From: James Tirta Halim <tirtajames45@gmail.com>
To: newlib@sourceware.org
Cc: James Tirta Halim <tirtajames45@gmail.com>
Subject: [PATCH] strchr, strchrnul: implement strchr() as strchrnul()
Date: Tue, 5 Dec 2023 21:58:39 +0700 [thread overview]
Message-ID: <20231205145839.474295-1-tirtajames45@gmail.com> (raw)
---
newlib/libc/string/strchr.c | 81 +---------------------------------
newlib/libc/string/strchrnul.c | 77 +++++++++++++++++++++++++++++++-
2 files changed, 77 insertions(+), 81 deletions(-)
diff --git a/newlib/libc/string/strchr.c b/newlib/libc/string/strchr.c
index 96f30be04..382275b1d 100644
--- a/newlib/libc/string/strchr.c
+++ b/newlib/libc/string/strchr.c
@@ -30,87 +30,10 @@ QUICKREF
#include <string.h>
#include <limits.h>
-/* Nonzero if X is not aligned on a "long" boundary. */
-#define UNALIGNED(X) ((long)X & (sizeof (long) - 1))
-
-/* How many bytes are loaded each iteration of the word copy loop. */
-#define LBLOCKSIZE (sizeof (long))
-
-#if LONG_MAX == 2147483647L
-#define DETECTNULL(X) (((X) - 0x01010101) & ~(X) & 0x80808080)
-#else
-#if LONG_MAX == 9223372036854775807L
-/* Nonzero if X (a long int) contains a NULL byte. */
-#define DETECTNULL(X) (((X) - 0x0101010101010101) & ~(X) & 0x8080808080808080)
-#else
-#error long int is not a 32bit or 64bit type.
-#endif
-#endif
-
-/* DETECTCHAR returns nonzero if (long)X contains the byte used
- to fill (long)MASK. */
-#define DETECTCHAR(X,MASK) (DETECTNULL(X ^ MASK))
-
char *
strchr (const char *s1,
int i)
{
- const unsigned char *s = (const unsigned char *)s1;
- unsigned char c = i;
-
-#if !defined(PREFER_SIZE_OVER_SPEED) && !defined(__OPTIMIZE_SIZE__)
- unsigned long mask,j;
- unsigned long *aligned_addr;
-
- /* Special case for finding 0. */
- if (!c)
- {
- while (UNALIGNED (s))
- {
- if (!*s)
- return (char *) s;
- s++;
- }
- /* Operate a word at a time. */
- aligned_addr = (unsigned long *) s;
- while (!DETECTNULL (*aligned_addr))
- aligned_addr++;
- /* Found the end of string. */
- s = (const unsigned char *) aligned_addr;
- while (*s)
- s++;
- return (char *) s;
- }
-
- /* All other bytes. Align the pointer, then search a long at a time. */
- while (UNALIGNED (s))
- {
- if (!*s)
- return NULL;
- if (*s == c)
- return (char *) s;
- s++;
- }
-
- mask = c;
- for (j = 8; j < LBLOCKSIZE * 8; j <<= 1)
- mask = (mask << j) | mask;
-
- aligned_addr = (unsigned long *) s;
- while (!DETECTNULL (*aligned_addr) && !DETECTCHAR (*aligned_addr, mask))
- aligned_addr++;
-
- /* The block of bytes currently pointed to by aligned_addr
- contains either a null or the target char, or both. We
- catch it using the bytewise search. */
-
- s = (unsigned char *) aligned_addr;
-
-#endif /* not PREFER_SIZE_OVER_SPEED */
-
- while (*s && *s != c)
- s++;
- if (*s == c)
- return (char *)s;
- return NULL;
+ s1 = strchrnul(s1, i);
+ return s1 && *s1 ? (char *) s1 : NULL;
}
diff --git a/newlib/libc/string/strchrnul.c b/newlib/libc/string/strchrnul.c
index f5c3eb25d..69f66db63 100644
--- a/newlib/libc/string/strchrnul.c
+++ b/newlib/libc/string/strchrnul.c
@@ -29,12 +29,85 @@ QUICKREF
*/
#include <string.h>
+#include <limits.h>
+
+/* Nonzero if X is not aligned on a "long" boundary. */
+#define UNALIGNED(X) ((long)X & (sizeof (long) - 1))
+
+/* How many bytes are loaded each iteration of the word copy loop. */
+#define LBLOCKSIZE (sizeof (long))
+
+#if LONG_MAX == 2147483647L
+#define DETECTNULL(X) (((X) - 0x01010101) & ~(X) & 0x80808080)
+#else
+#if LONG_MAX == 9223372036854775807L
+/* Nonzero if X (a long int) contains a NULL byte. */
+#define DETECTNULL(X) (((X) - 0x0101010101010101) & ~(X) & 0x8080808080808080)
+#else
+#error long int is not a 32bit or 64bit type.
+#endif
+#endif
+
+/* DETECTCHAR returns nonzero if (long)X contains the byte used
+ to fill (long)MASK. */
+#define DETECTCHAR(X,MASK) (DETECTNULL(X ^ MASK))
char *
strchrnul (const char *s1,
int i)
{
- char *s = strchr(s1, i);
+ const unsigned char *s = (const unsigned char *)s1;
+ unsigned char c = i;
+
+#if !defined(PREFER_SIZE_OVER_SPEED) && !defined(__OPTIMIZE_SIZE__)
+ unsigned long mask,j;
+ unsigned long *aligned_addr;
+
+ /* Special case for finding 0. */
+ if (!c)
+ {
+ while (UNALIGNED (s))
+ {
+ if (!*s)
+ return (char *) s;
+ s++;
+ }
+ /* Operate a word at a time. */
+ aligned_addr = (unsigned long *) s;
+ while (!DETECTNULL (*aligned_addr))
+ aligned_addr++;
+ /* Found the end of string. */
+ s = (const unsigned char *) aligned_addr;
+ while (*s)
+ s++;
+ return (char *) s;
+ }
+
+ /* All other bytes. Align the pointer, then search a long at a time. */
+ while (UNALIGNED (s))
+ {
+ if (!*s || *s == c)
+ return (char *) s;
+ s++;
+ }
+
+ mask = c;
+ for (j = 8; j < LBLOCKSIZE * 8; j <<= 1)
+ mask = (mask << j) | mask;
+
+ aligned_addr = (unsigned long *) s;
+ while (!DETECTNULL (*aligned_addr) && !DETECTCHAR (*aligned_addr, mask))
+ aligned_addr++;
+
+ /* The block of bytes currently pointed to by aligned_addr
+ contains either a null or the target char, or both. We
+ catch it using the bytewise search. */
+
+ s = (unsigned char *) aligned_addr;
+
+#endif /* not PREFER_SIZE_OVER_SPEED */
- return s ? s : (char *)s1 + strlen(s1);
+ while (*s && *s != c)
+ s++;
+ return (char *) s;
}
--
2.43.0
next reply other threads:[~2023-12-05 15:02 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-05 14:58 James Tirta Halim [this message]
2023-12-05 15:23 ` Corinna Vinschen
2023-12-05 15:52 ` James
2023-12-05 16:39 ` Richard Earnshaw
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