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     (tcx.symbol_name(inst).as_str().to_string(), sig)
 164 }
 165
 166 impl<'a, 'tcx: 'a> CodegenCx<'a, 'tcx, CurrentBackend> {
 167     pub fn predefine_function(&mut self, inst: Instance<'tcx>) -> (FuncId, Function) {
 168         let (name, sig) = crate::abi::get_function_name_and_sig(self.tcx, inst);
 169         let func_id = self
 170             .module
 171             .declare_function(&name, Linkage::Export, &sig)
 172             .unwrap();
 173         let func =
 174             Function::with_name_signature(ExternalName::user(0, func_id.index() as u32), sig);
 175         (func_id, func)
 176     }
 177 }
 178
 179 impl<'a, 'tcx: 'a> FunctionCx<'a, 'tcx> {
 180     /// Instance must be monomorphized
 181     pub fn get_function_ref(&mut self, inst: Instance<'tcx>) -> FuncRef {
 182         let (name, sig) = get_function_name_and_sig(self.tcx, inst);
 183         let func_id = self
 184             .module
 185             .declare_function(&name, Linkage::Import, &sig)
 186             .unwrap();
 187         self.module
 188             .declare_func_in_func(func_id, &mut self.bcx.func)
 189     }
 190
 191     fn lib_call(
 192         &mut self,
 193         name: &str,
 194         input_tys: Vec<types::Type>,
 195         output_ty: Option<types::Type>,
 196         args: &[Value],
 197     ) -> Option<Value> {
 198         let sig = Signature {
 199             params: input_tys.iter().cloned().map(AbiParam::new).collect(),
 200             returns: vec![AbiParam::new(output_ty.unwrap_or(types::VOID))],
 201             call_conv: CallConv::SystemV,
 202             argument_bytes: None,
 203         };
 204         let func_id = self
 205             .module
 206             .declare_function(&name, Linkage::Import, &sig)
 207             .unwrap();
 208         let func_ref = self
 209             .module
 210             .declare_func_in_func(func_id, &mut self.bcx.func);
 211         let call_inst = self.bcx.ins().call(func_ref, args);
 212         if output_ty.is_none() {
 213             return None;
 214         }
 215         let results = self.bcx.inst_results(call_inst);
 216         assert_eq!(results.len(), 1);
 217         Some(results[0])
 218     }
 219
 220     pub fn easy_call(
 221         &mut self,
 222         name: &str,
 223         args: &[CValue<'tcx>],
 224         return_ty: Ty<'tcx>,
 225     ) -> CValue<'tcx> {
 226         let (input_tys, args): (Vec<_>, Vec<_>) = args
 227             .into_iter()
 228             .map(|arg| {
 229                 (
 230                     self.cton_type(arg.layout().ty).unwrap(),
 231                     arg.load_value(self),
 232                 )
 233             }).unzip();
 234         let return_layout = self.layout_of(return_ty);
 235         let return_ty = if let TypeVariants::TyTuple(tup) = return_ty.sty {
 236             if !tup.is_empty() {
 237                 bug!("easy_call( (...) -> <non empty tuple> ) is not allowed");
 238             }
 239             None
 240         } else {
 241             Some(self.cton_type(return_ty).unwrap())
 242         };
 243         if let Some(val) = self.lib_call(name, input_tys, return_ty, &args) {
 244             CValue::ByVal(val, return_layout)
 245         } else {
 246             CValue::ByRef(self.bcx.ins().iconst(types::I64, 0), return_layout)
 247         }
 248     }
 249
 250     fn self_sig(&self) -> FnSig<'tcx> {
 251         ty_fn_sig(self.tcx, self.instance.ty(self.tcx))
 252     }
 253
 254     fn return_type(&self) -> Ty<'tcx> {
 255         self.self_sig().output()
 256     }
 257 }
 258
 259 pub fn codegen_fn_prelude<'a, 'tcx: 'a>(fx: &mut FunctionCx<'a, 'tcx>, start_ebb: Ebb) {
 260     let ssa_analyzed = crate::analyze::analyze(fx);
 261     fx.tcx.sess.warn(&format!("ssa {:?}", ssa_analyzed));
 262
 263     match fx.self_sig().abi {
 264         Abi::Rust | Abi::RustCall => {}
 265         _ => unimplemented!("declared function with non \"rust\" or \"rust-call\" abi"),
 266     }
 267
 268     let ret_layout = fx.layout_of(fx.return_type());
 269     let output_pass_mode = get_pass_mode(fx.tcx, fx.self_sig().abi, fx.return_type(), true);
 270     let ret_param = match output_pass_mode {
