minix/lib/libm/src/k_standard.c
Ben Gras 2fe8fb192f Full switch to clang/ELF. Drop ack. Simplify.
There is important information about booting non-ack images in
docs/UPDATING. ack/aout-format images can't be built any more, and
booting clang/ELF-format ones is a little different. Updating to the
new boot monitor is recommended.

Changes in this commit:

	. drop boot monitor -> allowing dropping ack support
	. facility to copy ELF boot files to /boot so that old boot monitor
	  can still boot fairly easily, see UPDATING
	. no more ack-format libraries -> single-case libraries
	. some cleanup of OBJECT_FMT, COMPILER_TYPE, etc cases
	. drop several ack toolchain commands, but not all support
	  commands (e.g. aal is gone but acksize is not yet).
	. a few libc files moved to netbsd libc dir
	. new /bin/date as minix date used code in libc/
	. test compile fix
	. harmonize includes
	. /usr/lib is no longer special: without ack, /usr/lib plays no
	  kind of special bootstrapping role any more and bootstrapping
	  is done exclusively through packages, so releases depend even
	  less on the state of the machine making them now.
	. rename nbsd_lib* to lib*
	. reduce mtree
2012-02-14 14:52:02 +01:00

815 lines
21 KiB
C

/* @(#)k_standard.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.
* ====================================================
*/
#include <sys/cdefs.h>
#if defined(LIBM_SCCS) && !defined(lint)
__RCSID("$NetBSD: k_standard.c,v 1.16 2010/09/01 10:44:28 drochner Exp $");
#endif
#include "math.h"
#include "math_private.h"
#include <errno.h>
#ifndef _USE_WRITE
#include <stdio.h> /* fputs(), stderr */
#define WRITE2(u,v) fputs(u, stderr)
#else /* !defined(_USE_WRITE) */
#include <unistd.h> /* write */
#define WRITE2(u,v) write(2, u, v)
#undef fflush
#endif /* !defined(_USE_WRITE) */
static const double zero = 0.0; /* used as const */
/*
* Standard conformance (non-IEEE) on exception cases.
* Mapping:
* 1 -- acos(|x|>1)
* 2 -- asin(|x|>1)
* 3 -- atan2(+-0,+-0)
* 4 -- hypot overflow
* 5 -- cosh overflow
* 6 -- exp overflow
* 7 -- exp underflow
* 8 -- y0(0)
* 9 -- y0(-ve)
* 10-- y1(0)
* 11-- y1(-ve)
* 12-- yn(0)
* 13-- yn(-ve)
* 14-- lgamma(finite) overflow
* 15-- lgamma(-integer)
* 16-- log(0)
* 17-- log(x<0)
* 18-- log10(0)
* 19-- log10(x<0)
* 20-- pow(0.0,0.0)
* 21-- pow(x,y) overflow
* 22-- pow(x,y) underflow
* 23-- pow(0,negative)
* 24-- pow(neg,non-integral)
* 25-- sinh(finite) overflow
* 26-- sqrt(negative)
* 27-- fmod(x,0)
* 28-- remainder(x,0)
* 29-- acosh(x<1)
* 30-- atanh(|x|>1)
* 31-- atanh(|x|=1)
* 32-- scalb overflow
* 33-- scalb underflow
* 34-- j0(|x|>X_TLOSS)
* 35-- y0(x>X_TLOSS)
* 36-- j1(|x|>X_TLOSS)
* 37-- y1(x>X_TLOSS)
* 38-- jn(|x|>X_TLOSS, n)
* 39-- yn(x>X_TLOSS, n)
* 40-- gamma(finite) overflow
* 41-- gamma(-integer)
* 42-- pow(NaN,0.0)
* 48-- log2(0)
* 49-- log2(x<0)
*/
double
