src/abi.rs

   1 use std::iter;
   2
   3 use crate::rustc::hir;
   4 use crate::rustc_target::spec::abi::Abi;
   5
   6 use crate::prelude::*;
   7
   8 #[derive(Debug)]
   9 enum PassMode {
  10     NoPass,
  11     ByVal(Type),
  12     ByRef,
  13 }
  14
  15 impl PassMode {
  16     fn get_param_ty(self, fx: &FunctionCx<impl Backend>) -> Type {
  17         match self {
  18             PassMode::NoPass => unimplemented!("pass mode nopass"),
  19             PassMode::ByVal(cton_type) => cton_type,
  20             PassMode::ByRef => fx.module.pointer_type(),
  21         }
  22     }
  23 }
  24
  25 fn get_pass_mode<'a, 'tcx: 'a>(
  26     tcx: TyCtxt<'a, 'tcx, 'tcx>,
  27     abi: Abi,
  28     ty: Ty<'tcx>,
  29     is_return: bool,
  30 ) -> PassMode {
  31     assert!(
  32         !tcx.layout_of(ParamEnv::reveal_all().and(ty))
  33             .unwrap()
  34             .is_unsized()
  35     );
  36     if let ty::Never = ty.sty {
  37         if is_return {
  38             PassMode::NoPass
  39         } else {
  40             PassMode::ByRef
  41         }
  42     } else if ty.sty == tcx.mk_unit().sty {
  43         if is_return {
  44             PassMode::NoPass
  45         } else {
  46             PassMode::ByRef
  47         }
  48     } else if let Some(ret_ty) = crate::common::cton_type_from_ty(tcx, ty) {
  49         PassMode::ByVal(ret_ty)
  50     } else {
  51         if abi == Abi::C {
  52             unimpl!(
  53                 "Non scalars are not yet supported for \"C\" abi ({:?}) is_return: {:?}",
  54                 ty,
  55                 is_return
  56             );
  57         }
  58         PassMode::ByRef
  59     }
  60 }
  61
  62 fn adjust_arg_for_abi<'a, 'tcx: 'a>(
  63     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
  64     sig: FnSig<'tcx>,
  65     arg: CValue<'tcx>,
  66 ) -> Value {
  67     match get_pass_mode(fx.tcx, sig.abi, arg.layout().ty, false) {
  68         PassMode::NoPass => unimplemented!("pass mode nopass"),
  69         PassMode::ByVal(_) => arg.load_value(fx),
  70         PassMode::ByRef => arg.force_stack(fx),
  71     }
  72 }
  73
  74 pub fn cton_sig_from_fn_ty<'a, 'tcx: 'a>(
  75     tcx: TyCtxt<'a, 'tcx, 'tcx>,
  76     fn_ty: Ty<'tcx>,
  77 ) -> Signature {
  78     let sig = ty_fn_sig(tcx, fn_ty);
  79     assert!(!sig.variadic, "Variadic function are not yet supported");
  80     let (call_conv, inputs, output): (CallConv, Vec<Ty>, Ty) = match sig.abi {
  81         Abi::Rust => (CallConv::Fast, sig.inputs().to_vec(), sig.output()),
  82         Abi::C => (CallConv::SystemV, sig.inputs().to_vec(), sig.output()),
  83         Abi::RustCall => {
  84             assert_eq!(sig.inputs().len(), 2);
  85             let extra_args = match sig.inputs().last().unwrap().sty {
  86                 ty::Tuple(ref tupled_arguments) => tupled_arguments,
  87                 _ => bug!("argument to function with \"rust-call\" ABI is not a tuple"),
  88             };
  89             let mut inputs: Vec<Ty> = vec![sig.inputs()[0]];
  90             inputs.extend(extra_args.into_iter());
  91             (CallConv::Fast, inputs, sig.output())
  92         }
  93         Abi::System => bug!("system abi should be selected elsewhere"),
  94         Abi::RustIntrinsic => (CallConv::SystemV, sig.inputs().to_vec(), sig.output()),
  95         _ => unimplemented!("unsupported abi {:?}", sig.abi),
  96     };
  97
  98     let inputs = inputs
  99         .into_iter()
 100         .filter_map(|ty| match get_pass_mode(tcx, sig.abi, ty, false) {
 101             PassMode::ByVal(cton_ty) => Some(cton_ty),
 102             PassMode::NoPass => unimplemented!("pass mode nopass"),
 103             PassMode::ByRef => Some(pointer_ty(tcx)),
 104         });
 105
 106     let (params, returns) = match get_pass_mode(tcx, sig.abi, output, true) {
 107         PassMode::NoPass => (inputs.map(AbiParam::new).collect(), vec![]),
 108         PassMode::ByVal(ret_ty) => (
 109             inputs.map(AbiParam::new).collect(),
 110             vec![AbiParam::new(ret_ty)],
 111         ),
 112         PassMode::ByRef => {
 113             (
 114                 Some(pointer_ty(tcx)) // First param is place to put return val
 115                     .into_iter()
 116                     .chain(inputs)
 117                     .map(AbiParam::new)
 118                     .collect(),
 119                 vec![],
 120             )
 121         }
 122     };
 123
 124     Signature {
 125         params,
 126         returns,
 127         call_conv,
 128     }
 129 }
 130
 131 fn ty_fn_sig<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, ty: Ty<'tcx>) -> ty::FnSig<'tcx> {
 132     let sig = match ty.sty {
 133         ty::FnDef(..) |
 134         // Shims currently have type TyFnPtr. Not sure this should remain.
