add comment documenting hard-coded opcode for reading mips thread pointer

This commit is contained in:
Rich Felker 2015-10-15 00:55:41 -04:00
parent 0ba35d69c0
commit 11da520c7a
1 changed files with 1 additions and 0 deletions

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@ -5,6 +5,7 @@ static inline struct pthread *__pthread_self()
__asm__ __volatile__ (".word 0x7c03e83b ; move %0, $3" : "=r" (tp) : : "$3" );
#else
register char *tp __asm__("$3");
/* rdhwr $3,$29 */
__asm__ __volatile__ (".word 0x7c03e83b" : "=r" (tp) );
#endif
return (pthread_t)(tp - 0x7000 - sizeof(struct pthread));