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 fn_ty = fx.monomorphize(&func.ty(&fx.mir.local_decls, fx.tcx));
 425     let sig = ty_fn_sig(fx.tcx, fn_ty);
 426
 427     // Unpack arguments tuple for closures
 428     let args = if sig.abi == Abi::RustCall {
 429         assert_eq!(args.len(), 2, "rust-call abi requires two arguments");
 430         let self_arg = trans_operand(fx, &args[0]);
 431         let pack_arg = trans_operand(fx, &args[1]);
 432         let mut args = Vec::new();
 433         args.push(self_arg);
 434         match pack_arg.layout().ty.sty {
 435             ty::TyTuple(ref tupled_arguments) => {
 436                 for (i, _) in tupled_arguments.iter().enumerate() {
 437                     args.push(pack_arg.value_field(fx, mir::Field::new(i)));
 438                 }
 439             }
 440             _ => bug!("argument to function with \"rust-call\" ABI is not a tuple"),
 441         }
 442         println!(
 443             "{:?} {:?}",
 444             pack_arg.layout().ty,
 445             args.iter().map(|a| a.layout().ty).collect::<Vec<_>>()
 446         );
 447         args
 448     } else {
 449         args.into_iter()
 450             .map(|arg| trans_operand(fx, arg))
 451             .collect::<Vec<_>>()
 452     };
 453
 454     let destination = destination
 455         .as_ref()
 456         .map(|(place, bb)| (trans_place(fx, place), *bb));
 457
 458     if codegen_intrinsic_call(fx, fn_ty, sig, &args, destination) {
 459         return;
 460     }
 461
 462     let ret_layout = fx.layout_of(sig.output());
 463
 464     let output_pass_mode = get_pass_mode(fx.tcx, sig.abi, sig.output(), true);
 465     println!("{:?}", output_pass_mode);
 466     let return_ptr = match output_pass_mode {
 467         PassMode::NoPass => None,
 468         PassMode::ByRef => match destination {
 469             Some((place, _)) => Some(place.expect_addr()),
 470             None => Some(fx.bcx.ins().iconst(types::I64, 0)),
 471         },
 472         PassMode::ByVal(_) => None,
 473     };
 474
 475     let call_args: Vec<Value> = return_ptr
 476         .into_iter()
 477         .chain(args.into_iter().map(|arg| {
 478             match get_pass_mode(fx.tcx, sig.abi, arg.layout().ty, false) {
 479                 PassMode::NoPass => unimplemented!("pass mode nopass"),
 480                 PassMode::ByVal(_) => arg.load_value(fx),
 481                 PassMode::ByRef => arg.force_stack(fx),
 482             }
 483         })).collect::<Vec<_>>();
 484
 485     let inst = match trans_operand(fx, func) {
 486         CValue::Func(func, _) => fx.bcx.ins().call(func, &call_args),
 487         func => {
 488             let func = func.load_value(fx);
 489             let sig = fx.bcx.import_signature(cton_sig_from_fn_ty(fx.tcx, fn_ty));
 490             fx.bcx.ins().call_indirect(sig, func, &call_args)
 491         }
 492     };
 493
 494     match output_pass_mode {
 495         PassMode::NoPass => {}
 496         PassMode::ByVal(_) => {
 497             if let Some((ret_place, _)) = destination {
 498                 let results = fx.bcx.inst_results(inst);
 499                 ret_place.write_cvalue(fx, CValue::ByVal(results[0], ret_layout));
 500             }
 501         }
 502         PassMode::ByRef => {}
 503     }
 504     if let Some((_, dest)) = destination {
 505         let ret_ebb = fx.get_ebb(dest);
 506         fx.bcx.ins().jump(ret_ebb, &[]);
 507     } else {
 508         fx.bcx.ins().trap(TrapCode::User(!0));
 509     }
 510 }
 511
 512 pub fn codegen_return(fx: &mut FunctionCx) {
 513     match get_pass_mode(fx.tcx, fx.self_sig().abi, fx.return_type(), true) {
 514         PassMode::NoPass | PassMode::ByRef => {
 515             fx.bcx.ins().return_(&[]);
 516         }
 517         PassMode::ByVal(_) => {
 518             let place = fx.get_local_place(RETURN_PLACE);
 519             let ret_val = place.to_cvalue(fx).load_value(fx);
 520             fx.bcx.ins().return_(&[ret_val]);
 521         }
 522     }
 523 }
 524
 525 fn codegen_intrinsic_call<'a, 'tcx: 'a>(
 526     fx: &mut FunctionCx<'a, 'tcx>,
 527     fn_ty: Ty<'tcx>,
 528     sig: FnSig<'tcx>,
 529     args: &[CValue<'tcx>],
 530     destination: Option<(CPlace<'tcx>, BasicBlock)>,
 531 ) -> bool {
 532     if let TypeVariants::TyFnDef(def_id, substs) = fn_ty.sty {
 533         if sig.abi == Abi::RustIntrinsic {
 534             let intrinsic = fx.tcx.item_name(def_id).as_str();
 535             let intrinsic = &intrinsic[..];
 536
 537             let ret = match destination {
 538                 Some((place, _)) => place,
 539                 None => {
 540                     // Insert non returning intrinsics here
 541                     match intrinsic {
 542                         "abort" => {
 543                             fx.bcx.ins().trap(TrapCode::User(!0 - 1));
 544                         }
 545                         "unreachable" => {
 546                             fx.bcx.ins().trap(TrapCode::User(!0 - 1));
 547                         }
 548                         _ => unimplemented!("unsupported instrinsic {}", intrinsic),
 549                     }
 550                     return true;
 551                 }
 552             };
 553