 135         ty::FnPtr(_) => ty.fn_sig(tcx),
 136         ty::Closure(def_id, substs) => {
 137             let sig = substs.closure_sig(def_id, tcx);
 138
 139             let env_ty = tcx.closure_env_ty(def_id, substs).unwrap();
 140             sig.map_bound(|sig| tcx.mk_fn_sig(
 141                 iter::once(*env_ty.skip_binder()).chain(sig.inputs().iter().cloned()),
 142                 sig.output(),
 143                 sig.variadic,
 144                 sig.unsafety,
 145                 sig.abi
 146             ))
 147         }
 148         ty::Generator(def_id, substs, _) => {
 149             let sig = substs.poly_sig(def_id, tcx);
 150
 151             let env_region = ty::ReLateBound(ty::INNERMOST, ty::BrEnv);
 152             let env_ty = tcx.mk_mut_ref(tcx.mk_region(env_region), ty);
 153
 154             sig.map_bound(|sig| {
 155                 let state_did = tcx.lang_items().gen_state().unwrap();
 156                 let state_adt_ref = tcx.adt_def(state_did);
 157                 let state_substs = tcx.intern_substs(&[
 158                     sig.yield_ty.into(),
 159                     sig.return_ty.into(),
 160                 ]);
 161                 let ret_ty = tcx.mk_adt(state_adt_ref, state_substs);
 162
 163                 tcx.mk_fn_sig(iter::once(env_ty),
 164                     ret_ty,
 165                     false,
 166                     hir::Unsafety::Normal,
 167                     Abi::Rust
 168                 )
 169             })
 170         }
 171         _ => bug!("unexpected type {:?} to ty_fn_sig", ty)
 172     };
 173     tcx.normalize_erasing_late_bound_regions(ParamEnv::reveal_all(), &sig)
 174 }
 175
 176 pub fn get_function_name_and_sig<'a, 'tcx>(
 177     tcx: TyCtxt<'a, 'tcx, 'tcx>,
 178     inst: Instance<'tcx>,
 179 ) -> (String, Signature) {
 180     assert!(!inst.substs.needs_infer() && !inst.substs.has_param_types());
 181     let fn_ty = inst.ty(tcx);
 182     let sig = cton_sig_from_fn_ty(tcx, fn_ty);
 183     (tcx.symbol_name(inst).as_str().to_string(), sig)
 184 }
 185
 186 impl<'a, 'tcx: 'a, B: Backend + 'a> FunctionCx<'a, 'tcx, B> {
 187     /// Instance must be monomorphized
 188     pub fn get_function_id(&mut self, inst: Instance<'tcx>) -> FuncId {
 189         let (name, sig) = get_function_name_and_sig(self.tcx, inst);
 190         self.module
 191             .declare_function(&name, Linkage::Import, &sig)
 192             .unwrap()
 193     }
 194
 195     /// Instance must be monomorphized
 196     pub fn get_function_ref(&mut self, inst: Instance<'tcx>) -> FuncRef {
 197         let func_id = self.get_function_id(inst);
 198         self.module
 199             .declare_func_in_func(func_id, &mut self.bcx.func)
 200     }
 201
 202     fn lib_call(
 203         &mut self,
 204         name: &str,
 205         input_tys: Vec<types::Type>,
 206         output_ty: Option<types::Type>,
 207         args: &[Value],
 208     ) -> Option<Value> {
 209         let sig = Signature {
 210             params: input_tys.iter().cloned().map(AbiParam::new).collect(),
 211             returns: output_ty
 212                 .map(|output_ty| vec![AbiParam::new(output_ty)])
 213                 .unwrap_or(Vec::new()),
 214             call_conv: CallConv::SystemV,
 215         };
 216         let func_id = self
 217             .module
 218             .declare_function(&name, Linkage::Import, &sig)
 219             .unwrap();
 220         let func_ref = self
 221             .module
 222             .declare_func_in_func(func_id, &mut self.bcx.func);
 223         let call_inst = self.bcx.ins().call(func_ref, args);
 224         if output_ty.is_none() {
 225             return None;
 226         }
 227         let results = self.bcx.inst_results(call_inst);
 228         assert_eq!(results.len(), 1);
 229         Some(results[0])
 230     }
 231
 232     pub fn easy_call(
 233         &mut self,
 234         name: &str,
 235         args: &[CValue<'tcx>],
 236         return_ty: Ty<'tcx>,
 237     ) -> CValue<'tcx> {
 238         let (input_tys, args): (Vec<_>, Vec<_>) = args
 239             .into_iter()
 240             .map(|arg| {
 241                 (
 242                     self.cton_type(arg.layout().ty).unwrap(),
 243                     arg.load_value(self),
 244                 )
 245             }).unzip();
 246         let return_layout = self.layout_of(return_ty);
 247         let return_ty = if let ty::Tuple(tup) = return_ty.sty {
 248             if !tup.is_empty() {
 249                 bug!("easy_call( (...) -> <non empty tuple> ) is not allowed");
 250             }
 251             None
 252         } else {
 253             Some(self.cton_type(return_ty).unwrap())
 254         };
 255         if let Some(val) = self.lib_call(name, input_tys, return_ty, &args) {
 256             CValue::ByVal(val, return_layout)
 257         } else {
 258             CValue::ByRef(
 259                 self.bcx.ins().iconst(self.module.pointer_type(), 0),
