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
 112             let mut fx = FunctionCx {
 113                 tcx,
 114                 module: cx.module,
 115                 pointer_type: pointer_ty(tcx),
 116
 117                 instance,
 118                 mir,
 119
 120                 bcx,
 121                 ebb_map: HashMap::new(),
 122                 local_map: HashMap::new(),
 123
 124                 clif_comments: crate::pretty_clif::CommentWriter::new(tcx, instance),
 125                 constants: &mut cx.ccx,
 126                 caches: &mut cx.caches,
 127                 source_info_set: indexmap::IndexSet::new(),
 128             };
 129
 130             crate::trap::trap_unreachable(&mut fx, "[unimplemented] Called function with u128 or i128 as argument.");
 131             fx.bcx.seal_all_blocks();
 132             fx.bcx.finalize();
 133
 134             // Step 2b3. Define function
 135             cx.caches.context.func = func;
 136             cx.module
 137                 .define_function(func_id, &mut cx.caches.context)
 138                 .unwrap();
 139             cx.caches.context.clear();
 140             return;
 141         }
 142     }
 143
 144     // Step 3. Declare function
 145     let (name, sig) = get_function_name_and_sig(tcx, instance, false);
 146     let func_id = cx.module.declare_function(&name, linkage, &sig).unwrap();
 147     let mut debug_context = cx
 148         .debug_context
 149         .as_mut()
 150         .map(|debug_context| FunctionDebugContext::new(tcx, debug_context, mir, &name, &sig));
 151
 152     // Step 4. Make FunctionBuilder
 153     let mut func = Function::with_name_signature(ExternalName::user(0, 0), sig);
 154     let mut func_ctx = FunctionBuilderContext::new();
 155     let mut bcx = FunctionBuilder::new(&mut func, &mut func_ctx);
 156
 157     // Step 5. Predefine ebb's
 158     let start_ebb = bcx.create_ebb();
 159     let mut ebb_map: HashMap<BasicBlock, Ebb> = HashMap::new();
 160     for (bb, _bb_data) in mir.basic_blocks().iter_enumerated() {
 161         ebb_map.insert(bb, bcx.create_ebb());
 162     }
 163
 164     // Step 6. Make FunctionCx
 165     let pointer_type = cx.module.target_config().pointer_type();
 166     let clif_comments = crate::pretty_clif::CommentWriter::new(tcx, instance);
 167
 168     let mut fx = FunctionCx {
 169         tcx,
 170         module: cx.module,
 171         pointer_type,
 172
 173         instance,
 174         mir,
 175
 176         bcx,
 177         ebb_map,
 178         local_map: HashMap::new(),
 179
 180         clif_comments,
 181         constants: &mut cx.ccx,
 182         caches: &mut cx.caches,
 183         source_info_set: indexmap::IndexSet::new(),
 184     };
 185
 186     // Step 7. Codegen function
 187     with_unimpl_span(fx.mir.span, || {
 188         crate::abi::codegen_fn_prelude(&mut fx, start_ebb);
 189         codegen_fn_content(&mut fx);
 190     });
 191     let source_info_set = fx.source_info_set.clone();
 192
 193     // Step 8. Write function to file for debugging
 194     #[cfg(debug_assertions)]
 195     fx.write_clif_file();
 196
 197     // Step 9. Verify function
 198     verify_func(tcx, fx.clif_comments, &func);
 199
 200     // Step 10. Define function
 201     cx.caches.context.func = func;
 202     cx.module
 203         .define_function(func_id, &mut cx.caches.context)
 204         .unwrap();
 205
 206     // Step 11. Define debuginfo for function
 207     let context = &cx.caches.context;
 208     let isa = cx.module.isa();
 209     debug_context
 210         .as_mut()
 211         .map(|x| x.define(tcx, context, isa, &source_info_set));
 212
 213     // Step 12. Clear context to make it usable for the next function
 214     cx.caches.context.clear();
 215 }
 216
 217 fn verify_func(tcx: TyCtxt, writer: crate::pretty_clif::CommentWriter, func: &Function) {
 218     let flags = settings::Flags::new(settings::builder());
 219     match ::cranelift::codegen::verify_function(&func, &flags) {
 220         Ok(_) => {}
 221         Err(err) => {
 222             tcx.sess.err(&format!("{:?}", err));
 223             let pretty_error = ::cranelift::codegen::print_errors::pretty_verifier_error(
 224                 &func,
 225                 None,
 226                 Some(Box::new(&writer)),
 227                 err,
 228             );
 229             tcx.sess
 230                 .fatal(&format!("cranelift verify error:\n{}", pretty_error));
 231         }
 232     }
 233 }
 234
 235 fn codegen_fn_content<'a, 'tcx: 'a>(fx: &mut FunctionCx<'a, 'tcx, impl Backend>) {
 236     for (bb, bb_data) in fx.mir.basic_blocks().iter_enumerated() {
 237         if bb_data.is_cleanup {
 238             // Unwinding after panicking is not supported
 239             continue;
 240         }
 241
 242         let ebb = fx.get_ebb(bb);
 243         fx.bcx.switch_to_block(ebb);
 244
 245         fx.bcx.ins().nop();
 246         for stmt in &bb_data.statements {
 247             fx.set_debug_loc(stmt.source_info);
 248             trans_stmt(fx, ebb, stmt);
 249         }
 250
 251         #[cfg(debug_assertions)]
 252         {
 253             let mut terminator_head = "\n".to_string();
 254             bb_data
 255                 .terminator()
 256                 .kind
 257                 .fmt_head(&mut terminator_head)
 258                 .unwrap();
 259             let inst = fx.bcx.func.layout.last_inst(ebb).unwrap();
 260             fx.add_comment(inst, terminator_head);
 261         }
 262
 263         fx.set_debug_loc(bb_data.terminator().source_info);
 264
 265         match &bb_data.terminator().kind {
 266             TerminatorKind::Goto { target } => {
 267                 let ebb = fx.get_ebb(*target);
 268                 fx.bcx.ins().jump(ebb, &[]);
 269             }
 270             TerminatorKind::Return => {
 271                 crate::abi::codegen_return(fx);
 272             }
 273             TerminatorKind::Assert {
 274                 cond,
 275                 expected,
 276                 msg,
 277                 target,
 278                 cleanup: _,
 279             } => {
 280                 let cond = trans_operand(fx, cond).load_scalar(fx);
 281                 // TODO HACK brz/brnz for i8/i16 is not yet implemented
 282                 let cond = fx.bcx.ins().uextend(types::I32, cond);
 283                 let target = fx.get_ebb(*target);
 284                 if *expected {
