From 7e3706ea254afe6f4a5f5bf4047d0d9967ce1207 Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Fri, 8 Jun 2007 03:08:45 +0000 Subject: * sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c (nextafterl): Remove unused ily variable. Fix nextafterl on +-__LDBL_MAX__ and +-Inf. Remove unreachable code at the end. 2007-06-01 Steven Munroe * sysdeps/ieee754/ldbl-128ibm/s_fpclassifyl.c: Correct description of ldbl-128ibm in comment. (fpclassifyl): Correct classification of denormals. * sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c (nextafterl): Correct return value for MIN denormal. Rewrite using long double math too correctly handle denormals and canonicalize the results. 2007-06-05 Jakub Jelinek * sysdeps/ieee754/ldbl-128ibm/mpn2ldbl.c (__mpn_construct_long_double): Fix conversion where result ought to be smaller than __LDBL_MIN__, or the low double should be denormal. Fix decision where to negate low double - honor round to even rules. * stdio-common/tst-sprintf2.c: Include string.h. (COMPARE_LDBL): Define. (TEST): Also test whether a string hexadecimal float representation can be parsed back to the number. (main): Add a couple of further tests. 2007-06-04 Jakub Jelinek --- sysdeps/ieee754/ldbl-128ibm/mpn2ldbl.c | 75 ++++++++++++++++++---- sysdeps/ieee754/ldbl-128ibm/s_fpclassifyl.c | 37 +++++++---- sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c | 97 ++++++++++++++++------------- 3 files changed, 141 insertions(+), 68 deletions(-) (limited to 'sysdeps') diff --git a/sysdeps/ieee754/ldbl-128ibm/mpn2ldbl.c b/sysdeps/ieee754/ldbl-128ibm/mpn2ldbl.c index 8a2d45e2d8..21d1e62dab 100644 --- a/sysdeps/ieee754/ldbl-128ibm/mpn2ldbl.c +++ b/sysdeps/ieee754/ldbl-128ibm/mpn2ldbl.c @@ -1,4 +1,4 @@ -/* Copyright (C) 1995, 1996, 1997, 1998, 1999, 2002, 2003, 2004, 2006 +/* Copyright (C) 1995, 1996, 1997, 1998, 1999, 2002, 2003, 2004, 2006, 2007 Free Software Foundation, Inc. This file is part of the GNU C Library. @@ -31,19 +31,20 @@ long double __mpn_construct_long_double (mp_srcptr frac_ptr, int expt, int sign) { union ibm_extended_long_double u; - unsigned long hidden2, lzcount; + unsigned long lzcount; unsigned long long hi, lo; + int exponent2; u.ieee.negative = sign; u.ieee.negative2 = sign; u.ieee.exponent = expt + IBM_EXTENDED_LONG_DOUBLE_BIAS; - u.ieee.exponent2 = expt - 53 + IBM_EXTENDED_LONG_DOUBLE_BIAS; + u.ieee.exponent2 = 0; + exponent2 = expt - 53 + IBM_EXTENDED_LONG_DOUBLE_BIAS; #if BITS_PER_MP_LIMB == 32 /* The low order 53 bits (52 + hidden) go into the lower double */ lo = frac_ptr[0]; lo |= (frac_ptr[1] & ((1LL << (53 - 32)) - 1)) << 32; - hidden2 = (frac_ptr[1] >> (52 - 32)) & ((mp_limb_t) 1); /* The high order 53 bits (52 + hidden) go into the upper double */ hi = (frac_ptr[1] >> (53 - 32)) & ((1 << 11) - 1); hi |= ((unsigned long long) frac_ptr[2]) << 11; @@ -51,7 +52,6 @@ __mpn_construct_long_double (mp_srcptr frac_ptr, int expt, int sign) #elif BITS_PER_MP_LIMB == 64 /* The