 260                 return_layout,
 261             )
 262         }
 263     }
 264
 265     fn self_sig(&self) -> FnSig<'tcx> {
 266         ty_fn_sig(self.tcx, self.instance.ty(self.tcx))
 267     }
 268
 269     fn return_type(&self) -> Ty<'tcx> {
 270         self.self_sig().output()
 271     }
 272 }
 273
 274 pub fn codegen_fn_prelude<'a, 'tcx: 'a>(
 275     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 276     start_ebb: Ebb,
 277 ) {
 278     let ssa_analyzed = crate::analyze::analyze(fx);
 279
 280     let ret_layout = fx.layout_of(fx.return_type());
 281     let output_pass_mode = get_pass_mode(fx.tcx, fx.self_sig().abi, fx.return_type(), true);
 282     let ret_param = match output_pass_mode {
 283         PassMode::NoPass => None,
 284         PassMode::ByVal(_) => None,
 285         PassMode::ByRef => Some(fx.bcx.append_ebb_param(start_ebb, fx.module.pointer_type())),
 286     };
 287
 288     enum ArgKind {
 289         Normal(Value),
 290         Spread(Vec<Value>),
 291     }
 292
 293     let func_params = fx
 294         .mir
 295         .args_iter()
 296         .map(|local| {
 297             let arg_ty = fx.monomorphize(&fx.mir.local_decls[local].ty);
 298
 299             // Adapted from https://github.com/rust-lang/rust/blob/145155dc96757002c7b2e9de8489416e2fdbbd57/src/librustc_codegen_llvm/mir/mod.rs#L442-L482
 300             if Some(local) == fx.mir.spread_arg {
 301                 // This argument (e.g. the last argument in the "rust-call" ABI)
 302                 // is a tuple that was spread at the ABI level and now we have
 303                 // to reconstruct it into a tuple local variable, from multiple
 304                 // individual function arguments.
 305
 306                 let tupled_arg_tys = match arg_ty.sty {
 307                     ty::Tuple(ref tys) => tys,
 308                     _ => bug!("spread argument isn't a tuple?! but {:?}", arg_ty),
 309                 };
 310
 311                 let mut ebb_params = Vec::new();
 312                 for arg_ty in tupled_arg_tys.iter() {
 313                     let cton_type =
 314                         get_pass_mode(fx.tcx, fx.self_sig().abi, arg_ty, false).get_param_ty(fx);
 315                     ebb_params.push(fx.bcx.append_ebb_param(start_ebb, cton_type));
 316                 }
 317
 318                 (local, ArgKind::Spread(ebb_params), arg_ty)
 319             } else {
 320                 let cton_type =
 321                     get_pass_mode(fx.tcx, fx.self_sig().abi, arg_ty, false).get_param_ty(fx);
 322                 (
 323                     local,
 324                     ArgKind::Normal(fx.bcx.append_ebb_param(start_ebb, cton_type)),
 325                     arg_ty,
 326                 )
 327             }
 328         }).collect::<Vec<(Local, ArgKind, Ty)>>();
 329
 330     fx.bcx.switch_to_block(start_ebb);
 331
 332     fx.top_nop = Some(fx.bcx.ins().nop());
 333     fx.add_global_comment(format!("ssa {:?}", ssa_analyzed));
 334
 335     match output_pass_mode {
 336         PassMode::NoPass => {
 337             let null = fx.bcx.ins().iconst(fx.module.pointer_type(), 0);
 338             //unimplemented!("pass mode nopass");
 339             fx.local_map.insert(
 340                 RETURN_PLACE,
 341                 CPlace::Addr(null, None, fx.layout_of(fx.return_type())),
 342             );
 343         }
 344         PassMode::ByVal(ret_ty) => {
 345             fx.bcx.declare_var(mir_var(RETURN_PLACE), ret_ty);
 346             fx.local_map
 347                 .insert(RETURN_PLACE, CPlace::Var(RETURN_PLACE, ret_layout));
 348         }
 349         PassMode::ByRef => {
 350             fx.local_map.insert(
 351                 RETURN_PLACE,
 352                 CPlace::Addr(ret_param.unwrap(), None, ret_layout),
 353             );
 354         }
 355     }
 356
 357     for (local, arg_kind, ty) in func_params {
 358         let layout = fx.layout_of(ty);
 359
 360         if let ArgKind::Normal(ebb_param) = arg_kind {
 361             if !ssa_analyzed
 362                 .get(&local)
 363                 .unwrap()
 364                 .contains(crate::analyze::Flags::NOT_SSA)
 365             {
 366                 fx.bcx
 367                     .declare_var(mir_var(local), fx.cton_type(ty).unwrap());
 368                 match get_pass_mode(fx.tcx, fx.self_sig().abi, ty, false) {
 369                     PassMode::NoPass => unimplemented!("pass mode nopass"),
 370                     PassMode::ByVal(_) => fx.bcx.def_var(mir_var(local), ebb_param),
 371                     PassMode::ByRef => {
 372                         let val = CValue::ByRef(ebb_param, fx.layout_of(ty)).load_value(fx);
 373                         fx.bcx.def_var(mir_var(local), val);
 374                     }
 375                 }
 376                 fx.local_map.insert(local, CPlace::Var(local, layout));
 377                 continue;
 378             }
 379         }
 380