 285                     fx.bcx.ins().brnz(cond, target, &[]);
 286                 } else {
 287                     fx.bcx.ins().brz(cond, target, &[]);
 288                 };
 289                 trap_panic(fx, format!("[panic] Assert {:?} failed.", msg));
 290             }
 291
 292             TerminatorKind::SwitchInt {
 293                 discr,
 294                 switch_ty: _,
 295                 values,
 296                 targets,
 297             } => {
 298                 let discr = trans_operand(fx, discr).load_scalar(fx);
 299                 let mut switch = ::cranelift::frontend::Switch::new();
 300                 for (i, value) in values.iter().enumerate() {
 301                     let ebb = fx.get_ebb(targets[i]);
 302                     switch.set_entry(*value as u64, ebb);
 303                 }
 304                 let otherwise_ebb = fx.get_ebb(targets[targets.len() - 1]);
 305                 switch.emit(&mut fx.bcx, discr, otherwise_ebb);
 306             }
 307             TerminatorKind::Call {
 308                 func,
 309                 args,
 310                 destination,
 311                 cleanup: _,
 312                 from_hir_call: _,
 313             } => {
 314                 crate::abi::codegen_terminator_call(fx, func, args, destination);
 315             }
 316             TerminatorKind::Resume | TerminatorKind::Abort => {
 317                 trap_unreachable(fx, "[corruption] Unwinding bb reached.");
 318             }
 319             TerminatorKind::Unreachable => {
 320                 trap_unreachable(fx, "[corruption] Hit unreachable code.");
 321             }
 322             TerminatorKind::Yield { .. }
 323             | TerminatorKind::FalseEdges { .. }
 324             | TerminatorKind::FalseUnwind { .. }
 325             | TerminatorKind::DropAndReplace { .. }
 326             | TerminatorKind::GeneratorDrop => {
 327                 bug!("shouldn't exist at trans {:?}", bb_data.terminator());
 328             }
 329             TerminatorKind::Drop {
 330                 location,
 331                 target,
 332                 unwind: _,
 333             } => {
 334                 let ty = location.ty(fx.mir, fx.tcx).ty;
 335                 let ty = fx.monomorphize(&ty);
 336                 let drop_fn = crate::rustc_mir::monomorphize::resolve_drop_in_place(fx.tcx, ty);
 337
 338                 if let ty::InstanceDef::DropGlue(_, None) = drop_fn.def {
 339                     // we don't actually need to drop anything
 340                 } else {
 341                     let drop_place = trans_place(fx, location);
 342                     let drop_fn_ty = drop_fn.ty(fx.tcx);
 343                     match ty.sty {
 344                         ty::Dynamic(..) => {
 345                             crate::abi::codegen_drop(fx, drop_place, drop_fn_ty);
 346                         }
 347                         _ => {
 348                             let arg_place = CPlace::new_stack_slot(
 349                                 fx,
 350                                 fx.tcx.mk_ref(
 351                                     &ty::RegionKind::ReErased,
 352                                     TypeAndMut {
 353                                         ty,
 354                                         mutbl: crate::rustc::hir::Mutability::MutMutable,
 355                                     },
 356                                 ),
 357                             );
 358                             drop_place.write_place_ref(fx, arg_place);
 359                             let arg_value = arg_place.to_cvalue(fx);
 360                             crate::abi::codegen_call_inner(
 361                                 fx,
 362                                 None,
 363                                 drop_fn_ty,
 364                                 vec![arg_value],
 365                                 None,
 366                             );
 367                         }
 368                     }
 369                 }
 370
 371                 let target_ebb = fx.get_ebb(*target);
 372                 fx.bcx.ins().jump(target_ebb, &[]);
 373             }
 374         };
 375     }
 376
 377     fx.bcx.seal_all_blocks();
 378     fx.bcx.finalize();
 379 }
 380
 381 fn trans_stmt<'a, 'tcx: 'a>(
 382     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 383     cur_ebb: Ebb,
 384     stmt: &Statement<'tcx>,
 385 ) {
 386     let _print_guard = PrintOnPanic(|| format!("stmt {:?}", stmt));
 387
 388     fx.set_debug_loc(stmt.source_info);
 389
 390     #[cfg(debug_assertions)]
 391     match &stmt.kind {
 392         StatementKind::StorageLive(..) | StatementKind::StorageDead(..) => {} // Those are not very useful
 393         _ => {
 394             let inst = fx.bcx.func.layout.last_inst(cur_ebb).unwrap();
 395             fx.add_comment(inst, format!("{:?}", stmt));
 396         }
 397     }
 398
 399     match &stmt.kind {
 400         StatementKind::SetDiscriminant {
 401             place,
 402             variant_index,
 403         } => {
 404             let place = trans_place(fx, place);
 405             let layout = place.layout();
 406             if layout.for_variant(&*fx, *variant_index).abi == layout::Abi::Uninhabited {
 407                 return;
 408             }
 409             match layout.variants {
 410                 layout::Variants::Single { index } => {
 411                     assert_eq!(index, *variant_index);
 412                 }
 413                 layout::Variants::Multiple { discr_kind: layout::DiscriminantKind::Tag, .. } => {
 414                     let ptr = place.place_field(fx, mir::Field::new(0));
 415                     let to = layout
 416                         .ty
 417                         .ty_adt_def()
 418                         .unwrap()
 419                         .discriminant_for_variant(fx.tcx, *variant_index)
 420                         .val;
 421                     let discr = CValue::const_val(fx, ptr.layout().ty, to as u64 as i64);
 422                     ptr.write_cvalue(fx, discr);
 423                 }
 424                 layout::Variants::Multiple {
 425                     discr_kind: layout::DiscriminantKind::Niche {
 426                         dataful_variant,
 427                         ref niche_variants,
 428                         niche_start,
 429                     },
 430                     ..
