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) -> Type {
  17         match self {
  18             PassMode::NoPass => unimplemented!("pass mode nopass"),
  19             PassMode::ByVal(cton_type) => cton_type,
  20             PassMode::ByRef => types::I64,
  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     if ty.sty == tcx.mk_nil().sty {
  32         if is_return {
  33             //if false {
  34             PassMode::NoPass
  35         } else {
  36             PassMode::ByRef
  37         }
  38     } else if let Some(ret_ty) = crate::common::cton_type_from_ty(tcx, ty) {
  39         PassMode::ByVal(ret_ty)
  40     } else {
  41         if abi == Abi::C {
  42             unimplemented!("Non scalars are not yet supported for \"C\" abi");
  43         }
  44         PassMode::ByRef
  45     }
  46 }
  47
  48 pub fn cton_sig_from_fn_ty<'a, 'tcx: 'a>(
  49     tcx: TyCtxt<'a, 'tcx, 'tcx>,
  50     fn_ty: Ty<'tcx>,
  51 ) -> Signature {
  52     let sig = ty_fn_sig(tcx, fn_ty);
  53     assert!(!sig.variadic, "Variadic function are not yet supported");
  54     let (call_conv, inputs, output): (CallConv, Vec<Ty>, Ty) = match sig.abi {
  55         Abi::Rust => (CallConv::Fast, sig.inputs().to_vec(), sig.output()),
  56         Abi::C => (CallConv::SystemV, sig.inputs().to_vec(), sig.output()),
  57         Abi::RustCall => {
  58             println!(
  59                 "rust-call sig: {:?} inputs: {:?} output: {:?}",
  60                 sig,
  61                 sig.inputs(),
  62                 sig.output()
  63             );
  64             assert_eq!(sig.inputs().len(), 2);
  65             let extra_args = match sig.inputs().last().unwrap().sty {
  66                 ty::TyTuple(ref tupled_arguments) => tupled_arguments,
  67                 _ => bug!("argument to function with \"rust-call\" ABI is not a tuple"),
  68             };
  69             let mut inputs: Vec<Ty> = vec![sig.inputs()[0]];
  70             inputs.extend(extra_args.into_iter());
  71             (CallConv::Fast, inputs, sig.output())
  72         }
  73         Abi::System => bug!("system abi should be selected elsewhere"),
  74         Abi::RustIntrinsic => (CallConv::SystemV, sig.inputs().to_vec(), sig.output()),
  75         _ => unimplemented!("unsupported abi {:?}", sig.abi),
  76     };
  77
  78     let inputs = inputs
  79         .into_iter()
  80         .filter_map(|ty| match get_pass_mode(tcx, sig.abi, ty, false) {
  81             PassMode::ByVal(cton_ty) => Some(cton_ty),
  82             PassMode::NoPass => unimplemented!("pass mode nopass"),
  83             PassMode::ByRef => Some(types::I64),
  84         });
  85
  86     let (params, returns) = match get_pass_mode(tcx, sig.abi, output, true) {
  87         PassMode::NoPass => (inputs.map(AbiParam::new).collect(), vec![]),
  88         PassMode::ByVal(ret_ty) => (
  89             inputs.map(AbiParam::new).collect(),
  90             vec![AbiParam::new(ret_ty)],
  91         ),
  92         PassMode::ByRef => {
  93             (
  94                 Some(types::I64).into_iter() // First param is place to put return val
  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         argument_bytes: None,
 108     }
 109 }
 110
 111 fn ty_fn_sig<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, ty: Ty<'tcx>) -> ty::FnSig<'tcx> {
 112     let sig = match ty.sty {
 113         ty::TyFnDef(..) |
 114         // Shims currently have type TyFnPtr. Not sure this should remain.
