diff options
Diffstat (limited to 'src/arch')
| -rw-r--r-- | src/arch/x86/core/x86_string.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/src/arch/x86/core/x86_string.c b/src/arch/x86/core/x86_string.c index 7d5e4a5f1..1a1e79dac 100644 --- a/src/arch/x86/core/x86_string.c +++ b/src/arch/x86/core/x86_string.c @@ -30,6 +30,14 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL ); #include <string.h> +#include <config/defaults.h> + +/* Use generic_memcpy_reverse() if we cannot safely set the direction flag */ +#ifdef UNSAFE_STD +#define USE_GENERIC_MEMCPY_REVERSE 1 +#else +#define USE_GENERIC_MEMCPY_REVERSE 0 +#endif /** * Copy memory area @@ -77,6 +85,12 @@ void * __attribute__ (( noinline )) __memcpy_reverse ( void *dest, const void *esi = ( src + len - 1 ); int discard_ecx; + /* Use unoptimised version if we are not permitted to modify + * the direction flag. + */ + if ( USE_GENERIC_MEMCPY_REVERSE ) + return generic_memcpy_reverse ( dest, src, len ); + /* Assume memmove() is not performance-critical, and perform a * bytewise copy for simplicity. */ |