The ldbl-128ibm implementation of floorl is only correct in
round-to-nearest mode (in other modes, there are incorrect results and
overflow exceptions in some cases going beyond the incorrect signs of
zero results noted in bug 17899). It is also unnecessarily
complicated, rounding both high and low parts to the nearest integer
and then adjusting for the semantics of floor, when it seems more
natural to take the floor of the high part (__floor optimized inline
versions can be used), and that of the low part if the high part is an
integer. This patch makes it use that simpler approach, with a
canonicalization that works in all rounding modes (given that the only
way the result can be noncanonical is if taking the floor of a
negative noninteger low part increased its exponent).
Tested for powerpc, where over a thousand failures are removed from
test-ldouble.out (floorl problems affect many powl tests).
[BZ #17899]
* sysdeps/ieee754/ldbl-128ibm/math_ldbl.h (ldbl_canonicalize_int):
New function.
* sysdeps/ieee754/ldbl-128ibm/s_floorl.c (__floorl): Use __floor
on high and low parts then use ldbl_canonicalize_int if needed.
http://sourceware.org/ml/libc-alpha/2013-08/msg00085.html
Rid ourselves of ieee854.
* sysdeps/ieee754/ldbl-128ibm/ieee754.h (union ieee854_long_double):
Delete.
(IEEE854_LONG_DOUBLE_BIAS): Delete.
* sysdeps/ieee754/ldbl-128ibm/math_ldbl.h: Don't include ieee854
version of math_ldbl.h.
http://sourceware.org/ml/libc-alpha/2013-06/msg00919.html
I discovered a number of places where denormals and other corner cases
were being handled wrongly.
- printf_fphex.c: Testing for the low double exponent being zero is
unnecessary. If the difference in exponents is less than 53 then the
high double exponent must be nearing the low end of its range, and the
low double exponent hit rock bottom.
- ldbl2mpn.c: A denormal (ie. exponent of zero) value is treated as
if the exponent was one, so shift mantissa left by one. Code handling
normalisation of the low double mantissa lacked a test for shift count
greater than bits in type being shifted, and lacked anything to handle
the case where the difference in exponents is less than 53 as in
printf_fphex.c.
- math_ldbl.h (ldbl_extract_mantissa): Same as above, but worse, with
code testing for exponent > 1 for some reason, probably a typo for >= 1.
- math_ldbl.h (ldbl_insert_mantissa): Round the high double as per
mpn2ldbl.c (hi is odd or explicit mantissas non-zero) so that the
number we return won't change when applying ldbl_canonicalize().
Add missing overflow checks and normalisation of high mantissa.
Correct misleading comment: "The hidden bit of the lo mantissa is
zero" is not always true as can be seen from the code rounding the hi
mantissa. Also by inspection, lzcount can never be less than zero so
remove that test. Lastly, masking bitfields to their widths can be
left to the compiler.
- mpn2ldbl.c: The overflow checks here on rounding of high double were
just plain wrong. Incrementing the exponent must be accompanied by a
shift right of the mantissa to keep the value unchanged. Above notes
for ldbl_insert_mantissa are also relevant.
[BZ #15680]
* sysdeps/ieee754/ldbl-128ibm/e_rem_pio2l.c: Comment fix.
* sysdeps/ieee754/ldbl-128ibm/printf_fphex.c
(PRINT_FPHEX_LONG_DOUBLE): Tidy code by moving -53 into ediff
calculation. Remove unnecessary test for denormal exponent.
* sysdeps/ieee754/ldbl-128ibm/ldbl2mpn.c (__mpn_extract_long_double):
Correct handling of denormals. Avoid undefined shift behaviour.
Correct normalisation of low mantissa when low double is denormal.
* sysdeps/ieee754/ldbl-128ibm/math_ldbl.h
(ldbl_extract_mantissa): Likewise. Comment. Use uint64_t* for hi64.
(ldbl_insert_mantissa): Make both hi64 and lo64 parms uint64_t.
