src/base.rs

   1 use crate::prelude::*;
   2
   3 struct PrintOnPanic<F: Fn() -> String>(F);
   4 impl<F: Fn() -> String> Drop for PrintOnPanic<F> {
   5     fn drop(&mut self) {
   6         if ::std::thread::panicking() {
   7             println!("{}", (self.0)());
   8         }
   9     }
  10 }
  11
  12 pub fn trans_mono_item<'a, 'clif, 'tcx: 'a, B: Backend + 'static>(
  13     cx: &mut crate::CodegenCx<'a, 'clif, 'tcx, B>,
  14     mono_item: MonoItem<'tcx>,
  15     linkage: Linkage,
  16 ) {
  17     let tcx = cx.tcx;
  18     match mono_item {
  19         MonoItem::Fn(inst) => {
  20             let _inst_guard =
  21                 PrintOnPanic(|| format!("{:?} {}", inst, tcx.symbol_name(inst).as_str()));
  22             debug_assert!(!inst.substs.needs_infer());
  23             let _mir_guard = PrintOnPanic(|| {
  24                 match inst.def {
  25                     InstanceDef::Item(_)
  26                     | InstanceDef::DropGlue(_, _)
  27                     | InstanceDef::Virtual(_, _)
  28                         if inst.def_id().krate == LOCAL_CRATE =>
  29                     {
  30                         let mut mir = ::std::io::Cursor::new(Vec::new());
  31                         crate::rustc_mir::util::write_mir_pretty(
  32                             tcx,
  33                             Some(inst.def_id()),
  34                             &mut mir,
  35                         )
  36                         .unwrap();
  37                         String::from_utf8(mir.into_inner()).unwrap()
  38                     }
  39                     _ => {
  40                         // FIXME fix write_mir_pretty for these instances
  41                         format!("{:#?}", tcx.instance_mir(inst.def))
  42                     }
  43                 }
  44             });
  45
  46             trans_fn(cx, inst, linkage);
  47         }
  48         MonoItem::Static(def_id) => {
  49             crate::constant::codegen_static(&mut cx.ccx, def_id);
  50         }
  51         MonoItem::GlobalAsm(node_id) => tcx
  52             .sess
  53             .fatal(&format!("Unimplemented global asm mono item {:?}", node_id)),
  54     }
  55 }
  56
  57 fn trans_fn<'a, 'clif, 'tcx: 'a, B: Backend + 'static>(
  58     cx: &mut crate::CodegenCx<'a, 'clif, 'tcx, B>,
  59     instance: Instance<'tcx>,
  60     linkage: Linkage,
  61 ) {
  62     let tcx = cx.tcx;
  63
  64     // Step 1. Get mir
  65     let mir = tcx.instance_mir(instance.def);
  66
  67     // Step 2. Check fn sig for u128 and i128 and replace those functions with a trap.
  68     {
  69         // FIXME implement u128 and i128 support
  70
  71         // Step 2a. Check sig for u128 and i128
  72         let fn_sig = tcx.normalize_erasing_late_bound_regions(ParamEnv::reveal_all(), &instance.fn_sig(tcx));
  73
  74         struct UI128Visitor<'a, 'tcx: 'a>(TyCtxt<'a, 'tcx, 'tcx>, bool);
  75
  76         impl<'a, 'tcx: 'a> rustc::ty::fold::TypeVisitor<'tcx> for UI128Visitor<'a, 'tcx> {
  77             fn visit_ty(&mut self, t: Ty<'tcx>) -> bool {
  78                 if t.sty == self.0.types.u128.sty || t.sty == self.0.types.i128.sty {
  79                     self.1 = true;
  80                     return false; // stop visiting
  81                 }
  82
  83                 t.super_visit_with(self)
  84             }
  85         }
  86
  87         let mut visitor = UI128Visitor(tcx, false);
  88         fn_sig.visit_with(&mut visitor);
  89
  90         // Step 2b. If found replace function with a trap.
  91         if visitor.1 {
  92             tcx.sess.warn("u128 and i128 are not yet supported. \
  93             Functions using these as args will be replaced with a trap.");
  94
  95             // Step 2b1. Declare function with fake signature
  96             let sig = Signature {
  97                 params: vec![AbiParam::new(types::INVALID)],
  98                 returns: vec![],
  99                 call_conv: CallConv::Fast,
 100             };
 101             let name = tcx.symbol_name(instance).as_str();
 102             let func_id = cx.module.declare_function(&*name, linkage, &sig).unwrap();
 103
 104             // Step 2b2. Create trapping function
 105             let mut func = Function::with_name_signature(ExternalName::user(0, 0), sig);
 106             let mut func_ctx = FunctionBuilderContext::new();
 107             let mut bcx = FunctionBuilder::new(&mut func, &mut func_ctx);
 108             let start_ebb = bcx.create_ebb();
 109             bcx.append_ebb_params_for_function_params(start_ebb);
 110             bcx.switch_to_block(start_ebb);
 111             crate::trap::trap_unreachable(&mut bcx);
 112             bcx.seal_all_blocks();
 113             bcx.finalize();
 114
 115             // Step 2b3. Define function
 116             cx.caches.context.func = func;
 117             cx.module
 118                 .define_function(func_id, &mut cx.caches.context)
 119                 .unwrap();
 120             cx.caches.context.clear();
 121             return;
 122         }
 123     }
 124
 125     // Step 3. Declare function
 126     let (name, sig) = get_function_name_and_sig(tcx, instance, false);
 127     let func_id = cx.module.declare_function(&name, linkage, &sig).unwrap();
 128     let mut debug_context = cx
 129         .debug_context
 130         .as_mut()
 131         .map(|debug_context| FunctionDebugContext::new(tcx, debug_context, mir, &name, &sig));
 132
 133     // Step 4. Make FunctionBuilder
 134     let mut func = Function::with_name_signature(ExternalName::user(0, 0), sig);
 135     let mut func_ctx = FunctionBuilderContext::new();
 136     let mut bcx = FunctionBuilder::new(&mut func, &mut func_ctx);
 137
 138     // Step 5. Predefine ebb's
 139     let start_ebb = bcx.create_ebb();
 140     let mut ebb_map: HashMap<BasicBlock, Ebb> = HashMap::new();
 141     for (bb, _bb_data) in mir.basic_blocks().iter_enumerated() {
 142         ebb_map.insert(bb, bcx.create_ebb());
 143     }
 144
 145     // Step 6. Make FunctionCx
 146     let pointer_type = cx.module.target_config().pointer_type();
 147     let clif_comments = crate::pretty_clif::CommentWriter::new(tcx, instance);
 148
 149     let mut fx = FunctionCx {
 150         tcx,
 151         module: cx.module,
 152         pointer_type,
 153
 154         instance,
 155         mir,
 156
 157         bcx,
 158         ebb_map,
 159         local_map: HashMap::new(),
 160
 161         clif_comments,
 162         constants: &mut cx.ccx,
 163         caches: &mut cx.caches,
 164         source_info_set: indexmap::IndexSet::new(),
 165     };
 166
 167     // Step 7. Codegen function
 168     with_unimpl_span(fx.mir.span, || {
 169         crate::abi::codegen_fn_prelude(&mut fx, start_ebb);
 170         codegen_fn_content(&mut fx);
 171     });
 172     let source_info_set = fx.source_info_set.clone();
 173
 174     // Step 8. Write function to file for debugging
 175     #[cfg(debug_assertions)]
 176     fx.write_clif_file();
 177
 178     // Step 9. Verify function
 179     verify_func(tcx, fx.clif_comments, &func);
 180
 181     // Step 10. Define function
 182     cx.caches.context.func = func;
 183     cx.module
 184         .define_function(func_id, &mut cx.caches.context)
 185         .unwrap();
 186
