compiler/rustc_typeck/src/check/intrinsic.rs

   1 //! Type-checking for the rust-intrinsic and platform-intrinsic
   2 //! intrinsics that the compiler exposes.
   3
   4 use crate::errors::{
   5     SimdShuffleMissingLength, UnrecognizedAtomicOperation, UnrecognizedIntrinsicFunction,
   6     WrongNumberOfGenericArgumentsToIntrinsic,
   7 };
   8 use crate::require_same_types;
   9
  10 use rustc_errors::{pluralize, struct_span_err};
  11 use rustc_hir as hir;
  12 use rustc_middle::traits::{ObligationCause, ObligationCauseCode};
  13 use rustc_middle::ty::subst::Subst;
  14 use rustc_middle::ty::{self, TyCtxt};
  15 use rustc_span::symbol::{kw, sym, Symbol};
  16 use rustc_target::spec::abi::Abi;
  17
  18 use std::iter;
  19
  20 fn equate_intrinsic_type<'tcx>(
  21     tcx: TyCtxt<'tcx>,
  22     it: &hir::ForeignItem<'_>,
  23     n_tps: usize,
  24     n_lts: usize,
  25     sig: ty::PolyFnSig<'tcx>,
  26 ) {
  27     let (own_counts, span) = match &it.kind {
  28         hir::ForeignItemKind::Fn(.., generics) => {
  29             let own_counts = tcx.generics_of(it.def_id.to_def_id()).own_counts();
  30             (own_counts, generics.span)
  31         }
  32         _ => {
  33             struct_span_err!(tcx.sess, it.span, E0622, "intrinsic must be a function")
  34                 .span_label(it.span, "expected a function")
  35                 .emit();
  36             return;
  37         }
  38     };
  39
  40     let gen_count_ok = |found: usize, expected: usize, descr: &str| -> bool {
  41         if found != expected {
  42             tcx.sess.emit_err(WrongNumberOfGenericArgumentsToIntrinsic {
  43                 span,
  44                 found,
  45                 expected,
  46                 expected_pluralize: pluralize!(expected),
  47                 descr,
  48             });
  49             false
  50         } else {
  51             true
  52         }
  53     };
  54
  55     if gen_count_ok(own_counts.lifetimes, n_lts, "lifetime")
  56         && gen_count_ok(own_counts.types, n_tps, "type")
  57         && gen_count_ok(own_counts.consts, 0, "const")
  58     {
  59         let fty = tcx.mk_fn_ptr(sig);
  60         let cause = ObligationCause::new(it.span, it.hir_id(), ObligationCauseCode::IntrinsicType);
  61         require_same_types(tcx, &cause, tcx.mk_fn_ptr(tcx.fn_sig(it.def_id)), fty);
  62     }
  63 }
  64
  65 /// Returns the unsafety of the given intrinsic.
  66 pub fn intrinsic_operation_unsafety(intrinsic: Symbol) -> hir::Unsafety {
  67     match intrinsic {
  68         // When adding a new intrinsic to this list,
  69         // it's usually worth updating that intrinsic's documentation
  70         // to note that it's safe to call, since
  71         // safe extern fns are otherwise unprecedented.
