Rollup merge of #137551 - folkertdev:import-simd-intrinsics, r=RalfJung

import `simd_` intrinsics

In most cases, we can import the simd intrinsics rather than redeclare them. Apparently, most of these tests were written before `std::intrinsics::simd` existed.

There are a couple of exceptions where we can't yet import:

- the intrinsics are not declared as `const fn` in the standard library, causing issues in the `const-eval` tests
- the `simd_shuffle_generic` function is not exposed from `std::intrinsics`
- the `simd_fpow` and `simd_fpowi` functions are not exposed from `std::intrinsics` (removed in #137595)
- some tests use `no_core`, and therefore cannot use `std::intrinsics`

r? ```@RalfJung```

cc ```@workingjubilee``` do you have context on why some intrinsics are not exposed?

Author: jieyouxu

library/core/src/intrinsics/simd.rs

@@ -11,7 +11,7 @@
 /// `idx` must be in-bounds of the vector.
 #[rustc_intrinsic]
 #[rustc_nounwind]
-pub unsafe fn simd_insert<T, U>(_x: T, _idx: u32, _val: U) -> T;
+pub const unsafe fn simd_insert<T, U>(_x: T, _idx: u32, _val: U) -> T;
 
 /// Extracts an element from a vector.
 ///
@@ -22,7 +22,7 @@ pub unsafe fn simd_insert<T, U>(_x: T, _idx: u32, _val: U) -> T;
 /// `idx` must be in-bounds of the vector.
 #[rustc_intrinsic]
 #[rustc_nounwind]
-pub unsafe fn simd_extract<T, U>(_x: T, _idx: u32) -> U;
+pub const unsafe fn simd_extract<T, U>(_x: T, _idx: u32) -> U;
 
 /// Adds two simd vectors elementwise.
 ///

tests/codegen/issues/issue-84268.rs

@@ -1,10 +1,7 @@
 //@ compile-flags: -Copt-level=3 --crate-type=rlib
-#![feature(intrinsics, repr_simd)]
+#![feature(core_intrinsics, repr_simd)]
 
-extern "rust-intrinsic" {
-    fn simd_fabs<T>(x: T) -> T;
-    fn simd_eq<T, U>(x: T, y: T) -> U;
-}
+use std::intrinsics::simd::{simd_eq, simd_fabs};
 
 #[repr(simd)]
 pub struct V([f32; 4]);

tests/codegen/simd-intrinsic/simd-intrinsic-float-abs.rs

@@ -1,10 +1,11 @@
 //@ compile-flags: -C no-prepopulate-passes
 
 #![crate_type = "lib"]
-
-#![feature(repr_simd, intrinsics)]
+#![feature(repr_simd, core_intrinsics)]
 #![allow(non_camel_case_types)]
 
+use std::intrinsics::simd::simd_fabs;
+
 #[repr(simd)]
 #[derive(Copy, Clone, PartialEq, Debug)]
 pub struct f32x2(pub [f32; 2]);
@@ -21,10 +22,6 @@ pub struct f32x8(pub [f32; 8]);
 #[derive(Copy, Clone, PartialEq, Debug)]
 pub struct f32x16(pub [f32; 16]);
 
-extern "rust-intrinsic" {
-    fn simd_fabs<T>(x: T) -> T;
-}
-
 // CHECK-LABEL: @fabs_32x2
 #[no_mangle]
 pub unsafe fn fabs_32x2(a: f32x2) -> f32x2 {

tests/codegen/simd-intrinsic/simd-intrinsic-float-ceil.rs

@@ -1,10 +1,11 @@
 //@ compile-flags: -C no-prepopulate-passes
 
 #![crate_type = "lib"]
-
-#![feature(repr_simd, intrinsics)]
+#![feature(repr_simd, core_intrinsics)]
 #![allow(non_camel_case_types)]
 
+use std::intrinsics::simd::simd_ceil;
+
 #[repr(simd)]
 #[derive(Copy, Clone, PartialEq, Debug)]
 pub struct f32x2(pub [f32; 2]);
@@ -21,10 +22,6 @@ pub struct f32x8(pub [f32; 8]);
 #[derive(Copy, Clone, PartialEq, Debug)]
 pub struct f32x16(pub [f32; 16]);
 
-extern "rust-intrinsic" {
-    fn simd_ceil<T>(x: T) -> T;
-}
-
 // CHECK-LABEL: @ceil_32x2
 #[no_mangle]
 pub unsafe fn ceil_32x2(a: f32x2) -> f32x2 {

tests/codegen/simd-intrinsic/simd-intrinsic-float-cos.rs

@@ -1,10 +1,11 @@
 //@ compile-flags: -C no-prepopulate-passes
 
 #![crate_type = "lib"]
-
-#![feature(repr_simd, intrinsics)]
+#![feature(repr_simd, core_intrinsics)]
 #![allow(non_camel_case_types)]
 
+use std::intrinsics::simd::simd_fcos;
+
 #[repr(simd)]
 #[derive(Copy, Clone, PartialEq, Debug)]
 pub struct f32x2(pub [f32; 2]);
@@ -21,10 +22,6 @@ pub struct f32x8(pub [f32; 8]);
 #[derive(Copy, Clone, PartialEq, Debug)]
 pub struct f32x16(pub [f32; 16]);
 