 187     // Step 11. Define debuginfo for function
 188     let context = &cx.caches.context;
 189     let isa = cx.module.isa();
 190     debug_context
 191         .as_mut()
 192         .map(|x| x.define(tcx, context, isa, &source_info_set));
 193
 194     // Step 12. Clear context to make it usable for the next function
 195     cx.caches.context.clear();
 196 }
 197
 198 fn verify_func(tcx: TyCtxt, writer: crate::pretty_clif::CommentWriter, func: &Function) {
 199     let flags = settings::Flags::new(settings::builder());
 200     match ::cranelift::codegen::verify_function(&func, &flags) {
 201         Ok(_) => {}
 202         Err(err) => {
 203             tcx.sess.err(&format!("{:?}", err));
 204             let pretty_error = ::cranelift::codegen::print_errors::pretty_verifier_error(
 205                 &func,
 206                 None,
 207                 Some(Box::new(&writer)),
 208                 err,
 209             );
 210             tcx.sess
 211                 .fatal(&format!("cranelift verify error:\n{}", pretty_error));
 212         }
 213     }
 214 }
 215
 216 fn codegen_fn_content<'a, 'tcx: 'a>(fx: &mut FunctionCx<'a, 'tcx, impl Backend>) {
 217     for (bb, bb_data) in fx.mir.basic_blocks().iter_enumerated() {
 218         if bb_data.is_cleanup {
 219             // Unwinding after panicking is not supported
 220             continue;
 221         }
 222
 223         let ebb = fx.get_ebb(bb);
 224         fx.bcx.switch_to_block(ebb);
 225
 226         fx.bcx.ins().nop();
 227         for stmt in &bb_data.statements {
 228             fx.set_debug_loc(stmt.source_info);
 229             trans_stmt(fx, ebb, stmt);
 230         }
 231
 232         #[cfg(debug_assertions)]
 233         {
 234             let mut terminator_head = "\n".to_string();
 235             bb_data
 236                 .terminator()
 237                 .kind
 238                 .fmt_head(&mut terminator_head)
 239                 .unwrap();
 240             let inst = fx.bcx.func.layout.last_inst(ebb).unwrap();
 241             fx.add_comment(inst, terminator_head);
 242         }
 243
 244         fx.set_debug_loc(bb_data.terminator().source_info);
 245
 246         match &bb_data.terminator().kind {
 247             TerminatorKind::Goto { target } => {
 248                 let ebb = fx.get_ebb(*target);
 249                 fx.bcx.ins().jump(ebb, &[]);
 250             }
 251             TerminatorKind::Return => {
 252                 crate::abi::codegen_return(fx);
 253             }
 254             TerminatorKind::Assert {
 255                 cond,
 256                 expected,
 257                 msg: _,
 258                 target,
 259                 cleanup: _,
 260             } => {
 261                 let cond = trans_operand(fx, cond).load_scalar(fx);
 262                 // TODO HACK brz/brnz for i8/i16 is not yet implemented
 263                 let cond = fx.bcx.ins().uextend(types::I32, cond);
 264                 let target = fx.get_ebb(*target);
 265                 if *expected {
 266                     fx.bcx.ins().brnz(cond, target, &[]);
 267                 } else {
 268                     fx.bcx.ins().brz(cond, target, &[]);
 269                 };
 270                 trap_panic(&mut fx.bcx);
 271             }
 272
 273             TerminatorKind::SwitchInt {
 274                 discr,
 275                 switch_ty: _,
 276                 values,
 277                 targets,
 278             } => {
 279                 let discr = trans_operand(fx, discr).load_scalar(fx);
 280                 let mut switch = ::cranelift::frontend::Switch::new();
 281                 for (i, value) in values.iter().enumerate() {
 282                     let ebb = fx.get_ebb(targets[i]);
 283                     switch.set_entry(*value as u64, ebb);
 284                 }
 285                 let otherwise_ebb = fx.get_ebb(targets[targets.len() - 1]);
 286                 switch.emit(&mut fx.bcx, discr, otherwise_ebb);
 287             }
 288             TerminatorKind::Call {
 289                 func,
 290                 args,
 291                 destination,
 292                 cleanup: _,
 293                 from_hir_call: _,
 294             } => {
 295                 crate::abi::codegen_terminator_call(fx, func, args, destination);
 296             }
 297             TerminatorKind::Resume | TerminatorKind::Abort | TerminatorKind::Unreachable => {
 298                 trap_unreachable(&mut fx.bcx);
 299             }
 300             TerminatorKind::Yield { .. }
 301             | TerminatorKind::FalseEdges { .. }
 302             | TerminatorKind::FalseUnwind { .. }
 303             | TerminatorKind::DropAndReplace { .. }
 304             | TerminatorKind::GeneratorDrop => {
 305                 bug!("shouldn't exist at trans {:?}", bb_data.terminator());
 306             }
 307             TerminatorKind::Drop {
 308                 location,
 309                 target,
 310                 unwind: _,
 311             } => {
 312                 let ty = location.ty(fx.mir, fx.tcx).to_ty(fx.tcx);
 313                 let ty = fx.monomorphize(&ty);
 314                 let drop_fn = crate::rustc_mir::monomorphize::resolve_drop_in_place(fx.tcx, ty);
 315
 316                 if let ty::InstanceDef::DropGlue(_, None) = drop_fn.def {
 317                     // we don't actually need to drop anything
 318                 } else {
 319                     let drop_place = trans_place(fx, location);
 320                     let drop_fn_ty = drop_fn.ty(fx.tcx);
 321                     match ty.sty {
 322                         ty::Dynamic(..) => {
 323                             crate::abi::codegen_drop(fx, drop_place, drop_fn_ty);
 324                         }
 325                         _ => {
 326                             let arg_place = CPlace::new_stack_slot(
 327                                 fx,
 328                                 fx.tcx.mk_ref(
 329                                     &ty::RegionKind::ReErased,
 330                                     TypeAndMut {
 331                                         ty,
 332                                         mutbl: crate::rustc::hir::Mutability::MutMutable,
 333                                     },
 334                                 ),
 335                             );
 336                             drop_place.write_place_ref(fx, arg_place);
 337                             let arg_value = arg_place.to_cvalue(fx);
 338                             crate::abi::codegen_call_inner(
 339                                 fx,
 340                                 None,
 341                                 drop_fn_ty,
 342                                 vec![arg_value],
 343                                 None,
 344                             );
 345                         }
 346                     }
 347                 }
 348
 349                 let target_ebb = fx.get_ebb(*target);
 350                 fx.bcx.ins().jump(target_ebb, &[]);
 351             }
 352         };
 353     }
 354
 355     fx.bcx.seal_all_blocks();
 356     fx.bcx.finalize();
 357 }
 358
 359 fn trans_stmt<'a, 'tcx: 'a>(
 360     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 361     cur_ebb: Ebb,
 362     stmt: &Statement<'tcx>,
 363 ) {
