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endian_swap.h
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endian_swap.h
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#ifndef ENDIAN_SWAP_H
#define ENDIAN_SWAP_H
#include <stdint.h>
#include <inttypes.h>
#include "assert_helpers.h"
#ifdef BOWTIE_64BIT_INDEX
# define endianSwapU(x) endianSwapU64(x)
# define endianSwapI(x) endianSwapI64(x)
#else
# define endianSwapU(x) endianSwapU32(x)
# define endianSwapI(x) endianSwapI32(x)
#endif
/**
* Return true iff the machine running this program is big-endian.
*/
static inline bool currentlyBigEndian() {
static uint8_t endianCheck[] = {1, 0, 0, 0};
return *((uint32_t*)endianCheck) != 1;
}
/**
* Return copy of uint32_t argument with byte order reversed.
*/
static inline uint32_t endianSwapU32(uint32_t u) {
uint32_t tmp = 0;
tmp |= ((u >> 24) & (0xff << 0));
tmp |= ((u >> 8) & (0xff << 8));
tmp |= ((u << 8) & (0xff << 16));
tmp |= ((u << 24) & (0xff << 24));
return tmp;
}
/**
* Return copy of uint64_t argument with byte order reversed.
*/
static inline uint64_t endianSwapU64(uint64_t u) {
uint64_t tmp = 0;
tmp |= ((u >> 56) & (0xffull << 0));
tmp |= ((u >> 40) & (0xffull << 8));
tmp |= ((u >> 24) & (0xffull << 16));
tmp |= ((u >> 8) & (0xffull << 24));
tmp |= ((u << 8) & (0xffull << 32));
tmp |= ((u << 24) & (0xffull << 40));
tmp |= ((u << 40) & (0xffull << 48));
tmp |= ((u << 56) & (0xffull << 56));
return tmp;
}
/**
* Return copy of int32_t argument with byte order reversed.
*/
static inline int32_t endianSwapI32(int32_t i) {
int32_t tmp = 0;
tmp |= ((i >> 24) & (0xff << 0));
tmp |= ((i >> 8) & (0xff << 8));
tmp |= ((i << 8) & (0xff << 16));
tmp |= ((i << 24) & (0xff << 24));
return tmp;
}
/**
* Return copy of int64_t argument with byte order reversed.
*/
static inline int64_t endianSwapI64(int64_t u) {
int64_t tmp = 0;
tmp |= ((u >> 56) & (0xffull << 0));
tmp |= ((u >> 40) & (0xffull << 8));
tmp |= ((u >> 24) & (0xffull << 16));
tmp |= ((u >> 8) & (0xffull << 24));
tmp |= ((u << 8) & (0xffull << 32));
tmp |= ((u << 24) & (0xffull << 40));
tmp |= ((u << 40) & (0xffull << 48));
tmp |= ((u << 56) & (0xffull << 56));
return tmp;
}
/**
* Convert uint32_t/uint64_t argument to the specified endianness. It's assumed
* that u currently has the endianness of the current machine.
*/
template <typename T>
static inline T endianizeU(T u, bool toBig) {
if(toBig == currentlyBigEndian()) {
return u;
}
if(sizeof(T) == 4) {
return endianSwapU32((uint32_t)u);
} else if(sizeof(T) == 8) {
return endianSwapU64((uint64_t)u);
} else {
assert(false);
}
}
/**
* Convert int32_t/int64_t argument to the specified endianness. It's assumed
* that u currently has the endianness of the current machine.
*/
template <typename T>
static inline T endianizeI(T i, bool toBig) {
if(toBig == currentlyBigEndian()) {
return i;
}
if(sizeof(T) == 4) {
return endianSwapI32((int32_t)i);
} else if(sizeof(T) == 8) {
return endianSwapI64((int64_t)i);
} else {
assert(false);
}
}
#endif