__kernel_standard(double x, double y, int type)
{
struct exception exc;
#ifndef HUGE_VAL /* this is the only routine that uses HUGE_VAL */
#define HUGE_VAL inf
double inf = 0.0;
SET_HIGH_WORD(inf,0x7ff00000); /* set inf to infinite */
#endif
#ifdef _USE_WRITE
(void) fflush(stdout);
#endif
exc.arg1 = x;
exc.arg2 = y;
switch(type) {
case 1:
case 101:
/* acos(|x|>1) */
exc.type = DOMAIN;
exc.name = type < 100 ? "acos" : "acosf";
exc.retval = zero;
if (_LIB_VERSION == _POSIX_) {
exc.retval = zero/zero;
errno = EDOM;
} else if (!matherr(&exc)) {
if(_LIB_VERSION == _SVID_) {
(void) WRITE2("acos: DOMAIN error\n", 19);
}
errno = EDOM;
}
break;
case 2:
case 102:
/* asin(|x|>1) */
exc.type = DOMAIN;
exc.name = type < 100 ? "asin" : "asinf";
exc.retval = zero;
if(_LIB_VERSION == _POSIX_) {
exc.retval = zero/zero;
errno = EDOM;
} else if (!matherr(&exc)) {
if(_LIB_VERSION == _SVID_) {
(void) WRITE2("asin: DOMAIN error\n", 19);
}
errno = EDOM;
}
break;
case 3:
case 103:
/* atan2(+-0,+-0) */
exc.arg1 = y;
exc.arg2 = x;
exc.type = DOMAIN;
exc.name = type < 100 ? "atan2" : "atan2f";
exc.retval = zero;
if(_LIB_VERSION == _POSIX_) {
exc.retval = copysign(signbit(y) ? M_PI : zero, x);
} else if (!matherr(&exc)) {
if(_LIB_VERSION == _SVID_) {
(void) WRITE2("atan2: DOMAIN error\n", 20);
}
errno = EDOM;
}
break;
case 4:
case 104:
/* hypot(finite,finite) overflow */
exc.type = OVERFLOW;
exc.name = type < 100 ? "hypot" : "hypotf";
if (_LIB_VERSION == _SVID_)
exc.retval = HUGE;
else
exc.retval = HUGE_VAL;
if (_LIB_VERSION == _POSIX_)
errno = ERANGE;
else if (!matherr(&exc)) {
errno = ERANGE;
}
break;
case 5:
case 105:
/* cosh(finite) overflow */
exc.type = OVERFLOW;
exc.name = type < 100 ? "cosh" : "coshf";
if (_LIB_VERSION == _SVID_)
exc.retval = HUGE;
else
exc.retval = HUGE_VAL;
if (_LIB_VERSION == _POSIX_)
errno = ERANGE;
else if (!matherr(&exc)) {
errno = ERANGE;
}
break;
case 6:
case 106:
/* exp(finite) overflow */
exc.type = OVERFLOW;
exc.name = type < 100 ? "exp" : "expf";
if (_LIB_VERSION == _SVID_)
exc.retval = HUGE;
else
exc.retval = HUGE_VAL;
if (_LIB_VERSION == _POSIX_)
errno = ERANGE;
else if (!matherr(&exc)) {
errno = ERANGE;
}
break;
case 7:
case 107:
/* exp(finite) underflow */
exc.type = UNDERFLOW;
exc.name = type < 100 ? "exp" : "expf";
exc.retval = zero;
if (_LIB_VERSION == _POSIX_)
errno = ERANGE;
else if (!matherr(&exc)) {
errno = ERANGE;
}
break;
case 8:
case 108:
/* y0(0) = -inf */
exc.type = DOMAIN; /* should be SING for IEEE */
exc.name = type < 100 ? "y0" : "y0f";
if (_LIB_VERSION == _SVID_)
exc.retval = -HUGE;
else
exc.retval = -HUGE_VAL;
if (_LIB_VERSION == _POSIX_)
errno = EDOM;
else if (!matherr(&exc)) {
if (_LIB_VERSION == _SVID_) {
(void) WRITE2("y0: DOMAIN error\n", 17);
}
errno = EDOM;
}
break;
case 9:
case 109:
/* y0(x<0) = NaN */
exc.type = DOMAIN;
exc.name = type < 100 ? "y0" : "y0f";
if (_LIB_VERSION == _SVID_)