 431                 } => {
 432                     if *variant_index != dataful_variant {
 433                         let niche = place.place_field(fx, mir::Field::new(0));
 434                         //let niche_llty = niche.layout.immediate_llvm_type(bx.cx);
 435                         let niche_value =
 436                             ((variant_index.as_u32() - niche_variants.start().as_u32()) as u128)
 437                                 .wrapping_add(niche_start);
 438                         // FIXME(eddyb) Check the actual primitive type here.
 439                         let niche_llval = if niche_value == 0 {
 440                             CValue::const_val(fx, niche.layout().ty, 0)
 441                         } else {
 442                             CValue::const_val(fx, niche.layout().ty, niche_value as u64 as i64)
 443                         };
 444                         niche.write_cvalue(fx, niche_llval);
 445                     }
 446                 }
 447             }
 448         }
 449         StatementKind::Assign(to_place, rval) => {
 450             let lval = trans_place(fx, to_place);
 451             let dest_layout = lval.layout();
 452             match &**rval {
 453                 Rvalue::Use(operand) => {
 454                     let val = trans_operand(fx, operand);
 455                     lval.write_cvalue(fx, val);
 456                 }
 457                 Rvalue::Ref(_, _, place) => {
 458                     let place = trans_place(fx, place);
 459                     place.write_place_ref(fx, lval);
 460                 }
 461                 Rvalue::BinaryOp(bin_op, lhs, rhs) => {
 462                     let ty = fx.monomorphize(&lhs.ty(fx.mir, fx.tcx));
 463                     let lhs = trans_operand(fx, lhs);
 464                     let rhs = trans_operand(fx, rhs);
 465
 466                     let res = match ty.sty {
 467                         ty::Bool => trans_bool_binop(fx, *bin_op, lhs, rhs, lval.layout().ty),
 468                         ty::Uint(_) => {
 469                             trans_int_binop(fx, *bin_op, lhs, rhs, lval.layout().ty, false)
 470                         }
 471                         ty::Int(_) => {
 472                             trans_int_binop(fx, *bin_op, lhs, rhs, lval.layout().ty, true)
 473                         }
 474                         ty::Float(_) => trans_float_binop(fx, *bin_op, lhs, rhs, lval.layout().ty),
 475                         ty::Char => trans_char_binop(fx, *bin_op, lhs, rhs, lval.layout().ty),
 476                         ty::RawPtr(..) => trans_ptr_binop(fx, *bin_op, lhs, rhs, lval.layout().ty),
 477                         ty::FnPtr(..) => trans_ptr_binop(fx, *bin_op, lhs, rhs, lval.layout().ty),
 478                         _ => unimplemented!("binop {:?} for {:?}", bin_op, ty),
 479                     };
 480                     lval.write_cvalue(fx, res);
 481                 }
 482                 Rvalue::CheckedBinaryOp(bin_op, lhs, rhs) => {
 483                     let ty = fx.monomorphize(&lhs.ty(fx.mir, fx.tcx));
 484                     let lhs = trans_operand(fx, lhs);
 485                     let rhs = trans_operand(fx, rhs);
 486
 487                     let res = match ty.sty {
 488                         ty::Uint(_) => {
 489                             trans_checked_int_binop(fx, *bin_op, lhs, rhs, lval.layout().ty, false)
 490                         }
 491                         ty::Int(_) => {
 492                             trans_checked_int_binop(fx, *bin_op, lhs, rhs, lval.layout().ty, true)
 493                         }
 494                         _ => unimplemented!("checked binop {:?} for {:?}", bin_op, ty),
 495                     };
 496                     lval.write_cvalue(fx, res);
 497                 }
 498                 Rvalue::UnaryOp(un_op, operand) => {
 499                     let operand = trans_operand(fx, operand);
 500                     let layout = operand.layout();
 501                     let val = operand.load_scalar(fx);
 502                     let res = match un_op {
 503                         UnOp::Not => {
 504                             match layout.ty.sty {
 505                                 ty::Bool => {
 506                                     let val = fx.bcx.ins().uextend(types::I32, val); // WORKAROUND for CraneStation/cranelift#466
 507                                     let res = fx.bcx.ins().icmp_imm(IntCC::Equal, val, 0);
 508                                     fx.bcx.ins().bint(types::I8, res)
 509                                 }
 510                                 ty::Uint(_) | ty::Int(_) => fx.bcx.ins().bnot(val),
 511                                 _ => unimplemented!("un op Not for {:?}", layout.ty),
 512                             }
 513                         }
 514                         UnOp::Neg => match layout.ty.sty {
 515                             ty::Int(_) => {
 516                                 let clif_ty = fx.clif_type(layout.ty).unwrap();
 517                                 let zero = fx.bcx.ins().iconst(clif_ty, 0);
 518                                 fx.bcx.ins().isub(zero, val)
 519                             }
 520                             ty::Float(_) => fx.bcx.ins().fneg(val),
 521                             _ => unimplemented!("un op Neg for {:?}", layout.ty),
 522                         },
 523                     };
 524                     lval.write_cvalue(fx, CValue::ByVal(res, layout));
 525                 }
 526                 Rvalue::Cast(CastKind::ReifyFnPointer, operand, ty) => {
 527                     let layout = fx.layout_of(ty);
 528                     match fx
 529                         .monomorphize(&operand.ty(&fx.mir.local_decls, fx.tcx))
 530                         .sty
 531                     {
 532                         ty::FnDef(def_id, substs) => {
 533                             let func_ref = fx.get_function_ref(
 534                                 Instance::resolve(fx.tcx, ParamEnv::reveal_all(), def_id, substs)
 535                                     .unwrap(),
 536                             );
 537                             let func_addr = fx.bcx.ins().func_addr(fx.pointer_type, func_ref);
 538                             lval.write_cvalue(fx, CValue::ByVal(func_addr, layout));
 539                         }
 540                         _ => bug!("Trying to ReifyFnPointer on non FnDef {:?}", ty),
 541                     }
 542                 }
 543                 Rvalue::Cast(CastKind::UnsafeFnPointer, operand, ty)
 544                 | Rvalue::Cast(CastKind::MutToConstPointer, operand, ty) => {
 545                     let operand = trans_operand(fx, operand);
 546                     let layout = fx.layout_of(ty);
 547                     lval.write_cvalue(fx, operand.unchecked_cast_to(layout));
 548                 }
 549                 Rvalue::Cast(CastKind::Misc, operand, to_ty) => {
 550                     let operand = trans_operand(fx, operand);