 271         PassMode::NoPass => None,
 272         PassMode::ByVal(_) => None,
 273         PassMode::ByRef => Some(fx.bcx.append_ebb_param(start_ebb, types::I64)),
 274     };
 275
 276     enum ArgKind {
 277         Normal(Value),
 278         Spread(Vec<Value>),
 279     }
 280
 281     let func_params = fx
 282         .mir
 283         .args_iter()
 284         .map(|local| {
 285             let arg_ty = fx.monomorphize(&fx.mir.local_decls[local].ty);
 286
 287             // Adapted from https://github.com/rust-lang/rust/blob/145155dc96757002c7b2e9de8489416e2fdbbd57/src/librustc_codegen_llvm/mir/mod.rs#L442-L482
 288             if Some(local) == fx.mir.spread_arg {
 289                 // This argument (e.g. the last argument in the "rust-call" ABI)
 290                 // is a tuple that was spread at the ABI level and now we have
 291                 // to reconstruct it into a tuple local variable, from multiple
 292                 // individual function arguments.
 293
 294                 let tupled_arg_tys = match arg_ty.sty {
 295                     ty::TyTuple(ref tys) => tys,
 296                     _ => bug!("spread argument isn't a tuple?! but {:?}", arg_ty),
 297                 };
 298
 299                 let mut ebb_params = Vec::new();
 300                 for arg_ty in tupled_arg_tys.iter() {
 301                     let cton_type =
 302                         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 =
 309                     get_pass_mode(fx.tcx, fx.self_sig().abi, arg_ty, false).get_param_ty(fx);
 310                 (
 311                     local,
 312                     ArgKind::Normal(fx.bcx.append_ebb_param(start_ebb, cton_type)),
 313                     arg_ty,
 314                 )
 315             }
 316         }).collect::<Vec<(Local, ArgKind, Ty)>>();
 317
 318     match output_pass_mode {
 319         PassMode::NoPass => {
 320             let null = fx.bcx.ins().iconst(types::I64, 0);
 321             //unimplemented!("pass mode nopass");
 322             fx.local_map.insert(
 323                 RETURN_PLACE,
 324                 CPlace::Addr(null, fx.layout_of(fx.return_type())),
 325             );
 326         }
 327         PassMode::ByVal(ret_ty) => {
 328             let var = Variable(RETURN_PLACE);
 329             fx.bcx.declare_var(var, ret_ty);
 330             fx.local_map
 331                 .insert(RETURN_PLACE, CPlace::Var(var, ret_layout));
 332         }
 333         PassMode::ByRef => {
 334             fx.local_map
 335                 .insert(RETURN_PLACE, CPlace::Addr(ret_param.unwrap(), ret_layout));
 336         }
 337     }
 338
 339     for (local, arg_kind, ty) in func_params {
 340         let layout = fx.layout_of(ty);
 341
 342         if let ArgKind::Normal(ebb_param) = arg_kind {
 343             if !ssa_analyzed
 344                 .get(&local)
 345                 .unwrap()
 346                 .contains(crate::analyze::Flags::NOT_SSA)
 347             {
 348                 let var = Variable(local);
 349                 fx.bcx.declare_var(var, fx.cton_type(ty).unwrap());
 350                 match get_pass_mode(fx.tcx, fx.self_sig().abi, ty, false) {
 351                     PassMode::NoPass => unimplemented!("pass mode nopass"),
 352                     PassMode::ByVal(_) => fx.bcx.def_var(var, ebb_param),
 353                     PassMode::ByRef => {
 354                         let val = CValue::ByRef(ebb_param, fx.layout_of(ty)).load_value(fx);
 355                         fx.bcx.def_var(var, val);
 356                     }
 357                 }
 358                 fx.local_map.insert(local, CPlace::Var(var, layout));
 359                 continue;
 360             }
 361         }
 362
 363         let stack_slot = fx.bcx.create_stack_slot(StackSlotData {
 364             kind: StackSlotKind::ExplicitSlot,
 365             size: layout.size.bytes() as u32,
 366             offset: None,
 367         });
 368
 369         let place = CPlace::from_stack_slot(fx, stack_slot, ty);
 370
 371         match arg_kind {
 372             ArgKind::Normal(ebb_param) => match get_pass_mode(fx.tcx, fx.self_sig().abi, ty, false)
 373             {
