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Use __builtin_bswap32/64 in x86_64 <bits/byteswap.h>

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H.J. Lu 2012-04-10 12:11:54 -07:00
parent 73d65cc378
commit b46068fcf2
2 changed files with 59 additions and 32 deletions
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6
ChangeLog
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@ -1,3 +1,9 @@
2012-04-10 H.J. Lu <hongjiu.lu@intel.com>
* sysdeps/x86_64/bits/byteswap.h: Include <features.h>.
(__bswap_32): Use __builtin_bswap32 for GCC >= 4.2.
(__bswap_64): Use __builtin_bswap64 for GCC >= 4.2.
2012-04-10 Siddhesh Poyarekar <siddhesh@redhat.com>
* elf/dl-support.c (_dl_inhibit_cache): New variable.

85
sysdeps/x86_64/bits/byteswap.h
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@ -23,6 +23,7 @@
#ifndef _BITS_BYTESWAP_H
#define _BITS_BYTESWAP_H 1
#include <features.h>
#include <bits/wordsize.h>
/* Swap bytes in 16 bit value. */
@ -37,46 +38,60 @@
((((x) & 0xff000000) >> 24) | (((x) & 0x00ff0000) >> 8) | \
(((x) & 0x0000ff00) << 8) | (((x) & 0x000000ff) << 24))
#if defined __GNUC__ && __GNUC__ >= 2
# if __WORDSIZE == 64 || (defined __i486__ || defined __pentium__ \
|| defined __pentiumpro__ || defined __pentium4__ \
|| defined __k8__ || defined __athlon__ \
|| defined __k6__ || defined __nocona__ \
|| defined __core2__ || defined __geode__ \
|| defined __amdfam10__)
#ifdef __GNUC__
# if __GNUC_PREREQ (4, 2)
static __inline unsigned int
__bswap_32 (unsigned int __bsx)
{
return __builtin_bswap32 (__bsx);
}
# elif __GNUC__ >= 2
# if __WORDSIZE == 64 || (defined __i486__ || defined __pentium__ \
|| defined __pentiumpro__ || defined __pentium4__ \
|| defined __k8__ || defined __athlon__ \
|| defined __k6__ || defined __nocona__ \
|| defined __core2__ || defined __geode__ \
|| defined __amdfam10__)
/* To swap the bytes in a word the i486 processors and up provide the
`bswap' opcode. On i386 we have to use three instructions. */
# define __bswap_32(x) \
(__extension__ \
({ register unsigned int __v, __x = (x); \
if (__builtin_constant_p (__x)) \
__v = __bswap_constant_32 (__x); \
else \
__asm__ ("bswap %0" : "=r" (__v) : "0" (__x)); \
__v; }))
# else
# define __bswap_32(x) \
(__extension__ \
({ register unsigned int __v, __x = (x); \
if (__builtin_constant_p (__x)) \
__v = __bswap_constant_32 (__x); \
else \
__asm__ ("rorw $8, %w0;" \
"rorl $16, %0;" \
"rorw $8, %w0" \
: "=r" (__v) \
: "0" (__x) \
: "cc"); \
__v; }))
# endif
# else
# define __bswap_32(x) \
(__extension__ \
({ register unsigned int __v, __x = (x); \
if (__builtin_constant_p (__x)) \
__v = __bswap_constant_32 (__x); \
else \
__asm__ ("bswap %0" : "=r" (__v) : "0" (__x)); \
__v; }))
# else
# define __bswap_32(x) \
(__extension__ \
({ register unsigned int __v, __x = (x); \
if (__builtin_constant_p (__x)) \
__v = __bswap_constant_32 (__x); \
else \
__asm__ ("rorw $8, %w0;" \
"rorl $16, %0;" \
"rorw $8, %w0" \
: "=r" (__v) \
: "0" (__x) \
: "cc"); \
__v; }))
({ register unsigned int __x = (x); __bswap_constant_32 (__x); }))
# endif
#else
# define __bswap_32(x) \
(__extension__ \
({ register unsigned int __x = (x); __bswap_constant_32 (__x); }))
static __inline unsigned int
__bswap_32 (unsigned int __bsx)
{
return __bswap_constant_32 (__bsx);
}
#endif
#if defined __GNUC__ && __GNUC__ >= 2
#if __GNUC_PREREQ (2, 0)
/* Swap bytes in 64 bit value. */
# define __bswap_constant_64(x) \
(__extension__ ((((x) & 0xff00000000000000ull) >> 56) \
@ -88,7 +103,13 @@
| (((x) & 0x000000000000ff00ull) << 40) \
| (((x) & 0x00000000000000ffull) << 56)))
# if __WORDSIZE == 64
# if __GNUC_PREREQ (4, 2)
static __inline unsigned long long int
__bswap_64 (unsigned long long int __bsx)
{
return __builtin_bswap64 (__bsx);
}
# elif __WORDSIZE == 64
# define __bswap_64(x) \
(__extension__ \
({ register unsigned long __v, __x = (x); \