From 82ff02b031e70b9ce692f4793f8225da9111286c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lauren=C8=9Biu=20Nicola?= <lnicola@dend.ro>
Date: Mon, 21 Sep 2020 20:25:52 +0300
Subject: [PATCH 1/3] Make char::is_ascii_whitespace branchless on 64-bit

---
 library/core/src/char/methods.rs | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/library/core/src/char/methods.rs b/library/core/src/char/methods.rs
index 2603ecf428c7d..afb4b8995225f 100644
--- a/library/core/src/char/methods.rs
+++ b/library/core/src/char/methods.rs
@@ -1544,9 +1544,18 @@ impl char {
     #[rustc_const_stable(feature = "const_ascii_ctype_on_intrinsics", since = "1.47.0")]
     #[inline]
     pub const fn is_ascii_whitespace(&self) -> bool {
-        match *self {
-            '\t' | '\n' | '\x0C' | '\r' | ' ' => true,
-            _ => false,
+        #[cfg(target_pointer_width = "64")]
+        {
+            // Inspired from https://pdimov.github.io/blog/2020/07/19/llvm-and-memchr/
+            const MASK: u64 = 1 << b'\t' | 1 << b'\n' | 1 << b'\x0C' | 1 << b'\r' | 1 << b' ';
+            *self <= ' ' && 1u64 << (*self as u8) & MASK != 0
+        }
+        #[cfg(not(target_pointer_width = "64"))]
+        {
+            match *self {
+                '\t' | '\n' | '\x0C' | '\r' | ' ' => true,
+                _ => false,
+            }
         }
     }
 

From 960c03920dae153a95bc4ec1b8b2a9caf24d2a8f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lauren=C8=9Biu=20Nicola?= <lnicola@dend.ro>
Date: Mon, 21 Sep 2020 21:18:23 +0300
Subject: [PATCH 2/3] Update mailmap

---
 .mailmap | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/.mailmap b/.mailmap
index fa0728bd79461..69b12834b4bf0 100644
--- a/.mailmap
+++ b/.mailmap
@@ -160,7 +160,8 @@ Kyle J Strand <batmanaod@gmail.com> <BatmanAoD@users.noreply.github.com>
 Kyle J Strand <batmanaod@gmail.com> <kyle.j.strand@gmail.com>
 Kyle J Strand <batmanaod@gmail.com> <kyle.strand@pieinsurance.com>
 Kyle J Strand <batmanaod@gmail.com> <kyle.strand@rms.com>
-Laurențiu Nicola <lnicola@dend.ro>
+Laurențiu Nicola <lnicola@dend.ro> Laurentiu Nicola <lnicola@dend.ro>
+Laurențiu Nicola <lnicola@dend.ro> <lnicola@users.noreply.github.com>
 Lee Jeffery <leejeffery@gmail.com> Lee Jeffery <lee@leejeffery.co.uk>
 Lee Wondong <wdlee91@gmail.com>
 Lennart Kudling <github@kudling.de>

From f1e749519cc967408a4b59b9305ee1cc0eafb2f2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lauren=C8=9Biu=20Nicola?= <lnicola@dend.ro>
Date: Tue, 22 Sep 2020 12:13:51 +0300
Subject: [PATCH 3/3] Use a 32-bit implementation

---
 library/core/src/char/methods.rs | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/library/core/src/char/methods.rs b/library/core/src/char/methods.rs
index afb4b8995225f..e83669cc476b8 100644
--- a/library/core/src/char/methods.rs
+++ b/library/core/src/char/methods.rs
@@ -1544,13 +1544,18 @@ impl char {
     #[rustc_const_stable(feature = "const_ascii_ctype_on_intrinsics", since = "1.47.0")]
     #[inline]
     pub const fn is_ascii_whitespace(&self) -> bool {
-        #[cfg(target_pointer_width = "64")]
+        #[cfg(not(target_pointer_width = "16"))]
         {
             // Inspired from https://pdimov.github.io/blog/2020/07/19/llvm-and-memchr/
-            const MASK: u64 = 1 << b'\t' | 1 << b'\n' | 1 << b'\x0C' | 1 << b'\r' | 1 << b' ';
-            *self <= ' ' && 1u64 << (*self as u8) & MASK != 0
+            const MASK: u32 = 1 << (b'\t' - 1)
+                | 1 << (b'\n' - 1)
+                | 1 << (b'\x0C' - 1)
+                | 1 << (b'\r' - 1)
+                | 1 << (b' ' - 1);
+            let ch = (*self as u32).wrapping_sub(1);
+            ch < (' ' as u32) && 1 << (ch as u8) & MASK != 0
         }
-        #[cfg(not(target_pointer_width = "64"))]
+        #[cfg(target_pointer_width = "16")]
         {
             match *self {
                 '\t' | '\n' | '\x0C' | '\r' | ' ' => true,