rust-lang · rust-bors · Jan 26, 2026 · Jan 5, 2026 · Jan 22, 2026 · Jan 22, 2026
diff --git a/Cargo.lock b/Cargo.lock
@@ -857,7 +857,7 @@ dependencies = [
  "tracing-subscriber",
  "unified-diff",
  "walkdir",
- "windows",
+ "windows 0.61.3",
 ]
 
 [[package]]
@@ -2038,7 +2038,7 @@ dependencies = [
  "serde",
  "tempfile",
  "uuid",
- "windows",
+ "windows 0.61.3",
 ]
 
 [[package]]
@@ -3698,7 +3698,7 @@ dependencies = [
  "thorin-dwp",
  "tracing",
  "wasm-encoder 0.219.2",
- "windows",
+ "windows 0.61.3",
 ]
 
 [[package]]
@@ -3756,7 +3756,7 @@ dependencies = [
  "tempfile",
  "thin-vec",
  "tracing",
- "windows",
+ "windows 0.61.3",
 ]
 
 [[package]]
@@ -3822,7 +3822,7 @@ dependencies = [
  "serde_json",
  "shlex",
  "tracing",
- "windows",
+ "windows 0.61.3",
 ]
 
 [[package]]
@@ -3873,7 +3873,7 @@ dependencies = [
  "serde_json",
  "termize",
  "tracing",
- "windows",
+ "windows 0.61.3",
 ]
 
 [[package]]
@@ -4664,7 +4664,7 @@ dependencies = [
  "rustc_target",
  "termize",
  "tracing",
- "windows",
+ "windows 0.61.3",
 ]
 
 [[package]]
@@ -5438,14 +5438,14 @@ dependencies = [
 
 [[package]]
 name = "sysinfo"
-version = "0.37.2"
+version = "0.38.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "16607d5caffd1c07ce073528f9ed972d88db15dd44023fa57142963be3feb11f"
+checksum = "fe840c5b1afe259a5657392a4dbb74473a14c8db999c3ec2f4ae812e028a94da"
 dependencies = [
  "libc",
  "objc2-core-foundation",
  "objc2-io-kit",
- "windows",
+ "windows 0.62.2",
 ]
 
 [[package]]
@@ -6398,11 +6398,23 @@ version = "0.61.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9babd3a767a4c1aef6900409f85f5d53ce2544ccdfaa86dad48c91782c6d6893"
 dependencies = [
- "windows-collections",
+ "windows-collections 0.2.0",
  "windows-core 0.61.2",
- "windows-future",
+ "windows-future 0.2.1",
  "windows-link 0.1.3",
- "windows-numerics",
+ "windows-numerics 0.2.0",
+]
+
+[[package]]
+name = "windows"
+version = "0.62.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "527fadee13e0c05939a6a05d5bd6eec6cd2e3dbd648b9f8e447c6518133d8580"
+dependencies = [
+ "windows-collections 0.3.2",
+ "windows-core 0.62.2",
+ "windows-future 0.3.2",
+ "windows-numerics 0.3.1",
 ]
 
 [[package]]
@@ -6413,7 +6425,7 @@ checksum = "9b4e97b01190d32f268a2dfbd3f006f77840633746707fbe40bcee588108a231"
 dependencies = [
  "serde",
  "serde_json",
- "windows-threading",
+ "windows-threading 0.1.0",
 ]
 
 [[package]]
@@ -6425,6 +6437,15 @@ dependencies = [
  "windows-core 0.61.2",
 ]
 
+[[package]]
+name = "windows-collections"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "23b2d95af1a8a14a3c7367e1ed4fc9c20e0a26e79551b1454d72583c97cc6610"
+dependencies = [
+ "windows-core 0.62.2",
+]
+
 [[package]]
 name = "windows-core"
 version = "0.61.2"
@@ -6459,7 +6480,18 @@ checksum = "fc6a41e98427b19fe4b73c550f060b59fa592d7d686537eebf9385621bfbad8e"
 dependencies = [
  "windows-core 0.61.2",
  "windows-link 0.1.3",
- "windows-threading",
+ "windows-threading 0.1.0",
+]
+
+[[package]]
+name = "windows-future"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e1d6f90251fe18a279739e78025bd6ddc52a7e22f921070ccdc67dde84c605cb"
+dependencies = [
+ "windows-core 0.62.2",
+ "windows-link 0.2.1",
+ "windows-threading 0.2.1",
 ]
 
 [[package]]
@@ -6506,6 +6538,16 @@ dependencies = [
  "windows-link 0.1.3",
 ]
 