exc.retval = -HUGE;
else
exc.retval = -HUGE_VAL;
if (_LIB_VERSION == _POSIX_)
errno = EDOM;
else if (!matherr(&exc)) {
if (_LIB_VERSION == _SVID_) {
(void) WRITE2("y0: DOMAIN error\n", 17);
}
errno = EDOM;
}
break;
case 10:
case 110:
/* y1(0) = -inf */
exc.type = DOMAIN; /* should be SING for IEEE */
exc.name = type < 100 ? "y1" : "y1f";
if (_LIB_VERSION == _SVID_)
exc.retval = -HUGE;
else
exc.retval = -HUGE_VAL;
if (_LIB_VERSION == _POSIX_)
errno = EDOM;
else if (!matherr(&exc)) {
if (_LIB_VERSION == _SVID_) {
(void) WRITE2("y1: DOMAIN error\n", 17);
}
errno = EDOM;
}
break;
case 11:
case 111:
/* y1(x<0) = NaN */
exc.type = DOMAIN;
exc.name = type < 100 ? "y1" : "y1f";
if (_LIB_VERSION == _SVID_)
exc.retval = -HUGE;
else
exc.retval = -HUGE_VAL;
if (_LIB_VERSION == _POSIX_)
errno = EDOM;
else if (!matherr(&exc)) {
if (_LIB_VERSION == _SVID_) {
(void) WRITE2("y1: DOMAIN error\n", 17);
}
errno = EDOM;
}
break;
case 12:
case 112:
/* yn(n,0) = -inf */
exc.type = DOMAIN; /* should be SING for IEEE */
exc.name = type < 100 ? "yn" : "ynf";
if (_LIB_VERSION == _SVID_)
exc.retval = -HUGE;
else
exc.retval = -HUGE_VAL;
if (_LIB_VERSION == _POSIX_)
errno = EDOM;
else if (!matherr(&exc)) {
if (_LIB_VERSION == _SVID_) {
(void) WRITE2("yn: DOMAIN error\n", 17);
}
errno = EDOM;
}
break;
case 13:
case 113:
/* yn(x<0) = NaN */
exc.type = DOMAIN;
exc.name = type < 100 ? "yn" : "ynf";
if (_LIB_VERSION == _SVID_)
exc.retval = -HUGE;
else
exc.retval = -HUGE_VAL;
if (_LIB_VERSION == _POSIX_)
errno = EDOM;
else if (!matherr(&exc)) {
if (_LIB_VERSION == _SVID_) {
(void) WRITE2("yn: DOMAIN error\n", 17);
}
errno = EDOM;
}
break;
case 14:
case 114:
/* lgamma(finite) overflow */
exc.type = OVERFLOW;
exc.name = type < 100 ? "lgamma" : "lgammaf";
if (_LIB_VERSION == _SVID_)
exc.retval = HUGE;
else
exc.retval = HUGE_VAL;
if (_LIB_VERSION == _POSIX_)
errno = ERANGE;
else if (!matherr(&exc)) {
errno = ERANGE;
}
break;
case 15:
case 115:
/* lgamma(-integer) or lgamma(0) */
exc.type = SING;
exc.name = type < 100 ? "lgamma" : "lgammaf";
if (_LIB_VERSION == _SVID_)
exc.retval = HUGE;
else
exc.retval = HUGE_VAL;
if (_LIB_VERSION == _POSIX_)
errno = EDOM;
else if (!matherr(&exc)) {
if (_LIB_VERSION == _SVID_) {
(void) WRITE2("lgamma: SING error\n", 19);
}
errno = EDOM;
}
break;
case 16:
case 116:
/* log(0) */
exc.type = SING;
exc.name = type < 100 ? "log" : "logf";
if (_LIB_VERSION == _SVID_)
exc.retval = -HUGE;
else
exc.retval = -HUGE_VAL;
if (_LIB_VERSION == _POSIX_)
errno = ERANGE;
else if (!matherr(&exc)) {
if (_LIB_VERSION == _SVID_) {
(void) WRITE2("log: SING error\n", 16);
}
errno = EDOM;
}
break;
case 17:
case 117:
/* log(x<0) */
exc.type = DOMAIN;
exc.name = type < 100 ? "log" : "logf";
if (_LIB_VERSION == _SVID_)
exc.retval = -HUGE;
else
exc.retval = -HUGE_VAL;
if (_LIB_VERSION == _POSIX_)
errno = EDOM;
else if (!matherr(&exc)) {
if (_LIB_VERSION == _SVID_) {
