The dbl-64 version of acos returns sNaN for sNaN arguments. This
patch fixes it to add NaN arguments to themselves so that qNaN is
returned in this case.
Tested for x86_64 and x86.
[BZ #20212]
* sysdeps/ieee754/dbl-64/e_asin.c (__ieee754_acos): Add NaN
argument to itself.
* math/libm-test.inc (acos_test_data): Add sNaN tests.
The ldbl-128ibm implementations of ceill, floorl, roundl, truncl,
rintl and nearbyintl wrongly return an sNaN when given an sNaN
argument. This patch fixes them to add such an argument to itself to
turn it into a quiet NaN. (The code structure means this "else" case
applies to any argument which is zero or not finite; it's OK to do
this in all such cases.)
Tested for powerpc.
[BZ #20156]
* sysdeps/ieee754/ldbl-128ibm/s_ceill.c (__ceill): Add high part
to itself when zero or not finite.
* sysdeps/ieee754/ldbl-128ibm/s_floorl.c (__floorl): Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_rintl.c (__rintl): Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_roundl.c (__roundl): Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_truncl.c (__truncl): Likewise.
The ldbl-128ibm implementation of sqrtl wrongly returns an sNaN for
signaling NaN arguments. This patch fixes it to quiet its argument,
using the same x * x + x return for infinities and NaNs as the dbl-64
implementation uses to ensure that +Inf maps to +Inf while -Inf and
NaN map to NaN.
Tested for powerpc.
[BZ #20153]
* sysdeps/ieee754/ldbl-128ibm/e_sqrtl.c (__ieee754_sqrtl): Return
x * x + x for infinities and NaNs.
The ldbl-128 implementations of j0l, j1l, y0l, y1l (also used for
ldbl-128ibm) return an sNaN argument unchanged. This patch fixes them
to add a NaN argument to itself to quiet it before return.
Tested for mips64.
[BZ #20151]
* sysdeps/ieee754/ldbl-128/e_j0l.c (__ieee754_j0l): Add NaN
argument to itself before returning result.
(__ieee754_y0l): Likewise.
* sysdeps/ieee754/ldbl-128/e_j1l.c (__ieee754_j1l): Likewise.
(__ieee754_y1l).
C99 and C11 allow but do not require ceil, floor, round and trunc to
raise the "inexact" exception for noninteger arguments. TS 18661-1
requires that this exception not be raised by these functions. This
aligns them with general IEEE semantics, where "inexact" is only
raised if the final step of rounding the infinite-precision result to
the result type is inexact; for these functions, the
infinite-precision integer result is always representable in the
result type, so "inexact" should never be raised.
The generic implementations of ceil, floor and round functions contain
code to force "inexact" to be raised. This patch removes it for round
functions to align them with TS 18661-1 in this regard. The tests
*are* updated by this patch; there are fewer architecture-specific
versions than for ceil and floor, and I fixed the powerpc ones some
time ago. If any others still have the issue, as shown by tests for
round failing with spurious exceptions, they can be fixed separately
by architecture maintainers or others.
Tested for x86_64, x86 and mips64.
[BZ #15479]
* sysdeps/ieee754/dbl-64/s_round.c (huge): Remove variable.
(__round): Do not force "inexact" exception.
* sysdeps/ieee754/dbl-64/wordsize-64/s_round.c (huge): Remove
variable.
(__round): Do not force "inexact" exception.
* sysdeps/ieee754/flt-32/s_roundf.c (huge): Remove variable.
(__roundf): Do not force "inexact" exception.
* sysdeps/ieee754/ldbl-128/s_roundl.c (huge): Remove variable.
(__roundl): Do not force "inexact" exception.
* sysdeps/ieee754/ldbl-96/s_roundl.c (huge): Remove variable.
(__roundl): Do not force "inexact" exception.
* math/libm-test.inc (round_test_data): Do not allow spurious
"inexact" exceptions.
C99 and C11 allow but do not require ceil, floor, round and trunc to
raise the "inexact" exception for noninteger arguments. TS 18661-1
requires that this exception not be raised by these functions. This
aligns them with general IEEE semantics, where "inexact" is only
raised if the final step of rounding the infinite-precision result to
the result type is inexact; for these functions, the
infinite-precision integer result is always representable in the
result type, so "inexact" should never be raised.
The generic implementations of ceil, floor and round functions contain
code to force "inexact" to be raised. This patch removes it for floor
functions to align them with TS 18661-1 in this regard. Note that
some architecture-specific versions may still raise "inexact", so the
tests are not updated and the bug is not yet fixed.
Tested for x86_64, x86 and mips64.
[BZ #15479]
* sysdeps/ieee754/dbl-64/s_floor.c: Do not mention "inexact"
exception in comment.
(huge): Remove variable.
(__floor): Do not force "inexact" exception.
* sysdeps/ieee754/dbl-64/wordsize-64/s_floor.c: Do not mention
"inexact" exception in comment.
(huge): Remove variable.
(__floor): Do not force "inexact" exception.
* sysdeps/ieee754/flt-32/s_floorf.c: Do not mention "inexact"
exception in comment.
(huge): Remove variable.
(__floorf): Do not force "inexact" exception.
* sysdeps/ieee754/ldbl-128/s_floorl.c: Do not mention "inexact"
exception in comment.
(huge): Remove variable.
(__floorl): Do not force "inexact" exception.
C99 and C11 allow but do not require ceil, floor, round and trunc to
raise the "inexact" exception for noninteger arguments. TS 18661-1
requires that this exception not be raised by these functions. This
aligns them with general IEEE semantics, where "inexact" is only
raised if the final step of rounding the infinite-precision result to
the result type is inexact; for these functions, the
infinite-precision integer result is always representable in the
result type, so "inexact" should never be raised.
The generic implementations of ceil, floor and round functions contain
code to force "inexact" to be raised. This patch removes it for ceil
functions to align them with TS 18661-1 in this regard. Note that
some architecture-specific versions may still raise "inexact", so the
tests are not updated and the bug is not yet fixed.
Tested for x86_64, x86 and mips64.
[BZ #15479]
* sysdeps/ieee754/dbl-64/s_ceil.c: Do not mention "inexact"
exception in comment.
(huge): Remove variable.
(__ceil): Do not force "inexact" exception.
* sysdeps/ieee754/dbl-64/wordsize-64/s_ceil.c: Do not mention
"inexact" exception in comment.
(huge): Remove variable.
(__ceil): Do not force "inexact" exception.
* sysdeps/ieee754/flt-32/s_ceilf.c (huge): Remove variable.
(__ceilf): Do not force "inexact" exception.
* sysdeps/ieee754/ldbl-128/s_ceill.c: Do not mention "inexact"
exception in comment.
(huge): Remove variable.
(__ceill): Do not force "inexact" exception.
ldbl-128ibm had an implementation of fmal that just did (x * y) + z in
most cases, with no attempt at actually being a fused operation.
This patch replaces it with a genuine fused operation. It is not
necessarily correctly rounding, but should produce a result at least
as accurate as the long double arithmetic operations in libgcc, which
I think is all that can reasonably be expected for such a non-IEEE
format where arithmetic is approximate rather than rounded according
to any particular rule for determining the exact result. Like the
libgcc arithmetic, it may produce spurious overflow and underflow
results, and it falls back to the libgcc multiplication in the case of
(finite, finite, zero).
This concludes the fixes for bug 13304; any subsequently found fma
issues should go in separate Bugzilla bugs. Various other pieces of
bug 13304 were fixed in past releases over the past several years.
Tested for powerpc.
[BZ #13304]
* sysdeps/ieee754/ldbl-128ibm/s_fmal.c: Include <fenv.h>,
<float.h>, <math_private.h> and <stdlib.h>.
(add_split): New function.
(mul_split): Likewise.
(ext_val): New typedef.
(store_ext_val): New function.
(mul_ext_val): New function.
(compare): New function.
(add_split_ext): New function.
(__fmal): After checking for Inf, NaN and zero, compute result as
an exact sum of scaled double values in round-to-nearest before
adding those up and adjusting for other rounding modes.
* math/auto-libm-test-in: Remove xfail-rounding:ldbl-128ibm from
tests of fma.
* math/auto-libm-test-out: Regenerated.
When the signs differ, the precision of the conversion sometimes
drops below 106 bits. This strategy is identical to the
hexadecimal variant.
I've refactored tst-sprintf3 to enable testing a value with more
than 30 significant digits in order to demonstrate this failure
and its solution.
Additionally, this implicitly fixes a typo in the shift
quantities when subtracting from the high mantissa to compute
the difference.
The ldbl-128ibm implementation of nearbyintl uses logic that only
works in round-to-nearest mode. This contrasts with rintl, which
works in all rounding modes.
Now, arguably nearbyintl could simply be aliased to rintl, given that
spurious "inexact" is generally allowed for ldbl-128ibm, even for the
underlying arithmetic operations. But given that the only point of
nearbyintl is to avoid "inexact", this patch follows the more
conservative approach of adding conditionals to the rintl
implementation to make it suitable for use to implement nearbyintl,
then builds it for nearbyintl with USE_AS_NEARBYINTL defined. The
test test-nearbyint-except-2 shows up issues when traps on "inexact"
are enabled, which turn out to be problems with the powerpc
fenv_private.h implementation (two functions that should disable
exception traps potentially failing to do so in some cases); this
patch duly fixes that as well (I don't see any other existing cases
where this would be user-visible; there isn't much use of *_NOEX,
*hold* etc. in libm that requires exceptions to be discarded and not
trapped on).
Tested for powerpc.
[BZ #19790]
* sysdeps/ieee754/ldbl-128ibm/s_rintl.c [USE_AS_NEARBYINTL]
(rintl): Define as macro.
[USE_AS_NEARBYINTL] (__rintl): Likewise.
(__rintl) [USE_AS_NEARBYINTL]: Use SET_RESTORE_ROUND_NOEX instead
of fesetround. Ensure results are evaluated before end of scope.
* sysdeps/ieee754/ldbl-128ibm/s_nearbyintl.c: Define
USE_AS_NEARBYINTL and include s_rintl.c.
* sysdeps/powerpc/fpu/fenv_private.h (libc_feholdsetround_ppc):
Disable exception traps in new environment.
(libc_feholdsetround_ppc_ctx): Likewise.
The ldbl-128ibm implementation of remainderl has logic resulting in
incorrect tests for equality of the absolute values of the arguments
in the case of zero low parts. If the low parts are both zero but
with different signs, this can wrongly cause equal arguments to be
treated as different, resulting in turn in incorrect signs of zero
result in nondefault rounding modes arising from the subtractions done
when the arguments are not equal.
This patch fixes the logic to convert -0 low parts into +0 before the
comparison (remquo already has separate logic to deal with signs of
zero results, so doesn't need such a change). Tests are added for
remainderl and remquol similar to that for fmodl, and based on a
refactoring of it, since the bug depends on low parts which should not
be relied upon in tests not setting the representation explicitly
(although in fact the bug shows up in test-ldouble with current GCC).
Tested for powerpc.
[BZ #19677]
* sysdeps/ieee754/ldbl-128ibm/e_remainderl.c
(__ieee754_remainderl): Put zero low parts in canonical form.
* sysdeps/ieee754/ldbl-128ibm/test-fmodrem-ldbl-128ibm.c: New
file. Based on
sysdeps/ieee754/ldbl-128ibm/test-fmodl-ldbl-128ibm.c.
* sysdeps/ieee754/ldbl-128ibm/test-fmodl-ldbl-128ibm.c: Replace
with wrapper round test-fmodrem-ldbl-128ibm.c.
* sysdeps/ieee754/ldbl-128ibm/test-remainderl-ldbl-128ibm.c: New
file.
* sysdeps/ieee754/ldbl-128ibm/test-remquol-ldbl-128ibm.c:
Likewise.
* sysdeps/ieee754/ldbl-128ibm/Makefile (tests): Add
test-remainderl-ldbl-128ibm and test-remquol-ldbl-128ibm.
The ldbl-128ibm implementation of nextafterl / nexttowardl returns -0
in FE_DOWNWARD mode when taking the next value below the least
positive subnormal, when it should return +0. This patch fixes it to
check explicitly for this case.
Tested for powerpc.
[BZ #19678]
* sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c (__nextafterl):
Ensure +0.0 is returned when taking the next value below the least
positive value.
The ldbl-128ibm implementation of powl has some problems in the case
of overflow or underflow, which are mainly visible in non-default
rounding modes.
* When overflow or underflow is detected early, the correct sign of an
overflowing or underflowing result is not allowed for. This is
mostly hidden in the default rounding mode by the errno-setting
wrappers recomputing the result (except in non-default
error-handling modes such as -lieee), but visible in other rounding
modes where a result that is not zero or infinity causes the
wrappers not to do the recomputation.
* The final scaling is done before the sign is incorporated in the
result, but should be done afterwards for correct overflowing and
underflowing results in directed rounding modes.
This patch fixes those problems. Tested for powerpc.
[BZ #19674]
* sysdeps/ieee754/ldbl-128ibm/e_powl.c (__ieee754_powl): Include
sign in overflowing and underflowing results when overflow or
underflow is detected early. Include sign in result before rather
than after scaling.
The ldbl-128ibm implementations of remainderl and remquol have logic
resulting in incorrect tests for equality of the absolute values of
the arguments. Equality is tested based on the integer
representations of the high and low parts, with the sign bit masked
off the high part - but when this changes the sign of the high part,
the sign of the low part needs to be changed as well, and failure to
do this means arguments are wrongly treated as equal when they are
not.
This patch fixes the logic to adjust signs of low parts as needed.
Tested for powerpc.
[BZ #19603]
* sysdeps/ieee754/ldbl-128ibm/e_remainderl.c
(__ieee754_remainderl): Adjust sign of integer version of low part
when taking absolute value of high part.
* sysdeps/ieee754/ldbl-128ibm/s_remquol.c (__remquol): Likewise.
* math/libm-test.inc (remainder_test_data): Add another test.
(remquo_test_data): Likewise.
The ldbl-128ibm implementation of fmodl has logic to detect when the
first argument has absolute value less than or equal to the second.
This logic is only correct for nonzero low parts; if the high parts
are equal and the low parts are zero, then the signs of the low parts
(which have no semantic effect on the value of the long double number)
can result in equal values being wrongly treated as unequal, and an
incorrect result being returned from fmodl. This patch fixes this by
checking for the case of zero low parts.
Although this does show up in tests from libm-test.inc (both tests of
fmodl, and, indirectly, of remainderl / dreml), the dependence on
non-semantic zero low parts means that test shouldn't be expected to
reproduce it reliably; thus, this patch adds a standalone test that
sets up affected values using unions.
Tested for powerpc.
[BZ #19602]
* sysdeps/ieee754/ldbl-128ibm/e_fmodl.c (__ieee754_fmodl): Handle
equal high parts and both low parts zero specially.
* sysdeps/ieee754/ldbl-128ibm/test-fmodl-ldbl-128ibm.c: New test.
* sysdeps/ieee754/ldbl-128ibm/Makefile [$(subdir) = math] (tests):
Add test-fmodl-ldbl-128ibm.
The ldbl-128ibm implementation of fmodl has completely bogus logic for
subnormal results (in this context, that means results for which the
result is in the subnormal range for double, not results with absolute
value below LDBL_MIN), based on code used for ldbl-128 that is correct
in that case but incorrect in the ldbl-128ibm use. This patch fixes
it to convert the mantissa into the correct form expected by
ldbl_insert_mantissa, removing the other cases of the code that were
incorrect and in one case unreachable for ldbl-128ibm. A correct
exponent value is then passed to ldbl_insert_mantissa to reflect the
shifted result.
Tested for powerpc.
[BZ #19595]
* sysdeps/ieee754/ldbl-128ibm/e_fmodl.c (__ieee754_fmodl): Use
common logic for all cases of shifting subnormal results. Do not
insert sign bit in shifted mantissa. Always pass -1023 as biased
exponent to ldbl_insert_mantissa in subnormal case.
The ldbl-128ibm implementation of roundl is only correct in
round-to-nearest mode (in other modes, there are incorrect results and
overflow exceptions in some cases). This patch reimplements it along
the lines used for floorl, ceill and truncl, using __round on the high
part, and on the low part if the high part is an integer, and then
adjusting in the cases where this is incorrect.
Tested for powerpc.
[BZ #19594]
* sysdeps/ieee754/ldbl-128ibm/s_roundl.c (__roundl): Use __round
on high and low parts then adjust result and use
ldbl_canonicalize_int if needed.
The ldbl-128ibm implementation of truncl is only correct in
round-to-nearest mode (in other modes, there are incorrect results and
overflow exceptions in some cases). It is also unnecessarily
complicated, rounding both high and low parts to the nearest integer
and then adjusting for the semantics of trunc, when it seems more
natural to take the truncation of the high part (__trunc optimized
inline versions can be used), and the floor or ceiling of the low part
(depending on the sign of the high part) if the high part is an
integer, as was done for floorl and ceill. This patch makes it use
that simpler approach.
Tested for powerpc.
[BZ #19593]
* sysdeps/ieee754/ldbl-128ibm/s_truncl.c (__truncl): Use __trunc
on high part and __floor or __ceil on low part then use
ldbl_canonicalize_int if needed.
The ldbl-128ibm implementation of ceill is only correct in
round-to-nearest mode (in other modes, there are incorrect results and
overflow exceptions in some cases). It is also unnecessarily
complicated, rounding both high and low parts to the nearest integer
and then adjusting for the semantics of ceil, when it seems more
natural to take the ceiling of the high part (__ceil optimized inline
versions can be used), and that of the low part if the high part is an
integer, as was done for floorl. This patch makes it use that simpler
approach.
Tested for powerpc.
[BZ #19592]
* sysdeps/ieee754/ldbl-128ibm/s_ceill.c (__ceill): Use __ceil on
high and low parts then use ldbl_canonicalize_int if needed.
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.
The changes to restrict implementation-namespace symbol aliases such
as __finitel to compat symbols used code for __finitel in libm
analogous to that for __finitel in libc. However, the versions for
the two symbols are actually different, GLIBC_2.0 in libc and
GLIBC_2.1 in libm. This patch fixes the handling of the libm compat
symbol.
Tested for mips (o32), where it fixes an ABI test failure.
* sysdeps/ieee754/dbl-64/s_finite.c
[NO_LONG_DOUBLE && LDBL_CLASSIFY_COMPAT] (__finitel): Define
compat symbol at version GLIBC_2_1 and use GLIBC_2_1 in
SHLIB_COMPAT condition for libm, not GLIBC_2_0.
* sysdeps/ieee754/dbl-64/wordsize-64/s_finite.c
[NO_LONG_DOUBLE && LDBL_CLASSIFY_COMPAT] (__finitel): Likewise.
I get some math test-failures on s390 for float/double/ldouble for
various lrint/lround functions like:
lrint (0x1p64): Exception "Inexact" set
lrint (-0x1p64): Exception "Inexact" set
lround (0x1p64): Exception "Inexact" set
lround (-0x1p64): Exception "Inexact" set
...
GCC emits "convert to fixed" instructions for casting floating point
values to integer values. These instructions raise invalid and inexact
exceptions if the floating point value exceeds the integer type ranges.
This patch enables the various FIX_DBL_LONG_CONVERT_OVERFLOW macros in
order to avoid a cast from floating point to integer type and raise the
invalid exception with feraiseexcept.
The ldbl-128 rint/round functions are now using the same logic.
ChangeLog:
[BZ #19486]
* sysdeps/s390/fix-fp-int-convert-overflow.h: New File.
* sysdeps/generic/fix-fp-int-convert-overflow.h
(FIX_LDBL_LONG_CONVERT_OVERFLOW,
FIX_LDBL_LLONG_CONVERT_OVERFLOW): New define.
