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     // Check fn sig for u128 and i128 and replace those functions with a trap.
  15     {
  16         // FIXME implement u128 and i128 support
  17
  18         // Check sig for u128 and i128
  19         let fn_sig = tcx.normalize_erasing_late_bound_regions(ParamEnv::reveal_all(), &instance.fn_sig(tcx));
  20
  21         struct UI128Visitor<'tcx>(TyCtxt<'tcx>, bool);
  22
  23         impl<'tcx> rustc::ty::fold::TypeVisitor<'tcx> for UI128Visitor<'tcx> {
  24             fn visit_ty(&mut self, t: Ty<'tcx>) -> bool {
  25                 if t.sty == self.0.types.u128.sty || t.sty == self.0.types.i128.sty {
  26                     self.1 = true;
  27                     return false; // stop visiting
  28                 }
  29
  30                 t.super_visit_with(self)
  31             }
  32         }
  33
  34         let mut visitor = UI128Visitor(tcx, false);
  35         fn_sig.visit_with(&mut visitor);
  36
  37         //If found replace function with a trap.
  38         if visitor.1 {
  39             tcx.sess.warn("u128 and i128 are not yet supported. \
  40             Functions using these as args will be replaced with a trap.");
  41
  42             // Declare function with fake signature
  43             let sig = Signature {
  44                 params: vec![AbiParam::new(types::INVALID)],
  45                 returns: vec![],
  46                 call_conv: CallConv::Fast,
  47             };
  48             let name = tcx.symbol_name(instance).as_str();
  49             let func_id = cx.module.declare_function(&*name, linkage, &sig).unwrap();
  50
  51             // Create trapping function
  52             let mut func = Function::with_name_signature(ExternalName::user(0, 0), sig);
  53             let mut func_ctx = FunctionBuilderContext::new();
  54             let mut bcx = FunctionBuilder::new(&mut func, &mut func_ctx);
  55             let start_ebb = bcx.create_ebb();
  56             bcx.append_ebb_params_for_function_params(start_ebb);
  57             bcx.switch_to_block(start_ebb);
  58
  59             let mut fx = FunctionCx {
  60                 tcx,
  61                 module: cx.module,
  62                 pointer_type: pointer_ty(tcx),
  63
  64                 instance,
  65                 mir,
  66
  67                 bcx,
  68                 ebb_map: HashMap::new(),
  69                 local_map: HashMap::new(),
  70
  71                 clif_comments: crate::pretty_clif::CommentWriter::new(tcx, instance),
  72                 constants: &mut cx.ccx,
  73                 caches: &mut cx.caches,
  74                 source_info_set: indexmap::IndexSet::new(),
  75             };
  76
  77             crate::trap::trap_unreachable(&mut fx, "[unimplemented] Called function with u128 or i128 as argument.");
  78             fx.bcx.seal_all_blocks();
  79             fx.bcx.finalize();
  80
  81             // Define function
  82             cx.caches.context.func = func;
  83             cx.module
  84                 .define_function(func_id, &mut cx.caches.context)
  85                 .unwrap();
  86             cx.caches.context.clear();
  87             return;
  88         }
  89     }
  90
  91     // Declare function
  92     let (name, sig) = get_function_name_and_sig(tcx, instance, false);
  93     let func_id = cx.module.declare_function(&name, linkage, &sig).unwrap();
  94     let mut debug_context = cx
  95         .debug_context
  96         .as_mut()
  97         .map(|debug_context| FunctionDebugContext::new(tcx, debug_context, mir, &name, &sig));
  98
  99     // Make FunctionBuilder
 100     let mut func = Function::with_name_signature(ExternalName::user(0, 0), sig);
 101     let mut func_ctx = FunctionBuilderContext::new();
 102     let mut bcx = FunctionBuilder::new(&mut func, &mut func_ctx);
 103
 104     // Predefine ebb's
 105     let start_ebb = bcx.create_ebb();
 106     let mut ebb_map: HashMap<BasicBlock, Ebb> = HashMap::new();
 107     for (bb, _bb_data) in mir.basic_blocks().iter_enumerated() {
 108         ebb_map.insert(bb, bcx.create_ebb());
 109     }
 110
 111     // Make FunctionCx
 112     let pointer_type = cx.module.target_config().pointer_type();
 113     let clif_comments = crate::pretty_clif::CommentWriter::new(tcx, instance);
 114
 115     let mut fx = FunctionCx {
 116         tcx,
 117         module: cx.module,
 118         pointer_type,
 119
 120         instance,
 121         mir,
 122
 123         bcx,
 124         ebb_map,
 125         local_map: HashMap::new(),
 126
 127         clif_comments,
 128         constants: &mut cx.ccx,
 129         caches: &mut cx.caches,
 130         source_info_set: indexmap::IndexSet::new(),
 131     };
 132
 133     with_unimpl_span(fx.mir.span, || {
 134         crate::abi::codegen_fn_prelude(&mut fx, start_ebb);
 135         codegen_fn_content(&mut fx);
 136     });
 137
 138     // Recover all necessary data from fx, before accessing func will prevent future access to it.
