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     UnrecognizedAtomicOperation, UnrecognizedIntrinsicFunction,
   6     WrongNumberOfGenericArgumentsToIntrinsic,
   7 };
   8 use crate::require_same_types;
   9
  10 use rustc_errors::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                 descr,
  47             });
  48             false
  49         } else {
  50             true
  51         }
  52     };
  53
  54     if gen_count_ok(own_counts.lifetimes, n_lts, "lifetime")
  55         && gen_count_ok(own_counts.types, n_tps, "type")
  56         && gen_count_ok(own_counts.consts, 0, "const")
  57     {
  58         let fty = tcx.mk_fn_ptr(sig);
  59         let cause = ObligationCause::new(it.span, it.hir_id(), ObligationCauseCode::IntrinsicType);
  60         require_same_types(tcx, &cause, tcx.mk_fn_ptr(tcx.fn_sig(it.def_id)), fty);
  61     }
  62 }
  63
  64 /// Returns the unsafety of the given intrinsic.
  65 pub fn intrinsic_operation_unsafety(intrinsic: Symbol) -> hir::Unsafety {
  66     match intrinsic {
  67         // When adding a new intrinsic to this list,
  68         // it's usually worth updating that intrinsic's documentation
  69         // to note that it's safe to call, since
  70         // safe extern fns are otherwise unprecedented.
  71         sym::abort
  72         | sym::assert_inhabited
  73         | sym::assert_zero_valid
  74         | sym::assert_uninit_valid
  75         | sym::size_of
  76         | sym::min_align_of
  77         | sym::needs_drop
  78         | sym::caller_location
  79         | sym::add_with_overflow
  80         | sym::sub_with_overflow
  81         | sym::mul_with_overflow
  82         | sym::wrapping_add
  83         | sym::wrapping_sub
  84         | sym::wrapping_mul
  85         | sym::saturating_add
  86         | sym::saturating_sub
  87         | sym::rotate_left
  88         | sym::rotate_right
  89         | sym::ctpop
  90         | sym::ctlz
  91         | sym::cttz
  92         | sym::bswap
  93         | sym::bitreverse
  94         | sym::discriminant_value
  95         | sym::type_id
  96         | sym::likely
  97         | sym::unlikely
  98         | sym::ptr_guaranteed_cmp
  99         | sym::minnumf32
 100         | sym::minnumf64
 101         | sym::maxnumf32
 102         | sym::rustc_peek
 103         | sym::maxnumf64
 104         | sym::type_name
 105         | sym::forget
 106         | sym::black_box
 107         | sym::variant_count
 108         | sym::ptr_mask => hir::Unsafety::Normal,
 109         _ => hir::Unsafety::Unsafe,
 110     }
 111 }
 112
 113 /// Remember to add all intrinsics here, in `compiler/rustc_codegen_llvm/src/intrinsic.rs`,
 114 /// and in `library/core/src/intrinsics.rs`.
 115 pub fn check_intrinsic_type(tcx: TyCtxt<'_>, it: &hir::ForeignItem<'_>) {
 116     let param = |n| tcx.mk_ty_param(n, Symbol::intern(&format!("P{}", n)));
 117     let intrinsic_name = tcx.item_name(it.def_id.to_def_id());
 118     let name_str = intrinsic_name.as_str();
 119
 120     let bound_vars = tcx.mk_bound_variable_kinds(
 121         [ty::BoundVariableKind::Region(ty::BrAnon(0)), ty::BoundVariableKind::Region(ty::BrEnv)]
 122             .iter()
 123             .copied(),
 124     );
 125     let mk_va_list_ty = |mutbl| {
 126         tcx.lang_items().va_list().map(|did| {
 127             let region = tcx.mk_region(ty::ReLateBound(
 128                 ty::INNERMOST,
 129                 ty::BoundRegion { var: ty::BoundVar::from_u32(0), kind: ty::BrAnon(0) },
 130             ));
 131             let env_region = tcx.mk_region(ty::ReLateBound(
 132                 ty::INNERMOST,
 133                 ty::BoundRegion { var: ty::BoundVar::from_u32(1), kind: ty::BrEnv },
 134             ));
 135             let va_list_ty = tcx.bound_type_of(did).subst(tcx, &[region.into()]);
 136             (tcx.mk_ref(env_region, ty::TypeAndMut { ty: va_list_ty, mutbl }), va_list_ty)