* sysdeps/arm/fix-fp-int-convert-overflow.h: Likewise.
* sysdeps/mips/mips32/fpu/fix-fp-int-convert-overflow.h:
Likewise.
* sysdeps/ieee754/ldbl-128/s_lrintl.c (__lrintl):
Avoid conversions to long int where inexact exceptions
could be raised.
* sysdeps/ieee754/ldbl-128/s_lroundl.c (__lroundl):
Likewise.
* sysdeps/ieee754/ldbl-128/s_llrintl.c (__llrintl):
Avoid conversions to long long int where inexact exceptions
could be raised.
* sysdeps/ieee754/ldbl-128/s_llroundl.c (__llroundl):
Likewise.
When looking at the code generated for pow() on ppc64 I noticed quite
a few sign extensions. Making the array indices unsigned reduces the
number of sign extensions from 24 to 7.
Tested for powerpc64le and x86_64.
Like the previous change, exploit the fact that computation for sin
and cos is identical except that it is apart by a quadrant. Also
remove csloww, csloww1 and csloww2 since they can easily be expressed
in terms of sloww, sloww1 and sloww2.
The sin and cos computation for this range of input is identical
except for a difference in quadrants by 1. Exploit that fact and the
common argument reduction to reduce computations for sincos.
Range reduction needs to be done only once for sin and cos, so copy
over all of the relevant functions (__sin, __cos, reduce_and_compute)
and consolidate common code.
The ldbl-128ibm implementation of logl is inaccurate for arguments
near 1, because when deciding whether to bypass a series expansion for
log(1+z), where z = x-1, it compares the square of z rather than z
itself with an epsilon value. This patch fixes that comparison, so
eliminating the test failures for inaccuracy of logl in such cases.
Tested for powerpc.
[BZ #19351]
* sysdeps/ieee754/ldbl-128ibm/e_logl.c (__ieee754_logl): When
expanding log(1+z), compare z rather than its square with epsilon
to determine when to avoid evaluating the expansion.
The ldbl-128ibm implementation of sinhl uses a slightly too small
overflow threshold (similar to bug 16407 for coshl). This patch fixes
it to use a safe threshold (so that values whose high part is above
the value compared with definitely result in an overflow in all
rounding modes).
Tested for powerpc.
[BZ #19350]
* sysdeps/ieee754/ldbl-128ibm/e_sinhl.c (__ieee754_sinhl):
Increase overflow threshold.
The ldbl-128ibm implementation of tanhl is inaccurate for small
arguments, because it returns x*(1+x) (maybe in an attempt to raise
"inexact") when x itself would be the accurate return value but
multiplying by 1+x introduces large errors. This patch fixes it to
return x in that case (when the mathematical result is x plus a
negligible remainder on the order of x^3) to avoid those errors.
Tested for powerpc.
[BZ #19349]
* sysdeps/ieee754/ldbl-128ibm/s_tanhl.c (__tanhl): Return argument
when small.
If a platform does not define "long-double-fcts = yes" in its
Makefiles and it does define __NO_LONG_DOUBLE_MATH in its installed
headers, it will currently create exported symbols for __finitel,
__isinfl, and __isnanl that can't be reached from userspace by
correct use of the finite(), isinf(), or isnan() macros in <math.h>.
To avoid this situation, by default for such platforms we now no
longer export these symbols, thus causing appropriate link-time
errors. However, for platforms that previously exported these
symbols, we continue to do so as compat symbols; this is enabled
by adding LDBL_CLASSIFY_COMPAT to math_private.h for the platform.
For tile, remove the now-unnecessary exports of those functions from
libc and libm.
Various sysdeps/ieee754/dbl-64 functions use double constants defined
using a union between a double and two ints, with separate big-endian
and little-endian definitions of the constants.
With modern C, this is unnecessary complication; hex float constants
(or __builtin_inf etc.) suffice to specify the exact value desired,
and so can avoid separate versions for each endianness. Having this
complication also complicates cleanups such as removing slow paths
from these library functions, as they need to make sure to remove both
copies of variables that are no longer used after such a cleanup (and
in at least one case, proper removal of a slow path will also involve
removing slow-path-only values from the middle of an array - an array
with both big-endian and little-endian copies - and adjusting other
references to that array).
So it makes sense to clean up the code to define these constants using
hex floats and so eliminate the endianness conditional. This patch
does so in the case of sqrt, where the two constants are such that it
makes sense just to put them directly in the code using them and
eliminate the names for them altogether.
Tested for arm (the code generated for sqrt does change, though not in
any significant way).
* sysdeps/ieee754/dbl-64/e_sqrt.c: Do not include uroot.h.
(__ieee754_sqrt): Use hex float constants instead of tm256.x and
t512.x.
* sysdeps/ieee754/dbl-64/uroot.h: Remove file.
The nan* functions handle their string argument by constructing a
NAN(...) string on the stack as a VLA and passing it to strtod
functions.
This approach has problems discussed in bug 16961 and bug 16962: the
stack usage is unbounded, and it gives incorrect results in certain
cases where the argument is not a valid n-char-sequence.
The natural fix for both issues is to refactor the NaN payload parsing
out of strtod into a separate function that the nan* functions can
call directly, so that no temporary string needs constructing on the
stack at all. This patch does that refactoring in preparation for
fixing those bugs (but without actually using the new functions from
nan* - which will also require exporting them from libc at version
GLIBC_PRIVATE). This patch is not intended to change any user-visible
behavior, so no tests are added (fixes for the above bugs will of
course add tests for them).
This patch builds on my recent fixes for strtol and strtod issues in
Turkish locales. Given those fixes, the parsing of NaN payloads is
locale-independent; thus, the new functions do not need to take a
locale_t argument.
Tested for x86_64, x86, mips64 and powerpc.
* stdlib/strtod_nan.c: New file.
* stdlib/strtod_nan_double.h: Likewise.
* stdlib/strtod_nan_float.h: Likewise.
* stdlib/strtod_nan_main.c: Likewise.
* stdlib/strtod_nan_narrow.h: Likewise.
* stdlib/strtod_nan_wide.h: Likewise.
* stdlib/strtof_nan.c: Likewise.
* stdlib/strtold_nan.c: Likewise.
* sysdeps/ieee754/ldbl-128/strtod_nan_ldouble.h: Likewise.
* sysdeps/ieee754/ldbl-128ibm/strtod_nan_ldouble.h: Likewise.
* sysdeps/ieee754/ldbl-96/strtod_nan_ldouble.h: Likewise.
* wcsmbs/wcstod_nan.c: Likewise.
* wcsmbs/wcstof_nan.c: Likewise.
* wcsmbs/wcstold_nan.c: Likewise.
* stdlib/Makefile (routines): Add strtof_nan, strtod_nan and
strtold_nan.
* wcsmbs/Makefile (routines): Add wcstod_nan, wcstold_nan and
wcstof_nan.
* include/stdlib.h (__strtof_nan): Declare and use
libc_hidden_proto.
(__strtod_nan): Likewise.
(__strtold_nan): Likewise.
(__wcstof_nan): Likewise.
(__wcstod_nan): Likewise.
(__wcstold_nan): Likewise.
* include/wchar.h (____wcstoull_l_internal): Declare.
* stdlib/strtod_l.c: Do not include <ieee754.h>.
(____strtoull_l_internal): Remove declaration.
(STRTOF_NAN): Define macro.
(SET_MANTISSA): Remove macro.
(STRTOULL): Likewise.
(____STRTOF_INTERNAL): Use STRTOF_NAN to parse NaN payload.
* stdlib/strtof_l.c (____strtoull_l_internal): Remove declaration.
(STRTOF_NAN): Define macro.
(SET_MANTISSA): Remove macro.
* sysdeps/ieee754/ldbl-128/strtold_l.c (STRTOF_NAN): Define macro.
(SET_MANTISSA): Remove macro.
* sysdeps/ieee754/ldbl-128ibm/strtold_l.c (STRTOF_NAN): Define
macro.
(SET_MANTISSA): Remove macro.
* sysdeps/ieee754/ldbl-64-128/strtold_l.c (STRTOF_NAN): Define
macro.
(SET_MANTISSA): Remove macro.
* sysdeps/ieee754/ldbl-96/strtold_l.c (STRTOF_NAN): Define macro.
(SET_MANTISSA): Remove macro.
* wcsmbs/wcstod_l.c (____wcstoull_l_internal): Remove declaration.
* wcsmbs/wcstof_l.c (____wcstoull_l_internal): Likewise.
* wcsmbs/wcstold_l.c (____wcstoull_l_internal): Likewise.
The lgamma (and likewise lgammaf, lgammal) function wrongly sets the
signgam variable even when building for strict ISO C conformance
(-std=c99 / -std=c11), although the user may define such a variable
and it's only in the implementation namespace for POSIX with XSI
extensions enabled.
Following discussions starting at
<https://sourceware.org/ml/libc-alpha/2013-04/msg00767.html> and
<https://sourceware.org/ml/libc-alpha/2015-10/msg00844.html>, it seems
that the safest approach for fixing this particular issue is for
signgam to become a weak alias for a newly exported symbol __signgam,
with the library functions only setting __signgam, at which point
static linker magic will preserve the alias for newly linked binaries
that refer to the library's signgam rather than defining their own,
while breaking the alias for programs that define their own signgam,
with new symbol versions for lgamma functions and with compat symbols
for existing binaries that set both signgam and __signgam.
This patch implements that approach for the fix. signgam is made into
a weak alias. The four symbols __signgam, lgamma, lgammaf, lgammal
get new symbol versions at version GLIBC_2.23, with the existing
versions of lgamma, lgammaf and lgammal becoming compat symbols.
When the compat versions are built, gamma, gammaf and gammal are
aliases for the compat versions (i.e. always set signgam); this is OK
as they are not ISO C functions, and avoids adding new symbol versions
for them unnecessarily. When the compat versions are not built
(i.e. for static linking and for future glibc ports), gamma, gammaf
and gammal are aliases for the new versions that set __signgam. The
ldbl-opt versions are updated accordingly.
The lgamma wrappers are adjusted so that the same source files,
included from different files with different definitions of
USE_AS_COMPAT, can build either the new versions or the compat
versions. Similar changes are made to the ia64 versions (untested).
Tests are added that the lgamma functions do not interfere with a user
variable called signgam for ISO C, with various choices for the size
of that variable, whether it is initialized, and for static and
dynamic linking. The conformtest whitelist entry is removed as well.
Tested for x86_64, x86, mips64 and powerpc, including looking at
objdump --dynamic-syms output to make sure the expected sets of
symbols were aliases. Also spot-tested that a binary built with old
glibc works properly (i.e. gets signgam set) when run with new glibc.
[BZ #15421]
* sysdeps/ieee754/s_signgam.c (signgam): Rename to __signgam,
initialize with 0 and define as weak alias of __signgam.
* include/math.h [!_ISOMAC] (__signgam): Declare.
* math/Makefile (libm-calls): Add w_lgamma_compat.
(tests): Add test-signgam-uchar, test-signgam-uchar-init,
test-signgam-uint, test-signgam-uint-init, test-signgam-ullong and
test-signgam-ullong-init.
(tests-static): Add test-signgam-uchar-static,
test-signgam-uchar-init-static, test-signgam-uint-static,
test-signgam-uint-init-static, test-signgam-ullong-static and
test-signgam-ullong-init-static.
(CFLAGS-test-signgam-uchar.c): New variable.
(CFLAGS-test-signgam-uchar-init.c): Likewise.
(CFLAGS-test-signgam-uchar-static.c): Likewise.
(CFLAGS-test-signgam-uchar-init-static.c): Likewise.
(CFLAGS-test-signgam-uint.c): Likewise.
(CFLAGS-test-signgam-uint-init.c): Likewise.
(CFLAGS-test-signgam-uint-static.c): Likewise.
(CFLAGS-test-signgam-uint-init-static.c): Likewise.
(CFLAGS-test-signgam-ullong.c): Likewise.
(CFLAGS-test-signgam-ullong-init.c): Likewise.
(CFLAGS-test-signgam-ullong-static.c): Likewise.
(CFLAGS-test-signgam-ullong-init-static.c): Likewise.
* math/Versions (libm): Add GLIBC_2.23.
* math/lgamma-compat.h: New file.
* math/test-signgam-main.c: Likewise.
* math/test-signgam-uchar-init-static.c: Likewise.
* math/test-signgam-uchar-init.c: Likewise.
* math/test-signgam-uchar-static.c: Likewise.
* math/test-signgam-uchar.c: Likewise.
* math/test-signgam-uint-init-static.c: Likewise.
* math/test-signgam-uint-init.c: Likewise.
* math/test-signgam-uint-static.c: Likewise.
* math/test-signgam-uint.c: Likewise.
* math/test-signgam-ullong-init-static.c: Likewise.
* math/test-signgam-ullong-init.c: Likewise.
* math/test-signgam-ullong-static.c: Likewise.
* math/test-signgam-ullong.c: Likewise.
* math/w_lgamma.c: Rename to w_lgamma_main.c and replace by
wrapper of w_lgamma_main.c.
* math/w_lgamma_compat.c: New file.
* math/w_lgamma_compatf.c: Likewise.
* math/w_lgamma_compatl.c: Likewise.
* math/w_lgamma_main.c: New file. Based on w_lgamma.c. Include
<lgamma-compat.h>. Condition contents on [BUILD_LGAMMA]. Support
defining compatibility symbols.
(__lgamma): Change to LGFUNC (__lgamma). Use CALL_LGAMMA.
* math/w_lgammaf.c: Rename to w_lgammaf_main.c and replace by
wrapper of w_lgammaf_main.c.
* math/w_lgammaf_main.c: New file. Based on w_lgammaf.c. Include
<lgamma-compat.h>. Condition contents on [BUILD_LGAMMA]. Support
defining compatibility symbols.
(__lgammaf): Change to LGFUNC (__lgammaf). Use CALL_LGAMMA.
* math/w_lgammal.c: Rename to w_lgammal_main.c and replace by
wrapper of w_lgammal_main.c.
* math/w_lgammal_main.c: New file. Based on w_lgammal.c. Include
<lgamma-compat.h>. Condition contents on [BUILD_LGAMMA]. Support
defining compatibility symbols.
(__lgammal): Change to LGFUNC (__lgammal). Use CALL_LGAMMA.
* sysdeps/ia64/fpu/lgamma-compat.h: New file.
* sysdeps/ia64/fpu/w_lgamma.c: Move to ....
* sysdeps/ia64/fpu/w_lgamma_main.c: ...here. Include
<lgamma-compat.h>.
(__ieee754_lgamma): Change to LGFUNC (lgamma). Use CALL_LGAMMA.
(__ieee754_gamma): Define as alias.
* sysdeps/ia64/fpu/w_lgammaf.c: Move to ....
* sysdeps/ia64/fpu/w_lgammaf_main.c: ...here. Include
<lgamma-compat.h>.
(__ieee754_lgammaf): Change to LGFUNC (lgammaf). Use CALL_LGAMMA.
(__ieee754_gammaf): Define as alias.
* sysdeps/ia64/fpu/w_lgammal.c: Move to ....
* sysdeps/ia64/fpu/w_lgammal_main.c: ...here. Include
<lgamma-compat.h>.
(__ieee754_lgammal): Change to LGFUNC (lgammal). Use CALL_LGAMMA.
(__ieee754_gammal): Define as alias.
* sysdeps/ieee754/ldbl-opt/w_lgamma.c: Move to ....
* sysdeps/ieee754/ldbl-opt/w_lgamma_compat.c: ...here. Include
<math/w_lgamma_compat.c>.
[LONG_DOUBLE_COMPAT(libm, GLIBC_2_0)] (__lgammal_dbl_compat):
Define as alias of __lgamma_compat and use in defining lgammal.
* sysdeps/ieee754/ldbl-opt/w_lgammal.c: Move to ....
* sysdeps/ieee754/ldbl-opt/w_lgamma_compatl.c: ...here. Include
<math/lgamma-compat.h> and <math/w_lgamma_compatl.c>.
(USE_AS_COMPAT): New macro.
(LGAMMA_OLD_VER): Undefine and redefine.
(lgammal): Do not define here.
(gammal): Only define here if [GAMMA_ALIAS].
* conform/linknamespace.pl (@whitelist): Remove signgam.
* sysdeps/nacl/libm.abilist: Update.
* sysdeps/unix/sysv/linux/aarch64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/alpha/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/arm/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/hppa/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/i386/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/ia64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/coldfire/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/m680x0/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/microblaze/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/nios2/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm-le.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sh/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/tile/tilepro/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Likewise.
Kind of hokey, but errno.h drags in misc/sys/param.h which
defines MIN/MAX causing an error. Include system headers
first to grab MIN/MAX definition in param.h, and define
HAVE_ALLOCA to preserve existing behavior.
* sysdeps/ieee754/ldbl-128ibm/mpn2ldl.c: Include gmp headers
after system headers to prevent MIN/MAX redefinition. Define
HAVE_ALLOCA to preserve builtin alloca usage.
Include the __sin and __cos functions as local static copies to allow
deper optimization of the functions. This change shows an improvement
of about 17% in the min case and 12.5% in the mean case for the sincos
microbenchmark on x86_64.
* sysdeps/ieee754/dbl-64/s_sin.c (__sin)[IN_SINCOS]: Mark function
static and don't set or restore rounding.
(__cos)[IN_SINCOS]: Likewise.
* sysdeps/ieee754/dbl-64/s_sincos.c: Include s_sin.c.
(__sincos): Set and restore rounding mode. Remove check for infinite
or NaN input.
For ldbl-128ibm, if the result of strtold overflows in the final
conversion from MPN to IBM long double (because the exponent for a
106-bit IEEE result is 1023 but the high part would end up as
0x1p1024, which overflows), that conversion code fails to handle this
and produces an invalid long double value (high part infinite, low
part not zero) without raising exceptions or setting errno. This
patch adds an explicit check for this case to ensure an appropriate
result is returned in a way that ensures the right exceptions are
raised, with errno set.
Tested for powerpc.
[BZ #14551]
* sysdeps/ieee754/ldbl-128ibm/mpn2ldbl.c: Include <errno.h>.
(__mpn_construct_long_double): If high part overflows to infinity,
set errno and recompute overflowed result of the correct sign.
* sysdeps/ieee754/ldbl-128ibm/Makefile
[$(subdir) = stdlib] (tests): Add tst-strtold-ldbl-128ibm.
[$(subdir) = stdlib] ($(objpfx)tst-strtold-ldbl-128ibm): Depend on
$(libm).
* sysdeps/ieee754/ldbl-128ibm/tst-strtold-ldbl-128ibm.c: New file.
For some large arguments, the dbl-64 implementation of remainder gives
zero results with the wrong sign, resulting from a subtraction that is
mathematically correct but does not guarantee that a zero result has
the sign of the first argument to remainder. This patch adds an
appropriate check for this case, similar to other implementations of
remainder in the case of equality, and adds tests of remainder on
inputs already used to test remquo.
Tested for x86_64 and x86.
[BZ #19201]
* sysdeps/ieee754/dbl-64/e_remainder.c (__ieee754_remainder):
Check for zero remainder in case of large exponents and ensure
correct sign of result in that case.
* math/libm-test.inc (remainder_test_data): Add more tests.
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.
The ldbl-128 version of log1pl raises a spurious "invalid" exception
for a -qNaN argument. This patch fixes this by making the initial
check for infinities and NaNs handle arguments of both signs in such a
way that NaNs result in a NaN being returned (quietly if the input NaN
was quiet) while +Inf results in +Inf being returned and -Inf results
in a qNaN being returned with "invalid" exception raised.
Tested for mips64.
[BZ #19189]
* sysdeps/ieee754/ldbl-128/s_log1pl.c (__log1pl): Make check for
non-finite argument handle arguments with negative sign.
