Auto merge of rust-lang#121516 - RalfJung:platform-intrinsics-begone, r=oli-obk

remove platform-intrinsics ABI; make SIMD intrinsics be regular intrinsics

`@Amanieu` `@workingjubilee` I don't think there is any reason these need to be "special"? The [original RFC](https://rust-lang.github.io/rfcs/1199-simd-infrastructure.html) indicated eventually making them stable, but I think that is no longer the plan, so seems to me like we can clean this up a bit.

Blocked on rust-lang/stdarch#1538, rust-lang#121542.

Author: bors

compiler/rustc_codegen_cranelift/example/float-minmax-pass.rs

@@ -4,17 +4,14 @@
 
 // Test that the simd_f{min,max} intrinsics produce the correct results.
 
-#![feature(repr_simd, platform_intrinsics)]
+#![feature(repr_simd, core_intrinsics)]
 #![allow(non_camel_case_types)]
 
 #[repr(simd)]
 #[derive(Copy, Clone, PartialEq, Debug)]
 struct f32x4(pub f32, pub f32, pub f32, pub f32);
 
-extern "platform-intrinsic" {
-    fn simd_fmin<T>(x: T, y: T) -> T;
-    fn simd_fmax<T>(x: T, y: T) -> T;
-}
+use std::intrinsics::simd::*;
 
 fn main() {
     let x = f32x4(1.0, 2.0, 3.0, 4.0);

compiler/rustc_error_codes/src/error_codes/E0511.md

@@ -3,9 +3,9 @@ Invalid monomorphization of an intrinsic function was used.
 Erroneous code example:
 
 ```compile_fail,E0511
-#![feature(platform_intrinsics)]
+#![feature(intrinsics)]
 
-extern "platform-intrinsic" {
+extern "rust-intrinsic" {
     fn simd_add<T>(a: T, b: T) -> T;
 }
 
@@ -19,13 +19,13 @@ The generic type has to be a SIMD type. Example:
 
 ```
 #![feature(repr_simd)]
-#![feature(platform_intrinsics)]
+#![feature(intrinsics)]
 
 #[repr(simd)]
 #[derive(Copy, Clone)]
 struct i32x2(i32, i32);
 
-extern "platform-intrinsic" {
+extern "rust-intrinsic" {
     fn simd_add<T>(a: T, b: T) -> T;
 }
 

compiler/rustc_feature/src/removed.rs

@@ -156,6 +156,9 @@ declare_features! (
      Some("removed in favor of `#![feature(marker_trait_attr)]`")),
     (removed, panic_implementation, "1.28.0", Some(44489),
      Some("subsumed by `#[panic_handler]`")),
+    /// Allows `extern "platform-intrinsic" { ... }`.
+    (removed, platform_intrinsics, "1.4.0", Some(27731),
+     Some("SIMD intrinsics use the regular intrinsics ABI now")),
     /// Allows using `#![plugin(myplugin)]`.
     (removed, plugin, "1.75.0", Some(29597),
      Some("plugins are no longer supported")),

compiler/rustc_feature/src/unstable.rs

@@ -259,8 +259,6 @@ declare_features! (
     (internal, needs_panic_runtime, "1.10.0", Some(32837)),
     /// Allows using the `#![panic_runtime]` attribute.
     (internal, panic_runtime, "1.10.0", Some(32837)),
-    /// Allows `extern "platform-intrinsic" { ... }`.
-    (internal, platform_intrinsics, "1.4.0", Some(27731)),
     /// Allows using `#[rustc_allow_const_fn_unstable]`.
     /// This is an attribute on `const fn` for the same
     /// purpose as `#[allow_internal_unstable]`.

compiler/rustc_hir_analysis/src/check/check.rs

@@ -612,17 +612,6 @@ pub(crate) fn check_item_type(tcx: TyCtxt<'_>, def_id: LocalDefId) {
                     }
                 }
 
