SDL/src/libm/s_floor.c
David Ludwig 70438be272 WinRT: fixed bug whereby SDL would override an app's default orientation
WinRT apps can set a default, preferred orientation via a .appxmanifest file.
SDL was overriding this on app startup, and making the app use all possible
orientations (landscape and portrait).

Thanks to Eric Wing for the heads up on this!
2014-12-03 10:55:23 -05:00

97 lines
2.6 KiB
C

/* @(#)s_floor.c 5.1 93/09/24 */
/*
* ====================================================
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
*
* Developed at SunPro, a Sun Microsystems, Inc. business.
* Permission to use, copy, modify, and distribute this
* software is freely granted, provided that this notice
* is preserved.
* ====================================================
*/
#if defined(LIBM_SCCS) && !defined(lint)
static const char rcsid[] =
"$NetBSD: s_floor.c,v 1.8 1995/05/10 20:47:20 jtc Exp $";
#endif
/*
* floor(x)
* Return x rounded toward -inf to integral value
* Method:
* Bit twiddling.
* Exception:
* Inexact flag raised if x not equal to floor(x).
*/
#include "math_libm.h"
#include "math_private.h"
#ifdef __STDC__
static const double huge_val = 1.0e300;
#else
static double huge_val = 1.0e300;
#endif
libm_hidden_proto(floor)
#ifdef __STDC__
double floor(double x)
#else
double floor(x)
double x;
#endif
{
int32_t i0, i1, j0;
u_int32_t i, j;
EXTRACT_WORDS(i0, i1, x);
j0 = ((i0 >> 20) & 0x7ff) - 0x3ff;
if (j0 < 20) {
if (j0 < 0) { /* raise inexact if x != 0 */
if (huge_val + x > 0.0) { /* return 0*sign(x) if |x|<1 */
if (i0 >= 0) {
i0 = i1 = 0;
} else if (((i0 & 0x7fffffff) | i1) != 0) {
i0 = 0xbff00000;
i1 = 0;
}
}
} else {
i = (0x000fffff) >> j0;
if (((i0 & i) | i1) == 0)
return x; /* x is integral */
if (huge_val + x > 0.0) { /* raise inexact flag */
if (i0 < 0)
i0 += (0x00100000) >> j0;
i0 &= (~i);
i1 = 0;
}
}
} else if (j0 > 51) {
if (j0 == 0x400)
return x + x; /* inf or NaN */
else
return x; /* x is integral */
} else {
i = ((u_int32_t) (0xffffffff)) >> (j0 - 20);
if ((i1 & i) == 0)
return x; /* x is integral */
if (huge_val + x > 0.0) { /* raise inexact flag */
if (i0 < 0) {
if (j0 == 20)
i0 += 1;
else {
j = i1 + (1 << (52 - j0));
if (j < (u_int32_t) i1)
i0 += 1; /* got a carry */
i1 = j;
}
}
i1 &= (~i);
}
}
INSERT_WORDS(x, i0, i1);
return x;
}
libm_hidden_def(floor)