src/base.rs

   1 use rustc::ty::adjustment::PointerCast;
   2
   3 use crate::prelude::*;
   4
   5 pub fn trans_fn<'a, 'clif, 'tcx: 'a, B: Backend + 'static>(
   6     cx: &mut crate::CodegenCx<'clif, 'tcx, B>,
   7     instance: Instance<'tcx>,
   8     linkage: Linkage,
   9 ) {
  10     let tcx = cx.tcx;
  11
  12     let mir = tcx.instance_mir(instance.def);
  13
  14     // Declare function
  15     let (name, sig) = get_function_name_and_sig(tcx, instance, false);
  16     let func_id = cx.module.declare_function(&name, linkage, &sig).unwrap();
  17     let mut debug_context = cx
  18         .debug_context
  19         .as_mut()
  20         .map(|debug_context| FunctionDebugContext::new(tcx, debug_context, mir, &name, &sig));
  21
  22     // Make FunctionBuilder
  23     let mut func = Function::with_name_signature(ExternalName::user(0, 0), sig);
  24     let mut func_ctx = FunctionBuilderContext::new();
  25     let mut bcx = FunctionBuilder::new(&mut func, &mut func_ctx);
  26
  27     // Predefine ebb's
  28     let start_ebb = bcx.create_ebb();
  29     let mut ebb_map: HashMap<BasicBlock, Ebb> = HashMap::new();
  30     for (bb, _bb_data) in mir.basic_blocks().iter_enumerated() {
  31         ebb_map.insert(bb, bcx.create_ebb());
  32     }
  33
  34     // Make FunctionCx
  35     let pointer_type = cx.module.target_config().pointer_type();
  36     let clif_comments = crate::pretty_clif::CommentWriter::new(tcx, instance);
  37
  38     let mut fx = FunctionCx {
  39         tcx,
  40         module: cx.module,
  41         pointer_type,
  42
  43         instance,
  44         mir,
  45
  46         bcx,
  47         ebb_map,
  48         local_map: HashMap::new(),
  49
  50         clif_comments,
  51         constants: &mut cx.ccx,
  52         caches: &mut cx.caches,
  53         source_info_set: indexmap::IndexSet::new(),
  54     };
  55
  56     with_unimpl_span(fx.mir.span, || {
  57         crate::abi::codegen_fn_prelude(&mut fx, start_ebb);
  58         codegen_fn_content(&mut fx);
  59     });
  60
  61     // Recover all necessary data from fx, before accessing func will prevent future access to it.
  62     let instance = fx.instance;
  63     let clif_comments = fx.clif_comments;
  64     let source_info_set = fx.source_info_set;
  65
  66     #[cfg(debug_assertions)]
  67     crate::pretty_clif::write_clif_file(cx.tcx, "unopt", instance, &func, &clif_comments, None);
  68
  69     // Verify function
  70     verify_func(tcx, &clif_comments, &func);
  71
  72     // Define function
  73     let context = &mut cx.caches.context;
  74     context.func = func;
  75     cx.module
  76         .define_function(func_id, context)
  77         .unwrap();
  78
  79     let value_ranges = context.build_value_labels_ranges(cx.module.isa()).expect("value location ranges");
  80
  81     // Write optimized function to file for debugging
  82     #[cfg(debug_assertions)]
  83     crate::pretty_clif::write_clif_file(cx.tcx, "opt", instance, &context.func, &clif_comments, Some(&value_ranges));
  84
  85     // Define debuginfo for function
  86     let isa = cx.module.isa();
  87     debug_context
  88         .as_mut()
  89         .map(|x| x.define(tcx, context, isa, &source_info_set));
  90
  91     // Clear context to make it usable for the next function
  92     context.clear();
  93 }
  94
  95 fn verify_func(tcx: TyCtxt, writer: &crate::pretty_clif::CommentWriter, func: &Function) {
  96     let flags = settings::Flags::new(settings::builder());
  97     match ::cranelift::codegen::verify_function(&func, &flags) {
  98         Ok(_) => {}
  99         Err(err) => {
 100             tcx.sess.err(&format!("{:?}", err));
 101             let pretty_error = ::cranelift::codegen::print_errors::pretty_verifier_error(
 102                 &func,
 103                 None,
 104                 Some(Box::new(writer)),
 105                 err,
 106             );
 107             tcx.sess
 108                 .fatal(&format!("cranelift verify error:\n{}", pretty_error));
 109         }
 110     }
 111 }
 112
 113 fn codegen_fn_content<'a, 'tcx: 'a>(fx: &mut FunctionCx<'a, 'tcx, impl Backend>) {
 114     for (bb, bb_data) in fx.mir.basic_blocks().iter_enumerated() {
 115         if bb_data.is_cleanup {
 116             // Unwinding after panicking is not supported
 117             continue;
 118         }
 119
 120         let ebb = fx.get_ebb(bb);
 121         fx.bcx.switch_to_block(ebb);
 122
 123         fx.bcx.ins().nop();
 124         for stmt in &bb_data.statements {
 125             fx.set_debug_loc(stmt.source_info);
 126             trans_stmt(fx, ebb, stmt);
 127         }
 128
 129         #[cfg(debug_assertions)]
 130         {
 131             let mut terminator_head = "\n".to_string();
 132             bb_data
 133                 .terminator()
 134                 .kind
 135                 .fmt_head(&mut terminator_head)
 136                 .unwrap();
 137             let inst = fx.bcx.func.layout.last_inst(ebb).unwrap();
 138             fx.add_comment(inst, terminator_head);
 139         }
 140
 141         fx.set_debug_loc(bb_data.terminator().source_info);
 142
 143         match &bb_data.terminator().kind {
 144             TerminatorKind::Goto { target } => {
 145                 let ebb = fx.get_ebb(*target);
 146                 fx.bcx.ins().jump(ebb, &[]);
 147             }
 148             TerminatorKind::Return => {
 149                 crate::abi::codegen_return(fx);
 150             }
 151             TerminatorKind::Assert {
 152                 cond,
 153                 expected,
 154                 msg,
 155                 target,
 156                 cleanup: _,
 157             } => {
 158                 let cond = trans_operand(fx, cond).load_scalar(fx);
 159                 // TODO HACK brz/brnz for i8/i16 is not yet implemented
 160                 let cond = fx.bcx.ins().uextend(types::I32, cond);
 161                 let target = fx.get_ebb(*target);
 162                 if *expected {
 163                     fx.bcx.ins().brnz(cond, target, &[]);
 164                 } else {
 165                     fx.bcx.ins().brz(cond, target, &[]);
 166                 };
 167                 trap_panic(fx, format!("[panic] Assert {:?} at {:?} failed.", msg, bb_data.terminator().source_info.span));
 168             }
 169
 170             TerminatorKind::SwitchInt {
 171                 discr,
 172                 switch_ty: _,
 173                 values,
 174                 targets,
 175             } => {
 176                 let discr = trans_operand(fx, discr).load_scalar(fx);