-                Abi::PlatformIntrinsic => {
-                    for item in items {
-                        intrinsic::check_platform_intrinsic_type(
-                            tcx,
-                            item.id.owner_id.def_id,
-                            item.span,
-                            item.ident.name,
-                        );
-                    }
-                }
-
                 _ => {
                     for item in items {
                         let def_id = item.id.owner_id.def_id;

compiler/rustc_hir_analysis/src/check/intrinsic.rs

@@ -510,6 +510,77 @@ pub fn check_intrinsic_type(
 
             sym::debug_assertions => (0, 1, Vec::new(), tcx.types.bool),
 
+            sym::simd_eq
+            | sym::simd_ne
+            | sym::simd_lt
+            | sym::simd_le
+            | sym::simd_gt
+            | sym::simd_ge => (2, 0, vec![param(0), param(0)], param(1)),
+            sym::simd_add
+            | sym::simd_sub
+            | sym::simd_mul
+            | sym::simd_rem
+            | sym::simd_div
+            | sym::simd_shl
+            | sym::simd_shr
+            | sym::simd_and
+            | sym::simd_or
+            | sym::simd_xor
+            | sym::simd_fmin
+            | sym::simd_fmax
+            | sym::simd_fpow
+            | sym::simd_saturating_add
+            | sym::simd_saturating_sub => (1, 0, vec![param(0), param(0)], param(0)),
+            sym::simd_arith_offset => (2, 0, vec![param(0), param(1)], param(0)),
+            sym::simd_neg
+            | sym::simd_bswap
+            | sym::simd_bitreverse
+            | sym::simd_ctlz
+            | sym::simd_cttz
+            | sym::simd_fsqrt
+            | sym::simd_fsin
+            | sym::simd_fcos
+            | sym::simd_fexp
+            | sym::simd_fexp2
+            | sym::simd_flog2
+            | sym::simd_flog10
+            | sym::simd_flog
+            | sym::simd_fabs
+            | sym::simd_ceil
+            | sym::simd_floor
+            | sym::simd_round
+            | sym::simd_trunc => (1, 0, vec![param(0)], param(0)),
+            sym::simd_fpowi => (1, 0, vec![param(0), tcx.types.i32], param(0)),
+            sym::simd_fma => (1, 0, vec![param(0), param(0), param(0)], param(0)),
+            sym::simd_gather => (3, 0, vec![param(0), param(1), param(2)], param(0)),
+            sym::simd_masked_load => (3, 0, vec![param(0), param(1), param(2)], param(2)),
+            sym::simd_masked_store => (3, 0, vec![param(0), param(1), param(2)], Ty::new_unit(tcx)),
+            sym::simd_scatter => (3, 0, vec![param(0), param(1), param(2)], Ty::new_unit(tcx)),
+            sym::simd_insert => (2, 0, vec![param(0), tcx.types.u32, param(1)], param(0)),
+            sym::simd_extract => (2, 0, vec![param(0), tcx.types.u32], param(1)),
+            sym::simd_cast
+            | sym::simd_as
+            | sym::simd_cast_ptr
+            | sym::simd_expose_addr
+            | sym::simd_from_exposed_addr => (2, 0, vec![param(0)], param(1)),
+            sym::simd_bitmask => (2, 0, vec![param(0)], param(1)),
+            sym::simd_select | sym::simd_select_bitmask => {
+                (2, 0, vec![param(0), param(1), param(1)], param(1))
+            }
+            sym::simd_reduce_all | sym::simd_reduce_any => (1, 0, vec![param(0)], tcx.types.bool),
+            sym::simd_reduce_add_ordered | sym::simd_reduce_mul_ordered => {
+                (2, 0, vec![param(0), param(1)], param(1))
+            }
+            sym::simd_reduce_add_unordered
+            | sym::simd_reduce_mul_unordered
+            | sym::simd_reduce_and
+            | sym::simd_reduce_or
+            | sym::simd_reduce_xor
+            | sym::simd_reduce_min
+            | sym::simd_reduce_max => (2, 0, vec![param(0)], param(1)),
+            sym::simd_shuffle => (3, 0, vec![param(0), param(0), param(1)], param(2)),
+            sym::simd_shuffle_generic => (2, 1, vec![param(0), param(0)], param(1)),
+
             other => {
                 tcx.dcx().emit_err(UnrecognizedIntrinsicFunction { span, name: other });
                 return;
@@ -521,102 +592,3 @@ pub fn check_intrinsic_type(