 137         })
 138     };
 139
 140     let (n_tps, n_lts, inputs, output, unsafety) = if name_str.starts_with("atomic_") {
 141         let split: Vec<&str> = name_str.split('_').collect();
 142         assert!(split.len() >= 2, "Atomic intrinsic in an incorrect format");
 143
 144         //We only care about the operation here
 145         let (n_tps, inputs, output) = match split[1] {
 146             "cxchg" | "cxchgweak" => (
 147                 1,
 148                 vec![tcx.mk_mut_ptr(param(0)), param(0), param(0)],
 149                 tcx.intern_tup(&[param(0), tcx.types.bool]),
 150             ),
 151             "load" => (1, vec![tcx.mk_imm_ptr(param(0))], param(0)),
 152             "store" => (1, vec![tcx.mk_mut_ptr(param(0)), param(0)], tcx.mk_unit()),
 153
 154             "xchg" | "xadd" | "xsub" | "and" | "nand" | "or" | "xor" | "max" | "min" | "umax"
 155             | "umin" => (1, vec![tcx.mk_mut_ptr(param(0)), param(0)], param(0)),
 156             "fence" | "singlethreadfence" => (0, Vec::new(), tcx.mk_unit()),
 157             op => {
 158                 tcx.sess.emit_err(UnrecognizedAtomicOperation { span: it.span, op });
 159                 return;
 160             }
 161         };
 162         (n_tps, 0, inputs, output, hir::Unsafety::Unsafe)
 163     } else {
 164         let unsafety = intrinsic_operation_unsafety(intrinsic_name);
 165         let (n_tps, inputs, output) = match intrinsic_name {
 166             sym::abort => (0, Vec::new(), tcx.types.never),
 167             sym::unreachable => (0, Vec::new(), tcx.types.never),
 168             sym::breakpoint => (0, Vec::new(), tcx.mk_unit()),
 169             sym::size_of | sym::pref_align_of | sym::min_align_of | sym::variant_count => {
 170                 (1, Vec::new(), tcx.types.usize)
 171             }
 172             sym::size_of_val | sym::min_align_of_val => {
 173                 (1, vec![tcx.mk_imm_ptr(param(0))], tcx.types.usize)
 174             }
 175             sym::rustc_peek => (1, vec![param(0)], param(0)),
 176             sym::caller_location => (0, vec![], tcx.caller_location_ty()),
 177             sym::assert_inhabited | sym::assert_zero_valid | sym::assert_uninit_valid => {
 178                 (1, Vec::new(), tcx.mk_unit())
 179             }
 180             sym::forget => (1, vec![param(0)], tcx.mk_unit()),
 181             sym::transmute => (2, vec![param(0)], param(1)),
 182             sym::prefetch_read_data
 183             | sym::prefetch_write_data
 184             | sym::prefetch_read_instruction
 185             | sym::prefetch_write_instruction => (
 186                 1,
 187                 vec![
 188                     tcx.mk_ptr(ty::TypeAndMut { ty: param(0), mutbl: hir::Mutability::Not }),
 189                     tcx.types.i32,
 190                 ],
 191                 tcx.mk_unit(),
 192             ),
 193             sym::drop_in_place => (1, vec![tcx.mk_mut_ptr(param(0))], tcx.mk_unit()),
 194             sym::needs_drop => (1, Vec::new(), tcx.types.bool),
 195
 196             sym::type_name => (1, Vec::new(), tcx.mk_static_str()),
 197             sym::type_id => (1, Vec::new(), tcx.types.u64),
 198             sym::offset | sym::arith_offset => (
 199                 1,
 200                 vec![
 201                     tcx.mk_ptr(ty::TypeAndMut { ty: param(0), mutbl: hir::Mutability::Not }),
 202                     tcx.types.isize,
 203                 ],
 204                 tcx.mk_ptr(ty::TypeAndMut { ty: param(0), mutbl: hir::Mutability::Not }),
 205             ),
 206             sym::ptr_mask => (
 207                 1,
 208                 vec![
 209                     tcx.mk_ptr(ty::TypeAndMut { ty: param(0), mutbl: hir::Mutability::Not }),
 210                     tcx.types.usize,
 211                 ],
