37 lines
599 B
C
37 lines
599 B
C
#include "libc/math/libm.h"
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#if FLT_EVAL_METHOD==0
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#define EPS FLT_EPSILON
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#elif 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 float_t toint = 1/EPS;
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float roundf(float x)
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{
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union {float f; uint32_t i;} u = {x};
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int e = u.i >> 23 & 0xff;
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float_t y;
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if (e >= 0x7f+23)
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return x;
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if (u.i >> 31)
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x = -x;
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if (e < 0x7f-1) {
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FORCE_EVAL(x + toint);
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return 0*u.f;
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}
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y = x + toint - toint - x;
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if (y > 0.5f)
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y = y + x - 1;
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else if (y <= -0.5f)
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y = y + x + 1;
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else
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y = y + x;
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if (u.i >> 31)
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y = -y;
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return y;
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}
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