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Rollup merge of #97739 - a2aaron:let_underscore, r=estebank
[rust.git] / 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_eq
99         | sym::ptr_guaranteed_ne
100         | sym::minnumf32
101         | sym::minnumf64
102         | sym::maxnumf32
103         | sym::rustc_peek
104         | sym::maxnumf64
105         | sym::type_name
106         | sym::forget
107         | sym::black_box
108         | sym::variant_count
109         | sym::ptr_mask => hir::Unsafety::Normal,
110         _ => hir::Unsafety::Unsafe,
111     }
112 }
113
114 /// Remember to add all intrinsics here, in `compiler/rustc_codegen_llvm/src/intrinsic.rs`,
115 /// and in `library/core/src/intrinsics.rs`.
116 pub fn check_intrinsic_type(tcx: TyCtxt<'_>, it: &hir::ForeignItem<'_>) {
117     let param = |n| tcx.mk_ty_param(n, Symbol::intern(&format!("P{}", n)));
118     let intrinsic_name = tcx.item_name(it.def_id.to_def_id());
119     let name_str = intrinsic_name.as_str();
120
121     let bound_vars = tcx.mk_bound_variable_kinds(
122         [ty::BoundVariableKind::Region(ty::BrAnon(0)), ty::BoundVariableKind::Region(ty::BrEnv)]
123             .iter()
124             .copied(),
125     );
126     let mk_va_list_ty = |mutbl| {
127         tcx.lang_items().va_list().map(|did| {
128             let region = tcx.mk_region(ty::ReLateBound(
129                 ty::INNERMOST,
130                 ty::BoundRegion { var: ty::BoundVar::from_u32(0), kind: ty::BrAnon(0) },
131             ));
132             let env_region = tcx.mk_region(ty::ReLateBound(
133                 ty::INNERMOST,
134                 ty::BoundRegion { var: ty::BoundVar::from_u32(1), kind: ty::BrEnv },
135             ));
136             let va_list_ty = tcx.bound_type_of(did).subst(tcx, &[region.into()]);
137             (tcx.mk_ref(env_region, ty::TypeAndMut { ty: va_list_ty, mutbl }), va_list_ty)
138         })
139     };
140
141     let (n_tps, n_lts, inputs, output, unsafety) = if name_str.starts_with("atomic_") {
142         let split: Vec<&str> = name_str.split('_').collect();
143         assert!(split.len() >= 2, "Atomic intrinsic in an incorrect format");
144
145         //We only care about the operation here
146         let (n_tps, inputs, output) = match split[1] {
147             "cxchg" | "cxchgweak" => (
148                 1,
149                 vec![tcx.mk_mut_ptr(param(0)), param(0), param(0)],
150                 tcx.intern_tup(&[param(0), tcx.types.bool]),
151             ),
152             "load" => (1, vec![tcx.mk_imm_ptr(param(0))], param(0)),
153             "store" => (1, vec![tcx.mk_mut_ptr(param(0)), param(0)], tcx.mk_unit()),
154
155             "xchg" | "xadd" | "xsub" | "and" | "nand" | "or" | "xor" | "max" | "min" | "umax"
156             | "umin" => (1, vec![tcx.mk_mut_ptr(param(0)), param(0)], param(0)),
157             "fence" | "singlethreadfence" => (0, Vec::new(), tcx.mk_unit()),
158             op => {
159                 tcx.sess.emit_err(UnrecognizedAtomicOperation { span: it.span, op });
160                 return;
161             }
162         };
163         (n_tps, 0, inputs, output, hir::Unsafety::Unsafe)
164     } else {
165         let unsafety = intrinsic_operation_unsafety(intrinsic_name);
166         let (n_tps, inputs, output) = match intrinsic_name {
167             sym::abort => (0, Vec::new(), tcx.types.never),
168             sym::unreachable => (0, Vec::new(), tcx.types.never),