  72         sym::abort
  73         | sym::size_of
  74         | sym::min_align_of
  75         | sym::needs_drop
  76         | sym::caller_location
  77         | sym::add_with_overflow
  78         | sym::sub_with_overflow
  79         | sym::mul_with_overflow
  80         | sym::wrapping_add
  81         | sym::wrapping_sub
  82         | sym::wrapping_mul
  83         | sym::saturating_add
  84         | sym::saturating_sub
  85         | sym::rotate_left
  86         | sym::rotate_right
  87         | sym::ctpop
  88         | sym::ctlz
  89         | sym::cttz
  90         | sym::bswap
  91         | sym::bitreverse
  92         | sym::discriminant_value
  93         | sym::type_id
  94         | sym::likely
  95         | sym::unlikely
  96         | sym::ptr_guaranteed_eq
  97         | sym::ptr_guaranteed_ne
  98         | sym::minnumf32
  99         | sym::minnumf64
 100         | sym::maxnumf32
 101         | sym::rustc_peek
 102         | sym::maxnumf64
 103         | sym::type_name
 104         | sym::forget
 105         | sym::black_box
 106         | sym::variant_count => hir::Unsafety::Normal,
 107         _ => hir::Unsafety::Unsafe,
 108     }
 109 }
 110
 111 /// Remember to add all intrinsics here, in `compiler/rustc_codegen_llvm/src/intrinsic.rs`,
 112 /// and in `library/core/src/intrinsics.rs`.
 113 pub fn check_intrinsic_type(tcx: TyCtxt<'_>, it: &hir::ForeignItem<'_>) {
 114     let param = |n| tcx.mk_ty_param(n, Symbol::intern(&format!("P{}", n)));
 115     let intrinsic_name = tcx.item_name(it.def_id.to_def_id());
 116     let name_str = intrinsic_name.as_str();
 117
 118     let bound_vars = tcx.mk_bound_variable_kinds(
 119         [ty::BoundVariableKind::Region(ty::BrAnon(0)), ty::BoundVariableKind::Region(ty::BrEnv)]
 120             .iter()
 121             .copied(),
 122     );
 123     let mk_va_list_ty = |mutbl| {
 124         tcx.lang_items().va_list().map(|did| {
 125             let region = tcx.mk_region(ty::ReLateBound(
 126                 ty::INNERMOST,
 127                 ty::BoundRegion { var: ty::BoundVar::from_u32(0), kind: ty::BrAnon(0) },
 128             ));
 129             let env_region = tcx.mk_region(ty::ReLateBound(
 130                 ty::INNERMOST,
 131                 ty::BoundRegion { var: ty::BoundVar::from_u32(1), kind: ty::BrEnv },
 132             ));
 133             let va_list_ty = tcx.type_of(did).subst(tcx, &[region.into()]);
 134             (tcx.mk_ref(env_region, ty::TypeAndMut { ty: va_list_ty, mutbl }), va_list_ty)
 135         })
 136     };
 137
 138     let (n_tps, n_lts, inputs, output, unsafety) = if name_str.starts_with("atomic_") {
 139         let split: Vec<&str> = name_str.split('_').collect();
 140         assert!(split.len() >= 2, "Atomic intrinsic in an incorrect format");
 141
 142         //We only care about the operation here
 143         let (n_tps, inputs, output) = match split[1] {
 144             "cxchg" | "cxchgweak" => (
 145                 1,
 146                 vec![tcx.mk_mut_ptr(param(0)), param(0), param(0)],
 147                 tcx.intern_tup(&[param(0), tcx.types.bool]),
 148             ),
 149             "load" => (1, vec![tcx.mk_imm_ptr(param(0))], param(0)),
 150             "store" => (1, vec![tcx.mk_mut_ptr(param(0)), param(0)], tcx.mk_unit()),
 151
 152             "xchg" | "xadd" | "xsub" | "and" | "nand" | "or" | "xor" | "max" | "min" | "umax"