 115         ty::TyFnPtr(_) => ty.fn_sig(tcx),
 116         ty::TyClosure(def_id, substs) => {
 117             let sig = substs.closure_sig(def_id, tcx);
 118
 119             let env_ty = tcx.closure_env_ty(def_id, substs).unwrap();
 120             sig.map_bound(|sig| tcx.mk_fn_sig(
 121                 iter::once(*env_ty.skip_binder()).chain(sig.inputs().iter().cloned()),
 122                 sig.output(),
 123                 sig.variadic,
 124                 sig.unsafety,
 125                 sig.abi
 126             ))
 127         }
 128         ty::TyGenerator(def_id, substs, _) => {
 129             let sig = substs.poly_sig(def_id, tcx);
 130
 131             let env_region = ty::ReLateBound(ty::INNERMOST, ty::BrEnv);
 132             let env_ty = tcx.mk_mut_ref(tcx.mk_region(env_region), ty);
 133
 134             sig.map_bound(|sig| {
 135                 let state_did = tcx.lang_items().gen_state().unwrap();
 136                 let state_adt_ref = tcx.adt_def(state_did);
 137                 let state_substs = tcx.intern_substs(&[
 138                     sig.yield_ty.into(),
 139                     sig.return_ty.into(),
 140                 ]);
 141                 let ret_ty = tcx.mk_adt(state_adt_ref, state_substs);
 142
 143                 tcx.mk_fn_sig(iter::once(env_ty),
 144                     ret_ty,
 145                     false,
 146                     hir::Unsafety::Normal,
 147                     Abi::Rust
 148                 )
 149             })
 150         }
 151         _ => bug!("unexpected type {:?} to ty_fn_sig", ty)
 152     };
 153     tcx.normalize_erasing_late_bound_regions(ParamEnv::reveal_all(), &sig)
 154 }
 155
 156 pub fn get_function_name_and_sig<'a, 'tcx>(
 157     tcx: TyCtxt<'a, 'tcx, 'tcx>,
 158     inst: Instance<'tcx>,
 159 ) -> (String, Signature) {
 160     assert!(!inst.substs.needs_infer() && !inst.substs.has_param_types());
 161     let fn_ty = inst.ty(tcx);
 162     let sig = cton_sig_from_fn_ty(tcx, fn_ty);
 163     let def_path_based_names =
 164         ::rustc_mir::monomorphize::item::DefPathBasedNames::new(tcx, false, false);
 165     let mut name = String::new();
 166     def_path_based_names.push_instance_as_string(inst, &mut name);
 167     (name, sig)
 168 }
 169
 170 impl<'a, 'tcx: 'a> CodegenCx<'a, 'tcx, CurrentBackend> {
 171     pub fn predefine_function(&mut self, inst: Instance<'tcx>) -> (FuncId, Function) {
 172         let (name, sig) = crate::abi::get_function_name_and_sig(self.tcx, inst);
 173         let func_id = self
 174             .module
 175             .declare_function(&name, Linkage::Export, &sig)
 176             .unwrap();
 177         let func =
 178             Function::with_name_signature(ExternalName::user(0, func_id.index() as u32), sig);
 179         (func_id, func)
 180     }
 181 }
 182
 183 impl<'a, 'tcx: 'a> FunctionCx<'a, 'tcx> {
 184     /// Instance must be monomorphized
 185     pub fn get_function_ref(&mut self, inst: Instance<'tcx>) -> FuncRef {
 186         let (name, sig) = get_function_name_and_sig(self.tcx, inst);
 187         let func_id = self
 188             .module
 189             .declare_function(&name, Linkage::Import, &sig)
 190             .unwrap();
 191         self.module
 192             .declare_func_in_func(func_id, &mut self.bcx.func)
 193     }
 194
 195     fn lib_call(
 196         &mut self,
 197         name: &str,
 198         input_tys: Vec<types::Type>,
 199         output_ty: Option<types::Type>,
 200         args: &[Value],
 201     ) -> Option<Value> {
 202         let sig = Signature {
 203             params: input_tys.iter().cloned().map(AbiParam::new).collect(),
