[kaffe] kafee ARM code question

[G.Madhusudan]

Kaffe 1.1.6

config/arm/threads.h has
#if defined(__XSCALE__) || defined(HAVE_XSCALE)
#define SP_OFFSET       20
#else
#define SP_OFFSET       23
#endif /* defined(__XSCALE__) || defined(HAVE_XSCALE) */


whereas
config/arm/linux/md.h has
#if defined(__XSCALE__) || defined(HAVE_XSCALE)
#define SP_OFFSET   20
#else
#define SP_OFFSET   8
#endif /* defined(__XSCALE__) || defined(HAVE_XSCALE) */

Can someone explain why the SP_OFFSET is different in these two files
for the ARM (non XSCALE) case?