37 lines
569 B
C
37 lines
569 B
C
#include <math.h>
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#include <stdint.h>
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float modff(float x, float *iptr)
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{
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union {float x; uint32_t n;} u = {x};
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uint32_t mask;
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int e;
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e = (int)(u.n>>23 & 0xff) - 0x7f;
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/* no fractional part */
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if (e >= 23) {
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*iptr = x;
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if (e == 0x80 && u.n<<9 != 0) { /* nan */
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return x;
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}
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u.n &= 0x80000000;
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return u.x;
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}
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/* no integral part */
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if (e < 0) {
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u.n &= 0x80000000;
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*iptr = u.x;
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return x;
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}
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mask = 0x007fffff>>e;
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if ((u.n & mask) == 0) {
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*iptr = x;
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u.n &= 0x80000000;
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return u.x;
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}
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u.n &= ~mask;
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*iptr = u.x;
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return x - *iptr;
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}
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