 204             returns: vec![AbiParam::new(output_ty.unwrap_or(types::VOID))],
 205             call_conv: CallConv::SystemV,
 206             argument_bytes: None,
 207         };
 208         let func_id = self
 209             .module
 210             .declare_function(&name, Linkage::Import, &sig)
 211             .unwrap();
 212         let func_ref = self
 213             .module
 214             .declare_func_in_func(func_id, &mut self.bcx.func);
 215         let call_inst = self.bcx.ins().call(func_ref, args);
 216         if output_ty.is_none() {
 217             return None;
 218         }
 219         let results = self.bcx.inst_results(call_inst);
 220         assert_eq!(results.len(), 1);
 221         Some(results[0])
 222     }
 223
 224     pub fn easy_call(
 225         &mut self,
 226         name: &str,
 227         args: &[CValue<'tcx>],
 228         return_ty: Ty<'tcx>,
 229     ) -> CValue<'tcx> {
 230         let (input_tys, args): (Vec<_>, Vec<_>) = args
 231             .into_iter()
 232             .map(|arg| {
 233                 (
 234                     self.cton_type(arg.layout().ty).unwrap(),
 235                     arg.load_value(self),
 236                 )
 237             }).unzip();
 238         let return_layout = self.layout_of(return_ty);
 239         let return_ty = if let TypeVariants::TyTuple(tup) = return_ty.sty {
 240             if !tup.is_empty() {
 241                 bug!("easy_call( (...) -> <non empty tuple> ) is not allowed");
 242             }
 243             None
 244         } else {
 245             Some(self.cton_type(return_ty).unwrap())
 246         };
 247         if let Some(val) = self.lib_call(name, input_tys, return_ty, &args) {
 248             CValue::ByVal(val, return_layout)
 249         } else {
 250             CValue::ByRef(self.bcx.ins().iconst(types::I64, 0), return_layout)
 251         }
 252     }
 253
 254     fn self_sig(&self) -> FnSig<'tcx> {
 255         ty_fn_sig(self.tcx, self.instance.ty(self.tcx))
 256     }
 257
 258     fn return_type(&self) -> Ty<'tcx> {
 259         self.self_sig().output()
 260     }
 261 }
 262
 263 pub fn codegen_fn_prelude<'a, 'tcx: 'a>(fx: &mut FunctionCx<'a, 'tcx>, start_ebb: Ebb) {
 264     let ssa_analyzed = crate::analyze::analyze(fx);
 265     fx.tcx.sess.warn(&format!("ssa {:?}", ssa_analyzed));
 266
 267     match fx.self_sig().abi {
 268         Abi::Rust | Abi::RustCall => {}
 269         _ => unimplemented!("declared function with non \"rust\" or \"rust-call\" abi"),
 270     }
 271
 272     let ret_layout = fx.layout_of(fx.return_type());
 273     let output_pass_mode = get_pass_mode(fx.tcx, fx.self_sig().abi, fx.return_type(), true);
 274     let ret_param = match output_pass_mode {
 275         PassMode::NoPass => None,
 276         PassMode::ByVal(ret_ty) => None,
 277         PassMode::ByRef => Some(fx.bcx.append_ebb_param(start_ebb, types::I64)),
 278     };
 279
 280     enum ArgKind {
 281         Normal(Value),
 282         Spread(Vec<Value>),
 283     }
 284
 285     let func_params = fx.mir.args_iter().map(|local| {
 286         let arg_ty = fx.monomorphize(&fx.mir.local_decls[local].ty);
 287
 288         // Adapted from https://github.com/rust-lang/rust/blob/145155dc96757002c7b2e9de8489416e2fdbbd57/src/librustc_codegen_llvm/mir/mod.rs#L442-L482
 289         if Some(local) == fx.mir.spread_arg {
 290             // This argument (e.g. the last argument in the "rust-call" ABI)
 291             // is a tuple that was spread at the ABI level and now we have
 292             // to reconstruct it into a tuple local variable, from multiple
 293             // individual function arguments.
