) => addr,
258 (_, Some(_)) => bug!("Expected sized cplace, found {:?}", self),
262 pub fn to_addr_maybe_unsized(
264 fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
265 ) -> (Value, Option<Value>) {
267 CPlace::Addr(addr, extra, _layout) => (addr, extra),
268 CPlace::Stack(stack_slot, _layout) => (
269 fx.bcx.ins().stack_addr(fx.pointer_type, stack_slot, 0),
272 CPlace::NoPlace(_) => (fx.bcx.ins().iconst(fx.pointer_type, 45), None),
273 CPlace::Var(_, _) => bug!("Expected CPlace::Addr, found CPlace::Var"),
277 pub fn write_cvalue(self, fx: &mut FunctionCx<'a, 'tcx, impl Backend>, from: CValue<'tcx>) {
278 use rustc::hir::Mutability::*;
280 let from_ty = from.layout().ty;
281 let to_ty = self.layout().ty;
283 fn assert_assignable<'a, 'tcx: 'a>(fx: &FunctionCx<'a, 'tcx, impl Backend>, from_ty: Ty<'tcx>, to_ty: Ty<'tcx>) {
284 match (&from_ty.sty, &to_ty.sty) {
285 (ty::Ref(_, t, MutImmutable), ty::Ref(_, u, MutImmutable))
286 | (ty::Ref(_, t, MutMutable), ty::Ref(_, u, MutImmutable))
287 | (ty::Ref(_, t, MutMutable), ty::Ref(_, u, MutMutable)) => {
288 assert_assignable(fx, t, u);
289 // &mut T -> &T is allowed
290 // &'a T -> &'b T is allowed
292 (ty::Ref(_, _, MutImmutable), ty::Ref(_, _, MutMutable)) => {
293 panic!("Cant assign value of type {} to place of type {}", from_ty, to_ty)
295 (ty::FnPtr(_), ty::FnPtr(_)) => {
296 let from_sig = fx.tcx.normalize_erasing_late_bound_regions(
297 ParamEnv::reveal_all(),
298 &from_ty.fn_sig(fx.tcx),
300 let to_sig = fx.tcx.normalize_erasing_late_bound_regions(
301 ParamEnv::reveal_all(),
302 &to_ty.fn_sig(fx.tcx),
306 "Can't write fn ptr with incompatible sig {:?} to place with sig {:?}\n\n{:#?}",
307 from_sig, to_sig, fx,
309 // fn(&T) -> for<'l> fn(&'l T) is allowed
311 (ty::Dynamic(from_traits, _), ty::Dynamic(to_traits, _)) => {
312 let from_traits = fx.tcx.normalize_erasing_late_bound_regions(
313 ParamEnv::reveal_all(),
316 let to_traits = fx.tcx.normalize_erasing_late_bound_regions(
317 ParamEnv::reveal_all(),
321 from_traits, to_traits,
322 "Can't write trait object of incompatible traits {:?} to place with traits {:?}\n\n{:#?}",
323 from_traits, to_traits, fx,
325 // dyn for<'r> Trait<'r> -> dyn Trait<'_> is allowed
331 "Can't write value with incompatible type {:?} to place with type {:?}\n\n{:#?}",
340 assert_assignable(fx, from_ty, to_ty);
342 let (addr, dst_layout) = match self {
343 CPlace::Var(var, _) => {
344 let data = from.load_scalar(fx);
345 fx.bcx.def_var(mir_var(var), data);
348 CPlace::Addr(addr, None, dst_layout) => (addr, dst_layout),
349 CPlace::Stack(stack_slot, dst_layout) => (
350 fx.bcx.ins().stack_addr(fx.pointer_type, stack_slot, 0),
353 CPlace::NoPlace(layout) => {
354 if layout.abi != Abi::Uninhabited {
355 assert_eq!(layout.size.bytes(), 0, "{:?}", layout);
359 CPlace::Addr(_, _, _) => bug!("Can't write value to unsized place {:?}", self),
363 CValueInner::ByVal(val) => {
364 store_scalar(fx, val, addr, 0);
366 CValueInner::ByValPair(value, extra) => {
367 match dst_layout.abi {
368 Abi::ScalarPair(ref a_scalar, ref b_scalar) => {
369 let b_offset = scalar_pair_calculate_b_offset(fx.tcx, a_scalar, b_scalar);
370 store_scalar(fx, value, addr, 0);
379 "Non ScalarPair abi {:?} for ByValPair CValue",
384 CValueInner::ByRef(from_addr) => {
385 let src_layout = from.1;
386 let size = dst_layout.size.bytes();
387 let src_align = src_layout.align.abi.bytes() as u8;
388 let dst_align = dst_layout.align.abi.bytes() as u8;
389 fx.bcx.emit_small_memcpy(
390 fx.module.target_config(),
403 fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
406 let layout = self.layout();
407 let (base, extra) = self.to_addr_maybe_unsized(fx);
409 let (field_ptr, field_layout) = codegen_field(fx, base, layout, field);
410 let extra = if field_layout.is_unsized() {
411 assert!(extra.is_some());
416 CPlace::Addr(field_ptr, extra, field_layout)
421 fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
424 let (elem_layout, addr) = match self.layout().ty.sty {
425 ty::Array(elem_ty, _) => (fx.layout_of(elem_ty), self.to_addr(fx)),
426 ty::Slice(elem_ty) => (fx.layout_of(elem_ty), self.to_addr_maybe_unsized(fx).0),
427 _ => bug!("place_index({:?})", self.layout().ty),
433 .imul_imm(index, elem_layout.size.bytes() as i64);
435 CPlace::Addr(fx.bcx.ins().iadd(addr, offset), None, elem_layout)
438 pub fn place_deref(self, fx: &mut FunctionCx<'a, 'tcx, impl Backend>) -> CPlace<'tcx> {
439 let inner_layout = fx.layout_of(self.layout().ty.builtin_deref(true).unwrap().ty);
440 if !inner_layout.is_unsized() {
441 CPlace::Addr(self.to_cvalue(fx).load_scalar(fx), None, inner_layout)
443 let (addr, extra) = self.to_cvalue(fx).load_scalar_pair(fx);
444 CPlace::Addr(addr, Some(extra), inner_layout)
448 pub fn write_place_ref(self, fx: &mut FunctionCx<'a, 'tcx, impl Backend>, dest: CPlace<'tcx>) {
449 if !self.layout().is_unsized() {
450 let ptr = CValue::by_val(self.to_addr(fx), dest.layout());
451 dest.write_cvalue(fx, ptr);
453 let (value, extra) = self.to_addr_maybe_unsized(fx);
454 let ptr = CValue::by_val_pair(value, extra.expect("unsized type without metadata"), dest.layout());
455 dest.write_cvalue(fx, ptr);
459 pub fn unchecked_cast_to(self, layout: TyLayout<'tcx>) -> Self {
460 assert!(!self.layout().is_unsized());
462 CPlace::Var(var, _) => CPlace::Var(var, layout),
463 CPlace::Addr(addr, extra, _) => CPlace::Addr(addr, extra, layout),
464 CPlace::Stack(stack_slot, _) => CPlace::Stack(stack_slot, layout),
465 CPlace::NoPlace(_) => {
466 assert!(layout.size.bytes() == 0);
467 CPlace::NoPlace(layout)
472 pub fn downcast_variant(
474 fx: &FunctionCx<'a, 'tcx, impl Backend>,
477 let layout = self.layout().for_variant(fx, variant);
478 self.unchecked_cast_to(layout)