 364     let _print_guard = PrintOnPanic(|| format!("stmt {:?}", stmt));
 365
 366     fx.set_debug_loc(stmt.source_info);
 367
 368     #[cfg(debug_assertions)]
 369     match &stmt.kind {
 370         StatementKind::StorageLive(..) | StatementKind::StorageDead(..) => {} // Those are not very useful
 371         _ => {
 372             let inst = fx.bcx.func.layout.last_inst(cur_ebb).unwrap();
 373             fx.add_comment(inst, format!("{:?}", stmt));
 374         }
 375     }
 376
 377     match &stmt.kind {
 378         StatementKind::SetDiscriminant {
 379             place,
 380             variant_index,
 381         } => {
 382             let place = trans_place(fx, place);
 383             let layout = place.layout();
 384             if layout.for_variant(&*fx, *variant_index).abi == layout::Abi::Uninhabited {
 385                 return;
 386             }
 387             match layout.variants {
 388                 layout::Variants::Single { index } => {
 389                     assert_eq!(index, *variant_index);
 390                 }
 391                 layout::Variants::Tagged { .. } => {
 392                     let ptr = place.place_field(fx, mir::Field::new(0));
 393                     let to = layout
 394                         .ty
 395                         .ty_adt_def()
 396                         .unwrap()
 397                         .discriminant_for_variant(fx.tcx, *variant_index)
 398                         .val;
 399                     let discr = CValue::const_val(fx, ptr.layout().ty, to as u64 as i64);
 400                     ptr.write_cvalue(fx, discr);
 401                 }
 402                 layout::Variants::NicheFilling {
 403                     dataful_variant,
 404                     ref niche_variants,
 405                     niche_start,
 406                     ..
 407                 } => {
 408                     if *variant_index != dataful_variant {
 409                         let niche = place.place_field(fx, mir::Field::new(0));
 410                         //let niche_llty = niche.layout.immediate_llvm_type(bx.cx);
 411                         let niche_value =
 412                             ((variant_index.as_u32() - niche_variants.start().as_u32()) as u128)
 413                                 .wrapping_add(niche_start);
 414                         // FIXME(eddyb) Check the actual primitive type here.
 415                         let niche_llval = if niche_value == 0 {
 416                             CValue::const_val(fx, niche.layout().ty, 0)
 417                         } else {
 418                             CValue::const_val(fx, niche.layout().ty, niche_value as u64 as i64)
 419                         };
 420                         niche.write_cvalue(fx, niche_llval);
 421                     }
 422                 }
 423             }
 424         }
 425         StatementKind::Assign(to_place, rval) => {
 426             let lval = trans_place(fx, to_place);
 427             let dest_layout = lval.layout();
 428             match &**rval {
 429                 Rvalue::Use(operand) => {
 430                     let val = trans_operand(fx, operand);
 431                     lval.write_cvalue(fx, val);
 432                 }
 433                 Rvalue::Ref(_, _, place) => {
 434                     let place = trans_place(fx, place);
 435                     place.write_place_ref(fx, lval);
 436                 }
 437                 Rvalue::BinaryOp(bin_op, lhs, rhs) => {
 438                     let ty = fx.monomorphize(&lhs.ty(fx.mir, fx.tcx));
 439                     let lhs = trans_operand(fx, lhs);
 440                     let rhs = trans_operand(fx, rhs);
 441
 442                     let res = match ty.sty {
 443                         ty::Bool => trans_bool_binop(fx, *bin_op, lhs, rhs, lval.layout().ty),
 444                         ty::Uint(_) => {
 445                             trans_int_binop(fx, *bin_op, lhs, rhs, lval.layout().ty, false)
 446                         }
 447                         ty::Int(_) => {
 448                             trans_int_binop(fx, *bin_op, lhs, rhs, lval.layout().ty, true)
 449                         }
 450                         ty::Float(_) => trans_float_binop(fx, *bin_op, lhs, rhs, lval.layout().ty),
 451                         ty::Char => trans_char_binop(fx, *bin_op, lhs, rhs, lval.layout().ty),
 452                         ty::RawPtr(..) => trans_ptr_binop(fx, *bin_op, lhs, rhs, lval.layout().ty),
 453                         ty::FnPtr(..) => trans_ptr_binop(fx, *bin_op, lhs, rhs, lval.layout().ty),
 454                         _ => unimplemented!("binop {:?} for {:?}", bin_op, ty),
 455                     };
 456                     lval.write_cvalue(fx, res);
 457                 }
 458                 Rvalue::CheckedBinaryOp(bin_op, lhs, rhs) => {
 459                     let ty = fx.monomorphize(&lhs.ty(fx.mir, fx.tcx));
 460                     let lhs = trans_operand(fx, lhs);
 461                     let rhs = trans_operand(fx, rhs);
 462
 463                     let res = match ty.sty {
 464                         ty::Uint(_) => {
 465                             trans_checked_int_binop(fx, *bin_op, lhs, rhs, lval.layout().ty, false)
 466                         }
 467                         ty::Int(_) => {
 468                             trans_checked_int_binop(fx, *bin_op, lhs, rhs, lval.layout().ty, true)
 469                         }
 470                         _ => unimplemented!("checked binop {:?} for {:?}", bin_op, ty),
 471                     };
 472                     lval.write_cvalue(fx, res);
 473                 }
 474                 Rvalue::UnaryOp(un_op, operand) => {
 475                     let operand = trans_operand(fx, operand);
 476                     let layout = operand.layout();
 477                     let val = operand.load_scalar(fx);
 478                     let res = match un_op {
 479                         UnOp::Not => {
 480                             match layout.ty.sty {
 481                                 ty::Bool => {
 482                                     let val = fx.bcx.ins().uextend(types::I32, val); // WORKAROUND for CraneStation/cranelift#466
 483                                     let res = fx.bcx.ins().icmp_imm(IntCC::Equal, val, 0);
 484                                     fx.bcx.ins().bint(types::I8, res)
 485                                 }
 486                                 ty::Uint(_) | ty::Int(_) => fx.bcx.ins().bnot(val),
 487                                 _ => unimplemented!("un op Not for {:?}", layout.ty),
 488                             }
 489                         }
 490                         UnOp::Neg => match layout.ty.sty {
 491                             ty::Int(_) => {
 492                                 let clif_ty = fx.clif_type(layout.ty).unwrap();
 493                                 let zero = fx.bcx.ins().iconst(clif_ty, 0);
 494                                 fx.bcx.ins().isub(zero, val)
 495                             }
 496                             ty::Float(_) => fx.bcx.ins().fneg(val),
 497                             _ => unimplemented!("un op Neg for {:?}", layout.ty),
 498                         },
 499                     };