 139     let instance = fx.instance;
 140     let clif_comments = fx.clif_comments;
 141     let source_info_set = fx.source_info_set;
 142
 143     #[cfg(debug_assertions)]
 144     crate::pretty_clif::write_clif_file(cx.tcx, "unopt", instance, &func, &clif_comments, None);
 145
 146     // Verify function
 147     verify_func(tcx, &clif_comments, &func);
 148
 149     // Define function
 150     let context = &mut cx.caches.context;
 151     context.func = func;
 152     cx.module
 153         .define_function(func_id, context)
 154         .unwrap();
 155
 156     let value_ranges = context.build_value_labels_ranges(cx.module.isa()).expect("value location ranges");
 157
 158     // Write optimized function to file for debugging
 159     #[cfg(debug_assertions)]
 160     crate::pretty_clif::write_clif_file(cx.tcx, "opt", instance, &context.func, &clif_comments, Some(&value_ranges));
 161
 162     // Define debuginfo for function
 163     let isa = cx.module.isa();
 164     debug_context
 165         .as_mut()
 166         .map(|x| x.define(tcx, context, isa, &source_info_set));
 167
 168     // Clear context to make it usable for the next function
 169     context.clear();
 170 }
 171
 172 fn verify_func(tcx: TyCtxt, writer: &crate::pretty_clif::CommentWriter, func: &Function) {
 173     let flags = settings::Flags::new(settings::builder());
 174     match ::cranelift::codegen::verify_function(&func, &flags) {
 175         Ok(_) => {}
 176         Err(err) => {
 177             tcx.sess.err(&format!("{:?}", err));
 178             let pretty_error = ::cranelift::codegen::print_errors::pretty_verifier_error(
 179                 &func,
 180                 None,
 181                 Some(Box::new(writer)),
 182                 err,
 183             );
 184             tcx.sess
 185                 .fatal(&format!("cranelift verify error:\n{}", pretty_error));
 186         }
 187     }
 188 }
 189
 190 fn codegen_fn_content<'a, 'tcx: 'a>(fx: &mut FunctionCx<'a, 'tcx, impl Backend>) {
 191     for (bb, bb_data) in fx.mir.basic_blocks().iter_enumerated() {
 192         if bb_data.is_cleanup {
 193             // Unwinding after panicking is not supported
 194             continue;
 195         }
 196
 197         let ebb = fx.get_ebb(bb);
 198         fx.bcx.switch_to_block(ebb);
 199
 200         fx.bcx.ins().nop();
 201         for stmt in &bb_data.statements {
 202             fx.set_debug_loc(stmt.source_info);
 203             trans_stmt(fx, ebb, stmt);
 204         }
 205
 206         #[cfg(debug_assertions)]
 207         {
 208             let mut terminator_head = "\n".to_string();
 209             bb_data
 210                 .terminator()
 211                 .kind
 212                 .fmt_head(&mut terminator_head)
 213                 .unwrap();
 214             let inst = fx.bcx.func.layout.last_inst(ebb).unwrap();
 215             fx.add_comment(inst, terminator_head);
 216         }
 217
 218         fx.set_debug_loc(bb_data.terminator().source_info);
 219
 220         match &bb_data.terminator().kind {
 221             TerminatorKind::Goto { target } => {
 222                 let ebb = fx.get_ebb(*target);
 223                 fx.bcx.ins().jump(ebb, &[]);
 224             }
 225             TerminatorKind::Return => {
 226                 crate::abi::codegen_return(fx);
 227             }
 228             TerminatorKind::Assert {
 229                 cond,
 230                 expected,
 231                 msg,
 232                 target,
 233                 cleanup: _,
 234             } => {
 235                 let cond = trans_operand(fx, cond).load_scalar(fx);
 236                 // TODO HACK brz/brnz for i8/i16 is not yet implemented
 237                 let cond = fx.bcx.ins().uextend(types::I32, cond);
 238                 let target = fx.get_ebb(*target);
 239                 if *expected {
 240                     fx.bcx.ins().brnz(cond, target, &[]);
 241                 } else {
 242                     fx.bcx.ins().brz(cond, target, &[]);
 243                 };
 244                 trap_panic(fx, format!("[panic] Assert {:?} failed.", msg));
 245             }
 246
 247             TerminatorKind::SwitchInt {
 248                 discr,
 249                 switch_ty: _,
 250                 values,
 251                 targets,
 252             } => {
 253                 let discr = trans_operand(fx, discr).load_scalar(fx);
 254                 let mut switch = ::cranelift::frontend::Switch::new();
 255                 for (i, value) in values.iter().enumerate() {
 256                     let ebb = fx.get_ebb(targets[i]);
 257                     switch.set_entry(*value as u64, ebb);
 258                 }
 259                 let otherwise_ebb = fx.get_ebb(targets[targets.len() - 1]);
 260                 switch.emit(&mut fx.bcx, discr, otherwise_ebb);
 261             }
 262             TerminatorKind::Call {
 263                 func,
 264                 args,
 265                 destination,
 266                 cleanup: _,
 267                 from_hir_call: _,
 268             } => {
 269                 crate::abi::codegen_terminator_call(fx, func, args, destination);
 270             }
 271             TerminatorKind::Resume | TerminatorKind::Abort => {
 272                 trap_unreachable(fx, "[corruption] Unwinding bb reached.");
 273             }
 274             TerminatorKind::Unreachable => {
 275                 trap_unreachable(fx, "[corruption] Hit unreachable code.");
 276             }
 277             TerminatorKind::Yield { .. }
 278             | TerminatorKind::FalseEdges { .. }
 279             | TerminatorKind::FalseUnwind { .. }
 280             | TerminatorKind::DropAndReplace { .. }
 281             | TerminatorKind::GeneratorDrop => {
 282                 bug!("shouldn't exist at trans {:?}", bb_data.terminator());
 283             }
 284             TerminatorKind::Drop {
 285                 location,
 286                 target,
 287                 unwind: _,
 288             } => {
 289                 let drop_place = trans_place(fx, location);
 290                 crate::abi::codegen_drop(fx, drop_place);
 291
 292                 let target_ebb = fx.get_ebb(*target);
 293                 fx.bcx.ins().jump(target_ebb, &[]);
 294             }
 295         };
 296     }
 297
 298     fx.bcx.seal_all_blocks();
 299     fx.bcx.finalize();
 300 }
 301
 302 fn trans_stmt<'a, 'tcx: 'a>(
 303     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 304     cur_ebb: Ebb,
 305     stmt: &Statement<'tcx>,
 306 ) {
 307     let _print_guard = PrintOnPanic(|| format!("stmt {:?}", stmt));
 308
 309     fx.set_debug_loc(stmt.source_info);
 310
 311     #[cfg(debug_assertions)]
 312     match &stmt.kind {
 313         StatementKind::StorageLive(..) | StatementKind::StorageDead(..) => {} // Those are not very useful
 314         _ => {
 315             let inst = fx.bcx.func.layout.last_inst(cur_ebb).unwrap();
 316             fx.add_comment(inst, format!("{:?}", stmt));
 317         }
 318     }
 319
 320     match &stmt.kind {
 321         StatementKind::SetDiscriminant {
 322             place,
 323             variant_index,
 324         } => {
 325             let place = trans_place(fx, place);
 326             let layout = place.layout();
 327             if layout.for_variant(&*fx, *variant_index).abi == layout::Abi::Uninhabited {
 328                 return;
 329             }
 330             match layout.variants {
 331                 layout::Variants::Single { index } => {
 332                     assert_eq!(index, *variant_index);
 333                 }
 334                 layout::Variants::Multiple {
 335                     discr: _,
 336                     discr_index,
 337                     discr_kind: layout::DiscriminantKind::Tag,
 338                     variants: _,
 339                 } => {
 340                     let ptr = place.place_field(fx, mir::Field::new(discr_index));
 341                     let to = layout
 342                         .ty
 343                         .discriminant_for_variant(fx.tcx, *variant_index)
 344                         .unwrap()
 345                         .val;
 346                     let discr = CValue::const_val(fx, ptr.layout().ty, to as u64 as i64);
 347                     ptr.write_cvalue(fx, discr);
 348                 }
 349                 layout::Variants::Multiple {
 350                     discr: _,
 351                     discr_index,
 352                     discr_kind: layout::DiscriminantKind::Niche {
 353                         dataful_variant,
 354                         ref niche_variants,
 355                         niche_start,
 356                     },
 357                     variants: _,
 358                 } => {
 359                     if *variant_index != dataful_variant {
 360                         let niche = place.place_field(fx, mir::Field::new(discr_index));
 361                         //let niche_llty = niche.layout.immediate_llvm_type(bx.cx);
 362                         let niche_value =
 363                             ((variant_index.as_u32() - niche_variants.start().as_u32()) as u128)
 364                                 .wrapping_add(niche_start);
 365                         // FIXME(eddyb) Check the actual primitive type here.