 551                     let from_ty = operand.layout().ty;
 552
 553                     fn is_fat_ptr<'a, 'tcx: 'a>(fx: &FunctionCx<'a, 'tcx, impl Backend>, ty: Ty<'tcx>) -> bool {
 554                         ty
 555                             .builtin_deref(true)
 556                             .map(|ty::TypeAndMut {ty: pointee_ty, mutbl: _ }| fx.layout_of(pointee_ty).is_unsized())
 557                             .unwrap_or(false)
 558                     }
 559
 560                     if is_fat_ptr(fx, from_ty) {
 561                         if is_fat_ptr(fx, to_ty) {
 562                             // fat-ptr -> fat-ptr
 563                             lval.write_cvalue(fx, operand.unchecked_cast_to(dest_layout));
 564                         } else {
 565                             // fat-ptr -> thin-ptr
 566                             let (ptr, _extra) = operand.load_scalar_pair(fx);
 567                             lval.write_cvalue(fx, CValue::ByVal(ptr, dest_layout))
 568                         }
 569                     } else if let ty::Adt(adt_def, _substs) = from_ty.sty {
 570                         // enum -> discriminant value
 571                         assert!(adt_def.is_enum());
 572                         match to_ty.sty {
 573                             ty::Uint(_) | ty::Int(_) => {},
 574                             _ => unreachable!("cast adt {} -> {}", from_ty, to_ty),
 575                         }
 576
 577                         // FIXME avoid forcing to stack
 578                         let place =
 579                             CPlace::Addr(operand.force_stack(fx), None, operand.layout());
 580                         let discr = trans_get_discriminant(fx, place, fx.layout_of(to_ty));
 581                         lval.write_cvalue(fx, discr);
 582                     } else {
 583                         let from_clif_ty = fx.clif_type(from_ty).unwrap();
 584                         let to_clif_ty = fx.clif_type(to_ty).unwrap();
 585                         let from = operand.load_scalar(fx);
 586
 587                         let signed = match from_ty.sty {
 588                             ty::Ref(..) | ty::RawPtr(..) | ty::FnPtr(..) | ty::Char | ty::Uint(..) | ty::Bool => false,
 589                             ty::Int(..) => true,
 590                             ty::Float(..) => false, // `signed` is unused for floats
 591                             _ => panic!("{}", from_ty),
 592                         };
 593
 594                         let res = if from_clif_ty.is_int() && to_clif_ty.is_int() {
 595                             // int-like -> int-like
 596                             crate::common::clif_intcast(
 597                                 fx,
 598                                 from,
 599                                 to_clif_ty,
 600                                 signed,
 601                             )
 602                         } else if from_clif_ty.is_int() && to_clif_ty.is_float() {
 603                             // int-like -> float
 604                             // FIXME missing encoding for fcvt_from_sint.f32.i8
 605                             let from = if from_clif_ty == types::I8 || from_clif_ty == types::I16 {
 606                                 fx.bcx.ins().uextend(types::I32, from)
 607                             } else {
 608                                 from
 609                             };
 610                             if signed {
 611                                 fx.bcx.ins().fcvt_from_sint(to_clif_ty, from)
 612                             } else {
 613                                 fx.bcx.ins().fcvt_from_uint(to_clif_ty, from)
 614                             }
 615                         } else if from_clif_ty.is_float() && to_clif_ty.is_int() {
 616                             // float -> int-like
 617                             let from = operand.load_scalar(fx);
 618                             if signed {
 619                                 fx.bcx.ins().fcvt_to_sint_sat(to_clif_ty, from)
 620                             } else {
 621                                 fx.bcx.ins().fcvt_to_uint_sat(to_clif_ty, from)
 622                             }
 623                         } else if from_clif_ty.is_float() && to_clif_ty.is_float() {
 624                             // float -> float
 625                             match (from_clif_ty, to_clif_ty) {
 626                                 (types::F32, types::F64) => {
 627                                     fx.bcx.ins().fpromote(types::F64, from)
 628                                 }
 629                                 (types::F64, types::F32) => {
 630                                     fx.bcx.ins().fdemote(types::F32, from)
 631                                 }
 632                                 _ => from,
 633                             }
 634                         } else {
 635                             unimpl!("rval misc {:?} {:?}", from_ty, to_ty)
 636                         };
 637                         lval.write_cvalue(fx, CValue::ByVal(res, dest_layout));
 638                     }
 639                 }
 640                 Rvalue::Cast(CastKind::ClosureFnPointer(_), operand, _ty) => {
 641                     let operand = trans_operand(fx, operand);
 642                     match operand.layout().ty.sty {
 643                         ty::Closure(def_id, substs) => {
 644                             let instance = rustc_mir::monomorphize::resolve_closure(
 645                                 fx.tcx,
 646                                 def_id,
 647                                 substs,
 648                                 ty::ClosureKind::FnOnce,
 649                             );
 650                             let func_ref = fx.get_function_ref(instance);
 651                             let func_addr = fx.bcx.ins().func_addr(fx.pointer_type, func_ref);
 652                             lval.write_cvalue(fx, CValue::ByVal(func_addr, lval.layout()));
 653                         }
 654                         _ => {
 655                             bug!("{} cannot be cast to a fn ptr", operand.layout().ty)
 656                         }
 657                     }
 658                 }
 659                 Rvalue::Cast(CastKind::Unsize, operand, _ty) => {
 660                     let operand = trans_operand(fx, operand);
 661                     operand.unsize_value(fx, lval);
 662                 }
 663                 Rvalue::Discriminant(place) => {
 664                     let place = trans_place(fx, place);
 665                     let discr = trans_get_discriminant(fx, place, dest_layout);
 666                     lval.write_cvalue(fx, discr);
 667                 }
 668                 Rvalue::Repeat(operand, times) => {
 669                     let operand = trans_operand(fx, operand);
 670                     for i in 0..*times {
 671                         let index = fx.bcx.ins().iconst(fx.pointer_type, i as i64);