 294
 295             let tupled_arg_tys = match arg_ty.sty {
 296                 ty::TyTuple(ref tys) => tys,
 297                 _ => bug!("spread argument isn't a tuple?! but {:?}", arg_ty),
 298             };
 299
 300             let mut ebb_params = Vec::new();
 301             for arg_ty in tupled_arg_tys.iter() {
 302                 let cton_type = get_pass_mode(fx.tcx, fx.self_sig().abi, arg_ty, false).get_param_ty(fx);
 303                 ebb_params.push(fx.bcx.append_ebb_param(start_ebb, cton_type));
 304             }
 305
 306             (local, ArgKind::Spread(ebb_params), arg_ty)
 307         } else {
 308             let cton_type = get_pass_mode(fx.tcx, fx.self_sig().abi, arg_ty, false).get_param_ty(fx);
 309             (local, ArgKind::Normal(fx.bcx.append_ebb_param(start_ebb, cton_type)), arg_ty)
 310         }
 311     }).collect::<Vec<(Local, ArgKind, Ty)>>();
 312
 313     match output_pass_mode {
 314         PassMode::NoPass => {
 315             let null = fx.bcx.ins().iconst(types::I64, 0);
 316             //unimplemented!("pass mode nopass");
 317             fx.local_map.insert(
 318                 RETURN_PLACE,
 319                 CPlace::Addr(null, fx.layout_of(fx.return_type())),
 320             );
 321         }
 322         PassMode::ByVal(ret_ty) => {
 323             let var = Variable(RETURN_PLACE);
 324             fx.bcx.declare_var(var, ret_ty);
 325             fx.local_map
 326                 .insert(RETURN_PLACE, CPlace::Var(var, ret_layout));
 327         }
 328         PassMode::ByRef => {
 329             fx.local_map
 330                 .insert(RETURN_PLACE, CPlace::Addr(ret_param.unwrap(), ret_layout));
 331         }
 332     }
 333
 334     for (local, arg_kind, ty) in func_params {
 335         let layout = fx.layout_of(ty);
 336
 337         if let ArgKind::Normal(ebb_param) = arg_kind {
 338             if !ssa_analyzed
 339                 .get(&local)
 340                 .unwrap()
 341                 .contains(crate::analyze::Flags::NOT_SSA)
 342             {
 343                 let var = Variable(local);
 344                 fx.bcx.declare_var(var, fx.cton_type(ty).unwrap());
 345                 match get_pass_mode(fx.tcx, fx.self_sig().abi, ty, false) {
 346                     PassMode::NoPass => unimplemented!("pass mode nopass"),
 347                     PassMode::ByVal(_) => fx.bcx.def_var(var, ebb_param),
 348                     PassMode::ByRef => {
 349                         let val = CValue::ByRef(ebb_param, fx.layout_of(ty)).load_value(fx);
 350                         fx.bcx.def_var(var, val);
 351                     }
 352                 }
 353                 fx.local_map.insert(local, CPlace::Var(var, layout));
 354                 continue;
 355             }
 356         }
 357
 358         let stack_slot = fx.bcx.create_stack_slot(StackSlotData {
 359             kind: StackSlotKind::ExplicitSlot,
 360             size: layout.size.bytes() as u32,
 361             offset: None,
 362         });
 363
 364         let place = CPlace::from_stack_slot(fx, stack_slot, ty);
 365
 366         match arg_kind {
 367             ArgKind::Normal(ebb_param) => match get_pass_mode(fx.tcx, fx.self_sig().abi, ty, false)
 368             {
 369                 PassMode::NoPass => unimplemented!("pass mode nopass"),
 370                 PassMode::ByVal(_) => {
 371                     place.write_cvalue(fx, CValue::ByVal(ebb_param, place.layout()))
 372                 }
 373                 PassMode::ByRef => place.write_cvalue(fx, CValue::ByRef(ebb_param, place.layout())),
 374             },
 375             ArgKind::Spread(ebb_params) => {
 376                 for (i, ebb_param) in ebb_params.into_iter().enumerate() {
 377                     let sub_place = place.place_field(fx, mir::Field::new(i));
 378                     match get_pass_mode(fx.tcx, fx.self_sig().abi, sub_place.layout().ty, false) {
