32 lines
533 B
C
32 lines
533 B
C
#include "libc/math/math.h"
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#include "libc/str/str.h"
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#if FLT_EVAL_METHOD == 0 || FLT_EVAL_METHOD == 1
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#define EPS DBL_EPSILON
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#elif FLT_EVAL_METHOD == 2
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#define EPS LDBL_EPSILON
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#endif
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static const double_t toint = 1 / EPS;
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double rint(double x) {
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int e, s;
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uint64_t i;
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double_t y;
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memcpy(&i, &x, 8);
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e = i >> 52 & 0x7ff;
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s = i >> 63;
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if (e >= 0x3ff + 52) {
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return x;
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}
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if (s) {
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y = x - toint + toint;
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} else {
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y = x + toint - toint;
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}
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if (y == 0) {
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return s ? -0.0 : 0;
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}
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return y;
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}
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