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85422c2acb
nextafter and nexttoward fail to set errno on overflow and underflow. This patch makes them do so in cases that should include all the cases where such errno setting is required by glibc's goals for when to set errno (but not all cases of underflow where the result is nonzero and so glibc's goals do not require errno setting). Tested for x86_64, x86, mips64 and powerpc. [BZ #6799] * math/s_nextafter.c: Include <errno.h>. (__nextafter): Set errno on overflow and underflow. * math/s_nexttowardf.c: Include <errno.h>. (__nexttowardf): Set errno on overflow and underflow. * sysdeps/i386/fpu/s_nextafterl.c: Include <errno.h>. (__nextafterl): Set errno on overflow and underflow. * sysdeps/i386/fpu/s_nexttoward.c: Include <errno.h>. (__nexttoward): Set errno on overflow and underflow. * sysdeps/i386/fpu/s_nexttowardf.c: Include <errno.h>. (__nexttowardf): Set errno on overflow and underflow. * sysdeps/ieee754/flt-32/s_nextafterf.c: Include <errno.h>. (__nextafterf): Set errno on overflow and underflow. * sysdeps/ieee754/ldbl-128/s_nextafterl.c: Include <errno.h>. (__nextafterl): Set errno on overflow and underflow. * sysdeps/ieee754/ldbl-128/s_nexttoward.c: Include <errno.h>. (__nexttoward): Set errno on overflow and underflow. * sysdeps/ieee754/ldbl-128/s_nexttowardf.c: Include <errno.h>. (__nexttowardf): Set errno on overflow and underflow. * sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c: Include <errno.h>. (__nextafterl): Set errno on overflow and underflow. * sysdeps/ieee754/ldbl-128ibm/s_nexttoward.c: Include <errno.h>. (__nexttoward): Set errno on overflow and underflow. * sysdeps/ieee754/ldbl-128ibm/s_nexttowardf.c: Include <errno.h>. (__nexttowardf): Set errno on overflow and underflow. * sysdeps/ieee754/ldbl-96/s_nexttoward.c: Include <errno.h>. (__nexttoward): Set errno on overflow and underflow. * sysdeps/ieee754/ldbl-96/s_nexttowardf.c: Include <errno.h>. (__nexttowardf): Set errno on overflow and underflow. * sysdeps/ieee754/ldbl-opt/s_nexttowardfd.c: Include <errno.h>. (__nldbl_nexttowardf): Set errno on overflow and underflow. * sysdeps/m68k/m680x0/fpu/s_nextafterl.c: Include <errno.h>. (__nextafterl): Set errno on overflow and underflow. * math/libm-test.inc (nextafter_test_data): Do not allow errno setting to be missing on overflow. Add more tests. (nexttoward_test_data): Likewise.
158 lines
5.1 KiB
C
158 lines
5.1 KiB
C
/* s_nextafterl.c -- long double version of s_nextafter.c.
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* Conversion to IEEE quad long double by Jakub Jelinek, jj@ultra.linux.cz.
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*/
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/*
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunPro, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*/
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#if defined(LIBM_SCCS) && !defined(lint)
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static char rcsid[] = "$NetBSD: $";
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#endif
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/* IEEE functions
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* nextafterl(x,y)
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* return the next machine floating-point number of x in the
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* direction toward y.