 153             | "umin" => (1, vec![tcx.mk_mut_ptr(param(0)), param(0)], param(0)),
 154             "fence" | "singlethreadfence" => (0, Vec::new(), tcx.mk_unit()),
 155             op => {
 156                 tcx.sess.emit_err(UnrecognizedAtomicOperation { span: it.span, op });
 157                 return;
 158             }
 159         };
 160         (n_tps, 0, inputs, output, hir::Unsafety::Unsafe)
 161     } else {
 162         let unsafety = intrinsic_operation_unsafety(intrinsic_name);
 163         let (n_tps, inputs, output) = match intrinsic_name {
 164             sym::abort => (0, Vec::new(), tcx.types.never),
 165             sym::unreachable => (0, Vec::new(), tcx.types.never),
 166             sym::breakpoint => (0, Vec::new(), tcx.mk_unit()),
 167             sym::size_of | sym::pref_align_of | sym::min_align_of | sym::variant_count => {
 168                 (1, Vec::new(), tcx.types.usize)
 169             }
 170             sym::size_of_val | sym::min_align_of_val => {
 171                 (1, vec![tcx.mk_imm_ptr(param(0))], tcx.types.usize)
 172             }
 173             sym::rustc_peek => (1, vec![param(0)], param(0)),
 174             sym::caller_location => (0, vec![], tcx.caller_location_ty()),
 175             sym::assert_inhabited | sym::assert_zero_valid | sym::assert_uninit_valid => {
 176                 (1, Vec::new(), tcx.mk_unit())
 177             }
 178             sym::forget => (1, vec![param(0)], tcx.mk_unit()),
 179             sym::transmute => (2, vec![param(0)], param(1)),
 180             sym::prefetch_read_data
 181             | sym::prefetch_write_data
 182             | sym::prefetch_read_instruction
 183             | sym::prefetch_write_instruction => (
 184                 1,
 185                 vec![
 186                     tcx.mk_ptr(ty::TypeAndMut { ty: param(0), mutbl: hir::Mutability::Not }),
 187                     tcx.types.i32,
 188                 ],
 189                 tcx.mk_unit(),
 190             ),
 191             sym::drop_in_place => (1, vec![tcx.mk_mut_ptr(param(0))], tcx.mk_unit()),
 192             sym::needs_drop => (1, Vec::new(), tcx.types.bool),
 193
 194             sym::type_name => (1, Vec::new(), tcx.mk_static_str()),
 195             sym::type_id => (1, Vec::new(), tcx.types.u64),
 196             sym::offset | sym::arith_offset => (
 197                 1,
 198                 vec![
 199                     tcx.mk_ptr(ty::TypeAndMut { ty: param(0), mutbl: hir::Mutability::Not }),
 200                     tcx.types.isize,
 201                 ],
 202                 tcx.mk_ptr(ty::TypeAndMut { ty: param(0), mutbl: hir::Mutability::Not }),
 203             ),
 204             sym::copy | sym::copy_nonoverlapping => (
 205                 1,
 206                 vec![
 207                     tcx.mk_ptr(ty::TypeAndMut { ty: param(0), mutbl: hir::Mutability::Not }),
 208                     tcx.mk_ptr(ty::TypeAndMut { ty: param(0), mutbl: hir::Mutability::Mut }),
 209                     tcx.types.usize,
 210                 ],
 211                 tcx.mk_unit(),
 212             ),
 213             sym::volatile_copy_memory | sym::volatile_copy_nonoverlapping_memory => (
 214                 1,
 215                 vec![
 216                     tcx.mk_ptr(ty::TypeAndMut { ty: param(0), mutbl: hir::Mutability::Mut }),
 217                     tcx.mk_ptr(ty::TypeAndMut { ty: param(0), mutbl: hir::Mutability::Not }),