 381         let stack_slot = fx.bcx.create_stack_slot(StackSlotData {
 382             kind: StackSlotKind::ExplicitSlot,
 383             size: layout.size.bytes() as u32,
 384             offset: None,
 385         });
 386
 387         let place = CPlace::from_stack_slot(fx, stack_slot, ty);
 388
 389         match arg_kind {
 390             ArgKind::Normal(ebb_param) => match get_pass_mode(fx.tcx, fx.self_sig().abi, ty, false)
 391             {
 392                 PassMode::NoPass => unimplemented!("pass mode nopass"),
 393                 PassMode::ByVal(_) => {
 394                     place.write_cvalue(fx, CValue::ByVal(ebb_param, place.layout()))
 395                 }
 396                 PassMode::ByRef => place.write_cvalue(fx, CValue::ByRef(ebb_param, place.layout())),
 397             },
 398             ArgKind::Spread(ebb_params) => {
 399                 for (i, ebb_param) in ebb_params.into_iter().enumerate() {
 400                     let sub_place = place.place_field(fx, mir::Field::new(i));
 401                     match get_pass_mode(fx.tcx, fx.self_sig().abi, sub_place.layout().ty, false) {
 402                         PassMode::NoPass => unimplemented!("pass mode nopass"),
 403                         PassMode::ByVal(_) => {
 404                             sub_place.write_cvalue(fx, CValue::ByVal(ebb_param, sub_place.layout()))
 405                         }
 406                         PassMode::ByRef => {
 407                             sub_place.write_cvalue(fx, CValue::ByRef(ebb_param, sub_place.layout()))
 408                         }
 409                     }
 410                 }
 411             }
 412         }
 413         fx.local_map.insert(local, place);
 414     }
 415
 416     for local in fx.mir.vars_and_temps_iter() {
 417         let ty = fx.mir.local_decls[local].ty;
 418         let layout = fx.layout_of(ty);
 419
 420         let place = if ssa_analyzed
 421             .get(&local)
 422             .unwrap()
 423             .contains(crate::analyze::Flags::NOT_SSA)
 424         {
 425             let stack_slot = fx.bcx.create_stack_slot(StackSlotData {
 426                 kind: StackSlotKind::ExplicitSlot,
 427                 size: layout.size.bytes() as u32,
 428                 offset: None,
 429             });
 430             CPlace::from_stack_slot(fx, stack_slot, ty)
 431         } else {
 432             fx.bcx
 433                 .declare_var(mir_var(local), fx.cton_type(ty).unwrap());
 434             CPlace::Var(local, layout)
 435         };
 436
 437         fx.local_map.insert(local, place);
 438     }
 439
 440     fx.bcx
 441         .ins()
 442         .jump(*fx.ebb_map.get(&START_BLOCK).unwrap(), &[]);
 443 }
 444
 445 pub fn codegen_terminator_call<'a, 'tcx: 'a>(
 446     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 447     func: &Operand<'tcx>,
 448     args: &[Operand<'tcx>],
 449     destination: &Option<(Place<'tcx>, BasicBlock)>,
 450 ) {
 451     let fn_ty = fx.monomorphize(&func.ty(&fx.mir.local_decls, fx.tcx));
 452     let sig = ty_fn_sig(fx.tcx, fn_ty);
 453
 454     // Unpack arguments tuple for closures
 455     let args = if sig.abi == Abi::RustCall {
 456         assert_eq!(args.len(), 2, "rust-call abi requires two arguments");
 457         let self_arg = trans_operand(fx, &args[0]);
 458         let pack_arg = trans_operand(fx, &args[1]);
 459         let mut args = Vec::new();
 460         args.push(self_arg);
 461         match pack_arg.layout().ty.sty {
 462             ty::Tuple(ref tupled_arguments) => {
 463                 for (i, _) in tupled_arguments.iter().enumerate() {
 464                     args.push(pack_arg.value_field(fx, mir::Field::new(i)));
 465                 }
 466             }
 467             _ => bug!("argument to function with \"rust-call\" ABI is not a tuple"),
 468         }
 469         args
 470     } else {
 471         args.into_iter()
 472             .map(|arg| trans_operand(fx, arg))
 473             .collect::<Vec<_>>()
 474     };
 475
 476     let destination = destination
 477         .as_ref()
 478         .map(|&(ref place, bb)| (trans_place(fx, place), bb));
 479
 480     if !codegen_intrinsic_call(fx, fn_ty, &args, destination) {
 481         codegen_call_inner(
 482             fx,
 483             Some(func),
 484             fn_ty,
 485             args,
 486             destination.map(|(place, _)| place),
 487         );
 488
 489         if let Some((_, dest)) = destination {
 490             let ret_ebb = fx.get_ebb(dest);
 491             fx.bcx.ins().jump(ret_ebb, &[]);
 492         } else {
 493             fx.bcx.ins().trap(TrapCode::User(!0));
 494         }
 495     }
 496 }
 497
 498 pub fn codegen_call_inner<'a, 'tcx: 'a>(
 499     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 500     func: Option<&Operand<'tcx>>,
 501     fn_ty: Ty<'tcx>,
 502     args: Vec<CValue<'tcx>>,
 503     ret_place: Option<CPlace<'tcx>>,
 504 ) {