 500                     lval.write_cvalue(fx, CValue::ByVal(res, layout));
 501                 }
 502                 Rvalue::Cast(CastKind::ReifyFnPointer, operand, ty) => {
 503                     let layout = fx.layout_of(ty);
 504                     match fx
 505                         .monomorphize(&operand.ty(&fx.mir.local_decls, fx.tcx))
 506                         .sty
 507                     {
 508                         ty::FnDef(def_id, substs) => {
 509                             let func_ref = fx.get_function_ref(
 510                                 Instance::resolve(fx.tcx, ParamEnv::reveal_all(), def_id, substs)
 511                                     .unwrap(),
 512                             );
 513                             let func_addr = fx.bcx.ins().func_addr(fx.pointer_type, func_ref);
 514                             lval.write_cvalue(fx, CValue::ByVal(func_addr, layout));
 515                         }
 516                         _ => bug!("Trying to ReifyFnPointer on non FnDef {:?}", ty),
 517                     }
 518                 }
 519                 Rvalue::Cast(CastKind::UnsafeFnPointer, operand, ty)
 520                 | Rvalue::Cast(CastKind::MutToConstPointer, operand, ty) => {
 521                     let operand = trans_operand(fx, operand);
 522                     let layout = fx.layout_of(ty);
 523                     lval.write_cvalue(fx, operand.unchecked_cast_to(layout));
 524                 }
 525                 Rvalue::Cast(CastKind::Misc, operand, to_ty) => {
 526                     let operand = trans_operand(fx, operand);
 527                     let from_ty = operand.layout().ty;
 528
 529                     fn is_fat_ptr<'a, 'tcx: 'a>(fx: &FunctionCx<'a, 'tcx, impl Backend>, ty: Ty<'tcx>) -> bool {
 530                         ty
 531                             .builtin_deref(true)
 532                             .map(|ty::TypeAndMut {ty: pointee_ty, mutbl: _ }| fx.layout_of(pointee_ty).is_unsized())
 533                             .unwrap_or(false)
 534                     }
 535
 536                     if is_fat_ptr(fx, from_ty) {
 537                         if is_fat_ptr(fx, to_ty) {
 538                             // fat-ptr -> fat-ptr
 539                             lval.write_cvalue(fx, operand.unchecked_cast_to(dest_layout));
 540                         } else {
 541                             // fat-ptr -> thin-ptr
 542                             let (ptr, _extra) = operand.load_scalar_pair(fx);
 543                             lval.write_cvalue(fx, CValue::ByVal(ptr, dest_layout))
 544                         }
 545                     } else if let ty::Adt(adt_def, _substs) = from_ty.sty {
 546                         // enum -> discriminant value
 547                         assert!(adt_def.is_enum());
 548                         match to_ty.sty {
 549                             ty::Uint(_) | ty::Int(_) => {},
 550                             _ => unreachable!("cast adt {} -> {}", from_ty, to_ty),
 551                         }
 552
 553                         // FIXME avoid forcing to stack
 554                         let place =
 555                             CPlace::Addr(operand.force_stack(fx), None, operand.layout());
 556                         let discr = trans_get_discriminant(fx, place, fx.layout_of(to_ty));
 557                         lval.write_cvalue(fx, discr);
 558                     } else {
 559                         let from_clif_ty = fx.clif_type(from_ty).unwrap();
 560                         let to_clif_ty = fx.clif_type(to_ty).unwrap();
 561                         let from = operand.load_scalar(fx);
 562
 563                         let signed = match from_ty.sty {
 564                             ty::Ref(..) | ty::RawPtr(..) | ty::FnPtr(..) | ty::Char | ty::Uint(..) | ty::Bool => false,
 565                             ty::Int(..) => true,
 566                             ty::Float(..) => false, // `signed` is unused for floats
 567                             _ => panic!("{}", from_ty),
 568                         };
 569
 570                         let res = if from_clif_ty.is_int() && to_clif_ty.is_int() {
 571                             // int-like -> int-like
 572                             crate::common::clif_intcast(
 573                                 fx,
 574                                 from,
 575                                 to_clif_ty,
 576                                 signed,
 577                             )
 578                         } else if from_clif_ty.is_int() && to_clif_ty.is_float() {
 579                             // int-like -> float
 580                             // FIXME missing encoding for fcvt_from_sint.f32.i8
 581                             let from = if from_clif_ty == types::I8 || from_clif_ty == types::I16 {
 582                                 fx.bcx.ins().uextend(types::I32, from)
 583                             } else {
 584                                 from
 585                             };
 586                             if signed {
 587                                 fx.bcx.ins().fcvt_from_sint(to_clif_ty, from)
 588                             } else {
 589                                 fx.bcx.ins().fcvt_from_uint(to_clif_ty, from)
 590                             }
 591                         } else if from_clif_ty.is_float() && to_clif_ty.is_int() {
 592                             // float -> int-like
 593                             let from = operand.load_scalar(fx);
 594                             if signed {
 595                                 fx.bcx.ins().fcvt_to_sint_sat(to_clif_ty, from)
 596                             } else {
 597                                 fx.bcx.ins().fcvt_to_uint_sat(to_clif_ty, from)
 598                             }
 599                         } else if from_clif_ty.is_float() && to_clif_ty.is_float() {
 600                             // float -> float
 601                             match (from_clif_ty, to_clif_ty) {
 602                                 (types::F32, types::F64) => {
 603                                     fx.bcx.ins().fpromote(types::F64, from)
 604                                 }
 605                                 (types::F64, types::F32) => {
 606                                     fx.bcx.ins().fdemote(types::F32, from)
 607                                 }
 608                                 _ => from,
 609                             }
 610                         } else {
 611                             unimpl!("rval misc {:?} {:?}", from_ty, to_ty)
 612                         };
 613                         lval.write_cvalue(fx, CValue::ByVal(res, dest_layout));
 614                     }
 615                 }
 616                 Rvalue::Cast(CastKind::ClosureFnPointer, operand, _ty) => {
 617                     let operand = trans_operand(fx, operand);
 618                     match operand.layout().ty.sty {
 619                         ty::Closure(def_id, substs) => {
 620                             let instance = rustc_mir::monomorphize::resolve_closure(
 621                                 fx.tcx,
 622                                 def_id,
 623                                 substs,
 624                                 ty::ClosureKind::FnOnce,
 625                             );