low order 53 bits (52 + hidden) go into the lower double */ lo = frac_ptr[0] & (((mp_limb_t) 1 << 53) - 1); - hidden2 = (frac_ptr[0] >> 52) & ((mp_limb_t) 1); /* The high order 53 bits (52 + hidden) go into the upper double */ hi = (frac_ptr[0] >> 53) & (((mp_limb_t) 1 << 11) - 1); hi |= (frac_ptr[1] << 11); @@ -59,14 +59,62 @@ __mpn_construct_long_double (mp_srcptr frac_ptr, int expt, int sign) #error "mp_limb size " BITS_PER_MP_LIMB "not accounted for" #endif + if ((hi & (1LL << 52)) == 0 && (hi | lo) != 0) + { + /* denormal number */ + unsigned long long val = hi ? hi : lo; + + if (sizeof (val) == sizeof (long)) + lzcount = __builtin_clzl (val); + else if ((val >> 32) != 0) + lzcount = __builtin_clzl ((long) (val >> 32)); + else + lzcount = __builtin_clzl ((long) val) + 32; + if (hi) + lzcount = lzcount - 11; + else + lzcount = lzcount + 42; + + if (lzcount > u.ieee.exponent) + { + lzcount = u.ieee.exponent; + u.ieee.exponent = 0; + exponent2 -= lzcount; + } + else + { + u.ieee.exponent -= (lzcount - 1); + exponent2 -= (lzcount - 1); + } + + if (lzcount <= 53) + { + hi = (hi << lzcount) | (lo >> (53 - lzcount)); + lo = (lo << lzcount) & ((1LL << 53) - 1); + } + else + { + hi = lo << (lzcount - 53); + lo = 0; + } + } + if (lo != 0L) { /* hidden2 bit of low double controls rounding of the high double. - If hidden2 is '1' then round up hi and adjust lo (2nd mantissa) + If hidden2 is '1' and either the explicit mantissa is non-zero + or hi is odd, then round up hi and adjust lo (2nd mantissa) plus change the sign of the low double to compensate. */ - if (hidden2) + if ((lo & (1LL << 52)) != 0 + && ((hi & 1) != 0 || (lo & ((1LL << 52) - 1)))) { hi++; + if ((hi & ((1LL << 52) - 1)) == 0) + { + if ((hi & (1LL << 53)) != 0) + hi -= 1LL << 52; + u.ieee.exponent++; + } u.ieee.negative2 = !sign; lo = (1LL << 53) - lo; } @@ -85,17 +133,18 @@ __mpn_construct_long_double (mp_srcptr frac_ptr, int expt, int sign) if (lzcount > 0) { lo = lo << lzcount; - u.ieee.exponent2 = u.ieee.exponent2 - lzcount; + exponent2 = exponent2 - lzcount; } + if (exponent2 > 0) + u.ieee.exponent2 = exponent2; + else + lo >>= 1 - exponent2; } else - { - u.ieee.negative2 = 0; - u.ieee.exponent2 = 0; - } + u.ieee.negative2 = 0; u.ieee.mantissa3 = lo & 0xffffffffLL; - u.ieee.mantissa2 = (lo >> 32) & 0xffffff; + u.ieee.mantissa2 = (lo >> 32) & 0xfffff; u.ieee.mantissa1 = hi & 0xffffffffLL; u.ieee.mantissa0 = (hi >> 32) & ((1LL << (LDBL_MANT_DIG - 86)) - 1); diff --git a/sysdeps/ieee754/ldbl-128ibm/s_fpclassifyl.c b/sysdeps/ieee754/ldbl-128ibm/s_fpclassifyl.c index 3ca178a3c5..6999abc250 100644 --- a/sysdeps/ieee754/ldbl-128ibm/s_fpclassifyl.c +++ b/sysdeps/ieee754/ldbl-128ibm/s_fpclassifyl.c @@ -1,5 +1,5 @@ /* Return classification value corresponding to argument. - Copyright (C) 1997,1999,2002,2004,2006 Free Software Foundation, Inc. + Copyright (C) 1997,1999,2002,2004,2006,2007 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper , 1997 and