Auto merge of rust-lang#91728 - Amanieu:stable_asm, r=joshtriplett

Stabilize asm! and global_asm!

Tracking issue: rust-lang#72016

It's been almost 2 years since the original [RFC](rust-lang/rfcs#2850) was posted and we're finally ready to stabilize this feature!

The main changes in this PR are:
- Removing `asm!` and `global_asm!` from the prelude as per the decision in rust-lang#87228.
- Stabilizing the `asm` and `global_asm` features.
- Removing the unstable book pages for `asm` and `global_asm`. The contents are moved to the [reference](rust-lang/reference#1105) and [rust by example](rust-lang/rust-by-example#1483).
  - All links to these pages have been removed to satisfy the link checker. In a later PR these will be replaced with links to the reference or rust by example.
- Removing the automatic suggestion for using `llvm_asm!` instead of `asm!` if you're still using the old syntax, since it doesn't work anymore with `asm!` no longer being in the prelude. This only affects code that predates the old LLVM-style `asm!` being renamed to `llvm_asm!`.
- Updating `stdarch` and `compiler-builtins`.
- Updating all the tests.

r? `@joshtriplett`

Author: bors

core/src/lib.rs

@@ -153,7 +153,6 @@
 #![feature(abi_unadjusted)]
 #![feature(allow_internal_unsafe)]
 #![feature(allow_internal_unstable)]
-#![feature(asm)]
 #![feature(associated_type_bounds)]
 #![feature(auto_traits)]
 #![feature(cfg_target_has_atomic)]
@@ -373,26 +372,14 @@ pub mod arch {
     pub use crate::core_arch::arch::*;
 
     /// Inline assembly.
-    ///
-    /// Read the [unstable book] for the usage.
-    ///
-    /// [unstable book]: ../../unstable-book/library-features/asm.html
-    #[unstable(
-        feature = "asm",
-        issue = "72016",
-        reason = "inline assembly is not stable enough for use and is subject to change"
-    )]
+    #[stable(feature = "asm", since = "1.59.0")]
     #[rustc_builtin_macro]
     pub macro asm("assembly template", $(operands,)* $(options($(option),*))?) {
         /* compiler built-in */
     }
 
     /// Module-level inline assembly.
-    #[unstable(
-        feature = "global_asm",
-        issue = "35119",
-        reason = "`global_asm!` is not stable enough for use and is subject to change"
-    )]
+    #[stable(feature = "global_asm", since = "1.59.0")]
     #[rustc_builtin_macro]
     pub macro global_asm("assembly template", $(operands,)* $(options($(option),*))?) {
         /* compiler built-in */

core/src/num/dec2flt/fpu.rs

@@ -10,6 +10,7 @@ pub use fpu_precision::set_precision;
 // computations are performed in the desired precision.
 #[cfg(all(target_arch = "x86", not(target_feature = "sse2")))]
 mod fpu_precision {
+    use core::arch::asm;
     use core::mem::size_of;
 
     /// A structure used to preserve the original value of the FPU control word, so that it can be

core/src/prelude/v1.rs

@@ -69,22 +69,6 @@ pub use crate::{
 #[doc(no_inline)]
 pub use crate::concat_bytes;
 
-#[unstable(
-    feature = "asm",
-    issue = "72016",
-    reason = "inline assembly is not stable enough for use and is subject to change"
-)]
-#[doc(no_inline)]
-pub use crate::arch::asm;
-
-#[unstable(
-    feature = "global_asm",
-    issue = "35119",
-    reason = "`global_asm!` is not stable enough for use and is subject to change"
-)]
-#[doc(no_inline)]
-pub use crate::arch::global_asm;
-
 #[stable(feature = "builtin_macro_prelude", since = "1.38.0")]
 #[allow(deprecated, deprecated_in_future)]
 #[doc(no_inline)]

panic_abort/src/lib.rs

@@ -14,7 +14,6 @@
 #![feature(std_internals)]
 #![feature(staged_api)]
 #![feature(rustc_attrs)]
-#![feature(asm)]
 #![feature(c_unwind)]
 