 177                 let mut switch = ::cranelift::frontend::Switch::new();
 178                 for (i, value) in values.iter().enumerate() {
 179                     let ebb = fx.get_ebb(targets[i]);
 180                     switch.set_entry(*value as u64, ebb);
 181                 }
 182                 let otherwise_ebb = fx.get_ebb(targets[targets.len() - 1]);
 183                 switch.emit(&mut fx.bcx, discr, otherwise_ebb);
 184             }
 185             TerminatorKind::Call {
 186                 func,
 187                 args,
 188                 destination,
 189                 cleanup: _,
 190                 from_hir_call: _,
 191             } => {
 192                 crate::abi::codegen_terminator_call(fx, func, args, destination);
 193             }
 194             TerminatorKind::Resume | TerminatorKind::Abort => {
 195                 trap_unreachable(fx, "[corruption] Unwinding bb reached.");
 196             }
 197             TerminatorKind::Unreachable => {
 198                 trap_unreachable(fx, "[corruption] Hit unreachable code.");
 199             }
 200             TerminatorKind::Yield { .. }
 201             | TerminatorKind::FalseEdges { .. }
 202             | TerminatorKind::FalseUnwind { .. }
 203             | TerminatorKind::DropAndReplace { .. }
 204             | TerminatorKind::GeneratorDrop => {
 205                 bug!("shouldn't exist at trans {:?}", bb_data.terminator());
 206             }
 207             TerminatorKind::Drop {
 208                 location,
 209                 target,
 210                 unwind: _,
 211             } => {
 212                 let drop_place = trans_place(fx, location);
 213                 crate::abi::codegen_drop(fx, drop_place);
 214
 215                 let target_ebb = fx.get_ebb(*target);
 216                 fx.bcx.ins().jump(target_ebb, &[]);
 217             }
 218         };
 219     }
 220
 221     fx.bcx.seal_all_blocks();
 222     fx.bcx.finalize();
 223 }
 224
 225 fn trans_stmt<'a, 'tcx: 'a>(
 226     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 227     cur_ebb: Ebb,
 228     stmt: &Statement<'tcx>,
 229 ) {
 230     let _print_guard = PrintOnPanic(|| format!("stmt {:?}", stmt));
 231
 232     fx.set_debug_loc(stmt.source_info);
 233
 234     #[cfg(debug_assertions)]
 235     match &stmt.kind {
 236         StatementKind::StorageLive(..) | StatementKind::StorageDead(..) => {} // Those are not very useful
 237         _ => {
 238             let inst = fx.bcx.func.layout.last_inst(cur_ebb).unwrap();
 239             fx.add_comment(inst, format!("{:?}", stmt));
 240         }
 241     }
 242
 243     match &stmt.kind {
 244         StatementKind::SetDiscriminant {
 245             place,
 246             variant_index,
 247         } => {
 248             let place = trans_place(fx, place);
 249             let layout = place.layout();
 250             if layout.for_variant(&*fx, *variant_index).abi == layout::Abi::Uninhabited {
 251                 return;
 252             }
 253             match layout.variants {
 254                 layout::Variants::Single { index } => {
 255                     assert_eq!(index, *variant_index);
 256                 }
 257                 layout::Variants::Multiple {
 258                     discr: _,
 259                     discr_index,
 260                     discr_kind: layout::DiscriminantKind::Tag,
 261                     variants: _,
 262                 } => {
 263                     let ptr = place.place_field(fx, mir::Field::new(discr_index));
 264                     let to = layout
 265                         .ty
 266                         .discriminant_for_variant(fx.tcx, *variant_index)
 267                         .unwrap()
 268                         .val;
 269                     let discr = CValue::const_val(fx, ptr.layout().ty, to);
 270                     ptr.write_cvalue(fx, discr);
 271                 }
 272                 layout::Variants::Multiple {
 273                     discr: _,
 274                     discr_index,
 275                     discr_kind: layout::DiscriminantKind::Niche {
 276                         dataful_variant,
 277                         ref niche_variants,
 278                         niche_start,
 279                     },
 280                     variants: _,
 281                 } => {
 282                     if *variant_index != dataful_variant {
 283                         let niche = place.place_field(fx, mir::Field::new(discr_index));
 284                         //let niche_llty = niche.layout.immediate_llvm_type(bx.cx);
 285                         let niche_value =
 286                             ((variant_index.as_u32() - niche_variants.start().as_u32()) as u128)
 287                                 .wrapping_add(niche_start);
 288                         // FIXME(eddyb) Check the actual primitive type here.
 289                         let niche_llval = if niche_value == 0 {
 290                             CValue::const_val(fx, niche.layout().ty, 0)
 291                         } else {
 292                             CValue::const_val(fx, niche.layout().ty, niche_value)
 293                         };
 294                         niche.write_cvalue(fx, niche_llval);
 295                     }
 296                 }
 297             }
 298         }
 299         StatementKind::Assign(to_place, rval) => {
 300             let lval = trans_place(fx, to_place);
 301             let dest_layout = lval.layout();
 302             match &**rval {
 303                 Rvalue::Use(operand) => {
 304                     let val = trans_operand(fx, operand);
 305                     lval.write_cvalue(fx, val);
 306                 }
 307                 Rvalue::Ref(_, _, place) => {
 308                     let place = trans_place(fx, place);
 309                     place.write_place_ref(fx, lval);
 310                 }
 311                 Rvalue::BinaryOp(bin_op, lhs, rhs) => {
 312                     let ty = fx.monomorphize(&lhs.ty(fx.mir, fx.tcx));
 313                     let lhs = trans_operand(fx, lhs);
 314                     let rhs = trans_operand(fx, rhs);
 315
 316                     let res = match ty.sty {
 317                         ty::Bool => trans_bool_binop(fx, *bin_op, lhs, rhs),
 318                         ty::Uint(_) => {
 319                             trans_int_binop(fx, *bin_op, lhs, rhs, lval.layout().ty, false)
 320                         }
 321                         ty::Int(_) => {
 322                             trans_int_binop(fx, *bin_op, lhs, rhs, lval.layout().ty, true)