169             sym::breakpoint => (0, Vec::new(), tcx.mk_unit()),
170             sym::size_of | sym::pref_align_of | sym::min_align_of | sym::variant_count => {
171                 (1, Vec::new(), tcx.types.usize)
172             }
173             sym::size_of_val | sym::min_align_of_val => {
174                 (1, vec![tcx.mk_imm_ptr(param(0))], tcx.types.usize)
175             }
176             sym::rustc_peek => (1, vec![param(0)], param(0)),
177             sym::caller_location => (0, vec![], tcx.caller_location_ty()),
178             sym::assert_inhabited | sym::assert_zero_valid | sym::assert_uninit_valid => {
179                 (1, Vec::new(), tcx.mk_unit())
180             }
181             sym::forget => (1, vec![param(0)], tcx.mk_unit()),
182             sym::transmute => (2, vec![param(0)], param(1)),
183             sym::prefetch_read_data
184             | sym::prefetch_write_data
185             | sym::prefetch_read_instruction
186             | sym::prefetch_write_instruction => (
187                 1,
188                 vec![
189                     tcx.mk_ptr(ty::TypeAndMut { ty: param(0), mutbl: hir::Mutability::Not }),
190                     tcx.types.i32,
191                 ],
192                 tcx.mk_unit(),
193             ),
194             sym::drop_in_place => (1, vec![tcx.mk_mut_ptr(param(0))], tcx.mk_unit()),
195             sym::needs_drop => (1, Vec::new(), tcx.types.bool),
196
197             sym::type_name => (1, Vec::new(), tcx.mk_static_str()),
198             sym::type_id => (1, Vec::new(), tcx.types.u64),
199             sym::offset | sym::arith_offset => (
200                 1,
201                 vec![
202                     tcx.mk_ptr(ty::TypeAndMut { ty: param(0), mutbl: hir::Mutability::Not }),
203                     tcx.types.isize,
204                 ],
205                 tcx.mk_ptr(ty::TypeAndMut { ty: param(0), mutbl: hir::Mutability::Not }),
206             ),
207             sym::ptr_mask => (
208                 1,
209                 vec![
210                     tcx.mk_ptr(ty::TypeAndMut { ty: param(0), mutbl: hir::Mutability::Not }),
211                     tcx.types.usize,
212                 ],
213                 tcx.mk_ptr(ty::TypeAndMut { ty: param(0), mutbl: hir::Mutability::Not }),
214             ),
215
216             sym::copy | sym::copy_nonoverlapping => (
217                 1,
218                 vec![
219                     tcx.mk_ptr(ty::TypeAndMut { ty: param(0), mutbl: hir::Mutability::Not }),
220                     tcx.mk_ptr(ty::TypeAndMut { ty: param(0), mutbl: hir::Mutability::Mut }),
221                     tcx.types.usize,
222                 ],
223                 tcx.mk_unit(),
224             ),
225             sym::volatile_copy_memory | sym::volatile_copy_nonoverlapping_memory => (
226                 1,
227                 vec![
228                     tcx.mk_ptr(ty::TypeAndMut { ty: param(0), mutbl: hir::Mutability::Mut }),
229                     tcx.mk_ptr(ty::TypeAndMut { ty: param(0), mutbl: hir::Mutability::Not }),
230                     tcx.types.usize,
231                 ],
232                 tcx.mk_unit(),
233             ),
234             sym::write_bytes | sym::volatile_set_memory => (
235                 1,
236                 vec![
237                     tcx.mk_ptr(ty::TypeAndMut { ty: param(0), mutbl: hir::Mutability::Mut }),
238                     tcx.types.u8,
