Rollup of 10 pull requests

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -1333,9 +1333,6 @@ fn add_late_link_args(
     crate_type: CrateType,
     codegen_results: &CodegenResults,
 ) {
-    if let Some(args) = sess.target.target.options.late_link_args.get(&flavor) {
-        cmd.args(args);
-    }
     let any_dynamic_crate = crate_type == CrateType::Dylib
         || codegen_results.crate_info.dependency_formats.iter().any(|(ty, list)| {
             *ty == crate_type && list.iter().any(|&linkage| linkage == Linkage::Dynamic)
@@ -1349,6 +1346,9 @@ fn add_late_link_args(
             cmd.args(args);
         }
     }
+    if let Some(args) = sess.target.target.options.late_link_args.get(&flavor) {
+        cmd.args(args);
+    }
 }
 
 /// Add arbitrary "post-link" args defined by the target spec.

compiler/rustc_middle/src/ty/mod.rs

@@ -682,25 +682,31 @@ pub enum BorrowKind {
     /// implicit closure bindings. It is needed when the closure
     /// is borrowing or mutating a mutable referent, e.g.:
     ///
-    ///    let x: &mut isize = ...;
-    ///    let y = || *x += 5;
+    /// ```
+    /// let x: &mut isize = ...;
+    /// let y = || *x += 5;
+    /// ```
     ///
     /// If we were to try to translate this closure into a more explicit
     /// form, we'd encounter an error with the code as written:
     ///
-    ///    struct Env { x: & &mut isize }
-    ///    let x: &mut isize = ...;
-    ///    let y = (&mut Env { &x }, fn_ptr);  // Closure is pair of env and fn
-    ///    fn fn_ptr(env: &mut Env) { **env.x += 5; }
+    /// ```
+    /// struct Env { x: & &mut isize }
+    /// let x: &mut isize = ...;
+    /// let y = (&mut Env { &x }, fn_ptr);  // Closure is pair of env and fn
+    /// fn fn_ptr(env: &mut Env) { **env.x += 5; }
+    /// ```
     ///
     /// This is then illegal because you cannot mutate a `&mut` found
     /// in an aliasable location. To solve, you'd have to translate with
     /// an `&mut` borrow:
     ///
-    ///    struct Env { x: & &mut isize }
-    ///    let x: &mut isize = ...;
-    ///    let y = (&mut Env { &mut x }, fn_ptr); // changed from &x to &mut x
-    ///    fn fn_ptr(env: &mut Env) { **env.x += 5; }
+    /// ```
+    /// struct Env { x: & &mut isize }
+    /// let x: &mut isize = ...;
+    /// let y = (&mut Env { &mut x }, fn_ptr); // changed from &x to &mut x
+    /// fn fn_ptr(env: &mut Env) { **env.x += 5; }
+    /// ```
     ///
     /// Now the assignment to `**env.x` is legal, but creating a
     /// mutable pointer to `x` is not because `x` is not mutable. We

compiler/rustc_mir/src/transform/const_prop.rs

@@ -1046,9 +1046,9 @@ impl<'mir, 'tcx> MutVisitor<'tcx> for ConstPropagator<'mir, 'tcx> {
     fn visit_operand(&mut self, operand: &mut Operand<'tcx>, location: Location) {
         self.super_operand(operand, location);
 
-        // Only const prop copies and moves on `mir_opt_level=3` as doing so
-        // currently increases compile time.
-        if self.tcx.sess.opts.debugging_opts.mir_opt_level >= 3 {
+        // Only const prop copies and moves on `mir_opt_level=2` as doing so
+        // currently slightly increases compile time in some cases.
+        if self.tcx.sess.opts.debugging_opts.mir_opt_level >= 2 {
             self.propagate_operand(operand)
         }
     }
@@ -1246,8 +1246,8 @@ impl<'mir, 'tcx> MutVisitor<'tcx> for ConstPropagator<'mir, 'tcx> {
             | TerminatorKind::InlineAsm { .. } => {}
             // Every argument in our function calls have already been propagated in `visit_operand`.
             //
-            // NOTE: because LLVM codegen gives performance regressions with it, so this is gated
-            // on `mir_opt_level=3`.
+            // NOTE: because LLVM codegen gives slight performance regressions with it, so this is
+            // gated on `mir_opt_level=2`.
             TerminatorKind::Call { .. } => {}
         }
 

compiler/rustc_mir/src/transform/mod.rs

@@ -36,7 +36,6 @@ pub mod match_branches;
 pub mod no_landing_pads;
 pub mod nrvo;
 pub mod promote_consts;
-pub mod qualify_min_const_fn;
 pub mod remove_noop_landing_pads;
 pub mod remove_unneeded_drops;
 pub mod required_consts;