(void) WRITE2("log: DOMAIN error\n", 18);
}
errno = EDOM;
}
break;
case 18:
case 118:
/* log10(0) */
exc.type = SING;
exc.name = type < 100 ? "log10" : "log10f";
if (_LIB_VERSION == _SVID_)
exc.retval = -HUGE;
else
exc.retval = -HUGE_VAL;
if (_LIB_VERSION == _POSIX_)
errno = ERANGE;
else if (!matherr(&exc)) {
if (_LIB_VERSION == _SVID_) {
(void) WRITE2("log10: SING error\n", 18);
}
errno = EDOM;
}
break;
case 19:
case 119:
/* log10(x<0) */
exc.type = DOMAIN;
exc.name = type < 100 ? "log10" : "log10f";
if (_LIB_VERSION == _SVID_)
exc.retval = -HUGE;
else
exc.retval = -HUGE_VAL;
if (_LIB_VERSION == _POSIX_)
errno = EDOM;
else if (!matherr(&exc)) {
if (_LIB_VERSION == _SVID_) {
(void) WRITE2("log10: DOMAIN error\n", 20);
}
errno = EDOM;
}
break;
case 20:
case 120:
/* pow(0.0,0.0) */
/* error only if _LIB_VERSION == _SVID_ */
exc.type = DOMAIN;
exc.name = type < 100 ? "pow" : "powf";
exc.retval = zero;
if (_LIB_VERSION != _SVID_) exc.retval = 1.0;
else if (!matherr(&exc)) {
(void) WRITE2("pow(0,0): DOMAIN error\n", 23);
errno = EDOM;
}
break;
case 21:
case 121:
/* pow(x,y) overflow */
exc.type = OVERFLOW;
exc.name = type < 100 ? "pow" : "powf";
if (_LIB_VERSION == _SVID_) {
exc.retval = HUGE;
y *= 0.5;
if(x<zero&&rint(y)!=y) exc.retval = -HUGE;
} else {
exc.retval = HUGE_VAL;
y *= 0.5;
if(x<zero&&rint(y)!=y) exc.retval = -HUGE_VAL;
}
if (_LIB_VERSION == _POSIX_)
errno = ERANGE;
else if (!matherr(&exc)) {
errno = ERANGE;
}
break;
case 22:
case 122:
/* pow(x,y) underflow */
exc.type = UNDERFLOW;
exc.name = type < 100 ? "pow" : "powf";
exc.retval = zero;
if (_LIB_VERSION == _POSIX_)
errno = ERANGE;
else if (!matherr(&exc)) {
errno = ERANGE;
}
break;
case 23:
case 123:
/* 0**neg */
exc.type = DOMAIN;
exc.name = type < 100 ? "pow" : "powf";
if (_LIB_VERSION == _SVID_)
exc.retval = zero;
else
exc.retval = -HUGE_VAL;
if (_LIB_VERSION == _POSIX_)
errno = EDOM;
else if (!matherr(&exc)) {
if (_LIB_VERSION == _SVID_) {
(void) WRITE2("pow(0,neg): DOMAIN error\n", 25);
}
errno = EDOM;
}
break;
case 24:
case 124:
/* neg**non-integral */
exc.type = DOMAIN;
exc.name = type < 100 ? "pow" : "powf";
if (_LIB_VERSION == _SVID_)
exc.retval = zero;
else
exc.retval = zero/zero; /* X/Open allow NaN */
if (_LIB_VERSION == _POSIX_)
errno = EDOM;
else if (!matherr(&exc)) {
if (_LIB_VERSION == _SVID_) {
(void) WRITE2("neg**non-integral: DOMAIN error\n", 32);
}
errno = EDOM;
}
break;
case 25:
case 125:
/* sinh(finite) overflow */
exc.type = OVERFLOW;
exc.name = type < 100 ? "sinh" : "sinhf";
if (_LIB_VERSION == _SVID_)
exc.retval = ( (x>zero) ? HUGE : -HUGE);
else
exc.retval = ( (x>zero) ? HUGE_VAL : -HUGE_VAL);
if (_LIB_VERSION == _POSIX_)
errno = ERANGE;
else if (!matherr(&exc)) {
errno = ERANGE;
}
break;
case 26:
case 126:
/* sqrt(x<0) */
exc.type = DOMAIN;
exc.name = type < 100 ? "sqrt" : "sqrtf";
if (_LIB_VERSION == _SVID_)
exc.retval = zero;
