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Updated math code from the uClibc 0.9.33 release

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This commit is contained in:
Sam Lantinga
2017-11-04 15:53:19 -07:00
parent 34502143d9
commit 6cf065753c
18 changed files with 945 additions and 1198 deletions
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110
src/libm/s_scalbn.c
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@@ -1,4 +1,3 @@
/* @(#)s_scalbn.c 5.1 93/09/24 */
/*
* ====================================================
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
@@ -10,70 +9,69 @@
* ====================================================
*/
#if defined(LIBM_SCCS) && !defined(lint)
static const char rcsid[] =
"$NetBSD: s_scalbn.c,v 1.8 1995/05/10 20:48:08 jtc Exp $";
#endif
/*
* scalbn (double x, int n)
* scalbn(x,n) returns x* 2**n computed by exponent
* scalbln(double x, long n)
* scalbln(x,n) returns x * 2**n computed by exponent
* manipulation rather than by actually performing an
* exponentiation or a multiplication.
*/
#include "math_libm.h"
#include "math_private.h"
#include <limits.h>
libm_hidden_proto(copysign)
#ifdef __STDC__
static const double
#else
static double
#endif
two54 = 1.80143985094819840000e+16, /* 0x43500000, 0x00000000 */
twom54 = 5.55111512312578270212e-17, /* 0x3C900000, 0x00000000 */
huge_val = 1.0e+300, tiny = 1.0e-300;
static const double
two54 = 1.80143985094819840000e+16, /* 0x43500000, 0x00000000 */
twom54 = 5.55111512312578270212e-17, /* 0x3C900000, 0x00000000 */
huge = 1.0e+300,
tiny = 1.0e-300;
libm_hidden_proto(scalbn)
#ifdef __STDC__
double scalbn(double x, int n)
#else
double scalbn(x, n)
double x;
int n;
#endif
double scalbln(double x, long n)
{
int32_t k, hx, lx;
EXTRACT_WORDS(hx, lx, x);
k = (hx & 0x7ff00000) >> 20; /* extract exponent */
if (k == 0) { /* 0 or subnormal x */
if ((lx | (hx & 0x7fffffff)) == 0)
return x; /* +-0 */
x *= two54;
GET_HIGH_WORD(hx, x);
k = ((hx & 0x7ff00000) >> 20) - 54;
if (n < -50000)
return tiny * x; /* underflow */
}
if (k == 0x7ff)
return x + x; /* NaN or Inf */
k = k + n;
if (k > 0x7fe)
return huge_val * copysign(huge_val, x); /* overflow */
if (k > 0) { /* normal result */
SET_HIGH_WORD(x, (hx & 0x800fffff) | (k << 20));
return x;
}
if (k <= -54) {
if (n > 50000) /* in case integer overflow in n+k */
return huge_val * copysign(huge_val, x); /* overflow */
else
return tiny * copysign(tiny, x); /* underflow */
}
k += 54; /* subnormal result */
SET_HIGH_WORD(x, (hx & 0x800fffff) | (k << 20));
return x * twom54;
}
int32_t k, hx, lx;
EXTRACT_WORDS(hx, lx, x);
k = (hx & 0x7ff00000) >> 20; /* extract exponent */
if (k == 0) { /* 0 or subnormal x */
if ((lx | (hx & 0x7fffffff)) == 0)
return x; /* +-0 */
x *= two54;
GET_HIGH_WORD(hx, x);
k = ((hx & 0x7ff00000) >> 20) - 54;
}
if (k == 0x7ff)
return x + x; /* NaN or Inf */
k = k + n;
if (k > 0x7fe)
return huge * copysign(huge, x); /* overflow */
if (n < -50000)
return tiny * copysign(tiny, x); /* underflow */
if (k > 0) { /* normal result */
SET_HIGH_WORD(x, (hx & 0x800fffff) | (k << 20));
return x;
}
if (k <= -54) {
if (n > 50000) /* in case integer overflow in n+k */
return huge * copysign(huge, x); /* overflow */
return tiny * copysign(tiny, x); /* underflow */
}
k += 54; /* subnormal result */
SET_HIGH_WORD(x, (hx & 0x800fffff) | (k << 20));
return x * twom54;
}
libm_hidden_def(scalbln)
#if LONG_MAX == INT_MAX
/* strong_alias(scalbln, scalbn) - "error: conflicting types for 'scalbn'"
* because it tries to declare "typeof(scalbln) scalbn;"
* which tries to give "long" parameter to scalbn.
* Doing it by hand:
*/
__typeof(scalbn) scalbn __attribute__((alias("scalbln")));
#else
double scalbn(double x, int n)
{
return scalbln(x, n);
}
#endif
libm_hidden_def(scalbn)