 #[cfg(target_os = "android")]
@@ -69,11 +68,11 @@ pub unsafe extern "C-unwind" fn __rust_start_panic(_payload: *mut &mut dyn BoxMe
                 const FAST_FAIL_FATAL_APP_EXIT: usize = 7;
                 cfg_if::cfg_if! {
                     if #[cfg(any(target_arch = "x86", target_arch = "x86_64"))] {
-                        asm!("int $$0x29", in("ecx") FAST_FAIL_FATAL_APP_EXIT);
+                        core::arch::asm!("int $$0x29", in("ecx") FAST_FAIL_FATAL_APP_EXIT);
                     } else if #[cfg(all(target_arch = "arm", target_feature = "thumb-mode"))] {
-                        asm!(".inst 0xDEFB", in("r0") FAST_FAIL_FATAL_APP_EXIT);
+                        core::arch::asm!(".inst 0xDEFB", in("r0") FAST_FAIL_FATAL_APP_EXIT);
                     } else if #[cfg(target_arch = "aarch64")] {
-                        asm!("brk 0xF003", in("x0") FAST_FAIL_FATAL_APP_EXIT);
+                        core::arch::asm!("brk 0xF003", in("x0") FAST_FAIL_FATAL_APP_EXIT);
                     } else {
                         core::intrinsics::abort();
                     }

std/Cargo.toml

@@ -16,7 +16,7 @@ panic_unwind = { path = "../panic_unwind", optional = true }
 panic_abort = { path = "../panic_abort" }
 core = { path = "../core" }
 libc = { version = "0.2.108", default-features = false, features = ['rustc-dep-of-std'] }
-compiler_builtins = { version = "0.1.55" }
+compiler_builtins = { version = "0.1.65" }
 profiler_builtins = { path = "../profiler_builtins", optional = true }
 unwind = { path = "../unwind" }
 hashbrown = { version = "0.11", default-features = false, features = ['rustc-dep-of-std'] }

std/src/lib.rs

@@ -233,7 +233,6 @@
 #![feature(allow_internal_unstable)]
 #![feature(arbitrary_self_types)]
 #![feature(array_error_internals)]
-#![feature(asm)]
 #![feature(assert_matches)]
 #![feature(associated_type_bounds)]
 #![feature(async_stream)]
@@ -287,7 +286,6 @@
 #![feature(gen_future)]
 #![feature(generator_trait)]
 #![feature(get_mut_unchecked)]
-#![feature(global_asm)]
 #![feature(hashmap_internals)]
 #![feature(int_error_internals)]
 #![feature(integer_atomics)]

std/src/os/fortanix_sgx/arch.rs

@@ -5,6 +5,7 @@
 #![unstable(feature = "sgx_platform", issue = "56975")]
 
 use crate::mem::MaybeUninit;
+use core::arch::asm;
 
 /// Wrapper struct to force 16-byte alignment.
 #[repr(align(16))]

std/src/prelude/v1.rs

@@ -54,22 +54,6 @@ pub use core::prelude::v1::{
 #[doc(no_inline)]
 pub use core::prelude::v1::concat_bytes;
 
-#[unstable(
-    feature = "asm",
-    issue = "72016",
-    reason = "inline assembly is not stable enough for use and is subject to change"
-)]
-#[doc(no_inline)]
-pub use core::prelude::v1::asm;
-
-#[unstable(
-    feature = "global_asm",
-    issue = "35119",
-    reason = "`global_asm!` is not stable enough for use and is subject to change"
-)]
-#[doc(no_inline)]
-pub use core::prelude::v1::global_asm;
-
 // FIXME: Attribute and internal derive macros are not documented because for them rustdoc generates
 // dead links which fail link checker testing.
 #[stable(feature = "builtin_macro_prelude", since = "1.38.0")]

std/src/sys/sgx/abi/mem.rs

@@ -1,3 +1,5 @@
+use core::arch::asm;
+
 // Do not remove inline: will result in relocation failure
 #[inline(always)]
 pub(crate) unsafe fn rel_ptr<T>(offset: u64) -> *const T {

std/src/sys/sgx/abi/mod.rs

@@ -1,6 +1,7 @@
 #![cfg_attr(test, allow(unused))] // RT initialization logic is not compiled for test
 
 use crate::io::Write;
+use core::arch::global_asm;
 use core::sync::atomic::{AtomicUsize, Ordering};
 
 // runtime features