Mercurial > sdl-ios-xcode
annotate src/libm/s_floor.c @ 3331:d44a0a913aa2
Eric Wing to Sam
Lots of fixes.
Fixed missing power management building.
Added template icons to the project templates.
DocSet stuff
Documentation fixes..
Fixed all the SDLtests. (Lots of tedious work.) It now depends on the static library target for convenience so I am not going to remove it from the SDL xcode project.
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Thu, 01 Oct 2009 15:30:26 +0000 |
| parents | dc1eb82ffdaa |
| children | 9ac6f0782dd6 |
| rev | line source |
|---|---|
| 2758 | 1 /* @(#)s_floor.c 5.1 93/09/24 */ |
| 2 /* | |
| 3 * ==================================================== | |
| 4 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. | |
| 5 * | |
| 6 * Developed at SunPro, a Sun Microsystems, Inc. business. | |
| 7 * Permission to use, copy, modify, and distribute this | |
| 8 * software is freely granted, provided that this notice | |
| 9 * is preserved. | |
| 10 * ==================================================== | |
| 11 */ | |
| 12 | |
| 13 #if defined(LIBM_SCCS) && !defined(lint) | |
| 3162 | 14 static const char rcsid[] = |
| 2758 | 15 "$NetBSD: s_floor.c,v 1.8 1995/05/10 20:47:20 jtc Exp $"; |
| 16 #endif | |
| 17 | |
| 18 /* | |
| 19 * floor(x) | |
| 20 * Return x rounded toward -inf to integral value | |
| 21 * Method: | |
| 22 * Bit twiddling. | |
| 23 * Exception: | |
| 24 * Inexact flag raised if x not equal to floor(x). | |
| 25 */ | |
| 26 | |
| 27 #include "math.h" | |
| 28 #include "math_private.h" | |
| 29 | |
| 30 #ifdef __STDC__ | |
| 31 static const double huge = 1.0e300; | |
| 32 #else | |
| 33 static double huge = 1.0e300; | |
| 34 #endif | |
| 35 | |
| 36 libm_hidden_proto(floor) | |
| 37 #ifdef __STDC__ | |
| 38 double floor(double x) | |
| 39 #else | |
| 40 double floor(x) | |
| 41 double x; | |
| 42 #endif | |
| 43 { | |
| 44 int32_t i0, i1, j0; | |
| 45 u_int32_t i, j; | |
| 46 EXTRACT_WORDS(i0, i1, x); | |
| 47 j0 = ((i0 >> 20) & 0x7ff) - 0x3ff; | |
| 48 if (j0 < 20) { | |
| 49 if (j0 < 0) { /* raise inexact if x != 0 */ | |
| 50 if (huge + x > 0.0) { /* return 0*sign(x) if |x|<1 */ | |
| 51 if (i0 >= 0) { | |
| 52 i0 = i1 = 0; | |
| 53 } else if (((i0 & 0x7fffffff) | i1) != 0) { | |
| 54 i0 = 0xbff00000; | |
| 55 i1 = 0; | |
| 56 } | |
| 57 } | |
| 58 } else { | |
| 59 i = (0x000fffff) >> j0; | |
| 60 if (((i0 & i) | i1) == 0) | |
| 61 return x; /* x is integral */ | |
| 62 if (huge + x > 0.0) { /* raise inexact flag */ | |
| 63 if (i0 < 0) | |
| 64 i0 += (0x00100000) >> j0; | |
| 65 i0 &= (~i); | |
| 66 i1 = 0; | |
| 67 } | |
| 68 } | |
| 69 } else if (j0 > 51) { | |
| 70 if (j0 == 0x400) | |
| 71 return x + x; /* inf or NaN */ | |
| 72 else | |
| 73 return x; /* x is integral */ | |
| 74 } else { | |
| 75 i = ((u_int32_t) (0xffffffff)) >> (j0 - 20); | |
| 76 if ((i1 & i) == 0) | |
| 77 return x; /* x is integral */ | |
| 78 if (huge + x > 0.0) { /* raise inexact flag */ | |
| 79 if (i0 < 0) { | |
| 80 if (j0 == 20) | |
| 81 i0 += 1; | |
| 82 else { | |
| 83 j = i1 + (1 << (52 - j0)); | |
|
2765
f55c87ae336b
Final merge of Google Summer of Code 2008 work...
Sam Lantinga <slouken@libsdl.org>
parents:
2760
diff
changeset
|
84 if (j < (u_int32_t) i1) |
| 2758 | 85 i0 += 1; /* got a carry */ |
| 86 i1 = j; | |
| 87 } | |
| 88 } | |
| 89 i1 &= (~i); | |
| 90 } | |
| 91 } | |
| 92 INSERT_WORDS(x, i0, i1); | |
| 93 return x; | |
| 94 } | |
| 95 | |
| 96 libm_hidden_def(floor) |