     let sig = ty::Binder::bind_with_vars(sig, bound_vars);
     equate_intrinsic_type(tcx, span, intrinsic_id, n_tps, n_lts, n_cts, sig)
 }
-
-/// Type-check `extern "platform-intrinsic" { ... }` functions.
-pub fn check_platform_intrinsic_type(
-    tcx: TyCtxt<'_>,
-    intrinsic_id: LocalDefId,
-    span: Span,
-    name: Symbol,
-) {
-    let generics = tcx.generics_of(intrinsic_id);
-    let param = |n| {
-        if let Some(&ty::GenericParamDef {
-            name, kind: ty::GenericParamDefKind::Type { .. }, ..
-        }) = generics.opt_param_at(n as usize, tcx)
-        {
-            Ty::new_param(tcx, n, name)
-        } else {
-            Ty::new_error_with_message(tcx, span, "expected param")
-        }
-    };
-
-    let (n_tps, n_cts, inputs, output) = match name {
-        sym::simd_eq | sym::simd_ne | sym::simd_lt | sym::simd_le | sym::simd_gt | sym::simd_ge => {
-            (2, 0, vec![param(0), param(0)], param(1))
-        }
-        sym::simd_add
-        | sym::simd_sub
-        | sym::simd_mul
-        | sym::simd_rem
-        | sym::simd_div
-        | sym::simd_shl
-        | sym::simd_shr
-        | sym::simd_and
-        | sym::simd_or
-        | sym::simd_xor
-        | sym::simd_fmin
-        | sym::simd_fmax
-        | sym::simd_fpow
-        | sym::simd_saturating_add
-        | sym::simd_saturating_sub => (1, 0, vec![param(0), param(0)], param(0)),
-        sym::simd_arith_offset => (2, 0, vec![param(0), param(1)], param(0)),
-        sym::simd_neg
-        | sym::simd_bswap
-        | sym::simd_bitreverse
-        | sym::simd_ctlz
-        | sym::simd_cttz
-        | sym::simd_fsqrt
-        | sym::simd_fsin
-        | sym::simd_fcos
-        | sym::simd_fexp
-        | sym::simd_fexp2
-        | sym::simd_flog2
-        | sym::simd_flog10
-        | sym::simd_flog
-        | sym::simd_fabs
-        | sym::simd_ceil
-        | sym::simd_floor
-        | sym::simd_round
-        | sym::simd_trunc => (1, 0, vec![param(0)], param(0)),
-        sym::simd_fpowi => (1, 0, vec![param(0), tcx.types.i32], param(0)),
-        sym::simd_fma => (1, 0, vec![param(0), param(0), param(0)], param(0)),
-        sym::simd_gather => (3, 0, vec![param(0), param(1), param(2)], param(0)),
-        sym::simd_masked_load => (3, 0, vec![param(0), param(1), param(2)], param(2)),
-        sym::simd_masked_store => (3, 0, vec![param(0), param(1), param(2)], Ty::new_unit(tcx)),
-        sym::simd_scatter => (3, 0, vec![param(0), param(1), param(2)], Ty::new_unit(tcx)),
-        sym::simd_insert => (2, 0, vec![param(0), tcx.types.u32, param(1)], param(0)),
-        sym::simd_extract => (2, 0, vec![param(0), tcx.types.u32], param(1)),
-        sym::simd_cast
-        | sym::simd_as
-        | sym::simd_cast_ptr
-        | sym::simd_expose_addr
-        | sym::simd_from_exposed_addr => (2, 0, vec![param(0)], param(1)),
-        sym::simd_bitmask => (2, 0, vec![param(0)], param(1)),
-        sym::simd_select | sym::simd_select_bitmask => {
-            (2, 0, vec![param(0), param(1), param(1)], param(1))
-        }
-        sym::simd_reduce_all | sym::simd_reduce_any => (1, 0, vec![param(0)], tcx.types.bool),
-        sym::simd_reduce_add_ordered | sym::simd_reduce_mul_ordered => {
-            (2, 0, vec![param(0), param(1)], param(1))
-        }
-        sym::simd_reduce_add_unordered
-        | sym::simd_reduce_mul_unordered
-        | sym::simd_reduce_and
-        | sym::simd_reduce_or
-        | sym::simd_reduce_xor
-        | sym::simd_reduce_min
-        | sym::simd_reduce_max => (2, 0, vec![param(0)], param(1)),
-        sym::simd_shuffle => (3, 0, vec![param(0), param(0), param(1)], param(2)),
-        sym::simd_shuffle_generic => (2, 1, vec![param(0), param(0)], param(1)),
-        _ => {
-            let msg = format!("unrecognized platform-specific intrinsic function: `{name}`");
-            tcx.dcx().span_err(span, msg);
-            return;
-        }
-    };
-
-    let sig = tcx.mk_fn_sig(inputs, output, false, hir::Unsafety::Unsafe, Abi::PlatformIntrinsic);
-    let sig = ty::Binder::dummy(sig);
-    equate_intrinsic_type(tcx, span, intrinsic_id, n_tps, 0, n_cts, sig)
-}