+[[package]]
+name = "windows-numerics"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6e2e40844ac143cdb44aead537bbf727de9b044e107a0f1220392177d15b0f26"
+dependencies = [
+ "windows-core 0.62.2",
+ "windows-link 0.2.1",
+]
+
 [[package]]
 name = "windows-result"
 version = "0.3.4"
@@ -6611,6 +6653,15 @@ dependencies = [
  "windows-link 0.1.3",
 ]
 
+[[package]]
+name = "windows-threading"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3949bd5b99cafdf1c7ca86b43ca564028dfe27d66958f2470940f73d86d75b37"
+dependencies = [
+ "windows-link 0.2.1",
+]
+
 [[package]]
 name = "windows_aarch64_gnullvm"
 version = "0.52.6"

diff --git a/compiler/rustc_session/src/config.rs b/compiler/rustc_session/src/config.rs
@@ -1322,18 +1322,26 @@ impl OutputFilenames {
 pub(crate) fn parse_remap_path_scope(
     early_dcx: &EarlyDiagCtxt,
     matches: &getopts::Matches,
+    unstable_opts: &UnstableOptions,
 ) -> RemapPathScopeComponents {
     if let Some(v) = matches.opt_str("remap-path-scope") {
         let mut slot = RemapPathScopeComponents::empty();
         for s in v.split(',') {
             slot |= match s {
                 "macro" => RemapPathScopeComponents::MACRO,
                 "diagnostics" => RemapPathScopeComponents::DIAGNOSTICS,
+                "documentation" => {
+                    if !unstable_opts.unstable_options {
+                        early_dcx.early_fatal("remapping `documentation` path scope requested but `-Zunstable-options` not specified");
+                    }
+
+                    RemapPathScopeComponents::DOCUMENTATION
+                },
                 "debuginfo" => RemapPathScopeComponents::DEBUGINFO,
                 "coverage" => RemapPathScopeComponents::COVERAGE,
                 "object" => RemapPathScopeComponents::OBJECT,
                 "all" => RemapPathScopeComponents::all(),
-                _ => early_dcx.early_fatal("argument for `--remap-path-scope` must be a comma separated list of scopes: `macro`, `diagnostics`, `debuginfo`, `coverage`, `object`, `all`"),
+                _ => early_dcx.early_fatal("argument for `--remap-path-scope` must be a comma separated list of scopes: `macro`, `diagnostics`, `documentation`, `debuginfo`, `coverage`, `object`, `all`"),
             }
         }
         slot
@@ -2677,7 +2685,7 @@ pub fn build_session_options(early_dcx: &mut EarlyDiagCtxt, matches: &getopts::M
     let externs = parse_externs(early_dcx, matches, &unstable_opts);
 
     let remap_path_prefix = parse_remap_path_prefix(early_dcx, matches, &unstable_opts);
-    let remap_path_scope = parse_remap_path_scope(early_dcx, matches);
+    let remap_path_scope = parse_remap_path_scope(early_dcx, matches, &unstable_opts);
 
     let pretty = parse_pretty(early_dcx, &unstable_opts);
 

diff --git a/compiler/rustc_span/src/lib.rs b/compiler/rustc_span/src/lib.rs
@@ -233,6 +233,8 @@ bitflags::bitflags! {
         const DEBUGINFO = 1 << 3;
         /// Apply remappings to coverage information
         const COVERAGE = 1 << 4;
+        /// Apply remappings to documentation information
+        const DOCUMENTATION = 1 << 5;
 
         /// An alias for `macro`, `debuginfo` and `coverage`. This ensures all paths in compiled
         /// executables, libraries and objects are remapped but not elsewhere.

diff --git a/library/core/src/pin.rs b/library/core/src/pin.rs
@@ -831,15 +831,13 @@
 //!     <code>fn get_pin_mut(self: [Pin]<[`&mut Self`]>) -> [Pin]<[`&mut T`]></code>.
 //!     Then we could do the following:
 //!     ```compile_fail
-//!     # use std::cell::RefCell;
-//!     # use std::pin::Pin;
-//!     fn exploit_ref_cell<T>(rc: Pin<&mut RefCell<T>>) {
+//!     fn exploit_ref_cell<T>(mut rc: Pin<&mut RefCell<T>>) {
 //!         // Here we get pinned access to the `T`.
 //!         let _: Pin<&mut T> = rc.as_mut().get_pin_mut();
 //!
 //!         // And here we have `&mut T` to the same data.
 //!         let shared: &RefCell<T> = rc.into_ref().get_ref();
-//!         let borrow = shared.borrow_mut();
+//!         let mut borrow = shared.borrow_mut();
 //!         let content = &mut *borrow;
 //!     }
 //!     ```

diff --git a/library/core/src/slice/ascii.rs b/library/core/src/slice/ascii.rs
@@ -460,56 +460,38 @@ const fn is_ascii(s: &[u8]) -> bool {
     )
 }
 
