239c2bf93e
* libc/misc/unctrl.c: Replace FUNCTION description.
* libc/signal/signal.c: Remove documentation for raise and _raise_r.
* libc/stdio/getdelim.c: Fix spelling errors.
* libc/stdio/getw.c: Put RETURNS on a separate line. Fix punctuation.
* libc/stdio/putw.c: Likewise.
* libc/stdlib/a64l.c: Fix formatting, spelling and punctuation in
documentation.
* libc/stdlib/assert.c: Do not capitalize FUNCTION description.
* libc/stdlib/efgcvt.c: Add spaces to FUNCTION description.
* libc/stdlib/envlock.c: Use em-dash in FUNCTION description.
* libc/stdlib/mlock.c: Likewise.
* libc/stdlib/mstats.c: Likewise.
* libc/time/tzlock.c: Likewise.
* libc/stdlib/rand.c: Use "multi-threaded" and "thread-safe" in NOTES.
* libc/stdlib/rand48.c: Remove extra space in FUNCTION description
and hyphenate "pseudo-random".
* libc/string/bcmp.c: Remove extra blank lines in documentation.
* libc/string/strncat.c: Likewise.
* libc/string/memchr.c: Remove extra ">" character in documentation.
* libc/string/strcspn.c: Use "characters" instead of "chars".
* libc/string/strpbrk.c: Likewise.
* libc/string/strerror_r.c: Capitalize "GNU".
* libc/string/strnlen.c: Likewise.
* libc/string/strtok.c: Fix formatting, spelling and punctuation in
documentation. Use "multi-threaded" and "thread-safe" in NOTES.
* libc/string/wcscat.c: Split PORTABILITY into two paragraphs.
* libc/string/wcschr.c: Likewise.
* libc/string/wcscmp.c: Likewise.
* libc/string/wcscpy.c: Likewise.
* libc/string/wcscspn.c: Likewise.
* libc/string/wcslen.c: Likewise.
* libc/string/wcsncat.c: Likewise.
* libc/string/wcsncmp.c: Likewise.
* libc/string/wcsncpy.c: Likewise.
* libc/string/wcsnlen.c: Likewise.
* libc/string/wcspbrk.c: Likewise.
* libc/string/wcsrchr.c: Likewise.
* libc/string/wcsspn.c: Likewise.
* libc/string/wmemchr.c: Likewise.
* libc/string/wmemcmp.c: Likewise.
* libc/string/wmemcpy.c: Likewise.
* libc/string/wmemset.c: Likewise.
* libc/string/wmemmove.c: Likewise. Also fix FUNCTION description.
* libc/string/wcswidth.c: Formatting and punctuation in documentation.
* libc/string/wcwidth.c: Likewise.
* libm/common/s_modf.c: Remove extra period from documentation.
* libm/math/s_isnan.c: Fix formatting, grammar and punctuation in
documentation.
* libm/mathfp/s_isnan.c: Likewise.
* libm/math/s_ldexp.c: Fix punctuation.
* libm/mathfp/s_ldexp.c: Likewise.
* libm/math/w_log.c: Likewise.
* libm/mathfp/s_logarithm.c: Likewise.
* libm/math/w_j0.c: Add spaces to FUNCTION description.
* libm/mathfp/w_jn.c: Likewise.
126 lines
2.3 KiB
C
126 lines
2.3 KiB
C
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/* @(#)z_ldexp.c 1.0 98/08/13 */
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/*
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FUNCTION
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<<ldexp>>, <<ldexpf>>---load exponent
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INDEX
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ldexp
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INDEX
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ldexpf
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ANSI_SYNOPSIS
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#include <math.h>
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double ldexp(double <[val]>, int <[exp]>);
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float ldexpf(float <[val]>, int <[exp]>);
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TRAD_SYNOPSIS
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#include <math.h>
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double ldexp(<[val]>, <[exp]>)
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double <[val]>;
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int <[exp]>;
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float ldexpf(<[val]>, <[exp]>)
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float <[val]>;
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int <[exp]>;
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DESCRIPTION
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<<ldexp>> calculates the value
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@ifnottex
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<[val]> times 2 to the power <[exp]>.
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@end ifnottex
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@tex
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$val\times 2^{exp}$.
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@end tex
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<<ldexpf>> is identical, save that it takes and returns <<float>>
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rather than <<double>> values.
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RETURNS
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<<ldexp>> returns the calculated value.
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Underflow and overflow both set <<errno>> to <<ERANGE>>.
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On underflow, <<ldexp>> and <<ldexpf>> return 0.0.
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On overflow, <<ldexp>> returns plus or minus <<HUGE_VAL>>.
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PORTABILITY
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<<ldexp>> is ANSI. <<ldexpf>> is an extension.
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*/
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/******************************************************************
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* ldexp
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*
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* Input:
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* d - a floating point value
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* e - an exponent value
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*
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* Output:
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* A floating point value f such that f = d * 2 ^ e.
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*
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* Description:
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* This function creates a floating point number f such that
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* f = d * 2 ^ e.
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*
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*****************************************************************/
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#include <float.h>
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#include "fdlibm.h"
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#include "zmath.h"
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#ifndef _DOUBLE_IS_32BITS
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#define DOUBLE_EXP_OFFS 1023
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double
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_DEFUN (ldexp, (double, int),
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double d _AND
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int e)
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{
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int exp;
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__uint32_t hd;
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GET_HIGH_WORD (hd, d);
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/* Check for special values and then scale d by e. */
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switch (numtest (d))
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{
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case NAN:
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errno = EDOM;
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break;
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case INF:
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errno = ERANGE;
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break;
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case 0:
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break;
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default:
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exp = (hd & 0x7ff00000) >> 20;
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exp += e;
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if (exp > DBL_MAX_EXP + DOUBLE_EXP_OFFS)
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{
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errno = ERANGE;
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d = z_infinity.d;
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}
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else if (exp < DBL_MIN_EXP + DOUBLE_EXP_OFFS)
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{
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errno = ERANGE;
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d = -z_infinity.d;
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}
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else
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{
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hd &= 0x800fffff;
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hd |= exp << 20;
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SET_HIGH_WORD (d, hd);
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}
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}
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return (d);
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}
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#endif /* _DOUBLE_IS_32BITS */
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