 505     let sig = ty_fn_sig(fx.tcx, fn_ty);
 506
 507     let ret_layout = fx.layout_of(sig.output());
 508
 509     let output_pass_mode = get_pass_mode(fx.tcx, sig.abi, sig.output(), true);
 510     let return_ptr = match output_pass_mode {
 511         PassMode::NoPass => None,
 512         PassMode::ByRef => match ret_place {
 513             Some(ret_place) => Some(ret_place.expect_addr()),
 514             None => Some(fx.bcx.ins().iconst(fx.module.pointer_type(), 0)),
 515         },
 516         PassMode::ByVal(_) => None,
 517     };
 518
 519     let instance = match fn_ty.sty {
 520         ty::FnDef(def_id, substs) => {
 521             Some(Instance::resolve(fx.tcx, ParamEnv::reveal_all(), def_id, substs).unwrap())
 522         }
 523         _ => None,
 524     };
 525
 526     let func_ref: Option<Value>; // Indirect call target
 527
 528     let first_arg = {
 529         if let Some(Instance {
 530             def: InstanceDef::Virtual(_, idx),
 531             ..
 532         }) = instance
 533         {
 534             let (ptr, method) = crate::vtable::get_ptr_and_method_ref(fx, args[0], idx);
 535             func_ref = Some(method);
 536             Some(ptr)
 537         } else {
 538             func_ref = if instance.is_none() {
 539                 let func = trans_operand(fx, func.expect("indirect call without func Operand"));
 540                 Some(func.load_value(fx))
 541             } else {
 542                 None
 543             };
 544
 545             args.get(0).map(|arg| adjust_arg_for_abi(fx, sig, *arg))
 546         }.into_iter()
 547     };
 548
 549     let call_args: Vec<Value> = return_ptr
 550         .into_iter()
 551         .chain(first_arg)
 552         .chain(
 553             args.into_iter()
 554                 .skip(1)
 555                 .map(|arg| adjust_arg_for_abi(fx, sig, arg)),
 556         ).collect::<Vec<_>>();
 557
 558     let sig = fx.bcx.import_signature(cton_sig_from_fn_ty(fx.tcx, fn_ty));
 559     let call_inst = if let Some(func_ref) = func_ref {
 560         fx.bcx.ins().call_indirect(sig, func_ref, &call_args)
 561     } else {
 562         let func_ref = fx.get_function_ref(instance.expect("non-indirect call on non-FnDef type"));
 563         fx.bcx.ins().call(func_ref, &call_args)
 564     };
 565
 566     match output_pass_mode {
 567         PassMode::NoPass => {}
 568         PassMode::ByVal(_) => {
 569             if let Some(ret_place) = ret_place {
 570                 let results = fx.bcx.inst_results(call_inst);
 571                 ret_place.write_cvalue(fx, CValue::ByVal(results[0], ret_layout));
 572             }
 573         }
 574         PassMode::ByRef => {}
 575     }
 576 }
 577
 578 pub fn codegen_return(fx: &mut FunctionCx<impl Backend>) {
 579     match get_pass_mode(fx.tcx, fx.self_sig().abi, fx.return_type(), true) {
 580         PassMode::NoPass | PassMode::ByRef => {
 581             fx.bcx.ins().return_(&[]);
 582         }
 583         PassMode::ByVal(_) => {
 584             let place = fx.get_local_place(RETURN_PLACE);
 585             let ret_val = place.to_cvalue(fx).load_value(fx);
 586             fx.bcx.ins().return_(&[ret_val]);
 587         }
 588     }
 589 }
 590
 591 fn codegen_intrinsic_call<'a, 'tcx: 'a>(
 592     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 593     fn_ty: Ty<'tcx>,
 594     args: &[CValue<'tcx>],
 595     destination: Option<(CPlace<'tcx>, BasicBlock)>,
 596 ) -> bool {
 597     if let ty::FnDef(def_id, substs) = fn_ty.sty {
 598         let sig = ty_fn_sig(fx.tcx, fn_ty);
 599
 600         if sig.abi == Abi::RustIntrinsic {
 601             let intrinsic = fx.tcx.item_name(def_id).as_str();
 602             let intrinsic = &intrinsic[..];
 603
 604             let ret = match destination {
 605                 Some((place, _)) => place,
 606                 None => {
 607                     // Insert non returning intrinsics here
 608                     match intrinsic {
 609                         "abort" => {
 610                             fx.bcx.ins().trap(TrapCode::User(!0 - 1));
 611                         }
 612                         "unreachable" => {
 613                             fx.bcx.ins().trap(TrapCode::User(!0 - 1));
 614                         }
 615                         _ => unimplemented!("unsupported instrinsic {}", intrinsic),
 616                     }
 617                     return true;
 618                 }
 619             };
 620
 621             let nil_ty = fx.tcx.mk_unit();
 622             let u64_layout = fx.layout_of(fx.tcx.types.u64);
 623             let usize_layout = fx.layout_of(fx.tcx.types.usize);
 624
 625             match intrinsic {
 626                 "assume" => {
 627                     assert_eq!(args.len(), 1);
 628                 }
 629                 "arith_offset" => {
 630                     assert_eq!(args.len(), 2);
 631                     let base = args[0].load_value(fx);