else
exc.retval = zero/zero;
if (_LIB_VERSION == _POSIX_)
errno = EDOM;
else if (!matherr(&exc)) {
if (_LIB_VERSION == _SVID_) {
(void) WRITE2("sqrt: DOMAIN error\n", 19);
}
errno = EDOM;
}
break;
case 27:
case 127:
/* fmod(x,0) */
exc.type = DOMAIN;
exc.name = type < 100 ? "fmod" : "fmodf";
if (_LIB_VERSION == _SVID_)
exc.retval = x;
else
exc.retval = zero/zero;
if (_LIB_VERSION == _POSIX_)
errno = EDOM;
else if (!matherr(&exc)) {
if (_LIB_VERSION == _SVID_) {
(void) WRITE2("fmod: DOMAIN error\n", 20);
}
errno = EDOM;
}
break;
case 28:
case 128:
/* remainder(x,0) */
exc.type = DOMAIN;
exc.name = type < 100 ? "remainder" : "remainderf";
exc.retval = zero/zero;
if (_LIB_VERSION == _POSIX_)
errno = EDOM;
else if (!matherr(&exc)) {
if (_LIB_VERSION == _SVID_) {
(void) WRITE2("remainder: DOMAIN error\n", 24);
}
errno = EDOM;
}
break;
case 29:
case 129:
/* acosh(x<1) */
exc.type = DOMAIN;
exc.name = type < 100 ? "acosh" : "acoshf";
exc.retval = zero/zero;
if (_LIB_VERSION == _POSIX_)
errno = EDOM;
else if (!matherr(&exc)) {
if (_LIB_VERSION == _SVID_) {
(void) WRITE2("acosh: DOMAIN error\n", 20);
}
errno = EDOM;
}
break;
case 30:
case 130:
/* atanh(|x|>1) */
exc.type = DOMAIN;
exc.name = type < 100 ? "atanh" : "atanhf";
exc.retval = zero/zero;
if (_LIB_VERSION == _POSIX_)
errno = EDOM;
else if (!matherr(&exc)) {
if (_LIB_VERSION == _SVID_) {
(void) WRITE2("atanh: DOMAIN error\n", 20);
}
errno = EDOM;
}
break;
case 31:
case 131:
/* atanh(|x|=1) */
exc.type = SING;
exc.name = type < 100 ? "atanh" : "atanhf";
exc.retval = x/zero; /* sign(x)*inf */
if (_LIB_VERSION == _POSIX_)
errno = EDOM;
else if (!matherr(&exc)) {
if (_LIB_VERSION == _SVID_) {
(void) WRITE2("atanh: SING error\n", 18);
}
errno = EDOM;
}
break;
case 32:
case 132:
/* scalb overflow; SVID also returns +-HUGE_VAL */
exc.type = OVERFLOW;
exc.name = type < 100 ? "scalb" : "scalbf";
exc.retval = x > zero ? HUGE_VAL : -HUGE_VAL;
if (_LIB_VERSION == _POSIX_)
errno = ERANGE;
else if (!matherr(&exc)) {
errno = ERANGE;
}
break;
case 33:
case 133:
/* scalb underflow */
exc.type = UNDERFLOW;
exc.name = type < 100 ? "scalb" : "scalbf";
exc.retval = copysign(zero,x);
if (_LIB_VERSION == _POSIX_)
errno = ERANGE;
else if (!matherr(&exc)) {
errno = ERANGE;
}
break;
case 34:
case 134:
/* j0(|x|>X_TLOSS) */
exc.type = TLOSS;
exc.name = type < 100 ? "j0" : "j0f";
exc.retval = zero;
if (_LIB_VERSION == _POSIX_)
errno = ERANGE;
else if (!matherr(&exc)) {
if (_LIB_VERSION == _SVID_) {
(void) WRITE2(exc.name, 2);
(void) WRITE2(": TLOSS error\n", 14);
}
errno = ERANGE;
}
break;
case 35:
case 135:
/* y0(x>X_TLOSS) */
exc.type = TLOSS;
exc.name = type < 100 ? "y0" : "y0f";
exc.retval = zero;
if (_LIB_VERSION == _POSIX_)
errno = ERANGE;
else if (!matherr(&exc)) {
if (_LIB_VERSION == _SVID_) {
(void) WRITE2(exc.name, 2);
(void) WRITE2(": TLOSS error\n", 14);
}
errno = ERANGE;
}
break;