The libm drem functions just call the corresponding __remainder
functions. This patch removes the unnecessary wrappers by making them
into weak aliases at the ELF level.
Tested for x86_64, x86, mips64 and powerpc.
[BZ #16171]
* math/w_remainder.c (drem): Define as weak alias of __remainder.
[NO_LONG_DOUBLE] (dreml): Define as weak alias of __remainder.
* math/w_remainderf.c (dremf): Define as weak alias of
__remainderf.
* math/w_remainderl.c (dreml): Define as weak alias of
__remainderl.
* sysdeps/ia64/fpu/e_remainder.S (drem): Define as weak alias of
__remainder.
* sysdeps/ia64/fpu/e_remainderf.S (dremf): Define as weak alias of
__remainderf.
* sysdeps/ia64/fpu/e_remainderl.S (dreml): Define as weak alias of
__remainderl.
* sysdeps/ieee754/ldbl-opt/nldbl-remainder.c (dreml): Define as
weak alias of remainderl.
* sysdeps/ieee754/ldbl-opt/w_remainder.c
[LONG_DOUBLE_COMPAT(libm, GLIBC_2_0)] (__drem): Define as strong
alias of __remainder.
[LONG_DOUBLE_COMPAT(libm, GLIBC_2_0)] (dreml): Use compat_symbol.
* sysdeps/ieee754/ldbl-opt/w_remainderl.c (__dreml): Define as
strong alias of __remainderl.
(dreml): Use long_double_symbol.
* math/Makefile (libm-calls): Remove w_drem.
* sysdeps/ieee754/ldbl-opt/Makefile (libnldbl-calls): Remove drem.
(CFLAGS-nldbl-drem.c): Remove variable.
(CFLAGS-nldbl-remainder.c): Add -fno-builtin-dreml.
* math/w_drem.c: Remove file.
* math/w_dremf.c: Likewise.
* math/w_dreml.c: Likewise.
* sysdeps/ieee754/ldbl-opt/nldbl-drem.c: Likewise.
* sysdeps/ieee754/ldbl-opt/w_drem.c: Likewise.
* sysdeps/ieee754/ldbl-opt/w_dreml.c: Likewise.
C11 defines standard <float.h> macros *_TRUE_MIN for the least
positive subnormal value of a type. Now that we build with
-std=gnu11, we can use these macros in glibc. This patch replaces
previous uses of the GCC predefines __*_DENORM_MIN__ (used in
<float.h> to define *_TRUE_MIN), as well as *_DENORM_MIN references in
comments.
Tested for x86_64 and x86 (testsuite, and that installed shared
libraries are unchanged by the patch). Also tested for powerpc that
installed stripped shared libraries are unchanged by the patch.
* math/libm-test.inc (min_subnorm_value): Use LDBL_TRUE_MIN,
DBL_TRUE_MIN and FLT_TRUE_MIN instead of __LDBL_DENORM_MIN__,
__DBL_DENORM_MIN__ and __FLT_DENORM_MIN__.
* sysdeps/ieee754/dbl-64/s_fma.c (__fma): Refer to DBL_TRUE_MIN
instead of DBL_DENORM_MIN in comment.
* sysdeps/ieee754/ldbl-128/s_fmal.c (__fmal): Refer to
LDBL_TRUE_MIN instead of LDBL_DENORM_MIN in comment.
* sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c: Include <float.h>.
(__nextafterl): Use LDBL_TRUE_MIN instead of __LDBL_DENORM_MIN__.
* sysdeps/ieee754/ldbl-96/s_fmal.c (__fmal): Refer to
LDBL_TRUE_MIN instead of LDBL_DENORM_MIN in comment.
One common case of __GNUC_PREREQ (4, 7) conditionals is use of
diagnostic control pragmas for -Wmaybe-uninitialized, an option
introduced in GCC 4.7 where older GCC needed -Wuninitialized to be
controlled instead if the warning appeared with older GCC. This patch
removes such conditionals.
(There remain several older uses of -Wno-uninitialized in makefiles
that still need to be converted to diagnostic control pragmas if the
issue is still present with current sources and supported GCC
versions, and it's likely that in most cases those pragmas also will
end up controlling -Wmaybe-uninitialized.)
Tested for x86_64 and x86 (testsuite, and that installed stripped
shared libraries are unchanged by the patch, except for libresolv
since res_send.c contains assertions whose line numbers are changed by
the patch).
* resolv/res_send.c (send_vc) [__GNUC_PREREQ (4, 7)]: Make code
unconditional.
* soft-fp/fmadf4.c [__GNUC_PREREQ (4, 7)]: Likewise.
[!__GNUC_PREREQ (4, 7)]: Remove conditional code.
* soft-fp/fmasf4.c [__GNUC_PREREQ (4, 7)]: Make code
unconditional.
[!__GNUC_PREREQ (4, 7)]: Remove conditional code.
* soft-fp/fmatf4.c [__GNUC_PREREQ (4, 7)]: Make code
unconditional.
[!__GNUC_PREREQ (4, 7)]: Remove conditional code.
* stdlib/setenv.c
[((__GNUC__ << 16) + __GNUC_MINOR__) >= ((4 << 16) + 7)]: Make
code unconditional.
[!(((__GNUC__ << 16) + __GNUC_MINOR__) >= ((4 << 16) + 7))]:
Remove conditional code.
* sysdeps/ieee754/dbl-64/e_lgamma_r.c
(__ieee754_lgamma_r) [__GNUC_PREREQ (4, 7)]: Make code
unconditional.
(__ieee754_lgamma_r) [!__GNUC_PREREQ (4, 7)]: Remove conditional
code.
* sysdeps/ieee754/flt-32/e_lgammaf_r.c
(__ieee754_lgammaf_r) [__GNUC_PREREQ (4, 7)]: Make code
unconditional.
(__ieee754_lgammaf_r) [!__GNUC_PREREQ (4, 7)]: Remove conditional
code.
* sysdeps/ieee754/ldbl-128/k_tanl.c
(__kernel_tanl) [__GNUC_PREREQ (4, 7)]: Make code unconditional.
(__kernel_tanl) [!__GNUC_PREREQ (4, 7)]: Remove conditional code.
* sysdeps/ieee754/ldbl-128ibm/k_tanl.c
(__kernel_tanl) [__GNUC_PREREQ (4, 7)]: Make code unconditional.
(__kernel_tanl) [!__GNUC_PREREQ (4, 7)]: Remove conditional code.
* sysdeps/ieee754/ldbl-96/e_lgammal_r.c
(__ieee754_lgammal_r) [__GNUC_PREREQ (4, 7)]: Make code
unconditional.
(__ieee754_lgammal_r) [!__GNUC_PREREQ (4, 7)]: Remove conditional
code.
* sysdeps/ieee754/ldbl-96/k_tanl.c
(__kernel_tanl) [__GNUC_PREREQ (4, 7)]: Make code unconditional.
(__kernel_tanl) [!__GNUC_PREREQ (4, 7)]: Remove conditional code.
j1 and jn can underflow for small arguments, but fail to set errno
when underflowing to 0. This patch fixes them to set errno in that
case.
Tested for x86_64, x86, mips64 and powerpc.
[BZ #18611]
* sysdeps/ieee754/dbl-64/e_j1.c (__ieee754_j1): Set errno and
avoid excess range and precision on underflow.
* sysdeps/ieee754/dbl-64/e_jn.c (__ieee754_jn): Likewise.
* sysdeps/ieee754/flt-32/e_j1f.c (__ieee754_j1f): Likewise.
* sysdeps/ieee754/flt-32/e_jnf.c (__ieee754_jnf): Likewise.
* sysdeps/ieee754/ldbl-128/e_j1l.c (__ieee754_j1l): Set errno on
underflow.
* sysdeps/ieee754/ldbl-128/e_jnl.c (__ieee754_jnl): Likewise.
* sysdeps/ieee754/ldbl-128ibm/e_jnl.c (__ieee754_jnl): Likewise.
* sysdeps/ieee754/ldbl-96/e_j1l.c (__ieee754_j1l): Likewise.
* sysdeps/ieee754/ldbl-96/e_jnl.c (__ieee754_jnl): Likewise.
* math/auto-libm-test-in: Do not allow missing errno setting for
tests of j1 and jn.
* math/auto-libm-test-out: Regenerated.
My recent addition of more tests for j0 showed up that the ldbl-128
implementation of j0l produces spurious underflow exceptions for
arguments close to 0 (when the result is very close to 1). This patch
fixes this by just returning the argument in that case.
Tested for mips64 (where it fixes the recently-added tests that were
previously failing).
[BZ #19156]
* sysdeps/ieee754/ldbl-128/e_j0l.c (__ieee754_j0l): Return 1 for
arguments very close to 0.
For 32-bit MIPS and some other systems, various of the lrint, llrint,
lround, llround functions can be missing exceptions on overflow
because casts do not (in current GCC) result in the proper
exceptions. In the MIPS case there are two problems here: MIPS I code
generation uses an assembler macro that doesn't raise exceptions,
while the libgcc conversions of floating-point values to long long
also do not raise "invalid" on all overflow cases (and can raise
spurious "inexact").
This patch adds support in the generic code (only the functions for
which this problem has actually been seen) for forcing the "invalid"
exception in the problem cases, and enables that support for the
affected MIPS cases.
Tested for MIPS; also tested for x86_64 and x86 that installed
stripped shared libraries are unchanged by this patch.
[BZ #16399]
* sysdeps/generic/fix-fp-int-convert-overflow.h: New file.
* sysdeps/ieee754/dbl-64/s_llrint.c: Include <fenv.h>, <limits.h>
and <fix-fp-int-convert-overflow.h>.
(__llrint) [FE_INVALID]: Force FE_INVALID exception as needed if
FIX_DBL_LLONG_CONVERT_OVERFLOW.
* sysdeps/ieee754/dbl-64/s_llround.c: Include <fenv.h>, <limits.h>
and <fix-fp-int-convert-overflow.h>.
(__llround) [FE_INVALID]: Force FE_INVALID exception as needed if
FIX_DBL_LLONG_CONVERT_OVERFLOW.
* sysdeps/ieee754/dbl-64/s_lrint.c: Include
<fix-fp-int-convert-overflow.h>.
(__lrint) [FE_INVALID]: Force FE_INVALID exception as needed if
FIX_DBL_LLONG_CONVERT_OVERFLOW.
* sysdeps/ieee754/dbl-64/s_lround.c: Include
<fix-fp-int-convert-overflow.h>.
(__lround) [FE_INVALID]: Force FE_INVALID exception as needed if
FIX_DBL_LLONG_CONVERT_OVERFLOW.
* sysdeps/ieee754/flt-32/s_llrintf.c: Include <fenv.h>, <limits.h>
and <fix-fp-int-convert-overflow.h>.
(__llrintf) [FE_INVALID]: Force FE_INVALID exception as needed if
FIX_DBL_LLONG_CONVERT_OVERFLOW.
* sysdeps/ieee754/flt-32/s_llroundf.c: Include <fenv.h>,
<limits.h> and <fix-fp-int-convert-overflow.h>.
(__llroundf) [FE_INVALID]: Force FE_INVALID exception as needed if
FIX_DBL_LLONG_CONVERT_OVERFLOW.
* sysdeps/ieee754/flt-32/s_lrintf.c: Include <fenv.h>, <limits.h>
and <fix-fp-int-convert-overflow.h>.
(__lrintf) [FE_INVALID]: Force FE_INVALID exception as needed if
FIX_DBL_LLONG_CONVERT_OVERFLOW.
* sysdeps/ieee754/flt-32/s_lroundf.c: Include <fenv.h>, <limits.h>
and <fix-fp-int-convert-overflow.h>.
(__lroundf) [FE_INVALID]: Force FE_INVALID exception as needed if
FIX_DBL_LLONG_CONVERT_OVERFLOW.
* sysdeps/mips/mips32/fpu/fix-fp-int-convert-overflow.h: New file.
The dbl-64 implementation of lrint produces incorrect results for some
arguments with 64-bit long because a 32-bit (unsigned) low part of the
mantissa is shifted left, losing high bits in the process. This patch
fixes this by casting to long int before shifting, as in lround (as
this case only applies for 64-bit long, there are no issues with
sign-extension).
Tested for mips64 (n64).
[BZ #19095]
* sysdeps/ieee754/dbl-64/s_lrint.c (__lrint): Cast low part of
mantissa to long int before shifting left.
The dbl-64, ldbl-96 and ldbl-128 implementations of lrint and llrint
fail to produce "invalid" exceptions in cases where the rounded result
overflows the target type, but truncating the floating-point argument
to the next integer towards zero does not overflow it (so in
particular casts do not produce such exceptions). (This issue cannot
arise for float, or for double with 64-bit target type, or for ldbl-96
with 64-bit target type and negative arguments, because of
insufficient precision in the floating-point type for arguments with
the relevant property to exist. It also obviously cannot arise in
FE_TOWARDZERO mode.)
This patch fixes these problems by inserting checks for the special
cases that can occur in each implementation, and explicitly raising
FE_INVALID (and avoiding the cast if it might raise spurious
FE_INEXACT, while raising FE_INEXACT explicitly in the cases where it
is needed; unlike lround and llround, FE_INEXACT is required, not
optional, for these functions for a within-range inexact result).
The fixes are conditional on FE_INVALID or FE_INEXACT being defined.
If any future architecture supports one but not both of those
exceptions, the code will fail to compile and need fixing to handle
that case (this seemed better than conditioning on both macros being
defined, resulting in code that would compile but quietly miss
exceptions on such a system).
Tested for x86_64, x86 and mips64. Tested the ldbl-96 changes (only
relevant for ia64, it appears) on x86_64 by removing the x86_64
versions of lrintl / llrintl.
[BZ #19094]
* sysdeps/ieee754/dbl-64/s_lrint.c: Include <fenv.h> and
<limits.h>.
(__lrint) [FE_INVALID || FE_INEXACT]: Force FE_INVALID exception
when result overflows but exception would not result from cast.
* sysdeps/ieee754/ldbl-128/s_llrintl.c: Include <fenv.h> and
<limits.h>.
(__llrintl) [FE_INVALID || FE_INEXACT]: Force FE_INVALID exception
when result overflows but exception would not result from cast.
* sysdeps/ieee754/ldbl-128/s_lrintl.c: Include <fenv.h> and
<limits.h>.
(__lrintl) [FE_INVALID || FE_INEXACT]: Force FE_INVALID exception
when result overflows but exception would not result from cast.
* sysdeps/ieee754/ldbl-96/s_llrintl.c: Include <fenv.h> and
<limits.h>.
(__llrintl) [FE_INVALID || FE_INEXACT]: Force FE_INVALID exception
when result overflows but exception would not result from cast.
* sysdeps/ieee754/ldbl-96/s_lrintl.c: Include <fenv.h> and
<limits.h>.
(__lrintl) [FE_INVALID || FE_INEXACT]: Force FE_INVALID exception
when result overflows but exception would not result from cast.
* math/libm-test.inc (lrint_test_data): Add more tests.
(llrint_test_data): Likewise.
The dbl-64, ldbl-96 and ldbl-128 implementations of lround and llround
fail to produce "invalid" exceptions in cases where the rounded result
overflows the target type, but truncating the floating-point argument
to the next integer towards zero does not overflow it (so in
particular casts do not produce such exceptions). (This issue cannot
arise for float, or for double with 64-bit target type, or for ldbl-96
with 64-bit target type and negative arguments, because of
insufficient precision in the floating-point type for arguments with
the relevant property to exist.)
This patch fixes these problems by inserting checks for the special
cases that can occur in each implementation, and explicitly raising
FE_INVALID (and avoiding the cast if it might raise spurious
FE_INEXACT).
Tested for x86_64, x86 and mips64.
[BZ #19088]
* sysdeps/ieee754/dbl-64/s_lround.c: Include <fenv.h> and
<limits.h>.
(__lround) [FE_INVALID]: Force FE_INVALID exception when result
overflows but exception would not result from cast.
* sysdeps/ieee754/dbl-64/wordsize-64/s_lround.c: Include <fenv.h>
and <limits.h>.
(__lround) [FE_INVALID]: Force FE_INVALID exception when result
overflows but exception would not result from cast.
* sysdeps/ieee754/ldbl-128/s_llroundl.c: Include <fenv.h> and
<limits.h>.
(__llroundl) [FE_INVALID]: Force FE_INVALID exception when result
overflows but exception would not result from cast.
* sysdeps/ieee754/ldbl-128/s_lroundl.c: Include <fenv.h> and
<limits.h>.
(__lroundl) [FE_INVALID]: Force FE_INVALID exception when result
overflows but exception would not result from cast.
* sysdeps/ieee754/ldbl-96/s_llroundl.c: Include <fenv.h> and
<limits.h>.
(__llroundl) [FE_INVALID]: Force FE_INVALID exception when result
overflows but exception would not result from cast.
* sysdeps/ieee754/ldbl-96/s_lroundl.c: Include <fenv.h> and
<limits.h>.
(__lroundl) [FE_INVALID]: Force FE_INVALID exception when result
overflows but exception would not result from cast.
* math/libm-test.inc (lround_test_data): Add more tests.
(llround_test_data): Likewise.
The ldbl-128 implementations of lrintl and lroundl miss "invalid"
exceptions on systems with 32-bit long for arguments that overflow
long but have exponent below 48. This patch fixes this by rearranging
the sequence of tests in the code so the exponent < 48 case is only
used for exponents that don't overflow long.
Tested for mips64 (n32 and n64).
[BZ #19085]
* sysdeps/ieee754/ldbl-128/s_lrintl.c (__lrintl): Move test for
exponent below 48 inside case for non-overflowing exponent.
* sysdeps/ieee754/ldbl-128/s_lroundl.c (__lroundl): Likewise.
This patch enables use of sysdeps/ieee754/dbl-64/wordsize-64 for
MIPS64 (both n64 and n32), removing a #error in one case now that case
has been tested and found to work.
Tested for mips64 (n64 and n32).
* sysdeps/mips/mips64/Implies: Use ieee754/dbl-64/wordsize-64.
* sysdeps/ieee754/dbl-64/wordsize-64/s_issignaling.c
(__issignaling) [HIGH_ORDER_BIT_IS_SET_FOR_SNAN]: Remove #error.
The implementation of lround in dbl-64/wordsize-64 as an alias or
wrapper for llround is always incorrect when long is not 64-bit,
because it misses required exceptions in overflow cases, as shown by
my recently added tests. This patch removes that alias / wrapper in
the non-LP64 case, together with the REGISTER_CAST_INT32_TO_INT64
macro, restoring the previous version of lround for dbl-64/wordsize-64
(newly conditioned on !_LP64).
Tested for x86_64, and for mips64 with use of dbl-64/wordsize-64
enabled.
[BZ #19079]
* sysdeps/ieee754/dbl-64/wordsize-64/s_lround.c: Restore previous
file, conditioned on [!_LP64].
* sysdeps/ieee754/dbl-64/wordsize-64/s_llround.c
[!_LP64] (__lround): Do not define as function or alias.
[!_LP64] (lround): Likewise.
[!_LP64] (__lroundl): Likewise.
[!_LP64] (lroundl): Likewise.
* sysdeps/tile/sysdep.h (REGISTER_CAST_INT32_TO_INT64): Remove
macro.
* sysdeps/x86_64/x32/sysdep.h (REGISTER_CAST_INT32_TO_INT64):
Likewise.
The ldbl-128ibm expl wrapper checks the argument to determine when to
call __kernel_standard_l, thereby overriding overflowing results from
__ieee754_expl that could otherwise (given appropriately patched
libgcc) be correct for the rounding mode. This patch changes it to
check the result of __ieee754_expl instead, as other versions of this
wrapper do.
Tested for powerpc.
[BZ #19078]
* sysdeps/ieee754/ldbl-128ibm/w_expl.c (o_thres): Remove variable.