compiler/rustc_parse/src/lib.rs

@@ -7,7 +7,7 @@
 #![feature(or_patterns)]
 
 use rustc_ast as ast;
-use rustc_ast::token::{self, DelimToken, Nonterminal, Token, TokenKind};
+use rustc_ast::token::{self, Nonterminal, Token, TokenKind};
 use rustc_ast::tokenstream::{self, Spacing, TokenStream, TokenTree};
 use rustc_ast_pretty::pprust;
 use rustc_data_structures::sync::Lrc;
@@ -299,7 +299,7 @@ pub fn nt_to_tokenstream(nt: &Nonterminal, sess: &ParseSess, span: Span) -> Toke
     // FIXME(#43081): Avoid this pretty-print + reparse hack
     let source = pprust::nonterminal_to_string(nt);
     let filename = FileName::macro_expansion_source_code(&source);
-    let tokens_for_real = parse_stream_from_source_str(filename, source, sess, Some(span));
+    let reparsed_tokens = parse_stream_from_source_str(filename, source, sess, Some(span));
 
     // During early phases of the compiler the AST could get modified
     // directly (e.g., attributes added or removed) and the internal cache
@@ -325,17 +325,17 @@ pub fn nt_to_tokenstream(nt: &Nonterminal, sess: &ParseSess, span: Span) -> Toke
     // modifications, including adding/removing typically non-semantic
     // tokens such as extra braces and commas, don't happen.
     if let Some(tokens) = tokens {
-        if tokenstream_probably_equal_for_proc_macro(&tokens, &tokens_for_real, sess) {
+        if tokenstream_probably_equal_for_proc_macro(&tokens, &reparsed_tokens, sess) {
             return tokens;
         }
         info!(
             "cached tokens found, but they're not \"probably equal\", \
                 going with stringified version"
         );
         info!("cached tokens: {:?}", tokens);
-        info!("reparsed tokens: {:?}", tokens_for_real);
+        info!("reparsed tokens: {:?}", reparsed_tokens);
     }
-    tokens_for_real
+    reparsed_tokens
 }
 
 // See comments in `Nonterminal::to_tokenstream` for why we care about
@@ -344,8 +344,8 @@ pub fn nt_to_tokenstream(nt: &Nonterminal, sess: &ParseSess, span: Span) -> Toke
 // This is otherwise the same as `eq_unspanned`, only recursing with a
 // different method.
 pub fn tokenstream_probably_equal_for_proc_macro(
-    first: &TokenStream,
-    other: &TokenStream,
+    tokens: &TokenStream,
+    reparsed_tokens: &TokenStream,
     sess: &ParseSess,
 ) -> bool {
     // When checking for `probably_eq`, we ignore certain tokens that aren't
@@ -359,9 +359,6 @@ pub fn tokenstream_probably_equal_for_proc_macro(
                 // The pretty printer tends to add trailing commas to
                 // everything, and in particular, after struct fields.
                 | token::Comma
-                // The pretty printer emits `NoDelim` as whitespace.
-                | token::OpenDelim(DelimToken::NoDelim)
-                | token::CloseDelim(DelimToken::NoDelim)
                 // The pretty printer collapses many semicolons into one.
                 | token::Semi
                 // We don't preserve leading `|` tokens in patterns, so
@@ -460,10 +457,11 @@ pub fn tokenstream_probably_equal_for_proc_macro(
 
     // Break tokens after we expand any nonterminals, so that we break tokens
     // that are produced as a result of nonterminal expansion.
-    let t1 = first.trees().filter(semantic_tree).flat_map(expand_nt).flat_map(break_tokens);
-    let t2 = other.trees().filter(semantic_tree).flat_map(expand_nt).flat_map(break_tokens);
+    let tokens = tokens.trees().filter(semantic_tree).flat_map(expand_nt).flat_map(break_tokens);
+    let reparsed_tokens =
+        reparsed_tokens.trees().filter(semantic_tree).flat_map(expand_nt).flat_map(break_tokens);
 
-    t1.eq_by(t2, |t1, t2| tokentree_probably_equal_for_proc_macro(&t1, &t2, sess))
+    tokens.eq_by(reparsed_tokens, |t, rt| tokentree_probably_equal_for_proc_macro(&t, &rt, sess))
 }
 