 366                         let niche_llval = if niche_value == 0 {
 367                             CValue::const_val(fx, niche.layout().ty, 0)
 368                         } else {
 369                             CValue::const_val(fx, niche.layout().ty, niche_value as u64 as i64)
 370                         };
 371                         niche.write_cvalue(fx, niche_llval);
 372                     }
 373                 }
 374             }
 375         }
 376         StatementKind::Assign(to_place, rval) => {
 377             let lval = trans_place(fx, to_place);
 378             let dest_layout = lval.layout();
 379             match &**rval {
 380                 Rvalue::Use(operand) => {
 381                     let val = trans_operand(fx, operand);
 382                     lval.write_cvalue(fx, val);
 383                 }
 384                 Rvalue::Ref(_, _, place) => {
 385                     let place = trans_place(fx, place);
 386                     place.write_place_ref(fx, lval);
 387                 }
 388                 Rvalue::BinaryOp(bin_op, lhs, rhs) => {
 389                     let ty = fx.monomorphize(&lhs.ty(fx.mir, fx.tcx));
 390                     let lhs = trans_operand(fx, lhs);
 391                     let rhs = trans_operand(fx, rhs);
 392
 393                     let res = match ty.sty {
 394                         ty::Bool => trans_bool_binop(fx, *bin_op, lhs, rhs, lval.layout().ty),
 395                         ty::Uint(_) => {
 396                             trans_int_binop(fx, *bin_op, lhs, rhs, lval.layout().ty, false)
 397                         }
 398                         ty::Int(_) => {
 399                             trans_int_binop(fx, *bin_op, lhs, rhs, lval.layout().ty, true)
 400                         }
 401                         ty::Float(_) => trans_float_binop(fx, *bin_op, lhs, rhs, lval.layout().ty),
 402                         ty::Char => trans_char_binop(fx, *bin_op, lhs, rhs, lval.layout().ty),
 403                         ty::RawPtr(..) => trans_ptr_binop(fx, *bin_op, lhs, rhs, lval.layout().ty),
 404                         ty::FnPtr(..) => trans_ptr_binop(fx, *bin_op, lhs, rhs, lval.layout().ty),
 405                         _ => unimplemented!("binop {:?} for {:?}", bin_op, ty),
 406                     };
 407                     lval.write_cvalue(fx, res);
 408                 }
 409                 Rvalue::CheckedBinaryOp(bin_op, lhs, rhs) => {
 410                     let ty = fx.monomorphize(&lhs.ty(fx.mir, fx.tcx));
 411                     let lhs = trans_operand(fx, lhs);
 412                     let rhs = trans_operand(fx, rhs);
 413
 414                     let res = match ty.sty {
 415                         ty::Uint(_) => {
 416                             trans_checked_int_binop(fx, *bin_op, lhs, rhs, lval.layout().ty, false)
 417                         }
 418                         ty::Int(_) => {
 419                             trans_checked_int_binop(fx, *bin_op, lhs, rhs, lval.layout().ty, true)
 420                         }
 421                         _ => unimplemented!("checked binop {:?} for {:?}", bin_op, ty),
 422                     };
 423                     lval.write_cvalue(fx, res);
 424                 }
 425                 Rvalue::UnaryOp(un_op, operand) => {
 426                     let operand = trans_operand(fx, operand);
 427                     let layout = operand.layout();
 428                     let val = operand.load_scalar(fx);
 429                     let res = match un_op {
 430                         UnOp::Not => {
 431                             match layout.ty.sty {
 432                                 ty::Bool => {
 433                                     let val = fx.bcx.ins().uextend(types::I32, val); // WORKAROUND for CraneStation/cranelift#466
 434                                     let res = fx.bcx.ins().icmp_imm(IntCC::Equal, val, 0);
 435                                     fx.bcx.ins().bint(types::I8, res)
 436                                 }
 437                                 ty::Uint(_) | ty::Int(_) => fx.bcx.ins().bnot(val),
 438                                 _ => unimplemented!("un op Not for {:?}", layout.ty),
 439                             }
 440                         }
 441                         UnOp::Neg => match layout.ty.sty {
 442                             ty::Int(_) => {
 443                                 let clif_ty = fx.clif_type(layout.ty).unwrap();
 444                                 let zero = fx.bcx.ins().iconst(clif_ty, 0);
 445                                 fx.bcx.ins().isub(zero, val)
 446                             }
 447                             ty::Float(_) => fx.bcx.ins().fneg(val),
 448                             _ => unimplemented!("un op Neg for {:?}", layout.ty),
 449                         },
 450                     };
 451                     lval.write_cvalue(fx, CValue::by_val(res, layout));
 452                 }
 453                 Rvalue::Cast(CastKind::Pointer(PointerCast::ReifyFnPointer), operand, ty) => {
 454                     let layout = fx.layout_of(ty);
 455                     match fx
 456                         .monomorphize(&operand.ty(&fx.mir.local_decls, fx.tcx))
 457                         .sty
 458                     {
 459                         ty::FnDef(def_id, substs) => {
 460                             let func_ref = fx.get_function_ref(
 461                                 Instance::resolve(fx.tcx, ParamEnv::reveal_all(), def_id, substs)
 462                                     .unwrap(),
 463                             );
 464                             let func_addr = fx.bcx.ins().func_addr(fx.pointer_type, func_ref);
 465                             lval.write_cvalue(fx, CValue::by_val(func_addr, layout));
 466                         }
 467                         _ => bug!("Trying to ReifyFnPointer on non FnDef {:?}", ty),
 468                     }
 469                 }
 470                 Rvalue::Cast(CastKind::Pointer(PointerCast::UnsafeFnPointer), operand, ty)
 471                 | Rvalue::Cast(CastKind::Pointer(PointerCast::MutToConstPointer), operand, ty) => {
 472                     let operand = trans_operand(fx, operand);
 473                     let layout = fx.layout_of(ty);
 474                     lval.write_cvalue(fx, operand.unchecked_cast_to(layout));
 475                 }
 476                 Rvalue::Cast(CastKind::Misc, operand, to_ty) => {
 477                     let operand = trans_operand(fx, operand);
 478                     let from_ty = operand.layout().ty;
 479
 480                     fn is_fat_ptr<'a, 'tcx: 'a>(fx: &FunctionCx<'a, 'tcx, impl Backend>, ty: Ty<'tcx>) -> bool {
 481                         ty
 482                             .builtin_deref(true)
 483                             .map(|ty::TypeAndMut {ty: pointee_ty, mutbl: _ }| fx.layout_of(pointee_ty).is_unsized())
 484                             .unwrap_or(false)
 485                     }
 486
 487                     if is_fat_ptr(fx, from_ty) {
 488                         if is_fat_ptr(fx, to_ty) {
 489                             // fat-ptr -> fat-ptr
 490                             lval.write_cvalue(fx, operand.unchecked_cast_to(dest_layout));
 491                         } else {
 492                             // fat-ptr -> thin-ptr
 493                             let (ptr, _extra) = operand.load_scalar_pair(fx);
 494                             lval.write_cvalue(fx, CValue::by_val(ptr, dest_layout))
 495                         }
 496                     } else if let ty::Adt(adt_def, _substs) = from_ty.sty {
 497                         // enum -> discriminant value
 498                         assert!(adt_def.is_enum());
 499                         match to_ty.sty {
 500                             ty::Uint(_) | ty::Int(_) => {},
 501                             _ => unreachable!("cast adt {} -> {}", from_ty, to_ty),
 502                         }
 503
 504                         // FIXME avoid forcing to stack
 505                         let place =
 506                             CPlace::for_addr(operand.force_stack(fx), operand.layout());
 507                         let discr = trans_get_discriminant(fx, place, fx.layout_of(to_ty));