 374                 PassMode::NoPass => unimplemented!("pass mode nopass"),
 375                 PassMode::ByVal(_) => {
 376                     place.write_cvalue(fx, CValue::ByVal(ebb_param, place.layout()))
 377                 }
 378                 PassMode::ByRef => place.write_cvalue(fx, CValue::ByRef(ebb_param, place.layout())),
 379             },
 380             ArgKind::Spread(ebb_params) => {
 381                 for (i, ebb_param) in ebb_params.into_iter().enumerate() {
 382                     let sub_place = place.place_field(fx, mir::Field::new(i));
 383                     match get_pass_mode(fx.tcx, fx.self_sig().abi, sub_place.layout().ty, false) {
 384                         PassMode::NoPass => unimplemented!("pass mode nopass"),
 385                         PassMode::ByVal(_) => {
 386                             sub_place.write_cvalue(fx, CValue::ByVal(ebb_param, sub_place.layout()))
 387                         }
 388                         PassMode::ByRef => {
 389                             sub_place.write_cvalue(fx, CValue::ByRef(ebb_param, sub_place.layout()))
 390                         }
 391                     }
 392                 }
 393             }
 394         }
 395         fx.local_map.insert(local, place);
 396     }
 397
 398     for local in fx.mir.vars_and_temps_iter() {
 399         let ty = fx.mir.local_decls[local].ty;
 400         let layout = fx.layout_of(ty);
 401
 402         let place = if ssa_analyzed
 403             .get(&local)
 404             .unwrap()
 405             .contains(crate::analyze::Flags::NOT_SSA)
 406         {
 407             let stack_slot = fx.bcx.create_stack_slot(StackSlotData {
 408                 kind: StackSlotKind::ExplicitSlot,
 409                 size: layout.size.bytes() as u32,
 410                 offset: None,
 411             });
 412             CPlace::from_stack_slot(fx, stack_slot, ty)
 413         } else {
 414             let var = Variable(local);
 415             fx.bcx.declare_var(var, fx.cton_type(ty).unwrap());
 416             CPlace::Var(var, layout)
 417         };
 418
 419         fx.local_map.insert(local, place);
 420     }
 421 }
 422
 423 pub fn codegen_call<'a, 'tcx: 'a>(
 424     fx: &mut FunctionCx<'a, 'tcx>,
 425     func: &Operand<'tcx>,
 426     args: &[Operand<'tcx>],
 427     destination: &Option<(Place<'tcx>, BasicBlock)>,
 428 ) {
 429     let fn_ty = fx.monomorphize(&func.ty(&fx.mir.local_decls, fx.tcx));
 430     let sig = ty_fn_sig(fx.tcx, fn_ty);
 431
 432     // Unpack arguments tuple for closures
 433     let args = if sig.abi == Abi::RustCall {
 434         assert_eq!(args.len(), 2, "rust-call abi requires two arguments");
 435         let self_arg = trans_operand(fx, &args[0]);
 436         let pack_arg = trans_operand(fx, &args[1]);
 437         let mut args = Vec::new();
 438         args.push(self_arg);
 439         match pack_arg.layout().ty.sty {
 440             ty::TyTuple(ref tupled_arguments) => {
 441                 for (i, _) in tupled_arguments.iter().enumerate() {
 442                     args.push(pack_arg.value_field(fx, mir::Field::new(i)));
 443                 }
 444             }
 445             _ => bug!("argument to function with \"rust-call\" ABI is not a tuple"),
 446         }
 447         println!(
 448             "{:?} {:?}",
 449             pack_arg.layout().ty,
 450             args.iter().map(|a| a.layout().ty).collect::<Vec<_>>()
 451         );
 452         args
 453     } else {
 454         args.into_iter()
 455             .map(|arg| trans_operand(fx, arg))
 456             .collect::<Vec<_>>()
 457     };
 458
 459     let destination = destination
 460         .as_ref()
 461         .map(|(place, bb)| (trans_place(fx, place), *bb));
 462
 463     if codegen_intrinsic_call(fx, fn_ty, sig, &args, destination) {
 464         return;
 465     }
 466
 467     let ret_layout = fx.layout_of(sig.output());
 468
 469     let output_pass_mode = get_pass_mode(fx.tcx, sig.abi, sig.output(), true);
 470     println!("{:?}", output_pass_mode);
 471     let return_ptr = match output_pass_mode {
 472         PassMode::NoPass => None,
 473         PassMode::ByRef => match destination {
 474             Some((place, _)) => Some(place.expect_addr()),