 379                         PassMode::NoPass => unimplemented!("pass mode nopass"),
 380                         PassMode::ByVal(_) => {
 381                             sub_place.write_cvalue(fx, CValue::ByVal(ebb_param, sub_place.layout()))
 382                         }
 383                         PassMode::ByRef => {
 384                             sub_place.write_cvalue(fx, CValue::ByRef(ebb_param, sub_place.layout()))
 385                         }
 386                     }
 387                 }
 388             }
 389         }
 390         fx.local_map.insert(local, place);
 391     }
 392
 393     for local in fx.mir.vars_and_temps_iter() {
 394         let ty = fx.mir.local_decls[local].ty;
 395         let layout = fx.layout_of(ty);
 396
 397         let place = if ssa_analyzed
 398             .get(&local)
 399             .unwrap()
 400             .contains(crate::analyze::Flags::NOT_SSA)
 401         {
 402             let stack_slot = fx.bcx.create_stack_slot(StackSlotData {
 403                 kind: StackSlotKind::ExplicitSlot,
 404                 size: layout.size.bytes() as u32,
 405                 offset: None,
 406             });
 407             CPlace::from_stack_slot(fx, stack_slot, ty)
 408         } else {
 409             let var = Variable(local);
 410             fx.bcx.declare_var(var, fx.cton_type(ty).unwrap());
 411             CPlace::Var(var, layout)
 412         };
 413
 414         fx.local_map.insert(local, place);
 415     }
 416 }
 417
 418 pub fn codegen_call<'a, 'tcx: 'a>(
 419     fx: &mut FunctionCx<'a, 'tcx>,
 420     func: &Operand<'tcx>,
 421     args: &[Operand<'tcx>],
 422     destination: &Option<(Place<'tcx>, BasicBlock)>,
 423 ) {
 424     let func = trans_operand(fx, func);
 425     let fn_ty = func.layout().ty;
 426     let sig = ty_fn_sig(fx.tcx, fn_ty);
 427
 428     // Unpack arguments tuple for closures
 429     let args = if sig.abi == Abi::RustCall {
 430         assert_eq!(args.len(), 2, "rust-call abi requires two arguments");
 431         let self_arg = trans_operand(fx, &args[0]);
 432         let pack_arg = trans_operand(fx, &args[1]);
 433         let mut args = Vec::new();
 434         args.push(self_arg);
 435         match pack_arg.layout().ty.sty {
 436             ty::TyTuple(ref tupled_arguments) => {
 437                 for (i, _) in tupled_arguments.iter().enumerate() {
 438                     args.push(pack_arg.value_field(fx, mir::Field::new(i)));
 439                 }
 440             }
 441             _ => bug!("argument to function with \"rust-call\" ABI is not a tuple"),
 442         }
 443         println!(
 444             "{:?} {:?}",
 445             pack_arg.layout().ty,
 446             args.iter().map(|a| a.layout().ty).collect::<Vec<_>>()
 447         );
 448         args
 449     } else {
 450         args.into_iter()
 451             .map(|arg| trans_operand(fx, arg))
 452             .collect::<Vec<_>>()
 453     };
 454
 455     let destination = destination
 456         .as_ref()
 457         .map(|(place, bb)| (trans_place(fx, place), *bb));
 458
 459     if codegen_intrinsic_call(fx, fn_ty, sig, &args, destination) {
 460         return;
 461     }
 462
 463     let ret_layout = fx.layout_of(sig.output());
 464
 465     let output_pass_mode = get_pass_mode(fx.tcx, sig.abi, sig.output(), true);
 466     println!("{:?}", output_pass_mode);
 467     let return_ptr = match output_pass_mode {
 468         PassMode::NoPass => None,
 469         PassMode::ByRef => match destination {
 470             Some((place, _)) => Some(place.expect_addr()),
 471             None => Some(fx.bcx.ins().iconst(types::I64, 0)),
 472         },
 473         PassMode::ByVal(_) => None,
 474     };
 475
 476     let call_args: Vec<Value> = return_ptr
 477         .into_iter()
 478         .chain(args.into_iter().map(|arg| {