 554             let nil_ty = fx.tcx.mk_nil();
 555             let u64_layout = fx.layout_of(fx.tcx.types.u64);
 556             let usize_layout = fx.layout_of(fx.tcx.types.usize);
 557
 558             match intrinsic {
 559                 "assume" => {
 560                     assert_eq!(args.len(), 1);
 561                 }
 562                 "arith_offset" => {
 563                     assert_eq!(args.len(), 2);
 564                     let base = args[0].load_value(fx);
 565                     let offset = args[1].load_value(fx);
 566                     let res = fx.bcx.ins().iadd(base, offset);
 567                     let res = CValue::ByVal(res, ret.layout());
 568                     ret.write_cvalue(fx, res);
 569                 }
 570                 "likely" | "unlikely" => {
 571                     assert_eq!(args.len(), 1);
 572                     ret.write_cvalue(fx, args[0]);
 573                 }
 574                 "copy" | "copy_nonoverlapping" => {
 575                     let elem_ty = substs.type_at(0);
 576                     let elem_size: u64 = fx.layout_of(elem_ty).size.bytes();
 577                     let elem_size = fx.bcx.ins().iconst(types::I64, elem_size as i64);
 578                     assert_eq!(args.len(), 3);
 579                     let src = args[0];
 580                     let dst = args[1];
 581                     let count = args[2].load_value(fx);
 582                     let byte_amount = fx.bcx.ins().imul(count, elem_size);
 583                     fx.easy_call(
 584                         "memmove",
 585                         &[dst, src, CValue::ByVal(byte_amount, usize_layout)],
 586                         nil_ty,
 587                     );
 588                 }
 589                 "discriminant_value" => {
 590                     assert_eq!(args.len(), 1);
 591                     let discr = crate::base::trans_get_discriminant(fx, args[0], ret.layout());
 592                     ret.write_cvalue(fx, discr);
 593                 }
 594                 "size_of" => {
 595                     assert_eq!(args.len(), 0);
 596                     let size_of = fx.layout_of(substs.type_at(0)).size.bytes();
 597                     let size_of = CValue::const_val(fx, usize_layout.ty, size_of as i64);
 598                     ret.write_cvalue(fx, size_of);
 599                 }
 600                 "type_id" => {
 601                     assert_eq!(args.len(), 0);
 602                     let type_id = fx.tcx.type_id_hash(substs.type_at(0));
 603                     let type_id = CValue::const_val(fx, u64_layout.ty, type_id as i64);
 604                     ret.write_cvalue(fx, type_id);
 605                 }
 606                 "min_align_of" => {
 607                     assert_eq!(args.len(), 0);
 608                     let min_align = fx.layout_of(substs.type_at(0)).align.abi();
 609                     let min_align = CValue::const_val(fx, usize_layout.ty, min_align as i64);
 610                     ret.write_cvalue(fx, min_align);
 611                 }
 612                 _ if intrinsic.starts_with("unchecked_") => {
 613                     assert_eq!(args.len(), 2);
 614                     let bin_op = match intrinsic {
 615                         "unchecked_div" => BinOp::Div,
 616                         "unchecked_rem" => BinOp::Rem,
 617                         "unchecked_shl" => BinOp::Shl,
 618                         "unchecked_shr" => BinOp::Shr,
 619                         _ => unimplemented!("intrinsic {}", intrinsic),
 620                     };
 621                     let res = match ret.layout().ty.sty {
 622                         TypeVariants::TyUint(_) => crate::base::trans_int_binop(
 623                             fx,
 624                             bin_op,
 625                             args[0],
 626                             args[1],
 627                             ret.layout().ty,
 628                             false,
 629                         ),
 630                         TypeVariants::TyInt(_) => crate::base::trans_int_binop(
 631                             fx,
 632                             bin_op,
 633                             args[0],
 634                             args[1],
 635                             ret.layout().ty,
 636                             true,
 637                         ),
 638                         _ => panic!(),
 639                     };
 640                     ret.write_cvalue(fx, res);
 641                 }
 642                 _ if intrinsic.ends_with("_with_overflow") => {
 643                     assert_eq!(args.len(), 2);
 644                     assert_eq!(args[0].layout().ty, args[1].layout().ty);
 645                     let bin_op = match intrinsic {
 646                         "add_with_overflow" => BinOp::Add,
 647                         "sub_with_overflow" => BinOp::Sub,
 648                         "mul_with_overflow" => BinOp::Mul,
 649                         _ => unimplemented!("intrinsic {}", intrinsic),
 650                     };
 651                     let res = match args[0].layout().ty.sty {
 652                         TypeVariants::TyUint(_) => crate::base::trans_checked_int_binop(
 653                             fx,