Correct normalisation of low mantissa. Test for overflow of high
mantissa and normalise.
(ldbl_nearbyint): Use more readable constant for two52.
* sysdeps/ieee754/ldbl-128ibm/mpn2ldbl.c
(__mpn_construct_long_double): Fix test for overflow of high
mantissa and correct normalisation. Avoid undefined shift.
http://sourceware.org/ml/libc-alpha/2013-07/msg00001.html
This patch starts the process of supporting powerpc64 little-endian
long double in glibc. IBM long double is an array of two ieee
doubles, so making union ibm_extended_long_double reflect this fact is
the correct way to access fields of the doubles.
* sysdeps/ieee754/ldbl-128ibm/ieee754.h
(union ibm_extended_long_double): Define as an array of ieee754_double.
(IBM_EXTENDED_LONG_DOUBLE_BIAS): Delete.
* sysdeps/ieee754/ldbl-128ibm/printf_fphex.c: Update all references
to ibm_extended_long_double and IBM_EXTENDED_LONG_DOUBLE_BIAS.
* sysdeps/ieee754/ldbl-128ibm/e_exp10l.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/e_expl.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/ldbl2mpn.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/math_ldbl.h: Likewise.
* sysdeps/ieee754/ldbl-128ibm/mpn2ldbl.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_nearbyintl.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/strtold_l.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/x2y2m1l.c: Likewise.
Jakub Jelinek <jakub@redhat.com>
Roland McGrath <roland@redhat.com>
Steven Munroe <sjmunroe@us.ibm.com>
Alan Modra <amodra@bigpond.net.au>
* sysdeps/powerpc/powerpc64/fpu/s_truncf.S: Comment fix.
* sysdeps/powerpc/powerpc32/fpu/s_truncf.S: Likewise.
* sysdeps/powerpc/powerpc64/fpu/s_llroundf.S: Likewise.
* sysdeps/powerpc/fpu/libm-test-ulps: Update.
* math/libm-test.inc (check_float_internal): Allow ulp <= 0.5.
(erfc_test): Don't run erfcl (27.0L) test if erfcl (27.0L) is
denormal.
[TEST_LDOUBLE] (ceil_test, floor_test, llrint_test, llround_test,
rint_test, round_test, trunc_test): Add new tests.
* sysdeps/powerpc/powerpc32/fpu/s_copysignl.S: New file.
* sysdeps/powerpc/powerpc32/fpu/s_fabs.S: New file.
* sysdeps/powerpc/powerpc32/fpu/s_fabsl.S: New file.
* sysdeps/powerpc/powerpc32/fpu/s_fdim.c: New file.
* sysdeps/powerpc/powerpc32/fpu/s_fmax.S: New file.
* sysdeps/powerpc/powerpc32/fpu/s_fmin.S: New file.
* sysdeps/powerpc/powerpc32/fpu/s_isnan.c: New file.
* sysdeps/powerpc/powerpc64/fpu/s_ceill.S: New file.
* sysdeps/powerpc/powerpc64/fpu/s_copysignl.S: New file.
* sysdeps/powerpc/powerpc64/fpu/s_fabs.S: New file.
* sysdeps/powerpc/powerpc64/fpu/s_fabsl.S: New file.
* sysdeps/powerpc/powerpc64/fpu/s_fdim.c: New file.
* sysdeps/powerpc/powerpc64/fpu/s_floorl.S: New file.
* sysdeps/powerpc/powerpc64/fpu/s_fmax.S: New file.
* sysdeps/powerpc/powerpc64/fpu/s_fmin.S: New file.
* sysdeps/powerpc/powerpc64/fpu/s_isnan.c: New file.
* sysdeps/powerpc/powerpc64/fpu/s_llrintl.S: New file.
* sysdeps/powerpc/powerpc64/fpu/s_llroundl.S: New file.
* sysdeps/powerpc/powerpc64/fpu/s_lrintl.S: New file.
