Akos Kiss
8dd5186a0d
* First re-style was done automatically by indent to minimize the
chance of errors during rewrite.
* Manual changes were applied to non-critical places only (comments
and spaces):
* Replaced all tabs with spaces.
* Fixed tab stops in formulae in function comments.
(Note: ASCII art for math formulae (especially for super- and
subscripts) is a terrible idea.)
* Unified the style of function comments.
* Moved some in-code comments to their right places, which indent
couldn't handle.
* Added spaces to formulae of in-code comments to make them more
readable.
* Added braces mandated by jerry style guidelines.
* Added parentheses to multiline #ifdef.
JerryScript-DCO-1.0-Signed-off-by: Akos Kiss akiss@inf.u-szeged.hu
116 lines
2.1 KiB
C
116 lines
2.1 KiB
C
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/* @(#)s_ceil.c 1.3 95/01/18 */
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/*
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunSoft, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*/
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/* ceil(x)
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* Return x rounded toward -inf to integral value
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*
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* Method:
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* Bit twiddling.
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*
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* Exception:
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* Inexact flag raised if x not equal to ceil(x).
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*/
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#include "fdlibm.h"
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#define huge 1.0e300
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double
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ceil (double x)
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{
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int i0, i1, j0;
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unsigned i, j;
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i0 = __HI (x);
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i1 = __LO (x);
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j0 = ((i0 >> 20) & 0x7ff) - 0x3ff;
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if (j0 < 20)
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{
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if (j0 < 0) /* raise inexact if x != 0 */
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{
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if (huge + x > 0.0) /* return 0 * sign(x) if |x| < 1 */
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{
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if (i0 < 0)
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{
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i0 = 0x80000000;
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i1 = 0;
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}
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else if ((i0 | i1) != 0)
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{
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i0 = 0x3ff00000;
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i1 = 0;
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}
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}
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}
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else
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{
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i = (0x000fffff) >> j0;
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if (((i0 & i) | i1) == 0) /* x is integral */
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{
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return x;
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}
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if (huge + x > 0.0) /* raise inexact flag */
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{
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if (i0 > 0)
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{
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i0 += (0x00100000) >> j0;
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}
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i0 &= (~i);
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i1 = 0;
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}
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}
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}
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else if (j0 > 51)
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{
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if (j0 == 0x400) /* inf or NaN */
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{
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return x + x;
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}
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else /* x is integral */
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{
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return x;
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}
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}
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else
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{
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i = ((unsigned) (0xffffffff)) >> (j0 - 20);
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if ((i1 & i) == 0) /* x is integral */
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{
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return x;
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}
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if (huge + x > 0.0) /* raise inexact flag */
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{
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if (i0 > 0)
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{
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if (j0 == 20)
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{
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i0 += 1;
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}
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else
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{
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j = i1 + (1 << (52 - j0));
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if (j < i1) /* got a carry */
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{
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i0 += 1;
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}
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i1 = j;
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}
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}
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i1 &= (~i);
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}
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}
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__HI (x) = i0;
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__LO (x) = i1;
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return x;
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} /* ceil */
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