 654                             bin_op,
 655                             args[0],
 656                             args[1],
 657                             ret.layout().ty,
 658                             false,
 659                         ),
 660                         TypeVariants::TyInt(_) => crate::base::trans_checked_int_binop(
 661                             fx,
 662                             bin_op,
 663                             args[0],
 664                             args[1],
 665                             ret.layout().ty,
 666                             true,
 667                         ),
 668                         _ => panic!(),
 669                     };
 670                     ret.write_cvalue(fx, res);
 671                 }
 672                 _ if intrinsic.starts_with("overflowing_") => {
 673                     assert_eq!(args.len(), 2);
 674                     assert_eq!(args[0].layout().ty, args[1].layout().ty);
 675                     let bin_op = match intrinsic {
 676                         "overflowing_add" => BinOp::Add,
 677                         "overflowing_sub" => BinOp::Sub,
 678                         "overflowing_mul" => BinOp::Mul,
 679                         _ => unimplemented!("intrinsic {}", intrinsic),
 680                     };
 681                     let res = match args[0].layout().ty.sty {
 682                         TypeVariants::TyUint(_) => crate::base::trans_int_binop(
 683                             fx,
 684                             bin_op,
 685                             args[0],
 686                             args[1],
 687                             ret.layout().ty,
 688                             false,
 689                         ),
 690                         TypeVariants::TyInt(_) => crate::base::trans_int_binop(
 691                             fx,
 692                             bin_op,
 693                             args[0],
 694                             args[1],
 695                             ret.layout().ty,
 696                             true,
 697                         ),
 698                         _ => panic!(),
 699                     };
 700                     ret.write_cvalue(fx, res);
 701                 }
 702                 "offset" => {
 703                     assert_eq!(args.len(), 2);
 704                     let base = args[0].load_value(fx);
 705                     let offset = args[1].load_value(fx);
 706                     let res = fx.bcx.ins().iadd(base, offset);
 707                     ret.write_cvalue(fx, CValue::ByVal(res, args[0].layout()));
 708                 }
 709                 "transmute" => {
 710                     assert_eq!(args.len(), 1);
 711                     let src_ty = substs.type_at(0);
 712                     let dst_ty = substs.type_at(1);
 713                     assert_eq!(args[0].layout().ty, src_ty);
 714                     let addr = args[0].force_stack(fx);
 715                     let dst_layout = fx.layout_of(dst_ty);
 716                     ret.write_cvalue(fx, CValue::ByRef(addr, dst_layout))
 717                 }
 718                 "uninit" => {
 719                     assert_eq!(args.len(), 0);
 720                     let ty = substs.type_at(0);
 721                     let layout = fx.layout_of(ty);
 722                     let stack_slot = fx.bcx.create_stack_slot(StackSlotData {
 723                         kind: StackSlotKind::ExplicitSlot,
 724                         size: layout.size.bytes() as u32,
 725                         offset: None,
 726                     });
 727
 728                     let uninit_place = CPlace::from_stack_slot(fx, stack_slot, ty);
 729                     let uninit_val = uninit_place.to_cvalue(fx);
 730                     ret.write_cvalue(fx, uninit_val);
 731                 }
 732                 "ctlz" | "ctlz_nonzero" => {
 733                     assert_eq!(args.len(), 1);
 734                     let arg = args[0].load_value(fx);
 735                     let res = CValue::ByVal(fx.bcx.ins().clz(arg), args[0].layout());
 736                     ret.write_cvalue(fx, res);
 737                 }
 738                 "cttz" | "cttz_nonzero" => {
 739                     assert_eq!(args.len(), 1);
 740                     let arg = args[0].load_value(fx);
 741                     let res = CValue::ByVal(fx.bcx.ins().clz(arg), args[0].layout());
 742                     ret.write_cvalue(fx, res);
 743                 }
 744                 "ctpop" => {
 745                     assert_eq!(args.len(), 1);
 746                     let arg = args[0].load_value(fx);
 747                     let res = CValue::ByVal(fx.bcx.ins().popcnt(arg), args[0].layout());
 748                     ret.write_cvalue(fx, res);
 749                 }
 750                 _ => unimpl!("unsupported intrinsic {}", intrinsic),
 751             }
 752
 753             if let Some((_, dest)) = destination {
 754                 let ret_ebb = fx.get_ebb(dest);
 755                 fx.bcx.ins().jump(ret_ebb, &[]);
 756             } else {
 757                 fx.bcx.ins().trap(TrapCode::User(!0));
 758             }
 759             return true;
 760         }
 761     }
 762
 763     false
 764 }