 323                         }
 324                         ty::Float(_) => trans_float_binop(fx, *bin_op, lhs, rhs, lval.layout().ty),
 325                         ty::Char => trans_char_binop(fx, *bin_op, lhs, rhs, lval.layout().ty),
 326                         ty::RawPtr(..) => trans_ptr_binop(fx, *bin_op, lhs, rhs, lval.layout().ty),
 327                         ty::FnPtr(..) => trans_ptr_binop(fx, *bin_op, lhs, rhs, lval.layout().ty),
 328                         _ => unimplemented!("binop {:?} for {:?}", bin_op, ty),
 329                     };
 330                     lval.write_cvalue(fx, res);
 331                 }
 332                 Rvalue::CheckedBinaryOp(bin_op, lhs, rhs) => {
 333                     let ty = fx.monomorphize(&lhs.ty(fx.mir, fx.tcx));
 334                     let lhs = trans_operand(fx, lhs);
 335                     let rhs = trans_operand(fx, rhs);
 336
 337                     let res = match ty.sty {
 338                         ty::Uint(_) => {
 339                             trans_checked_int_binop(fx, *bin_op, lhs, rhs, lval.layout().ty, false)
 340                         }
 341                         ty::Int(_) => {
 342                             trans_checked_int_binop(fx, *bin_op, lhs, rhs, lval.layout().ty, true)
 343                         }
 344                         _ => unimplemented!("checked binop {:?} for {:?}", bin_op, ty),
 345                     };
 346                     lval.write_cvalue(fx, res);
 347                 }
 348                 Rvalue::UnaryOp(un_op, operand) => {
 349                     let operand = trans_operand(fx, operand);
 350                     let layout = operand.layout();
 351                     let val = operand.load_scalar(fx);
 352                     let res = match un_op {
 353                         UnOp::Not => {
 354                             match layout.ty.sty {
 355                                 ty::Bool => {
 356                                     let val = fx.bcx.ins().uextend(types::I32, val); // WORKAROUND for CraneStation/cranelift#466
 357                                     let res = fx.bcx.ins().icmp_imm(IntCC::Equal, val, 0);
 358                                     fx.bcx.ins().bint(types::I8, res)
 359                                 }
 360                                 ty::Uint(_) | ty::Int(_) => {
 361                                     fx.bcx.ins().bnot(val)
 362                                 }
 363                                 _ => unimplemented!("un op Not for {:?}", layout.ty),
 364                             }
 365                         }
 366                         UnOp::Neg => match layout.ty.sty {
 367                             ty::Int(_) => {
 368                                 let clif_ty = fx.clif_type(layout.ty).unwrap();
 369                                 if clif_ty == types::I128 {
 370                                     crate::trap::trap_unreachable_ret_value(fx, layout, "i128 neg is not yet supported").load_scalar(fx)
 371                                 } else {
 372                                     let zero = fx.bcx.ins().iconst(clif_ty, 0);
 373                                     fx.bcx.ins().isub(zero, val)
 374                                 }
 375                             }
 376                             ty::Float(_) => fx.bcx.ins().fneg(val),
 377                             _ => unimplemented!("un op Neg for {:?}", layout.ty),
 378                         },
 379                     };
 380                     lval.write_cvalue(fx, CValue::by_val(res, layout));
 381                 }
 382                 Rvalue::Cast(CastKind::Pointer(PointerCast::ReifyFnPointer), operand, ty) => {
 383                     let layout = fx.layout_of(ty);
 384                     match fx
 385                         .monomorphize(&operand.ty(&fx.mir.local_decls, fx.tcx))
 386                         .sty
 387                     {
 388                         ty::FnDef(def_id, substs) => {
 389                             let func_ref = fx.get_function_ref(
 390                                 Instance::resolve(fx.tcx, ParamEnv::reveal_all(), def_id, substs)
 391                                     .unwrap(),
 392                             );
 393                             let func_addr = fx.bcx.ins().func_addr(fx.pointer_type, func_ref);
 394                             lval.write_cvalue(fx, CValue::by_val(func_addr, layout));
 395                         }
 396                         _ => bug!("Trying to ReifyFnPointer on non FnDef {:?}", ty),
 397                     }
 398                 }
 399                 Rvalue::Cast(CastKind::Pointer(PointerCast::UnsafeFnPointer), operand, ty)
 400                 | Rvalue::Cast(CastKind::Pointer(PointerCast::MutToConstPointer), operand, ty) => {
 401                     let operand = trans_operand(fx, operand);
 402                     let layout = fx.layout_of(ty);
 403                     lval.write_cvalue(fx, operand.unchecked_cast_to(layout));
 404                 }
 405                 Rvalue::Cast(CastKind::Misc, operand, to_ty) => {
 406                     let operand = trans_operand(fx, operand);
 407                     let from_ty = operand.layout().ty;
 408
 409                     fn is_fat_ptr<'a, 'tcx: 'a>(fx: &FunctionCx<'a, 'tcx, impl Backend>, ty: Ty<'tcx>) -> bool {
 410                         ty
 411                             .builtin_deref(true)
 412                             .map(|ty::TypeAndMut {ty: pointee_ty, mutbl: _ }| fx.layout_of(pointee_ty).is_unsized())
 413                             .unwrap_or(false)
 414                     }
 415
 416                     if is_fat_ptr(fx, from_ty) {
 417                         if is_fat_ptr(fx, to_ty) {
 418                             // fat-ptr -> fat-ptr
 419                             lval.write_cvalue(fx, operand.unchecked_cast_to(dest_layout));
 420                         } else {
 421                             // fat-ptr -> thin-ptr
 422                             let (ptr, _extra) = operand.load_scalar_pair(fx);
 423                             lval.write_cvalue(fx, CValue::by_val(ptr, dest_layout))
 424                         }
 425                     } else if let ty::Adt(adt_def, _substs) = from_ty.sty {
 426                         // enum -> discriminant value
 427                         assert!(adt_def.is_enum());
 428                         match to_ty.sty {
 429                             ty::Uint(_) | ty::Int(_) => {},
 430                             _ => unreachable!("cast adt {} -> {}", from_ty, to_ty),