 // See comments in `Nonterminal::to_tokenstream` for why we care about
@@ -472,16 +470,20 @@ pub fn tokenstream_probably_equal_for_proc_macro(
 // This is otherwise the same as `eq_unspanned`, only recursing with a
 // different method.
 pub fn tokentree_probably_equal_for_proc_macro(
-    first: &TokenTree,
-    other: &TokenTree,
+    token: &TokenTree,
+    reparsed_token: &TokenTree,
     sess: &ParseSess,
 ) -> bool {
-    match (first, other) {
-        (TokenTree::Token(token), TokenTree::Token(token2)) => {
-            token_probably_equal_for_proc_macro(token, token2)
+    match (token, reparsed_token) {
+        (TokenTree::Token(token), TokenTree::Token(reparsed_token)) => {
+            token_probably_equal_for_proc_macro(token, reparsed_token)
         }
-        (TokenTree::Delimited(_, delim, tts), TokenTree::Delimited(_, delim2, tts2)) => {
-            delim == delim2 && tokenstream_probably_equal_for_proc_macro(&tts, &tts2, sess)
+        (
+            TokenTree::Delimited(_, delim, tokens),
+            TokenTree::Delimited(_, reparsed_delim, reparsed_tokens),
+        ) => {
+            delim == reparsed_delim
+                && tokenstream_probably_equal_for_proc_macro(tokens, reparsed_tokens, sess)
         }
         _ => false,
     }

compiler/rustc_target/src/spec/windows_gnu_base.rs

@@ -23,6 +23,7 @@ pub fn opts() -> TargetOptions {
         "-lmsvcrt".to_string(),
         "-lmingwex".to_string(),
         "-lmingw32".to_string(),
+        "-lgcc".to_string(), // alas, mingw* libraries above depend on libgcc
         // mingw's msvcrt is a weird hybrid import library and static library.
         // And it seems that the linker fails to use import symbols from msvcrt
         // that are required from functions in msvcrt in certain cases. For example
@@ -41,8 +42,6 @@ pub fn opts() -> TargetOptions {
         // the shared libgcc_s-dw2-1.dll. This is required to support
         // unwinding across DLL boundaries.
         "-lgcc_s".to_string(),
-        "-lgcc".to_string(),
-        "-lkernel32".to_string(),
     ];
     late_link_args_dynamic.insert(LinkerFlavor::Gcc, dynamic_unwind_libs.clone());
     late_link_args_dynamic.insert(LinkerFlavor::Lld(LldFlavor::Ld), dynamic_unwind_libs);
@@ -54,10 +53,6 @@ pub fn opts() -> TargetOptions {
         // boundaries when unwinding across FFI boundaries.
         "-lgcc_eh".to_string(),
         "-l:libpthread.a".to_string(),
-        "-lgcc".to_string(),
-        // libpthread depends on libmsvcrt, so we need to link it *again*.
-        "-lmsvcrt".to_string(),
-        "-lkernel32".to_string(),
     ];
     late_link_args_static.insert(LinkerFlavor::Gcc, static_unwind_libs.clone());
     late_link_args_static.insert(LinkerFlavor::Lld(LldFlavor::Ld), static_unwind_libs);

library/alloc/benches/vec.rs

@@ -1,4 +1,4 @@
-use rand::prelude::*;
+use rand::RngCore;
 use std::iter::{repeat, FromIterator};
 use test::{black_box, Bencher};
 

library/core/src/slice/cmp.rs

@@ -268,12 +268,14 @@ where
 }
 
 impl SliceContains for u8 {
+    #[inline]
     fn slice_contains(&self, x: &[Self]) -> bool {
         memchr::memchr(*self, x).is_some()
     }
 }
 
 impl SliceContains for i8 {
+    #[inline]
     fn slice_contains(&self, x: &[Self]) -> bool {
         let byte = *self as u8;
         // SAFETY: `i8` and `u8` have the same memory layout, thus casting `x.as_ptr()`

library/core/src/slice/memchr.rs

@@ -12,6 +12,7 @@ const HI_U64: u64 = 0x8080808080808080;
 // Use truncation.
 const LO_USIZE: usize = LO_U64 as usize;
 const HI_USIZE: usize = HI_U64 as usize;
+const USIZE_BYTES: usize = mem::size_of::<usize>();
 
 /// Returns `true` if `x` contains any zero byte.
 ///
@@ -38,19 +39,30 @@ fn repeat_byte(b: u8) -> usize {
 }
 
 /// Returns the first index matching the byte `x` in `text`.
+#[inline]
 pub fn memchr(x: u8, text: &[u8]) -> Option<usize> {
+    // Fast path for small slices
+    if text.len() < 2 * USIZE_BYTES {
+        return text.iter().position(|elt| *elt == x);
+    }
+
+    memchr_general_case(x, text)
+}
+
+#[inline(never)]
+fn memchr_general_case(x: u8, text: &[u8]) -> Option<usize> {
     // Scan for a single byte value by reading two `usize` words at a time.
     //
     // Split `text` in three parts
     // - unaligned initial part, before the first word aligned address in text
     // - body, scan by 2 words at a time
     // - the last remaining part, < 2 word size
+
+    // search up to an aligned boundary
     let len = text.len();
     let ptr = text.as_ptr();
-    let usize_bytes = mem::size_of::<usize>();
+    let mut offset = ptr.align_offset(USIZE_BYTES);
 
