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