 212                 tcx.mk_ptr(ty::TypeAndMut { ty: param(0), mutbl: hir::Mutability::Not }),
 213             ),
 214
 215             sym::copy | sym::copy_nonoverlapping => (
 216                 1,
 217                 vec![
 218                     tcx.mk_ptr(ty::TypeAndMut { ty: param(0), mutbl: hir::Mutability::Not }),
 219                     tcx.mk_ptr(ty::TypeAndMut { ty: param(0), mutbl: hir::Mutability::Mut }),
 220                     tcx.types.usize,
 221                 ],
 222                 tcx.mk_unit(),
 223             ),
 224             sym::volatile_copy_memory | sym::volatile_copy_nonoverlapping_memory => (
 225                 1,
 226                 vec![
 227                     tcx.mk_ptr(ty::TypeAndMut { ty: param(0), mutbl: hir::Mutability::Mut }),
 228                     tcx.mk_ptr(ty::TypeAndMut { ty: param(0), mutbl: hir::Mutability::Not }),
 229                     tcx.types.usize,
 230                 ],
 231                 tcx.mk_unit(),
 232             ),
 233             sym::write_bytes | sym::volatile_set_memory => (
 234                 1,
 235                 vec![
 236                     tcx.mk_ptr(ty::TypeAndMut { ty: param(0), mutbl: hir::Mutability::Mut }),
 237                     tcx.types.u8,
 238                     tcx.types.usize,
 239                 ],
 240                 tcx.mk_unit(),
 241             ),
 242             sym::sqrtf32 => (0, vec![tcx.types.f32], tcx.types.f32),
 243             sym::sqrtf64 => (0, vec![tcx.types.f64], tcx.types.f64),
 244             sym::powif32 => (0, vec![tcx.types.f32, tcx.types.i32], tcx.types.f32),
 245             sym::powif64 => (0, vec![tcx.types.f64, tcx.types.i32], tcx.types.f64),
 246             sym::sinf32 => (0, vec![tcx.types.f32], tcx.types.f32),
 247             sym::sinf64 => (0, vec![tcx.types.f64], tcx.types.f64),
 248             sym::cosf32 => (0, vec![tcx.types.f32], tcx.types.f32),
 249             sym::cosf64 => (0, vec![tcx.types.f64], tcx.types.f64),
 250             sym::powf32 => (0, vec![tcx.types.f32, tcx.types.f32], tcx.types.f32),
 251             sym::powf64 => (0, vec![tcx.types.f64, tcx.types.f64], tcx.types.f64),
 252             sym::expf32 => (0, vec![tcx.types.f32], tcx.types.f32),
 253             sym::expf64 => (0, vec![tcx.types.f64], tcx.types.f64),
 254             sym::exp2f32 => (0, vec![tcx.types.f32], tcx.types.f32),
 255             sym::exp2f64 => (0, vec![tcx.types.f64], tcx.types.f64),
 256             sym::logf32 => (0, vec![tcx.types.f32], tcx.types.f32),
 257             sym::logf64 => (0, vec![tcx.types.f64], tcx.types.f64),
 258             sym::log10f32 => (0, vec![tcx.types.f32], tcx.types.f32),
 259             sym::log10f64 => (0, vec![tcx.types.f64], tcx.types.f64),
 260             sym::log2f32 => (0, vec![tcx.types.f32], tcx.types.f32),
 261             sym::log2f64 => (0, vec![tcx.types.f64], tcx.types.f64),
 262             sym::fmaf32 => (0, vec![tcx.types.f32, tcx.types.f32, tcx.types.f32], tcx.types.f32),
 263             sym::fmaf64 => (0, vec![tcx.types.f64, tcx.types.f64, tcx.types.f64], tcx.types.f64),
 264             sym::fabsf32 => (0, vec![tcx.types.f32], tcx.types.f32),
 265             sym::fabsf64 => (0, vec![tcx.types.f64], tcx.types.f64),
 266             sym::minnumf32 => (0, vec![tcx.types.f32, tcx.types.f32], tcx.types.f32),
 267             sym::minnumf64 => (0, vec![tcx.types.f64, tcx.types.f64], tcx.types.f64),
 268             sym::maxnumf32 => (0, vec![tcx.types.f32, tcx.types.f32], tcx.types.f32),
 269             sym::maxnumf64 => (0, vec![tcx.types.f64, tcx.types.f64], tcx.types.f64),
 270             sym::copysignf32 => (0, vec![tcx.types.f32, tcx.types.f32], tcx.types.f32),
 271             sym::copysignf64 => (0, vec![tcx.types.f64, tcx.types.f64], tcx.types.f64),
 272             sym::floorf32 => (0, vec![tcx.types.f32], tcx.types.f32),
 273             sym::floorf64 => (0, vec![tcx.types.f64], tcx.types.f64),
