Mercurial > ecos
annotate packages/infra/current/src/memset.c @ 64:c38311975d4f ecos-sw-2000-01-28
Merge from eCos master repository on 2000-01-28-04:28:11-GMT
| author | jlarmour |
|---|---|
| date | Fri, 28 Jan 2000 04:59:39 +0000 |
| parents | 443894e2e912 |
| children | bf00f99aec69 |
| rev | line source |
|---|---|
| 0 | 1 /*=========================================================================== |
| 2 // | |
| 3 // memset.c | |
| 4 // | |
| 5 // ANSI standard memset() routine | |
| 6 // | |
| 7 //========================================================================== | |
| 8 //####COPYRIGHTBEGIN#### | |
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9 // |
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10 // ------------------------------------------- |
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11 // The contents of this file are subject to the Red Hat eCos Public License |
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12 // Version 1.0 (the "License"); you may not use this file except in |
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13 // compliance with the License. You may obtain a copy of the License at |
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14 // http://sourceware.cygnus.com/ecos |
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15 // |
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16 // Software distributed under the License is distributed on an |
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17 // basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the |
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18 // License for the specific language governing rights and limitations under |
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19 // the License. |
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20 // |
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21 // The Original Code is eCos - Embedded Configurable Operating System, |
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22 // released September 30, 1998. |
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23 // |
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24 // The Initial Developer of the Original Code is Red Hat. |
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25 // Portions created by Red Hat are |
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26 // Copyright (C) 1998, 1999, 2000 Red Hat, Inc. |
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27 // All Rights Reserved. |
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28 // ------------------------------------------- |
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29 // |
| 0 | 30 //####COPYRIGHTEND#### |
| 31 //========================================================================== | |
| 32 //#####DESCRIPTIONBEGIN#### | |
| 33 // | |
| 2 | 34 // Author(s): jlarmour |
| 35 // Contributors: jlarmour | |
| 0 | 36 // Date: 1998-06-04 |
| 37 // Purpose: This file implements the ANSI memset() function | |
| 38 // Description: This file implements the memset() function defined in ANSI para | |
| 39 // 7.11.6.1. This is implemented in the kernel rather than the | |
| 40 // C library due to it being required by gcc whether or not the | |
| 41 // C library has been configured in. | |
| 42 // | |
| 43 //####DESCRIPTIONEND#### | |
| 44 // | |
| 45 //==========================================================================*/ | |
| 46 | |
| 47 | |
| 48 /* INCLUDES */ | |
| 49 | |
| 50 #include <pkgconf/infra.h> /* Configuration of infra package */ | |
| 51 | |
| 52 #include <cyg/infra/cyg_type.h> /* Common type definitions */ | |
| 53 #include <cyg/infra/cyg_trac.h> /* Tracing support */ | |
| 54 #include <cyg/infra/cyg_ass.h> /* Assertion support */ | |
| 55 #include <stddef.h> /* Compiler defns such as size_t, NULL etc. */ | |
