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| author | Michael Brown | 2012-03-04 22:41:24 +0100 |
|---|---|---|
| committer | Michael Brown | 2012-03-04 22:41:24 +0100 |
| commit | 732bea2f88d0d471e396831b19d2d5d40833c41c (patch) | |
| tree | 9280045a258fe7932f617a79f70a76ab1211b9d7 /src/arch/i386/include/bits | |
| parent | [i386] Fix building on older versions of gcc (diff) | |
| download | ipxe-732bea2f88d0d471e396831b19d2d5d40833c41c.tar.gz ipxe-732bea2f88d0d471e396831b19d2d5d40833c41c.tar.xz ipxe-732bea2f88d0d471e396831b19d2d5d40833c41c.zip | |
[i386] Use memory address constraints in __bswap_16s() and __bswap_64s()
Minimise code size by forcing the use of memory addresses for
__bswap_16s() and __bswap_64s(). (__bswap_32s() cannot avoid loading the
value into a register.)
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Diffstat (limited to 'src/arch/i386/include/bits')
| -rw-r--r-- | src/arch/i386/include/bits/byteswap.h | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/src/arch/i386/include/bits/byteswap.h b/src/arch/i386/include/bits/byteswap.h index d40771354..f3d30a254 100644 --- a/src/arch/i386/include/bits/byteswap.h +++ b/src/arch/i386/include/bits/byteswap.h @@ -19,7 +19,7 @@ __bswap_variable_16 ( uint16_t x ) { static inline __attribute__ (( always_inline )) void __bswap_16s ( uint16_t *x ) { - __asm__ ( "rorw $8, %0" : "=g" ( *x ) : "0" ( *x ) ); + __asm__ ( "rorw $8, %0" : "+m" ( *x ) ); } static inline __attribute__ (( always_inline, const )) uint32_t @@ -63,9 +63,8 @@ __bswap_64s ( uint64_t *x ) { "xchgl %2,%1\n\t" "bswapl %2\n\t" "movl %2,%0\n\t" - : "=g" ( dwords->low ), "=g" ( dwords->high ), - "=r" ( discard ) - : "0" ( dwords->low ), "1" ( dwords->high ) ); + : "+m" ( dwords->low ), "+m" ( dwords->high ), + "=r" ( discard ) ); } #endif /* _BITS_BYTESWAP_H */ |