 508                         lval.write_cvalue(fx, discr);
 509                     } else {
 510                         let from_clif_ty = fx.clif_type(from_ty).unwrap();
 511                         let to_clif_ty = fx.clif_type(to_ty).unwrap();
 512                         let from = operand.load_scalar(fx);
 513
 514                         let signed = match from_ty.sty {
 515                             ty::Ref(..) | ty::RawPtr(..) | ty::FnPtr(..) | ty::Char | ty::Uint(..) | ty::Bool => false,
 516                             ty::Int(..) => true,
 517                             ty::Float(..) => false, // `signed` is unused for floats
 518                             _ => panic!("{}", from_ty),
 519                         };
 520
 521                         let res = if from_clif_ty.is_int() && to_clif_ty.is_int() {
 522                             // int-like -> int-like
 523                             crate::common::clif_intcast(
 524                                 fx,
 525                                 from,
 526                                 to_clif_ty,
 527                                 signed,
 528                             )
 529                         } else if from_clif_ty.is_int() && to_clif_ty.is_float() {
 530                             // int-like -> float
 531                             if signed {
 532                                 fx.bcx.ins().fcvt_from_sint(to_clif_ty, from)
 533                             } else {
 534                                 fx.bcx.ins().fcvt_from_uint(to_clif_ty, from)
 535                             }
 536                         } else if from_clif_ty.is_float() && to_clif_ty.is_int() {
 537                             // float -> int-like
 538                             let from = operand.load_scalar(fx);
 539                             if signed {
 540                                 fx.bcx.ins().fcvt_to_sint_sat(to_clif_ty, from)
 541                             } else {
 542                                 fx.bcx.ins().fcvt_to_uint_sat(to_clif_ty, from)
 543                             }
 544                         } else if from_clif_ty.is_float() && to_clif_ty.is_float() {
 545                             // float -> float
 546                             match (from_clif_ty, to_clif_ty) {
 547                                 (types::F32, types::F64) => {
 548                                     fx.bcx.ins().fpromote(types::F64, from)
 549                                 }
 550                                 (types::F64, types::F32) => {
 551                                     fx.bcx.ins().fdemote(types::F32, from)
 552                                 }
 553                                 _ => from,
 554                             }
 555                         } else {
 556                             unimpl!("rval misc {:?} {:?}", from_ty, to_ty)
 557                         };
 558                         lval.write_cvalue(fx, CValue::by_val(res, dest_layout));
 559                     }
 560                 }
 561                 Rvalue::Cast(CastKind::Pointer(PointerCast::ClosureFnPointer(_)), operand, _ty) => {
 562                     let operand = trans_operand(fx, operand);
 563                     match operand.layout().ty.sty {
 564                         ty::Closure(def_id, substs) => {
 565                             let instance = Instance::resolve_closure(
 566                                 fx.tcx,
 567                                 def_id,
 568                                 substs,
 569                                 ty::ClosureKind::FnOnce,
 570                             );
 571                             let func_ref = fx.get_function_ref(instance);
 572                             let func_addr = fx.bcx.ins().func_addr(fx.pointer_type, func_ref);
 573                             lval.write_cvalue(fx, CValue::by_val(func_addr, lval.layout()));
 574                         }
 575                         _ => {
 576                             bug!("{} cannot be cast to a fn ptr", operand.layout().ty)
 577                         }
 578                     }
 579                 }
 580                 Rvalue::Cast(CastKind::Pointer(PointerCast::Unsize), operand, _ty) => {
 581                     let operand = trans_operand(fx, operand);
 582                     operand.unsize_value(fx, lval);
 583                 }
 584                 Rvalue::Discriminant(place) => {
 585                     let place = trans_place(fx, place);
 586                     let discr = trans_get_discriminant(fx, place, dest_layout);
 587                     lval.write_cvalue(fx, discr);
 588                 }
 589                 Rvalue::Repeat(operand, times) => {
 590                     let operand = trans_operand(fx, operand);
 591                     for i in 0..*times {
 592                         let index = fx.bcx.ins().iconst(fx.pointer_type, i as i64);
 593                         let to = lval.place_index(fx, index);
 594                         to.write_cvalue(fx, operand);
 595                     }
 596                 }
 597                 Rvalue::Len(place) => {
 598                     let place = trans_place(fx, place);
 599                     let usize_layout = fx.layout_of(fx.tcx.types.usize);
 600                     let len = codegen_array_len(fx, place);
 601                     lval.write_cvalue(fx, CValue::by_val(len, usize_layout));
 602                 }
 603                 Rvalue::NullaryOp(NullOp::Box, content_ty) => {
 604                     use rustc::middle::lang_items::ExchangeMallocFnLangItem;
 605
 606                     let usize_type = fx.clif_type(fx.tcx.types.usize).unwrap();
 607                     let layout = fx.layout_of(content_ty);
 608                     let llsize = fx.bcx.ins().iconst(usize_type, layout.size.bytes() as i64);
 609                     let llalign = fx
 610                         .bcx
 611                         .ins()
 612                         .iconst(usize_type, layout.align.abi.bytes() as i64);
 613                     let box_layout = fx.layout_of(fx.tcx.mk_box(content_ty));
 614
 615                     // Allocate space:
 616                     let def_id = match fx.tcx.lang_items().require(ExchangeMallocFnLangItem) {
 617                         Ok(id) => id,
 618                         Err(s) => {
 619                             fx.tcx
 620                                 .sess
 621                                 .fatal(&format!("allocation of `{}` {}", box_layout.ty, s));
 622                         }
 623                     };
 624                     let instance = ty::Instance::mono(fx.tcx, def_id);
 625                     let func_ref = fx.get_function_ref(instance);
 626                     let call = fx.bcx.ins().call(func_ref, &[llsize, llalign]);
 627                     let ptr = fx.bcx.inst_results(call)[0];
 628                     lval.write_cvalue(fx, CValue::by_val(ptr, box_layout));
 629                 }
 630                 Rvalue::NullaryOp(NullOp::SizeOf, ty) => {
 631                     assert!(lval
 632                         .layout()
 633                         .ty
 634                         .is_sized(fx.tcx.at(DUMMY_SP), ParamEnv::reveal_all()));
 635                     let ty_size = fx.layout_of(ty).size.bytes();
 636                     let val = CValue::const_val(fx, fx.tcx.types.usize, ty_size as i64);
 637                     lval.write_cvalue(fx, val);
 638                 }
 639                 Rvalue::Aggregate(kind, operands) => match **kind {
 640                     AggregateKind::Array(_ty) => {
 641                         for (i, operand) in operands.into_iter().enumerate() {
 642                             let operand = trans_operand(fx, operand);
 643                             let index = fx.bcx.ins().iconst(fx.pointer_type, i as i64);
 644                             let to = lval.place_index(fx, index);
 645                             to.write_cvalue(fx, operand);
 646                         }
 647                     }
 648                     _ => unimpl!("shouldn't exist at trans {:?}", rval),
 649                 },
 650             }
 651         }
 652         StatementKind::StorageLive(_)
 653         | StatementKind::StorageDead(_)
 654         | StatementKind::Nop
 655         | StatementKind::FakeRead(..)