* sysdeps/powerpc/powerpc64/fpu/s_lroundl.S: New file.
* sysdeps/powerpc/powerpc64/fpu/s_nearbyintl.S: New file.
* sysdeps/powerpc/powerpc64/fpu/s_rintl.S: New file.
* sysdeps/powerpc/powerpc64/fpu/s_roundl.S: New file.
* sysdeps/powerpc/powerpc64/fpu/s_truncl.S: New file.
* sysdeps/unix/sysv/linux/powerpc/Implies: New file.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/fpu/Implies: New file.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/Implies: New file.
* sysdeps/unix/sysv/linux/powerpc/configure.in: New file.
* sysdeps/unix/sysv/linux/powerpc/configure: New file.
* sysdeps/unix/sysv/linux/powerpc/bits/wordsize.h
(__LONG_DOUBLE_MATH_OPTIONAL): Define.
(__NO_LONG_DOUBLE_MATH): Define.
* sysdeps/unix/sysv/linux/powerpc/nldbl-abi.h: New file.
* sysdeps/powerpc/fpu/s_isnan.c: Include math_ldbl_opt.h.
* sysdeps/powerpc/powerpc64/fpu/s_ceil.S: Include math_ldbl_opt.h.
[LONG_DOUBLE_COMPAT] (ceill): Add compatibility symbols.
* sysdeps/powerpc/powerpc64/fpu/s_copysign.S: Include math_ldbl_opt.h.
[LONG_DOUBLE_COMPAT] (copysignl): Add compatibility symbols.
* sysdeps/powerpc/powerpc64/fpu/s_floor.S: Include math_ldbl_opt.h.
[LONG_DOUBLE_COMPAT] (floorl): Add compatibility symbols.
* sysdeps/powerpc/powerpc64/fpu/s_llrint.S: Include math_ldbl_opt.h.
[LONG_DOUBLE_COMPAT] (llrintl, lrintl): Add compatibility symbols.
* sysdeps/powerpc/powerpc64/fpu/s_llround.S: Include math_ldbl_opt.h.
[LONG_DOUBLE_COMPAT] (llroundl, lroundl): Add compatibility symbols.
* sysdeps/powerpc/powerpc64/fpu/s_rint.S: Include math_ldbl_opt.h.
[LONG_DOUBLE_COMPAT] (rintl): Add compatibility symbols.
* sysdeps/powerpc/powerpc64/fpu/s_round.S: Include math_ldbl_opt.h.
[LONG_DOUBLE_COMPAT] (roundl): Add compatibility symbols.
* sysdeps/powerpc/powerpc64/fpu/s_trunc.S: Include math_ldbl_opt.h.
[LONG_DOUBLE_COMPAT] (truncl): Add compatibility symbols.
* sysdeps/powerpc/powerpc32/fpu/s_ceil.S: Include math_ldbl_opt.h.
[LONG_DOUBLE_COMPAT] (ceill): Add compatibility symbols.
* sysdeps/powerpc/powerpc32/fpu/s_copysign.S: Include math_ldbl_opt.h.
[LONG_DOUBLE_COMPAT] (copysignl): Add compatibility symbols.
* sysdeps/powerpc/powerpc32/fpu/s_floor.S: Include math_ldbl_opt.h.
[LONG_DOUBLE_COMPAT] (floorl): Add compatibility symbols.
* sysdeps/powerpc/powerpc32/fpu/s_lrint.S: Include math_ldbl_opt.h.
[LONG_DOUBLE_COMPAT] (lrintl): Add compatibility symbols.
* sysdeps/powerpc/powerpc32/fpu/s_llrint.c: Include math_ldbl_opt.h.
[LONG_DOUBLE_COMPAT] (llrintl): Add compatibility symbols.
* sysdeps/powerpc/powerpc32/fpu/s_lround.S: Include math_ldbl_opt.h.
[LONG_DOUBLE_COMPAT] (lroundl): Add compatibility symbols.