 626                             let func_ref = fx.get_function_ref(instance);
 627                             let func_addr = fx.bcx.ins().func_addr(fx.pointer_type, func_ref);
 628                             lval.write_cvalue(fx, CValue::ByVal(func_addr, lval.layout()));
 629                         }
 630                         _ => {
 631                             bug!("{} cannot be cast to a fn ptr", operand.layout().ty)
 632                         }
 633                     }
 634                 }
 635                 Rvalue::Cast(CastKind::Unsize, operand, _ty) => {
 636                     let operand = trans_operand(fx, operand);
 637                     operand.unsize_value(fx, lval);
 638                 }
 639                 Rvalue::Discriminant(place) => {
 640                     let place = trans_place(fx, place);
 641                     let discr = trans_get_discriminant(fx, place, dest_layout);
 642                     lval.write_cvalue(fx, discr);
 643                 }
 644                 Rvalue::Repeat(operand, times) => {
 645                     let operand = trans_operand(fx, operand);
 646                     for i in 0..*times {
 647                         let index = fx.bcx.ins().iconst(fx.pointer_type, i as i64);
 648                         let to = lval.place_index(fx, index);
 649                         to.write_cvalue(fx, operand);
 650                     }
 651                 }
 652                 Rvalue::Len(place) => {
 653                     let place = trans_place(fx, place);
 654                     let usize_layout = fx.layout_of(fx.tcx.types.usize);
 655                     let len = codegen_array_len(fx, place);
 656                     lval.write_cvalue(fx, CValue::ByVal(len, usize_layout));
 657                 }
 658                 Rvalue::NullaryOp(NullOp::Box, content_ty) => {
 659                     use rustc::middle::lang_items::ExchangeMallocFnLangItem;
 660
 661                     let usize_type = fx.clif_type(fx.tcx.types.usize).unwrap();
 662                     let layout = fx.layout_of(content_ty);
 663                     let llsize = fx.bcx.ins().iconst(usize_type, layout.size.bytes() as i64);
 664                     let llalign = fx
 665                         .bcx
 666                         .ins()
 667                         .iconst(usize_type, layout.align.abi.bytes() as i64);
 668                     let box_layout = fx.layout_of(fx.tcx.mk_box(content_ty));
 669
 670                     // Allocate space:
 671                     let def_id = match fx.tcx.lang_items().require(ExchangeMallocFnLangItem) {
 672                         Ok(id) => id,
 673                         Err(s) => {
 674                             fx.tcx
 675                                 .sess
 676                                 .fatal(&format!("allocation of `{}` {}", box_layout.ty, s));
 677                         }
 678                     };
 679                     let instance = ty::Instance::mono(fx.tcx, def_id);
 680                     let func_ref = fx.get_function_ref(instance);
 681                     let call = fx.bcx.ins().call(func_ref, &[llsize, llalign]);
 682                     let ptr = fx.bcx.inst_results(call)[0];
 683                     lval.write_cvalue(fx, CValue::ByVal(ptr, box_layout));
 684                 }
 685                 Rvalue::NullaryOp(NullOp::SizeOf, ty) => {
 686                     assert!(lval
 687                         .layout()
 688                         .ty
 689                         .is_sized(fx.tcx.at(DUMMY_SP), ParamEnv::reveal_all()));
 690                     let ty_size = fx.layout_of(ty).size.bytes();
 691                     let val = CValue::const_val(fx, fx.tcx.types.usize, ty_size as i64);
 692                     lval.write_cvalue(fx, val);
 693                 }
 694                 Rvalue::Aggregate(kind, operands) => match **kind {
 695                     AggregateKind::Array(_ty) => {
 696                         for (i, operand) in operands.into_iter().enumerate() {
 697                             let operand = trans_operand(fx, operand);
 698                             let index = fx.bcx.ins().iconst(fx.pointer_type, i as i64);
 699                             let to = lval.place_index(fx, index);
 700                             to.write_cvalue(fx, operand);
 701                         }
 702                     }
 703                     _ => unimpl!("shouldn't exist at trans {:?}", rval),
 704                 },
 705             }
 706         }
 707         StatementKind::StorageLive(_)
 708         | StatementKind::StorageDead(_)
 709         | StatementKind::Nop
 710         | StatementKind::FakeRead(..)
 711         | StatementKind::Retag { .. }
 712         | StatementKind::AscribeUserType(..) => {}
 713
 714         StatementKind::InlineAsm { .. } => unimpl!("Inline assembly is not supported"),
 715     }
 716 }
 717
 718 fn codegen_array_len<'a, 'tcx: 'a>(
 719     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 720     place: CPlace<'tcx>,
 721 ) -> Value {
 722     match place.layout().ty.sty {
 723         ty::Array(_elem_ty, len) => {
 724             let len = crate::constant::force_eval_const(fx, len).unwrap_usize(fx.tcx) as i64;
 725             fx.bcx.ins().iconst(fx.pointer_type, len)
 726         }
 727         ty::Slice(_elem_ty) => place
 728             .to_addr_maybe_unsized(fx)
 729             .1
 730             .expect("Length metadata for slice place"),
 731         _ => bug!("Rvalue::Len({:?})", place),
 732     }
 733 }
 734
 735 pub fn trans_get_discriminant<'a, 'tcx: 'a>(
 736     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 737     place: CPlace<'tcx>,
 738     dest_layout: TyLayout<'tcx>,
 739 ) -> CValue<'tcx> {
 740     let layout = place.layout();
 741
 742     if layout.abi == layout::Abi::Uninhabited {
 743         return trap_unreachable_ret_value(fx, dest_layout);
 744     }
 745     match layout.variants {
 746         layout::Variants::Single { index } => {
 747             let discr_val = layout
 748                 .ty
 749                 .ty_adt_def()
 750                 .map_or(index.as_u32() as u128, |def| {
 751                     def.discriminant_for_variant(fx.tcx, index).val
 752                 });
 753             return CValue::const_val(fx, dest_layout.ty, discr_val as u64 as i64);
 754         }
 755         layout::Variants::Tagged { .. } | layout::Variants::NicheFilling { .. } => {}
 756     }
 757
 758     let discr = place.place_field(fx, mir::Field::new(0)).to_cvalue(fx);
 759     let discr_ty = discr.layout().ty;
 760     let lldiscr = discr.load_scalar(fx);
 761     match layout.variants {
 762         layout::Variants::Single { .. } => bug!(),
 763         layout::Variants::Tagged { ref tag, .. } => {
 764             let signed = match tag.value {
 765                 layout::Int(_, signed) => signed,
 766                 _ => false,
 767             };
 768             let val = clif_intcast(fx, lldiscr, fx.clif_type(dest_layout.ty).unwrap(), signed);
 769             return CValue::ByVal(val, dest_layout);
 770         }
 771         layout::Variants::NicheFilling {
 772             dataful_variant,
 773             ref niche_variants,
 774             niche_start,
 775             ..