 431                         }
 432
 433                         // FIXME avoid forcing to stack
 434                         let place =
 435                             CPlace::for_addr(operand.force_stack(fx), operand.layout());
 436                         let discr = trans_get_discriminant(fx, place, fx.layout_of(to_ty));
 437                         lval.write_cvalue(fx, discr);
 438                     } else {
 439                         let to_clif_ty = fx.clif_type(to_ty).unwrap();
 440                         let from = operand.load_scalar(fx);
 441
 442                         let signed = match from_ty.sty {
 443                             ty::Ref(..) | ty::RawPtr(..) | ty::FnPtr(..) | ty::Char | ty::Uint(..) | ty::Bool => false,
 444                             ty::Int(..) => true,
 445                             ty::Float(..) => false, // `signed` is unused for floats
 446                             _ => panic!("{}", from_ty),
 447                         };
 448
 449                         let res = clif_int_or_float_cast(fx, from, to_clif_ty, signed);
 450                         lval.write_cvalue(fx, CValue::by_val(res, dest_layout));
 451                     }
 452                 }
 453                 Rvalue::Cast(CastKind::Pointer(PointerCast::ClosureFnPointer(_)), operand, _ty) => {
 454                     let operand = trans_operand(fx, operand);
 455                     match operand.layout().ty.sty {
 456                         ty::Closure(def_id, substs) => {
 457                             let instance = Instance::resolve_closure(
 458                                 fx.tcx,
 459                                 def_id,
 460                                 substs,
 461                                 ty::ClosureKind::FnOnce,
 462                             );
 463                             let func_ref = fx.get_function_ref(instance);
 464                             let func_addr = fx.bcx.ins().func_addr(fx.pointer_type, func_ref);
 465                             lval.write_cvalue(fx, CValue::by_val(func_addr, lval.layout()));
 466                         }
 467                         _ => {
 468                             bug!("{} cannot be cast to a fn ptr", operand.layout().ty)
 469                         }
 470                     }
 471                 }
 472                 Rvalue::Cast(CastKind::Pointer(PointerCast::Unsize), operand, _ty) => {
 473                     let operand = trans_operand(fx, operand);
 474                     operand.unsize_value(fx, lval);
 475                 }
 476                 Rvalue::Discriminant(place) => {
 477                     let place = trans_place(fx, place);
 478                     let discr = trans_get_discriminant(fx, place, dest_layout);
 479                     lval.write_cvalue(fx, discr);
 480                 }
 481                 Rvalue::Repeat(operand, times) => {
 482                     let operand = trans_operand(fx, operand);
 483                     for i in 0..*times {
 484                         let index = fx.bcx.ins().iconst(fx.pointer_type, i as i64);
 485                         let to = lval.place_index(fx, index);
 486                         to.write_cvalue(fx, operand);
 487                     }
 488                 }
 489                 Rvalue::Len(place) => {
 490                     let place = trans_place(fx, place);
 491                     let usize_layout = fx.layout_of(fx.tcx.types.usize);
 492                     let len = codegen_array_len(fx, place);
 493                     lval.write_cvalue(fx, CValue::by_val(len, usize_layout));
 494                 }
 495                 Rvalue::NullaryOp(NullOp::Box, content_ty) => {
 496                     use rustc::middle::lang_items::ExchangeMallocFnLangItem;
 497
 498                     let usize_type = fx.clif_type(fx.tcx.types.usize).unwrap();
 499                     let layout = fx.layout_of(content_ty);
 500                     let llsize = fx.bcx.ins().iconst(usize_type, layout.size.bytes() as i64);
 501                     let llalign = fx
 502                         .bcx
 503                         .ins()
 504                         .iconst(usize_type, layout.align.abi.bytes() as i64);
 505                     let box_layout = fx.layout_of(fx.tcx.mk_box(content_ty));
 506
 507                     // Allocate space:
 508                     let def_id = match fx.tcx.lang_items().require(ExchangeMallocFnLangItem) {
 509                         Ok(id) => id,
 510                         Err(s) => {
 511                             fx.tcx
 512                                 .sess
 513                                 .fatal(&format!("allocation of `{}` {}", box_layout.ty, s));
 514                         }
 515                     };
 516                     let instance = ty::Instance::mono(fx.tcx, def_id);
 517                     let func_ref = fx.get_function_ref(instance);
 518                     let call = fx.bcx.ins().call(func_ref, &[llsize, llalign]);
 519                     let ptr = fx.bcx.inst_results(call)[0];
 520                     lval.write_cvalue(fx, CValue::by_val(ptr, box_layout));
 521                 }
 522                 Rvalue::NullaryOp(NullOp::SizeOf, ty) => {
 523                     assert!(lval
 524                         .layout()
 525                         .ty
 526                         .is_sized(fx.tcx.at(DUMMY_SP), ParamEnv::reveal_all()));
 527                     let ty_size = fx.layout_of(ty).size.bytes();
 528                     let val = CValue::const_val(fx, fx.tcx.types.usize, ty_size.into());
 529                     lval.write_cvalue(fx, val);
 530                 }
 531                 Rvalue::Aggregate(kind, operands) => match **kind {
 532                     AggregateKind::Array(_ty) => {
 533                         for (i, operand) in operands.into_iter().enumerate() {
 534                             let operand = trans_operand(fx, operand);
 535                             let index = fx.bcx.ins().iconst(fx.pointer_type, i as i64);
 536                             let to = lval.place_index(fx, index);
 537                             to.write_cvalue(fx, operand);
 538                         }
 539                     }
 540                     _ => unimpl!("shouldn't exist at trans {:?}", rval),
 541                 },
 542             }
 543         }
 544         StatementKind::StorageLive(_)
 545         | StatementKind::StorageDead(_)
 546         | StatementKind::Nop
 547         | StatementKind::FakeRead(..)
 548         | StatementKind::Retag { .. }