 672                         let to = lval.place_index(fx, index);
 673                         to.write_cvalue(fx, operand);
 674                     }
 675                 }
 676                 Rvalue::Len(place) => {
 677                     let place = trans_place(fx, place);
 678                     let usize_layout = fx.layout_of(fx.tcx.types.usize);
 679                     let len = codegen_array_len(fx, place);
 680                     lval.write_cvalue(fx, CValue::ByVal(len, usize_layout));
 681                 }
 682                 Rvalue::NullaryOp(NullOp::Box, content_ty) => {
 683                     use rustc::middle::lang_items::ExchangeMallocFnLangItem;
 684
 685                     let usize_type = fx.clif_type(fx.tcx.types.usize).unwrap();
 686                     let layout = fx.layout_of(content_ty);
 687                     let llsize = fx.bcx.ins().iconst(usize_type, layout.size.bytes() as i64);
 688                     let llalign = fx
 689                         .bcx
 690                         .ins()
 691                         .iconst(usize_type, layout.align.abi.bytes() as i64);
 692                     let box_layout = fx.layout_of(fx.tcx.mk_box(content_ty));
 693
 694                     // Allocate space:
 695                     let def_id = match fx.tcx.lang_items().require(ExchangeMallocFnLangItem) {
 696                         Ok(id) => id,
 697                         Err(s) => {
 698                             fx.tcx
 699                                 .sess
 700                                 .fatal(&format!("allocation of `{}` {}", box_layout.ty, s));
 701                         }
 702                     };
 703                     let instance = ty::Instance::mono(fx.tcx, def_id);
 704                     let func_ref = fx.get_function_ref(instance);
 705                     let call = fx.bcx.ins().call(func_ref, &[llsize, llalign]);
 706                     let ptr = fx.bcx.inst_results(call)[0];
 707                     lval.write_cvalue(fx, CValue::ByVal(ptr, box_layout));
 708                 }
 709                 Rvalue::NullaryOp(NullOp::SizeOf, ty) => {
 710                     assert!(lval
 711                         .layout()
 712                         .ty
 713                         .is_sized(fx.tcx.at(DUMMY_SP), ParamEnv::reveal_all()));
 714                     let ty_size = fx.layout_of(ty).size.bytes();
 715                     let val = CValue::const_val(fx, fx.tcx.types.usize, ty_size as i64);
 716                     lval.write_cvalue(fx, val);
 717                 }
 718                 Rvalue::Aggregate(kind, operands) => match **kind {
 719                     AggregateKind::Array(_ty) => {
 720                         for (i, operand) in operands.into_iter().enumerate() {
 721                             let operand = trans_operand(fx, operand);
 722                             let index = fx.bcx.ins().iconst(fx.pointer_type, i as i64);
 723                             let to = lval.place_index(fx, index);
 724                             to.write_cvalue(fx, operand);
 725                         }
 726                     }
 727                     _ => unimpl!("shouldn't exist at trans {:?}", rval),
 728                 },
 729             }
 730         }
 731         StatementKind::StorageLive(_)
 732         | StatementKind::StorageDead(_)
 733         | StatementKind::Nop
 734         | StatementKind::FakeRead(..)
 735         | StatementKind::Retag { .. }
 736         | StatementKind::AscribeUserType(..) => {}
 737
 738         StatementKind::InlineAsm { .. } => unimpl!("Inline assembly is not supported"),
 739     }
 740 }
 741
 742 fn codegen_array_len<'a, 'tcx: 'a>(
 743     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 744     place: CPlace<'tcx>,
 745 ) -> Value {
 746     match place.layout().ty.sty {
 747         ty::Array(_elem_ty, len) => {
 748             let len = crate::constant::force_eval_const(fx, len).unwrap_usize(fx.tcx) as i64;
 749             fx.bcx.ins().iconst(fx.pointer_type, len)
 750         }
 751         ty::Slice(_elem_ty) => place
 752             .to_addr_maybe_unsized(fx)
 753             .1
 754             .expect("Length metadata for slice place"),
 755         _ => bug!("Rvalue::Len({:?})", place),
 756     }
 757 }
 758
 759 pub fn trans_get_discriminant<'a, 'tcx: 'a>(
 760     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 761     place: CPlace<'tcx>,
 762     dest_layout: TyLayout<'tcx>,
 763 ) -> CValue<'tcx> {
 764     let layout = place.layout();
 765
 766     if layout.abi == layout::Abi::Uninhabited {
 767         return trap_unreachable_ret_value(fx, dest_layout, "[panic] Tried to get discriminant for uninhabited type.");
 768     }
 769
 770     let (discr_scalar, discr_kind) = match &layout.variants {
 771         layout::Variants::Single { index } => {
 772             let discr_val = layout
 773                 .ty
 774                 .ty_adt_def()
 775                 .map_or(index.as_u32() as u128, |def| {
 776                     def.discriminant_for_variant(fx.tcx, *index).val
 777                 });
 778             return CValue::const_val(fx, dest_layout.ty, discr_val as u64 as i64);
 779         }
 780         layout::Variants::Multiple { discr, discr_kind, variants: _ } => (discr, discr_kind),
 781     };
 782
 783     let discr = place.place_field(fx, mir::Field::new(0)).to_cvalue(fx);
 784     let discr_ty = discr.layout().ty;
 785     let lldiscr = discr.load_scalar(fx);
 786     match discr_kind {
 787         layout::DiscriminantKind::Tag => {
 788             let signed = match discr_scalar.value {
 789                 layout::Int(_, signed) => signed,
 790                 _ => false,
 791             };
 792             let val = clif_intcast(fx, lldiscr, fx.clif_type(dest_layout.ty).unwrap(), signed);
 793             return CValue::ByVal(val, dest_layout);
 794         }
 795         layout::DiscriminantKind::Niche {
 796             dataful_variant,
 797             ref niche_variants,
 798             niche_start,
 799         } => {
 800             let niche_llty = fx.clif_type(discr_ty).unwrap();
 801             let dest_clif_ty = fx.clif_type(dest_layout.ty).unwrap();
 802             if niche_variants.start() == niche_variants.end() {
 803                 let b = fx
 804                     .bcx
 805                     .ins()
 806                     .icmp_imm(IntCC::Equal, lldiscr, *niche_start as u64 as i64);
 807                 let if_true = fx
 808                     .bcx
 809                     .ins()
 810                     .iconst(dest_clif_ty, niche_variants.start().as_u32() as i64);
 811                 let if_false = fx
 812                     .bcx
 813                     .ins()
 814                     .iconst(dest_clif_ty, dataful_variant.as_u32() as i64);
 815                 let val = fx.bcx.ins().select(b, if_true, if_false);
 816                 return CValue::ByVal(val, dest_layout);
 817             } else {
 818                 // Rebase from niche values to discriminant values.