 776         } => {
 777             let niche_llty = fx.clif_type(discr_ty).unwrap();
 778             let dest_clif_ty = fx.clif_type(dest_layout.ty).unwrap();
 779             if niche_variants.start() == niche_variants.end() {
 780                 let b = fx
 781                     .bcx
 782                     .ins()
 783                     .icmp_imm(IntCC::Equal, lldiscr, niche_start as u64 as i64);
 784                 let if_true = fx
 785                     .bcx
 786                     .ins()
 787                     .iconst(dest_clif_ty, niche_variants.start().as_u32() as i64);
 788                 let if_false = fx
 789                     .bcx
 790                     .ins()
 791                     .iconst(dest_clif_ty, dataful_variant.as_u32() as i64);
 792                 let val = fx.bcx.ins().select(b, if_true, if_false);
 793                 return CValue::ByVal(val, dest_layout);
 794             } else {
 795                 // Rebase from niche values to discriminant values.
 796                 let delta = niche_start.wrapping_sub(niche_variants.start().as_u32() as u128);
 797                 let delta = fx.bcx.ins().iconst(niche_llty, delta as u64 as i64);
 798                 let lldiscr = fx.bcx.ins().isub(lldiscr, delta);
 799                 let b = fx.bcx.ins().icmp_imm(
 800                     IntCC::UnsignedLessThanOrEqual,
 801                     lldiscr,
 802                     niche_variants.end().as_u32() as i64,
 803                 );
 804                 let if_true =
 805                     clif_intcast(fx, lldiscr, fx.clif_type(dest_layout.ty).unwrap(), false);
 806                 let if_false = fx
 807                     .bcx
 808                     .ins()
 809                     .iconst(dest_clif_ty, dataful_variant.as_u32() as i64);
 810                 let val = fx.bcx.ins().select(b, if_true, if_false);
 811                 return CValue::ByVal(val, dest_layout);
 812             }
 813         }
 814     }
 815 }
 816
 817 macro_rules! binop_match {
 818     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, bug) => {
 819         bug!("binop {} on {} lhs: {:?} rhs: {:?}", stringify!($var), $bug_fmt, $lhs, $rhs)
 820     };
 821     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, icmp($cc:ident)) => {{
 822         assert_eq!($fx.tcx.types.bool, $ret_ty);
 823         let ret_layout = $fx.layout_of($ret_ty);
 824
 825         let b = $fx.bcx.ins().icmp(IntCC::$cc, $lhs, $rhs);
 826         CValue::ByVal($fx.bcx.ins().bint(types::I8, b), ret_layout)
 827     }};
 828     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, fcmp($cc:ident)) => {{
 829         assert_eq!($fx.tcx.types.bool, $ret_ty);
 830         let ret_layout = $fx.layout_of($ret_ty);
 831         let b = $fx.bcx.ins().fcmp(FloatCC::$cc, $lhs, $rhs);
 832         CValue::ByVal($fx.bcx.ins().bint(types::I8, b), ret_layout)
 833     }};
 834     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, custom(|| $body:expr)) => {{
 835         $body
 836     }};
 837     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, $name:ident) => {{
 838         let ret_layout = $fx.layout_of($ret_ty);
 839         CValue::ByVal($fx.bcx.ins().$name($lhs, $rhs), ret_layout)
 840     }};
 841     (
 842         $fx:expr, $bin_op:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, $bug_fmt:expr;
 843         $(
 844             $var:ident ($sign:pat) $name:tt $( ( $($next:tt)* ) )? ;
 845         )*
 846     ) => {{
 847         let lhs = $lhs.load_scalar($fx);
 848         let rhs = $rhs.load_scalar($fx);
 849         match ($bin_op, $signed) {
 850             $(
 851                 (BinOp::$var, $sign) => binop_match!(@single $fx, $bug_fmt, $var, $signed, lhs, rhs, $ret_ty, $name $( ( $($next)* ) )?),
 852             )*
 853         }
 854     }}
 855 }
 856
 857 fn trans_bool_binop<'a, 'tcx: 'a>(
 858     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 859     bin_op: BinOp,
 860     lhs: CValue<'tcx>,
 861     rhs: CValue<'tcx>,
 862     ty: Ty<'tcx>,
 863 ) -> CValue<'tcx> {
 864     let res = binop_match! {
 865         fx, bin_op, false, lhs, rhs, ty, "bool";
 866         Add (_) bug;
 867         Sub (_) bug;
 868         Mul (_) bug;
 869         Div (_) bug;
 870         Rem (_) bug;
 871         BitXor (_) bxor;
 872         BitAnd (_) band;
 873         BitOr (_) bor;
 874         Shl (_) bug;
 875         Shr (_) bug;
 876
 877         Eq (_) icmp(Equal);
 878         Lt (_) icmp(UnsignedLessThan);
 879         Le (_) icmp(UnsignedLessThanOrEqual);
 880         Ne (_) icmp(NotEqual);
 881         Ge (_) icmp(UnsignedGreaterThanOrEqual);
 882         Gt (_) icmp(UnsignedGreaterThan);
 883
 884         Offset (_) bug;
 885     };
 886
 887     res
 888 }
 889
 890 pub fn trans_int_binop<'a, 'tcx: 'a>(
 891     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 892     bin_op: BinOp,
 893     lhs: CValue<'tcx>,
 894     rhs: CValue<'tcx>,
 895     out_ty: Ty<'tcx>,
 896     signed: bool,
 897 ) -> CValue<'tcx> {
 898     if bin_op != BinOp::Shl && bin_op != BinOp::Shr {
 899         assert_eq!(
 900             lhs.layout().ty,
 901             rhs.layout().ty,
 902             "int binop requires lhs and rhs of same type"
 903         );
 904     }
 905     binop_match! {
 906         fx, bin_op, signed, lhs, rhs, out_ty, "int/uint";
 907         Add (_) iadd;
 908         Sub (_) isub;
 909         Mul (_) imul;
 910         Div (false) udiv;
 911         Div (true) sdiv;
 912         Rem (false) urem;
 913         Rem (true) srem;
 914         BitXor (_) bxor;
 915         BitAnd (_) band;
 916         BitOr (_) bor;
 917         Shl (_) ishl;