 475             None => Some(fx.bcx.ins().iconst(types::I64, 0)),
 476         },
 477         PassMode::ByVal(_) => None,
 478     };
 479
 480     let call_args: Vec<Value> = return_ptr
 481         .into_iter()
 482         .chain(args.into_iter().map(|arg| {
 483             match get_pass_mode(fx.tcx, sig.abi, arg.layout().ty, false) {
 484                 PassMode::NoPass => unimplemented!("pass mode nopass"),
 485                 PassMode::ByVal(_) => arg.load_value(fx),
 486                 PassMode::ByRef => arg.force_stack(fx),
 487             }
 488         })).collect::<Vec<_>>();
 489
 490     let inst = match trans_operand(fx, func) {
 491         CValue::Func(func, _) => fx.bcx.ins().call(func, &call_args),
 492         func => {
 493             let func = func.load_value(fx);
 494             let sig = fx.bcx.import_signature(cton_sig_from_fn_ty(fx.tcx, fn_ty));
 495             fx.bcx.ins().call_indirect(sig, func, &call_args)
 496         }
 497     };
 498
 499     match output_pass_mode {
 500         PassMode::NoPass => {}
 501         PassMode::ByVal(_) => {
 502             if let Some((ret_place, _)) = destination {
 503                 let results = fx.bcx.inst_results(inst);
 504                 ret_place.write_cvalue(fx, CValue::ByVal(results[0], ret_layout));
 505             }
 506         }
 507         PassMode::ByRef => {}
 508     }
 509     if let Some((_, dest)) = destination {
 510         let ret_ebb = fx.get_ebb(dest);
 511         fx.bcx.ins().jump(ret_ebb, &[]);
 512     } else {
 513         fx.bcx.ins().trap(TrapCode::User(!0));
 514     }
 515 }
 516
 517 pub fn codegen_return(fx: &mut FunctionCx) {
 518     match get_pass_mode(fx.tcx, fx.self_sig().abi, fx.return_type(), true) {
 519         PassMode::NoPass | PassMode::ByRef => {
 520             fx.bcx.ins().return_(&[]);
 521         }
 522         PassMode::ByVal(_) => {
 523             let place = fx.get_local_place(RETURN_PLACE);
 524             let ret_val = place.to_cvalue(fx).load_value(fx);
 525             fx.bcx.ins().return_(&[ret_val]);
 526         }
 527     }
 528 }
 529
 530 fn codegen_intrinsic_call<'a, 'tcx: 'a>(
 531     fx: &mut FunctionCx<'a, 'tcx>,
 532     fn_ty: Ty<'tcx>,
 533     sig: FnSig<'tcx>,
 534     args: &[CValue<'tcx>],
 535     destination: Option<(CPlace<'tcx>, BasicBlock)>,
 536 ) -> bool {
 537     if let TypeVariants::TyFnDef(def_id, substs) = fn_ty.sty {
 538         if sig.abi == Abi::RustIntrinsic {
 539             let intrinsic = fx.tcx.item_name(def_id).as_str();
 540             let intrinsic = &intrinsic[..];
 541
 542             let ret = match destination {
 543                 Some((place, _)) => place,
 544                 None => {
 545                     // Insert non returning intrinsics here
 546                     match intrinsic {
 547                         "abort" => {
 548                             fx.bcx.ins().trap(TrapCode::User(!0 - 1));
 549                         }
 550                         "unreachable" => {
 551                             fx.bcx.ins().trap(TrapCode::User(!0 - 1));
 552                         }
 553                         _ => unimplemented!("unsupported instrinsic {}", intrinsic),
 554                     }
 555                     return true;
 556                 }
 557             };
 558
 559             let nil_ty = fx.tcx.mk_nil();
 560             let u64_layout = fx.layout_of(fx.tcx.types.u64);
 561             let usize_layout = fx.layout_of(fx.tcx.types.usize);
 562
 563             match intrinsic {
 564                 "assume" => {
 565                     assert_eq!(args.len(), 1);
 566                 }
 567                 "arith_offset" => {
 568                     assert_eq!(args.len(), 2);
 569                     let base = args[0].load_value(fx);
 570                     let offset = args[1].load_value(fx);
 571                     let res = fx.bcx.ins().iadd(base, offset);
 572                     let res = CValue::ByVal(res, ret.layout());
 573                     ret.write_cvalue(fx, res);
 574                 }
 575                 "likely" | "unlikely" => {
 576                     assert_eq!(args.len(), 1);
 577                     ret.write_cvalue(fx, args[0]);
 578                 }