 218                     tcx.types.usize,
 219                 ],
 220                 tcx.mk_unit(),
 221             ),
 222             sym::write_bytes | sym::volatile_set_memory => (
 223                 1,
 224                 vec![
 225                     tcx.mk_ptr(ty::TypeAndMut { ty: param(0), mutbl: hir::Mutability::Mut }),
 226                     tcx.types.u8,
 227                     tcx.types.usize,
 228                 ],
 229                 tcx.mk_unit(),
 230             ),
 231             sym::sqrtf32 => (0, vec![tcx.types.f32], tcx.types.f32),
 232             sym::sqrtf64 => (0, vec![tcx.types.f64], tcx.types.f64),
 233             sym::powif32 => (0, vec![tcx.types.f32, tcx.types.i32], tcx.types.f32),
 234             sym::powif64 => (0, vec![tcx.types.f64, tcx.types.i32], tcx.types.f64),
 235             sym::sinf32 => (0, vec![tcx.types.f32], tcx.types.f32),
 236             sym::sinf64 => (0, vec![tcx.types.f64], tcx.types.f64),
 237             sym::cosf32 => (0, vec![tcx.types.f32], tcx.types.f32),
 238             sym::cosf64 => (0, vec![tcx.types.f64], tcx.types.f64),
 239             sym::powf32 => (0, vec![tcx.types.f32, tcx.types.f32], tcx.types.f32),
 240             sym::powf64 => (0, vec![tcx.types.f64, tcx.types.f64], tcx.types.f64),
 241             sym::expf32 => (0, vec![tcx.types.f32], tcx.types.f32),
 242             sym::expf64 => (0, vec![tcx.types.f64], tcx.types.f64),
 243             sym::exp2f32 => (0, vec![tcx.types.f32], tcx.types.f32),
 244             sym::exp2f64 => (0, vec![tcx.types.f64], tcx.types.f64),
 245             sym::logf32 => (0, vec![tcx.types.f32], tcx.types.f32),
 246             sym::logf64 => (0, vec![tcx.types.f64], tcx.types.f64),
 247             sym::log10f32 => (0, vec![tcx.types.f32], tcx.types.f32),
 248             sym::log10f64 => (0, vec![tcx.types.f64], tcx.types.f64),
 249             sym::log2f32 => (0, vec![tcx.types.f32], tcx.types.f32),
 250             sym::log2f64 => (0, vec![tcx.types.f64], tcx.types.f64),
 251             sym::fmaf32 => (0, vec![tcx.types.f32, tcx.types.f32, tcx.types.f32], tcx.types.f32),
 252             sym::fmaf64 => (0, vec![tcx.types.f64, tcx.types.f64, tcx.types.f64], tcx.types.f64),
 253             sym::fabsf32 => (0, vec![tcx.types.f32], tcx.types.f32),
 254             sym::fabsf64 => (0, vec![tcx.types.f64], tcx.types.f64),
 255             sym::minnumf32 => (0, vec![tcx.types.f32, tcx.types.f32], tcx.types.f32),
 256             sym::minnumf64 => (0, vec![tcx.types.f64, tcx.types.f64], tcx.types.f64),
 257             sym::maxnumf32 => (0, vec![tcx.types.f32, tcx.types.f32], tcx.types.f32),
 258             sym::maxnumf64 => (0, vec![tcx.types.f64, tcx.types.f64], tcx.types.f64),
 259             sym::copysignf32 => (0, vec![tcx.types.f32, tcx.types.f32], tcx.types.f32),
 260             sym::copysignf64 => (0, vec![tcx.types.f64, tcx.types.f64], tcx.types.f64),
 261             sym::floorf32 => (0, vec![tcx.types.f32], tcx.types.f32),
 262             sym::floorf64 => (0, vec![tcx.types.f64], tcx.types.f64),
 263             sym::ceilf32 => (0, vec![tcx.types.f32], tcx.types.f32),
 264             sym::ceilf64 => (0, vec![tcx.types.f64], tcx.types.f64),
 265             sym::truncf32 => (0, vec![tcx.types.f32], tcx.types.f32),
 266             sym::truncf64 => (0, vec![tcx.types.f64], tcx.types.f64),