 656         | StatementKind::Retag { .. }
 657         | StatementKind::AscribeUserType(..) => {}
 658
 659         StatementKind::InlineAsm(asm) => {
 660             use syntax::ast::Name;
 661             let InlineAsm { asm, outputs: _, inputs: _ } = &**asm;
 662             let rustc::hir::InlineAsm {
 663                 asm: asm_code, // Name
 664                 outputs, // Vec<Name>
 665                 inputs, // Vec<Name>
 666                 clobbers, // Vec<Name>
 667                 volatile, // bool
 668                 alignstack, // bool
 669                 dialect, // syntax::ast::AsmDialect
 670                 asm_str_style: _,
 671                 ctxt: _,
 672             } = asm;
 673             match &*asm_code.as_str() {
 674                 "cpuid" | "cpuid\n" => {
 675                     assert_eq!(inputs, &[Name::intern("{eax}"), Name::intern("{ecx}")]);
 676
 677                     assert_eq!(outputs.len(), 4);
 678                     for (i, c) in (&["={eax}", "={ebx}", "={ecx}", "={edx}"]).iter().enumerate() {
 679                         assert_eq!(&outputs[i].constraint.as_str(), c);
 680                         assert!(!outputs[i].is_rw);
 681                         assert!(!outputs[i].is_indirect);
 682                     }
 683
 684                     assert_eq!(clobbers, &[Name::intern("rbx")]);
 685
 686                     assert!(!volatile);
 687                     assert!(!alignstack);
 688
 689                     crate::trap::trap_unimplemented(fx, "__cpuid_count arch intrinsic is not supported");
 690                 }
 691                 "xgetbv" => {
 692                     assert_eq!(inputs, &[Name::intern("{ecx}")]);
 693
 694                     assert_eq!(outputs.len(), 2);
 695                     for (i, c) in (&["={eax}", "={edx}"]).iter().enumerate() {
 696                         assert_eq!(&outputs[i].constraint.as_str(), c);
 697                         assert!(!outputs[i].is_rw);
 698                         assert!(!outputs[i].is_indirect);
 699                     }
 700
 701                     assert_eq!(clobbers, &[]);
 702
 703                     assert!(!volatile);
 704                     assert!(!alignstack);
 705
 706                     crate::trap::trap_unimplemented(fx, "_xgetbv arch intrinsic is not supported");
 707                 }
 708                 _ => unimpl!("Inline assembly is not supported"),
 709             }
 710         }
 711     }
 712 }
 713
 714 fn codegen_array_len<'a, 'tcx: 'a>(
 715     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 716     place: CPlace<'tcx>,
 717 ) -> Value {
 718     match place.layout().ty.sty {
 719         ty::Array(_elem_ty, len) => {
 720             let len = crate::constant::force_eval_const(fx, len).unwrap_usize(fx.tcx) as i64;
 721             fx.bcx.ins().iconst(fx.pointer_type, len)
 722         }
 723         ty::Slice(_elem_ty) => place
 724             .to_addr_maybe_unsized(fx)
 725             .1
 726             .expect("Length metadata for slice place"),
 727         _ => bug!("Rvalue::Len({:?})", place),
 728     }
 729 }
 730
 731 pub fn trans_get_discriminant<'a, 'tcx: 'a>(
 732     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 733     place: CPlace<'tcx>,
 734     dest_layout: TyLayout<'tcx>,
 735 ) -> CValue<'tcx> {
 736     let layout = place.layout();
 737
 738     if layout.abi == layout::Abi::Uninhabited {
 739         return trap_unreachable_ret_value(fx, dest_layout, "[panic] Tried to get discriminant for uninhabited type.");
 740     }
 741
 742     let (discr_scalar, discr_index, discr_kind) = match &layout.variants {
 743         layout::Variants::Single { index } => {
 744             let discr_val = layout
 745                 .ty
 746                 .ty_adt_def()
 747                 .map_or(index.as_u32() as u128, |def| {
 748                     def.discriminant_for_variant(fx.tcx, *index).val
 749                 });
 750             return CValue::const_val(fx, dest_layout.ty, discr_val as u64 as i64);
 751         }
 752         layout::Variants::Multiple { discr, discr_index, discr_kind, variants: _ } => {
 753             (discr, *discr_index, discr_kind)
 754         }
 755     };
 756
 757     let discr = place.place_field(fx, mir::Field::new(discr_index)).to_cvalue(fx);
 758     let discr_ty = discr.layout().ty;
 759     let lldiscr = discr.load_scalar(fx);
 760     match discr_kind {
 761         layout::DiscriminantKind::Tag => {
 762             let signed = match discr_scalar.value {
 763                 layout::Int(_, signed) => signed,
 764                 _ => false,
 765             };
 766             let val = clif_intcast(fx, lldiscr, fx.clif_type(dest_layout.ty).unwrap(), signed);
 767             return CValue::by_val(val, dest_layout);
 768         }
 769         layout::DiscriminantKind::Niche {
 770             dataful_variant,
 771             ref niche_variants,
 772             niche_start,
 773         } => {
 774             let niche_llty = fx.clif_type(discr_ty).unwrap();
 775             let dest_clif_ty = fx.clif_type(dest_layout.ty).unwrap();
 776             if niche_variants.start() == niche_variants.end() {
 777                 let b = fx
 778                     .bcx
 779                     .ins()
 780                     .icmp_imm(IntCC::Equal, lldiscr, *niche_start as u64 as i64);
 781                 let if_true = fx
 782                     .bcx
 783                     .ins()
 784                     .iconst(dest_clif_ty, niche_variants.start().as_u32() as i64);
 785                 let if_false = fx
 786                     .bcx
 787                     .ins()
 788                     .iconst(dest_clif_ty, dataful_variant.as_u32() as i64);
 789                 let val = fx.bcx.ins().select(b, if_true, if_false);
 790                 return CValue::by_val(val, dest_layout);
 791             } else {
 792                 // Rebase from niche values to discriminant values.
