76 lines
1.5 KiB
C
76 lines
1.5 KiB
C
#include "libc/math/libm.h"
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#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
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long double nextafterl(long double x, long double y)
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{
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return nextafter(x, y);
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}
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#elif LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384
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long double nextafterl(long double x, long double y)
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{
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union ldshape ux, uy;
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if (isnan(x) || isnan(y))
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return x + y;
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if (x == y)
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return y;
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ux.f = x;
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if (x == 0) {
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uy.f = y;
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ux.i.m = 1;
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ux.i.se = uy.i.se & 0x8000;
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} else if ((x < y) == !(ux.i.se & 0x8000)) {
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ux.i.m++;
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if (ux.i.m << 1 == 0) {
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ux.i.m = 1ULL << 63;
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ux.i.se++;
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}
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} else {
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if (ux.i.m << 1 == 0) {
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ux.i.se--;
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if (ux.i.se)
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ux.i.m = 0;
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}
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ux.i.m--;
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}
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/* raise overflow if ux is infinite and x is finite */
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if ((ux.i.se & 0x7fff) == 0x7fff)
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return x + x;
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/* raise underflow if ux is subnormal or zero */
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if ((ux.i.se & 0x7fff) == 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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#elif LDBL_MANT_DIG == 113 && LDBL_MAX_EXP == 16384
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long double nextafterl(long double x, long double y)
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{
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union ldshape ux, uy;
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if (isnan(x) || isnan(y))
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return x + y;
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if (x == y)
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return y;
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ux.f = x;
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if (x == 0) {
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uy.f = y;
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ux.i.lo = 1;
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ux.i.se = uy.i.se & 0x8000;
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} else if ((x < y) == !(ux.i.se & 0x8000)) {
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ux.i2.lo++;
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if (ux.i2.lo == 0)
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ux.i2.hi++;
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} else {
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if (ux.i2.lo == 0)
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ux.i2.hi--;
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ux.i2.lo--;
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}
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/* raise overflow if ux is infinite and x is finite */
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if ((ux.i.se & 0x7fff) == 0x7fff)
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return x + x;
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/* raise underflow if ux is subnormal or zero */
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if ((ux.i.se & 0x7fff) == 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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#endif
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