Mercurial > sdl-ios-xcode
annotate src/libm/s_floor.c @ 2763:6fc50bdd88c0
Some cleanups on the new XInput code.
One or two things got moved around, but largely this is hooked up correctly
in the Unix configure system now: it can be dynamically loaded and fallback
gracefully if not available, or libXi can be directly linked to libSDL.
XInput support can be --disable'd from the configure script, too (defaults to
enabled).
Please note that while the framework is in place to gracefully fallback, the
current state of the source requires XInput. We'll need to adjust a few
things still to correct this.
| author | Ryan C. Gordon <icculus@icculus.org> |
|---|---|
| date | Wed, 17 Sep 2008 08:20:57 +0000 |
| parents | 02aa80d7905f |
| children | f55c87ae336b |
| 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) | |
| 14 static char rcsid[] = | |
| 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)); | |
|
2760
02aa80d7905f
Updated Visual C++ build
Sam Lantinga <slouken@libsdl.org>
parents:
2758
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) |