(u_thres): Likewise.
(__expl): Determine whether to call __kernel_standard_l based on
value of result, not argument.
The ldbl-128ibm implementation of logl produces a zero with the wrong
sign for logl (1) in FE_DOWNWARD mode. This patch makes it explicitly
return 0.0L in that case, as in e.g. the ldbl-128 implementation.
Tested for powerpc.
[BZ #19077]
* sysdeps/ieee754/ldbl-128ibm/e_logl.c (__ieee754_logl): Return
0.0L for argument 1.0L.
The ldbl-128ibm implementation of log1pl produces an infinity with the
wrong sign for log1pl (-1) in FE_DOWNWARD mode. This patch fixes this
by changing a division (-1.0L / (x - x)) (incorrect in FE_DOWNWARD
mode) to (-1.0L / 0.0L) (correct in all rounding modes).
Tested for powerpc.
[BZ #19076]
* sysdeps/ieee754/ldbl-128ibm/s_log1pl.c (__log1pl): Divide by
constant 0.0L when computing infinite result.
The ldbl-96 version of lroundl is incorrect for systems with 64-bit
long when the argument's absolute value is just below a power of 2,
2^32 or more, and rounds up to the next integer; in such cases, it
returns 0. The problem is incrementing the high part of the mantissa
loses the high bit of the value (which is not an issue for any other
floating-point format, and is handled specially in lround when the bit
corresponding to 0.5 was in the high part rather than the low part).
This patch fixes this in a similar way to that used in llroundl:
storing the high part in an unsigned long variable before incrementing
it, so problems cannot occur in the case when this code is reachable.
I improved test coverage for both lround and llround by making them
use the same test inputs (appropriately conditioned on the size of
long in the lround case) - complete with the same comments, to make
comparison as easy as possible. (This test coverage improvement was
how I found the lroundl bug.)
Tested for x86_64 and x86.
[BZ #19071]
* sysdeps/ieee754/ldbl-96/s_lroundl.c (__lroundl): Use unsigned
long int variable to store possibly incremented high part of
mantissa.
* math/libm-test.inc (lround_test_data): Add tests used for
llround. Use [LONG_MAX > 0x7fffffff] consistently as condition
for tests requiring 64-bit long. Do not condition tests on
[TEST_FLOAT] unnecessarily.
(llround_test_data): Add tests used for lround. Add another
expectation for the "inexact" exception. Do not condition tests
on [TEST_FLOAT] unnecessarily.
On powerpc32 hard-float, older processors (ones where fcfid is not
available for 32-bit code), GCC generates conversions from integers to
floating point that wrongly convert integer 0 to -0 instead of +0 in
FE_DOWNWARD mode. This in turn results in logb and a few other
functions wrongly returning -0 when they should return +0.
This patch works around this issue in glibc as I proposed in
<https://sourceware.org/ml/libc-alpha/2015-09/msg00728.html>, so that
the affected functions can be correct and the affected tests pass in
the absence of a GCC fix for this longstanding issue (GCC bug 67771 -
if fixed, of course we can put in GCC version conditionals, and
eventually phase out the workarounds). A new macro
FIX_INT_FP_CONVERT_ZERO is added in a new sysdeps header
fix-int-fp-convert-zero.h, and the powerpc32/fpu version of that
header defines the macro based on the results of a configure test for
whether such conversions use the fcfid instruction.
Tested for x86_64 (that installed stripped shared libraries are
unchanged by the patch) and powerpc (that HAVE_PPC_FCFID comes out to
0 as expected and that the relevant tests are fixed). Also tested a
build with GCC configured for -mcpu=power4 and verified that
HAVE_PPC_FCFID comes out to 1 in that case.
There are still some other issues to fix to get test-float and
test-double passing cleanly for older powerpc32 processors (apart from
the need for an ulps regeneration for powerpc). (test-ldouble will be
harder to get passing cleanly, but with a combination of selected
fixes to ldbl-128ibm code that don't involve significant performance
issues, allowing spurious underflow and inexact exceptions for that
format, and lots of XFAILing for the default case of unpatched libgcc,
it should be doable.)
[BZ #887]
[BZ #19049]
[BZ #19050]
* sysdeps/generic/fix-int-fp-convert-zero.h: New file.
* sysdeps/ieee754/dbl-64/e_log10.c: Include
<fix-int-fp-convert-zero.h>.
(__ieee754_log10): Adjust signs as needed if FIX_INT_FP_CONVERT_ZERO.
* sysdeps/ieee754/dbl-64/e_log2.c: Include
<fix-int-fp-convert-zero.h>.
(__ieee754_log2): Adjust signs as needed if FIX_INT_FP_CONVERT_ZERO.
* sysdeps/ieee754/dbl-64/s_erf.c: Include
<fix-int-fp-convert-zero.h>.
(__erfc): Adjust signs as needed if FIX_INT_FP_CONVERT_ZERO.
* sysdeps/ieee754/dbl-64/s_logb.c: Include
<fix-int-fp-convert-zero.h>.
(__logb): Adjust signs as needed if FIX_INT_FP_CONVERT_ZERO.
* sysdeps/ieee754/flt-32/e_log10f.c: Include
<fix-int-fp-convert-zero.h>.
(__ieee754_log10f): Adjust signs as needed if FIX_INT_FP_CONVERT_ZERO.
* sysdeps/ieee754/flt-32/e_log2f.c: Include
<fix-int-fp-convert-zero.h>.
(__ieee754_log2f): Adjust signs as needed if FIX_INT_FP_CONVERT_ZERO.
* sysdeps/ieee754/flt-32/s_erff.c: Include
<fix-int-fp-convert-zero.h>.
(__erfcf): Adjust signs as needed if FIX_INT_FP_CONVERT_ZERO.
* sysdeps/ieee754/flt-32/s_logbf.c: Include
<fix-int-fp-convert-zero.h>.
(__logbf): Adjust signs as needed if FIX_INT_FP_CONVERT_ZERO.
* sysdeps/ieee754/ldbl-128ibm/s_erfl.c: Include
<fix-int-fp-convert-zero.h>.
(__erfcl): Adjust signs as needed if FIX_INT_FP_CONVERT_ZERO.
* sysdeps/ieee754/ldbl-128ibm/s_logbl.c: Include
<fix-int-fp-convert-zero.h>.
(__logbl): Adjust signs as needed if FIX_INT_FP_CONVERT_ZERO.
* sysdeps/powerpc/powerpc32/fpu/configure.ac: New file.
* sysdeps/powerpc/powerpc32/fpu/configure: New generated file.
* sysdeps/powerpc/powerpc32/fpu/fix-int-fp-convert-zero.h: New
file.
* config.h.in [_LIBC] (HAVE_PPC_FCFID): New macro.
ISO C requires overflowing results from nexttoward to be the
appropriate infinity independent of the rounding mode, but some
implementations use a rounding-mode-dependent result (this is the same
issue as was fixed for nextafter in bug 16677). This patch fixes the
problem by making the nexttoward implementations discard the result
from the floating-point computation that forced an overflow exception
and then return the infinity previously computed with integer
arithmetic.
Tested for x86_64, x86, mips64 and powerpc.
[BZ #19059]
* math/s_nexttowardf.c (__nexttowardf): Do not return value from
overflowing computation.
* sysdeps/i386/fpu/s_nexttoward.c (__nexttoward): Likewise.
* sysdeps/i386/fpu/s_nexttowardf.c (__nexttowardf): Likewise.
* sysdeps/ieee754/ldbl-128/s_nexttoward.c (__nexttoward):
Likewise.
* sysdeps/ieee754/ldbl-128/s_nexttowardf.c (__nexttowardf):
Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_nexttoward.c (__nexttoward):
Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_nexttowardf.c (__nexttowardf):
Likewise.
* sysdeps/ieee754/ldbl-96/s_nexttoward.c (__nexttoward): Likewise.
* sysdeps/ieee754/ldbl-96/s_nexttowardf.c (__nexttowardf):
Likewise.
* sysdeps/ieee754/ldbl-opt/s_nexttowardfd.c (__nldbl_nexttowardf):
Likewise.
* math/libm-test.inc (nexttoward_test_data): Add more tests.
The ldbl-128 / ldbl-128ibm implementation of lgamma has problems with
its handling of large arguments. It has an overflow threshold that is
correct only for ldbl-128, despite being used for both types - with
diagnostic control macros as a temporary measure to disable warnings
about that constant overflowing for ldbl-128ibm - and it has a
calculation that's roughly x * log(x) - x, resulting in overflows for
arguments that are roughly at most a factor 1/log(threshold) below the
overflow threshold.
This patch fixes both issues, using an overflow threshold appropriate
for the type in question and adding another case for large arguments
that avoids the possible intermediate overflow.
Tested for x86_64, x86, mips64 and powerpc.
[BZ #16347]
[BZ #19046]
* sysdeps/ieee754/ldbl-128/e_lgammal_r.c: Do not include
<libc-internal.h>.
(MAXLGM): Do not use diagnostic control macros.
[LDBL_MANT_DIG == 106] (MAXLGM): Change value to overflow
threshold for ldbl-128ibm.
(__ieee754_lgammal_r): For large arguments, multiply by log - 1
instead of multiplying by log then subtracting.
* math/auto-libm-test-in: Add more tests of lgamma.
* math/auto-libm-test-out: Regenerated.
The ldbl-128ibm implementation of exp10l uses a version of log(10)
split into high and low parts - but the low part is negative, so
causing spurious overflows from __ieee754_expl (exp_high) in cases
close to the overflow threshold (I added relevant tests close to the
overflow threshold to the testsuite earlier today). The same issue
applies close to the underflow threshold as well (except that spurious
underflows in IBM long double arithmetic are harder to fix than the
other deficiencies, so we might end up permitting those for IBM long
double in the libm testsuite, as permitted by ISO C).
This patch fixes it to use a low part rounded downward to 48 bits
instead. (The choice of 48 instead of 53 bits is to make it more
obviously safe even when the low part of the argument is negative.)
Tested for powerpc. (Note that because of libgcc bugs with
multiplication very close to LDBL_MAX, libgcc also needs patching for
all the problem cases to be fixed, but this patch is still safe and
correct in the absence of such libgcc fixes.)
[BZ #16620]
* sysdeps/ieee754/ldbl-128ibm/e_exp10l.c (log10_high): Use value
of log (10) rounded downward to 48 bits.
(log10_low): Use corresponding low part of log (10).
For arguments with X^2 + Y^2 close to 1, clog and clog10 avoid large
errors from log(hypot) by computing X^2 + Y^2 - 1 in a way that avoids
cancellation error and then using log1p.
However, the thresholds for using that approach still result in log
being used on argument as large as sqrt(13/16) > 0.9, leading to
significant errors, in some cases above the 9ulp maximum allowed in
glibc libm. This patch arranges for the approach using log1p to be
used in any cases where |X|, |Y| < 1 and X^2 + Y^2 >= 0.5 (with the
existing allowance for cases where one of X and Y is very small),
adjusting the __x2y2m1 functions to work with the wider range of
inputs. This way, log only gets used on arguments below sqrt(1/2) (or
substantially above 1), where the error involved is much less.
Tested for x86_64, x86, mips64 and powerpc. For the ulps regeneration
I removed the existing clog and clog10 ulps before regenerating to
allow any reduced ulps to appear. Tests added include those found by
random test generation to produce large ulps either before or after
the patch, and some found by trying inputs close to the (0.75, 0.5)
threshold where the potential errors from using log are largest.
[BZ #19016]
* sysdeps/generic/math_private.h (__x2y2m1f): Update comment to
allow more cases with X^2 + Y^2 >= 0.5.
* sysdeps/ieee754/dbl-64/x2y2m1.c (__x2y2m1): Likewise. Add -1 as
normal element in sum instead of special-casing based on values of
arguments.
* sysdeps/ieee754/dbl-64/x2y2m1f.c (__x2y2m1f): Update comment.
* sysdeps/ieee754/ldbl-128/x2y2m1l.c (__x2y2m1l): Likewise. Add
-1 as normal element in sum instead of special-casing based on
values of arguments.
* sysdeps/ieee754/ldbl-128ibm/x2y2m1l.c (__x2y2m1l): Likewise.
* sysdeps/ieee754/ldbl-96/x2y2m1.c [FLT_EVAL_METHOD != 0]
(__x2y2m1): Update comment.
* sysdeps/ieee754/ldbl-96/x2y2m1l.c (__x2y2m1l): Likewise. Add -1
as normal element in sum instead of special-casing based on values
of arguments.
* math/s_clog.c (__clog): Handle more cases using log1p without
hypot.
* math/s_clog10.c (__clog10): Likewise.
* math/s_clog10f.c (__clog10f): Likewise.
* math/s_clog10l.c (__clog10l): Likewise.
* math/s_clogf.c (__clogf): Likewise.
* math/s_clogl.c (__clogl): Likewise.
* math/auto-libm-test-in: Add more tests of clog and clog10.
* math/auto-libm-test-out: Regenerated.
* sysdeps/i386/fpu/libm-test-ulps: Update.
* sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
The flt-32 version of powf can be inaccurate because of bugs in the
extra-precision calculation of (x-1)/(x+1) or (x-1.5)/(x+1.5) as part
of calculating log(x) with extra precision: a constant used (as part
of adding 1 or 1.5 through integer arithmetic) is incorrect, and then
the code fails to mask a computed high part before using it in
arithmetic that relies on s_h*t_h being exactly representable. This
patch fixes these bugs.
Tested for x86_64 and x86. x86_64 ulps for powf removed and
regenerated to reflect reduced ulps from the increased accuracy for
existing tests.
[BZ #18956]
* sysdeps/ieee754/flt-32/e_powf.c (__ieee754_powf): Add 0x00400000
not 0x0040000 for high bit of mantissa. Mask with 0xfffff000 when
extracting high part.
* math/auto-libm-test-in: Add another test of pow.
* math/auto-libm-test-out: Regenerated.
* sysdeps/x86_64/fpu/libm-test-ulps: Update.
Similar to various other bugs in this area, pow functions can fail to
raise the underflow exception when the result is tiny and inexact but
one or more low bits of the intermediate result that is scaled down
(or, in the i386 case, converted from a wider evaluation format) are
zero. This patch forces the exception in a similar way to previous
fixes, thereby concluding the fixes for known bugs with missing
underflow exceptions currently filed in Bugzilla.
Tested for x86_64, x86, mips64 and powerpc.
[BZ #18825]
* sysdeps/i386/fpu/i386-math-asm.h (FLT_NARROW_EVAL_UFLOW_NONNAN):
New macro.
(DBL_NARROW_EVAL_UFLOW_NONNAN): Likewise.
(LDBL_CHECK_FORCE_UFLOW_NONNAN): Likewise.
* sysdeps/i386/fpu/e_pow.S: Use DEFINE_DBL_MIN.
(__ieee754_pow): Use DBL_NARROW_EVAL_UFLOW_NONNAN instead of
DBL_NARROW_EVAL, reloading the PIC register as needed.
* sysdeps/i386/fpu/e_powf.S: Use DEFINE_FLT_MIN.
(__ieee754_powf): Use FLT_NARROW_EVAL_UFLOW_NONNAN instead of
FLT_NARROW_EVAL. Use separate return path for case when first
argument is NaN.
* sysdeps/i386/fpu/e_powl.S: Include <i386-math-asm.h>. Use
DEFINE_LDBL_MIN.
(__ieee754_powl): Use LDBL_CHECK_FORCE_UFLOW_NONNAN, reloading the
PIC register.
* sysdeps/ieee754/dbl-64/e_pow.c (__ieee754_pow): Use
math_check_force_underflow_nonneg.
* sysdeps/ieee754/flt-32/e_powf.c (__ieee754_powf): Force
underflow for subnormal result.
* sysdeps/ieee754/ldbl-128/e_powl.c (__ieee754_powl): Likewise.
* sysdeps/ieee754/ldbl-128ibm/e_powl.c (__ieee754_powl): Use
math_check_force_underflow_nonneg.
* sysdeps/x86/fpu/powl_helper.c (__powl_helper): Use
math_check_force_underflow.
* sysdeps/x86_64/fpu/x86_64-math-asm.h
(LDBL_CHECK_FORCE_UFLOW_NONNAN): New macro.
* sysdeps/x86_64/fpu/e_powl.S: Include <x86_64-math-asm.h>. Use
DEFINE_LDBL_MIN.
(__ieee754_powl): Use LDBL_CHECK_FORCE_UFLOW_NONNAN.
* math/auto-libm-test-in: Add more tests of pow.
* math/auto-libm-test-out: Regenerated.
Similar to various other bugs in this area, hypot functions can fail
to raise the underflow exception when the result is tiny and inexact
but one or more low bits of the intermediate result that is scaled
down (or, in the i386 case, converted from a wider evaluation format)
are zero. This patch forces the exception in a similar way to
previous fixes.
Note that this issue cannot arise for implementations of hypotf using
double (or wider) for intermediate evaluation (if hypotf should
underflow, that means the double square root is being computed of some
number of the form N*2^-298, for 0 < N < 2^46, which is exactly
represented as a double, and whatever the rounding mode such a square
root cannot have a mantissa with all zeroes after the initial 23
bits). Thus no changes are made to hypotf implementations in this
patch, only to hypot and hypotl.
Tested for x86_64, x86, mips64 and powerpc.
[BZ #18803]
* sysdeps/i386/fpu/e_hypot.S: Use DEFINE_DBL_MIN.
(MO): New macro.
(__ieee754_hypot) [PIC]: Load PIC register.
(__ieee754_hypot): Use DBL_NARROW_EVAL_UFLOW_NONNEG instead of
DBL_NARROW_EVAL.
* sysdeps/ieee754/dbl-64/e_hypot.c (__ieee754_hypot): Use
math_check_force_underflow_nonneg in case where result might be
tiny.
* sysdeps/ieee754/ldbl-128/e_hypotl.c (__ieee754_hypotl):
Likewise.
* sysdeps/ieee754/ldbl-128ibm/e_hypotl.c (__ieee754_hypotl):
Likewise.
* sysdeps/ieee754/ldbl-96/e_hypotl.c (__ieee754_hypotl): Likewise.
* sysdeps/powerpc/fpu/e_hypot.c (__ieee754_hypot): Likewise.
* math/auto-libm-test-in: Add more tests of hypot.
* math/auto-libm-test-out: Regenerated.
sysdeps/ieee754/flt-32/e_exp2f.c declares two variable as "static
const volatile float". Maybe this use of "volatile" was originally
intended to inhibit optimization of underflowing / overflowing
operations such as TWOM100 * TWOM100; in any case, it's not currently
needed, as given -frounding-math constant folding of such expressions
is properly disabled when it would be unsafe. This patch removes the
unnecessary use of "volatile".
Tested for x86_64.
* sysdeps/ieee754/flt-32/e_exp2f.c (TWOM100): Remove volatile.
(TWO127): Likewise.
Where glibc code needs to avoid excess range and precision in
floating-point arithmetic, code variously uses either asms or volatile
to force the results of that arithmetic to memory; mostly this is
conditional on FLT_EVAL_METHOD, but in the case of lrint / llrint
functions some use of volatile is unconditional (and is present
unnecessarily in versions for long double). This patch make such code
use the recently-added math_narrow_eval macro consistently, removing
the unnecessary uses of volatile in long double lrint / llrint
implementations completely.
Tested for x86_64, x86, mips64 and powerpc.
* math/s_nexttowardf.c (__nexttowardf): Use math_narrow_eval.
* stdlib/strtod_l.c: Include <math_private.h>.
(overflow_value): Use math_narrow_eval.
(underflow_value): Likewise.
* sysdeps/i386/fpu/s_nexttoward.c (__nexttoward): Likewise.