 267             sym::rintf32 => (0, vec![tcx.types.f32], tcx.types.f32),
 268             sym::rintf64 => (0, vec![tcx.types.f64], tcx.types.f64),
 269             sym::nearbyintf32 => (0, vec![tcx.types.f32], tcx.types.f32),
 270             sym::nearbyintf64 => (0, vec![tcx.types.f64], tcx.types.f64),
 271             sym::roundf32 => (0, vec![tcx.types.f32], tcx.types.f32),
 272             sym::roundf64 => (0, vec![tcx.types.f64], tcx.types.f64),
 273
 274             sym::volatile_load | sym::unaligned_volatile_load => {
 275                 (1, vec![tcx.mk_imm_ptr(param(0))], param(0))
 276             }
 277             sym::volatile_store | sym::unaligned_volatile_store => {
 278                 (1, vec![tcx.mk_mut_ptr(param(0)), param(0)], tcx.mk_unit())
 279             }
 280
 281             sym::ctpop
 282             | sym::ctlz
 283             | sym::ctlz_nonzero
 284             | sym::cttz
 285             | sym::cttz_nonzero
 286             | sym::bswap
 287             | sym::bitreverse => (1, vec![param(0)], param(0)),
 288
 289             sym::add_with_overflow | sym::sub_with_overflow | sym::mul_with_overflow => {
 290                 (1, vec![param(0), param(0)], tcx.intern_tup(&[param(0), tcx.types.bool]))
 291             }
 292
 293             sym::ptr_guaranteed_eq | sym::ptr_guaranteed_ne => {
 294                 (1, vec![tcx.mk_imm_ptr(param(0)), tcx.mk_imm_ptr(param(0))], tcx.types.bool)
 295             }
 296
 297             sym::const_allocate => {
 298                 (0, vec![tcx.types.usize, tcx.types.usize], tcx.mk_mut_ptr(tcx.types.u8))
 299             }
 300
 301             sym::ptr_offset_from => {
 302                 (1, vec![tcx.mk_imm_ptr(param(0)), tcx.mk_imm_ptr(param(0))], tcx.types.isize)
 303             }
 304             sym::unchecked_div | sym::unchecked_rem | sym::exact_div => {
 305                 (1, vec![param(0), param(0)], param(0))
 306             }
 307             sym::unchecked_shl | sym::unchecked_shr | sym::rotate_left | sym::rotate_right => {
 308                 (1, vec![param(0), param(0)], param(0))
 309             }
 310             sym::unchecked_add | sym::unchecked_sub | sym::unchecked_mul => {
 311                 (1, vec![param(0), param(0)], param(0))
 312             }
 313             sym::wrapping_add | sym::wrapping_sub | sym::wrapping_mul => {
 314                 (1, vec![param(0), param(0)], param(0))
 315             }
 316             sym::saturating_add | sym::saturating_sub => (1, vec![param(0), param(0)], param(0)),
 317             sym::fadd_fast | sym::fsub_fast | sym::fmul_fast | sym::fdiv_fast | sym::frem_fast => {
 318                 (1, vec![param(0), param(0)], param(0))
 319             }
 320             sym::float_to_int_unchecked => (2, vec![param(0)], param(1)),
 321
 322             sym::assume => (0, vec![tcx.types.bool], tcx.mk_unit()),
 323             sym::likely => (0, vec![tcx.types.bool], tcx.types.bool),
 324             sym::unlikely => (0, vec![tcx.types.bool], tcx.types.bool),
 325
 326             sym::discriminant_value => {
 327                 let assoc_items =
 328                     tcx.associated_items(tcx.lang_items().discriminant_kind_trait().unwrap());
 329                 let discriminant_def_id = assoc_items.in_definition_order().next().unwrap().def_id;
 330
 331                 let br = ty::BoundRegion { var: ty::BoundVar::from_u32(0), kind: ty::BrAnon(0) };
