source: asp3_tinet_ecnl_rx/trunk/musl-1.1.18/src/math/ilogbl.c@ 337

Last change on this file since 337 was 337, checked in by coas-nagasima, 6 years ago

ASP3版ECNLを追加
  • Property svn:eol-style set to native
  • Property svn:mime-type set to text/x-csrc;charset=UTF-8
File size: 1004 bytes
Line 
1#include <limits.h>
2#include "libm.h"
3
4#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
5int ilogbl(long double x)
6{
7 return ilogb(x);
8}
9#elif LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384
10int ilogbl(long double x)
11{
12 #pragma STDC FENV_ACCESS ON
13 union ldshape u = {x};
14 uint64_t m = u.i.m;
15 int e = u.i.se & 0x7fff;
16
17 if (!e) {
18 if (m == 0) {
19 FORCE_EVAL(0/0.0f);
20 return FP_ILOGB0;
21 }
22 /* subnormal x */
23 for (e = -0x3fff+1; m>>63 == 0; e--, m<<=1);
24 return e;
25 }
26 if (e == 0x7fff) {
27 FORCE_EVAL(0/0.0f);
28 return m<<1 ? FP_ILOGBNAN : INT_MAX;
29 }
30 return e - 0x3fff;
31}
32#elif LDBL_MANT_DIG == 113 && LDBL_MAX_EXP == 16384
33int ilogbl(long double x)
34{
35 #pragma STDC FENV_ACCESS ON
36 union ldshape u = {x};
37 int e = u.i.se & 0x7fff;
38
39 if (!e) {
40 if (x == 0) {
41 FORCE_EVAL(0/0.0f);
42 return FP_ILOGB0;
43 }
44 /* subnormal x */
45 x *= 0x1p120;
46 return ilogbl(x) - 120;
47 }
48 if (e == 0x7fff) {
49 FORCE_EVAL(0/0.0f);
50 u.i.se = 0;
51 return u.f ? FP_ILOGBNAN : INT_MAX;
52 }
53 return e - 0x3fff;
54}
55#endif
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