8e2ff164cc
Requested by b/3370708 to export these through RenderScript. Change-Id: I1ae69f87a1ad4765b2dee8e4a6f2f3a6eb7c5ad4
132 lines
3.6 KiB
C
132 lines
3.6 KiB
C
/*-
|
|
* Copyright (c) 2007 David Schultz
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*
|
|
* $FreeBSD$
|
|
*/
|
|
|
|
#include <sys/endian.h>
|
|
#include <ctype.h>
|
|
#include <float.h>
|
|
#include <math.h>
|
|
#include <stdint.h>
|
|
#include <strings.h>
|
|
|
|
#include "math_private.h"
|
|
|
|
/* digittoint is in the FreeBSD C library, but not Bionic at this point */
|
|
static int
|
|
digittoint(char ch)
|
|
{
|
|
int d;
|
|
|
|
d = ch - '0';
|
|
if ((unsigned)d < 10) {
|
|
return d;
|
|
}
|
|
d = ch - 'a';
|
|
if ((unsigned)d < 6) {
|
|
return d + 10;
|
|
}
|
|
d = ch - 'A';
|
|
if ((unsigned)d < 6) {
|
|
return d + 10;
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
/*
|
|
* Scan a string of hexadecimal digits (the format nan(3) expects) and
|
|
* make a bit array (using the local endianness). We stop when we
|
|
* encounter an invalid character, NUL, etc. If we overflow, we do
|
|
* the same as gcc's __builtin_nan(), namely, discard the high order bits.
|
|
*
|
|
* The format this routine accepts needs to be compatible with what is used
|
|
* in contrib/gdtoa/hexnan.c (for strtod/scanf) and what is used in
|
|
* __builtin_nan(). In fact, we're only 100% compatible for strings we
|
|
* consider valid, so we might be violating the C standard. But it's
|
|
* impossible to use nan(3) portably anyway, so this seems good enough.
|
|
*/
|
|
void
|
|
_scan_nan(uint32_t *words, int num_words, const char *s)
|
|
{
|
|
int si; /* index into s */
|
|
int bitpos; /* index into words (in bits) */
|
|
|
|
bzero(words, num_words * sizeof(uint32_t));
|
|
|
|
/* Allow a leading '0x'. (It's expected, but redundant.) */
|
|
if (s[0] == '0' && (s[1] == 'x' || s[1] == 'X'))
|
|
s += 2;
|
|
|
|
/* Scan forwards in the string, looking for the end of the sequence. */
|
|
for (si = 0; isxdigit(s[si]); si++)
|
|
;
|
|
|
|
/* Scan backwards, filling in the bits in words[] as we go. */
|
|
#if _BYTE_ORDER == _LITTLE_ENDIAN
|
|
for (bitpos = 0; bitpos < 32 * num_words; bitpos += 4) {
|
|
#else
|
|
for (bitpos = 32 * num_words - 4; bitpos >= 0; bitpos -= 4) {
|
|
#endif
|
|
if (--si < 0)
|
|
break;
|
|
words[bitpos / 32] |= digittoint(s[si]) << (bitpos % 32);
|
|
}
|
|
}
|
|
|
|
double
|
|
nan(const char *s)
|
|
{
|
|
union {
|
|
double d;
|
|
uint32_t bits[2];
|
|
} u;
|
|
|
|
_scan_nan(u.bits, 2, s);
|
|
#if _BYTE_ORDER == _LITTLE_ENDIAN
|
|
u.bits[1] |= 0x7ff80000;
|
|
#else
|
|
u.bits[0] |= 0x7ff80000;
|
|
#endif
|
|
return (u.d);
|
|
}
|
|
|
|
float
|
|
nanf(const char *s)
|
|
{
|
|
union {
|
|
float f;
|
|
uint32_t bits[1];
|
|
} u;
|
|
|
|
_scan_nan(u.bits, 1, s);
|
|
u.bits[0] |= 0x7fc00000;
|
|
return (u.f);
|
|
}
|
|
|
|
#if (LDBL_MANT_DIG == 53)
|
|
__weak_alias(nanl, nan);
|
|
#endif
|