 579                 "copy" | "copy_nonoverlapping" => {
 580                     let elem_ty = substs.type_at(0);
 581                     let elem_size: u64 = fx.layout_of(elem_ty).size.bytes();
 582                     let elem_size = fx.bcx.ins().iconst(types::I64, 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                 "type_id" => {
 606                     assert_eq!(args.len(), 0);
 607                     let type_id = fx.tcx.type_id_hash(substs.type_at(0));
 608                     let type_id = CValue::const_val(fx, u64_layout.ty, type_id as i64);
 609                     ret.write_cvalue(fx, type_id);
 610                 }
 611                 "min_align_of" => {
 612                     assert_eq!(args.len(), 0);
 613                     let min_align = fx.layout_of(substs.type_at(0)).align.abi();
 614                     let min_align = CValue::const_val(fx, usize_layout.ty, min_align as i64);
 615                     ret.write_cvalue(fx, min_align);
 616                 }
 617                 _ if intrinsic.starts_with("unchecked_") => {
 618                     assert_eq!(args.len(), 2);
 619                     let bin_op = match intrinsic {
 620                         "unchecked_div" => BinOp::Div,
 621                         "unchecked_rem" => BinOp::Rem,
 622                         "unchecked_shl" => BinOp::Shl,
 623                         "unchecked_shr" => BinOp::Shr,
 624                         _ => unimplemented!("intrinsic {}", intrinsic),
 625                     };
 626                     let res = match ret.layout().ty.sty {
 627                         TypeVariants::TyUint(_) => crate::base::trans_int_binop(
 628                             fx,
 629                             bin_op,
 630                             args[0],
 631                             args[1],
 632                             ret.layout().ty,
 633                             false,
 634                         ),
 635                         TypeVariants::TyInt(_) => crate::base::trans_int_binop(
 636                             fx,
 637                             bin_op,
 638                             args[0],
 639                             args[1],
 640                             ret.layout().ty,
 641                             true,
 642                         ),
 643                         _ => panic!(),
 644                     };
 645                     ret.write_cvalue(fx, res);
 646                 }
 647                 _ if intrinsic.ends_with("_with_overflow") => {
 648                     assert_eq!(args.len(), 2);
 649                     assert_eq!(args[0].layout().ty, args[1].layout().ty);
 650                     let bin_op = match intrinsic {
 651                         "add_with_overflow" => BinOp::Add,
 652                         "sub_with_overflow" => BinOp::Sub,
 653                         "mul_with_overflow" => BinOp::Mul,
 654                         _ => unimplemented!("intrinsic {}", intrinsic),
 655                     };
 656                     let res = match args[0].layout().ty.sty {
 657                         TypeVariants::TyUint(_) => crate::base::trans_checked_int_binop(
 658                             fx,
 659                             bin_op,
 660                             args[0],
 661                             args[1],
 662                             ret.layout().ty,
 663                             false,
 664                         ),
 665                         TypeVariants::TyInt(_) => crate::base::trans_checked_int_binop(
 666                             fx,
 667                             bin_op,
 668                             args[0],
 669                             args[1],
 670                             ret.layout().ty,
 671                             true,
 672                         ),
 673                         _ => panic!(),
 674                     };
 675                     ret.write_cvalue(fx, res);
 676                 }
 677                 _ if intrinsic.starts_with("overflowing_") => {
 678                     assert_eq!(args.len(), 2);
 679                     assert_eq!(args[0].layout().ty, args[1].layout().ty);
 680                     let bin_op = match intrinsic {