* sysdeps/i386/fpu/s_nexttowardf.c (__nexttowardf): Likewise.
* sysdeps/ieee754/dbl-64/e_gamma_r.c (gamma_positive): Likewise.
(__ieee754_gamma_r): Likewise.
* sysdeps/ieee754/dbl-64/gamma_productf.c (__gamma_productf):
Likewise.
* sysdeps/ieee754/dbl-64/k_rem_pio2.c (__kernel_rem_pio2):
Likewise.
* sysdeps/ieee754/dbl-64/lgamma_neg.c (__lgamma_neg): Likewise.
* sysdeps/ieee754/dbl-64/s_erf.c (__erfc): Likewise.
* sysdeps/ieee754/dbl-64/s_llrint.c (__llrint): Likewise.
* sysdeps/ieee754/dbl-64/s_lrint.c (__lrint): Likewise.
* sysdeps/ieee754/flt-32/e_gammaf_r.c (gammaf_positive): Likewise.
(__ieee754_gammaf_r): Likewise.
* sysdeps/ieee754/flt-32/k_rem_pio2f.c (__kernel_rem_pio2f):
Likewise.
* sysdeps/ieee754/flt-32/lgamma_negf.c (__lgamma_negf): Likewise.
* sysdeps/ieee754/flt-32/s_erff.c (__erfcf): Likewise.
* sysdeps/ieee754/flt-32/s_llrintf.c (__llrintf): Likewise.
* sysdeps/ieee754/flt-32/s_lrintf.c (__lrintf): Likewise.
* sysdeps/ieee754/ldbl-128/s_llrintl.c (__llrintl): Do not use
volatile.
* sysdeps/ieee754/ldbl-128/s_lrintl.c (__lrintl): Likewise.
* sysdeps/ieee754/ldbl-128/s_nexttoward.c (__nexttoward): Use
math_narrow_eval.
* sysdeps/ieee754/ldbl-128ibm/s_nexttoward.c (__nexttoward):
Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_nexttowardf.c (__nexttowardf):
Likewise.
* sysdeps/ieee754/ldbl-96/gamma_product.c (__gamma_product):
Likewise.
* sysdeps/ieee754/ldbl-96/s_llrintl.c (__llrintl): Do not use
volatile.
* sysdeps/ieee754/ldbl-96/s_lrintl.c (__lrintl): Likewise.
* sysdeps/ieee754/ldbl-96/s_nexttoward.c (__nexttoward): Use
math_narrow_eval.
* sysdeps/ieee754/ldbl-96/s_nexttowardf.c (__nexttowardf):
Likewise.
* sysdeps/ieee754/ldbl-opt/s_nexttowardfd.c (__nldbl_nexttowardf):
Likewise.
Various i386 libm functions return values with excess range and
precision; Wilco Dijkstra's patches to make isfinite etc. expand
inline cause this pre-existing issue to result in test failures (when
e.g. a result that overflows float but not long double gets counted as
overflowing for some purposes but not others).
This patch addresses those cases arising from functions defined in C,
adding a math_narrow_eval macro that forces values to memory to
eliminate excess precision if FLT_EVAL_METHOD indicates this is
needed, and is a no-op otherwise. I'll convert existing uses of
volatile and asm for this purpose to use the new macro later, once
i386 has clean test results again (which requires fixes for .S files
as well).
Tested for x86_64 and x86. Committed.
[BZ #18980]
* sysdeps/generic/math_private.h: Include <float.h>.
(math_narrow_eval): New macro.
[FLT_EVAL_METHOD != 0] (excess_precision): Likewise.
* sysdeps/ieee754/dbl-64/e_cosh.c (__ieee754_cosh): Use
math_narrow_eval on overflowing return value.
* sysdeps/ieee754/dbl-64/e_lgamma_r.c (__ieee754_lgamma_r):
Likewise.
* sysdeps/ieee754/dbl-64/e_sinh.c (__ieee754_sinh): Likewise.
* sysdeps/ieee754/flt-32/e_coshf.c (__ieee754_coshf): Likewise.
* sysdeps/ieee754/flt-32/e_lgammaf_r.c (__ieee754_lgammaf_r):
Likewise.
* sysdeps/ieee754/flt-32/e_sinhf.c (__ieee754_sinhf): Likewise.
Bug 15384 notes that in __finite, two different constants are used
that could be the same constant (the result only depends on the
exponent of the floating-point representation), and that using the
same constant is better for architectures where constants need loading
from a constant pool. This patch implements that change.
Tested for x86_64, mips64 and powerpc.
[BZ #15384]
* sysdeps/ieee754/dbl-64/s_finite.c (FINITE): Use same constant as
bit-mask as in subtraction.
* sysdeps/ieee754/dbl-64/wordsize-64/s_finite.c (__finite):
Likewise.
* sysdeps/ieee754/flt-32/s_finitef.c (FINITEF): Likewise.
* sysdeps/ieee754/ldbl-128/s_finitel.c (__finitel): Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_finitel.c (__finitel): Likewise.
Similar to various other bugs in this area, tgamma functions can fail
to raise the underflow exception when the result is tiny and inexact
but one or more low bits of the intermediate result that is scaled
down are zero. This patch forces the exception in a similar way to
previous fixes.
Tested for x86_64, x86, mips64 and powerpc.
[BZ #18951]
* sysdeps/ieee754/dbl-64/e_gamma_r.c (__ieee754_gamma_r): Force
underflow exception for small results.
* sysdeps/ieee754/flt-32/e_gammaf_r.c (__ieee754_gammaf_r):
Likewise.
* sysdeps/ieee754/ldbl-128/e_gammal_r.c (__ieee754_gammal_r):
Likewise.
* sysdeps/ieee754/ldbl-128ibm/e_gammal_r.c (__ieee754_gammal_r):
Likewise.
* sysdeps/ieee754/ldbl-96/e_gammal_r.c (__ieee754_gammal_r):
Likewise.
* math/auto-libm-test-in: Add more tests of tgamma.
* math/auto-libm-test-out: Regenerated.
As noted in bug 6803, scalbn fails to set errno on overflow and
underflow. This patch fixes this by making scalbn an alias of ldexp,
which has exactly the same semantics (for floating-point types with
radix 2) and already has wrappers that deal with setting errno,
instead of an alias of the internal __scalbn (which ldexp calls).
Notes:
* Where compat symbols were defined for scalbn functions, I didn't
change what they point to (to keep the patch minimal), so such
compat symbols continue to go directly to the non-errno-setting
functions.
* Mike, I didn't do anything with the IA64 versions of these
functions, where I think both the ldexp and scalbn functions already
deal with setting errno. As a cleanup (not needed to fix this bug)
however you might want to make those functions into aliases for
IA64; there is no need for them to be separate function
implementations at all.
* This concludes the fix for bug 6803 since the scalb and scalbln
cases of that bug were fixed some time ago.
Tested for x86_64, x86, mips64 and powerpc.
[BZ #6803]
* math/s_ldexp.c (scalbn): Define as weak alias of __ldexp.
[NO_LONG_DOUBLE] (scalbnl): Define as weak alias of __ldexp.
* math/s_ldexpf.c (scalbnf): Define as weak alias of __ldexpf.
* math/s_ldexpl.c (scalbnl): Define as weak alias of __ldexpl.
* sysdeps/i386/fpu/s_scalbn.S (scalbn): Remove alias.
* sysdeps/i386/fpu/s_scalbnf.S (scalbnf): Likewise.
* sysdeps/i386/fpu/s_scalbnl.S (scalbnl): Likewise.
* sysdeps/ieee754/dbl-64/s_scalbn.c (scalbn): Likewise.
[NO_LONG_DOUBLE] (scalbnl): Likewise.
* sysdeps/ieee754/dbl-64/wordsize-64/s_scalbn.c (scalbn):
Likewise.
[NO_LONG_DOUBLE] (scalbnl): Likewise.
* sysdeps/ieee754/flt-32/s_scalbnf.c (scalbnf): Likewise.
* sysdeps/ieee754/ldbl-128/s_scalbnl.c (scalbnl): Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_scalbnl.c (scalbnl): Remove
long_double_symbol calls.
* sysdeps/ieee754/ldbl-64-128/s_scalbnl.c (scalbnl): Likewise.
* sysdeps/ieee754/ldbl-opt/s_ldexpl.c (__ldexpl_2): Define as
strong alias of __ldexpl.
(scalbnl): Define using long_double_symbol.
* sysdeps/m68k/m680x0/fpu/s_scalbn.c (__CONCATX(scalbn,suffix)):
Remove alias.
* sysdeps/sparc/sparc64/soft-fp/s_scalbnl.c (scalbnl): Likewise.
* sysdeps/x86_64/fpu/s_scalbnl.S (scalbnl): Likewise.
* math/libm-test.inc (scalbn_test_data): Add errno expectations.
(scalbln_test_data): Add more errno expectations.
The ldbl-128 and ldbl-128ibm expm1l implementations have code to
handle +Inf and finite arguments above an overflow threshold. Since
they now use __expl for large positive arguments to fix other
problems, this code is unreachable; this patch removes it.
Tested for mips64 and powerpc.
[BZ #16415]
* sysdeps/ieee754/ldbl-128/s_expm1l.c (maxlog): Remove variable.
(__expm1l): Remove code to handle positive infinity and overflow.
* sysdeps/ieee754/ldbl-128ibm/s_expm1l.c (maxlog): Remove
variable.
(__expm1l): Remove code to handle positive infinity and overflow.
The ldbl-128ibm implementation of nearbyintl wrongly uses signaling
comparisons such as "if (fabs (u.d[0].d) < TWO52)" on arguments that
might be NaNs, when "invalid" exceptions should not be raised. (For
hard float, this issue may be hidden by
<https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58684>, powerpc GCC
wrongly only using unordered comparison instructions.) This patch
fixes this by just returning the argument if it is not finite (because
of the arbitrary value of the low part of a NaN in IBM long double,
there are quite a lot of comparisons that could end up involving a NaN
when the argument to nearbyintl is a NaN, so excluding NaN arguments
at the start is the simplest and safest fix).
Tested for powerpc-nofpu, where it removes failures for spurious
"invalid" exceptions from nearbyintl.
[BZ #18857]
* sysdeps/ieee754/ldbl-128ibm/s_nearbyintl.c (__nearbyintl): Just
return non-finite argument without doing ordered comparisons on
it.
Bug 15918 points out that the handling of infinities in hypotf can be
simplified: it's enough to return the absolute value of the infinite
argument without first comparing it to the other argument and possibly
returning that other argument's absolute value. This patch makes that
cleanup (which should not change how hypotf behaves on any input).
Tested for x86_64.
[BZ #15918]
* sysdeps/ieee754/flt-32/e_hypotf.c (__ieee754_hypotf): Simplify
handling of cases where one argument is an infinity.
Various exp2 implementations in glibc can miss underflow exceptions
when the scaling down part of the calculation is exact (or, in the x86
case, when the conversion from extended precision to the target
precision is exact). This patch forces the exception in a similar way
to previous fixes.
The x86 exp2f changes may in fact not be needed for this purpose -
it's likely to be the case that no argument of type float has an exp2
result so close to an exact subnormal float value that it equals that
value when rounded to 64 bits (even taking account of variation
between different x86 implementations). However, they are included
for consistency with the changes to exp2 and so as to fix the exp2f
part of bug 18875 by ensuring that excess range and precision is
removed from underflowing return values.
Tested for x86_64, x86 and mips64.
[BZ #16521]
[BZ #18875]
* math/e_exp2l.c (__ieee754_exp2l): Force underflow exception for
small results.
* sysdeps/i386/fpu/e_exp2.S (dbl_min): New object.
(MO): New macro.
(__ieee754_exp2): For small results, force underflow exception and
remove excess range and precision from return value.
* sysdeps/i386/fpu/e_exp2f.S (flt_min): New object.
(MO): New macro.
(__ieee754_exp2f): For small results, force underflow exception
and remove excess range and precision from return value.
* sysdeps/i386/fpu/e_exp2l.S (ldbl_min): New object.
(MO): New macro.
(__ieee754_exp2l): Force underflow exception for small results.
* sysdeps/ieee754/dbl-64/e_exp2.c (__ieee754_exp2): Likewise.
* sysdeps/ieee754/flt-32/e_exp2f.c (__ieee754_exp2f): Likewise.
* sysdeps/x86_64/fpu/e_exp2l.S (ldbl_min): New object.
(MO): New macro.
(__ieee754_exp2l): Force underflow exception for small results.
* math/auto-libm-test-in: Add more tests or exp2.
* math/auto-libm-test-out: Regenerated.
The ldbl-128 / ldbl-128ibm implementation of lgammal converts (the
floor of minus) non-integer negative arguments to int to determine the
value of signgam. When those values are outside the range of int,
this produces spurious "invalid" exceptions and incorrect values of
signgam. This patch fixes this by instead determining signgam through
comparing half the integer in question to floor of half the integer.
Tested for mips64, x86_64 and x86.
[BZ #18952]
* sysdeps/ieee754/ldbl-128/e_lgammal_r.c (__ieee754_lgammal_r): Do
not convert non-integer negative arguments to int to determine the
value of signgam.
* math/auto-libm-test-in: Add more tests of lgamma.
* math/auto-libm-test-out: Regenerated.
The existing implementations of lgamma functions (except for the ia64
versions) use the reflection formula for negative arguments. This
suffers large inaccuracy from cancellation near zeros of lgamma (near
where the gamma function is +/- 1).
This patch fixes this inaccuracy. For arguments above -2, there are
no zeros and no large cancellation, while for sufficiently large
negative arguments the zeros are so close to integers that even for
integers +/- 1ulp the log(gamma(1-x)) term dominates and cancellation
is not significant. Thus, it is only necessary to take special care
about cancellation for arguments around a limited number of zeros.
Accordingly, this patch uses precomputed tables of relevant zeros,
expressed as the sum of two floating-point values. The log of the
ratio of two sines can be computed accurately using log1p in cases
where log would lose accuracy. The log of the ratio of two gamma(1-x)
values can be computed using Stirling's approximation (the difference
between two values of that approximation to lgamma being computable
without computing the two values and then subtracting), with
appropriate adjustments (which don't reduce accuracy too much) in
cases where 1-x is too small to use Stirling's approximation directly.
In the interval from -3 to -2, using the ratios of sines and of
gamma(1-x) can still produce too much cancellation between those two
parts of the computation (and that interval is also the worst interval
for computing the ratio between gamma(1-x) values, which computation
becomes more accurate, while being less critical for the final result,
for larger 1-x). Because this can result in errors slightly above
those accepted in glibc, this interval is instead dealt with by
polynomial approximations. Separate polynomial approximations to
(|gamma(x)|-1)(x-n)/(x-x0) are used for each interval of length 1/8
from -3 to -2, where n (-3 or -2) is the nearest integer to the
1/8-interval and x0 is the zero of lgamma in the relevant half-integer
interval (-3 to -2.5 or -2.5 to -2).
Together, the two approaches are intended to give sufficient accuracy
for all negative arguments in the problem range. Outside that range,
the previous implementation continues to be used.
Tested for x86_64, x86, mips64 and powerpc. The mips64 and powerpc
testing shows up pre-existing problems for ldbl-128 and ldbl-128ibm
with large negative arguments giving spurious "invalid" exceptions
(exposed by newly added tests for cases this patch doesn't affect the
logic for); I'll address those problems separately.
[BZ #2542]
[BZ #2543]
[BZ #2558]
* sysdeps/ieee754/dbl-64/e_lgamma_r.c (__ieee754_lgamma_r): Call
__lgamma_neg for arguments from -28.0 to -2.0.
* sysdeps/ieee754/flt-32/e_lgammaf_r.c (__ieee754_lgammaf_r): Call
__lgamma_negf for arguments from -15.0 to -2.0.
* sysdeps/ieee754/ldbl-128/e_lgammal_r.c (__ieee754_lgammal_r):
Call __lgamma_negl for arguments from -48.0 or -50.0 to -2.0.
* sysdeps/ieee754/ldbl-96/e_lgammal_r.c (__ieee754_lgammal_r):
Call __lgamma_negl for arguments from -33.0 to -2.0.
* sysdeps/ieee754/dbl-64/lgamma_neg.c: New file.
* sysdeps/ieee754/dbl-64/lgamma_product.c: Likewise.
* sysdeps/ieee754/flt-32/lgamma_negf.c: Likewise.
* sysdeps/ieee754/flt-32/lgamma_productf.c: Likewise.
* sysdeps/ieee754/ldbl-128/lgamma_negl.c: Likewise.
* sysdeps/ieee754/ldbl-128/lgamma_productl.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/lgamma_negl.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/lgamma_productl.c: Likewise.
* sysdeps/ieee754/ldbl-96/lgamma_negl.c: Likewise.
* sysdeps/ieee754/ldbl-96/lgamma_product.c: Likewise.
* sysdeps/ieee754/ldbl-96/lgamma_productl.c: Likewise.
* sysdeps/generic/math_private.h (__lgamma_negf): New prototype.
(__lgamma_neg): Likewise.
(__lgamma_negl): Likewise.
(__lgamma_product): Likewise.
(__lgamma_productl): Likewise.
* math/Makefile (libm-calls): Add lgamma_neg and lgamma_product.
* math/auto-libm-test-in: Add more tests of lgamma.
* math/auto-libm-test-out: Regenerated.
* sysdeps/i386/fpu/libm-test-ulps: Update.
* sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
As with other spots in the code, GCC 4.8 unnecessarily complains about
an uninitialized variable in tanl calcs, so this patch disables. With
it, the library and sees the usual set of test passes.
* sysdeps/ieee754/ldbl-96/k_tanl.c: Include <libc-internal.h>.
(__kernel_tanl): Ignore uninitialized warnings around use of SIGN.
Removing the use of -Wno-uninitialized for math/ shows errors for
ldbl-128ibm:
../sysdeps/ieee754/ldbl-128ibm/s_nearbyintl.c: In function '__nearbyintl':
../sysdeps/ieee754/ldbl-128ibm/s_nearbyintl.c:119:34: error: 'low' may be used uninitialized in this function [-Werror=maybe-uninitialized]
u.d[1].d = high - u.d[0].d + low;
^
../sysdeps/ieee754/ldbl-128ibm/s_nearbyintl.c:119:23: error: 'high' may be used uninitialized in this function [-Werror=maybe-uninitialized]
u.d[1].d = high - u.d[0].d + low;
^
These errors are correct: if the high part of the argument is a NaN,
and the low part is nonzero but has absolute value less than 2^52,
those variables can be used uninitialized. This patch rearranges the
code so that the variables are always initialized with the natural
values, and then possibly modified later, to avoid this uninitialized
use. (Note that there are still other issues with this code and NaNs
that are not fixed by this patch.) No bug filed in Bugzilla or
testcase added for the uninitialized use since it wasn't user-visible
with the compiler I tried (that is, I still got a NaN result).
Tested for powerpc.
* sysdeps/ieee754/ldbl-128ibm/s_nearbyintl.c: Always initialize
variables for high and low parts before possibly modifying them.
Various fma implementations have logic that, when computing fma (x, y,
z) where z is large (so care needs taking to avoid internal overflow)
but x * y is small, scale x * y up instead of down to avoid internal
underflows resulting from scaling down. (In these cases, x * y is
small enough that only its sign actually matters rather than the exact
value.)
The threshold for scaling up instead of down was correct for "if the
unscaled values were multiplied, the low part of the multiplication
could underflow", and the scaling was sufficient to ensure that the
low part of the multiplication did not underflow (given that cases of
very small x * y - less than half the least subnormal - were
previously dealt with). However, the choice in the functions wasn't
between scaling up or no scaling, but between scaling up and scaling
down (scaling down actually being needed when x * y isn't so small
compared to z and so the exact value does matter). Thus a larger
threshold is needed to ensure that scaling down doesn't produce values
the multiplication of whose low parts underflows. This patch
increases the thresholds accordingly.
