31 lines
650 B
C
31 lines
650 B
C
#include "libc/math/libm.h"
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float nextafterf(float x, float y)
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{
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union {float f; uint32_t i;} ux={x}, uy={y};
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uint32_t ax, ay, e;
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if (isnan(x) || isnan(y))
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return x + y;
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if (ux.i == uy.i)
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return y;
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ax = ux.i & 0x7fffffff;
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ay = uy.i & 0x7fffffff;
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if (ax == 0) {
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if (ay == 0)
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return y;
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ux.i = (uy.i & 0x80000000) | 1;
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} else if (ax > ay || ((ux.i ^ uy.i) & 0x80000000))
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ux.i--;
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else
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ux.i++;
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e = ux.i & 0x7f800000;
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/* raise overflow if ux.f is infinite and x is finite */
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if (e == 0x7f800000)
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FORCE_EVAL(x+x);
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/* raise underflow if ux.f is subnormal or zero */
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if (e == 0)
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FORCE_EVAL(x*x + ux.f*ux.f);
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return ux.f;
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}
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