 819                 let delta = niche_start.wrapping_sub(niche_variants.start().as_u32() as u128);
 820                 let delta = fx.bcx.ins().iconst(niche_llty, delta as u64 as i64);
 821                 let lldiscr = fx.bcx.ins().isub(lldiscr, delta);
 822                 let b = fx.bcx.ins().icmp_imm(
 823                     IntCC::UnsignedLessThanOrEqual,
 824                     lldiscr,
 825                     niche_variants.end().as_u32() as i64,
 826                 );
 827                 let if_true =
 828                     clif_intcast(fx, lldiscr, fx.clif_type(dest_layout.ty).unwrap(), false);
 829                 let if_false = fx
 830                     .bcx
 831                     .ins()
 832                     .iconst(dest_clif_ty, dataful_variant.as_u32() as i64);
 833                 let val = fx.bcx.ins().select(b, if_true, if_false);
 834                 return CValue::ByVal(val, dest_layout);
 835             }
 836         }
 837     }
 838 }
 839
 840 macro_rules! binop_match {
 841     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, bug) => {
 842         bug!("binop {} on {} lhs: {:?} rhs: {:?}", stringify!($var), $bug_fmt, $lhs, $rhs)
 843     };
 844     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, icmp($cc:ident)) => {{
 845         assert_eq!($fx.tcx.types.bool, $ret_ty);
 846         let ret_layout = $fx.layout_of($ret_ty);
 847
 848         let b = $fx.bcx.ins().icmp(IntCC::$cc, $lhs, $rhs);
 849         CValue::ByVal($fx.bcx.ins().bint(types::I8, b), ret_layout)
 850     }};
 851     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, fcmp($cc:ident)) => {{
 852         assert_eq!($fx.tcx.types.bool, $ret_ty);
 853         let ret_layout = $fx.layout_of($ret_ty);
 854         let b = $fx.bcx.ins().fcmp(FloatCC::$cc, $lhs, $rhs);
 855         CValue::ByVal($fx.bcx.ins().bint(types::I8, b), ret_layout)
 856     }};
 857     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, custom(|| $body:expr)) => {{
 858         $body
 859     }};
 860     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, $name:ident) => {{
 861         let ret_layout = $fx.layout_of($ret_ty);
 862         CValue::ByVal($fx.bcx.ins().$name($lhs, $rhs), ret_layout)
 863     }};
 864     (
 865         $fx:expr, $bin_op:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, $bug_fmt:expr;
 866         $(
 867             $var:ident ($sign:pat) $name:tt $( ( $($next:tt)* ) )? ;
 868         )*
 869     ) => {{
 870         let lhs = $lhs.load_scalar($fx);
 871         let rhs = $rhs.load_scalar($fx);
 872         match ($bin_op, $signed) {
 873             $(
 874                 (BinOp::$var, $sign) => binop_match!(@single $fx, $bug_fmt, $var, $signed, lhs, rhs, $ret_ty, $name $( ( $($next)* ) )?),
 875             )*
 876         }
 877     }}
 878 }
 879
 880 fn trans_bool_binop<'a, 'tcx: 'a>(
 881     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 882     bin_op: BinOp,
 883     lhs: CValue<'tcx>,
 884     rhs: CValue<'tcx>,
 885     ty: Ty<'tcx>,
 886 ) -> CValue<'tcx> {
 887     let res = binop_match! {
 888         fx, bin_op, false, lhs, rhs, ty, "bool";
 889         Add (_) bug;
 890         Sub (_) bug;
 891         Mul (_) bug;
 892         Div (_) bug;
 893         Rem (_) bug;
 894         BitXor (_) bxor;
 895         BitAnd (_) band;
 896         BitOr (_) bor;
 897         Shl (_) bug;
 898         Shr (_) bug;
 899
 900         Eq (_) icmp(Equal);
 901         Lt (_) icmp(UnsignedLessThan);
 902         Le (_) icmp(UnsignedLessThanOrEqual);
 903         Ne (_) icmp(NotEqual);
 904         Ge (_) icmp(UnsignedGreaterThanOrEqual);
 905         Gt (_) icmp(UnsignedGreaterThan);
 906
 907         Offset (_) bug;
 908     };
 909
 910     res
 911 }
 912
 913 pub fn trans_int_binop<'a, 'tcx: 'a>(
 914     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 915     bin_op: BinOp,
 916     lhs: CValue<'tcx>,
 917     rhs: CValue<'tcx>,
 918     out_ty: Ty<'tcx>,
 919     signed: bool,
 920 ) -> CValue<'tcx> {
 921     if bin_op != BinOp::Shl && bin_op != BinOp::Shr {
 922         assert_eq!(
 923             lhs.layout().ty,
 924             rhs.layout().ty,
 925             "int binop requires lhs and rhs of same type"
 926         );
 927     }
 928     binop_match! {
 929         fx, bin_op, signed, lhs, rhs, out_ty, "int/uint";
 930         Add (_) iadd;
 931         Sub (_) isub;
 932         Mul (_) imul;
 933         Div (false) udiv;
 934         Div (true) sdiv;
 935         Rem (false) urem;
 936         Rem (true) srem;
 937         BitXor (_) bxor;
 938         BitAnd (_) band;
 939         BitOr (_) bor;
 940         Shl (_) ishl;
 941         Shr (false) ushr;
 942         Shr (true) sshr;
 943
 944         Eq (_) icmp(Equal);
 945         Lt (false) icmp(UnsignedLessThan);
 946         Lt (true) icmp(SignedLessThan);
 947         Le (false) icmp(UnsignedLessThanOrEqual);
 948         Le (true) icmp(SignedLessThanOrEqual);
 949         Ne (_) icmp(NotEqual);
 950         Ge (false) icmp(UnsignedGreaterThanOrEqual);
 951         Ge (true) icmp(SignedGreaterThanOrEqual);
 952         Gt (false) icmp(UnsignedGreaterThan);
 953         Gt (true) icmp(SignedGreaterThan);
 954
 955         Offset (_) bug;
 956     }
 957 }
 958
 959 pub fn trans_checked_int_binop<'a, 'tcx: 'a>(
 960     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 961     bin_op: BinOp,
 962     in_lhs: CValue<'tcx>,