-extern "rust-intrinsic" {
-    fn simd_fcos<T>(x: T) -> T;
-}
-
 // CHECK-LABEL: @fcos_32x2
 #[no_mangle]
 pub unsafe fn fcos_32x2(a: f32x2) -> f32x2 {

tests/codegen/simd-intrinsic/simd-intrinsic-float-exp.rs

@@ -1,10 +1,11 @@
 //@ compile-flags: -C no-prepopulate-passes
 
 #![crate_type = "lib"]
-
-#![feature(repr_simd, intrinsics)]
+#![feature(repr_simd, core_intrinsics)]
 #![allow(non_camel_case_types)]
 
+use std::intrinsics::simd::simd_fexp;
+
 #[repr(simd)]
 #[derive(Copy, Clone, PartialEq, Debug)]
 pub struct f32x2(pub [f32; 2]);
@@ -21,10 +22,6 @@ pub struct f32x8(pub [f32; 8]);
 #[derive(Copy, Clone, PartialEq, Debug)]
 pub struct f32x16(pub [f32; 16]);
 
-extern "rust-intrinsic" {
-    fn simd_fexp<T>(x: T) -> T;
-}
-
 // CHECK-LABEL: @exp_32x2
 #[no_mangle]
 pub unsafe fn exp_32x2(a: f32x2) -> f32x2 {

tests/codegen/simd-intrinsic/simd-intrinsic-float-exp2.rs

@@ -1,10 +1,11 @@
 //@ compile-flags: -C no-prepopulate-passes
 
 #![crate_type = "lib"]
-
-#![feature(repr_simd, intrinsics)]
+#![feature(repr_simd, core_intrinsics)]
 #![allow(non_camel_case_types)]
 
+use std::intrinsics::simd::simd_fexp2;
+
 #[repr(simd)]
 #[derive(Copy, Clone, PartialEq, Debug)]
 pub struct f32x2(pub [f32; 2]);
@@ -21,10 +22,6 @@ pub struct f32x8(pub [f32; 8]);
 #[derive(Copy, Clone, PartialEq, Debug)]
 pub struct f32x16(pub [f32; 16]);
 
-extern "rust-intrinsic" {
-    fn simd_fexp2<T>(x: T) -> T;
-}
-
 // CHECK-LABEL: @exp2_32x2
 #[no_mangle]
 pub unsafe fn exp2_32x2(a: f32x2) -> f32x2 {

tests/codegen/simd-intrinsic/simd-intrinsic-float-floor.rs

@@ -1,10 +1,11 @@
 //@ compile-flags: -C no-prepopulate-passes
 
 #![crate_type = "lib"]
-
-#![feature(repr_simd, intrinsics)]
+#![feature(repr_simd, core_intrinsics)]
 #![allow(non_camel_case_types)]
 
+use std::intrinsics::simd::simd_floor;
+
 #[repr(simd)]
 #[derive(Copy, Clone, PartialEq, Debug)]
 pub struct f32x2(pub [f32; 2]);
@@ -21,10 +22,6 @@ pub struct f32x8(pub [f32; 8]);
 #[derive(Copy, Clone, PartialEq, Debug)]
 pub struct f32x16(pub [f32; 16]);
 
-extern "rust-intrinsic" {
-    fn simd_floor<T>(x: T) -> T;
-}
-
 // CHECK-LABEL: @floor_32x2
 #[no_mangle]
 pub unsafe fn floor_32x2(a: f32x2) -> f32x2 {

tests/codegen/simd-intrinsic/simd-intrinsic-float-fma.rs

@@ -1,10 +1,11 @@
 //@ compile-flags: -C no-prepopulate-passes
 
 #![crate_type = "lib"]
-
-#![feature(repr_simd, intrinsics)]
+#![feature(repr_simd, core_intrinsics)]
 #![allow(non_camel_case_types)]
 
+use std::intrinsics::simd::simd_fma;
+
 #[repr(simd)]
 #[derive(Copy, Clone, PartialEq, Debug)]
 pub struct f32x2(pub [f32; 2]);
@@ -21,10 +22,6 @@ pub struct f32x8(pub [f32; 8]);
 #[derive(Copy, Clone, PartialEq, Debug)]
 pub struct f32x16(pub [f32; 16]);
 
-extern "rust-intrinsic" {
-    fn simd_fma<T>(x: T, b: T, c: T) -> T;
-}
-
 // CHECK-LABEL: @fma_32x2
 #[no_mangle]
 pub unsafe fn fma_32x2(a: f32x2, b: f32x2, c: f32x2) -> f32x2 {

tests/codegen/simd-intrinsic/simd-intrinsic-float-fsqrt.rs

@@ -1,10 +1,11 @@
 //@ compile-flags: -C no-prepopulate-passes
 
 #![crate_type = "lib"]
-
-#![feature(repr_simd, intrinsics)]
+#![feature(repr_simd, core_intrinsics)]
 #![allow(non_camel_case_types)]
 
+use std::intrinsics::simd::simd_fsqrt;
+
 #[repr(simd)]
 #[derive(Copy, Clone, PartialEq, Debug)]
 pub struct f32x2(pub [f32; 2]);
@@ -21,10 +22,6 @@ pub struct f32x8(pub [f32; 8]);
 #[derive(Copy, Clone, PartialEq, Debug)]
 pub struct f32x16(pub [f32; 16]);
 
-extern "rust-intrinsic" {
-    fn simd_fsqrt<T>(x: T) -> T;
-}
-
 // CHECK-LABEL: @fsqrt_32x2
 #[no_mangle]
 pub unsafe fn fsqrt_32x2(a: f32x2) -> f32x2 {