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      1 /*	$NetBSD: fpsetround.c,v 1.6 2012/03/23 09:34:09 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 1.6 2012/03/23 09:34:09 skrll Exp $");
     12 #endif /* LIBC_SCCS and not lint */
     13 
     14 #include <sys/types.h>
     15 #include <ieeefp.h>
     16 
     17 fp_rnd
     18 fpsetround(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