 963     in_rhs: CValue<'tcx>,
 964     out_ty: Ty<'tcx>,
 965     signed: bool,
 966 ) -> CValue<'tcx> {
 967     if bin_op != BinOp::Shl && bin_op != BinOp::Shr {
 968         assert_eq!(
 969             in_lhs.layout().ty,
 970             in_rhs.layout().ty,
 971             "checked int binop requires lhs and rhs of same type"
 972         );
 973     }
 974
 975     let lhs = in_lhs.load_scalar(fx);
 976     let rhs = in_rhs.load_scalar(fx);
 977     let res = match bin_op {
 978         BinOp::Add => fx.bcx.ins().iadd(lhs, rhs),
 979         BinOp::Sub => fx.bcx.ins().isub(lhs, rhs),
 980         BinOp::Mul => fx.bcx.ins().imul(lhs, rhs),
 981         BinOp::Shl => fx.bcx.ins().ishl(lhs, rhs),
 982         BinOp::Shr => {
 983             if !signed {
 984                 fx.bcx.ins().ushr(lhs, rhs)
 985             } else {
 986                 fx.bcx.ins().sshr(lhs, rhs)
 987             }
 988         }
 989         _ => bug!(
 990             "binop {:?} on checked int/uint lhs: {:?} rhs: {:?}",
 991             bin_op,
 992             in_lhs,
 993             in_rhs
 994         ),
 995     };
 996
 997     // TODO: check for overflow
 998     let has_overflow = fx.bcx.ins().iconst(types::I8, 0);
 999
1000     let out_place = CPlace::new_stack_slot(fx, out_ty);
1001     let out_layout = out_place.layout();
1002     out_place.write_cvalue(fx, CValue::ByValPair(res, has_overflow, out_layout));
1003
1004     out_place.to_cvalue(fx)
1005 }
1006
1007 fn trans_float_binop<'a, 'tcx: 'a>(
1008     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
1009     bin_op: BinOp,
1010     lhs: CValue<'tcx>,
1011     rhs: CValue<'tcx>,
1012     ty: Ty<'tcx>,
1013 ) -> CValue<'tcx> {
1014     let res = binop_match! {
1015         fx, bin_op, false, lhs, rhs, ty, "float";
1016         Add (_) fadd;
1017         Sub (_) fsub;
1018         Mul (_) fmul;
1019         Div (_) fdiv;
1020         Rem (_) custom(|| {
1021             assert_eq!(lhs.layout().ty, ty);
1022             assert_eq!(rhs.layout().ty, ty);
1023             match ty.sty {
1024                 ty::Float(FloatTy::F32) => fx.easy_call("fmodf", &[lhs, rhs], ty),
1025                 ty::Float(FloatTy::F64) => fx.easy_call("fmod", &[lhs, rhs], ty),
1026                 _ => bug!(),
1027             }
1028         });
1029         BitXor (_) bxor;
1030         BitAnd (_) band;
1031         BitOr (_) bor;
1032         Shl (_) bug;
1033         Shr (_) bug;
1034
1035         Eq (_) fcmp(Equal);
1036         Lt (_) fcmp(LessThan);
1037         Le (_) fcmp(LessThanOrEqual);
1038         Ne (_) fcmp(NotEqual);
1039         Ge (_) fcmp(GreaterThanOrEqual);
1040         Gt (_) fcmp(GreaterThan);
1041
1042         Offset (_) bug;
1043     };
1044
1045     res
1046 }
1047
1048 fn trans_char_binop<'a, 'tcx: 'a>(
1049     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
1050     bin_op: BinOp,
1051     lhs: CValue<'tcx>,
1052     rhs: CValue<'tcx>,
1053     ty: Ty<'tcx>,
1054 ) -> CValue<'tcx> {
1055     let res = binop_match! {
1056         fx, bin_op, false, lhs, rhs, ty, "char";
1057         Add (_) bug;
1058         Sub (_) bug;
1059         Mul (_) bug;
1060         Div (_) bug;
1061         Rem (_) bug;
1062         BitXor (_) bug;
1063         BitAnd (_) bug;
1064         BitOr (_) bug;
1065         Shl (_) bug;
1066         Shr (_) bug;
1067
1068         Eq (_) icmp(Equal);
1069         Lt (_) icmp(UnsignedLessThan);
1070         Le (_) icmp(UnsignedLessThanOrEqual);
1071         Ne (_) icmp(NotEqual);
1072         Ge (_) icmp(UnsignedGreaterThanOrEqual);
1073         Gt (_) icmp(UnsignedGreaterThan);
1074
1075         Offset (_) bug;
1076     };
1077
1078     res
1079 }
1080
1081 fn trans_ptr_binop<'a, 'tcx: 'a>(
1082     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
1083     bin_op: BinOp,
1084     lhs: CValue<'tcx>,
1085     rhs: CValue<'tcx>,
1086     ret_ty: Ty<'tcx>,
1087 ) -> CValue<'tcx> {
1088     let not_fat = match lhs.layout().ty.sty {
1089         ty::RawPtr(TypeAndMut { ty, mutbl: _ }) => {
1090             ty.is_sized(fx.tcx.at(DUMMY_SP), ParamEnv::reveal_all())
1091         }
1092         ty::FnPtr(..) => true,
1093         _ => bug!("trans_ptr_binop on non ptr"),
1094     };
1095     if not_fat {
1096         if let BinOp::Offset = bin_op {
1097             let (base, offset) = (lhs, rhs.load_scalar(fx));
1098             let pointee_ty = base.layout().ty.builtin_deref(true).unwrap().ty;
1099             let pointee_size = fx.layout_of(pointee_ty).size.bytes();
1100             let ptr_diff = fx.bcx.ins().imul_imm(offset, pointee_size as i64);
1101             let base_val = base.load_scalar(fx);
1102             let res = fx.bcx.ins().iadd(base_val, ptr_diff);
1103             return CValue::ByVal(res, base.layout());
1104         }
1105
1106         binop_match! {
1107             fx, bin_op, false, lhs, rhs, ret_ty, "ptr";
1108             Add (_) bug;
1109             Sub (_) bug;
1110             Mul (_) bug;
1111             Div (_) bug;
1112             Rem (_) bug;
1113             BitXor (_) bug;
1114             BitAnd (_) bug;
1115             BitOr (_) bug;
1116             Shl (_) bug;
1117             Shr (_) bug;
1118
1119             Eq (_) icmp(Equal);
1120             Lt (_) icmp(UnsignedLessThan);
1121             Le (_) icmp(UnsignedLessThanOrEqual);
1122             Ne (_) icmp(NotEqual);
1123             Ge (_) icmp(UnsignedGreaterThanOrEqual);