* sysdeps/powerpc/powerpc32/fpu/s_rint.S: Include math_ldbl_opt.h.
[LONG_DOUBLE_COMPAT] (rintl): Add compatibility symbols.
* sysdeps/powerpc/powerpc32/fpu/s_round.S: Include math_ldbl_opt.h.
[LONG_DOUBLE_COMPAT] (roundl): Add compatibility symbols.
* sysdeps/powerpc/powerpc32/fpu/s_trunc.S: Include math_ldbl_opt.h.
[LONG_DOUBLE_COMPAT] (truncl): Add compatibility symbols.
* misc/qefgcvt_r.c [LDBL_MIN_10_EXP == -291] (FLOAT_MIN_10_NORM): New.
* sysdeps/powerpc/fpu/bits/mathdef.h (__NO_LONG_DOUBLE_MATH): Remove.
* sysdeps/powerpc/Implies: Add ieee754/ldbl-128ibm.
* sysdeps/powerpc/powerpc32/Implies: Remove powerpc/soft-fp.
* sysdeps/ieee754/ldbl-128ibm/Makefile: New file.
* sysdeps/ieee754/ldbl-128ibm/e_acoshl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/e_acosl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/e_asinl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/e_atan2l.c: New file.
* sysdeps/ieee754/ldbl-128ibm/e_atanhl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/e_coshl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/e_expl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/e_fmodl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/e_gammal_r.c: New file.
* sysdeps/ieee754/ldbl-128ibm/e_hypotl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/e_j0l.c: New file.
* sysdeps/ieee754/ldbl-128ibm/e_j1l.c: New file.
* sysdeps/ieee754/ldbl-128ibm/e_jnl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/e_lgammal_r.c: New file.
* sysdeps/ieee754/ldbl-128ibm/e_log10l.c: New file.
* sysdeps/ieee754/ldbl-128ibm/e_log2l.c: New file.
* sysdeps/ieee754/ldbl-128ibm/e_logl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/e_powl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/e_rem_pio2l.c: New file.
* sysdeps/ieee754/ldbl-128ibm/e_remainderl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/e_sinhl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/e_sqrtl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/ieee754.h: New file.
* sysdeps/ieee754/ldbl-128ibm/k_cosl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/k_sincosl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/k_sinl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/k_tanl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/ldbl2mpn.c: New file.
* sysdeps/ieee754/ldbl-128ibm/math_ldbl.h: New file.
* sysdeps/ieee754/ldbl-128ibm/mpn2ldbl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/printf_fphex.c: New file.
* sysdeps/ieee754/ldbl-128ibm/s_asinhl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/s_atanl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/s_cbrtl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/s_cosl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/s_erfl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/s_expm1l.c: New file.
* sysdeps/ieee754/ldbl-128ibm/s_fabsl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/s_finitel.c: New file.
* sysdeps/ieee754/ldbl-128ibm/s_fpclassifyl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/s_frexpl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/s_ilogbl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/s_isinfl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/s_isnanl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/s_log1pl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/s_logbl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/s_modfl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/s_nexttoward.c: New file.
* sysdeps/ieee754/ldbl-128ibm/s_nexttowardf.c: New file.
* sysdeps/ieee754/ldbl-128ibm/s_remquol.c: New file.
* sysdeps/ieee754/ldbl-128ibm/s_rintl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/s_scalblnl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/s_scalbnl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/s_signbitl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/s_sincosl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/s_sinl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/s_tanhl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/s_tanl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/s_truncl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/strtold_l.c: New file.
* sysdeps/ieee754/ldbl-128ibm/t_sincosl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/w_expl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/s_copysignl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/s_floorl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/s_llrintl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/s_llroundl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/s_roundl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/s_ceill.c: New file.
* sysdeps/ieee754/ldbl-128ibm/s_nearbyintl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/s_lrintl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/s_lroundl.c: New file.
* sysdeps/ieee754/ldbl-128/e_powl.c: Fix old comment.
