/*=========================================================================== // // memset.c // // ANSI standard memset() routine // //========================================================================== //####COPYRIGHTBEGIN#### // // ------------------------------------------- // The contents of this file are subject to the Red Hat eCos Public License // Version 1.1 (the "License"); you may not use this file except in // compliance with the License. You may obtain a copy of the License at // http://www.redhat.com/ // // Software distributed under the License is distributed on an "AS IS" // basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the // License for the specific language governing rights and limitations under // the License. // // The Original Code is eCos - Embedded Configurable Operating System, // released September 30, 1998. // // The Initial Developer of the Original Code is Red Hat. // Portions created by Red Hat are // Copyright (C) 1998, 1999, 2000 Red Hat, Inc. // All Rights Reserved. // ------------------------------------------- // //####COPYRIGHTEND#### //========================================================================== //#####DESCRIPTIONBEGIN#### // // Author(s): jlarmour // Contributors: jlarmour // Date: 1998-06-04 // Purpose: This file implements the ANSI memset() function // Description: This file implements the memset() function defined in ANSI para // 7.11.6.1. This is implemented in the kernel rather than the // C library due to it being required by gcc whether or not the // C library has been configured in. // //####DESCRIPTIONEND#### // //==========================================================================*/ /* INCLUDES */ #include /* Configuration of infra package */ #include /* Common type definitions */ #include /* Tracing support */ #include /* Assertion support */ #include /* Compiler defns such as size_t, NULL etc. */ /* MACROS */ /* Nonzero if X is not aligned on a word boundary. */ #define CYG_STR_UNALIGNED(X) ((CYG_WORD)(X) & (sizeof (CYG_WORD) - 1)) /* How many bytes are copied each iteration of the word copy loop in the * optimised string implementation */ #define CYG_STR_OPT_LITTLEBLOCKSIZE (sizeof (CYG_WORD)) /* EXPORTED SYMBOLS */ externC void * memset( void *s, int c, size_t n ) __attribute__ ((weak, alias("_memset"))); /* FUNCTIONS */ void * _memset( void *s, int c, size_t n ) { #if defined(CYGIMP_INFRA_PREFER_SMALL_TO_FAST_MEMSET) || defined(__OPTIMIZE_SIZE__) char *char_ptr = (char *)s; #ifdef CYG_TRACING_FIXED CYG_REPORT_FUNCNAMETYPE( "_memset", "returning %08x" ); CYG_REPORT_FUNCARG3( "s=%08x, c=%d, n=%d", s, c, n ); if (n != 0) { CYG_CHECK_DATA_PTR( char_ptr, "s is not a valid pointer!" ); CYG_CHECK_DATA_PTR( (&char_ptr[n-1]), "s+n-1 is not a valid address!" ); } #endif while (n-- != 0) { *char_ptr++ = (char) c; } #ifdef CYG_TRACING_FIXED CYG_REPORT_RETVAL( s ); #endif return s; #else char *char_ptr = (char *)s; cyg_ucount8 count; CYG_WORD buffer; CYG_WORD *aligned_addr; char *unaligned_addr; #ifdef CYG_TRACING_FIXED CYG_REPORT_FUNCNAMETYPE( "_memset", "returning %08x" ); CYG_REPORT_FUNCARG3( "s=%08x, c=%d, n=%d", s, c, n ); if (n != 0) { CYG_CHECK_DATA_PTR( s, "s is not a valid pointer!" ); CYG_CHECK_DATA_PTR( (char *)s+n-1, "s+n-1 is not a valid address!" ); } #endif if (n < sizeof(CYG_WORD) || CYG_STR_UNALIGNED (s)) { while (n-- != 0) { *char_ptr++ = (char) c; } #ifdef CYG_TRACING_FIXED CYG_REPORT_RETVAL( s ); #endif return s; } /* If we get this far, we know that n is large and s is word-aligned. */ aligned_addr = (CYG_WORD *)s; /* Store C into each char sized location in BUFFER so that * we can set large blocks quickly. */ c &= 0xff; if (CYG_STR_OPT_LITTLEBLOCKSIZE == 4) { buffer = (c buffer |= (buffer } else { buffer = 0; for (count = 0; count < CYG_STR_OPT_LITTLEBLOCKSIZE; count++) buffer = (buffer } while (n >= CYG_STR_OPT_LITTLEBLOCKSIZE*4) { *aligned_addr++ = buffer; *aligned_addr++ = buffer; *aligned_addr++ = buffer; *aligned_addr++ = buffer; n -= 4*CYG_STR_OPT_LITTLEBLOCKSIZE; } while (n >= CYG_STR_OPT_LITTLEBLOCKSIZE) { *aligned_addr++ = buffer; n -= CYG_STR_OPT_LITTLEBLOCKSIZE; } /* Pick up the remainder with a bytewise loop. */ unaligned_addr = (char*)aligned_addr; while (n) { *unaligned_addr++ = (char)c; n--; } #ifdef CYG_TRACING_FIXED CYG_REPORT_RETVAL( s ); #endif return s; #endif /* not defined(CYGIMP_PREFER_SMALL_TO_FAST_MEMSET) || * defined(__OPTIMIZE_SIZE__) */ } /* _memset() */ /* EOF memset.c */