Jakub Jelinek , 1999. @@ -30,14 +30,16 @@ * -NaN fffn nnnn nnnn nnnn xxxx xxxx xxxx xxxx * +Inf 7ff0 0000 0000 0000 xxxx xxxx xxxx xxxx * -Inf fff0 0000 0000 0000 xxxx xxxx xxxx xxxx - * +0 0000 0000 0000 0000 - * -0 8000 0000 0000 0000 - * +normal 001n nnnn nnnn nnnn (smallest) - * -normal 801n nnnn nnnn nnnn (smallest) - * +normal 7fen nnnn nnnn nnnn (largest) - * -normal ffen nnnn nnnn nnnn (largest) - * +denorm 000n nnnn nnnn nnnn - * -denorm 800n nnnn nnnn nnnn + * +0 0000 0000 0000 0000 xxxx xxxx xxxx xxxx + * -0 8000 0000 0000 0000 xxxx xxxx xxxx xxxx + * +normal 0360 0000 0000 0000 0000 0000 0000 0000 (smallest) + * -normal 8360 0000 0000 0000 0000 0000 0000 0000 (smallest) + * +normal 7fef ffff ffff ffff 7c8f ffff ffff fffe (largest) + * +normal ffef ffff ffff ffff fc8f ffff ffff fffe (largest) + * +denorm 0360 0000 0000 0000 8000 0000 0000 0001 (largest) + * -denorm 8360 0000 0000 0000 0000 0000 0000 0001 (largest) + * +denorm 000n nnnn nnnn nnnn xxxx xxxx xxxx xxxx + * -denorm 800n nnnn nnnn nnnn xxxx xxxx xxxx xxxx */ int @@ -59,12 +61,23 @@ ___fpclassifyl (long double x) /* +/-zero or +/- normal or +/- denormal */ if (hx & 0x7fffffffffffffffULL) { /* +/- normal or +/- denormal */ - if ((hx & 0x7ff0000000000000ULL) >= 0x0360000000000000ULL) { + if ((hx & 0x7ff0000000000000ULL) > 0x0360000000000000ULL) { /* +/- normal */ retval = FP_NORMAL; } else { - /* +/- denormal */ - retval = FP_SUBNORMAL; + if ((hx & 0x7ff0000000000000ULL) == 0x0360000000000000ULL) { + if ((lx & 0x7fffffffffffffff) /* lower is non-zero */ + && ((lx^hx) & 0x8000000000000000ULL)) { /* and sign differs */ + /* +/- denormal */ + retval = FP_SUBNORMAL; + } else { + /* +/- normal */ + retval = FP_NORMAL; + } + } else { + /* +/- denormal */ + retval = FP_SUBNORMAL; + } } } else { /* +/- zero */ diff --git a/sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c b/sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c index 4f8aa7dec1..39d0e6a5e3 100644 --- a/sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c +++ b/sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c @@ -35,7 +35,7 @@ static char rcsid[] = "$NetBSD: $"; long double x,y; #endif { - int64_t hx,hy,ihx,ihy,ilx,ily; + int64_t hx,hy,ihx,ihy,ilx; u_int64_t lx,ly; GET_LDOUBLE_WORDS64(hx,lx,x); @@ -43,7 +43,6 @@ static char rcsid[] = "$NetBSD: $"; ihx = hx&0x7fffffffffffffffLL; /* |hx| */ ilx = lx&0x7fffffffffffffffLL; /* |lx| */ ihy = hy&0x7fffffffffffffffLL; /* |hy| */ - ily = ly&0x7fffffffffffffffLL; /* |ly| */ if((((ihx&0x7ff0000000000000LL)==0x7ff0000000000000LL)&& ((ihx&0x000fffffffffffffLL)!