 632                     let offset = args[1].load_value(fx);
 633                     let res = fx.bcx.ins().iadd(base, offset);
 634                     let res = CValue::ByVal(res, ret.layout());
 635                     ret.write_cvalue(fx, res);
 636                 }
 637                 "likely" | "unlikely" => {
 638                     assert_eq!(args.len(), 1);
 639                     ret.write_cvalue(fx, args[0]);
 640                 }
 641                 "copy" | "copy_nonoverlapping" => {
 642                     let elem_ty = substs.type_at(0);
 643                     let elem_size: u64 = fx.layout_of(elem_ty).size.bytes();
 644                     let elem_size = fx
 645                         .bcx
 646                         .ins()
 647                         .iconst(fx.module.pointer_type(), elem_size as i64);
 648                     assert_eq!(args.len(), 3);
 649                     let src = args[0].load_value(fx);
 650                     let dst = args[1].load_value(fx);
 651                     let count = args[2].load_value(fx);
 652                     let byte_amount = fx.bcx.ins().imul(count, elem_size);
 653
 654                     if intrinsic.ends_with("_nonoverlapping") {
 655                         fx.bcx.call_memcpy(fx.isa, dst, src, byte_amount);
 656                     } else {
 657                         fx.bcx.call_memmove(fx.isa, dst, src, byte_amount);
 658                     }
 659                 }
 660                 "discriminant_value" => {
 661                     assert_eq!(args.len(), 1);
 662                     let discr = crate::base::trans_get_discriminant(fx, args[0], ret.layout());
 663                     ret.write_cvalue(fx, discr);
 664                 }
 665                 "size_of" => {
 666                     assert_eq!(args.len(), 0);
 667                     let size_of = fx.layout_of(substs.type_at(0)).size.bytes();
 668                     let size_of = CValue::const_val(fx, usize_layout.ty, size_of as i64);
 669                     ret.write_cvalue(fx, size_of);
 670                 }
 671                 "size_of_val" => {
 672                     assert_eq!(args.len(), 1);
 673                     let layout = fx.layout_of(substs.type_at(0));
 674                     let size = match &layout.ty.sty {
 675                         _ if !layout.is_unsized() => fx
 676                             .bcx
 677                             .ins()
 678                             .iconst(fx.module.pointer_type(), layout.size.bytes() as i64),
 679                         ty::Slice(elem) => {
 680                             let len = args[0].load_value_pair(fx).1;
 681                             let elem_size = fx.layout_of(elem).size.bytes();
 682                             fx.bcx.ins().imul_imm(len, elem_size as i64)
 683                         }
 684                         ty::Dynamic(..) => crate::vtable::size_of_obj(fx, args[0]),
 685                         ty => bug!("size_of_val for unknown unsized type {:?}", ty),
 686                     };
 687                     ret.write_cvalue(fx, CValue::ByVal(size, usize_layout));
 688                 }
 689                 "min_align_of" => {
 690                     assert_eq!(args.len(), 0);
 691                     let min_align = fx.layout_of(substs.type_at(0)).align.abi();
 692                     let min_align = CValue::const_val(fx, usize_layout.ty, min_align as i64);
 693                     ret.write_cvalue(fx, min_align);
 694                 }
 695                 "min_align_of_val" => {
 696                     assert_eq!(args.len(), 1);
 697                     let layout = fx.layout_of(substs.type_at(0));
 698                     let align = match &layout.ty.sty {
 699                         _ if !layout.is_unsized() => fx
 700                             .bcx
 701                             .ins()
 702                             .iconst(fx.module.pointer_type(), layout.align.abi() as i64),
 703                         ty::Slice(elem) => {
 704                             let align = fx.layout_of(elem).align.abi() as i64;
 705                             fx.bcx.ins().iconst(fx.module.pointer_type(), align)
 706                         }
 707                         ty::Dynamic(..) => crate::vtable::min_align_of_obj(fx, args[0]),
 708                         ty => unimplemented!("min_align_of_val for {:?}", ty),
 709                     };
 710                     ret.write_cvalue(fx, CValue::ByVal(align, usize_layout));
 711                 }
 712                 "type_id" => {
 713                     assert_eq!(args.len(), 0);
 714                     let type_id = fx.tcx.type_id_hash(substs.type_at(0));
 715                     let type_id = CValue::const_val(fx, u64_layout.ty, type_id as i64);
 716                     ret.write_cvalue(fx, type_id);
 717                 }
 718                 _ if intrinsic.starts_with("unchecked_") => {
 719                     assert_eq!(args.len(), 2);