 479             match get_pass_mode(fx.tcx, sig.abi, arg.layout().ty, false) {
 480                 PassMode::NoPass => unimplemented!("pass mode nopass"),
 481                 PassMode::ByVal(_) => arg.load_value(fx),
 482                 PassMode::ByRef => arg.force_stack(fx),
 483             }
 484         })).collect::<Vec<_>>();
 485
 486     let inst = match func {
 487         CValue::Func(func, _) => fx.bcx.ins().call(func, &call_args),
 488         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     };
 494
 495     match output_pass_mode {
 496         PassMode::NoPass => {}
 497         PassMode::ByVal(_) => {
 498             if let Some((ret_place, _)) = destination {
 499                 let results = fx.bcx.inst_results(inst);
 500                 ret_place.write_cvalue(fx, CValue::ByVal(results[0], ret_layout));
 501             }
 502         }
 503         PassMode::ByRef => {}
 504     }
 505     if let Some((_, dest)) = destination {
 506         let ret_ebb = fx.get_ebb(dest);
 507         fx.bcx.ins().jump(ret_ebb, &[]);
 508     } else {
 509         fx.bcx.ins().trap(TrapCode::User(!0));
 510     }
 511 }
 512
 513 pub fn codegen_return(fx: &mut FunctionCx) {
 514     match get_pass_mode(fx.tcx, fx.self_sig().abi, fx.return_type(), true) {
 515         PassMode::NoPass | PassMode::ByRef => {
 516             fx.bcx.ins().return_(&[]);
 517         }
 518         PassMode::ByVal(_) => {
 519             let place = fx.get_local_place(RETURN_PLACE);
 520             let ret_val = place.to_cvalue(fx).load_value(fx);
 521             fx.bcx.ins().return_(&[ret_val]);
 522         }
 523     }
 524 }
 525
 526 fn codegen_intrinsic_call<'a, 'tcx: 'a>(
 527     fx: &mut FunctionCx<'a, 'tcx>,
 528     fn_ty: Ty<'tcx>,
 529     sig: FnSig<'tcx>,
 530     args: &[CValue<'tcx>],
 531     destination: Option<(CPlace<'tcx>, BasicBlock)>,
 532 ) -> bool {
 533     if let TypeVariants::TyFnDef(def_id, substs) = fn_ty.sty {
 534         if sig.abi == Abi::RustIntrinsic {
 535             let intrinsic = fx.tcx.item_name(def_id).as_str();
 536             let intrinsic = &intrinsic[..];
 537
 538             let ret = match destination {
 539                 Some((place, _)) => place,
 540                 None => {
 541                     println!("codegen_call(fx, _, {:?}, {:?})", args, destination);
 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.bcx.ins().iconst(types::I64, elem_size as i64);
 580                     assert_eq!(args.len(), 3);
 581                     let src = args[0];
 582                     let dst = args[1];
 583                     let count = args[2].load_value(fx);
 584                     let byte_amount = fx.bcx.ins().imul(count, elem_size);
 585                     fx.easy_call(
 586                         "memmove",
 587                         &[dst, src, CValue::ByVal(byte_amount, usize_layout)],
 588                         nil_ty,
 589                     );
 590                 }
 591                 "discriminant_value" => {
 592                     assert_eq!(args.len(), 1);
 593                     let discr = crate::base::trans_get_discriminant(fx, args[0], ret.layout());
 594                     ret.write_cvalue(fx, discr);
 595                 }
 596                 "size_of" => {
 597                     assert_eq!(args.len(), 0);
 598                     let size_of = fx.layout_of(substs.type_at(0)).size.bytes();
 599                     let size_of = CValue::const_val(fx, usize_layout.ty, size_of as i64);
 600                     ret.write_cvalue(fx, size_of);
 601                 }
 602                 "type_id" => {
 603                     assert_eq!(args.len(), 0);
 604                     let type_id = fx.tcx.type_id_hash(substs.type_at(0));
 605                     let type_id = CValue::const_val(fx, u64_layout.ty, type_id as i64);
 606                     ret.write_cvalue(fx, type_id);
 607                 }