compiler/rustc_hir_analysis/src/check/mod.rs

@@ -142,7 +142,7 @@ fn get_owner_return_paths(
 /// as they must always be defined by the compiler.
 // FIXME: Move this to a more appropriate place.
 pub fn forbid_intrinsic_abi(tcx: TyCtxt<'_>, sp: Span, abi: Abi) {
-    if let Abi::RustIntrinsic | Abi::PlatformIntrinsic = abi {
+    if let Abi::RustIntrinsic = abi {
         tcx.dcx().span_err(sp, "intrinsic must be in `extern \"rust-intrinsic\" { ... }` block");
     }
 }

compiler/rustc_hir_analysis/src/collect.rs

@@ -1677,10 +1677,7 @@ fn compute_sig_of_foreign_fn_decl<'tcx>(
 
     // Feature gate SIMD types in FFI, since I am not sure that the
     // ABIs are handled at all correctly. -huonw
-    if abi != abi::Abi::RustIntrinsic
-        && abi != abi::Abi::PlatformIntrinsic
-        && !tcx.features().simd_ffi
-    {
+    if abi != abi::Abi::RustIntrinsic && !tcx.features().simd_ffi {
         let check = |ast_ty: &hir::Ty<'_>, ty: Ty<'_>| {
             if ty.is_simd() {
                 let snip = tcx

compiler/rustc_hir_typeck/src/coercion.rs

@@ -1177,11 +1177,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         };
         if let (Some(a_sig), Some(b_sig)) = (a_sig, b_sig) {
             // Intrinsics are not coercible to function pointers.
-            if a_sig.abi() == Abi::RustIntrinsic
-                || a_sig.abi() == Abi::PlatformIntrinsic
-                || b_sig.abi() == Abi::RustIntrinsic
-                || b_sig.abi() == Abi::PlatformIntrinsic
-            {
+            if a_sig.abi() == Abi::RustIntrinsic || b_sig.abi() == Abi::RustIntrinsic {
                 return Err(TypeError::IntrinsicCast);
             }
             // The signature must match.

compiler/rustc_lint/src/types.rs

@@ -1587,10 +1587,7 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
     }
 
     fn is_internal_abi(&self, abi: SpecAbi) -> bool {
-        matches!(
-            abi,
-            SpecAbi::Rust | SpecAbi::RustCall | SpecAbi::RustIntrinsic | SpecAbi::PlatformIntrinsic
-        )
+        matches!(abi, SpecAbi::Rust | SpecAbi::RustCall | SpecAbi::RustIntrinsic)
     }
 
     /// Find any fn-ptr types with external ABIs in `ty`.