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