1/* $NetBSD: fpsetround.c,v 1.5 2009/01/25 16:44:41 skrll Exp $ */ 2 3/* $OpenBSD: fpsetround.c,v 1.3 2002/10/21 18:41:05 mickey Exp $ */ 4 5/* 6 * Written by Miodrag Vallat. Public domain 7 */ 8 9#include <sys/cdefs.h> 10#if defined(LIBC_SCCS) && !defined(lint) 11__RCSID("$NetBSD: fpsetround.c,v 1.5 2009/01/25 16:44:41 skrll Exp $"); 12#endif /* LIBC_SCCS and not lint */ 13 14#include <sys/types.h> 15#include <ieeefp.h> 16 17fp_rnd 18fpsetround(fp_rnd rnd_dir) 19{ 20 uint64_t fpsr; 21 fp_rnd old; 22 23 __asm volatile("fstd %%fr0,0(%1)" : "=m" (fpsr) : "r" (&fpsr) : "memory"); 24 old = (fp_rnd)(fpsr >> 41) & 0x03; 25 fpsr = (fpsr & 0xfffff9ff00000000LL) | 26 ((uint64_t)(rnd_dir & 0x03) << 41); 27 __asm volatile("fldd 0(%0),%%fr0" : : "r" (&fpsr) : "memory"); 28 return (old); 29} 30