 793                 let delta = niche_start.wrapping_sub(niche_variants.start().as_u32() as u128);
 794                 let delta = fx.bcx.ins().iconst(niche_llty, delta as u64 as i64);
 795                 let lldiscr = fx.bcx.ins().isub(lldiscr, delta);
 796                 let b = fx.bcx.ins().icmp_imm(
 797                     IntCC::UnsignedLessThanOrEqual,
 798                     lldiscr,
 799                     niche_variants.end().as_u32() as i64,
 800                 );
 801                 let if_true =
 802                     clif_intcast(fx, lldiscr, fx.clif_type(dest_layout.ty).unwrap(), false);
 803                 let if_false = fx
 804                     .bcx
 805                     .ins()
 806                     .iconst(dest_clif_ty, dataful_variant.as_u32() as i64);
 807                 let val = fx.bcx.ins().select(b, if_true, if_false);
 808                 return CValue::by_val(val, dest_layout);
 809             }
 810         }
 811     }
 812 }
 813
 814 macro_rules! binop_match {
 815     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, bug) => {
 816         bug!("binop {} on {} lhs: {:?} rhs: {:?}", stringify!($var), $bug_fmt, $lhs, $rhs)
 817     };
 818     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, icmp($cc:ident)) => {{
 819         assert_eq!($fx.tcx.types.bool, $ret_ty);
 820         let ret_layout = $fx.layout_of($ret_ty);
 821
 822         let b = $fx.bcx.ins().icmp(IntCC::$cc, $lhs, $rhs);
 823         CValue::by_val($fx.bcx.ins().bint(types::I8, b), ret_layout)
 824     }};
 825     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, fcmp($cc:ident)) => {{
 826         assert_eq!($fx.tcx.types.bool, $ret_ty);
 827         let ret_layout = $fx.layout_of($ret_ty);
 828         let b = $fx.bcx.ins().fcmp(FloatCC::$cc, $lhs, $rhs);
 829         CValue::by_val($fx.bcx.ins().bint(types::I8, b), ret_layout)
 830     }};
 831     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, custom(|| $body:expr)) => {{
 832         $body
 833     }};
 834     (@single $fx:expr, $bug_fmt:expr, $var:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, $name:ident) => {{
 835         let ret_layout = $fx.layout_of($ret_ty);
 836         CValue::by_val($fx.bcx.ins().$name($lhs, $rhs), ret_layout)
 837     }};
 838     (
 839         $fx:expr, $bin_op:expr, $signed:expr, $lhs:expr, $rhs:expr, $ret_ty:expr, $bug_fmt:expr;
 840         $(
 841             $var:ident ($sign:pat) $name:tt $( ( $($next:tt)* ) )? ;
 842         )*
 843     ) => {{
 844         let lhs = $lhs.load_scalar($fx);
 845         let rhs = $rhs.load_scalar($fx);
 846         match ($bin_op, $signed) {
 847             $(
 848                 (BinOp::$var, $sign) => binop_match!(@single $fx, $bug_fmt, $var, $signed, lhs, rhs, $ret_ty, $name $( ( $($next)* ) )?),
 849             )*
 850         }
 851     }}
 852 }
 853
 854 fn trans_bool_binop<'a, 'tcx: 'a>(
 855     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 856     bin_op: BinOp,
 857     lhs: CValue<'tcx>,
 858     rhs: CValue<'tcx>,
 859     ty: Ty<'tcx>,
 860 ) -> CValue<'tcx> {
 861     let res = binop_match! {
 862         fx, bin_op, false, lhs, rhs, ty, "bool";
 863         Add (_) bug;
 864         Sub (_) bug;
 865         Mul (_) bug;
 866         Div (_) bug;
 867         Rem (_) bug;
 868         BitXor (_) bxor;
 869         BitAnd (_) band;
 870         BitOr (_) bor;
 871         Shl (_) bug;
 872         Shr (_) bug;
 873
 874         Eq (_) icmp(Equal);
 875         Lt (_) icmp(UnsignedLessThan);
 876         Le (_) icmp(UnsignedLessThanOrEqual);
 877         Ne (_) icmp(NotEqual);
 878         Ge (_) icmp(UnsignedGreaterThanOrEqual);
 879         Gt (_) icmp(UnsignedGreaterThan);
 880
 881         Offset (_) bug;
 882     };
 883
 884     res
 885 }
 886
 887 pub fn trans_int_binop<'a, 'tcx: 'a>(
 888     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 889     bin_op: BinOp,
 890     lhs: CValue<'tcx>,
 891     rhs: CValue<'tcx>,
 892     out_ty: Ty<'tcx>,
 893     signed: bool,
 894 ) -> CValue<'tcx> {
 895     if bin_op != BinOp::Shl && bin_op != BinOp::Shr {
 896         assert_eq!(
 897             lhs.layout().ty,
 898             rhs.layout().ty,
 899             "int binop requires lhs and rhs of same type"
 900         );
 901     }
 902     binop_match! {
 903         fx, bin_op, signed, lhs, rhs, out_ty, "int/uint";
 904         Add (_) iadd;
 905         Sub (_) isub;
 906         Mul (_) imul;
 907         Div (false) udiv;
 908         Div (true) sdiv;
 909         Rem (false) urem;
 910         Rem (true) srem;
 911         BitXor (_) bxor;
 912         BitAnd (_) band;
 913         BitOr (_) bor;
 914         Shl (_) ishl;
 915         Shr (false) ushr;
 916         Shr (true) sshr;
 917
 918         Eq (_) icmp(Equal);
 919         Lt (false) icmp(UnsignedLessThan);
 920         Lt (true) icmp(SignedLessThan);
 921         Le (false) icmp(UnsignedLessThanOrEqual);
 922         Le (true) icmp(SignedLessThanOrEqual);
 923         Ne (_) icmp(NotEqual);
 924         Ge (false) icmp(UnsignedGreaterThanOrEqual);
 925         Ge (true) icmp(SignedGreaterThanOrEqual);
 926         Gt (false) icmp(UnsignedGreaterThan);
 927         Gt (true) icmp(SignedGreaterThan);
 928
 929         Offset (_) bug;
 930     }
 931 }
 932
 933 pub fn trans_checked_int_binop<'a, 'tcx: 'a>(
 934     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
 935     bin_op: BinOp,
 936     in_lhs: CValue<'tcx>,
 937     in_rhs: CValue<'tcx>,
 938     out_ty: Ty<'tcx>,
 939     signed: bool,
 940 ) -> CValue<'tcx> {
 941     if bin_op != BinOp::Shl && bin_op != BinOp::Shr {
 942         assert_eq!(
 943             in_lhs.layout().ty,