 720                     let bin_op = match intrinsic {
 721                         "unchecked_div" => BinOp::Div,
 722                         "unchecked_rem" => BinOp::Rem,
 723                         "unchecked_shl" => BinOp::Shl,
 724                         "unchecked_shr" => BinOp::Shr,
 725                         _ => unimplemented!("intrinsic {}", intrinsic),
 726                     };
 727                     let res = match ret.layout().ty.sty {
 728                         ty::Uint(_) => crate::base::trans_int_binop(
 729                             fx,
 730                             bin_op,
 731                             args[0],
 732                             args[1],
 733                             ret.layout().ty,
 734                             false,
 735                         ),
 736                         ty::Int(_) => crate::base::trans_int_binop(
 737                             fx,
 738                             bin_op,
 739                             args[0],
 740                             args[1],
 741                             ret.layout().ty,
 742                             true,
 743                         ),
 744                         _ => panic!(),
 745                     };
 746                     ret.write_cvalue(fx, res);
 747                 }
 748                 _ if intrinsic.ends_with("_with_overflow") => {
 749                     assert_eq!(args.len(), 2);
 750                     assert_eq!(args[0].layout().ty, args[1].layout().ty);
 751                     let bin_op = match intrinsic {
 752                         "add_with_overflow" => BinOp::Add,
 753                         "sub_with_overflow" => BinOp::Sub,
 754                         "mul_with_overflow" => BinOp::Mul,
 755                         _ => unimplemented!("intrinsic {}", intrinsic),
 756                     };
 757                     let res = match args[0].layout().ty.sty {
 758                         ty::Uint(_) => crate::base::trans_checked_int_binop(
 759                             fx,
 760                             bin_op,
 761                             args[0],
 762                             args[1],
 763                             ret.layout().ty,
 764                             false,
 765                         ),
 766                         ty::Int(_) => crate::base::trans_checked_int_binop(
 767                             fx,
 768                             bin_op,
 769                             args[0],
 770                             args[1],
 771                             ret.layout().ty,
 772                             true,
 773                         ),
 774                         _ => panic!(),
 775                     };
 776                     ret.write_cvalue(fx, res);
 777                 }
 778                 _ if intrinsic.starts_with("overflowing_") => {
 779                     assert_eq!(args.len(), 2);
 780                     assert_eq!(args[0].layout().ty, args[1].layout().ty);
 781                     let bin_op = match intrinsic {
 782                         "overflowing_add" => BinOp::Add,
 783                         "overflowing_sub" => BinOp::Sub,
 784                         "overflowing_mul" => BinOp::Mul,
 785                         _ => unimplemented!("intrinsic {}", intrinsic),
 786                     };
 787                     let res = match args[0].layout().ty.sty {
 788                         ty::Uint(_) => crate::base::trans_int_binop(
 789                             fx,
 790                             bin_op,
 791                             args[0],
 792                             args[1],
 793                             ret.layout().ty,
 794                             false,
 795                         ),
 796                         ty::Int(_) => crate::base::trans_int_binop(
 797                             fx,
 798                             bin_op,
 799                             args[0],
 800                             args[1],
 801                             ret.layout().ty,
 802                             true,
 803                         ),
 804                         _ => panic!(),
 805                     };
 806                     ret.write_cvalue(fx, res);
 807                 }
 808                 "offset" => {
 809                     assert_eq!(args.len(), 2);
 810                     let base = args[0].load_value(fx);
 811                     let offset = args[1].load_value(fx);
 812                     let res = fx.bcx.ins().iadd(base, offset);
 813                     ret.write_cvalue(fx, CValue::ByVal(res, args[0].layout()));
 814                 }
 815                 "transmute" => {
 816                     assert_eq!(args.len(), 1);
 817                     let src_ty = substs.type_at(0);
 818                     let dst_ty = substs.type_at(1);
 819                     assert_eq!(args[0].layout().ty, src_ty);
 820                     let addr = args[0].force_stack(fx);