 332                 (
 333                     1,
 334                     vec![
 335                         tcx.mk_imm_ref(tcx.mk_region(ty::ReLateBound(ty::INNERMOST, br)), param(0)),
 336                     ],
 337                     tcx.mk_projection(discriminant_def_id, tcx.mk_substs([param(0).into()].iter())),
 338                 )
 339             }
 340
 341             kw::Try => {
 342                 let mut_u8 = tcx.mk_mut_ptr(tcx.types.u8);
 343                 let try_fn_ty = ty::Binder::dummy(tcx.mk_fn_sig(
 344                     iter::once(mut_u8),
 345                     tcx.mk_unit(),
 346                     false,
 347                     hir::Unsafety::Normal,
 348                     Abi::Rust,
 349                 ));
 350                 let catch_fn_ty = ty::Binder::dummy(tcx.mk_fn_sig(
 351                     [mut_u8, mut_u8].iter().cloned(),
 352                     tcx.mk_unit(),
 353                     false,
 354                     hir::Unsafety::Normal,
 355                     Abi::Rust,
 356                 ));
 357                 (
 358                     0,
 359                     vec![tcx.mk_fn_ptr(try_fn_ty), mut_u8, tcx.mk_fn_ptr(catch_fn_ty)],
 360                     tcx.types.i32,
 361                 )
 362             }
 363
 364             sym::va_start | sym::va_end => match mk_va_list_ty(hir::Mutability::Mut) {
 365                 Some((va_list_ref_ty, _)) => (0, vec![va_list_ref_ty], tcx.mk_unit()),
 366                 None => bug!("`va_list` language item needed for C-variadic intrinsics"),
 367             },
 368
 369             sym::va_copy => match mk_va_list_ty(hir::Mutability::Not) {
 370                 Some((va_list_ref_ty, va_list_ty)) => {
 371                     let va_list_ptr_ty = tcx.mk_mut_ptr(va_list_ty);
 372                     (0, vec![va_list_ptr_ty, va_list_ref_ty], tcx.mk_unit())
 373                 }
 374                 None => bug!("`va_list` language item needed for C-variadic intrinsics"),
 375             },
 376
 377             sym::va_arg => match mk_va_list_ty(hir::Mutability::Mut) {
 378                 Some((va_list_ref_ty, _)) => (1, vec![va_list_ref_ty], param(0)),
 379                 None => bug!("`va_list` language item needed for C-variadic intrinsics"),
 380             },
 381
 382             sym::nontemporal_store => (1, vec![tcx.mk_mut_ptr(param(0)), param(0)], tcx.mk_unit()),
 383
 384             sym::raw_eq => {
 385                 let br = ty::BoundRegion { var: ty::BoundVar::from_u32(0), kind: ty::BrAnon(0) };
 386                 let param_ty =
 387                     tcx.mk_imm_ref(tcx.mk_region(ty::ReLateBound(ty::INNERMOST, br)), param(0));
 388                 (1, vec![param_ty; 2], tcx.types.bool)
 389             }
 390
 391             sym::black_box => (1, vec![param(0)], param(0)),
 392
 393             other => {
 394                 tcx.sess.emit_err(UnrecognizedIntrinsicFunction { span: it.span, name: other });
 395                 return;
 396             }
 397         };
 398         (n_tps, 0, inputs, output, unsafety)
 399     };
 400     let sig = tcx.mk_fn_sig(inputs.into_iter(), output, false, unsafety, Abi::RustIntrinsic);
 401     let sig = ty::Binder::bind_with_vars(sig, bound_vars);
 402     equate_intrinsic_type(tcx, it, n_tps, n_lts, sig)
 403 }
 404
 405 /// Type-check `extern "platform-intrinsic" { ... }` functions.