 549         | StatementKind::AscribeUserType(..) => {}
 550
 551         StatementKind::InlineAsm(asm) => {
 552             use syntax::ast::Name;
 553             let InlineAsm { asm, outputs: _, inputs: _ } = &**asm;
 554             let rustc::hir::InlineAsm {
 555                 asm: asm_code, // Name
 556                 outputs, // Vec<Name>
 557                 inputs, // Vec<Name>
 558                 clobbers, // Vec<Name>
 559                 volatile, // bool
 560                 alignstack, // bool
 561                 dialect: _, // syntax::ast::AsmDialect
 562                 asm_str_style: _,
 563                 ctxt: _,
 564             } = asm;
 565             match &*asm_code.as_str() {
 566                 "cpuid" | "cpuid\n" => {
 567                     assert_eq!(inputs, &[Name::intern("{eax}"), Name::intern("{ecx}")]);
 568
 569                     assert_eq!(outputs.len(), 4);
 570                     for (i, c) in (&["={eax}", "={ebx}", "={ecx}", "={edx}"]).iter().enumerate() {
 571                         assert_eq!(&outputs[i].constraint.as_str(), c);
 572                         assert!(!outputs[i].is_rw);
 573                         assert!(!outputs[i].is_indirect);
 574                     }
 575
 576                     assert_eq!(clobbers, &[Name::intern("rbx")]);
 577
 578                     assert!(!volatile);
 579                     assert!(!alignstack);
 580
 581                     crate::trap::trap_unimplemented(fx, "__cpuid_count arch intrinsic is not supported");
 582                 }
 583                 "xgetbv" => {
 584                     assert_eq!(inputs, &[Name::intern("{ecx}")]);
 585
 586                     assert_eq!(outputs.len(), 2);
 587                     for (i, c) in (&["={eax}", "={edx}"]).iter().enumerate() {
 588                         assert_eq!(&outputs[i].constraint.as_str(), c);
 589                         assert!(!outputs[i].is_rw);
 590                         assert!(!outputs[i].is_indirect);
 591                     }
 592
 593                     assert_eq!(clobbers, &[]);
 594
 595                     assert!(!volatile);
 596                     assert!(!alignstack);
 597
 598                     crate::trap::trap_unimplemented(fx, "_xgetbv arch intrinsic is not supported");
 599                 }
 600                 _ if fx.tcx.symbol_name(fx.instance).as_str() == "__rust_probestack" => {
 601                     crate::trap::trap_unimplemented(fx, "__rust_probestack is not supported");
 602                 }
 603                 _ => unimpl!("Inline assembly is not supported"),
 604             }
 605         }
 606     }
 607 }
 608
 609 fn codegen_array_len<'a, 'tcx: 'a>(
 610     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 611     place: CPlace<'tcx>,
 612 ) -> Value {
 613     match place.layout().ty.sty {
 614         ty::Array(_elem_ty, len) => {
 615             let len = crate::constant::force_eval_const(fx, len)
 616                 .eval_usize(fx.tcx, ParamEnv::reveal_all()) as i64;
 617             fx.bcx.ins().iconst(fx.pointer_type, len)
 618         }
 619         ty::Slice(_elem_ty) => place
 620             .to_addr_maybe_unsized(fx)
 621             .1
 622             .expect("Length metadata for slice place"),
 623         _ => bug!("Rvalue::Len({:?})", place),
 624     }
 625 }
 626
 627 pub fn trans_get_discriminant<'a, 'tcx: 'a>(
 628     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 629     place: CPlace<'tcx>,
 630     dest_layout: TyLayout<'tcx>,
 631 ) -> CValue<'tcx> {
 632     let layout = place.layout();
 633
 634     if layout.abi == layout::Abi::Uninhabited {
 635         return trap_unreachable_ret_value(fx, dest_layout, "[panic] Tried to get discriminant for uninhabited type.");
 636     }
 637
 638     let (discr_scalar, discr_index, discr_kind) = match &layout.variants {
 639         layout::Variants::Single { index } => {
 640             let discr_val = layout
 641                 .ty
 642                 .ty_adt_def()
 643                 .map_or(index.as_u32() as u128, |def| {
 644                     def.discriminant_for_variant(fx.tcx, *index).val
 645                 });
 646             return CValue::const_val(fx, dest_layout.ty, discr_val);
 647         }
 648         layout::Variants::Multiple { discr, discr_index, discr_kind, variants: _ } => {
 649             (discr, *discr_index, discr_kind)
 650         }
 651     };
 652
 653     let discr = place.place_field(fx, mir::Field::new(discr_index)).to_cvalue(fx);
 654     let discr_ty = discr.layout().ty;
 655     let lldiscr = discr.load_scalar(fx);
 656     match discr_kind {
 657         layout::DiscriminantKind::Tag => {
 658             let signed = match discr_scalar.value {
 659                 layout::Int(_, signed) => signed,
 660                 _ => false,
 661             };
 662             let val = clif_intcast(fx, lldiscr, fx.clif_type(dest_layout.ty).unwrap(), signed);
 663             return CValue::by_val(val, dest_layout);
 664         }
 665         layout::DiscriminantKind::Niche {
 666             dataful_variant,
 667             ref niche_variants,
 668             niche_start,
 669         } => {
 670             let niche_llty = fx.clif_type(discr_ty).unwrap();
 671             let dest_clif_ty = fx.clif_type(dest_layout.ty).unwrap();
 672             if niche_variants.start() == niche_variants.end() {
 673                 let b = fx
 674                     .bcx
 675                     .ins()
 676                     .icmp_imm(IntCC::Equal, lldiscr, *niche_start as u64 as i64);
 677                 let if_true = fx
 678                     .bcx
 679                     .ins()
 680                     .iconst(dest_clif_ty, niche_variants.start().as_u32() as i64);
 681                 let if_false = fx
 682                     .bcx
 683                     .ins()
 684                     .iconst(dest_clif_ty, dataful_variant.as_u32() as i64);
 685                 let val = fx.bcx.ins().select(b, if_true, if_false);
 686                 return CValue::by_val(val, dest_layout);
 687             } else {
 688                 // Rebase from niche values to discriminant values.
 689                 let delta = niche_start.wrapping_sub(niche_variants.start().as_u32() as u128);
 690                 let delta = fx.bcx.ins().iconst(niche_llty, delta as u64 as i64);
 691                 let lldiscr = fx.bcx.ins().isub(lldiscr, delta);
 692                 let b = fx.bcx.ins().icmp_imm(
 693                     IntCC::UnsignedLessThanOrEqual,
 694                     lldiscr,