239                     tcx.types.usize,
240                 ],
241                 tcx.mk_unit(),
242             ),
243             sym::sqrtf32 => (0, vec![tcx.types.f32], tcx.types.f32),
244             sym::sqrtf64 => (0, vec![tcx.types.f64], tcx.types.f64),
245             sym::powif32 => (0, vec![tcx.types.f32, tcx.types.i32], tcx.types.f32),
246             sym::powif64 => (0, vec![tcx.types.f64, tcx.types.i32], tcx.types.f64),
247             sym::sinf32 => (0, vec![tcx.types.f32], tcx.types.f32),
248             sym::sinf64 => (0, vec![tcx.types.f64], tcx.types.f64),
249             sym::cosf32 => (0, vec![tcx.types.f32], tcx.types.f32),
250             sym::cosf64 => (0, vec![tcx.types.f64], tcx.types.f64),
251             sym::powf32 => (0, vec![tcx.types.f32, tcx.types.f32], tcx.types.f32),
252             sym::powf64 => (0, vec![tcx.types.f64, tcx.types.f64], tcx.types.f64),
253             sym::expf32 => (0, vec![tcx.types.f32], tcx.types.f32),
254             sym::expf64 => (0, vec![tcx.types.f64], tcx.types.f64),
255             sym::exp2f32 => (0, vec![tcx.types.f32], tcx.types.f32),
256             sym::exp2f64 => (0, vec![tcx.types.f64], tcx.types.f64),
257             sym::logf32 => (0, vec![tcx.types.f32], tcx.types.f32),
258             sym::logf64 => (0, vec![tcx.types.f64], tcx.types.f64),
259             sym::log10f32 => (0, vec![tcx.types.f32], tcx.types.f32),
260             sym::log10f64 => (0, vec![tcx.types.f64], tcx.types.f64),
261             sym::log2f32 => (0, vec![tcx.types.f32], tcx.types.f32),
262             sym::log2f64 => (0, vec![tcx.types.f64], tcx.types.f64),
263             sym::fmaf32 => (0, vec![tcx.types.f32, tcx.types.f32, tcx.types.f32], tcx.types.f32),
264             sym::fmaf64 => (0, vec![tcx.types.f64, tcx.types.f64, tcx.types.f64], tcx.types.f64),
265             sym::fabsf32 => (0, vec![tcx.types.f32], tcx.types.f32),
266             sym::fabsf64 => (0, vec![tcx.types.f64], tcx.types.f64),
267             sym::minnumf32 => (0, vec![tcx.types.f32, tcx.types.f32], tcx.types.f32),
268             sym::minnumf64 => (0, vec![tcx.types.f64, tcx.types.f64], tcx.types.f64),
269             sym::maxnumf32 => (0, vec![tcx.types.f32, tcx.types.f32], tcx.types.f32),
270             sym::maxnumf64 => (0, vec![tcx.types.f64, tcx.types.f64], tcx.types.f64),
271             sym::copysignf32 => (0, vec![tcx.types.f32, tcx.types.f32], tcx.types.f32),
272             sym::copysignf64 => (0, vec![tcx.types.f64, tcx.types.f64], tcx.types.f64),
273             sym::floorf32 => (0, vec![tcx.types.f32], tcx.types.f32),
274             sym::floorf64 => (0, vec![tcx.types.f64], tcx.types.f64),
275             sym::ceilf32 => (0, vec![tcx.types.f32], tcx.types.f32),
276             sym::ceilf64 => (0, vec![tcx.types.f64], tcx.types.f64),
277             sym::truncf32 => (0, vec![tcx.types.f32], tcx.types.f32),
278             sym::truncf64 => (0, vec![tcx.types.f64], tcx.types.f64),
279             sym::rintf32 => (0, vec![tcx.types.f32], tcx.types.f32),
280             sym::rintf64 => (0, vec![tcx.types.f64], tcx.types.f64),
281             sym::nearbyintf32 => (0, vec![tcx.types.f32], tcx.types.f32),
282             sym::nearbyintf64 => (0, vec![tcx.types.f64], tcx.types.f64),
283             sym::roundf32 => (0, vec![tcx.types.f32], tcx.types.f32),
284             sym::roundf64 => (0, vec![tcx.types.f64], tcx.types.f64),
285