-    // search up to an aligned boundary
-    let mut offset = ptr.align_offset(usize_bytes);
     if offset > 0 {
         offset = cmp::min(offset, len);
         if let Some(index) = text[..offset].iter().position(|elt| *elt == x) {
@@ -60,22 +72,19 @@ pub fn memchr(x: u8, text: &[u8]) -> Option<usize> {
 
     // search the body of the text
     let repeated_x = repeat_byte(x);
+    while offset <= len - 2 * USIZE_BYTES {
+        unsafe {
+            let u = *(ptr.add(offset) as *const usize);
+            let v = *(ptr.add(offset + USIZE_BYTES) as *const usize);
 
-    if len >= 2 * usize_bytes {
-        while offset <= len - 2 * usize_bytes {
-            unsafe {
-                let u = *(ptr.add(offset) as *const usize);
-                let v = *(ptr.add(offset + usize_bytes) as *const usize);
-
-                // break if there is a matching byte
-                let zu = contains_zero_byte(u ^ repeated_x);
-                let zv = contains_zero_byte(v ^ repeated_x);
-                if zu || zv {
-                    break;
-                }
+            // break if there is a matching byte
+            let zu = contains_zero_byte(u ^ repeated_x);
+            let zv = contains_zero_byte(v ^ repeated_x);
+            if zu || zv {
+                break;
             }
-            offset += usize_bytes * 2;
         }
+        offset += USIZE_BYTES * 2;
     }
 
     // Find the byte after the point the body loop stopped.

library/core/src/slice/mod.rs

@@ -1636,6 +1636,7 @@ impl<T> [T] {
     /// assert!(!v.iter().any(|e| e == "hi"));
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[inline]
     pub fn contains(&self, x: &T) -> bool
     where
         T: PartialEq,

library/core/tests/num/mod.rs

@@ -634,14 +634,18 @@ assume_usize_width! {
 macro_rules! test_float {
     ($modname: ident, $fty: ty, $inf: expr, $neginf: expr, $nan: expr) => {
         mod $modname {
-            // FIXME(nagisa): these tests should test for sign of -0.0
             #[test]
             fn min() {
                 assert_eq!((0.0 as $fty).min(0.0), 0.0);
+                assert!((0.0 as $fty).min(0.0).is_sign_positive());
                 assert_eq!((-0.0 as $fty).min(-0.0), -0.0);
+                assert!((-0.0 as $fty).min(-0.0).is_sign_negative());
                 assert_eq!((9.0 as $fty).min(9.0), 9.0);
                 assert_eq!((-9.0 as $fty).min(0.0), -9.0);
                 assert_eq!((0.0 as $fty).min(9.0), 0.0);
+                assert!((0.0 as $fty).min(9.0).is_sign_positive());
+                assert_eq!((-0.0 as $fty).min(9.0), -0.0);
+                assert!((-0.0 as $fty).min(9.0).is_sign_negative());
                 assert_eq!((-0.0 as $fty).min(-9.0), -9.0);
                 assert_eq!(($inf as $fty).min(9.0), 9.0);
                 assert_eq!((9.0 as $fty).min($inf), 9.0);
@@ -660,11 +664,19 @@ macro_rules! test_float {
             #[test]
             fn max() {
                 assert_eq!((0.0 as $fty).max(0.0), 0.0);
+                assert!((0.0 as $fty).max(0.0).is_sign_positive());
                 assert_eq!((-0.0 as $fty).max(-0.0), -0.0);
+                assert!((-0.0 as $fty).max(-0.0).is_sign_negative());
                 assert_eq!((9.0 as $fty).max(9.0), 9.0);
                 assert_eq!((-9.0 as $fty).max(0.0), 0.0);
+                assert!((-9.0 as $fty).max(0.0).is_sign_positive());
+                assert_eq!((-9.0 as $fty).max(-0.0), -0.0);
+                assert!((-9.0 as $fty).max(-0.0).is_sign_negative());
                 assert_eq!((0.0 as $fty).max(9.0), 9.0);
+                assert_eq!((0.0 as $fty).max(-9.0), 0.0);
+                assert!((0.0 as $fty).max(-9.0).is_sign_positive());
                 assert_eq!((-0.0 as $fty).max(-9.0), -0.0);
+                assert!((-0.0 as $fty).max(-9.0).is_sign_negative());
                 assert_eq!(($inf as $fty).max(9.0), $inf);
                 assert_eq!((9.0 as $fty).max($inf), $inf);
                 assert_eq!(($inf as $fty).max(-9.0), $inf);