 608                 "min_align_of" => {
 609                     assert_eq!(args.len(), 0);
 610                     let min_align = fx.layout_of(substs.type_at(0)).align.abi();
 611                     let min_align = CValue::const_val(fx, usize_layout.ty, min_align as i64);
 612                     ret.write_cvalue(fx, min_align);
 613                 }
 614                 _ if intrinsic.starts_with("unchecked_") => {
 615                     assert_eq!(args.len(), 2);
 616                     let bin_op = match intrinsic {
 617                         "unchecked_div" => BinOp::Div,
 618                         "unchecked_rem" => BinOp::Rem,
 619                         "unchecked_shl" => BinOp::Shl,
 620                         "unchecked_shr" => BinOp::Shr,
 621                         _ => unimplemented!("intrinsic {}", intrinsic),
 622                     };
 623                     let res = match ret.layout().ty.sty {
 624                         TypeVariants::TyUint(_) => crate::base::trans_int_binop(
 625                             fx,
 626                             bin_op,
 627                             args[0],
 628                             args[1],
 629                             ret.layout().ty,
 630                             false,
 631                         ),
 632                         TypeVariants::TyInt(_) => crate::base::trans_int_binop(
 633                             fx,
 634                             bin_op,
 635                             args[0],
 636                             args[1],
 637                             ret.layout().ty,
 638                             true,
 639                         ),
 640                         _ => panic!(),
 641                     };
 642                     ret.write_cvalue(fx, res);
 643                 }
 644                 _ if intrinsic.ends_with("_with_overflow") => {
 645                     assert_eq!(args.len(), 2);
 646                     assert_eq!(args[0].layout().ty, args[1].layout().ty);
 647                     let bin_op = match intrinsic {
 648                         "add_with_overflow" => BinOp::Add,
 649                         "sub_with_overflow" => BinOp::Sub,
 650                         "mul_with_overflow" => BinOp::Mul,
 651                         _ => unimplemented!("intrinsic {}", intrinsic),
 652                     };
 653                     let res = match args[0].layout().ty.sty {
 654                         TypeVariants::TyUint(_) => crate::base::trans_checked_int_binop(
 655                             fx,
 656                             bin_op,
 657                             args[0],
 658                             args[1],
 659                             ret.layout().ty,
 660                             false,
 661                         ),
 662                         TypeVariants::TyInt(_) => crate::base::trans_checked_int_binop(
 663                             fx,
 664                             bin_op,
 665                             args[0],
 666                             args[1],
 667                             ret.layout().ty,
 668                             true,
 669                         ),
 670                         _ => panic!(),
 671                     };
 672                     ret.write_cvalue(fx, res);
 673                 }
 674                 _ if intrinsic.starts_with("overflowing_") => {
 675                     assert_eq!(args.len(), 2);
 676                     assert_eq!(args[0].layout().ty, args[1].layout().ty);
 677                     let bin_op = match intrinsic {
 678                         "overflowing_add" => BinOp::Add,
 679                         "overflowing_sub" => BinOp::Sub,
 680                         "overflowing_mul" => BinOp::Mul,
 681                         _ => unimplemented!("intrinsic {}", intrinsic),
 682                     };
 683                     let res = match args[0].layout().ty.sty {