 695                     niche_variants.end().as_u32() as i64,
 696                 );
 697                 let if_true =
 698                     clif_intcast(fx, lldiscr, fx.clif_type(dest_layout.ty).unwrap(), false);
 699                 let if_false = fx
 700                     .bcx
 701                     .ins()
 702                     .iconst(dest_clif_ty, dataful_variant.as_u32() as i64);
 703                 let val = fx.bcx.ins().select(b, if_true, if_false);
 704                 return CValue::by_val(val, dest_layout);
 705             }
 706         }
 707     }
 708 }
 709
 710 macro_rules! binop_match {
 711     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, bug) => {
 712         bug!("binop {} on {} lhs: {:?} rhs: {:?}", stringify!($var), $bug_fmt, $lhs, $rhs)
 713     };
 714     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, icmp($cc:ident)) => {{
 715         assert_eq!($fx.tcx.types.bool, $ret_ty);
 716         let ret_layout = $fx.layout_of($ret_ty);
 717
 718         let b = $fx.bcx.ins().icmp(IntCC::$cc, $lhs, $rhs);
 719         CValue::by_val($fx.bcx.ins().bint(types::I8, b), ret_layout)
 720     }};
 721     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, fcmp($cc:ident)) => {{
 722         assert_eq!($fx.tcx.types.bool, $ret_ty);
 723         let ret_layout = $fx.layout_of($ret_ty);
 724         let b = $fx.bcx.ins().fcmp(FloatCC::$cc, $lhs, $rhs);
 725         CValue::by_val($fx.bcx.ins().bint(types::I8, b), ret_layout)
 726     }};
 727     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, custom(|| $body:expr)) => {{
 728         $body
 729     }};
 730     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, $name:ident) => {{
 731         let ret_layout = $fx.layout_of($ret_ty);
 732         CValue::by_val($fx.bcx.ins().$name($lhs, $rhs), ret_layout)
 733     }};
 734     (
 735         $fx:expr, $bin_op:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, $bug_fmt:expr;
 736         $(
 737             $var:ident ($sign:pat) $name:tt $( ( $($next:tt)* ) )? ;
 738         )*
 739     ) => {{
 740         let lhs = $lhs.load_scalar($fx);
 741         let rhs = $rhs.load_scalar($fx);
 742         match ($bin_op, $signed) {
 743             $(
 744                 (BinOp::$var, $sign) => binop_match!(@single $fx, $bug_fmt, $var, $signed, lhs, rhs, $ret_ty, $name $( ( $($next)* ) )?),
 745             )*
 746         }
 747     }}
 748 }
 749
 750 fn trans_bool_binop<'a, 'tcx: 'a>(
 751     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 752     bin_op: BinOp,
 753     lhs: CValue<'tcx>,
 754     rhs: CValue<'tcx>,
 755 ) -> CValue<'tcx> {
 756     let res = binop_match! {
 757         fx, bin_op, false, lhs, rhs, fx.tcx.types.bool, "bool";
 758         Add (_) bug;
 759         Sub (_) bug;
 760         Mul (_) bug;
 761         Div (_) bug;
 762         Rem (_) bug;
 763         BitXor (_) bxor;
 764         BitAnd (_) band;
 765         BitOr (_) bor;
 766         Shl (_) bug;
 767         Shr (_) bug;
 768
 769         Eq (_) icmp(Equal);
 770         Lt (_) icmp(UnsignedLessThan);
 771         Le (_) icmp(UnsignedLessThanOrEqual);
 772         Ne (_) icmp(NotEqual);
 773         Ge (_) icmp(UnsignedGreaterThanOrEqual);
 774         Gt (_) icmp(UnsignedGreaterThan);
 775
 776         Offset (_) bug;
 777     };
 778
 779     res
 780 }
 781
 782 pub fn trans_int_binop<'a, 'tcx: 'a>(
 783     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 784     bin_op: BinOp,
 785     lhs: CValue<'tcx>,
 786     rhs: CValue<'tcx>,
 787     out_ty: Ty<'tcx>,
 788     signed: bool,
 789 ) -> CValue<'tcx> {
 790     if bin_op != BinOp::Shl && bin_op != BinOp::Shr {
 791         assert_eq!(
 792             lhs.layout().ty,
 793             rhs.layout().ty,
 794             "int binop requires lhs and rhs of same type"
 795         );
 796     }
 797
 798     match out_ty.sty {
 799         ty::Bool | ty::Uint(_) | ty::Int(_) => {}
 800         _ => unreachable!("Out ty {:?} is not an integer or bool", out_ty),
 801     }
 802
 803     if let Some(res) = crate::codegen_i128::maybe_codegen(fx, bin_op, false, signed, lhs, rhs, out_ty) {
 804         return res;
 805     }
 806
 807     binop_match! {
 808         fx, bin_op, signed, lhs, rhs, out_ty, "int/uint";
 809         Add (_) iadd;
 810         Sub (_) isub;
 811         Mul (_) imul;
 812         Div (false) udiv;
 813         Div (true) sdiv;
 814         Rem (false) urem;
 815         Rem (true) srem;
 816         BitXor (_) bxor;
 817         BitAnd (_) band;
 818         BitOr (_) bor;
 819         Shl (_) ishl;
 820         Shr (false) ushr;
 821         Shr (true) sshr;
 822
 823         Eq (_) icmp(Equal);
 824         Lt (false) icmp(UnsignedLessThan);
 825         Lt (true) icmp(SignedLessThan);
 826         Le (false) icmp(UnsignedLessThanOrEqual);
 827         Le (true) icmp(SignedLessThanOrEqual);
 828         Ne (_) icmp(NotEqual);
 829         Ge (false) icmp(UnsignedGreaterThanOrEqual);
 830         Ge (true) icmp(SignedGreaterThanOrEqual);
 831         Gt (false) icmp(UnsignedGreaterThan);
 832         Gt (true) icmp(SignedGreaterThan);
 833
 834         Offset (_) bug;
 835     }
 836 }
 837
 838 pub fn trans_checked_int_binop<'a, 'tcx: 'a>(
 839     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 840     bin_op: BinOp,
 841     in_lhs: CValue<'tcx>,
 842     in_rhs: CValue<'tcx>,
 843     out_ty: Ty<'tcx>,
 844     signed: bool,
 845 ) -> CValue<'tcx> {
 846     if !fx.tcx.sess.overflow_checks() {
 847         let val = trans_int_binop(fx, bin_op, in_lhs, in_rhs, in_lhs.layout().ty, signed).load_scalar(fx);
 848         let is_overflow = fx.bcx.ins().iconst(types::I8, 0);
 849         return CValue::by_val_pair(val, is_overflow, fx.layout_of(out_ty));
 850     }
 851
 852     if bin_op != BinOp::Shl && bin_op != BinOp::Shr {
 853         assert_eq!(
 854             in_lhs.layout().ty,
 855             in_rhs.layout().ty,
 856             "checked int binop requires lhs and rhs of same type"
 857         );
 858     }
 859
 860     let lhs = in_lhs.load_scalar(fx);
 861     let rhs = in_rhs.load_scalar(fx);
 862
 863     if let Some(res) = crate::codegen_i128::maybe_codegen(fx, bin_op, true, signed, in_lhs, in_rhs, out_ty) {
 864         return res;
 865     }
 866
 867     let (res, has_overflow) = match bin_op {
 868         BinOp::Add => {
 869             /*let (val, c_out) = fx.bcx.ins().iadd_cout(lhs, rhs);
 870             (val, c_out)*/
 871             // FIXME(CraneStation/cranelift#849) legalize iadd_cout for i8 and i16
 872             let val = fx.bcx.ins().iadd(lhs, rhs);
