1 //===========================================================================
5 // ANSI standard memcmp() routine
7 //===========================================================================
8 //####ECOSGPLCOPYRIGHTBEGIN####
9 // -------------------------------------------
10 // This file is part of eCos, the Embedded Configurable Operating System.
11 // Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.
13 // eCos is free software; you can redistribute it and/or modify it under
14 // the terms of the GNU General Public License as published by the Free
15 // Software Foundation; either version 2 or (at your option) any later version.
17 // eCos is distributed in the hope that it will be useful, but WITHOUT ANY
18 // WARRANTY; without even the implied warranty of MERCHANTABILITY or
19 // FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
22 // You should have received a copy of the GNU General Public License along
23 // with eCos; if not, write to the Free Software Foundation, Inc.,
24 // 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
26 // As a special exception, if other files instantiate templates or use macros
27 // or inline functions from this file, or you compile this file and link it
28 // with other works to produce a work based on this file, this file does not
29 // by itself cause the resulting work to be covered by the GNU General Public
30 // License. However the source code for this file must still be made available
31 // in accordance with section (3) of the GNU General Public License.
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34 // this file might be covered by the GNU General Public License.
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37 // at http://sources.redhat.com/ecos/ecos-license/
38 // -------------------------------------------
39 //####ECOSGPLCOPYRIGHTEND####
40 //===========================================================================
41 //#####DESCRIPTIONBEGIN####
43 // Author(s): jlarmour
50 //####DESCRIPTIONEND####
52 //===========================================================================
56 #include <pkgconf/libc_string.h> // Configuration header
60 #include <cyg/infra/cyg_type.h> // Common type definitions
61 #include <cyg/infra/cyg_trac.h> // Tracing support
62 #include <cyg/infra/cyg_ass.h> // Assertion support
63 #include <string.h> // Header for this file
64 #include <stddef.h> // Compiler definitions such as size_t, NULL etc.
65 #include <cyg/libc/string/stringsupp.hxx> // Useful string function support and
72 memcmp( const void *s1, const void *s2, size_t n ) \
73 CYGBLD_ATTRIB_WEAK_ALIAS(__memcmp);
78 __memcmp( const void *s1, const void *s2, size_t n )
82 CYG_REPORT_FUNCNAMETYPE( "__memcmp", "returning %d" );
83 CYG_REPORT_FUNCARG3( "s1=%08x, s2=%08x, n=%d", s1, s2, n );
87 CYG_CHECK_DATA_PTR( s1, "s1 is not a valid pointer!" );
88 CYG_CHECK_DATA_PTR( s2, "s2 is not a valid pointer!" );
91 #if defined(CYGIMP_LIBC_STRING_PREFER_SMALL_TO_FAST) || defined(__OPTIMIZE_SIZE__)
92 const unsigned char *m1 = (const unsigned char *) s1;
93 const unsigned char *m2 = (const unsigned char *) s2;
100 CYG_REPORT_RETVAL( retval );
106 CYG_REPORT_RETVAL( 0 );
109 const unsigned char *m1 = (const unsigned char *) s1;
110 const unsigned char *m2 = (const unsigned char *) s2;
111 const CYG_WORD *aligned_m1;
112 const CYG_WORD *aligned_m2;
114 // If the size is too small, or either pointer is unaligned,
115 // then we punt to the byte compare loop. Hopefully this will
116 // not turn up in inner loops.
117 if (CYG_LIBC_STR_OPT_TOO_SMALL(n) || CYG_LIBC_STR_UNALIGNED2(m1,m2))
124 CYG_REPORT_RETVAL( retval );
130 CYG_REPORT_RETVAL( 0 );
134 // Otherwise, load and compare the blocks of memory one
136 aligned_m1 = (const CYG_WORD *) m1;
137 aligned_m2 = (const CYG_WORD *) m2;
138 while (n > CYG_LIBC_STR_OPT_LITTLEBLOCKSIZE)
140 if (*aligned_m1 != *aligned_m2)
142 // This block of characters has a mismatch, somewhere.
143 // xoring them together and then testing for null would
144 // be fastest, but this is clearer code.
145 m1 = (const unsigned char *)aligned_m1;
146 m2 = (const unsigned char *)aligned_m2;
152 CYG_REPORT_RETVAL( retval );
162 n -= CYG_LIBC_STR_OPT_LITTLEBLOCKSIZE;
165 // checking the last few characters
167 m1 = (const unsigned char *)aligned_m1;
168 m2 = (const unsigned char *)aligned_m2;
175 CYG_REPORT_RETVAL( retval );
182 CYG_REPORT_RETVAL( 0 );
184 #endif // not defined(CYGIMP_LIBC_STRING_PREFER_SMALL_TO_FAST) ||
185 // defined(__OPTIMIZE_SIZE__)