=0)) || /* x is nan */ @@ -54,54 +53,66 @@ static char rcsid[] = "$NetBSD: $"; return y; /* x=y, return y */ if(ihx == 0 && ilx == 0) { /* x == 0 */ long double u; - SET_LDOUBLE_WORDS64(x,hy&0x8000000000000000ULL,1);/* return +-minsubnormal */ - u = math_opt_barrier (u); + hy = (hy & 0x8000000000000000ULL) | 1; + SET_LDOUBLE_WORDS64(x,hy,0ULL);/* return +-minsubnormal */ + u = math_opt_barrier (x); u = u * u; math_force_eval (u); /* raise underflow flag */ return x; } - if(ihx>=0) { /* x > 0 */ - if(ihx>ihy||((ihx==ihy)&&(ilx>ily))) { /* x > y, x -= ulp */ - - if(ilx==0) - hx--; - else - lx--; - } else { /* x < y, x += ulp */ - if((hx==0x7fefffffffffffffLL)&&(lx==0x7c8ffffffffffffeLL)) - { - SET_LDOUBLE_WORDS64(x,0x7ff0000000000000,0x8000000000000000); - return x; - } - else if((hx==0xffefffffffffffffLL)&&(lx==0xfc8ffffffffffffeLL)) - { - SET_LDOUBLE_WORDS64(x,0xfff0000000000000,0x8000000000000000); - return x; - } - else if((lx&0x7fffffffffffffff)==0) hx++; - else - lx++; + + long double u; + if(x > y) { /* x > y, x -= ulp */ + if((hx==0xffefffffffffffffLL)&&(lx==0xfc8ffffffffffffeLL)) + return x+x; /* overflow, return -inf */ + if (hx >= 0x7ff0000000000000LL) { + SET_LDOUBLE_WORDS64(u,0x7fefffffffffffffLL,0x7c8ffffffffffffeLL); + return u; } - } else { /* x < 0 */ - if(ihy>=0||ihx>ihy||((ihx==ihy)&&(ilx>ily))){/* x < y, x -= ulp */ - if((lx&0x7fffffffffffffff)==0) - hx--; - else - lx--; - } else { /* x > y, x += ulp */ - if((lx&0x7fffffffffffffff)==0) hx++; - else - lx++; + if(ihx <= 0x0360000000000000LL) { /* x <= LDBL_MIN */ + u = math_opt_barrier (x); + x -= __LDBL_DENORM_MIN__; + if (ihx < 0x0360000000000000LL + || (hx > 0 && (int64_t) lx <= 0) + || (hx < 0 && (int64_t) lx > 1)) { + u = u * u; + math_force_eval (u); /* raise underflow flag */ + } + return x; } + if (ihx < 0x06a0000000000000LL) { /* ulp will denormal */ + SET_LDOUBLE_WORDS64(u,(hx&0x7ff0000000000000LL),0ULL); + u *= 0x1.0000000000000p-105L; + } else + SET_LDOUBLE_WORDS64(u,(hx&0x7ff0000000000000LL)-0x0690000000000000LL,0ULL); + return x - u; + } else { /* x < y, x += ulp */ + if((hx==0x7fefffffffffffffLL)&&(lx==0x7c8ffffffffffffeLL)) + return x+x; /* overflow, return +inf */ + if ((u_int64_t) hx >= 0xfff0000000000000ULL) { + SET_LDOUBLE_WORDS64(u,0xffefffffffffffffLL,0xfc8ffffffffffffeLL); + return u; + } + if(ihx <= 0x0360000000000000LL) { /* x <= LDBL_MIN */ + u = math_opt_barrier (x); + x += __LDBL_DENORM_MIN__; + if (ihx < 0x0360000000000000LL + || (hx > 0 && (int64_t) lx < 0 && lx != 0x8000000000000001LL) + || (hx < 0 && (int64_t) lx >= 0)) { + u = u * u; + math_force_eval (u); /* raise underflow flag */ + } + if (x == 0.0L) /* handle negative __LDBL_DENORM_MIN__ case */ + x = -0.0L; + return x; + } + if (ihx < 0x06a0000000000000LL) { /* ulp will denormal */ + SET_LDOUBLE_WORDS64(u,(hx&0x7ff0000000000000LL),0ULL); + u *= 0x1.0000000000000p-105L; + } else + SET_LDOUBLE_WORDS64(u,(hx&0x7ff0000000000000LL)-0x0690000000000000LL,0ULL); + return x + u; } - hy = hx&0x7ff0000000000000LL; - if(hy==0x7ff0000000000000LL) return x+x;/* overflow */ - if(hy==0) { - long double u = x * x; /* underflow */ - math_force_eval (u); /* raise underflow flag */ - } - SET_LDOUBLE_WORDS64(x,hx,lx); - return x; } strong_alias (__nextafterl, __nexttowardl) long_double_symbol (libm, __nextafterl, nextafterl); -- cgit 1.4.1