 873             let has_overflow = if !signed {
 874                 fx.bcx.ins().icmp(IntCC::UnsignedLessThan, val, lhs)
 875             } else {
 876                 let rhs_is_negative = fx.bcx.ins().icmp_imm(IntCC::SignedLessThan, rhs, 0);
 877                 let slt = fx.bcx.ins().icmp(IntCC::SignedLessThan, val, lhs);
 878                 fx.bcx.ins().bxor(rhs_is_negative, slt)
 879             };
 880             (val, has_overflow)
 881         }
 882         BinOp::Sub => {
 883             /*let (val, b_out) = fx.bcx.ins().isub_bout(lhs, rhs);
 884             (val, b_out)*/
 885             // FIXME(CraneStation/cranelift#849) legalize isub_bout for i8 and i16
 886             let val = fx.bcx.ins().isub(lhs, rhs);
 887             let has_overflow = if !signed {
 888                 fx.bcx.ins().icmp(IntCC::UnsignedGreaterThan, val, lhs)
 889             } else {
 890                 let rhs_is_negative = fx.bcx.ins().icmp_imm(IntCC::SignedLessThan, rhs, 0);
 891                 let sgt = fx.bcx.ins().icmp(IntCC::SignedGreaterThan, val, lhs);
 892                 fx.bcx.ins().bxor(rhs_is_negative, sgt)
 893             };
 894             (val, has_overflow)
 895         }
 896         BinOp::Mul => {
 897             let val = fx.bcx.ins().imul(lhs, rhs);
 898             /*let val_hi = if !signed {
 899                 fx.bcx.ins().umulhi(lhs, rhs)
 900             } else {
 901                 fx.bcx.ins().smulhi(lhs, rhs)
 902             };
 903             let has_overflow = fx.bcx.ins().icmp_imm(IntCC::NotEqual, val_hi, 0);*/
 904             // TODO: check for overflow
 905             let has_overflow = fx.bcx.ins().bconst(types::B1, false);
 906             (val, has_overflow)
 907         }
 908         BinOp::Shl => {
 909             let val = fx.bcx.ins().ishl(lhs, rhs);
 910             // TODO: check for overflow
 911             let has_overflow = fx.bcx.ins().bconst(types::B1, false);
 912             (val, has_overflow)
 913         }
 914         BinOp::Shr => {
 915             let val = if !signed {
 916                 fx.bcx.ins().ushr(lhs, rhs)
 917             } else {
 918                 fx.bcx.ins().sshr(lhs, rhs)
 919             };
 920             // TODO: check for overflow
 921             let has_overflow = fx.bcx.ins().bconst(types::B1, false);
 922             (val, has_overflow)
 923         }
 924         _ => bug!(
 925             "binop {:?} on checked int/uint lhs: {:?} rhs: {:?}",
 926             bin_op,
 927             in_lhs,
 928             in_rhs
 929         ),
 930     };
 931
 932     let has_overflow = fx.bcx.ins().bint(types::I8, has_overflow);
 933     let out_place = CPlace::new_stack_slot(fx, out_ty);
 934     let out_layout = out_place.layout();
 935     out_place.write_cvalue(fx, CValue::by_val_pair(res, has_overflow, out_layout));
 936
 937     out_place.to_cvalue(fx)
 938 }
 939
 940 fn trans_float_binop<'a, 'tcx: 'a>(
 941     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 942     bin_op: BinOp,
 943     lhs: CValue<'tcx>,
 944     rhs: CValue<'tcx>,
 945     ty: Ty<'tcx>,
 946 ) -> CValue<'tcx> {
 947     let res = binop_match! {
 948         fx, bin_op, false, lhs, rhs, ty, "float";
 949         Add (_) fadd;
 950         Sub (_) fsub;
 951         Mul (_) fmul;
 952         Div (_) fdiv;
 953         Rem (_) custom(|| {
 954             assert_eq!(lhs.layout().ty, ty);
 955             assert_eq!(rhs.layout().ty, ty);
 956             match ty.sty {
 957                 ty::Float(FloatTy::F32) => fx.easy_call("fmodf", &[lhs, rhs], ty),
 958                 ty::Float(FloatTy::F64) => fx.easy_call("fmod", &[lhs, rhs], ty),
 959                 _ => bug!(),
 960             }
 961         });
 962         BitXor (_) bxor;
 963         BitAnd (_) band;
 964         BitOr (_) bor;
 965         Shl (_) bug;
 966         Shr (_) bug;
 967
 968         Eq (_) fcmp(Equal);
 969         Lt (_) fcmp(LessThan);
 970         Le (_) fcmp(LessThanOrEqual);
 971         Ne (_) fcmp(NotEqual);
 972         Ge (_) fcmp(GreaterThanOrEqual);
 973         Gt (_) fcmp(GreaterThan);
 974
 975         Offset (_) bug;
 976     };
 977
 978     res
 979 }
 980
 981 fn trans_char_binop<'a, 'tcx: 'a>(
 982     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 983     bin_op: BinOp,
 984     lhs: CValue<'tcx>,
 985     rhs: CValue<'tcx>,
 986     ty: Ty<'tcx>,
 987 ) -> CValue<'tcx> {
 988     let res = binop_match! {
 989         fx, bin_op, false, lhs, rhs, ty, "char";
 990         Add (_) bug;
 991         Sub (_) bug;
 992         Mul (_) bug;
 993         Div (_) bug;
 994         Rem (_) bug;
 995         BitXor (_) bug;
 996         BitAnd (_) bug;
 997         BitOr (_) bug;
 998         Shl (_) bug;
 999         Shr (_) bug;
1000
1001         Eq (_) icmp(Equal);
1002         Lt (_) icmp(UnsignedLessThan);
1003         Le (_) icmp(UnsignedLessThanOrEqual);
1004         Ne (_) icmp(NotEqual);
1005         Ge (_) icmp(UnsignedGreaterThanOrEqual);
1006         Gt (_) icmp(UnsignedGreaterThan);
1007
1008         Offset (_) bug;
1009     };
1010
1011     res
1012 }
1013
1014 fn trans_ptr_binop<'a, 'tcx: 'a>(
1015     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
1016     bin_op: BinOp,
1017     lhs: CValue<'tcx>,
1018     rhs: CValue<'tcx>,
1019     ret_ty: Ty<'tcx>,
1020 ) -> CValue<'tcx> {
1021     let not_fat = match lhs.layout().ty.sty {
1022         ty::RawPtr(TypeAndMut { ty, mutbl: _ }) => {
1023             ty.is_sized(fx.tcx.at(DUMMY_SP), ParamEnv::reveal_all())
1024         }
1025         ty::FnPtr(..) => true,
1026         _ => bug!("trans_ptr_binop on non ptr"),
1027     };
1028     if not_fat {
1029         if let BinOp::Offset = bin_op {
1030             let (base, offset) = (lhs, rhs.load_scalar(fx));
1031             let pointee_ty = base.layout().ty.builtin_deref(true).unwrap().ty;
1032             let pointee_size = fx.layout_of(pointee_ty).size.bytes();
1033             let ptr_diff = fx.bcx.ins().imul_imm(offset, pointee_size as i64);
1034             let base_val = base.load_scalar(fx);
1035             let res = fx.bcx.ins().iadd(base_val, ptr_diff);
1036             return CValue::by_val(res, base.layout());
1037         }
1038
1039         binop_match! {
1040             fx, bin_op, false, lhs, rhs, ret_ty, "ptr";
1041             Add (_) bug;
1042             Sub (_) bug;
1043             Mul (_) bug;
1044             Div (_) bug;
1045             Rem (_) bug;
1046             BitXor (_) bug;
1047             BitAnd (_) bug;
1048             BitOr (_) bug;
1049             Shl (_) bug;
1050             Shr (_) bug;
1051