 944             in_rhs.layout().ty,
 945             "checked int binop requires lhs and rhs of same type"
 946         );
 947     }
 948
 949     let lhs = in_lhs.load_scalar(fx);
 950     let rhs = in_rhs.load_scalar(fx);
 951     let res = match bin_op {
 952         BinOp::Add => fx.bcx.ins().iadd(lhs, rhs),
 953         BinOp::Sub => fx.bcx.ins().isub(lhs, rhs),
 954         BinOp::Mul => fx.bcx.ins().imul(lhs, rhs),
 955         BinOp::Shl => fx.bcx.ins().ishl(lhs, rhs),
 956         BinOp::Shr => {
 957             if !signed {
 958                 fx.bcx.ins().ushr(lhs, rhs)
 959             } else {
 960                 fx.bcx.ins().sshr(lhs, rhs)
 961             }
 962         }
 963         _ => bug!(
 964             "binop {:?} on checked int/uint lhs: {:?} rhs: {:?}",
 965             bin_op,
 966             in_lhs,
 967             in_rhs
 968         ),
 969     };
 970
 971     // TODO: check for overflow
 972     let has_overflow = fx.bcx.ins().iconst(types::I8, 0);
 973
 974     let out_place = CPlace::new_stack_slot(fx, out_ty);
 975     let out_layout = out_place.layout();
 976     out_place.write_cvalue(fx, CValue::by_val_pair(res, has_overflow, out_layout));
 977
 978     out_place.to_cvalue(fx)
 979 }
 980
 981 fn trans_float_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, "float";
 990         Add (_) fadd;
 991         Sub (_) fsub;
 992         Mul (_) fmul;
 993         Div (_) fdiv;
 994         Rem (_) custom(|| {
 995             assert_eq!(lhs.layout().ty, ty);
 996             assert_eq!(rhs.layout().ty, ty);
 997             match ty.sty {
 998                 ty::Float(FloatTy::F32) => fx.easy_call("fmodf", &[lhs, rhs], ty),
 999                 ty::Float(FloatTy::F64) => fx.easy_call("fmod", &[lhs, rhs], ty),
1000                 _ => bug!(),
1001             }
1002         });
1003         BitXor (_) bxor;
1004         BitAnd (_) band;
1005         BitOr (_) bor;
1006         Shl (_) bug;
1007         Shr (_) bug;
1008
1009         Eq (_) fcmp(Equal);
1010         Lt (_) fcmp(LessThan);
1011         Le (_) fcmp(LessThanOrEqual);
1012         Ne (_) fcmp(NotEqual);
1013         Ge (_) fcmp(GreaterThanOrEqual);
1014         Gt (_) fcmp(GreaterThan);
1015
1016         Offset (_) bug;
1017     };
1018
1019     res
1020 }
1021
1022 fn trans_char_binop<'a, 'tcx: 'a>(
1023     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
1024     bin_op: BinOp,
1025     lhs: CValue<'tcx>,
1026     rhs: CValue<'tcx>,
1027     ty: Ty<'tcx>,
1028 ) -> CValue<'tcx> {
1029     let res = binop_match! {
1030         fx, bin_op, false, lhs, rhs, ty, "char";
1031         Add (_) bug;
1032         Sub (_) bug;
1033         Mul (_) bug;
1034         Div (_) bug;
1035         Rem (_) bug;
1036         BitXor (_) bug;
1037         BitAnd (_) bug;
1038         BitOr (_) bug;
1039         Shl (_) bug;
1040         Shr (_) bug;
1041
1042         Eq (_) icmp(Equal);
1043         Lt (_) icmp(UnsignedLessThan);
1044         Le (_) icmp(UnsignedLessThanOrEqual);
1045         Ne (_) icmp(NotEqual);
1046         Ge (_) icmp(UnsignedGreaterThanOrEqual);
1047         Gt (_) icmp(UnsignedGreaterThan);
1048
1049         Offset (_) bug;
1050     };
1051
1052     res
1053 }
1054
1055 fn trans_ptr_binop<'a, 'tcx: 'a>(
1056     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
1057     bin_op: BinOp,
1058     lhs: CValue<'tcx>,
1059     rhs: CValue<'tcx>,
1060     ret_ty: Ty<'tcx>,
1061 ) -> CValue<'tcx> {
1062     let not_fat = match lhs.layout().ty.sty {
1063         ty::RawPtr(TypeAndMut { ty, mutbl: _ }) => {
1064             ty.is_sized(fx.tcx.at(DUMMY_SP), ParamEnv::reveal_all())
1065         }
1066         ty::FnPtr(..) => true,
1067         _ => bug!("trans_ptr_binop on non ptr"),
1068     };
1069     if not_fat {
1070         if let BinOp::Offset = bin_op {
1071             let (base, offset) = (lhs, rhs.load_scalar(fx));
1072             let pointee_ty = base.layout().ty.builtin_deref(true).unwrap().ty;
1073             let pointee_size = fx.layout_of(pointee_ty).size.bytes();
1074             let ptr_diff = fx.bcx.ins().imul_imm(offset, pointee_size as i64);
1075             let base_val = base.load_scalar(fx);
1076             let res = fx.bcx.ins().iadd(base_val, ptr_diff);
1077             return CValue::by_val(res, base.layout());
1078         }
1079
1080         binop_match! {
1081             fx, bin_op, false, lhs, rhs, ret_ty, "ptr";
1082             Add (_) bug;
1083             Sub (_) bug;
1084             Mul (_) bug;
1085             Div (_) bug;
1086             Rem (_) bug;
1087             BitXor (_) bug;
1088             BitAnd (_) bug;
1089             BitOr (_) bug;
1090             Shl (_) bug;
1091             Shr (_) bug;
1092
1093             Eq (_) icmp(Equal);
1094             Lt (_) icmp(UnsignedLessThan);
1095             Le (_) icmp(UnsignedLessThanOrEqual);
1096             Ne (_) icmp(NotEqual);
1097             Ge (_) icmp(UnsignedGreaterThanOrEqual);
1098             Gt (_) icmp(UnsignedGreaterThan);
1099
1100             Offset (_) bug; // Handled above
1101         }
1102     } else {
1103         let (lhs_ptr, lhs_extra) = lhs.load_scalar_pair(fx);
1104         let (rhs_ptr, rhs_extra) = rhs.load_scalar_pair(fx);
1105
1106         let res = match bin_op {
1107             BinOp::Eq => {
1108                 let ptr_eq = fx.bcx.ins().icmp(IntCC::Equal, lhs_ptr, rhs_ptr);
1109                 let extra_eq = fx.bcx.ins().icmp(IntCC::Equal, lhs_extra, rhs_extra);
1110                 fx.bcx.ins().band(ptr_eq, extra_eq)
1111             }
1112             BinOp::Ne => {
1113                 let ptr_ne = fx.bcx.ins().icmp(IntCC::NotEqual, lhs_ptr, rhs_ptr);