-/// Chunk size for vectorized ASCII checking (two 16-byte SSE registers).
+/// Chunk size for SSE2 vectorized ASCII checking (4x 16-byte loads).
 #[cfg(all(target_arch = "x86_64", target_feature = "sse2"))]
-const CHUNK_SIZE: usize = 32;
+const SSE2_CHUNK_SIZE: usize = 64;
 
-/// SSE2 implementation using `_mm_movemask_epi8` (compiles to `pmovmskb`) to
-/// avoid LLVM's broken AVX-512 auto-vectorization of counting loops.
-///
-/// FIXME(llvm#176906): Remove this workaround once LLVM generates efficient code.
 #[cfg(all(target_arch = "x86_64", target_feature = "sse2"))]
+#[inline]
 fn is_ascii_sse2(bytes: &[u8]) -> bool {
     use crate::arch::x86_64::{__m128i, _mm_loadu_si128, _mm_movemask_epi8, _mm_or_si128};
 
-    let mut i = 0;
-
-    while i + CHUNK_SIZE <= bytes.len() {
-        // SAFETY: We have verified that `i + CHUNK_SIZE <= bytes.len()`.
-        let ptr = unsafe { bytes.as_ptr().add(i) };
-
-        // Load two 16-byte chunks and combine them.
-        // SAFETY: We verified `i + 32 <= len`, so ptr is valid for 32 bytes.
-        // `_mm_loadu_si128` allows unaligned loads.
-        let chunk1 = unsafe { _mm_loadu_si128(ptr as *const __m128i) };
-        // SAFETY: Same as above - ptr.add(16) is within the valid 32-byte range.
-        let chunk2 = unsafe { _mm_loadu_si128(ptr.add(16) as *const __m128i) };
-
-        // OR them together - if any byte has the high bit set, the result will too.
-        // SAFETY: SSE2 is guaranteed by the cfg predicate.
-        let combined = unsafe { _mm_or_si128(chunk1, chunk2) };
-
-        // Create a mask from the MSBs of each byte.
-        // If any byte is >= 128, its MSB is 1, so the mask will be non-zero.
-        // SAFETY: SSE2 is guaranteed by the cfg predicate.
-        let mask = unsafe { _mm_movemask_epi8(combined) };
-
+    let (chunks, rest) = bytes.as_chunks::<SSE2_CHUNK_SIZE>();
+
+    for chunk in chunks {
+        let ptr = chunk.as_ptr();
+        // SAFETY: chunk is 64 bytes. SSE2 is baseline on x86_64.
+        let mask = unsafe {
+            let a1 = _mm_loadu_si128(ptr as *const __m128i);
+            let a2 = _mm_loadu_si128(ptr.add(16) as *const __m128i);
+            let b1 = _mm_loadu_si128(ptr.add(32) as *const __m128i);
+            let b2 = _mm_loadu_si128(ptr.add(48) as *const __m128i);
+            // OR all chunks - if any byte has high bit set, combined will too.
+            let combined = _mm_or_si128(_mm_or_si128(a1, a2), _mm_or_si128(b1, b2));
+            // Create a mask from the MSBs of each byte.
+            // If any byte is >= 128, its MSB is 1, so the mask will be non-zero.
+            _mm_movemask_epi8(combined)
+        };
         if mask != 0 {
             return false;
         }
-
-        i += CHUNK_SIZE;
-    }
-
-    // Handle remaining bytes with simple loop
-    while i < bytes.len() {
-        if !bytes[i].is_ascii() {
-            return false;
-        }
-        i += 1;
     }
 
-    true
+    // Handle remaining bytes
+    rest.iter().all(|b| b.is_ascii())
 }
 
 /// ASCII test optimized to use the `pmovmskb` instruction on `x86-64`.
@@ -529,7 +511,7 @@ const fn is_ascii(bytes: &[u8]) -> bool {
             is_ascii_simple(bytes)
         } else {
             // For small inputs, use usize-at-a-time processing to avoid SSE2 call overhead.
-            if bytes.len() < CHUNK_SIZE {
+            if bytes.len() < SSE2_CHUNK_SIZE {
                 let chunks = bytes.chunks_exact(USIZE_SIZE);
                 let remainder = chunks.remainder();
                 for chunk in chunks {