67 lines
1.3 KiB
C
67 lines
1.3 KiB
C
#include <float.h>
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#include "math.h"
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#include "math_private.h"
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static const double huge = 1.0e300;
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double ceil(double x)
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{
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int32_t i0, i1, j0;
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u_int32_t i, j;
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EXTRACT_WORDS(i0, i1, x);
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j0 = ((i0 >> 20) & 0x7ff) - 0x3ff;
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if (j0 < 20) {
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if (j0 < 0) { /* raise inexact if x != 0 */
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if (huge + x > 0.0) { /* return 0*sign(x) if |x|<1 */
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if (i0 < 0) {
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i0 = 0x80000000;
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i1 = 0;
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} else if ((i0 | i1) != 0) {
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i0 = 0x3ff00000;
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i1 = 0;
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}
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}
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} else {
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i = (0x000fffff) >> j0;
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if (((i0 & i) | i1) == 0)
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return x; /* x is integral */
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if (huge + x > 0.0) { /* raise inexact flag */
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if (i0 > 0)
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i0 += (0x00100000) >> j0;
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i0 &= (~i);
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i1 = 0;
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}
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}
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} else if (j0 > 51) {
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if (j0 == 0x400)
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return x + x; /* inf or NaN */
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else
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return x; /* x is integral */
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} else {
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i = ((u_int32_t)(0xffffffff)) >> (j0 - 20);
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if ((i1 & i) == 0)
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return x; /* x is integral */
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if (huge + x > 0.0) { /* raise inexact flag */
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if (i0 > 0) {
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if (j0 == 20)
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i0 += 1;
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else {
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j = i1 + (1 << (52 - j0));
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if (j < i1)
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i0 += 1; /* got a carry */
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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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INSERT_WORDS(x, i0, i1);
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return x;
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}
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/*
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#if LDBL_MANT_DIG == 53
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openlibm_weak_reference(ceil, ceill);
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#endif
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*/
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