 274             sym::ceilf32 => (0, vec![tcx.types.f32], tcx.types.f32),
 275             sym::ceilf64 => (0, vec![tcx.types.f64], tcx.types.f64),
 276             sym::truncf32 => (0, vec![tcx.types.f32], tcx.types.f32),
 277             sym::truncf64 => (0, vec![tcx.types.f64], tcx.types.f64),
 278             sym::rintf32 => (0, vec![tcx.types.f32], tcx.types.f32),
 279             sym::rintf64 => (0, vec![tcx.types.f64], tcx.types.f64),
 280             sym::nearbyintf32 => (0, vec![tcx.types.f32], tcx.types.f32),
 281             sym::nearbyintf64 => (0, vec![tcx.types.f64], tcx.types.f64),
 282             sym::roundf32 => (0, vec![tcx.types.f32], tcx.types.f32),
 283             sym::roundf64 => (0, vec![tcx.types.f64], tcx.types.f64),
 284
 285             sym::volatile_load | sym::unaligned_volatile_load => {
 286                 (1, vec![tcx.mk_imm_ptr(param(0))], param(0))
 287             }
 288             sym::volatile_store | sym::unaligned_volatile_store => {
 289                 (1, vec![tcx.mk_mut_ptr(param(0)), param(0)], tcx.mk_unit())
 290             }
 291
 292             sym::ctpop
 293             | sym::ctlz
 294             | sym::ctlz_nonzero
 295             | sym::cttz
 296             | sym::cttz_nonzero
 297             | sym::bswap
 298             | sym::bitreverse => (1, vec![param(0)], param(0)),
 299
 300             sym::add_with_overflow | sym::sub_with_overflow | sym::mul_with_overflow => {
 301                 (1, vec![param(0), param(0)], tcx.intern_tup(&[param(0), tcx.types.bool]))
 302             }
 303
 304             sym::ptr_guaranteed_cmp => {
 305                 (1, vec![tcx.mk_imm_ptr(param(0)), tcx.mk_imm_ptr(param(0))], tcx.types.u8)
 306             }
 307
 308             sym::const_allocate => {
 309                 (0, vec![tcx.types.usize, tcx.types.usize], tcx.mk_mut_ptr(tcx.types.u8))
 310             }
 311             sym::const_deallocate => (
 312                 0,
 313                 vec![tcx.mk_mut_ptr(tcx.types.u8), tcx.types.usize, tcx.types.usize],
 314                 tcx.mk_unit(),
 315             ),
 316
 317             sym::ptr_offset_from => {
 318                 (1, vec![tcx.mk_imm_ptr(param(0)), tcx.mk_imm_ptr(param(0))], tcx.types.isize)
 319             }
 320             sym::ptr_offset_from_unsigned => {
 321                 (1, vec![tcx.mk_imm_ptr(param(0)), tcx.mk_imm_ptr(param(0))], tcx.types.usize)
 322             }
 323             sym::unchecked_div | sym::unchecked_rem | sym::exact_div => {
 324                 (1, vec![param(0), param(0)], param(0))
 325             }
 326             sym::unchecked_shl | sym::unchecked_shr | sym::rotate_left | sym::rotate_right => {
 327                 (1, vec![param(0), param(0)], param(0))
 328             }
 329             sym::unchecked_add | sym::unchecked_sub | sym::unchecked_mul => {
 330                 (1, vec![param(0), param(0)], param(0))
 331             }
 332             sym::wrapping_add | sym::wrapping_sub | sym::wrapping_mul => {
 333                 (1, vec![param(0), param(0)], param(0))
 334             }
 335             sym::saturating_add | sym::saturating_sub => (1, vec![param(0), param(0)], param(0)),
 336             sym::fadd_fast | sym::fsub_fast | sym::fmul_fast | sym::fdiv_fast | sym::frem_fast => {
 337                 (1, vec![param(0), param(0)], param(0))
 338             }
 339             sym::float_to_int_unchecked => (2, vec![param(0)], param(1)),
 340
 341             sym::assume => (0, vec![tcx.types.bool], tcx.mk_unit()),
 342             sym::likely => (0, vec![tcx.types.bool], tcx.types.bool),
 343             sym::unlikely => (0, vec![tcx.types.bool], tcx.types.bool),
 344
 345             sym::discriminant_value => {
 346                 let assoc_items = tcx.associated_item_def_ids(
 347                     tcx.require_lang_item(hir::LangItem::DiscriminantKind, None),
