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authorUlrich Drepper <drepper@redhat.com>2007-06-08 03:08:45 +0000
committerUlrich Drepper <drepper@redhat.com>2007-06-08 03:08:45 +0000
commit7e3706ea254afe6f4a5f5bf4047d0d9967ce1207 (patch)
treedd2f50353b36cf3dc3c52c5c4aa9e6c3b1c80728 /sysdeps/ieee754
parent835abc5c0dfd1ba8aabeb52d46793b13702c708b (diff)
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* 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 <sjmunroe@us.ibm.com> * 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 <jakub@redhat.com> * 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 <jakub@redhat.com>
Diffstat (limited to 'sysdeps/ieee754')
-rw-r--r--sysdeps/ieee754/ldbl-128ibm/mpn2ldbl.c75
-rw-r--r--sysdeps/ieee754/ldbl-128ibm/s_fpclassifyl.c37
-rw-r--r--sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c97
3 files changed, 141 insertions, 68 deletions
diff --git a/sysdeps/ieee754/ldbl-128ibm/mpn2ldbl.c b/sysdeps/ieee754/ldbl-128ibm/mpn2ldbl.c
index 8a2d45e..21d1e62 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 3ca178a..6999abc 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 <drepper@cygnus.com>, 1997 and
Jakub Jelinek <jj@ultra.linux.cz>, 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 4f8aa7d..39d0e6a 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);