FastCRC_cpu.h

00001 /* FastCRC library code is placed under the MIT license
00002  * Copyright (c) 2014,2015 Frank Bösing
00003  *
00004  * Permission is hereby granted, free of charge, to any person obtaining
00005  * a copy of this software and associated documentation files (the
00006  * "Software"), to deal in the Software without restriction, including
00007  * without limitation the rights to use, copy, modify, merge, publish,
00008  * distribute, sublicense, and/or sell copies of the Software, and to
00009  * permit persons to whom the Software is furnished to do so, subject to
00010  * the following conditions:
00011  *
00012  * The above copyright notice and this permission notice shall be
00013  * included in all copies or substantial portions of the Software.
00014  *
00015  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
00016  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
00017  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
00018  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
00019  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
00020  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
00021  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
00022  * SOFTWARE.
00023  */
00024 
00025  
00026 // CPU-specific implementations of helper functions
00027 
00028 #if !defined(__CORTEX_M4) 
00029 #if !defined(FastCRC_cpu)
00030 #define FastCRC_cpu
00031 
00032 //Reverse byte order (16 bit)
00033 #if defined(__thumb__)  
00034 static __attribute__((section(".rev16_text"))) __INLINE __ASM uint32_t REV16(uint32_t value)
00035 {
00036   rev16 r0, r0
00037   bx lr
00038 }
00039 #else
00040 static inline __attribute__((always_inline)) 
00041 unsigned int REV16( unsigned int value) //generic
00042 {
00043     return (value >> 8) | ((value & 0xff) << 8);
00044 }
00045 #endif
00046 
00047 
00048 
00049 
00050 
00051 //Reverse byte order (32 bit)
00052 #if defined(__thumb__) 
00053 static __attribute__((section(".rev16_text"))) __INLINE __ASM uint32_t REV32(uint32_t value)
00054 {
00055   rev r0, r0
00056   bx lr
00057 }
00058 #else
00059 static inline  __attribute__((always_inline))
00060 unsigned int REV32( unsigned int value) //generic
00061 {
00062     value = (value >> 16) | ((value & 0xffff) << 16);
00063     return ((value >> 8) & 0xff00ff) | ((value & 0xff00ff) << 8);
00064 }
00065 #endif
00066 
00067 
00068 #endif
00069 #endif