Tested for x86_64, x86 and mips64 (with the MIPS version of s_fmal.c
removed so that the ldbl-128 version gets tested instead of the
soft-fp one).
[BZ #18824]
* sysdeps/ieee754/dbl-64/s_fma.c (__fma): Increase threshold for
scaling x * y up instead of down.
* sysdeps/ieee754/ldbl-128/s_fmal.c (__fmal): Likewise.
* sysdeps/ieee754/ldbl-96/s_fmal.c (__fmal): Likewise.
* math/auto-libm-test-in: Add more tests of fma.
* math/auto-libm-test-out: Regenerated.
Similar to various other bugs in this area, some tanh implementations
do not raise the underflow exception for subnormal arguments, when the
result is tiny and inexact. This patch forces the exception in a
similar way to previous fixes.
Tested for x86_64, x86, mips64 and powerpc.
[BZ #16520]
* sysdeps/ieee754/dbl-64/s_tanh.c: Include <float.h>.
(__tanh): Force underflow exception for arguments with small
absolute value.
* sysdeps/ieee754/flt-32/s_tanhf.c: Include <float.h>.
(__tanhf): Force underflow exception for arguments with small
absolute value.
* sysdeps/ieee754/ldbl-128/s_tanhl.c: Include <float.h>.
(__tanhl): Force underflow exception for arguments with small
absolute value.
* sysdeps/ieee754/ldbl-128ibm/s_tanhl.c: Include <float.h>.
(__tanhl): Force underflow exception for arguments with small
absolute value.
* sysdeps/ieee754/ldbl-96/s_tanhl.c: Include <float.h>.
(__tanhl): Force underflow exception for arguments with small
absolute value.
* math/auto-libm-test-in: Add more tests of tanh.
* math/auto-libm-test-out: Regenerated.
* sysdeps/i386/fpu/libm-test-ulps: Update.
ldbl-128ibm tanhl uses a too-small threshold to decide when to return
+/-1, resulting in large errors. This patch changes it to a more
appropriate threshold (the requirement is for 2*exp(-2|x|) to be small
in terms of ulps of 1).
Tested for x86_64, x86 and powerpc.
[BZ #18790]
* sysdeps/ieee754/ldbl-128ibm/s_tanhl.c (__tanhl): Increase
threshold for returning +/- 1.
* math/auto-libm-test-in: Add more tests of tanh.
* math/auto-libm-test-out: Regenerated.
* sysdeps/i386/fpu/libm-test-ulps: Update.
ldbl-128ibm sinhl uses a too-big threshold to decide when to return
the argument, resulting in large errors. This patch fixes it to use a
more appropriate threshold.
Tested for x86_64, x86 and powerpc.
[BZ #18789]
* sysdeps/ieee754/ldbl-128ibm/e_sinhl.c (__ieee754_sinhl): Use
smaller threshold for returning the argument.
* math/auto-libm-test-in: Add more tests of sinh.
* math/auto-libm-test-out: Regenerated.
* sysdeps/i386/fpu/libm-test-ulps: Update.
Similar to various other bugs in this area, some tan implementations
do not raise the underflow exception for subnormal arguments, when the
result is tiny and inexact. This patch forces the exception in a
similar way to previous fixes.
Tested for x86_64, x86, mips64 and powerpc.
[BZ #16517]
* sysdeps/ieee754/dbl-64/s_tan.c: Include <float.h>.
(tan): Force underflow exception for arguments with small absolute
value.
* sysdeps/ieee754/flt-32/k_tanf.c: Include <float.h>.
(__kernel_tanf): Force underflow exception for arguments with
small absolute value.
* sysdeps/ieee754/ldbl-128/k_tanl.c: Include <float.h>.
(__kernel_tanl): Force underflow exception for arguments with
small absolute value.
* sysdeps/ieee754/ldbl-128ibm/k_tanl.c: Include <float.h>.
(__kernel_tanl): Force underflow exception for arguments with
small absolute value.
* sysdeps/ieee754/ldbl-96/k_tanl.c: Include <float.h>.
(__kernel_tanl): Force underflow exception for arguments with
small absolute value.
* math/auto-libm-test-in: Add more tests of tan.
* math/auto-libm-test-out: Regenerated.
Similar to various other bugs in this area, some sinh implementations
do not raise the underflow exception for subnormal arguments, when the
result is tiny and inexact. This patch forces the exception in a
similar way to previous fixes.
Tested for x86_64, x86, mips64 and powerpc.
[BZ #16519]
* sysdeps/ieee754/dbl-64/e_sinh.c: Include <float.h>.
(__ieee754_sinh): Force underflow exception for arguments with
small absolute value.
* sysdeps/ieee754/flt-32/e_sinhf.c: Include <float.h>.
(__ieee754_sinhf): Force underflow exception for arguments with
small absolute value.
* sysdeps/ieee754/ldbl-128/e_sinhl.c: Include <float.h>.
(__ieee754_sinhl): Force underflow exception for arguments with
small absolute value.
* sysdeps/ieee754/ldbl-128ibm/e_sinhl.c: Include <float.h>.
(__ieee754_sinhl): Force underflow exception for arguments with
small absolute value.
* sysdeps/ieee754/ldbl-96/e_sinhl.c: Include <float.h>.
(__ieee754_sinhl): Force underflow exception for arguments with
small absolute value.
* math/auto-libm-test-in: Add more tests of sinh.
* math/auto-libm-test-out: Regenerated.
* sysdeps/i386/fpu/libm-test-ulps: Update.
The flt-32 implementation of powf wrongly uses x-1 instead of |x|-1
when computing log (x) for the case where |x| is close to 1 and y is
large. This patch fixes the logic accordingly. Relevant tests
existed for x close to 1, and corresponding tests are added for x
close to -1, as well as for some new variant cases.
Tested for x86_64 and x86.
[BZ #18647]
* sysdeps/ieee754/flt-32/e_powf.c (__ieee754_powf): For large y
and |x| close to 1, use absolute value of x when computing log.
* math/auto-libm-test-in: Add more tests of pow.
* math/auto-libm-test-out: Regenerated.
In the ldbl-128 implementation of expm1l, when expm1l's result should
underflow to 0 (argument minus the least subnormal, in some rounding
modes), it can be a zero of the wrong sign. This patch fixes this in
the same way previously used for the x86 / x86_64 versions.
Tested for mips64.
[BZ #18619]
* sysdeps/ieee754/ldbl-128/s_expm1l.c (__expm1l): Force underflow
and return argument in case of subnormal argument.
In non-default rounding modes, tgamma can be slightly less accurate
than permitted by glibc's accuracy goals.
Part of the problem is error accumulation, addressed in this patch by
setting round-to-nearest for internal computations. However, there
was also a bug in the code dealing with computing pow (x + n, x + n)
where x + n is not exactly representable, providing another source of
error even in round-to-nearest mode; it was necessary to address both
bugs to get errors for all testcases within glibc's accuracy goals.
Given this second fix, accuracy in round-to-nearest mode is also
improved (hence regeneration of ulps for tgamma should be from scratch
- truncate libm-test-ulps or at least remove existing tgamma entries -
so that the expected ulps can be reduced).
Some additional complications also arose. Certain tgamma tests should
strictly, according to IEEE semantics, overflow or not depending on
the rounding mode; this is beyond the scope of glibc's accuracy goals
for any function without exactly-determined results, but
gen-auto-libm-tests doesn't handle being lax there as it does for
underflow. (libm-test.inc also doesn't handle being lax about whether
the result in cases very close to the overflow threshold is infinity
or a finite value close to overflow, but that doesn't cause problems
in this case though I've seen it cause problems with random test
generation for some functions.) Thus, spurious-overflow markings,
with a comment, are added to auto-libm-test-in (no bug in Bugzilla
because the issue is with the testsuite, not a user-visible bug in
glibc). And on x86, after the patch I saw ERANGE issues as previously
reported by Carlos (see my commentary in
<https://sourceware.org/ml/libc-alpha/2015-01/msg00485.html>), which
needed addressing by ensuring excess range and precision were
eliminated at various points if FLT_EVAL_METHOD != 0.
I also noticed and fixed a cosmetic issue where 1.0f was used in long
double functions and should have been 1.0L.
This completes the move of all functions to testing in all rounding
modes with ALL_RM_TEST, so gen-libm-have-vector-test.sh is updated to
remove the workaround for some functions not using ALL_RM_TEST.
Tested for x86_64, x86, mips64 and powerpc.
[BZ #18613]
* sysdeps/ieee754/dbl-64/e_gamma_r.c (gamma_positive): Take log of
X_ADJ not X when adjusting exponent.
(__ieee754_gamma_r): Do intermediate computations in
round-to-nearest then adjust overflowing and underflowing results
as needed.
* sysdeps/ieee754/flt-32/e_gammaf_r.c (gammaf_positive): Take log
of X_ADJ not X when adjusting exponent.
(__ieee754_gammaf_r): Do intermediate computations in
round-to-nearest then adjust overflowing and underflowing results
as needed.
* sysdeps/ieee754/ldbl-128/e_gammal_r.c (gammal_positive): Take
log of X_ADJ not X when adjusting exponent.
(__ieee754_gammal_r): Do intermediate computations in
round-to-nearest then adjust overflowing and underflowing results
as needed. Use 1.0L not 1.0f as numerator of division.
* sysdeps/ieee754/ldbl-128ibm/e_gammal_r.c (gammal_positive): Take
log of X_ADJ not X when adjusting exponent.
(__ieee754_gammal_r): Do intermediate computations in
round-to-nearest then adjust overflowing and underflowing results
as needed. Use 1.0L not 1.0f as numerator of division.
* sysdeps/ieee754/ldbl-96/e_gammal_r.c (gammal_positive): Take log
of X_ADJ not X when adjusting exponent.
(__ieee754_gammal_r): Do intermediate computations in
round-to-nearest then adjust overflowing and underflowing results
as needed. Use 1.0L not 1.0f as numerator of division.
* math/libm-test.inc (tgamma_test_data): Remove one test. Moved
to auto-libm-test-in.
(tgamma_test): Use ALL_RM_TEST.
* math/auto-libm-test-in: Add one test of tgamma. Mark some other
tests of tgamma with spurious-overflow.
* math/auto-libm-test-out: Regenerated.
* math/gen-libm-have-vector-test.sh: Do not check for START.
* sysdeps/i386/fpu/libm-test-ulps: Update.
* sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
The ldbl-128 implementation of j1l produces spurious underflow
exceptions for some small arguments, as a result of squaring the
argument. This patch fixes it just to use a linear approximation for
sufficiently small arguments, and then to force an underflow exception
only in the cases where it is required.
Tested for mips64.
[BZ #18612]
* sysdeps/ieee754/ldbl-128/e_j1l.c (__ieee754_j1l): For small
arguments, just return 0.5 times the argument, with underflow
forced as needed.
* math/auto-libm-test-in: Add more tests of j1.
* math/auto-libm-test-out: Regenerated.
Similar to various other bugs in this area, j1 and jn implementations
can fail to raise the underflow exception when the internal
computation is exact although the actual function is inexact. This
patch forces the exception in a similar way to other such fixes. (The
ldbl-128 / ldbl-128ibm j1l implementation is different and doesn't
need a change for this until spurious underflows in it are fixed.)
Tested for x86_64, x86, mips64 and powerpc.
[BZ #16559]
* sysdeps/ieee754/dbl-64/e_j1.c: Include <float.h>.
(__ieee754_j1): Force underflow exception for small results.
* sysdeps/ieee754/dbl-64/e_jn.c (__ieee754_jn): Likewise.
* sysdeps/ieee754/flt-32/e_j1f.c: Include <float.h>.
(__ieee754_j1f): Force underflow exception for small results.
* sysdeps/ieee754/flt-32/e_jnf.c (__ieee754_jnf): Likewise.
* sysdeps/ieee754/ldbl-128/e_jnl.c (__ieee754_jnl): Likewise.
* sysdeps/ieee754/ldbl-128ibm/e_jnl.c (__ieee754_jnl): Likewise.
* sysdeps/ieee754/ldbl-96/e_j1l.c: Include <float.h>.
(__ieee754_j1l): Force underflow exception for small results.
* sysdeps/ieee754/ldbl-96/e_jnl.c (__ieee754_jnl): Likewise.
* math/auto-libm-test-in: Add more tests of j1 and jn.
* math/auto-libm-test-out: Regenerated.
Some existing jn tests, if run in non-default rounding modes, produce
errors above those accepted in glibc, which causes problems for moving
tests of jn to use ALL_RM_TEST. This patch makes jn set rounding
to-nearest internally, as was done for yn some time ago, then computes
the appropriate underflowing value for results that underflowed to
zero in to-nearest, and moves the tests to ALL_RM_TEST. It does
nothing about the general inaccuracy of Bessel function
implementations in glibc, though it should make jn more accurate on
average in non-default rounding modes through reduced error
accumulation. The recomputation of results that underflowed to zero
should as a side-effect fix some cases of bug 16559, where jn just
used an exact zero, but that is *not* the goal of this patch and other
cases of that bug remain unfixed.
(Most of the changes in the patch are reindentation to add new scopes
for SET_RESTORE_ROUND*.)
Tested for x86_64, x86, powerpc and mips64.
[BZ #16559]
[BZ #18602]
* sysdeps/ieee754/dbl-64/e_jn.c (__ieee754_jn): Set
round-to-nearest internally then recompute results that
underflowed to zero in the original rounding mode.
* sysdeps/ieee754/flt-32/e_jnf.c (__ieee754_jnf): Likewise.
* sysdeps/ieee754/ldbl-128/e_jnl.c (__ieee754_jnl): Likewise.
* sysdeps/ieee754/ldbl-128ibm/e_jnl.c (__ieee754_jnl): Likewise.
* sysdeps/ieee754/ldbl-96/e_jnl.c (__ieee754_jnl): Likewise
* math/libm-test.inc (jn_test): Use ALL_RM_TEST.
* sysdeps/i386/fpu/libm-test-ulps: Update.
* sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
Similar to various other bugs in this area, the ldbl-128 expl
implementation does not raise the underflow exception for all
subnormal results, if the scaling down is exact although the actual
result is inexact. This patch fixes this by forcing the exception in
this case (the tests that failed before and pass after the test are
already in the testsuite).
Tested for mips64.
[BZ #18586]
* sysdeps/ieee754/ldbl-128/e_expl.c (__ieee754_expl): Force
underflow exception for small results.
Similar to various other bugs in this area, some sin and sincos
implementations do not raise the underflow exception for subnormal
arguments, when the result is tiny and inexact. This patch forces the
exception in a similar way to previous fixes.
Tested for x86_64, x86, mips64 and powerpc.
[BZ #16526]
[BZ #16538]
* sysdeps/ieee754/dbl-64/s_sin.c: Include <float.h>.
(__sin): Force underflow exception for arguments with small
absolute value.
* sysdeps/ieee754/flt-32/k_sinf.c: Include <float.h>.
(__kernel_sinf): Force underflow exception for arguments with
small absolute value.
* sysdeps/ieee754/ldbl-128/k_sincosl.c: Include <float.h>.
(__kernel_sincosl): Force underflow exception for arguments with
small absolute value.
* sysdeps/ieee754/ldbl-128/k_sinl.c: Include <float.h>.
(__kernel_sinl): Force underflow exception for arguments with
small absolute value.
* sysdeps/ieee754/ldbl-128ibm/k_sincosl.c: Include <float.h>.
(__kernel_sincosl): Force underflow exception for arguments with
small absolute value.
* sysdeps/ieee754/ldbl-128ibm/k_sinl.c: Include <float.h>.
(__kernel_sinl): Force underflow exception for arguments with
small absolute value.
* sysdeps/ieee754/ldbl-96/k_sinl.c: Include <float.h>.
(__kernel_sinl): Force underflow exception for arguments with
small absolute value.
* sysdeps/powerpc/fpu/k_sinf.c: Include <float.h>.
(__kernel_sinf): Force underflow exception for arguments with
small absolute value.
* math/auto-libm-test-in: Add more tests of sin and sincos.
* math/auto-libm-test-out: Regenerated.
__kernel_standard_l converts long double arguments to double for use
in SVID "struct exception". This has special-case handling for when
that conversion would overflow or underflow but the original long
double function wouldn't. However, it turns out that "inexact"
exceptions can be spurious here as well, when the function is exactly
determined and __kernel_standard_l is being called for a domain error.
This patch fixes this by using feholdexcept / fesetenv to avoid
exceptions from the conversion, replacing the previous special-case
logic for overflow and underflow (this covers all functions using
__kernel_standard_l, not just those that actually need a change, since
there doesn't seem to be much point in restricting things just to the
functions that mustn't get "inexact" here).
Tested for x86_64 and x86.
[BZ #18245]
[BZ #18583]
* sysdeps/ieee754/k_standardl.c: Include <fenv.h>.
(__kernel_standard_l): Use feholdexcept and fesetenv around
conversion to double instead of special-casing overflow and
underflow.
* math/libm-test.inc (fmod_test_data): Add more tests.
(remainder_test_data): Likewise.
(sqrt_test_data): Likewise.
The dbl-64 and flt-32 implementations of exp2 functions produce
spurious underflow exceptions. The underlying reason is the same in
both cases: the computation works as (2^a - 1)*2^b + 2^b for suitably
chosen a and b, where a has small magnitude so 2^a - 1 can be computed
with a low-degree polynomial approximation, and (2^a - 1)*2^b can
underflow even when the final result does not. This patch fixes this
by adjusting the threshold for when scaling is used to avoid
intermediate underflow so it works for any possible value of a where
the final result would not underflow.
Tested for x86_64 and x86.
[BZ #18219]
* sysdeps/ieee754/dbl-64/e_exp2.c (__ieee754_exp2): Reduce
threshold on absolute value of exponent for which scaling is used.
* sysdeps/ieee754/flt-32/e_exp2f.c (__ieee754_exp2f): Likewise.
* math/auto-libm-test-in: Add more tests of exp2.
* math/auto-libm-test-out: Regenerated.
Similar to various other bugs in this area, some expm1 implementations
do not raise the underflow exception for subnormal arguments, when the
result is tiny and inexact. This patch forces the exception in a
similar way to previous fixes.
(The issue does not apply to the ldbl-* implementations or to those
for x86 / x86_64 long double. The change to
sysdeps/ieee754/dbl-64/wordsize-64/e_cosh.c is one I missed when
previously fixing bug 16354; the bug in that implementation was
previously latent, but the expm1 fixes stopped it being latent and so
required it to be fixed to avoid spurious underflows from cosh.)
Tested for x86_64 and x86.
[BZ #16353]
* sysdeps/i386/fpu/s_expm1.S (dbl_min): New object.
(__expm1): Force underflow exception for arguments with small
absolute value.
* sysdeps/i386/fpu/s_expm1f.S (flt_min): New object.
(__expm1f): Force underflow exception for arguments with small
absolute value.
* sysdeps/ieee754/dbl-64/s_expm1.c: Include <float.h>.
(__expm1): Force underflow exception for arguments with small
absolute value.
* sysdeps/ieee754/flt-32/s_expm1f.c: Include <float.h>.
(__expm1f): Force underflow exception for arguments with small
absolute value.
* sysdeps/ieee754/dbl-64/wordsize-64/e_cosh.c (__ieee754_cosh):
Check for small arguments before calling __expm1.
* math/auto-libm-test-in: Do not mark underflow exceptions as
possibly missing for bug 16353.
* math/auto-libm-test-out: Regenerated.
Similar to various other bugs in this area, some asinh implementations
do not raise the underflow exception for subnormal arguments, when the
result is tiny and inexact. This patch forces the exception in a
similar way to previous fixes.
