git: bf4a70bb405c - stable/13 - libc: Use musl's optimized strchr and strchrnul

From: Ed Maste <emaste_at_FreeBSD.org>
Date: Mon, 13 Dec 2021 00:28:10 UTC
The branch stable/13 has been updated by emaste:

URL: https://cgit.FreeBSD.org/src/commit/?id=bf4a70bb405cbc5e0ecf1babe0e55c220964e46c

commit bf4a70bb405cbc5e0ecf1babe0e55c220964e46c
Author:     Ed Maste <emaste@FreeBSD.org>
AuthorDate: 2021-03-02 01:57:36 +0000
Commit:     Ed Maste <emaste@FreeBSD.org>
CommitDate: 2021-12-12 22:32:33 +0000

    libc: Use musl's optimized strchr and strchrnul
    
    Parentheses added to HASZERO macro to avoid a GCC warning, and formatted
    with clang-format as we have adopted these and don't consider them
    'contrib' code.
    
    Obtained from:  musl (snapshot at commit 4d0a82170a25)
    Reviewed by:    kib (libc integration), mjg (both earlier)
    MFC after:      1 month
    Sponsored by:   The FreeBSD Foundation
    Differential Revision:  https://reviews.freebsd.org/D17630
    
    (cherry picked from commit 7f72497ef756ff7d03d5560c2d1c1f92f73fcb52)
---
 lib/libc/string/strchr.c                | 65 +++++++++++-----------------
 lib/libc/string/strchrnul.c             | 75 +++++++++++++++++++--------------
 libexec/rtld-elf/rtld-libc/Makefile.inc |  4 +-
 stand/libsa/Makefile                    |  2 +-
 4 files changed, 70 insertions(+), 76 deletions(-)

diff --git a/lib/libc/string/strchr.c b/lib/libc/string/strchr.c
index 61244da4519c..4a20ea658252 100644
--- a/lib/libc/string/strchr.c
+++ b/lib/libc/string/strchr.c
@@ -1,56 +1,39 @@
 /*-
- * SPDX-License-Identifier: BSD-3-Clause
+ * SPDX-License-Identifier: MIT
  *
- * Copyright (c) 1990, 1993
- *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 2005-2014 Rich Felker, et al.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- * 3. Neither the name of the University nor the names of its contributors
- *    may be used to endorse or promote products derived from this software
- *    without specific prior written permission.
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
  *
- * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
-
-#if defined(LIBC_SCCS) && !defined(lint)
-static char sccsid[] = "@(#)index.c	8.1 (Berkeley) 6/4/93";
-#endif /* LIBC_SCCS and not lint */
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
-#include <stddef.h>
 #include <string.h>
 
+char *__strchrnul(const char *, int);
+
 char *
-strchr(const char *p, int ch)
+strchr(const char *s, int c)
 {
-	char c;
-
-	c = ch;
-	for (;; ++p) {
-		if (*p == c)
-			return ((char *)p);
-		if (*p == '\0')
-			return (NULL);
-	}
-	/* NOTREACHED */
+	char *r = __strchrnul(s, c);
+	return *(unsigned char *)r == (unsigned char)c ? r : NULL;
 }
 
 __weak_reference(strchr, index);
diff --git a/lib/libc/string/strchrnul.c b/lib/libc/string/strchrnul.c
index 1c777be1854f..e1fb83886042 100644
--- a/lib/libc/string/strchrnul.c
+++ b/lib/libc/string/strchrnul.c
@@ -1,51 +1,62 @@
 /*-
- * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ * SPDX-License-Identifier: MIT
  *
- * Copyright (c) 2013 Niclas Zeising
+ * Copyright (c) 2005-2014 Rich Felker, et al.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
  *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
  *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
-
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
-#include <stddef.h>
+#include <limits.h>
+#include <stdint.h>
 #include <string.h>
 
-__weak_reference(__strchrnul, strchrnul);
+#define ALIGN (sizeof(size_t))
+#define ONES ((size_t)-1 / UCHAR_MAX)
+#define HIGHS (ONES * (UCHAR_MAX / 2 + 1))
+#define HASZERO(x) (((x)-ONES) & ~(x)&HIGHS)
 
 char *__strchrnul(const char *, int);
 
 char *
-__strchrnul(const char *p, int ch)
+__strchrnul(const char *s, int c)
 {
-	char c;
+	c = (unsigned char)c;
+	if (!c)
+		return (char *)s + strlen(s);
 
-	c = ch;
-	for (;; ++p) {
-		if (*p == c || *p == '\0')
-			return ((char *)p);
-	}
-	/* NOTREACHED */
+#ifdef __GNUC__
+	typedef size_t __attribute__((__may_alias__)) word;
+	const word *w;
+	for (; (uintptr_t)s % ALIGN; s++)
+		if (!*s || *(unsigned char *)s == c)
+			return (char *)s;
+	size_t k = ONES * c;
+	for (w = (void *)s; !HASZERO(*w) && !HASZERO(*w ^ k); w++)
+		;
+	s = (void *)w;
+#endif
+	for (; *s && *(unsigned char *)s != c; s++)
+		;
+	return (char *)s;
 }
 
+__weak_reference(__strchrnul, strchrnul);
diff --git a/libexec/rtld-elf/rtld-libc/Makefile.inc b/libexec/rtld-elf/rtld-libc/Makefile.inc
index e3c7ee8ca5cf..ade2dc962aa2 100644
--- a/libexec/rtld-elf/rtld-libc/Makefile.inc
+++ b/libexec/rtld-elf/rtld-libc/Makefile.inc
@@ -41,8 +41,8 @@ CFLAGS.errlst.c+=-I${LIBC_SRCTOP}/include
 # Use the string and memory .o files from libc instead of rebuilding them (they
 # might be using optimized assembly and duplicating that logic here is awkward).
 _libc_string_objects=	bcmp bcopy bzero memset memchr memcmp memcpy memmove \
-    stpncpy strcat strchr strcmp stpcpy strcpy strcspn strdup strlcat strlcpy \
-    strlen strncmp strncpy strrchr strsep strspn strstr strtok
+    stpncpy strcat strchr strchrnul strcmp stpcpy strcpy strcspn strdup \
+    strlcat strlcpy strlen strncmp strncpy strrchr strsep strspn strstr strtok
 # Also use all the syscall .o files from libc_nossp_pic:
 _libc_other_objects= sigsetjmp lstat stat fstat fstatat fstatfs syscall \
     cerror geteuid getegid sigfastblock munmap mprotect \
diff --git a/stand/libsa/Makefile b/stand/libsa/Makefile
index 6fe916405fe4..838fefb260a8 100644
--- a/stand/libsa/Makefile
+++ b/stand/libsa/Makefile
@@ -29,7 +29,7 @@ SRCS+= ntoh.c
 .PATH: ${LIBCSRC}/string
 SRCS+=	bcmp.c bcopy.c bzero.c ffs.c fls.c \
 	memccpy.c memchr.c memcmp.c memcpy.c memmove.c memset.c \
-	strcat.c strchr.c strcmp.c strcpy.c stpcpy.c stpncpy.c \
+	strcat.c strchr.c strchrnul.c strcmp.c strcpy.c stpcpy.c stpncpy.c \
 	strcspn.c strlcat.c strlcpy.c strlen.c strncat.c strncmp.c strncpy.c \
 	strnlen.c strpbrk.c strrchr.c strsep.c strspn.c strstr.c strtok.c swab.c