| 56 | |
| 57 /* MACROS */ | |
| 58 | |
| 59 /* Nonzero if X is not aligned on a word boundary. */ | |
| 60 #define CYG_STR_UNALIGNED(X) ((CYG_WORD)(X) & (sizeof (CYG_WORD) - 1)) | |
| 61 | |
| 62 /* How many bytes are copied each iteration of the word copy loop in the | |
| 63 * optimised string implementation | |
| 64 */ | |
| 65 #define CYG_STR_OPT_LITTLEBLOCKSIZE (sizeof (CYG_WORD)) | |
| 66 | |
| 67 /* EXPORTED SYMBOLS */ | |
| 68 | |
| 69 externC void * | |
| 70 memset( void *s, int c, size_t n ) __attribute__ ((weak, alias("_memset"))); | |
| 71 | |
| 72 /* FUNCTIONS */ | |
| 73 | |
| 74 void * | |
| 75 _memset( void *s, int c, size_t n ) | |
| 76 { | |
| 77 #if defined(CYGIMP_INFRA_PREFER_SMALL_TO_FAST_MEMSET) || defined(__OPTIMIZE_SIZE__) | |
| 78 char *char_ptr = (char *)s; | |
| 79 | |
| 80 #ifdef CYG_TRACING_FIXED | |
| 81 CYG_REPORT_FUNCNAMETYPE( "_memset", "returning %08x" ); | |
| 82 CYG_REPORT_FUNCARG3( "s=%08x, c=%d, n=%d", s, c, n ); | |
| 83 | |
| 84 if (n != 0) | |
| 85 { | |
| 2 | 86 CYG_CHECK_DATA_PTR( char_ptr, "s is not a valid pointer!" ); |
| 87 CYG_CHECK_DATA_PTR( (&char_ptr[n-1]), "s+n-1 is not a valid address!" ); | |
| 0 | 88 } |
| 89 #endif | |
| 90 | |
| 91 while (n-- != 0) | |
| 92 { | |
| 93 *char_ptr++ = (char) c; | |
| 94 } | |
| 95 | |
| 96 #ifdef CYG_TRACING_FIXED | |
| 97 CYG_REPORT_RETVAL( s ); | |
| 98 #endif | |
| 99 return s; | |
| 100 #else | |
| 101 char *char_ptr = (char *)s; | |
| 102 cyg_ucount8 count; | |
| 103 CYG_WORD buffer; | |
| 104 CYG_WORD *aligned_addr; | |
| 105 char *unaligned_addr; | |
| 106 | |
| 107 #ifdef CYG_TRACING_FIXED | |
| 108 CYG_REPORT_FUNCNAMETYPE( "_memset", "returning %08x" ); | |
| 109 CYG_REPORT_FUNCARG3( "s=%08x, c=%d, n=%d", s, c, n ); | |
| 110 | |
| 111 if (n != 0) | |
| 112 { | |
| 113 CYG_CHECK_DATA_PTR( s, "s is not a valid pointer!" ); | |
| 114 CYG_CHECK_DATA_PTR( (char *)s+n-1, "s+n-1 is not a valid address!" ); | |
| 115 } | |
| 116 #endif | |
| 117 | |
| 118 if (n < sizeof(CYG_WORD) || CYG_STR_UNALIGNED (s)) | |
| 119 { | |
| 120 while (n-- != 0) | |
| 121 { | |
| 122 *char_ptr++ = (char) c; | |
| 123 } | |
| 124 #ifdef CYG_TRACING_FIXED | |
| 125 CYG_REPORT_RETVAL( s ); | |
| 126 #endif | |
| 127 return s; | |
| 128 } | |
| 129 | |
| 130 /* If we get this far, we know that n is large and s is word-aligned. */ | |
| 131 | |
| 132 aligned_addr = (CYG_WORD *)s; | |
| 133 | |
| 134 /* Store C into each char sized location in BUFFER so that | |
| 135 * we can set large blocks quickly. | |
| 136 */ | |
| 137 c &= 0xff; | |
| 138 if (CYG_STR_OPT_LITTLEBLOCKSIZE == 4) | |
| 139 { | |
| 140 buffer = (c << 8) | c; | |
| 141 buffer |= (buffer << 16); | |
| 142 } | |
| 143 else | |
| 144 { | |
| 145 buffer = 0; | |
| 146 for (count = 0; count < CYG_STR_OPT_LITTLEBLOCKSIZE; count++) | |
| 147 buffer = (buffer << 8) | c; | |
| 148 } | |
| 149 | |
| 150 while (n >= CYG_STR_OPT_LITTLEBLOCKSIZE*4) | |
| 151 { | |
| 152 *aligned_addr++ = buffer; | |
| 153 *aligned_addr++ = buffer; | |
| 154 *aligned_addr++ = buffer; | |
| 155 *aligned_addr++ = buffer; | |
| 156 n -= 4*CYG_STR_OPT_LITTLEBLOCKSIZE; | |
| 157 } | |
| 158 | |
| 159 while (n >= CYG_STR_OPT_LITTLEBLOCKSIZE) | |
| 160 { | |
| 161 *aligned_addr++ = buffer; | |
| 162 n -= CYG_STR_OPT_LITTLEBLOCKSIZE; | |
| 163 } | |
| 164 | |
| 165 /* Pick up the remainder with a bytewise loop. */ | |
| 166 unaligned_addr = (char*)aligned_addr; | |
| 167 while (n) | |
| 168 { | |
| 169 *unaligned_addr++ = (char)c; | |
| 170 n--; | |
| 171 } | |
| 172 | |
| 173 #ifdef CYG_TRACING_FIXED | |
| 174 CYG_REPORT_RETVAL( s ); | |
| 175 #endif | |
| 176 return s; | |
| 177 #endif /* not defined(CYGIMP_PREFER_SMALL_TO_FAST_MEMSET) || | |
| 178 * defined(__OPTIMIZE_SIZE__) */ | |
| 179 } /* _memset() */ | |
| 180 | |
| 181 /* EOF memset.c */ |