1114                 let extra_ne = fx.bcx.ins().icmp(IntCC::NotEqual, lhs_extra, rhs_extra);
1115                 fx.bcx.ins().bor(ptr_ne, extra_ne)
1116             }
1117             BinOp::Lt | BinOp::Le | BinOp::Ge | BinOp::Gt => {
1118                 let ptr_eq = fx.bcx.ins().icmp(IntCC::Equal, lhs_ptr, rhs_ptr);
1119
1120                 let ptr_cmp = fx.bcx.ins().icmp(match bin_op {
1121                     BinOp::Lt => IntCC::UnsignedLessThan,
1122                     BinOp::Le => IntCC::UnsignedLessThanOrEqual,
1123                     BinOp::Ge => IntCC::UnsignedGreaterThanOrEqual,
1124                     BinOp::Gt => IntCC::UnsignedGreaterThan,
1125                     _ => unreachable!(),
1126                 }, lhs_ptr, rhs_ptr);
1127
1128                 let extra_cmp = fx.bcx.ins().icmp(match bin_op {
1129                     BinOp::Lt => IntCC::UnsignedLessThan,
1130                     BinOp::Le => IntCC::UnsignedLessThanOrEqual,
1131                     BinOp::Ge => IntCC::UnsignedGreaterThanOrEqual,
1132                     BinOp::Gt => IntCC::UnsignedGreaterThan,
1133                     _ => unreachable!(),
1134                 }, lhs_extra, rhs_extra);
1135
1136                 fx.bcx.ins().select(ptr_eq, extra_cmp, ptr_cmp)
1137             }
1138             _ => panic!("bin_op {:?} on ptr", bin_op),
1139         };
1140
1141         assert_eq!(fx.tcx.types.bool, ret_ty);
1142         let ret_layout = fx.layout_of(ret_ty);
1143         CValue::by_val(fx.bcx.ins().bint(types::I8, res), ret_layout)
1144     }
1145 }
1146
1147 pub fn trans_place<'a, 'tcx: 'a>(
1148     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
1149     place: &Place<'tcx>,
1150 ) -> CPlace<'tcx> {
1151     match place {
1152         Place::Base(base) => match base {
1153             PlaceBase::Local(local) => fx.get_local_place(*local),
1154             PlaceBase::Static(static_) => match static_.kind {
1155                 StaticKind::Static(def_id) => {
1156                     crate::constant::codegen_static_ref(fx, def_id, static_.ty)
1157                 }
1158                 StaticKind::Promoted(promoted) => {
1159                     crate::constant::trans_promoted(fx, promoted, static_.ty)
1160                 }
1161             }
1162         }
1163         Place::Projection(projection) => {
1164             let base = trans_place(fx, &projection.base);
1165             match projection.elem {
1166                 ProjectionElem::Deref => base.place_deref(fx),
1167                 ProjectionElem::Field(field, _ty) => base.place_field(fx, field),
1168                 ProjectionElem::Index(local) => {
1169                     let index = fx.get_local_place(local).to_cvalue(fx).load_scalar(fx);
1170                     base.place_index(fx, index)
1171                 }
1172                 ProjectionElem::ConstantIndex {
1173                     offset,
1174                     min_length: _,
1175                     from_end,
1176                 } => {
1177                     let index = if !from_end {
1178                         fx.bcx.ins().iconst(fx.pointer_type, offset as i64)
1179                     } else {
1180                         let len = codegen_array_len(fx, base);
1181                         fx.bcx.ins().iadd_imm(len, -(offset as i64))
1182                     };
1183                     base.place_index(fx, index)
1184                 }
1185                 ProjectionElem::Subslice { from, to } => {
1186                     // These indices are generated by slice patterns.
1187                     // slice[from:-to] in Python terms.
1188
1189                     match base.layout().ty.sty {
1190                         ty::Array(elem_ty, len) => {
1191                             let elem_layout = fx.layout_of(elem_ty);
1192                             let ptr = base.to_addr(fx);
1193                             let len = crate::constant::force_eval_const(fx, len).unwrap_usize(fx.tcx);
1194                             CPlace::for_addr(
1195                                 fx.bcx.ins().iadd_imm(ptr, elem_layout.size.bytes() as i64 * from as i64),
1196                                 fx.layout_of(fx.tcx.mk_array(elem_ty, len - from as u64 - to as u64)),
1197                             )
1198                         }
1199                         ty::Slice(elem_ty) => {
1200                             let elem_layout = fx.layout_of(elem_ty);
1201                             let (ptr, len) = base.to_addr_maybe_unsized(fx);
1202                             let len = len.unwrap();
1203                             CPlace::for_addr_with_extra(
1204                                 fx.bcx.ins().iadd_imm(ptr, elem_layout.size.bytes() as i64 * from as i64),
1205                                 fx.bcx.ins().iadd_imm(len, -(from as i64 + to as i64)),
1206                                 base.layout(),
1207                             )
1208                         }
1209                         _ => unreachable!(),
1210                     }
1211                 }
1212                 ProjectionElem::Downcast(_adt_def, variant) => base.downcast_variant(fx, variant),
1213             }
1214         }
1215     }
1216 }
1217
1218 pub fn trans_operand<'a, 'tcx>(
1219     fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
1220     operand: &Operand<'tcx>,
1221 ) -> CValue<'tcx> {
1222     match operand {
1223         Operand::Move(place) | Operand::Copy(place) => {
1224             let cplace = trans_place(fx, place);
1225             cplace.to_cvalue(fx)
1226         }
1227         Operand::Constant(const_) => crate::constant::trans_constant(fx, const_),
1228     }
1229 }