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Warning, file /include/root/Bswapcpy.h was not indexed or was modified since last indexation (in which case cross-reference links may be missing, inaccurate or erroneous).
0001 /* @(#)root/base:$Id$ */ 0002 0003 /************************************************************************* 0004 * Copyright (C) 1995-2000, Rene Brun and Fons Rademakers. * 0005 * All rights reserved. * 0006 * * 0007 * For the licensing terms see $ROOTSYS/LICENSE. * 0008 * For the list of contributors see $ROOTSYS/README/CREDITS. * 0009 *************************************************************************/ 0010 #ifndef ROOT_Bswapcpy 0011 #define ROOT_Bswapcpy 0012 0013 ////////////////////////////////////////////////////////////////////////// 0014 // // 0015 // Bswapcpy // 0016 // // 0017 // Initial version: Apr 22, 2000 // 0018 // // 0019 // A set of inline byte swapping routines for arrays. // 0020 // // 0021 // The bswapcpy16() and bswapcpy32() routines are used for packing // 0022 // arrays of basic types into a buffer in a byte swapped order. Use // 0023 // of asm and the `bswap' opcode (available on i486 and up) reduces // 0024 // byte swapping overhead on linux. // 0025 // // 0026 // Use of routines is similar to that of memcpy. // 0027 // // 0028 // ATTENTION: // 0029 // // 0030 // n - is a number of array elements to be copied and byteswapped. // 0031 // (It is not the number of bytes!) // 0032 // // 0033 // Note: It is note safe to call these routines with n == 0. // 0034 // // 0035 // For arrays of short type (2 bytes in size) use bswapcpy16(). // 0036 // For arrays of of 4-byte types (int, float) use bswapcpy32(). // 0037 // // 0038 // // 0039 // Author: Alexandre V. Vaniachine <AVVaniachine@lbl.gov> // 0040 // // 0041 ////////////////////////////////////////////////////////////////////////// 0042 0043 #include <sys/types.h> 0044 0045 extern inline void * bswapcpy16(void * to, const void * from, size_t n) 0046 { 0047 int d0, d1, d2, d3; 0048 __asm__ __volatile__( 0049 "cld\n" 0050 "1:\tlodsw\n\t" 0051 "rorw $8, %%ax\n\t" 0052 "stosw\n\t" 0053 "loop 1b\n\t" 0054 :"=&c" (d0), "=&D" (d1), "=&S" (d2), "=&a" (d3) 0055 :"0" (n), "1" ((long) to),"2" ((long) from) 0056 :"memory"); 0057 return (to); 0058 } 0059 0060 extern inline void * bswapcpy32(void * to, const void * from, size_t n) 0061 { 0062 int d0, d1, d2, d3; 0063 __asm__ __volatile__( 0064 "cld\n" 0065 "1:\tlodsl\n\t" 0066 #if !defined __i486__ && !defined __pentium__ && !defined __pentiumpro__ && \ 0067 !defined __pentium4__ && !defined __x86_64__ 0068 "rorw $8, %%ax\n\t" 0069 "rorl $16, %%eax\n\t" 0070 "rorw $8, %%ax\n\t" 0071 #else 0072 "bswap %%eax\n\t" 0073 #endif 0074 "stosl\n\t" 0075 "loop 1b\n\t" 0076 :"=&c" (d0), "=&D" (d1), "=&S" (d2), "=&a" (d3) 0077 :"0" (n), "1" ((long) to),"2" ((long) from) 0078 :"memory"); 0079 return (to); 0080 } 0081 #endif
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