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* Special cases:
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*/
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#include <errno.h>
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#include <float.h>
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#include <math.h>
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#include <math_private.h>
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#include <math_ldbl_opt.h>
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long double __nextafterl(long double x, long double y)
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{
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int64_t hx, hy, ihx, ihy, lx;
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double xhi, xlo, yhi;
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ldbl_unpack (x, &xhi, &xlo);
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EXTRACT_WORDS64 (hx, xhi);
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EXTRACT_WORDS64 (lx, xlo);
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yhi = ldbl_high (y);
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EXTRACT_WORDS64 (hy, yhi);
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ihx = hx&0x7fffffffffffffffLL; /* |hx| */
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ihy = hy&0x7fffffffffffffffLL; /* |hy| */
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if((ihx>0x7ff0000000000000LL) || /* x is nan */
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(ihy>0x7ff0000000000000LL)) /* y is nan */
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return x+y; /* signal the nan */
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if(x==y)
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return y; /* x=y, return y */
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if(ihx == 0) { /* x == 0 */
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long double u; /* return +-minsubnormal */
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hy = (hy & 0x8000000000000000ULL) | 1;
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INSERT_WORDS64 (yhi, hy);
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x = yhi;
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u = math_opt_barrier (x);
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u = u * u;
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math_force_eval (u); /* raise underflow flag */
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return x;
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}
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long double u;
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if(x > y) { /* x > y, x -= ulp */
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/* This isn't the largest magnitude correctly rounded
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long double as you can see from the lowest mantissa
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bit being zero. It is however the largest magnitude
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long double with a 106 bit mantissa, and nextafterl
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is insane with variable precision. So to make
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nextafterl sane we assume 106 bit precision. */
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if((hx==0xffefffffffffffffLL)&&(lx==0xfc8ffffffffffffeLL)) {
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u = x+x; /* overflow, return -inf */
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math_force_eval (u);
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__set_errno (ERANGE);
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return y;
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}
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if (hx >= 0x7ff0000000000000LL) {
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u = 0x1.fffffffffffff7ffffffffffff8p+1023L;
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return u;
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}
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if(ihx <= 0x0360000000000000LL) { /* x <= LDBL_MIN */
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u = math_opt_barrier (x);
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x -= LDBL_TRUE_MIN;
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if (ihx < 0x0360000000000000LL
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|| (hx > 0 && lx <= 0)
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|| (hx < 0 && lx > 1)) {
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u = u * u;
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math_force_eval (u); /* raise underflow flag */
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__set_errno (ERANGE);
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}
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return x;
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}
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/* If the high double is an exact power of two and the low
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double is the opposite sign, then 1ulp is one less than
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what we might determine from the high double. Similarly
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if X is an exact power of two, and positive, because
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making it a little smaller will result in the exponent
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decreasing by one and normalisation of the mantissa. */
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if ((hx & 0x000fffffffffffffLL) == 0
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&& ((lx != 0 && (hx ^ lx) < 0)
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|| (lx == 0 && hx >= 0)))
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ihx -= 1LL << 52;
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if (ihx < (106LL << 52)) { /* ulp will denormal */
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INSERT_WORDS64 (yhi, ihx & (0x7ffLL<<52));
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u = yhi * 0x1p-105;
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} else {
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INSERT_WORDS64 (yhi, (ihx & (0x7ffLL<<52))-(105LL<<52));
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u = yhi;
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}
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return x - u;
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} else { /* x < y, x += ulp */
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if((hx==0x7fefffffffffffffLL)&&(lx==0x7c8ffffffffffffeLL)) {
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u = x+x; /* overflow, return +inf */
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math_force_eval (u);
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__set_errno (ERANGE);
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return y;
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}
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if ((uint64_t) hx >= 0xfff0000000000000ULL) {
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u = -0x1.fffffffffffff7ffffffffffff8p+1023L;
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return u;
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}
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if(ihx <= 0x0360000000000000LL) { /* x <= LDBL_MIN */
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u = math_opt_barrier (x);
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x += LDBL_TRUE_MIN;
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if (ihx < 0x0360000000000000LL
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|| (hx > 0 && lx < 0 && lx != 0x8000000000000001LL)
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|| (hx < 0 && lx >= 0)) {
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u = u * u;
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math_force_eval (u); /* raise underflow flag */
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__set_errno (ERANGE);
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}
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if (x == 0.0L) /* handle negative LDBL_TRUE_MIN case */
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x = -0.0L;
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return x;
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}
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/* If the high double is an exact power of two and the low
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double is the opposite sign, then 1ulp is one less than
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what we might determine from the high double. Similarly
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if X is an exact power of two, and negative, because
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making it a little larger will result in the exponent
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decreasing by one and normalisation of the mantissa. */
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if ((hx & 0x000fffffffffffffLL) == 0
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&& ((lx != 0 && (hx ^ lx) < 0)
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|| (lx == 0 && hx < 0)))
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ihx -= 1LL << 52;
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if (ihx < (106LL << 52)) { /* ulp will denormal */
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INSERT_WORDS64 (yhi, ihx & (0x7ffLL<<52));
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u = yhi * 0x1p-105;
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} else {
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INSERT_WORDS64 (yhi, (ihx & (0x7ffLL<<52))-(105LL<<52));
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u = yhi;
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}
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return x + u;
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}
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}
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strong_alias (__nextafterl, __nexttowardl)
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long_double_symbol (libm, __nextafterl, nextafterl);
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long_double_symbol (libm, __nexttowardl, nexttowardl);
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