 348                 );
 349                 let discriminant_def_id = assoc_items[0];
 350
 351                 let br = ty::BoundRegion { var: ty::BoundVar::from_u32(0), kind: ty::BrAnon(0) };
 352                 (
 353                     1,
 354                     vec![
 355                         tcx.mk_imm_ref(tcx.mk_region(ty::ReLateBound(ty::INNERMOST, br)), param(0)),
 356                     ],
 357                     tcx.mk_projection(discriminant_def_id, tcx.mk_substs([param(0).into()].iter())),
 358                 )
 359             }
 360
 361             kw::Try => {
 362                 let mut_u8 = tcx.mk_mut_ptr(tcx.types.u8);
 363                 let try_fn_ty = ty::Binder::dummy(tcx.mk_fn_sig(
 364                     iter::once(mut_u8),
 365                     tcx.mk_unit(),
 366                     false,
 367                     hir::Unsafety::Normal,
 368                     Abi::Rust,
 369                 ));
 370                 let catch_fn_ty = ty::Binder::dummy(tcx.mk_fn_sig(
 371                     [mut_u8, mut_u8].iter().cloned(),
 372                     tcx.mk_unit(),
 373                     false,
 374                     hir::Unsafety::Normal,
 375                     Abi::Rust,
 376                 ));
 377                 (
 378                     0,
 379                     vec![tcx.mk_fn_ptr(try_fn_ty), mut_u8, tcx.mk_fn_ptr(catch_fn_ty)],
 380                     tcx.types.i32,
 381                 )
 382             }
 383
 384             sym::va_start | sym::va_end => match mk_va_list_ty(hir::Mutability::Mut) {
 385                 Some((va_list_ref_ty, _)) => (0, vec![va_list_ref_ty], tcx.mk_unit()),
 386                 None => bug!("`va_list` language item needed for C-variadic intrinsics"),
 387             },
 388
 389             sym::va_copy => match mk_va_list_ty(hir::Mutability::Not) {
 390                 Some((va_list_ref_ty, va_list_ty)) => {
 391                     let va_list_ptr_ty = tcx.mk_mut_ptr(va_list_ty);
 392                     (0, vec![va_list_ptr_ty, va_list_ref_ty], tcx.mk_unit())
 393                 }
 394                 None => bug!("`va_list` language item needed for C-variadic intrinsics"),
 395             },
 396
 397             sym::va_arg => match mk_va_list_ty(hir::Mutability::Mut) {
 398                 Some((va_list_ref_ty, _)) => (1, vec![va_list_ref_ty], param(0)),
 399                 None => bug!("`va_list` language item needed for C-variadic intrinsics"),
 400             },
 401
 402             sym::nontemporal_store => (1, vec![tcx.mk_mut_ptr(param(0)), param(0)], tcx.mk_unit()),
 403
 404             sym::raw_eq => {
 405                 let br = ty::BoundRegion { var: ty::BoundVar::from_u32(0), kind: ty::BrAnon(0) };
 406                 let param_ty =
 407                     tcx.mk_imm_ref(tcx.mk_region(ty::ReLateBound(ty::INNERMOST, br)), param(0));
 408                 (1, vec![param_ty; 2], tcx.types.bool)
 409             }
 410
 411             sym::black_box => (1, vec![param(0)], param(0)),
 412
 413             sym::const_eval_select => (4, vec![param(0), param(1), param(2)], param(3)),
 414
 415             sym::vtable_size | sym::vtable_align => {
 416                 (0, vec![tcx.mk_imm_ptr(tcx.mk_unit())], tcx.types.usize)
 417             }
 418
 419             other => {
 420                 tcx.sess.emit_err(UnrecognizedIntrinsicFunction { span: it.span, name: other });
 421                 return;
 422             }
 423         };
 424         (n_tps, 0, inputs, output, unsafety)
 425     };
 426     let sig = tcx.mk_fn_sig(inputs.into_iter(), output, false, unsafety, Abi::RustIntrinsic);
 427     let sig = ty::Binder::bind_with_vars(sig, bound_vars);
 428     equate_intrinsic_type(tcx, it, n_tps, n_lts, sig)
 429 }
 430
 431 /// Type-check `extern "platform-intrinsic" { ... }` functions.
