elf.h: add ELFCOMPRESS_ZSTD

[musl] / src / math / floorl.c

diff --git a/src/math/floorl.c b/src/math/floorl.c
index 08f6ba2..16aaec4 100644 (file)
--- a/src/math/floorl.c
+++ b/src/math/floorl.c
@@ -1,23 +1,3 @@
-/* origin: FreeBSD /usr/src/lib/msun/src/s_floorl.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.
- * ====================================================
- */
-/*
- * floorl(x)
- * Return x rounded toward -inf to integral value
- * Method:
- *      Bit twiddling.
- * Exception:
- *      Inexact flag raised if x not equal to floorl(x).
- */
-
 #include "libm.h"
 
 #if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
@@ -27,76 +7,28 @@ long double floorl(long double x)
 }
 #elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384
 
-#ifdef LDBL_IMPLICIT_NBIT
-#define MANH_SIZE       (LDBL_MANH_SIZE + 1)
-#define INC_MANH(u, c)  do {                                    \
-       uint64_t o = u.bits.manh;                               \
-       u.bits.manh += (c);                                     \
-       if (u.bits.manh < o)                                    \
-               u.bits.exp++;                                   \
-} while (0)
-#else
-#define MANH_SIZE       LDBL_MANH_SIZE
-#define INC_MANH(u, c)  do {                                    \
-       uint64_t o = u.bits.manh;                               \
-       u.bits.manh += (c);                                     \
-       if (u.bits.manh < o) {                                  \
-               u.bits.exp++;                                   \
-               u.bits.manh |= 1llu << (LDBL_MANH_SIZE - 1);    \
-       }                                                       \
-} while (0)
-#endif
-
-static const long double huge = 1.0e300;
+static const long double toint = 1/LDBL_EPSILON;
 
 long double floorl(long double x)
 {
-       union IEEEl2bits u = { .e = x };
-       int e = u.bits.exp - LDBL_MAX_EXP + 1;
+       union ldshape u = {x};
+       int e = u.i.se & 0x7fff;
+       long double y;
 
-       if (e < MANH_SIZE - 1) {
-               if (e < 0) {
-                       /* raise inexact if x != 0 */
-                       if (huge + x > 0.0)
-                               if (u.bits.exp > 0 ||
-                                   (u.bits.manh | u.bits.manl) != 0)
-                                       u.e = u.bits.sign ? -1.0 : 0.0;
-               } else {
-                       uint64_t m = ((1llu << MANH_SIZE) - 1) >> (e + 1);
-                       if (((u.bits.manh & m) | u.bits.manl) == 0)
-                               return x;  /* x is integral */
-                       if (u.bits.sign) {
-#ifdef LDBL_IMPLICIT_NBIT
-                               if (e == 0)
-                                       u.bits.exp++;
-                               else
-#endif
-                               INC_MANH(u, 1llu << (MANH_SIZE - e - 1));
-                       }
-                       /* raise inexact flag */
-                       if (huge + x > 0.0) {
-                               u.bits.manh &= ~m;
-                               u.bits.manl = 0;
-                       }
-               }
-       } else if (e < LDBL_MANT_DIG - 1) {
-               uint64_t m = (uint64_t)-1 >> (64 - LDBL_MANT_DIG + e + 1);
-               if ((u.bits.manl & m) == 0)
-                       return x;  /* x is integral */
-               if (u.bits.sign) {
-                       if (e == MANH_SIZE - 1)
-                               INC_MANH(u, 1);
-                       else {
-                               uint64_t o = u.bits.manl;
-                               u.bits.manl += 1llu << (LDBL_MANT_DIG - e - 1);
-                               if (u.bits.manl < o)   /* got a carry */
-                                       INC_MANH(u, 1);
-                       }
-               }
-               /* raise inexact flag */
-               if (huge + x > 0.0)
-                       u.bits.manl &= ~m;
+       if (e >= 0x3fff+LDBL_MANT_DIG-1 || x == 0)
+               return x;
+       /* y = int(x) - x, where int(x) is an integer neighbor of x */
+       if (u.i.se >> 15)
+               y = x - toint + toint - x;
+       else
+               y = x + toint - toint - x;
+       /* special case because of non-nearest rounding modes */
+       if (e <= 0x3fff-1) {
+               FORCE_EVAL(y);
+               return u.i.se >> 15 ? -1 : 0;
        }
-       return (u.e);
+       if (y > 0)
+               return x + y - 1;
+       return x + y;
 }
 #endif