xref: /freebsd/lib/libc/i386/gen/flt_rounds.c (revision 559a218c9b257775fb249b67945fe4a05b7a6b9f)
1479f8d22SDavid Schultz /*
2479f8d22SDavid Schultz  * Written by J.T. Conklin, Apr 10, 1995
3479f8d22SDavid Schultz  * Public domain.
4479f8d22SDavid Schultz  */
5479f8d22SDavid Schultz 
6479f8d22SDavid Schultz #include <float.h>
7479f8d22SDavid Schultz 
8479f8d22SDavid Schultz static const int map[] = {
9479f8d22SDavid Schultz 	1,	/* round to nearest */
10479f8d22SDavid Schultz 	3,	/* round to zero */
11479f8d22SDavid Schultz 	2,	/* round to negative infinity */
12479f8d22SDavid Schultz 	0	/* round to positive infinity */
13479f8d22SDavid Schultz };
14479f8d22SDavid Schultz 
15479f8d22SDavid Schultz int
__flt_rounds(void)16479f8d22SDavid Schultz __flt_rounds(void)
17479f8d22SDavid Schultz {
18479f8d22SDavid Schultz 	int x;
19479f8d22SDavid Schultz 
20479f8d22SDavid Schultz 	__asm("fnstcw %0" : "=m" (x));
21479f8d22SDavid Schultz         return (map[(x >> 10) & 0x03]);
22479f8d22SDavid Schultz }
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