286             sym::volatile_load | sym::unaligned_volatile_load => {
287                 (1, vec![tcx.mk_imm_ptr(param(0))], param(0))
288             }
289             sym::volatile_store | sym::unaligned_volatile_store => {
290                 (1, vec![tcx.mk_mut_ptr(param(0)), param(0)], tcx.mk_unit())
291             }
292
293             sym::ctpop
294             | sym::ctlz
295             | sym::ctlz_nonzero
296             | sym::cttz
297             | sym::cttz_nonzero
298             | sym::bswap
299             | sym::bitreverse => (1, vec![param(0)], param(0)),
300
301             sym::add_with_overflow | sym::sub_with_overflow | sym::mul_with_overflow => {
302                 (1, vec![param(0), param(0)], tcx.intern_tup(&[param(0), tcx.types.bool]))
303             }
304
305             sym::ptr_guaranteed_eq | sym::ptr_guaranteed_ne => {
306                 (1, vec![tcx.mk_imm_ptr(param(0)), tcx.mk_imm_ptr(param(0))], tcx.types.bool)
307             }
308
309             sym::const_allocate => {
310                 (0, vec![tcx.types.usize, tcx.types.usize], tcx.mk_mut_ptr(tcx.types.u8))
311             }
312             sym::const_deallocate => (
313                 0,
314                 vec![tcx.mk_mut_ptr(tcx.types.u8), tcx.types.usize, tcx.types.usize],
315                 tcx.mk_unit(),
316             ),
317
318             sym::ptr_offset_from => {
319                 (1, vec![tcx.mk_imm_ptr(param(0)), tcx.mk_imm_ptr(param(0))], tcx.types.isize)
320             }
321             sym::ptr_offset_from_unsigned => {
322                 (1, vec![tcx.mk_imm_ptr(param(0)), tcx.mk_imm_ptr(param(0))], tcx.types.usize)
323             }
324             sym::unchecked_div | sym::unchecked_rem | sym::exact_div => {
325                 (1, vec![param(0), param(0)], param(0))
326             }
327             sym::unchecked_shl | sym::unchecked_shr | sym::rotate_left | sym::rotate_right => {
328                 (1, vec![param(0), param(0)], param(0))
329             }
330             sym::unchecked_add | sym::unchecked_sub | sym::unchecked_mul => {
331                 (1, vec![param(0), param(0)], param(0))
332             }
333             sym::wrapping_add | sym::wrapping_sub | sym::wrapping_mul => {
334                 (1, vec![param(0), param(0)], param(0))
335             }
336             sym::saturating_add | sym::saturating_sub => (1, vec![param(0), param(0)], param(0)),
337             sym::fadd_fast | sym::fsub_fast | sym::fmul_fast | sym::fdiv_fast | sym::frem_fast => {
338                 (1, vec![param(0), param(0)], param(0))
339             }
340             sym::float_to_int_unchecked => (2, vec![param(0)], param(1)),
341
342             sym::assume => (0, vec![tcx.types.bool], tcx.mk_unit()),
343             sym::likely => (0, vec![tcx.types.bool], tcx.types.bool),
344             sym::unlikely => (0, vec![tcx.types.bool], tcx.types.bool),
345
346             sym::discriminant_value => {
347                 let assoc_items = tcx.associated_item_def_ids(
348                     tcx.require_lang_item(hir::LangItem::DiscriminantKind, None),
349                 );
350                 let discriminant_def_id = assoc_items[0];
351
352                 let br = ty::BoundRegion { var: ty::BoundVar::from_u32(0), kind: ty::BrAnon(0) };
353                 (
354                     1,
355                     vec![
356                         tcx.mk_imm_ref(tcx.mk_region(ty::ReLateBound(ty::INNERMOST, br)), param(0)),