 918         Shr (false) ushr;
 919         Shr (true) sshr;
 920
 921         Eq (_) icmp(Equal);
 922         Lt (false) icmp(UnsignedLessThan);
 923         Lt (true) icmp(SignedLessThan);
 924         Le (false) icmp(UnsignedLessThanOrEqual);
 925         Le (true) icmp(SignedLessThanOrEqual);
 926         Ne (_) icmp(NotEqual);
 927         Ge (false) icmp(UnsignedGreaterThanOrEqual);
 928         Ge (true) icmp(SignedGreaterThanOrEqual);
 929         Gt (false) icmp(UnsignedGreaterThan);
 930         Gt (true) icmp(SignedGreaterThan);
 931
 932         Offset (_) bug;
 933     }
 934 }
 935
 936 pub fn trans_checked_int_binop<'a, 'tcx: 'a>(
 937     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 938     bin_op: BinOp,
 939     in_lhs: CValue<'tcx>,
 940     in_rhs: CValue<'tcx>,
 941     out_ty: Ty<'tcx>,
 942     signed: bool,
 943 ) -> CValue<'tcx> {
 944     if bin_op != BinOp::Shl && bin_op != BinOp::Shr {
 945         assert_eq!(
 946             in_lhs.layout().ty,
 947             in_rhs.layout().ty,
 948             "checked int binop requires lhs and rhs of same type"
 949         );
 950     }
 951
 952     let lhs = in_lhs.load_scalar(fx);
 953     let rhs = in_rhs.load_scalar(fx);
 954     let res = match bin_op {
 955         BinOp::Add => fx.bcx.ins().iadd(lhs, rhs),
 956         BinOp::Sub => fx.bcx.ins().isub(lhs, rhs),
 957         BinOp::Mul => fx.bcx.ins().imul(lhs, rhs),
 958         BinOp::Shl => fx.bcx.ins().ishl(lhs, rhs),
 959         BinOp::Shr => {
 960             if !signed {
 961                 fx.bcx.ins().ushr(lhs, rhs)
 962             } else {
 963                 fx.bcx.ins().sshr(lhs, rhs)
 964             }
 965         }
 966         _ => bug!(
 967             "binop {:?} on checked int/uint lhs: {:?} rhs: {:?}",
 968             bin_op,
 969             in_lhs,
 970             in_rhs
 971         ),
 972     };
 973
 974     // TODO: check for overflow
 975     let has_overflow = fx.bcx.ins().iconst(types::I8, 0);
 976
 977     let out_place = CPlace::new_stack_slot(fx, out_ty);
 978     let out_layout = out_place.layout();
 979     out_place.write_cvalue(fx, CValue::ByValPair(res, has_overflow, out_layout));
 980
 981     out_place.to_cvalue(fx)
 982 }
 983
 984 fn trans_float_binop<'a, 'tcx: 'a>(
 985     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 986     bin_op: BinOp,
 987     lhs: CValue<'tcx>,
 988     rhs: CValue<'tcx>,
 989     ty: Ty<'tcx>,
 990 ) -> CValue<'tcx> {
 991     let res = binop_match! {
 992         fx, bin_op, false, lhs, rhs, ty, "float";
 993         Add (_) fadd;
 994         Sub (_) fsub;
 995         Mul (_) fmul;
 996         Div (_) fdiv;
 997         Rem (_) custom(|| {
 998             assert_eq!(lhs.layout().ty, ty);
 999             assert_eq!(rhs.layout().ty, ty);
1000             match ty.sty {
1001                 ty::Float(FloatTy::F32) => fx.easy_call("fmodf", &[lhs, rhs], ty),
1002                 ty::Float(FloatTy::F64) => fx.easy_call("fmod", &[lhs, rhs], ty),
1003                 _ => bug!(),
1004             }
1005         });
1006         BitXor (_) bxor;
1007         BitAnd (_) band;
1008         BitOr (_) bor;
1009         Shl (_) bug;
1010         Shr (_) bug;
1011
1012         Eq (_) fcmp(Equal);
1013         Lt (_) fcmp(LessThan);
1014         Le (_) fcmp(LessThanOrEqual);
1015         Ne (_) fcmp(NotEqual);
1016         Ge (_) fcmp(GreaterThanOrEqual);
1017         Gt (_) fcmp(GreaterThan);
1018
1019         Offset (_) bug;
1020     };
1021
1022     res
1023 }
1024
1025 fn trans_char_binop<'a, 'tcx: 'a>(
1026     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
1027     bin_op: BinOp,
1028     lhs: CValue<'tcx>,
1029     rhs: CValue<'tcx>,
1030     ty: Ty<'tcx>,
1031 ) -> CValue<'tcx> {
1032     let res = binop_match! {
1033         fx, bin_op, false, lhs, rhs, ty, "char";
1034         Add (_) bug;
1035         Sub (_) bug;
1036         Mul (_) bug;
1037         Div (_) bug;
1038         Rem (_) bug;
1039         BitXor (_) bug;
1040         BitAnd (_) bug;
1041         BitOr (_) bug;
1042         Shl (_) bug;
1043         Shr (_) bug;
1044
1045         Eq (_) icmp(Equal);
1046         Lt (_) icmp(UnsignedLessThan);
1047         Le (_) icmp(UnsignedLessThanOrEqual);
1048         Ne (_) icmp(NotEqual);
1049         Ge (_) icmp(UnsignedGreaterThanOrEqual);
1050         Gt (_) icmp(UnsignedGreaterThan);
1051
1052         Offset (_) bug;
1053     };
1054
1055     res
1056 }
1057
1058 fn trans_ptr_binop<'a, 'tcx: 'a>(
1059     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
1060     bin_op: BinOp,
1061     lhs: CValue<'tcx>,
1062     rhs: CValue<'tcx>,
1063     ret_ty: Ty<'tcx>,
1064 ) -> CValue<'tcx> {
1065     let not_fat = match lhs.layout().ty.sty {
1066         ty::RawPtr(TypeAndMut { ty, mutbl: _ }) => {
1067             ty.is_sized(fx.tcx.at(DUMMY_SP), ParamEnv::reveal_all())
1068         }
1069         ty::FnPtr(..) => true,
1070         _ => bug!("trans_ptr_binop on non ptr"),
1071     };
1072     if not_fat {
1073         if let BinOp::Offset = bin_op {
1074             let (base, offset) = (lhs, rhs.load_scalar(fx));
1075             let pointee_ty = base.layout().ty.builtin_deref(true).unwrap().ty;
1076             let pointee_size = fx.layout_of(pointee_ty).size.bytes();
1077             let ptr_diff = fx.bcx.ins().imul_imm(offset, pointee_size as i64);
1078             let base_val = base.load_scalar(fx);
1079             let res = fx.bcx.ins().iadd(base_val, ptr_diff);
1080             return CValue::ByVal(res, base.layout());
1081         }
1082
1083         binop_match! {
1084             fx, bin_op, false, lhs, rhs, ret_ty, "ptr";
1085             Add (_) bug;
1086             Sub (_) bug;
