bswap: Add host endian unaligned access functions

Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
This commit is contained in:
Richard Henderson 2013-01-04 16:39:28 -08:00 committed by Blue Swirl
parent cdfe2851c6
commit 7db2145a68
1 changed files with 50 additions and 1 deletions

View File

@ -226,6 +226,8 @@ static inline uint32_t qemu_bswap_len(uint32_t value, int len)
return bswap32(value) >> (32 - 8 * len);
}
/* Unions for reinterpreting between floats and integers. */
typedef union {
float32 f;
uint32_t l;
@ -309,7 +311,7 @@ typedef union {
* q: 64 bits
*
* endian is:
* (empty): 8 bit access
* (empty): host endian
* be : big endian
* le : little endian
*/
@ -328,6 +330,53 @@ static inline void stb_p(void *ptr, int v)
*(uint8_t *)ptr = v;
}
/* Any compiler worth its salt will turn these memcpy into native unaligned
operations. Thus we don't need to play games with packed attributes, or
inline byte-by-byte stores. */
static inline int lduw_p(const void *ptr)
{
uint16_t r;
memcpy(&r, ptr, sizeof(r));
return r;
}
static inline int ldsw_p(const void *ptr)
{
int16_t r;
memcpy(&r, ptr, sizeof(r));
return r;
}
static inline void stw_p(void *ptr, uint16_t v)
{
memcpy(ptr, &v, sizeof(v));
}
static inline int ldl_p(const void *ptr)
{
int32_t r;
memcpy(&r, ptr, sizeof(r));
return r;
}
static inline void stl_p(void *ptr, uint32_t v)
{
memcpy(ptr, &v, sizeof(v));
}
static inline uint64_t ldq_p(const void *ptr)
{
uint64_t r;
memcpy(&r, ptr, sizeof(r));
return r;
}
static inline void stq_p(void *ptr, uint64_t v)
{
memcpy(ptr, &v, sizeof(v));
}
/* NOTE: on arm, putting 2 in /proc/sys/debug/alignment so that the
kernel handles unaligned load/stores may give better results, but
it is a system wide setting : bad */