POSIX 2008 states that if the input for 'logb[f|l]' is a subnormal number
it should be treated as if it were normalized. This means the
implementation should calculate the log2 of the mantissa and add it to the
subnormal exponent (-126 for float and -1022 for double and IBM long
double). This patch takes care of that.
[BZ #6794]
Following Joseph comments about bug 6794, here is a proposed fix. It turned out
to be a large fix mainly because I had to move some file along to follow libm
files/names conventions.
Basically I have added wrappers (w_ilogb.c, w_ilogbf.c, w_ilogbl.c) that now calls
the symbol '__ieee754_ilogb'. The wrappers checks for '__ieee754_ilogb' output and
set the errno and raise exceptions as expected.
The '__ieee754_ilogb' is implemented in sysdeps. I have moved the 's_ilogb[f|l]' files
to e_ilogb[f|l] and renamed the '__ilogb[f|l]' to '__ieee754_ilogb[f|l]'.
I also found out a bug in i386 and x86-64 assembly coded ilogb implementation where
it raises a FE_DIVBYZERO when argument is '0.0'. I corrected this issue as well.
Finally I added the errno and FE_INVALID tests for 0.0, NaN and +-InF argument. Tested
on i386, x86-64, ppc32 and ppc64.
This patch addresses some IBM Long Double 128 fmal () test-ldouble.out
and test-ildoubl.out failures. If the ‘x’ and ‘y’ parameters are
finite values and ‘z’ is infinity, the result of fmal () should be ‘z’
not NaN.
Conflicts:
ChangeLog
__fe_nomask_env.
* sysdeps/powerpc/fpu/fe_nomask.c: Add libm_hidden_def.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/fe_nomask.c: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/fpu/fe_nomask.c: Likewise.
* sysdeps/powerpc/bits/fenv.h: Make safe for C++.
* sysdeps/unix/sysv/linux/powerpc/bits/mathinline.h: New file.
* sysdeps/powerpc/fpu/fegetexcept.c (__fegetexcept): Rename
function from fegetexcept and make old name weak alias.
* include/fenv.h: Declare __fegetexcept.
* sysdeps/powerpc/fpu/fedisblxcpt.c: Use __fegetexcept instead of
fegetexcept.
* sysdeps/powerpc/fpu/feenablxcpt.c: Likewise.
* sysdeps/powerpc/fpu/fraiseexcpt.c (__feraiseexcept): Avoid call
to fetestexcept.
* sysdeps/ieee754/ldbl-128ibm/s_log1pl.c (__log1pl): Use __frexpl
instead of frexpl to avoid local PLT.
* math/s_significandl.c (__significandl): Use __ilogbl instead of
ilogbl to avoid local PLT.
* sysdeps/ieee754/ldbl-128ibm/s_expm1l.c (__expm1l): Use __ldexpl
instead of ldexpl to avoid local PLT.
* sysdeps/ieee754/ldbl-128ibm/e_expl.c (__ieee754_expl): Use
__roundl not roundl to avoid local PLT.
* sysdeps/ieee754/ldbl-128/e_j0l.c: Use function names which avoid
local PLTs. Use __sincosl instead of separate sinl and cosl
calls.
* sysdeps/ieee754/ldbl-128/e_j1l.c: Likewise.
___new_wcstold_l): New weak aliases.
(strtold_l, wcstold_l): Use them as second argument for
long_double_symbol.
2007-08-10 Jakub Jelinek <jakub@redhat.com>
* sysdeps/ieee754/ldbl-128ibm/strtold_l.c (___new_strtold_l,
___new_wcstold_l): New weak aliases.
(strtold_l, wcstold_l): Use them as second argument for
long_double_symbol.
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>
(PRINT_FPHEX_LONG_DOUBLE): Fix printing numbers where lower double
is non-zero, but smaller than 2 * __DBL_MIN__.
* stdio-common/tst-sprintf2.c: New test.
* stdio-common/Makefile (tests): Add tst-sprintf2.
* math/test-misc.c (main): Don't run last batch of tests with
IBM long double format.
2007-03-27 Jakub Jelinek <jakub@redhat.com>
[BZ #3306]
* math/math_private.h (math_opt_barrier, math_force_eval): Define.
* sysdeps/i386/fpu/math_private.h: New file.
* sysdeps/x86_64/fpu/math_private.h: New file.
* math/s_nexttowardf.c (__nexttowardf): Use math_opt_barrier and
math_force_eval macros. Use "+m" constraint on asm rather than
"=m" and "m".
* math/s_nextafter.c (__nextafter): Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_nexttoward.c (__nexttoward):
Likewise.
* sysdeps/ieee754/flt-32/s_nextafterf.c (__nextafterf): Likewise.
* sysdeps/ieee754/ldbl-128/s_nexttoward.c (__nexttoward): Likewise.
* sysdeps/ieee754/ldbl-96/s_nexttoward.c (__nexttoward): Likewise.
* sysdeps/i386/fpu/s_nextafterl.c (__nextafterl): Use
math_opt_barrier and math_force_eval macros.
* sysdeps/ieee754/ldbl-128/s_nextafterl.c (__nextafterl): Likewise.
* sysdeps/ieee754/ldbl-96/s_nextafterl.c (__nextafterl): Likewise.
* sysdeps/i386/fpu/s_nexttoward.c: Include float.h.
(__nexttoward): Use math_opt_barrier and
math_force_eval macros. Use "+m" constraint on asm rather than
"=m" and "m". Only use asm to force double result if
FLT_EVAL_METHOD is 2.
* sysdeps/i386/fpu/s_nexttowardf.c: Include float.h.
(__nexttowardf): Use math_opt_barrier and
math_force_eval macros. Use "+m" constraint on asm rather than
"=m" and "m". Only use asm to force double result if
FLT_EVAL_METHOD is not 0.
* sysdeps/ieee754/ldbl-128ibm/s_nexttowardf.c: Include float.h.
(__nexttowardf): Use math_opt_barrier and
math_force_eval macros. If FLT_EVAL_METHOD is not 0, force
x to float using asm.
* sysdeps/ieee754/ldbl-opt/s_nexttowardfd.c: Include float.h.
(__nldbl_nexttowardf): Use math_opt_barrier and
math_force_eval macros. If FLT_EVAL_METHOD is not 0, force
x to float using asm.
* sysdeps/ieee754/ldbl-96/s_nexttowardf.c: Include float.h.
(__nexttowardf): Use math_opt_barrier and math_force_eval
macros. If FLT_EVAL_METHOD is not 0, force x to float using asm.
* math/bug-nextafter.c (zero, inf): New variables.
(main): Add new tests.
* math/bug-nexttoward.c (zero, inf): New variables.
(main): Add new tests.
