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-rw-r--r--src/math/nextafterl.c123
1 files changed, 65 insertions, 58 deletions
diff --git a/src/math/nextafterl.c b/src/math/nextafterl.c
index aec8ab40..611ea53d 100644
--- a/src/math/nextafterl.c
+++ b/src/math/nextafterl.c
@@ -1,21 +1,3 @@
-/* origin: FreeBSD /usr/src/lib/msun/src/s_nextafterl.c */
-/*
- * ====================================================
- * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
- *
- * Developed at SunPro, a Sun Microsystems, Inc. business.
- * Permission to use, copy, modify, and distribute this
- * software is freely granted, provided that this notice
- * is preserved.
- * ====================================================
- */
-/* IEEE functions
- * nextafter(x,y)
- * return the next machine floating-point number of x in the
- * direction toward y.
- * Special cases:
- */
-
#include "libm.h"
#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
@@ -23,55 +5,80 @@ long double nextafterl(long double x, long double y)
{
return nextafter(x, y);
}
-#elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384
+#elif LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384
+#define MSB ((uint64_t)1<<63)
long double nextafterl(long double x, long double y)
{
- volatile long double t;
- union IEEEl2bits ux, uy;
-
- ux.e = x;
- uy.e = y;
+ union ldshape ux, uy;
- if ((ux.bits.exp == 0x7fff && ((ux.bits.manh&~LDBL_NBIT)|ux.bits.manl) != 0) ||
- (uy.bits.exp == 0x7fff && ((uy.bits.manh&~LDBL_NBIT)|uy.bits.manl) != 0))
- return x+y; /* x or y is nan */
+ if (isnan(x) || isnan(y))
+ return x + y;
if (x == y)
- return y; /* x=y, return y */
- if (x == 0.0) {
- /* return +-minsubnormal */
- ux.bits.manh = 0;
- ux.bits.manl = 1;
+ return y;
+ ux.value = x;
+ if (x == 0) {
+ uy.value = y;
+ ux.bits.m = 1;
ux.bits.sign = uy.bits.sign;
- /* raise underflow flag */
- t = ux.e*ux.e;
- if (t == ux.e)
- return t;
- return ux.e;
- }
- if(x > 0.0 ^ x < y) { /* x -= ulp */
- if (ux.bits.manl == 0) {
- if ((ux.bits.manh&~LDBL_NBIT) == 0)
- ux.bits.exp--;
- ux.bits.manh = (ux.bits.manh - 1) | (ux.bits.manh & LDBL_NBIT);
+ } else if (x < y ^ ux.bits.sign) {
+ ux.bits.m++;
+ if ((ux.bits.m & ~MSB) == 0) {
+ ux.bits.m = MSB;
+ ux.bits.exp++;
}
- ux.bits.manl--;
- } else { /* x += ulp */
- ux.bits.manl++;
- if (ux.bits.manl == 0) {
- ux.bits.manh = (ux.bits.manh + 1) | (ux.bits.manh & LDBL_NBIT);
- if ((ux.bits.manh&~LDBL_NBIT)==0)
+ } else {
+ if ((ux.bits.m & ~MSB) == 0) {
+ ux.bits.exp--;
+ if (ux.bits.exp)
+ ux.bits.m = 0;
+ }
+ ux.bits.m--;
+ }
+ /* raise overflow if ux.value is infinite and x is finite */
+ if (ux.bits.exp == 0x7fff)
+ return x + x;
+ /* raise underflow if ux.value is subnormal or zero */
+ if (ux.bits.exp == 0) {
+ volatile float z = x*x + ux.value*ux.value;
+ }
+ return ux.value;
+}
+#elif LDBL_MANT_DIG == 113 && LDBL_MAX_EXP == 16384
+long double nextafterl(long double x, long double y)
+{
+ union ldshape ux, uy;
+
+ if (isnan(x) || isnan(y))
+ return x + y;
+ if (x == y)
+ return y;
+ ux.value = x;
+ if (x == 0) {
+ uy.value = y;
+ ux.bits.mlo = 1;
+ ux.bits.sign = uy.bits.sign;
+ } else if (x < y ^ ux.bits.sign) {
+ ux.bits.mlo++;
+ if (ux.bits.mlo == 0) {
+ ux.bits.mhi++;
+ if (ux.bits.mhi == 0)
ux.bits.exp++;
}
+ } else {
+ if (ux.bits.mlo == 0) {
+ if (ux.bits.mhi == 0)
+ ux.bits.exp--;
+ ux.bits.mhi--;
+ }
+ ux.bits.mlo--;
}
- if (ux.bits.exp == 0x7fff) /* overflow */
- return x+x;
- if (ux.bits.exp == 0) { /* underflow */
- mask_nbit_l(ux);
- /* raise underflow flag */
- t = ux.e * ux.e;
- if (t != ux.e)
- return ux.e;
+ /* raise overflow if ux.value is infinite and x is finite */
+ if (ux.bits.exp == 0x7fff)
+ return x + x;
+ /* raise underflow if ux.value is subnormal or zero */
+ if (ux.bits.exp == 0) {
+ volatile float z = x*x + ux.value*ux.value;
}
- return ux.e;
+ return ux.value;
}
#endif