1124             Gt (_) icmp(UnsignedGreaterThan);
1125
1126             Offset (_) bug; // Handled above
1127         }
1128     } else {
1129         let (lhs_ptr, lhs_extra) = lhs.load_scalar_pair(fx);
1130         let (rhs_ptr, rhs_extra) = rhs.load_scalar_pair(fx);
1131         let res = match bin_op {
1132             BinOp::Eq => {
1133                 let ptr_eq = fx.bcx.ins().icmp(IntCC::Equal, lhs_ptr, rhs_ptr);
1134                 let extra_eq = fx.bcx.ins().icmp(IntCC::Equal, lhs_extra, rhs_extra);
1135                 fx.bcx.ins().band(ptr_eq, extra_eq)
1136             }
1137             BinOp::Ne => {
1138                 let ptr_ne = fx.bcx.ins().icmp(IntCC::NotEqual, lhs_ptr, rhs_ptr);
1139                 let extra_ne = fx.bcx.ins().icmp(IntCC::NotEqual, lhs_extra, rhs_extra);
1140                 fx.bcx.ins().bor(ptr_ne, extra_ne)
1141             }
1142             _ => unimplemented!(
1143                 "trans_ptr_binop({:?}, <fat ptr>, <fat ptr>) not implemented",
1144                 bin_op
1145             ),
1146         };
1147
1148         assert_eq!(fx.tcx.types.bool, ret_ty);
1149         let ret_layout = fx.layout_of(ret_ty);
1150         CValue::ByVal(fx.bcx.ins().bint(types::I8, res), ret_layout)
1151     }
1152 }
1153
1154 pub fn trans_place<'a, 'tcx: 'a>(
1155     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
1156     place: &Place<'tcx>,
1157 ) -> CPlace<'tcx> {
1158     match place {
1159         Place::Base(base) => match base {
1160             PlaceBase::Local(local) => fx.get_local_place(*local),
1161             PlaceBase::Static(static_) => match static_.kind {
1162                 StaticKind::Static(def_id) => {
1163                     crate::constant::codegen_static_ref(fx, def_id, static_.ty)
1164                 }
1165                 StaticKind::Promoted(promoted) => {
1166                     crate::constant::trans_promoted(fx, promoted, static_.ty)
1167                 }
1168             }
1169         }
1170         Place::Projection(projection) => {
1171             let base = trans_place(fx, &projection.base);
1172             match projection.elem {
1173                 ProjectionElem::Deref => base.place_deref(fx),
1174                 ProjectionElem::Field(field, _ty) => base.place_field(fx, field),
1175                 ProjectionElem::Index(local) => {
1176                     let index = fx.get_local_place(local).to_cvalue(fx).load_scalar(fx);
1177                     base.place_index(fx, index)
1178                 }
1179                 ProjectionElem::ConstantIndex {
1180                     offset,
1181                     min_length: _,
1182                     from_end,
1183                 } => {
1184                     let index = if !from_end {
1185                         fx.bcx.ins().iconst(fx.pointer_type, offset as i64)
1186                     } else {
1187                         let len = codegen_array_len(fx, base);
1188                         fx.bcx.ins().iadd_imm(len, -(offset as i64))
1189                     };
1190                     base.place_index(fx, index)
1191                 }
1192                 ProjectionElem::Subslice { from, to } => {
1193                     // These indices are generated by slice patterns.
1194                     // slice[from:-to] in Python terms.
1195
1196                     match base.layout().ty.sty {
1197                         ty::Array(elem_ty, len) => {
1198                             let elem_layout = fx.layout_of(elem_ty);
1199                             let ptr = base.to_addr(fx);
1200                             let len = crate::constant::force_eval_const(fx, len).unwrap_usize(fx.tcx);
1201                             CPlace::Addr(
1202                                 fx.bcx.ins().iadd_imm(ptr, elem_layout.size.bytes() as i64 * from as i64),
1203                                 None,
1204                                 fx.layout_of(fx.tcx.mk_array(elem_ty, len - from as u64 - to as u64)),
1205                             )
1206                         }
1207                         ty::Slice(elem_ty) => {
1208                             let elem_layout = fx.layout_of(elem_ty);
1209                             let (ptr, len) = base.to_addr_maybe_unsized(fx);
1210                             let len = len.unwrap();
1211                             CPlace::Addr(
1212                                 fx.bcx.ins().iadd_imm(ptr, elem_layout.size.bytes() as i64 * from as i64),
1213                                 Some(fx.bcx.ins().iadd_imm(len, -(from as i64 + to as i64))),
1214                                 base.layout(),
1215                             )
1216                         }
1217                         _ => unreachable!(),
1218                     }
1219                 }
1220                 ProjectionElem::Downcast(_adt_def, variant) => base.downcast_variant(fx, variant),
1221             }
1222         }
1223     }
1224 }
1225
1226 pub fn trans_operand<'a, 'tcx>(
1227     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
1228     operand: &Operand<'tcx>,
1229 ) -> CValue<'tcx> {
1230     match operand {
1231         Operand::Move(place) | Operand::Copy(place) => {
1232             let cplace = trans_place(fx, place);
1233             cplace.to_cvalue(fx)
1234         }
1235         Operand::Constant(const_) => crate::constant::trans_constant(fx, const_),
1236     }
1237 }