Tested for x86_64, x86 and mips64.
[BZ #16350]
* sysdeps/i386/fpu/s_asinh.S (__asinh): Force underflow exception
for arguments with small absolute value.
* sysdeps/i386/fpu/s_asinhf.S (__asinhf): Likewise.
* sysdeps/i386/fpu/s_asinhl.S (__asinhl): Likewise.
* sysdeps/ieee754/dbl-64/s_asinh.c: Include <float.h>.
(__asinh): Force underflow exception for arguments with small
absolute value.
* sysdeps/ieee754/flt-32/s_asinhf.c: Include <float.h>.
(__asinhf): Force underflow exception for arguments with small
absolute value.
* sysdeps/ieee754/ldbl-128/s_asinhl.c: Include <float.h>.
(__asinhl): Force underflow exception for arguments with small
absolute value.
* sysdeps/ieee754/ldbl-128ibm/s_asinhl.c: Include <float.h>.
(__asinhl): Force underflow exception for arguments with small
absolute value.
* sysdeps/ieee754/ldbl-96/s_asinhl.c: Include <float.h>.
(__asinhl): Force underflow exception for arguments with small
absolute value.
* math/auto-libm-test-in: Do not mark underflow exceptions as
possibly missing for bug 16350.
* math/auto-libm-test-out: Regenerated.
sysdeps/ieee754/ldbl-128ibm has its own versions of cprojl, ctanhl and
ctanl.
Having its own versions, where otherwise the math/ copies are
generally used for all floating-point formats, means they are liable
to get out of sync and not benefit from bug fixes to the generic
versions. The substantive differences (not arising from getting out
of sync and slightly different fixes for the same issues) are: long
double compat handling (also done in the ldbl-opt versions, so doesn't
require special versions for ldbl-128ibm); handling of LDBL_EPSILON
(conditionally undefined and redefined in other math/ implementations,
so doesn't justify a special version), and:
/* __gcc_qmul does not respect -0.0 so we need the following fixup. */
if ((__real__ res == 0.0L) && (__real__ x == 0.0L))
__real__ res = __real__ x;
if ((__real__ res == 0.0L) && (__imag__ x == 0.0L))
__imag__ res = __imag__ x;
But if that statement about __gcc_qmul was ever true for an old
version of that libgcc function, it's not the case for any GCC version
now supported to build glibc; there's explicit logic early in that
function (and similarly in __gcc_qdiv) to return an appropriately
signed zero if the product of the high parts is zero. So this patch
adds the special LDBL_EPSILON handling to the generic functions and
removes the ldbl-128ibm versions.
Tested for powerpc32 (compared test-ldouble.out before and after the
changes; there are slight changes to results for ctanl / ctanhl,
arising from divergence of the implementations, but nothing that
affects the overall nature of the issues shown by the testsuite, and
in particular nothing related to signs of zero resutls).
* math/s_ctanhl.c [LDBL_MANT_DIG == 106] (LDBL_EPSILON): Undefine
and redefine.
* math/s_ctanl.c [LDBL_MANT_DIG == 106] (LDBL_EPSILON): Undefine
and redefine.
* sysdeps/ieee754/ldbl-128ibm/s_cprojl.c: Remove file.
* sysdeps/ieee754/ldbl-128ibm/s_ctanhl.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_ctanl.c: Likewise.
The ldbl-128 and ldbl-128ibm implementations of tanl produce
uninitialized variable warnings with -Wuninitialized because of a
variable that is initialized only conditionally, then used under the
same conditions under which it is set. This patch uses DIAG_* macros
to suppress those warnings.
Tested for powerpc and mips64.
* sysdeps/ieee754/ldbl-128/k_tanl.c: Include <libc-internal.h>.
(__kernel_tanl): Ignore uninitialized warnings around use of SIGN.
* sysdeps/ieee754/ldbl-128ibm/k_tanl.c: Include <libc-internal.h>.
(__kernel_tanl): Ignore uninitialized warnings around use of SIGN.
The ldbl-128 and ldbl-128ibm implementations of erfcl produce
uninitialized variable warnings with -Wuninitialized because of switch
statements where in fact one of the cases will always be executed, but
the compiler does not see that these cases cover all possibilities
(and because the reasoning that it does involves inequalities on the
representation of a floating point value leading to a set of possible
values for 8.0 times that value, converted to int, it's highly
nontrivial for the compiler to see that). This patch fixes those
warnings by converting the last case in those switch statements to a
"default" case.
Tested for powerpc and mips64.
* sysdeps/ieee754/ldbl-128/s_erfl.c (__erfcl): Make case 9 in
switch statement into default case.
* sysdeps/ieee754/ldbl-128ibm/s_erfl.c (__erfcl): Likewise.
The ldbl-128 and ldbl-128ibm implementations of asinl produce
uninitialized variable warnings with -Wuninitialized because the code
for small arguments in fact always returns but the compiler cannot see
this and instead sees that a variable would be uninitialized if the
"if (huge + x > one)" conditional used to force the "inexact"
exception were false.
All the code in libm trying to force "inexact" for functions that are
not exactly defined is suspect and should be removed at some point
given that we now have a clear definition of the accuracy goals for
libm functions which, following C99/C11, does not require anything
about "inexact" for most functions (likewise, the multi-precision code
that tries to give correctly-rounded results, very slowly, for
functions for which the goals clearly do not include correct rounding,
if the faster paths are accurate enough). However, for now this patch
simply changes the code to use math_force_eval, rather than "if", to
ensure the evaluation of the inexact computation.
Tested for powerpc and mips64.
* sysdeps/ieee754/ldbl-128/e_asinl.c (__ieee754_asinl): Don't use
a conditional in forcing "inexact".
* sysdeps/ieee754/ldbl-128ibm/e_asinl.c (__ieee754_asinl):
Likewise.
If you remove the "override CFLAGS += -Wno-uninitialized" in
math/Makefile, you get errors from lgamma implementations of the form:
../sysdeps/ieee754/dbl-64/e_lgamma_r.c: In function '__ieee754_lgamma_r':
../sysdeps/ieee754/dbl-64/e_lgamma_r.c:297:13: error: 'nadj' may be used uninitialized in this function [-Werror=maybe-uninitialized]
if(hx<0) r = nadj - r;
This is one of the standard kinds of false positive uninitialized
warnings: nadj is set under a certain condition, and then later used
under the same condition. This patch uses DIAG_* macros to suppress
the warning on the use of nadj. The ldbl-128 / ldbl-128ibm
implementation has a substantially different structure that avoids
this issue.
Tested for x86_64. (In fact this patch eliminates the need for that
-Wno-uninitialized on x86_64, but I want to test on more architectures
before removing it.)
* sysdeps/ieee754/dbl-64/e_lgamma_r.c: Include <libc-internal.h>.
(__ieee754_lgamma_r): Ignore uninitialized warnings around use of
NADJ.
* sysdeps/ieee754/flt-32/e_lgammaf_r.c: Include <libc-internal.h>.
(__ieee754_lgammaf_r): Ignore uninitialized warnings around use of
NADJ.
* sysdeps/ieee754/ldbl-96/e_lgammal_r.c: Include <libc-internal.h>.
(__ieee754_lgammal_r): Ignore uninitialized warnings around use of
NADJ.
If you remove the "override CFLAGS += -Wno-uninitialized" in
math/Makefile, one of the errors you get is:
../sysdeps/ieee754/dbl-64/mpa.c: In function '__mp_dbl.part.0':
../sysdeps/ieee754/dbl-64/mpa.c:183:5: error: 'c' may be used uninitialized in this function [-Werror=maybe-uninitialized]
c *= X[0];
The problem is that the p < 5 case initializes c if p is 1, 2, 3 or 4
but not otherwise, and in fact p is positive for all calls to this
function so the uninitialized case can't actually occur. This patch
replaces the "if (p == 4)" last case with a comment so the compiler
can see that all paths do initialize c.
Tested for x86_64.
* sysdeps/ieee754/dbl-64/mpa.c (norm): Remove if condition on
(p == 4) case.
ldbl-96 remquol wrongly handles the case where the first argument is
finite and the second infinite, because the check for the second
argument being a NaN fails to disregard the explicit high mantissa bit
and so wrongly interprets an infinity as being a NaN. This patch
fixes this by masking off that bit, and improves test coverage for
both remainder and remquo (various cases were missing tests, or, as in
the case of the bug, were tested only for one of the two functions).
Tested for x86_64 and x86.
[BZ #18244]
* sysdeps/ieee754/ldbl-96/s_remquol.c (__remquol): Ignore explicit
high mantissa bit when testing whether P is a NaN.
* math/libm-test.inc (remainder_test_data): Add more tests.
(remquo_test_data): Likewise.
Similar to various other bugs in this area, some atanh implementations
do not raise the underflow exception for subnormal arguments, when the
result is tiny and inexact. This patch forces the exception in a
similar way to previous fixes. (No change in this regard is needed
for the i386 implementation; special handling to force underflows in
these cases will only be needed there when the spurious underflows,
bug 18049, get fixed.)
Tested for x86_64, x86, powerpc and mips64.
[BZ #16352]
* sysdeps/i386/fpu/e_atanh.S (dbl_min): New object.
(__ieee754_atanh): Force underflow exception for results with
small absolute value.
* sysdeps/i386/fpu/e_atanhf.S (flt_min): New object.
(__ieee754_atanhf): Force underflow exception for results with
small absolute value.
* sysdeps/ieee754/dbl-64/e_atanh.c: Include <float.h>.
(__ieee754_atanh): Force underflow exception for results with
small absolute value.
* sysdeps/ieee754/flt-32/e_atanhf.c: Include <float.h>.
(__ieee754_atanhf): Force underflow exception for results with
small absolute value.
* sysdeps/ieee754/ldbl-128/e_atanhl.c: Include <float.h>.
(__ieee754_atanhl): Force underflow exception for results with
small absolute value.
* sysdeps/ieee754/ldbl-128ibm/e_atanhl.c: Include <float.h>.
(__ieee754_atanhl): Force underflow exception for results with
small absolute value.
* sysdeps/ieee754/ldbl-96/e_atanhl.c: Include <float.h>.
(__ieee754_atanhl): Force underflow exception for results with
small absolute value.
* math/auto-libm-test-in: Do not allow missing underflow
exceptions from atanh.
* math/auto-libm-test-out: Regenerated.
The flt-32 implementation of tanf produces spurious underflow
exceptions for some small arguments, through computing values on the
order of x^5. This patch fixes this by adjusting the threshold for
returning x (or, as applicable, +/- 1/x) to 2**-13 (the next term in
the power series being x^3/3).
Tested for x86_64 and x86.
[BZ #18221]
* sysdeps/ieee754/flt-32/k_tanf.c (__kernel_tanf): Use 2**-13 not
2**-28 as threshold for returning x or +/- 1/x.
* math/auto-libm-test-in: Add more tests of tan.
* math/auto-libm-test-out: Regenerated.
The flt-32 implementation of lgammaf produces spurious underflow
exceptions for some large arguments, because of calculations involving
x^-2 multiplied by small constants. This patch fixes this by
adjusting the threshold for a simpler computation to 2**26 (the error
in the simpler computation is on the order of 0.5 * log (x), for a
result on the order of x * log (x)).
Tested for x86_64 and x86.
[BZ #18220]
* sysdeps/ieee754/flt-32/e_lgammaf_r.c (__ieee754_lgammaf_r): Use
2**26 not 2**58 as threshold for returning x * (log (x) - 1).
* math/auto-libm-test-in: Add another test of lgamma.
* math/auto-libm-test-out: Regenerated.
The flt-32 implementation of erfcf produces spurious underflow
exceptions for some arguments close to 0, because of calculations
squaring the argument and then multiplying by small constants. This
patch fixes this by adjusting the threshold for arguments for which
the result is so close to 1 that 1 - x will give the right result from
2**-56 to 2**-26. (If 1 - x * 2/sqrt(pi) were used, the errors would be
on the order of x^3 and a much larger threshold could be used.)
Tested for x86_64 and x86.
[BZ #18217]
* sysdeps/ieee754/flt-32/s_erff.c (__erfcf): Use 2**-26 not 2**-56
as threshold for returning 1 - x.
* math/auto-libm-test-in: Add more tests of erfc.
* math/auto-libm-test-out: Regenerated.
The sysdeps/ieee754/flt-32 version of atanf produces spurious
underflow exceptions for some large arguments, because of computations
that compute x^-4. This patch fixes this by adjusting the threshold
for large arguments (for which +/- pi/2 can just be returned, the
correct result being roughly +/- pi/2 - 1/x) from 2^34 to 2^25.
Tested for x86_64 and x86.
[BZ #18196]
* sysdeps/ieee754/flt-32/s_atanf.c (__atanf): Use 2^25 not 2^34 as
threshold for large arguments.
* math/auto-libm-test-in: Add another test of atan.
* math/auto-libm-test-out: Regenerated.
Similar to various other bugs in this area, some log1p implementations
do not raise the underflow exception for subnormal arguments, when the
result is tiny and inexact. This patch forces the exception in a
similar way to previous fixes. (The ldbl-128ibm implementation
doesn't currently need any change as it already generates this
exception, albeit through code that would generate spurious exceptions
in other cases; special code for this issue will only be needed there
when fixing the spurious exceptions.)
Tested for x86_64, x86, powerpc and mips64.
[BZ #16339]
* sysdeps/i386/fpu/s_log1p.S (dbl_min): New object.
(__log1p): Force underflow exception for results with small
absolute value.
* sysdeps/i386/fpu/s_log1pf.S (flt_min): New object.
(__log1pf): Force underflow exception for results with small
absolute value.
* sysdeps/ieee754/dbl-64/s_log1p.c: Include <float.h>.
(__log1p): Force underflow exception for results with small
absolute value.
* sysdeps/ieee754/flt-32/s_log1pf.c: Include <float.h>.
(__log1pf): Force underflow exception for results with small
absolute value.
* sysdeps/ieee754/ldbl-128/s_log1pl.c: Include <float.h>.
(__log1pl): Force underflow exception for results with small
absolute value.
* math/auto-libm-test-in: Do not allow missing underflow
exceptions from log1p.
* math/auto-libm-test-out: Regenerated.
The implementation of roundl for ldbl-128 involves undefined behavior
for arguments with exponents from 31 to 47 inclusive, from the shift:
u_int64_t i = -1ULL >> (j0 - 48);
For example, on mips64, this means roundl (0xffffffffffff.8p0L)
wrongly returns its argument, which is not an integer. A condition
checking for exponents < 31 should actually be checking for exponents
< 48, and this patch makes it do so. (That condition is for whether
the bit representing 0.5 is in the high 64-bit half of the
floating-point number. The value 31 might have arisen from an
incorrect conversion of the ldbl-96 version to handle ldbl-128.)
This was originally reported as a GCC libquadmath bug
<https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65757>.
Tested for mips64; also tested for x86_64 and x86 to make sure the new
tests pass there.
[BZ #18346]
* sysdeps/ieee754/ldbl-128/s_roundl.c (__roundl): Handle all
exponents less than 48 as cases where high part of mantissa needs
examining to determine whether argument is integral.
* math/libm-test.inc (round_test_data): Add more tests.
According to bug 6792, errno is not set to ERANGE/EDOM
by calling log1p/log1pf/log1pl with x = -1 or x < -1.
This patch adds a wrapper which sets errno in those cases
and returns the value of the existing __log1p function.
The log1p is now an alias to the wrapper function
instead of __log1p.
The files in sysdeps are reflecting these changes.
The ia64 implementation sets errno by itself,
thus the wrapper-file is empty.
The libm-test is adjusted for log1p-tests to check errno.
[BZ #6792]
* math/w_log1p.c: New file.
* math/w_log1pf.c: Likewise.
* math/w_log1pl.c: Likewise.
* math/Makefile (libm-calls): Add w_log1p.
* math/s_log1pl.c (log1pl): Remove weak_alias.
* sysdeps/i386/fpu/s_log1p.S (log1p): Likewise.
* sysdeps/i386/fpu/s_log1pf.S (log1pf): Likewise.
* sysdeps/i386/fpu/s_log1pl.S (log1pl): Likewise.
* sysdeps/x86_64/fpu/s_log1pl.S (log1pl): Likewise.
* sysdeps/ieee754/dbl-64/s_log1p.c (log1p): Likewise.
[NO_LONG_DOUBLE] (log1pl): Likewise.
* sysdeps/ieee754/flt-32/s_log1pf.c (log1pf): Likewise.
* sysdeps/ieee754/ldbl-128/s_log1pl.c (log1pl): Likewise.
* sysdeps/ieee754/ldbl-64-128/s_log1pl.c
(log1p): Remove long_double_symbol.
* sysdeps/ieee754/ldbl-128ibm/s_log1pl.c (log1pl): Likewise.
* sysdeps/ieee754/ldbl-64-128/w_log1pl.c: New file.
* sysdeps/ieee754/ldbl-128ibm/w_log1pl.c: Likewise.
* sysdeps/m68k/m680x0/fpu/s_log1p.c: Define empty weak_alias to
remove weak_alias for corresponding log1p function.
* sysdeps/m68k/m680x0/fpu/s_log1pf.c: Likewise.
* sysdeps/m68k/m680x0/fpu/s_log1pl.c: Likewise.
* sysdeps/ia64/fpu/w_log1p.c: New file.
* sysdeps/ia64/fpu/w_log1pf.c: Likewise.
* sysdeps/ia64/fpu/w_log1pl.c: Likewise.
* math/libm-test.inc (log1p_test_data): Add errno expectations.
The dbl-64 implementation of atan2 does computations that expect to
run in round-to-nearest mode, and in other modes the errors can
accumulate to more than the maximum accepted 9ulp. This patch makes
it use FE_TONEAREST internally, similar to other functions with such
issues. Tests that previously produced large errors are added for
atan2 and the closely related carg, clog and clog10 functions.
Tested for x86_64 and x86 and ulps updated accordingly.
[BZ #18210]
[BZ #18211]
* sysdeps/ieee754/dbl-64/e_atan2.c: Include <fenv.h>.
(__ieee754_atan2): Set FE_TONEAREST mode for internal
computations.
* math/auto-libm-test-in: Add more tests of atan2, carg, clog and
clog10.
* math/auto-libm-test-out: Regenerated.
* sysdeps/i386/fpu/libm-test-ulps: Update.
* sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
The dbl-64 implementation of atan does computations that expect to run
in round-to-nearest mode, and in other modes the errors can accumulate
to more than the maximum accepted 9ulp. This patch makes it use
FE_TONEAREST internally, similar to other functions with such issues.
Tested for x86_64 and x86; no ulps updates needed.
[BZ #18197]
* sysdeps/ieee754/dbl-64/s_atan.c: Include <fenv.h>.
(atan): Set FE_TONEAREST mode for internal computations.
* math/auto-libm-test-in: Add more tests of atan.
* math/auto-libm-test-out: Regenerated.
The threshold in ldbl-96 atanhl for when to return the argument,
0x1p-28, is a bit too big, and that in ldbl-128ibm atanhl is much too
big (the relevant condition being x^3/3 being < 0.5ulp of x),
resulting in errors a bit above the limits of those considered
acceptable in glibc in the ldbl-96 case, and in large errors in the
ldbl-128ibm case. This patch changes those implementations to use
more appropriate thresholds and adds tests around the thresholds for
various formats.
Tested for x86_64, x86 and powerpc. x86_64 and x86 ulps updated
accordingly.
[BZ #18046]
[BZ #18047]
* sysdeps/ieee754/ldbl-128ibm/e_atanhl.c (__ieee754_atanhl): Use
0x1p-56L as threshold for just returning the argument.
* sysdeps/ieee754/ldbl-96/e_atanhl.c (__ieee754_atanhl): Use
0x1p-32L as threshold for just returning the argument.