 684                         TypeVariants::TyUint(_) => crate::base::trans_int_binop(
 685                             fx,
 686                             bin_op,
 687                             args[0],
 688                             args[1],
 689                             ret.layout().ty,
 690                             false,
 691                         ),
 692                         TypeVariants::TyInt(_) => crate::base::trans_int_binop(
 693                             fx,
 694                             bin_op,
 695                             args[0],
 696                             args[1],
 697                             ret.layout().ty,
 698                             true,
 699                         ),
 700                         _ => panic!(),
 701                     };
 702                     ret.write_cvalue(fx, res);
 703                 }
 704                 "offset" => {
 705                     assert_eq!(args.len(), 2);
 706                     let base = args[0].load_value(fx);
 707                     let offset = args[1].load_value(fx);
 708                     let res = fx.bcx.ins().iadd(base, offset);
 709                     ret.write_cvalue(fx, CValue::ByVal(res, args[0].layout()));
 710                 }
 711                 "transmute" => {
 712                     assert_eq!(args.len(), 1);
 713                     let src_ty = substs.type_at(0);
 714                     let dst_ty = substs.type_at(1);
 715                     assert_eq!(args[0].layout().ty, src_ty);
 716                     let addr = args[0].force_stack(fx);
 717                     let dst_layout = fx.layout_of(dst_ty);
 718                     ret.write_cvalue(fx, CValue::ByRef(addr, dst_layout))
 719                 }
 720                 "uninit" => {
 721                     assert_eq!(args.len(), 0);
 722                     let ty = substs.type_at(0);
 723                     let layout = fx.layout_of(ty);
 724                     let stack_slot = fx.bcx.create_stack_slot(StackSlotData {
 725                         kind: StackSlotKind::ExplicitSlot,
 726                         size: layout.size.bytes() as u32,
 727                         offset: None,
 728                     });
 729
 730                     let uninit_place = CPlace::from_stack_slot(fx, stack_slot, ty);
 731                     let uninit_val = uninit_place.to_cvalue(fx);
 732                     ret.write_cvalue(fx, uninit_val);
 733                 }
 734                 "ctlz" | "ctlz_nonzero" => {
 735                     assert_eq!(args.len(), 1);
 736                     let arg = args[0].load_value(fx);
 737                     let res = CValue::ByVal(fx.bcx.ins().clz(arg), args[0].layout());
 738                     ret.write_cvalue(fx, res);
 739                 }
 740                 "cttz" | "cttz_nonzero" => {
 741                     assert_eq!(args.len(), 1);
 742                     let arg = args[0].load_value(fx);
 743                     let res = CValue::ByVal(fx.bcx.ins().clz(arg), args[0].layout());
 744                     ret.write_cvalue(fx, res);
 745                 }
 746                 "ctpop" => {
 747                     assert_eq!(args.len(), 1);
 748                     let arg = args[0].load_value(fx);
 749                     let res = CValue::ByVal(fx.bcx.ins().popcnt(arg), args[0].layout());
 750                     ret.write_cvalue(fx, res);
 751                 }
 752                 _ => unimpl!("unsupported intrinsic {}", intrinsic),
 753             }
 754
 755             if let Some((_, dest)) = destination {
 756                 let ret_ebb = fx.get_ebb(dest);
 757                 fx.bcx.ins().jump(ret_ebb, &[]);
 758             } else {
 759                 fx.bcx.ins().trap(TrapCode::User(!0));
 760             }
 761             return true;
 762         }
 763     }
 764
 765     false
 766 }