The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 1 | /* s_rintf.c -- float version of s_rint.c. |
| 2 | * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. |
| 3 | */ |
| 4 | |
| 5 | /* |
| 6 | * ==================================================== |
| 7 | * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
| 8 | * |
| 9 | * Developed at SunPro, a Sun Microsystems, Inc. business. |
| 10 | * Permission to use, copy, modify, and distribute this |
| 11 | * software is freely granted, provided that this notice |
| 12 | * is preserved. |
| 13 | * ==================================================== |
| 14 | */ |
| 15 | |
Elliott Hughes | a0ee078 | 2013-01-30 19:06:37 -0800 | [diff] [blame] | 16 | #include <sys/cdefs.h> |
| 17 | __FBSDID("$FreeBSD$"); |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 18 | |
Elliott Hughes | a0ee078 | 2013-01-30 19:06:37 -0800 | [diff] [blame] | 19 | #include <float.h> |
| 20 | #include <stdint.h> |
| 21 | |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 22 | #include "math.h" |
| 23 | #include "math_private.h" |
| 24 | |
| 25 | static const float |
| 26 | TWO23[2]={ |
| 27 | 8.3886080000e+06, /* 0x4b000000 */ |
| 28 | -8.3886080000e+06, /* 0xcb000000 */ |
| 29 | }; |
| 30 | |
| 31 | float |
| 32 | rintf(float x) |
| 33 | { |
| 34 | int32_t i0,j0,sx; |
Elliott Hughes | a0ee078 | 2013-01-30 19:06:37 -0800 | [diff] [blame] | 35 | float w,t; |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 36 | GET_FLOAT_WORD(i0,x); |
| 37 | sx = (i0>>31)&1; |
| 38 | j0 = ((i0>>23)&0xff)-0x7f; |
| 39 | if(j0<23) { |
| 40 | if(j0<0) { |
| 41 | if((i0&0x7fffffff)==0) return x; |
Elliott Hughes | a0ee078 | 2013-01-30 19:06:37 -0800 | [diff] [blame] | 42 | STRICT_ASSIGN(float,w,TWO23[sx]+x); |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 43 | t = w-TWO23[sx]; |
| 44 | GET_FLOAT_WORD(i0,t); |
| 45 | SET_FLOAT_WORD(t,(i0&0x7fffffff)|(sx<<31)); |
| 46 | return t; |
| 47 | } |
Elliott Hughes | a0ee078 | 2013-01-30 19:06:37 -0800 | [diff] [blame] | 48 | STRICT_ASSIGN(float,w,TWO23[sx]+x); |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 49 | return w-TWO23[sx]; |
| 50 | } |
| 51 | if(j0==0x80) return x+x; /* inf or NaN */ |
| 52 | else return x; /* x is integral */ |
| 53 | } |