 821                     let dst_layout = fx.layout_of(dst_ty);
 822                     ret.write_cvalue(fx, CValue::ByRef(addr, dst_layout))
 823                 }
 824                 "uninit" => {
 825                     assert_eq!(args.len(), 0);
 826                     let ty = substs.type_at(0);
 827                     let layout = fx.layout_of(ty);
 828                     let stack_slot = fx.bcx.create_stack_slot(StackSlotData {
 829                         kind: StackSlotKind::ExplicitSlot,
 830                         size: layout.size.bytes() as u32,
 831                         offset: None,
 832                     });
 833
 834                     let uninit_place = CPlace::from_stack_slot(fx, stack_slot, ty);
 835                     let uninit_val = uninit_place.to_cvalue(fx);
 836                     ret.write_cvalue(fx, uninit_val);
 837                 }
 838                 "ctlz" | "ctlz_nonzero" => {
 839                     assert_eq!(args.len(), 1);
 840                     let arg = args[0].load_value(fx);
 841                     let res = CValue::ByVal(fx.bcx.ins().clz(arg), args[0].layout());
 842                     ret.write_cvalue(fx, res);
 843                 }
 844                 "cttz" | "cttz_nonzero" => {
 845                     assert_eq!(args.len(), 1);
 846                     let arg = args[0].load_value(fx);
 847                     let res = CValue::ByVal(fx.bcx.ins().clz(arg), args[0].layout());
 848                     ret.write_cvalue(fx, res);
 849                 }
 850                 "ctpop" => {
 851                     assert_eq!(args.len(), 1);
 852                     let arg = args[0].load_value(fx);
 853                     let res = CValue::ByVal(fx.bcx.ins().popcnt(arg), args[0].layout());
 854                     ret.write_cvalue(fx, res);
 855                 }
 856                 "needs_drop" => {
 857                     assert_eq!(args.len(), 0);
 858                     let ty = substs.type_at(0);
 859                     let needs_drop = if ty.needs_drop(fx.tcx, ParamEnv::reveal_all()) {
 860                         1
 861                     } else {
 862                         0
 863                     };
 864                     let needs_drop = CValue::const_val(fx, fx.tcx.types.bool, needs_drop);
 865                     ret.write_cvalue(fx, needs_drop);
 866                 }
 867                 _ if intrinsic.starts_with("atomic_fence") => {}
 868                 _ if intrinsic.starts_with("atomic_load") => {
 869                     assert_eq!(args.len(), 1);
 870                     let inner_layout =
 871                         fx.layout_of(args[0].layout().ty.builtin_deref(true).unwrap().ty);
 872                     let val = CValue::ByRef(args[0].load_value(fx), inner_layout);
 873                     ret.write_cvalue(fx, val);
 874                 }
 875                 _ if intrinsic.starts_with("atomic_store") => {
 876                     assert_eq!(args.len(), 2);
 877                     let dest = CPlace::Addr(args[0].load_value(fx), None, args[1].layout());
 878                     dest.write_cvalue(fx, args[1]);
 879                 }
 880                 _ if intrinsic.starts_with("atomic_xadd") => {
 881                     assert_eq!(args.len(), 2);
 882                     let clif_ty = fx.cton_type(substs.type_at(0)).unwrap();
 883                     let ptr = args[0].load_value(fx);
 884                     let amount = args[1].load_value(fx);
 885                     let old = fx.bcx.ins().load(clif_ty, MemFlags::new(), ptr, 0);
 886                     let new = fx.bcx.ins().iadd(old, amount);
 887                     fx.bcx.ins().store(MemFlags::new(), ptr, new, 0);
 888                     ret.write_cvalue(fx, CValue::ByVal(old, fx.layout_of(substs.type_at(0))));
 889                 }
 890                 _ if intrinsic.starts_with("atomic_xsub") => {
 891                     assert_eq!(args.len(), 2);
 892                     let clif_ty = fx.cton_type(substs.type_at(0)).unwrap();
 893                     let ptr = args[0].load_value(fx);
 894                     let amount = args[1].load_value(fx);
 895                     let old = fx.bcx.ins().load(clif_ty, MemFlags::new(), ptr, 0);
 896                     let new = fx.bcx.ins().isub(old, amount);
 897                     fx.bcx.ins().store(MemFlags::new(), ptr, new, 0);
 898                     ret.write_cvalue(fx, CValue::ByVal(old, fx.layout_of(substs.type_at(0))));
 899                 }
 900                 _ => unimpl!("unsupported intrinsic {}", intrinsic),
 901             }
 902
 903             if let Some((_, dest)) = destination {
 904                 let ret_ebb = fx.get_ebb(dest);
 905                 fx.bcx.ins().jump(ret_ebb, &[]);
 906             } else {
 907                 fx.bcx.ins().trap(TrapCode::User(!0));
 908             }
 909             return true;
 910         }
 911     }
 912
 913     false
 914 }