1052             Eq (_) icmp(Equal);
1053             Lt (_) icmp(UnsignedLessThan);
1054             Le (_) icmp(UnsignedLessThanOrEqual);
1055             Ne (_) icmp(NotEqual);
1056             Ge (_) icmp(UnsignedGreaterThanOrEqual);
1057             Gt (_) icmp(UnsignedGreaterThan);
1058
1059             Offset (_) bug; // Handled above
1060         }
1061     } else {
1062         let (lhs_ptr, lhs_extra) = lhs.load_scalar_pair(fx);
1063         let (rhs_ptr, rhs_extra) = rhs.load_scalar_pair(fx);
1064
1065         let res = match bin_op {
1066             BinOp::Eq => {
1067                 let ptr_eq = fx.bcx.ins().icmp(IntCC::Equal, lhs_ptr, rhs_ptr);
1068                 let extra_eq = fx.bcx.ins().icmp(IntCC::Equal, lhs_extra, rhs_extra);
1069                 fx.bcx.ins().band(ptr_eq, extra_eq)
1070             }
1071             BinOp::Ne => {
1072                 let ptr_ne = fx.bcx.ins().icmp(IntCC::NotEqual, lhs_ptr, rhs_ptr);
1073                 let extra_ne = fx.bcx.ins().icmp(IntCC::NotEqual, lhs_extra, rhs_extra);
1074                 fx.bcx.ins().bor(ptr_ne, extra_ne)
1075             }
1076             BinOp::Lt | BinOp::Le | BinOp::Ge | BinOp::Gt => {
1077                 let ptr_eq = fx.bcx.ins().icmp(IntCC::Equal, lhs_ptr, rhs_ptr);
1078
1079                 let ptr_cmp = fx.bcx.ins().icmp(match bin_op {
1080                     BinOp::Lt => IntCC::UnsignedLessThan,
1081                     BinOp::Le => IntCC::UnsignedLessThanOrEqual,
1082                     BinOp::Ge => IntCC::UnsignedGreaterThanOrEqual,
1083                     BinOp::Gt => IntCC::UnsignedGreaterThan,
1084                     _ => unreachable!(),
1085                 }, lhs_ptr, rhs_ptr);
1086
1087                 let extra_cmp = fx.bcx.ins().icmp(match bin_op {
1088                     BinOp::Lt => IntCC::UnsignedLessThan,
1089                     BinOp::Le => IntCC::UnsignedLessThanOrEqual,
1090                     BinOp::Ge => IntCC::UnsignedGreaterThanOrEqual,
1091                     BinOp::Gt => IntCC::UnsignedGreaterThan,
1092                     _ => unreachable!(),
1093                 }, lhs_extra, rhs_extra);
1094
1095                 fx.bcx.ins().select(ptr_eq, extra_cmp, ptr_cmp)
1096             }
1097             _ => panic!("bin_op {:?} on ptr", bin_op),
1098         };
1099
1100         assert_eq!(fx.tcx.types.bool, ret_ty);
1101         let ret_layout = fx.layout_of(ret_ty);
1102         CValue::by_val(fx.bcx.ins().bint(types::I8, res), ret_layout)
1103     }
1104 }
1105
1106 pub fn trans_place<'a, 'tcx: 'a>(
1107     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
1108     place: &Place<'tcx>,
1109 ) -> CPlace<'tcx> {
1110     let base = match &place.base {
1111         PlaceBase::Local(local) => fx.get_local_place(*local),
1112         PlaceBase::Static(static_) => match static_.kind {
1113             StaticKind::Static(def_id) => {
1114                 crate::constant::codegen_static_ref(fx, def_id, static_.ty)
1115             }
1116             StaticKind::Promoted(promoted) => {
1117                 crate::constant::trans_promoted(fx, promoted, static_.ty)
1118             }
1119         }
1120     };
1121
1122     trans_place_projection(fx, base, &place.projection)
1123 }
1124
1125 pub fn trans_place_projection<'a, 'tcx: 'a>(
1126     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
1127     base: CPlace<'tcx>,
1128     projection: &Option<Box<Projection<'tcx>>>,
1129 ) -> CPlace<'tcx> {
1130     let projection = if let Some(projection) = projection {
1131         projection
1132     } else {
1133         return base;
1134     };
1135
1136     let base = trans_place_projection(fx, base, &projection.base);
1137
1138     match projection.elem {
1139         ProjectionElem::Deref => base.place_deref(fx),
1140         ProjectionElem::Field(field, _ty) => base.place_field(fx, field),
1141         ProjectionElem::Index(local) => {
1142             let index = fx.get_local_place(local).to_cvalue(fx).load_scalar(fx);
1143             base.place_index(fx, index)
1144         }
1145         ProjectionElem::ConstantIndex {
1146             offset,
1147             min_length: _,
1148             from_end,
1149         } => {
1150             let index = if !from_end {
1151                 fx.bcx.ins().iconst(fx.pointer_type, offset as i64)
1152             } else {
1153                 let len = codegen_array_len(fx, base);
1154                 fx.bcx.ins().iadd_imm(len, -(offset as i64))
1155             };
1156             base.place_index(fx, index)
1157         }
1158         ProjectionElem::Subslice { from, to } => {
1159             // These indices are generated by slice patterns.
1160             // slice[from:-to] in Python terms.
1161
1162             match base.layout().ty.sty {
1163                 ty::Array(elem_ty, len) => {
1164                     let elem_layout = fx.layout_of(elem_ty);
1165                     let ptr = base.to_addr(fx);
1166                     let len = crate::constant::force_eval_const(fx, len)
1167                         .eval_usize(fx.tcx, ParamEnv::reveal_all());
1168                     CPlace::for_addr(
1169                         fx.bcx.ins().iadd_imm(ptr, elem_layout.size.bytes() as i64 * from as i64),
1170                         fx.layout_of(fx.tcx.mk_array(elem_ty, len - from as u64 - to as u64)),
1171                     )
1172                 }
1173                 ty::Slice(elem_ty) => {
1174                     let elem_layout = fx.layout_of(elem_ty);
1175                     let (ptr, len) = base.to_addr_maybe_unsized(fx);
1176                     let len = len.unwrap();
1177                     CPlace::for_addr_with_extra(
1178                         fx.bcx.ins().iadd_imm(ptr, elem_layout.size.bytes() as i64 * from as i64),
1179                         fx.bcx.ins().iadd_imm(len, -(from as i64 + to as i64)),
1180                         base.layout(),
1181                     )
1182                 }
1183                 _ => unreachable!(),
1184             }
1185         }
1186         ProjectionElem::Downcast(_adt_def, variant) => base.downcast_variant(fx, variant),
1187     }
1188 }
1189
1190 pub fn trans_operand<'a, 'tcx>(
1191     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
1192     operand: &Operand<'tcx>,
1193 ) -> CValue<'tcx> {
1194     match operand {
1195         Operand::Move(place) | Operand::Copy(place) => {
1196             let cplace = trans_place(fx, place);
1197             cplace.to_cvalue(fx)
1198         }
1199         Operand::Constant(const_) => crate::constant::trans_constant(fx, const_),
1200     }
1201 }