From 732bea2f88d0d471e396831b19d2d5d40833c41c Mon Sep 17 00:00:00 2001 From: Michael Brown Date: Sun, 4 Mar 2012 21:41:24 +0000 Subject: [PATCH] [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 --- src/arch/i386/include/bits/byteswap.h | 7 +++---- 1 file 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 */