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[PATCH] Add rawmemchr


Code is based on memchr.c; patch for newlib attached.


Yaakov
Cygwin/X
2013-06-23  Yaakov Selkowitz  <yselkowitz@...>

	* libc/include/string.h (rawmemchr): Declare.
	* libc/string/Makefile.am (ELIX_4_SOURCES): Add rawmemchr.c.
	(CHEWOUT_FILES): Add rawmemchr.def.
	* libc/string/Makefile.in: Regenerate.
	* libc/string/rawmemchr.c: New file.

Index: libc/include/string.h
===================================================================
RCS file: /cvs/src/src/newlib/libc/include/string.h,v
retrieving revision 1.33
diff -u -p -r1.33 string.h
--- libc/include/string.h	12 Jan 2013 10:55:09 -0000	1.33
+++ libc/include/string.h	24 Jun 2013 04:32:14 -0000
@@ -57,6 +57,7 @@ _PTR	 _EXFUN(memccpy,(_PTR, const _PTR, 
 _PTR	 _EXFUN(mempcpy,(_PTR, const _PTR, size_t));
 _PTR	 _EXFUN(memmem, (const _PTR, size_t, const _PTR, size_t));
 _PTR 	 _EXFUN(memrchr,(const _PTR, int, size_t));
+_PTR 	 _EXFUN(rawmemchr,(const _PTR, int));
 char 	*_EXFUN(rindex,(const char *, int));
 char 	*_EXFUN(stpcpy,(char *, const char *));
 char 	*_EXFUN(stpncpy,(char *, const char *, size_t));
Index: libc/string/Makefile.am
===================================================================
RCS file: /cvs/src/src/newlib/libc/string/Makefile.am,v
retrieving revision 1.29
diff -u -p -r1.29 Makefile.am
--- libc/string/Makefile.am	10 May 2012 08:34:08 -0000	1.29
+++ libc/string/Makefile.am	24 Jun 2013 04:32:14 -0000
@@ -104,6 +104,7 @@ else
 ELIX_4_SOURCES = \
 	memmem.c \
 	memrchr.c \
+	rawmemchr.c \
 	wcscasecmp.c \
 	wcsncasecmp.c
 endif !ELIX_LEVEL_3
@@ -141,7 +142,7 @@ wcsncmp.def	wcsncpy.def	wcsnlen.def	wcsp
 wcsrchr.def	wcsspn.def	wcsstr.def 	wcstok.def  \
 wcswidth.def	wcsxfrm.def	wcwidth.def	wmemchr.def \
 wmemcmp.def	wmemcpy.def	wmemmove.def	wmemset.def \
-memmem.def	memrchr.def
+memmem.def	memrchr.def	rawmemchr.def
 