case 36:
case 136:
/* j1(|x|>X_TLOSS) */
exc.type = TLOSS;
exc.name = type < 100 ? "j1" : "j1f";
exc.retval = zero;
if (_LIB_VERSION == _POSIX_)
errno = ERANGE;
else if (!matherr(&exc)) {
if (_LIB_VERSION == _SVID_) {
(void) WRITE2(exc.name, 2);
(void) WRITE2(": TLOSS error\n", 14);
}
errno = ERANGE;
}
break;
case 37:
case 137:
/* y1(x>X_TLOSS) */
exc.type = TLOSS;
exc.name = type < 100 ? "y1" : "y1f";
exc.retval = zero;
if (_LIB_VERSION == _POSIX_)
errno = ERANGE;
else if (!matherr(&exc)) {
if (_LIB_VERSION == _SVID_) {
(void) WRITE2(exc.name, 2);
(void) WRITE2(": TLOSS error\n", 14);
}
errno = ERANGE;
}
break;
case 38:
case 138:
/* jn(|x|>X_TLOSS) */
exc.type = TLOSS;
exc.name = type < 100 ? "jn" : "jnf";
exc.retval = zero;
if (_LIB_VERSION == _POSIX_)
errno = ERANGE;
else if (!matherr(&exc)) {
if (_LIB_VERSION == _SVID_) {
(void) WRITE2(exc.name, 2);
(void) WRITE2(": TLOSS error\n", 14);
}
errno = ERANGE;
}
break;
case 39:
case 139:
/* yn(x>X_TLOSS) */
exc.type = TLOSS;
exc.name = type < 100 ? "yn" : "ynf";
exc.retval = zero;
if (_LIB_VERSION == _POSIX_)
errno = ERANGE;
else if (!matherr(&exc)) {
if (_LIB_VERSION == _SVID_) {
(void) WRITE2(exc.name, 2);
(void) WRITE2(": TLOSS error\n", 14);
}
errno = ERANGE;
}
break;
case 40:
case 140:
/* gamma(finite) overflow */
exc.type = OVERFLOW;
exc.name = type < 100 ? "gamma" : "gammaf";
if (_LIB_VERSION == _SVID_)
exc.retval = HUGE;
else
exc.retval = HUGE_VAL;
if (_LIB_VERSION == _POSIX_)
errno = ERANGE;
else if (!matherr(&exc)) {
errno = ERANGE;
}
break;
case 41:
case 141:
/* gamma(-integer) or gamma(0) */
exc.type = SING;
exc.name = type < 100 ? "gamma" : "gammaf";
if (_LIB_VERSION == _SVID_)
exc.retval = HUGE;
else
exc.retval = HUGE_VAL;
if (_LIB_VERSION == _POSIX_)
errno = EDOM;
else if (!matherr(&exc)) {
if (_LIB_VERSION == _SVID_) {
(void) WRITE2("gamma: SING error\n", 18);
}
errno = EDOM;
}
break;
case 42:
case 142:
/* pow(NaN,0.0) */
/* error only if _LIB_VERSION == _SVID_ & _XOPEN_ */
exc.type = DOMAIN;
exc.name = type < 100 ? "pow" : "powf";
exc.retval = x;
if (_LIB_VERSION == _IEEE_ ||
_LIB_VERSION == _POSIX_) exc.retval = 1.0;
else if (!matherr(&exc)) {
errno = EDOM;
}
break;
case 48:
case 148:
/* log2(0) */
exc.type = SING;
exc.name = type < 100 ? "log2" : "log2f";
if (_LIB_VERSION == _SVID_)
exc.retval = -HUGE;
else
exc.retval = -HUGE_VAL;
if (_LIB_VERSION == _POSIX_)
errno = ERANGE;
else if (!matherr(&exc)) {
if (_LIB_VERSION == _SVID_) {
(void) WRITE2("log2: SING error\n", 18);
}
errno = EDOM;
}
break;
case 49:
case 149:
/* log2(x<0) */
exc.type = DOMAIN;
exc.name = type < 100 ? "log2" : "log2f";
if (_LIB_VERSION == _SVID_)
exc.retval = -HUGE;
else
exc.retval = -HUGE_VAL;
if (_LIB_VERSION == _POSIX_)
errno = EDOM;
else if (!matherr(&exc)) {
if (_LIB_VERSION == _SVID_) {
(void) WRITE2("log2: DOMAIN error\n", 20);
}
errno = EDOM;
}
break;
}
return exc.retval;
}