1 /*
2 Copyright (c) 2007 Dave Korn
3
4
5 x87 FP implementation contributed to Newlib by
6 Dave Korn, November 2007. This file is placed in the
7 public domain. Permission to use, copy, modify, and
8 distribute this software is freely granted.
9 */
10 /*
11 * ====================================================
12 * x87 FP implementation contributed to Newlib by
13 * Dave Korn, November 2007. This file is placed in the
14 * public domain. Permission to use, copy, modify, and
15 * distribute this software is freely granted.
16 * ====================================================
17 */
18
19 #if defined(__GNUC__) && !defined(_SOFT_FLOAT)
20
21 #include <math.h>
22
23 /*
24 FUNCTION
25 <<lrint>>, <<lrintf>>, <<lrintl>>---round and convert to long integer
26 INDEX
27 lrint
28 INDEX
29 lrintf
30 INDEX
31 lrintl
32
33 SYNOPSIS
34 #include <math.h>
35 long int lrint(double x);
36 long int lrintf(float x);
37 long int lrintl(long double x);
38
39 DESCRIPTION
40 The <<lrint>>, <<lrintf>> and <<lrintl>> functions round <[x]> to the nearest integer value,
41 according to the current rounding direction. If the rounded value is outside the
42 range of the return type, the numeric result is unspecified. A range error may
43 occur if the magnitude of <[x]> is too large.
44
45 RETURNS
46 These functions return the rounded integer value of <[x]>.
47 <<lrint>>, <<lrintf>> and <<lrintl>> return the result as a long integer.
48
49 PORTABILITY
50 <<lrint>>, <<lrintf>>, and <<lrintl>> are ANSI.
51 <<lrint>> and <<lrintf>> are available on all platforms.
52 <<lrintl>> is only available on i386 platforms when hardware
53 floating point support is available and when compiling with GCC.
54
55 */
56
57 /*
58 * Fast math version of lrint(x)
59 * Return x rounded to integral value according to the prevailing
60 * rounding mode.
61 * Method:
62 * Using inline x87 asms.
63 * Exception:
64 * Governed by x87 FPCR.
65 */
66
_f_lrint(double x)67 long int _f_lrint (double x)
68 {
69 long int _result;
70 __asm__("fistpl %0" : "=m" (_result) : "t" (x) : "st");
71 return _result;
72 }
73
74 #endif /* !__GNUC__ || _SOFT_FLOAT */
75
76