* math/auto-libm-test-in: Add more tests of atanh.
* math/auto-libm-test-out: Regenerated.
* sysdeps/i386/fpu/libm-test-ulps: Update.
* sysdeps/x86_64/fpu/libm-test-ulp: Likewise.
We want to avoid -Wno- options in makefiles as far as possible, by
cleaning up the underlying issues if possible or failing that by using
diagnostic pragmas. This patch eliminates the use of
-Wno-write-strings for sysdeps/ieee754/k_standard.c by using casts in
the source file to cast away const; those casts are encapsulated in a
macro that also deals with the choice of strings for float / double /
long double functions (for which the logic was previously replicated
many times).
Tested for x86_64; the only change to disassembly of installed
stripped shared libraries was a line number in an assertion.
* sysdeps/ieee754/k_standard.c (CSTR): New macro.
(__kernel_standard): Use CSTR macro when setting exc.name.
* sysdeps/ieee754/Makefile [$(subdir) = math]
(CFLAGS-k_standard.c): Remove variable.
math/Makefile currently has:
# The fdlibm code generates a lot of these warnings but is otherwise clean.
override CFLAGS += -Wno-uninitialized
This is of course undesirable; warnings should be disabled as narrowly
as possible. To remove this override, we need to fix files that
generate such warnings, or put warning-disabling pragmas in them.
This patch does so for Bessel function implementations, one of the
cases that have the warnings if the override is removed. The warnings
arise because functions set pointer variables p and q only for certain
values of the function argument, then use them unconditionally. As
the static functions in question only get called for arguments that
satisfy the last condition in the if/else chain, the natural fix is to
change the last "else if" to just "else", which this patch does. (The
ldbl-128 / ldbl-128ibm implementation of these functions is
substantially different and looks like it already does use "else" in
the last case in the nearest corresponding code.)
Tested for x86_64 and x86.
* sysdeps/ieee754/dbl-64/e_j0.c (pzero): Change last case for
setting p and q from "else if" to "else".
(qzero): Likewise.
* sysdeps/ieee754/dbl-64/e_j1.c (pone): Likewise.
(qone): Likewise.
* sysdeps/ieee754/flt-32/e_j0f.c (pzerof): Likewise.
(qzerof): Likewise.
* sysdeps/ieee754/flt-32/e_j1f.c (ponef): Likewise.
(qonef): Likewise.
* sysdeps/ieee754/ldbl-96/e_j0l.c (pzero): Likewise.
(qzero): Likewise.
* sysdeps/ieee754/ldbl-96/e_j1l.c (pone): Likewise.
(qone): Likewise.
The ldbl-128 and ldbl-128ibm implementations of acosl have similar
bugs, using a threshold of 0x1p-57L to determine when they just return
pi/2. Since the result pi/2 - asinl (x) is roughly pi/2 - x for small
x, the relevant cut-off is actually x being < 0.5ulp of 1. This patch
fixes the implementations to use that cut-off and adds tests of small
acos arguments.
Tested for powerpc and mips64. Also tested for x86_64 and x86; no
ulps updates needed.
[BZ #18038]
[BZ #18039]
* sysdeps/ieee754/ldbl-128/e_acosl.c (__ieee754_acosl): Only
return pi/2 for arguments below 0x1p-113L.
* sysdeps/ieee754/ldbl-128ibm/e_acosl.c (__ieee754_acosl): Only
return pi/2 for arguments below 0x1p-106L.
* math/auto-libm-test-in: Add more tests of acos.
* math/auto-libm-test-out: Regenerated.
Similar to various other bugs in this area, some asin implementations
do not raise the underflow exception for subnormal arguments, when the
result is tiny and inexact. This patch forces the exception in a
similar way to previous fixes.
Tested for x86_64, x86, powerpc and mips64.
[BZ #16351]
* sysdeps/i386/fpu/e_asin.S (dbl_min): New object.
(MO): New macro.
(__ieee754_asin): Force underflow exception for results with small
absolute value.
* sysdeps/i386/fpu/e_asinf.S (flt_min): New object.
(MO): New macro.
(__ieee754_asinf): Force underflow exception for results with
small absolute value.
* sysdeps/ieee754/dbl-64/e_asin.c: Include <float.h> and <math.h>.
(__ieee754_asin): Force underflow exception for results with small
absolute value.
* sysdeps/ieee754/flt-32/e_asinf.c: Include <float.h>.
(__ieee754_asinf): Force underflow exception for results with
small absolute value.
* sysdeps/ieee754/ldbl-128/e_asinl.c: Include <float.h>.
(__ieee754_asinl): Force underflow exception for results with
small absolute value.
* sysdeps/ieee754/ldbl-128ibm/e_asinl.c: Include <float.h>.
(__ieee754_asinl): Force underflow exception for results with
small absolute value.
* sysdeps/ieee754/ldbl-96/e_asinl.c: Include <float.h>.
(__ieee754_asinl): Force underflow exception for results with
small absolute value.
* sysdeps/x86_64/fpu/multiarch/e_asin.c [HAVE_FMA4_SUPPORT]:
Include <math.h>.
* math/auto-libm-test-in: Do not mark underflow exceptions as
possibly missing for bug 16351.
* math/auto-libm-test-out: Regenerated.
The ldbl-128ibm implementation of logbl produces incorrect results
when the high part of the argument is a power of 2 and the low part a
nonzero number with the opposite sign (and so the returned exponent
should be 1 less than that of the high part). For example, logbl
(0x1.ffffffffffffffp1L) returns 2 but should return 1. (This is
similar to (fixed) bug 16740 for frexpl, and (fixed) bug 18029 for
ilogbl.) This patch adds checks for that case.
Tested for powerpc.
[BZ #18030]
* sysdeps/ieee754/ldbl-128ibm/s_logbl.c (__logbl): Adjust exponent
of power of 2 down when low part has opposite sign.
* math/libm-test.inc (logb_test_data): Add more tests.
The ldbl-128ibm implementation of ilogbl produces incorrect results
when the high part of the argument is a power of 2 and the low part a
nonzero number with the opposite sign (and so the returned exponent
should be 1 less than that of the high part). For example, ilogbl
(0x1.ffffffffffffffp1L) returns 2 but should return 1. (This is
similar to (fixed) bug 16740 for frexpl, and bug 18030 for logbl.)
This patch adds checks for that case.
Tested for powerpc.
[BZ #18029]
* sysdeps/ieee754/ldbl-128ibm/e_ilogbl.c (__ieee754_ilogbl):
Adjust exponent of power of 2 down when low part has opposite
sign.
* math/libm-test.inc (ilogb_test_data): Add more tests.
The ldbl-128ibm implementation of asinhl uses cut-offs of 0x1p28 and
0x1p-29 to determine when to use simpler formulas that avoid possible
overflow / underflow. Both those cut-offs are inappropriate for this
format, resulting in large errors. This patch changes the code to use
more appropriate cut-offs of 0x1p56 and 0x1p-56, adding tests around
the cut-offs for various floating-point formats.
Tested for powerpc. Also tested for x86_64 and x86 and updated ulps.
[BZ #18020]
* sysdeps/ieee754/ldbl-128ibm/s_asinhl.c (__asinhl): Use 2**56 and
2**-56 not 2**28 and 2**-29 as thresholds for simpler formulas.
* math/auto-libm-test-in: Add more tests of asinh.
* math/auto-libm-test-out: Regenerated.
* sysdeps/i386/fpu/libm-test-ulps: Update.
* sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
The ldbl-128ibm implementation of acoshl uses a cut-off of 0x1p28 to
determine when to use log(x) + log(2) as a formula. That cut-off is
too small for this format, resulting in large errors. This patch
changes it to a more appropriate cut-off of 0x1p56, adding tests
around the cut-offs for various floating-point formats.
Tested for powerpc. Also tested for x86_64 and x86 and updated ulps.
[BZ #18019]
* sysdeps/ieee754/ldbl-128ibm/e_acoshl.c (__ieee754_acoshl): Use
2**56 not 2**28 as threshold for log (2x) formula.
* math/auto-libm-test-in: Add more tests of acosh.
* math/auto-libm-test-out: Regenerated.
* sysdeps/i386/fpu/libm-test-ulps: Update.
* sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
This patch fixes bug 15319, missing underflows from atan / atan2 when
the result of atan is very close to its small argument (or that of
atan2 is very close to the ratio of its arguments, which may be an
exact division).
The usual approach of doing an underflowing computation if the
computed result is subnormal is followed. For 32-bit x86, there are
extra complications: the inline __ieee754_atan2 in bits/mathinline.h
needs to be disabled for float and double because other libm functions
using it generally rely on getting proper underflow exceptions from
it, while the out-of-line functions have to remove excess range and
precision from the underflowing result so as to return an exact 0 in
the case where errno should be set for underflow to 0. (The failures
I saw without that are similar to those Carlos reported for other
functions, where I haven't seen a response to
<https://sourceware.org/ml/libc-alpha/2015-01/msg00485.html>
confirming if my diagnosis is correct. Arguably all libm functions
with float and double returns should remove excess range and
precision, but that's a separate matter.)
The x86_64 long double case reported in a comment in bug 15319 is not
a bug (it's an argument of LDBL_MIN, and x86_64 is an after-rounding
architecture so the correct IEEE result is not to raise underflow in
the given rounding mode, in addition to treating the result as an
exact LDBL_MIN being within the newly clarified documentation of
accuracy goals). I'm presuming that the fpatan instruction can be
trusted to raise appropriate exceptions when the (long double) result
underflows (after rounding) and so no changes are needed for x86 /
x86_64 long double functions here; empirically this is the case for
the cases covered in the testsuite, on my system.
Tested for x86_64, x86, powerpc and mips64. Only 32-bit x86 needs
ulps updates (for the changes to inlines meaning some functions no
longer get excess precision from their __ieee754_atan2* calls).
[BZ #15319]
* sysdeps/i386/fpu/e_atan2.S (dbl_min): New object.
(MO): New macro.
(__ieee754_atan2): For results with small absolute value, force
underflow exception and remove excess range and precision from
return value.
* sysdeps/i386/fpu/e_atan2f.S (flt_min): New object.
(MO): New macro.
(__ieee754_atan2f): For results with small absolute value, force
underflow exception and remove excess range and precision from
return value.
* sysdeps/i386/fpu/s_atan.S (dbl_min): New object.
(MO): New macro.
(__atan): For results with small absolute value, force underflow
exception and remove excess range and precision from return value.
* sysdeps/i386/fpu/s_atanf.S (flt_min): New object.
(MO): New macro.
(__atanf): For results with small absolute value, force underflow
exception and remove excess range and precision from return value.
* sysdeps/ieee754/dbl-64/e_atan2.c: Include <float.h> and
<math.h>.
(__ieee754_atan2): Force underflow exception for results with
small absolute value.
* sysdeps/ieee754/dbl-64/s_atan.c: Include <float.h> and
<math_private.h>.
(atan): Force underflow exception for results with small absolute
value.
* sysdeps/ieee754/flt-32/s_atanf.c: Include <float.h>.
(__atanf): Force underflow exception for results with small
absolute value.
* sysdeps/ieee754/ldbl-128/s_atanl.c: Include <float.h> and
<math.h>.
(__atanl): Force underflow exception for results with small
absolute value.
* sysdeps/ieee754/ldbl-128ibm/s_atanl.c: Include <float.h>.
(__atanl): Force underflow exception for results with small
absolute value.
* sysdeps/x86/fpu/bits/mathinline.h
[!__SSE2_MATH__ && !__x86_64__ && __LIBC_INTERNAL_MATH_INLINES]
(__ieee754_atan2): Only define inline for long double.
* sysdeps/x86_64/fpu/multiarch/e_atan2.c
[HAVE_FMA4_SUPPORT || HAVE_AVX_SUPPORT]: Include <math.h>.
* math/auto-libm-test-in: Do not mark underflow exceptions as
possibly missing for bug 15319. Add more tests of atan2.
* math/auto-libm-test-out: Regenerated.
* math/libm-test.inc (casin_test_data): Do not mark underflow
exceptions as possibly missing for bug 15319.
(casinh_test_data): Likewise.
* sysdeps/i386/fpu/libm-test-ulps: Update.
Various remquo implementations produce a zero remainder with the wrong
sign (a zero remainder should always have the sign of the first
argument, as specified in IEEE 754) in round-downward mode, resulting
from the sign of 0 - 0. This patch checks for zero results and fixes
their sign accordingly.
Tested for x86_64, x86, mips64 and powerpc.
[BZ #17987]
* sysdeps/ieee754/dbl-64/s_remquo.c (__remquo): Ensure sign of
zero result does not depend on the sign resulting from
subtraction.
* sysdeps/ieee754/dbl-64/wordsize-64/s_remquo.c (__remquo):
Likewise.
* sysdeps/ieee754/flt-32/s_remquof.c (__remquof): Likewise.
* sysdeps/ieee754/ldbl-128/s_remquol.c (__remquol): Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_remquol.c (__remquol): Likewise.
* sysdeps/ieee754/ldbl-96/s_remquol.c (__remquol): Likewise.
* math/libm-test.inc (remquo_test_data): Add more tests.
Various remquo implementations, when computing the last three bits of
the quotient, have spurious overflows when 4 times the second argument
to remquo overflows. These overflows can in turn cause bad results in
rounding modes where that overflow results in a finite value. This
patch adds tests to avoid the problem multiplications in cases where
they would overflow, similar to those that control an earlier
multiplication by 8.
Tested for x86_64, x86, mips64 and powerpc.
[BZ #17978]
* sysdeps/ieee754/dbl-64/s_remquo.c (__remquo): Do not form
products 4 * y and 2 * y where those would overflow.
* sysdeps/ieee754/dbl-64/wordsize-64/s_remquo.c (__remquo):
Likewise.
* sysdeps/ieee754/flt-32/s_remquof.c (__remquof): Likewise.
* sysdeps/ieee754/ldbl-128/s_remquol.c (__remquol): Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_remquol.c (__remquol): Likewise.
* sysdeps/ieee754/ldbl-96/s_remquol.c (__remquol): Likewise.
* math/libm-test.inc (remquo_test_data): Add more tests.
The dbl-64/wordsize-64 remquo implementation follows similar logic to
various other implementations, but where that logic computes some
absolute values, it wrongly uses a previously computed bit-pattern for
the absolute value of the first argument, where actually it needs the
absolute value of the first argument mod 8 times the second. This
patch fixes it to compute the correct absolute value.
The integer quotient result of remquo is only specified mod 8
(including its sign); architecture-specific versions may well vary in
what results they give for higher bits of that result (and indeed bug
17569 gives an example correct result from __builtin_remquo giving 9
for that result, where the particular glibc implementation used in
that bug report would give 1 after this fix). Thus, this patch adapts
the tests of remquo to test that result only mod 8, to allow for such
variation when tests with higher quotient are included.
Tested for x86_64 and x86.
[BZ #17569]
* sysdeps/ieee754/dbl-64/wordsize-64/s_remquo.c (__remquo):
Compute absolute value of x as modified by fmod, not original
value of x.
* math/libm-test.inc (RUN_TEST_ffI_f1): Rename to
RUN_TEST_ffI_f1_mod8. Check extra return value mod 8.
(RUN_TEST_LOOP_ffI_f1): Rename to RUN_TEST_LOOP_ffI_f1_mod8. Call
RUN_TEST_ffI_f1_mod8.
(remquo_test_data): Add more tests.
This patch fixes the remaining part of bug 16560, spurious underflows
from exp2 of arguments close to 0 (when the result is close to 1, so
should not underflow), by just using 1+x instead of a more complicated
calculation when the argument is sufficiently small.
Tested for x86_64, x86 and mips64.
[BZ #16560]
* math/e_exp2l.c [LDBL_MANT_DIG == 106] (LDBL_EPSILON): Undefine
and redefine.
(__ieee754_exp2l): Do not multiply small fractional parts by
M_LN2l.
* sysdeps/i386/fpu/e_exp2l.S (__ieee754_exp2l): Just add 1 to
small argument.
* sysdeps/ieee754/dbl-64/e_exp2.c (__ieee754_exp2): Likewise.
* sysdeps/ieee754/flt-32/e_exp2f.c (__ieee754_exp2f): Likewise.
* sysdeps/x86_64/fpu/e_exp2l.S (__ieee754_exp2l): Likewise.
* math/auto-libm-test-in: Add more tests of exp2.
* math/auto-libm-test-out: Regenerated.
This patch makes sincos set errno to EDOM when passed an infinity,
similarly to sin and cos.
Tested for x86_64, x86, powerpc and mips64. I don't know if the
architecture-specific implementations for ia64 and m68k might need
corresponding fixes.
2015-02-11 Joseph Myers <joseph@codesourcery.com>
[BZ #15467]
* sysdeps/ieee754/dbl-64/s_sincos.c: Include <errno.h>.
(__sincos): Set errno to EDOM for infinite argument.
* sysdeps/ieee754/flt-32/s_sincosf.c: Include <errno.h>.
(SINCOSF_FUNC): Set errno to EDOM for infinite argument.
* sysdeps/ieee754/ldbl-128/s_sincosl.c: Include <errno.h>.
(__sincosl): Set errno to EDOM for infinite argument.
* sysdeps/ieee754/ldbl-128ibm/s_sincosl.c: Include <errno.h>.
(__sincosl): Set errno to EDOM for infinite argument.
* sysdeps/ieee754/ldbl-96/s_sincosl.c: Include <errno.h>.
(__sincosl): Set errno to EDOM for infinite argument.
* math/libm-test.inc (sincos_test_data): Test errno setting.
The ldbl-96 implementation of scalblnl (used for x86_64 and ia64) uses
a condition k <= -63 to determine when a standard underflowing result
tiny*__copysignl(tiny,x) should be returned. However, that condition
corresponds to values with exponent -16446 or less, and in the case of
-16446, the correct result for round-to-nearest depends on whether the
value is exactly 0x1p-16446 (half the least subnormal) or more than
that. This patch fixes the bug by changing the condition to k <= -64
and accordingly adjusting the exponent by 64 not 63 when converting to
a normal value.
Tested for x86_64.
[BZ #17803]
* sysdeps/ieee754/ldbl-96/s_scalblnl.c (twom63): Rename to
twom64. Adjust value to 0x1p-64L.
(__scalblnl): Only return standard underflowing result for K <=
-64 not K <= -63; adjust exponent for underflowing result by 64
not 63.
* math/libm-test.inc (scalbn_test_data): Add more tests.
(scalbln_test_data): Likewise.
The ldbl-96 implementation of scalblnl (used for x86_64 and ia64) is
incorrect for subnormal arguments (this is a separate bug from bug
17803, which is about underflowing results). There are two problems
with the adjustments of subnormal arguments: the "two63" variable
multiplied by is actually 0x1p52L not 0x1p63L, so is insufficient to
make values normal, and then GET_LDOUBLE_EXP(es,x), used to extract
the new exponent, extracts it into a variable that isn't used, while
the value taken to by the new exponent is wrongly taken from the high
part of the mantissa before the adjustment (hx). This patch fixes
both those problems and adds appropriate tests.
Tested for x86_64.
[BZ #17834]
* sysdeps/ieee754/ldbl-96/s_scalblnl.c (two63): Change value to
0x1p63L.
(__scalblnl): Get new exponent of adjusted subnormal value from ES
not HX.
* math/libm-test.inc (scalbn_test_data): Add more tests.
(scalbln_test_data): Likewise.
Platforms with 64-bit registers where 32-bit values need to have the
high 32 bits set in a particular way need to have an explicit cast
when using the 64-bit sysdeps/ieee754/dbl-64/wordsize-64 version
of llround() as lround(). This includes tilegx32, and likely MIPS.
x32 does not need this, and AArch64 ILP32 will not either. Require
it to be specified in sysdep.h to be explicit.