 406 pub fn check_platform_intrinsic_type(tcx: TyCtxt<'_>, it: &hir::ForeignItem<'_>) {
 407     let param = |n| {
 408         let name = Symbol::intern(&format!("P{}", n));
 409         tcx.mk_ty_param(n, name)
 410     };
 411
 412     let name = it.ident.name;
 413
 414     let (n_tps, inputs, output) = match name {
 415         sym::simd_eq | sym::simd_ne | sym::simd_lt | sym::simd_le | sym::simd_gt | sym::simd_ge => {
 416             (2, vec![param(0), param(0)], param(1))
 417         }
 418         sym::simd_add
 419         | sym::simd_sub
 420         | sym::simd_mul
 421         | sym::simd_rem
 422         | sym::simd_div
 423         | sym::simd_shl
 424         | sym::simd_shr
 425         | sym::simd_and
 426         | sym::simd_or
 427         | sym::simd_xor
 428         | sym::simd_fmin
 429         | sym::simd_fmax
 430         | sym::simd_fpow
 431         | sym::simd_saturating_add
 432         | sym::simd_saturating_sub => (1, vec![param(0), param(0)], param(0)),
 433         sym::simd_neg
 434         | sym::simd_fsqrt
 435         | sym::simd_fsin
 436         | sym::simd_fcos
 437         | sym::simd_fexp
 438         | sym::simd_fexp2
 439         | sym::simd_flog2
 440         | sym::simd_flog10
 441         | sym::simd_flog
 442         | sym::simd_fabs
 443         | sym::simd_ceil
 444         | sym::simd_floor
 445         | sym::simd_round
 446         | sym::simd_trunc => (1, vec![param(0)], param(0)),
 447         sym::simd_fpowi => (1, vec![param(0), tcx.types.i32], param(0)),
 448         sym::simd_fma => (1, vec![param(0), param(0), param(0)], param(0)),
 449         sym::simd_gather => (3, vec![param(0), param(1), param(2)], param(0)),
 450         sym::simd_scatter => (3, vec![param(0), param(1), param(2)], tcx.mk_unit()),
 451         sym::simd_insert => (2, vec![param(0), tcx.types.u32, param(1)], param(0)),
 452         sym::simd_extract => (2, vec![param(0), tcx.types.u32], param(1)),
 453         sym::simd_cast => (2, vec![param(0)], param(1)),
 454         sym::simd_bitmask => (2, vec![param(0)], param(1)),
 455         sym::simd_select | sym::simd_select_bitmask => {
 456             (2, vec![param(0), param(1), param(1)], param(1))
 457         }
 458         sym::simd_reduce_all | sym::simd_reduce_any => (1, vec![param(0)], tcx.types.bool),
 459         sym::simd_reduce_add_ordered | sym::simd_reduce_mul_ordered => {
 460             (2, vec![param(0), param(1)], param(1))
 461         }
 462         sym::simd_reduce_add_unordered
 463         | sym::simd_reduce_mul_unordered
 464         | sym::simd_reduce_and
 465         | sym::simd_reduce_or
 466         | sym::simd_reduce_xor
 467         | sym::simd_reduce_min
 468         | sym::simd_reduce_max
 469         | sym::simd_reduce_min_nanless
 470         | sym::simd_reduce_max_nanless => (2, vec![param(0)], param(1)),
 471         name if name.as_str().starts_with("simd_shuffle") => {
 472             match name.as_str()["simd_shuffle".len()..].parse() {
 473                 Ok(n) => {
 474                     let params = vec![param(0), param(0), tcx.mk_array(tcx.types.u32, n)];
 475                     (2, params, param(1))
 476                 }
 477                 Err(_) => {
 478                     tcx.sess.emit_err(SimdShuffleMissingLength { span: it.span, name });
 479                     return;
 480                 }
 481             }
 482         }
 483         _ => {
 484             let msg = format!("unrecognized platform-specific intrinsic function: `{}`", name);
 485             tcx.sess.struct_span_err(it.span, &msg).emit();
 486             return;
 487         }
 488     };
 489
 490     let sig = tcx.mk_fn_sig(
 491         inputs.into_iter(),
 492         output,
 493         false,
 494         hir::Unsafety::Unsafe,
 495         Abi::PlatformIntrinsic,
 496     );
 497     let sig = ty::Binder::dummy(sig);
 498     equate_intrinsic_type(tcx, it, n_tps, 0, sig)
 499 }