357                     ],
358                     tcx.mk_projection(discriminant_def_id, tcx.mk_substs([param(0).into()].iter())),
359                 )
360             }
361
362             kw::Try => {
363                 let mut_u8 = tcx.mk_mut_ptr(tcx.types.u8);
364                 let try_fn_ty = ty::Binder::dummy(tcx.mk_fn_sig(
365                     iter::once(mut_u8),
366                     tcx.mk_unit(),
367                     false,
368                     hir::Unsafety::Normal,
369                     Abi::Rust,
370                 ));
371                 let catch_fn_ty = ty::Binder::dummy(tcx.mk_fn_sig(
372                     [mut_u8, mut_u8].iter().cloned(),
373                     tcx.mk_unit(),
374                     false,
375                     hir::Unsafety::Normal,
376                     Abi::Rust,
377                 ));
378                 (
379                     0,
380                     vec![tcx.mk_fn_ptr(try_fn_ty), mut_u8, tcx.mk_fn_ptr(catch_fn_ty)],
381                     tcx.types.i32,
382                 )
383             }
384
385             sym::va_start | sym::va_end => match mk_va_list_ty(hir::Mutability::Mut) {
386                 Some((va_list_ref_ty, _)) => (0, vec![va_list_ref_ty], tcx.mk_unit()),
387                 None => bug!("`va_list` language item needed for C-variadic intrinsics"),
388             },
389
390             sym::va_copy => match mk_va_list_ty(hir::Mutability::Not) {
391                 Some((va_list_ref_ty, va_list_ty)) => {
392                     let va_list_ptr_ty = tcx.mk_mut_ptr(va_list_ty);
393                     (0, vec![va_list_ptr_ty, va_list_ref_ty], tcx.mk_unit())
394                 }
395                 None => bug!("`va_list` language item needed for C-variadic intrinsics"),
396             },
397
398             sym::va_arg => match mk_va_list_ty(hir::Mutability::Mut) {
399                 Some((va_list_ref_ty, _)) => (1, vec![va_list_ref_ty], param(0)),
400                 None => bug!("`va_list` language item needed for C-variadic intrinsics"),
401             },
402
403             sym::nontemporal_store => (1, vec![tcx.mk_mut_ptr(param(0)), param(0)], tcx.mk_unit()),
404
405             sym::raw_eq => {
406                 let br = ty::BoundRegion { var: ty::BoundVar::from_u32(0), kind: ty::BrAnon(0) };
407                 let param_ty =
408                     tcx.mk_imm_ref(tcx.mk_region(ty::ReLateBound(ty::INNERMOST, br)), param(0));
409                 (1, vec![param_ty; 2], tcx.types.bool)
410             }
411
412             sym::black_box => (1, vec![param(0)], param(0)),
413
414             sym::const_eval_select => (4, vec![param(0), param(1), param(2)], param(3)),
415
416             sym::vtable_size | sym::vtable_align => {
417                 (0, vec![tcx.mk_imm_ptr(tcx.mk_unit())], tcx.types.usize)
418             }
419
420             other => {
421                 tcx.sess.emit_err(UnrecognizedIntrinsicFunction { span: it.span, name: other });
422                 return;
423             }
424         };
425         (n_tps, 0, inputs, output, unsafety)
426     };
427     let sig = tcx.mk_fn_sig(inputs.into_iter(), output, false, unsafety, Abi::RustIntrinsic);
428     let sig = ty::Binder::bind_with_vars(sig, bound_vars);
429     equate_intrinsic_type(tcx, it, n_tps, n_lts, sig)
430 }
431
432 /// Type-check `extern "platform-intrinsic" { ... }` functions.