 SUFFIXES = .def
 
Index: libc/string/Makefile.in
===================================================================
RCS file: /cvs/src/src/newlib/libc/string/Makefile.in,v
retrieving revision 1.47
diff -u -p -r1.47 Makefile.in
--- libc/string/Makefile.in	20 Dec 2012 21:10:07 -0000	1.47
+++ libc/string/Makefile.in	24 Jun 2013 04:32:15 -0000
@@ -120,6 +120,7 @@ am__objects_1 = lib_a-bcopy.$(OBJEXT) li
 @ELIX_LEVEL_1_FALSE@	lib_a-wcsdup.$(OBJEXT)
 @ELIX_LEVEL_1_FALSE@@ELIX_LEVEL_2_FALSE@@ELIX_LEVEL_3_FALSE@am__objects_3 = lib_a-memmem.$(OBJEXT) \
 @ELIX_LEVEL_1_FALSE@@ELIX_LEVEL_2_FALSE@@ELIX_LEVEL_3_FALSE@	lib_a-memrchr.$(OBJEXT) \
+@ELIX_LEVEL_1_FALSE@@ELIX_LEVEL_2_FALSE@@ELIX_LEVEL_3_FALSE@	lib_a-rawmemchr.$(OBJEXT) \
 @ELIX_LEVEL_1_FALSE@@ELIX_LEVEL_2_FALSE@@ELIX_LEVEL_3_FALSE@	lib_a-wcscasecmp.$(OBJEXT) \
 @ELIX_LEVEL_1_FALSE@@ELIX_LEVEL_2_FALSE@@ELIX_LEVEL_3_FALSE@	lib_a-wcsncasecmp.$(OBJEXT)
 @USE_LIBTOOL_FALSE@am_lib_a_OBJECTS = $(am__objects_1) \
@@ -146,6 +147,7 @@ am__objects_4 = bcopy.lo bzero.lo index.
 @ELIX_LEVEL_1_FALSE@	wcpcpy.lo wcpncpy.lo wcsdup.lo
 @ELIX_LEVEL_1_FALSE@@ELIX_LEVEL_2_FALSE@@ELIX_LEVEL_3_FALSE@am__objects_6 = memmem.lo \
 @ELIX_LEVEL_1_FALSE@@ELIX_LEVEL_2_FALSE@@ELIX_LEVEL_3_FALSE@	memrchr.lo \
+@ELIX_LEVEL_1_FALSE@@ELIX_LEVEL_2_FALSE@@ELIX_LEVEL_3_FALSE@	rawmemchr.lo \
 @ELIX_LEVEL_1_FALSE@@ELIX_LEVEL_2_FALSE@@ELIX_LEVEL_3_FALSE@	wcscasecmp.lo \
 @ELIX_LEVEL_1_FALSE@@ELIX_LEVEL_2_FALSE@@ELIX_LEVEL_3_FALSE@	wcsncasecmp.lo
 @USE_LIBTOOL_TRUE@am_libstring_la_OBJECTS = $(am__objects_4) \
@@ -410,6 +412,7 @@ GENERAL_SOURCES = \
 @ELIX_LEVEL_1_FALSE@@ELIX_LEVEL_2_FALSE@@ELIX_LEVEL_3_FALSE@ELIX_4_SOURCES = \
 @ELIX_LEVEL_1_FALSE@@ELIX_LEVEL_2_FALSE@@ELIX_LEVEL_3_FALSE@	memmem.c \
 @ELIX_LEVEL_1_FALSE@@ELIX_LEVEL_2_FALSE@@ELIX_LEVEL_3_FALSE@	memrchr.c \
+@ELIX_LEVEL_1_FALSE@@ELIX_LEVEL_2_FALSE@@ELIX_LEVEL_3_FALSE@	rawmemchr.c \
 @ELIX_LEVEL_1_FALSE@@ELIX_LEVEL_2_FALSE@@ELIX_LEVEL_3_FALSE@	wcscasecmp.c \
 @ELIX_LEVEL_1_FALSE@@ELIX_LEVEL_2_FALSE@@ELIX_LEVEL_3_FALSE@	wcsncasecmp.c
 
@@ -440,7 +443,7 @@ wcsncmp.def	wcsncpy.def	wcsnlen.def	wcsp
 wcsrchr.def	wcsspn.def	wcsstr.def 	wcstok.def  \
 wcswidth.def	wcsxfrm.def	wcwidth.def	wmemchr.def \
 wmemcmp.def	wmemcpy.def	wmemmove.def	wmemset.def \
-memmem.def	memrchr.def
+memmem.def	memrchr.def	rawmemchr.def
 
 SUFFIXES = .def
 CHEW = ../../doc/makedoc -f $(srcdir)/../../doc/doc.str
@@ -1007,6 +1010,12 @@ lib_a-memrchr.o: memrchr.c
 lib_a-memrchr.obj: memrchr.c
 	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CFLAGS) $(CFLAGS) -c -o lib_a-memrchr.obj `if test -f 'memrchr.c'; then $(CYGPATH_W) 'memrchr.c'; else $(CYGPATH_W) '$(srcdir)/memrchr.c'; fi`
 