 432 pub fn check_platform_intrinsic_type(tcx: TyCtxt<'_>, it: &hir::ForeignItem<'_>) {
 433     let param = |n| {
 434         let name = Symbol::intern(&format!("P{}", n));
 435         tcx.mk_ty_param(n, name)
 436     };
 437
 438     let name = it.ident.name;
 439
 440     let (n_tps, inputs, output) = match name {
 441         sym::simd_eq | sym::simd_ne | sym::simd_lt | sym::simd_le | sym::simd_gt | sym::simd_ge => {
 442             (2, vec![param(0), param(0)], param(1))
 443         }
 444         sym::simd_add
 445         | sym::simd_sub
 446         | sym::simd_mul
 447         | sym::simd_rem
 448         | sym::simd_div
 449         | sym::simd_shl
 450         | sym::simd_shr
 451         | sym::simd_and
 452         | sym::simd_or
 453         | sym::simd_xor
 454         | sym::simd_fmin
 455         | sym::simd_fmax
 456         | sym::simd_fpow
 457         | sym::simd_saturating_add
 458         | sym::simd_saturating_sub => (1, vec![param(0), param(0)], param(0)),
 459         sym::simd_arith_offset => (2, vec![param(0), param(1)], param(0)),
 460         sym::simd_neg
 461         | sym::simd_fsqrt
 462         | sym::simd_fsin
 463         | sym::simd_fcos
 464         | sym::simd_fexp
 465         | sym::simd_fexp2
 466         | sym::simd_flog2
 467         | sym::simd_flog10
 468         | sym::simd_flog
 469         | sym::simd_fabs
 470         | sym::simd_ceil
 471         | sym::simd_floor
 472         | sym::simd_round
 473         | sym::simd_trunc => (1, vec![param(0)], param(0)),
 474         sym::simd_fpowi => (1, vec![param(0), tcx.types.i32], param(0)),
 475         sym::simd_fma => (1, vec![param(0), param(0), param(0)], param(0)),
 476         sym::simd_gather => (3, vec![param(0), param(1), param(2)], param(0)),
 477         sym::simd_scatter => (3, vec![param(0), param(1), param(2)], tcx.mk_unit()),
 478         sym::simd_insert => (2, vec![param(0), tcx.types.u32, param(1)], param(0)),
 479         sym::simd_extract => (2, vec![param(0), tcx.types.u32], param(1)),
 480         sym::simd_cast
 481         | sym::simd_as
 482         | sym::simd_cast_ptr
 483         | sym::simd_expose_addr
 484         | sym::simd_from_exposed_addr => (2, vec![param(0)], param(1)),
 485         sym::simd_bitmask => (2, vec![param(0)], param(1)),
 486         sym::simd_select | sym::simd_select_bitmask => {
 487             (2, vec![param(0), param(1), param(1)], param(1))
 488         }
 489         sym::simd_reduce_all | sym::simd_reduce_any => (1, vec![param(0)], tcx.types.bool),
 490         sym::simd_reduce_add_ordered | sym::simd_reduce_mul_ordered => {
 491             (2, vec![param(0), param(1)], param(1))
 492         }
 493         sym::simd_reduce_add_unordered
 494         | sym::simd_reduce_mul_unordered
 495         | sym::simd_reduce_and
 496         | sym::simd_reduce_or
 497         | sym::simd_reduce_xor
 498         | sym::simd_reduce_min
 499         | sym::simd_reduce_max
 500         | sym::simd_reduce_min_nanless
 501         | sym::simd_reduce_max_nanless => (2, vec![param(0)], param(1)),
 502         sym::simd_shuffle => (3, vec![param(0), param(0), param(1)], param(2)),
 503         name if name.as_str().starts_with("simd_shuffle") => {
 504             match name.as_str()["simd_shuffle".len()..].parse() {
 505                 Ok(n) => {
 506                     let params = vec![param(0), param(0), tcx.mk_array(tcx.types.u32, n)];
 507                     (2, params, param(1))
 508                 }
 509                 Err(_) => {
 510                     let msg =
 511                         format!("unrecognized platform-specific intrinsic function: `{name}`");
 512                     tcx.sess.struct_span_err(it.span, &msg).emit();
 513                     return;
 514                 }
 515             }
 516         }
 517         _ => {
 518             let msg = format!("unrecognized platform-specific intrinsic function: `{name}`");
 519             tcx.sess.struct_span_err(it.span, &msg).emit();
 520             return;
 521         }
 522     };
 523
 524     let sig = tcx.mk_fn_sig(
 525         inputs.into_iter(),
 526         output,
 527         false,
 528         hir::Unsafety::Unsafe,
 529         Abi::PlatformIntrinsic,
 530     );
 531     let sig = ty::Binder::dummy(sig);
 532     equate_intrinsic_type(tcx, it, n_tps, 0, sig)
 533 }