src/abi.rs

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