 681                         "overflowing_add" => BinOp::Add,
 682                         "overflowing_sub" => BinOp::Sub,
 683                         "overflowing_mul" => BinOp::Mul,
 684                         _ => unimplemented!("intrinsic {}", intrinsic),
 685                     };
 686                     let res = match args[0].layout().ty.sty {
 687                         TypeVariants::TyUint(_) => crate::base::trans_int_binop(
 688                             fx,
 689                             bin_op,
 690                             args[0],
 691                             args[1],
 692                             ret.layout().ty,
 693                             false,
 694                         ),
 695                         TypeVariants::TyInt(_) => crate::base::trans_int_binop(
 696                             fx,
 697                             bin_op,
 698                             args[0],
 699                             args[1],
 700                             ret.layout().ty,
 701                             true,
 702                         ),
 703                         _ => panic!(),
 704                     };
 705                     ret.write_cvalue(fx, res);
 706                 }
 707                 "offset" => {
 708                     assert_eq!(args.len(), 2);
 709                     let base = args[0].load_value(fx);
 710                     let offset = args[1].load_value(fx);
 711                     let res = fx.bcx.ins().iadd(base, offset);
 712                     ret.write_cvalue(fx, CValue::ByVal(res, args[0].layout()));
 713                 }
 714                 "transmute" => {
 715                     assert_eq!(args.len(), 1);
 716                     let src_ty = substs.type_at(0);
 717                     let dst_ty = substs.type_at(1);
 718                     assert_eq!(args[0].layout().ty, src_ty);
 719                     let addr = args[0].force_stack(fx);
 720                     let dst_layout = fx.layout_of(dst_ty);
 721                     ret.write_cvalue(fx, CValue::ByRef(addr, dst_layout))
 722                 }
 723                 "uninit" => {
 724                     assert_eq!(args.len(), 0);
 725                     let ty = substs.type_at(0);
 726                     let layout = fx.layout_of(ty);
 727                     let stack_slot = fx.bcx.create_stack_slot(StackSlotData {
 728                         kind: StackSlotKind::ExplicitSlot,
 729                         size: layout.size.bytes() as u32,
 730                         offset: None,
 731                     });
 732
 733                     let uninit_place = CPlace::from_stack_slot(fx, stack_slot, ty);
 734                     let uninit_val = uninit_place.to_cvalue(fx);
 735                     ret.write_cvalue(fx, uninit_val);
 736                 }
 737                 "ctlz" | "ctlz_nonzero" => {
 738                     assert_eq!(args.len(), 1);
 739                     let arg = args[0].load_value(fx);
 740                     let res = CValue::ByVal(fx.bcx.ins().clz(arg), args[0].layout());
 741                     ret.write_cvalue(fx, res);
 742                 }
 743                 "cttz" | "cttz_nonzero" => {
 744                     assert_eq!(args.len(), 1);
 745                     let arg = args[0].load_value(fx);
 746                     let res = CValue::ByVal(fx.bcx.ins().clz(arg), args[0].layout());
 747                     ret.write_cvalue(fx, res);
 748                 }
 749                 "ctpop" => {
 750                     assert_eq!(args.len(), 1);
 751                     let arg = args[0].load_value(fx);
 752                     let res = CValue::ByVal(fx.bcx.ins().popcnt(arg), args[0].layout());
 753                     ret.write_cvalue(fx, res);
 754                 }
 755                 _ => unimpl!("unsupported intrinsic {}", intrinsic),
 756             }
 757
 758             if let Some((_, dest)) = destination {
 759                 let ret_ebb = fx.get_ebb(dest);
 760                 fx.bcx.ins().jump(ret_ebb, &[]);
 761             } else {
 762                 fx.bcx.ins().trap(TrapCode::User(!0));
 763             }
 764             return true;
 765         }
 766     }
 767
 768     false
 769 }