433 pub fn check_platform_intrinsic_type(tcx: TyCtxt<'_>, it: &hir::ForeignItem<'_>) {
434     let param = |n| {
435         let name = Symbol::intern(&format!("P{}", n));
436         tcx.mk_ty_param(n, name)
437     };
438
439     let name = it.ident.name;
440
441     let (n_tps, inputs, output) = match name {
442         sym::simd_eq | sym::simd_ne | sym::simd_lt | sym::simd_le | sym::simd_gt | sym::simd_ge => {
443             (2, vec![param(0), param(0)], param(1))
444         }
445         sym::simd_add
446         | sym::simd_sub
447         | sym::simd_mul
448         | sym::simd_rem
449         | sym::simd_div
450         | sym::simd_shl
451         | sym::simd_shr
452         | sym::simd_and
453         | sym::simd_or
454         | sym::simd_xor
455         | sym::simd_fmin
456         | sym::simd_fmax
457         | sym::simd_fpow
458         | sym::simd_saturating_add
459         | sym::simd_saturating_sub => (1, vec![param(0), param(0)], param(0)),
460         sym::simd_arith_offset => (2, vec![param(0), param(1)], param(0)),
461         sym::simd_neg
462         | sym::simd_fsqrt
463         | sym::simd_fsin
464         | sym::simd_fcos
465         | sym::simd_fexp
466         | sym::simd_fexp2
467         | sym::simd_flog2
468         | sym::simd_flog10
469         | sym::simd_flog
470         | sym::simd_fabs
471         | sym::simd_ceil
472         | sym::simd_floor
473         | sym::simd_round
474         | sym::simd_trunc => (1, vec![param(0)], param(0)),
475         sym::simd_fpowi => (1, vec![param(0), tcx.types.i32], param(0)),
476         sym::simd_fma => (1, vec![param(0), param(0), param(0)], param(0)),
477         sym::simd_gather => (3, vec![param(0), param(1), param(2)], param(0)),
478         sym::simd_scatter => (3, vec![param(0), param(1), param(2)], tcx.mk_unit()),
479         sym::simd_insert => (2, vec![param(0), tcx.types.u32, param(1)], param(0)),
480         sym::simd_extract => (2, vec![param(0), tcx.types.u32], param(1)),
481         sym::simd_cast | sym::simd_as => (2, vec![param(0)], param(1)),
482         sym::simd_bitmask => (2, vec![param(0)], param(1)),
483         sym::simd_select | sym::simd_select_bitmask => {
484             (2, vec![param(0), param(1), param(1)], param(1))
485         }
486         sym::simd_reduce_all | sym::simd_reduce_any => (1, vec![param(0)], tcx.types.bool),
487         sym::simd_reduce_add_ordered | sym::simd_reduce_mul_ordered => {
488             (2, vec![param(0), param(1)], param(1))
489         }
490         sym::simd_reduce_add_unordered
491         | sym::simd_reduce_mul_unordered
492         | sym::simd_reduce_and
493         | sym::simd_reduce_or
494         | sym::simd_reduce_xor
495         | sym::simd_reduce_min
496         | sym::simd_reduce_max
497         | sym::simd_reduce_min_nanless
498         | sym::simd_reduce_max_nanless => (2, vec![param(0)], param(1)),
499         sym::simd_shuffle => (3, vec![param(0), param(0), param(1)], param(2)),
500         name if name.as_str().starts_with("simd_shuffle") => {
501             match name.as_str()["simd_shuffle".len()..].parse() {
502                 Ok(n) => {
503                     let params = vec![param(0), param(0), tcx.mk_array(tcx.types.u32, n)];
504                     (2, params, param(1))
505                 }
506                 Err(_) => {
507                     let msg =
508                         format!("unrecognized platform-specific intrinsic function: `{name}`");
509                     tcx.sess.struct_span_err(it.span, &msg).emit();
510                     return;
511                 }
512             }
513         }
514         _ => {
515             let msg = format!("unrecognized platform-specific intrinsic function: `{name}`");
516             tcx.sess.struct_span_err(it.span, &msg).emit();
517             return;
518         }
519     };
520
521     let sig = tcx.mk_fn_sig(
522         inputs.into_iter(),
523         output,
524         false,
525         hir::Unsafety::Unsafe,
526         Abi::PlatformIntrinsic,
527     );
528     let sig = ty::Binder::dummy(sig);
529     equate_intrinsic_type(tcx, it, n_tps, 0, sig)
530 }