1087             Mul (_) bug;
1088             Div (_) bug;
1089             Rem (_) bug;
1090             BitXor (_) bug;
1091             BitAnd (_) bug;
1092             BitOr (_) bug;
1093             Shl (_) bug;
1094             Shr (_) bug;
1095
1096             Eq (_) icmp(Equal);
1097             Lt (_) icmp(UnsignedLessThan);
1098             Le (_) icmp(UnsignedLessThanOrEqual);
1099             Ne (_) icmp(NotEqual);
1100             Ge (_) icmp(UnsignedGreaterThanOrEqual);
1101             Gt (_) icmp(UnsignedGreaterThan);
1102
1103             Offset (_) bug; // Handled above
1104         }
1105     } else {
1106         let (lhs_ptr, lhs_extra) = lhs.load_scalar_pair(fx);
1107         let (rhs_ptr, rhs_extra) = rhs.load_scalar_pair(fx);
1108         let res = match bin_op {
1109             BinOp::Eq => {
1110                 let ptr_eq = fx.bcx.ins().icmp(IntCC::Equal, lhs_ptr, rhs_ptr);
1111                 let extra_eq = fx.bcx.ins().icmp(IntCC::Equal, lhs_extra, rhs_extra);
1112                 fx.bcx.ins().band(ptr_eq, extra_eq)
1113             }
1114             BinOp::Ne => {
1115                 let ptr_ne = fx.bcx.ins().icmp(IntCC::NotEqual, lhs_ptr, rhs_ptr);
1116                 let extra_ne = fx.bcx.ins().icmp(IntCC::NotEqual, lhs_extra, rhs_extra);
1117                 fx.bcx.ins().bor(ptr_ne, extra_ne)
1118             }
1119             _ => unimplemented!(
1120                 "trans_ptr_binop({:?}, <fat ptr>, <fat ptr>) not implemented",
1121                 bin_op
1122             ),
1123         };
1124
1125         assert_eq!(fx.tcx.types.bool, ret_ty);
1126         let ret_layout = fx.layout_of(ret_ty);
1127         CValue::ByVal(fx.bcx.ins().bint(types::I8, res), ret_layout)
1128     }
1129 }
1130
1131 pub fn trans_place<'a, 'tcx: 'a>(
1132     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
1133     place: &Place<'tcx>,
1134 ) -> CPlace<'tcx> {
1135     match place {
1136         Place::Base(base) => match base {
1137             PlaceBase::Local(local) => fx.get_local_place(*local),
1138             PlaceBase::Promoted(data) => crate::constant::trans_promoted(fx, data.0, data.1),
1139             PlaceBase::Static(static_) => crate::constant::codegen_static_ref(fx, static_),
1140         }
1141         Place::Projection(projection) => {
1142             let base = trans_place(fx, &projection.base);
1143             match projection.elem {
1144                 ProjectionElem::Deref => base.place_deref(fx),
1145                 ProjectionElem::Field(field, _ty) => base.place_field(fx, field),
1146                 ProjectionElem::Index(local) => {
1147                     let index = fx.get_local_place(local).to_cvalue(fx).load_scalar(fx);
1148                     base.place_index(fx, index)
1149                 }
1150                 ProjectionElem::ConstantIndex {
1151                     offset,
1152                     min_length: _,
1153                     from_end,
1154                 } => {
1155                     let index = if !from_end {
1156                         fx.bcx.ins().iconst(fx.pointer_type, offset as i64)
1157                     } else {
1158                         let len = codegen_array_len(fx, base);
1159                         fx.bcx.ins().iadd_imm(len, -(offset as i64))
1160                     };
1161                     base.place_index(fx, index)
1162                 }
1163                 ProjectionElem::Subslice { from, to } => {
1164                     // These indices are generated by slice patterns.
1165                     // slice[from:-to] in Python terms.
1166
1167                     match base.layout().ty.sty {
1168                         ty::Array(elem_ty, len) => {
1169                             let elem_layout = fx.layout_of(elem_ty);
1170                             let ptr = base.to_addr(fx);
1171                             let len = crate::constant::force_eval_const(fx, len).unwrap_usize(fx.tcx);
1172                             CPlace::Addr(
1173                                 fx.bcx.ins().iadd_imm(ptr, elem_layout.size.bytes() as i64 * from as i64),
1174                                 None,
1175                                 fx.layout_of(fx.tcx.mk_array(elem_ty, len - from as u64 - to as u64)),
1176                             )
1177                         }
1178                         ty::Slice(elem_ty) => {
1179                             let elem_layout = fx.layout_of(elem_ty);
1180                             let (ptr, len) = base.to_addr_maybe_unsized(fx);
1181                             let len = len.unwrap();
1182                             CPlace::Addr(
1183                                 fx.bcx.ins().iadd_imm(ptr, elem_layout.size.bytes() as i64 * from as i64),
1184                                 Some(fx.bcx.ins().iadd_imm(len, -(from as i64 + to as i64))),
1185                                 base.layout(),
1186                             )
1187                         }
1188                         _ => unreachable!(),
1189                     }
1190                 }
1191                 ProjectionElem::Downcast(_adt_def, variant) => base.downcast_variant(fx, variant),
1192             }
1193         }
1194     }
1195 }
1196
1197 pub fn trans_operand<'a, 'tcx>(
1198     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
1199     operand: &Operand<'tcx>,
1200 ) -> CValue<'tcx> {
1201     match operand {
1202         Operand::Move(place) | Operand::Copy(place) => {
1203             let cplace = trans_place(fx, place);
1204             cplace.to_cvalue(fx)
1205         }
1206         Operand::Constant(const_) => crate::constant::trans_constant(fx, const_),
1207     }
1208 }