Last change
on this file since 445 was 444, checked in by coas-nagasima, 4 years ago |
muslのソースコードを追加
|
-
Property svn:eol-style
set to
native
-
Property svn:mime-type
set to
text/x-csrc;charset=UTF-8
|
File size:
1.1 KB
|
Line | |
---|
1 | #include <math.h>
|
---|
2 | #include <stdint.h>
|
---|
3 |
|
---|
4 | float fmodf(float x, float y)
|
---|
5 | {
|
---|
6 | union {float f; uint32_t i;} ux = {x}, uy = {y};
|
---|
7 | int ex = ux.i>>23 & 0xff;
|
---|
8 | int ey = uy.i>>23 & 0xff;
|
---|
9 | uint32_t sx = ux.i & 0x80000000;
|
---|
10 | uint32_t i;
|
---|
11 | uint32_t uxi = ux.i;
|
---|
12 |
|
---|
13 | if (uy.i<<1 == 0 || isnan(y) || ex == 0xff)
|
---|
14 | return (x*y)/(x*y);
|
---|
15 | if (uxi<<1 <= uy.i<<1) {
|
---|
16 | if (uxi<<1 == uy.i<<1)
|
---|
17 | return 0*x;
|
---|
18 | return x;
|
---|
19 | }
|
---|
20 |
|
---|
21 | /* normalize x and y */
|
---|
22 | if (!ex) {
|
---|
23 | for (i = uxi<<9; i>>31 == 0; ex--, i <<= 1);
|
---|
24 | uxi <<= -ex + 1;
|
---|
25 | } else {
|
---|
26 | uxi &= -1U >> 9;
|
---|
27 | uxi |= 1U << 23;
|
---|
28 | }
|
---|
29 | if (!ey) {
|
---|
30 | for (i = uy.i<<9; i>>31 == 0; ey--, i <<= 1);
|
---|
31 | uy.i <<= -ey + 1;
|
---|
32 | } else {
|
---|
33 | uy.i &= -1U >> 9;
|
---|
34 | uy.i |= 1U << 23;
|
---|
35 | }
|
---|
36 |
|
---|
37 | /* x mod y */
|
---|
38 | for (; ex > ey; ex--) {
|
---|
39 | i = uxi - uy.i;
|
---|
40 | if (i >> 31 == 0) {
|
---|
41 | if (i == 0)
|
---|
42 | return 0*x;
|
---|
43 | uxi = i;
|
---|
44 | }
|
---|
45 | uxi <<= 1;
|
---|
46 | }
|
---|
47 | i = uxi - uy.i;
|
---|
48 | if (i >> 31 == 0) {
|
---|
49 | if (i == 0)
|
---|
50 | return 0*x;
|
---|
51 | uxi = i;
|
---|
52 | }
|
---|
53 | for (; uxi>>23 == 0; uxi <<= 1, ex--);
|
---|
54 |
|
---|
55 | /* scale result up */
|
---|
56 | if (ex > 0) {
|
---|
57 | uxi -= 1U << 23;
|
---|
58 | uxi |= (uint32_t)ex << 23;
|
---|
59 | } else {
|
---|
60 | uxi >>= -ex + 1;
|
---|
61 | }
|
---|
62 | uxi |= sx;
|
---|
63 | ux.i = uxi;
|
---|
64 | return ux.f;
|
---|
65 | }
|
---|
Note:
See
TracBrowser
for help on using the repository browser.