+lib_a-rawmemchr.o: rawmemchr.c
+	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CFLAGS) $(CFLAGS) -c -o lib_a-rawmemchr.o `test -f 'rawmemchr.c' || echo '$(srcdir)/'`rawmemchr.c
+
+lib_a-rawmemchr.obj: rawmemchr.c
+	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CFLAGS) $(CFLAGS) -c -o lib_a-rawmemchr.obj `if test -f 'rawmemchr.c'; then $(CYGPATH_W) 'rawmemchr.c'; else $(CYGPATH_W) '$(srcdir)/rawmemchr.c'; fi`
+
 lib_a-wcscasecmp.o: wcscasecmp.c
 	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CFLAGS) $(CFLAGS) -c -o lib_a-wcscasecmp.o `test -f 'wcscasecmp.c' || echo '$(srcdir)/'`wcscasecmp.c
 
Index: libc/string/rawmemchr.c
===================================================================
RCS file: libc/string/rawmemchr.c
diff -N libc/string/rawmemchr.c
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ libc/string/rawmemchr.c	24 Jun 2013 04:32:15 -0000
@@ -0,0 +1,121 @@
+/*
+FUNCTION
+	<<rawmemchr>>---find character in memory
+
+INDEX
+	rawmemchr
+
+ANSI_SYNOPSIS
+	#include <string.h>
+	void *rawmemchr(const void *<[src]>, int <[c]>);
+
+TRAD_SYNOPSIS
+	#include <string.h>
+	void *rawmemchr(<[src]>, <[c]>)
+	void *<[src]>;
+	void *<[c]>;
+
+DESCRIPTION
+	This function searches memory starting at <<*<[src]>>> for the
+	character <[c]>.  The search only ends with the first occurrence
+	of <[c]>; in particular, <<NUL>> does not terminate the search.
+	No bounds checking is performed, so this function should only
+	be used when it is certain that the character <[c]> will be found.
+
+RETURNS
+	A pointer to the first occurance of character <[c]>.
+
+PORTABILITY
+<<rawmemchr>> is a GNU extension.
+
+<<rawmemchr>> requires no supporting OS subroutines.
+
+QUICKREF
+	rawmemchr
+*/
+
+#include <_ansi.h>
+#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))
+
+/* Threshhold for punting to the bytewise iterator.  */
+#define TOO_SMALL(LEN)  ((LEN) < LBLOCKSIZE)
+
+#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
+
+#ifndef DETECTNULL
+#error long int is not a 32bit or 64bit byte
+#endif
+
+/* DETECTCHAR returns nonzero if (long)X contains the byte used
+   to fill (long)MASK. */
+#define DETECTCHAR(X,MASK) (DETECTNULL(X ^ MASK))
+
+_PTR
+_DEFUN (rawmemchr, (src_void, c),
+	_CONST _PTR src_void _AND
+	int c)
+{
+  _CONST unsigned char *src = (_CONST unsigned char *) src_void;
+  unsigned char d = c;
+
+#if !defined(PREFER_SIZE_OVER_SPEED) && !defined(__OPTIMIZE_SIZE__)
+  unsigned long *asrc;
+  unsigned long  mask;
+  int i;
+
+  while (UNALIGNED (src))
+    {
+      if (*src == d)
+        return (void *) src;
+      src++;
+    }
+
+  /* If we get this far, we know that src is word-aligned. */
+  /* The fast code reads the source one word at a time and only
+     performs the bytewise search on word-sized segments if they
+     contain the search character, which is detected by XORing
+     the word-sized segment with a word-sized block of the search
+     character and then detecting for the presence of NUL in the
+     result.  */
+  asrc = (unsigned long *) src;
+  mask = d << 8 | d;
+  mask = mask << 16 | mask;
+  for (i = 32; i < LBLOCKSIZE * 8; i <<= 1)
+    mask = (mask << i) | mask;
+
+  while (1)
+    {
+      if (DETECTCHAR (*asrc, mask))
+        break;
+      asrc++;
+    }
+
+  /* We have the matching word, now we resort to a bytewise loop. */
+
+  src = (unsigned char *) asrc;
+
+#endif // !PREFER_SIZE_OVER_SPEED && !__OPTIMIZE_SIZE__
+
+  while (1)
+    {
+      if (*src == d)
+        return (void *) src;
+      src++;
+    }
+}

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