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.
This patch adds more tests of lrint, llrint, lround and llround, to
cover various standard special cases not previously covered, and more
tests of overflow.
Tested for x86_64 and x86.
* math/libm-test.inc (lrint_test_data): Add more tests.
(llrint_test_data): Likewise.
(lround_test_data): Likewise.
(llround_test_data): Likewise.
This patch makes lrint and llrint use the same test inputs in
libm-test.inc, appropriately conditioned on LONG_MAX in the lrint
case.
Tested for x86_64 and x86.
* math/libm-test.inc (lrint_test_data): Add tests used for llrint.
(llrint_test_data): Add tests used for lrint.
GCC added support for -msse4 in version 4.3. Thus the configure tests
for it are obsolete, and this patch removes them.
Tested for x86_64 and x86 (testsuite, and that installed stripped
shared libraries are unchanged by this patch).
* sysdeps/i386/configure.ac (libc_cv_cc_sse4): Remove configure
test.
* sysdeps/i386/configure: Regenerated.
* sysdeps/i386/i686/multiarch/Makefile
[$(config-cflags-sse4) = yes]: Make code unconditional.
* sysdeps/i386/i686/multiarch/strcspn.S [HAVE_SSE4_SUPPORT]:
Likewise.
* sysdeps/i386/i686/multiarch/strspn.S [HAVE_SSE4_SUPPORT]:
Likewise.
* sysdeps/x86_64/configure.ac (libc_cv_cc_sse4): Remove configure
test.
* sysdeps/x86_64/configure: Regenerated.
* sysdeps/x86_64/multiarch/Makefile [$(config-cflags-sse4) = yes]:
Make code unconditional.
* sysdeps/x86_64/multiarch/strcspn.S [HAVE_SSE4_SUPPORT]:
Likewise.
* sysdeps/x86_64/multiarch/strspn.S [HAVE_SSE4_SUPPORT]: Likewise.
* config.h.in (HAVE_SSE4_SUPPORT): Remove #undef.
The file scripts/rpm2dynsym.sh appears to be unused anywhere in glibc.
This patch removes this script.
Tested for x86_64 and x86 (testsuite, and that installed shared
libraries are unchanged by the patch).
* scripts/rpm2dynsym.sh: Remove file.
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.
This patch adds more libm-test.inc expectations for the "inexact"
exception for scalb, in all cases except those with a non-integer
second argument (where results are unspecified by POSIX, so the
function does not count as fully determined and the spurious "inexact"
exceptions raised by the existing implementations alongside "invalid"
are OK).
Tested for x86_64 and x86.
* math/libm-test.inc (scalb_test_data): Add more expectations for
the "inexact" exception.
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 recent put*ent hardening changes broke the build for i386. i386
defines internal_function to __attribute__ ((regparm (3), stdcall)),
which affects type compatibility, so requiring internal_function to be
used consistently on declarations and definitions. This patch adds
internal_function to the definitions of the new functions using it on
their declarations.
Tested for i386 that this fixes the build.
* nss/rewrite_field.c (__nss_rewrite_field): Use
internal_function.
* nss/valid_field.c (__nss_valid_field): Likewise.
* nss/valid_list_field.c (__nss_valid_list_field): Likewise.
This prevents injection of ':' and '\n' into output functions which
use the NSS files database syntax. Critical fields (user/group names
and file system paths) are checked strictly. For backwards
compatibility, the GECOS field is rewritten instead.
The getent program is adjusted to use the put*ent functions in libc,
instead of local copies. This changes the behavior of getent if user
names start with '-' or '+'.
The file sysdeps/powerpc/sysdeps.h defines aliases for register operands,
which add the letter 'r' as a prefix to a register name. E.g.: register 20
can be written as 'r20', instead of '20'. On the one hand, this increases
readability, as it makes it easier for readers to know whether the operand is a
register or an immediate. On the other hand, this permits that immediate
operands be written as if they were registers, and vice-versa, thus reducing
the readability of the code.
This commit removes some of these unintentional misuses.
This commit also increases readability of the code by adding the prefix 'cr' to
some uses of the control register.
Both changes have no effect on the final code. Checked with objdump.
* sysdeps/powerpc/powerpc64/power8/strncpy.S: Remove or add register
prefix from operands.
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.
When libm-test.inc prints the results of failing tests, the output can
be unhelpful for ldbl-128 and ldbl-128ibm because the precision used
is insufficient to distinguish values of those types, resulting in
reported values that look identical but differ by a large number of
ulps.
This patch changes it to use a precision appropriate for the type, for
both decimal and hex output (so output for float is more compact,
output for ldbl-128 and ldbl-128ibm is substantially wider). The
natural precision to use for decimal is given by the C11 <float.h>
macros such as FLT_DECIMAL_DIG. GCC's <float.h> only defines those in
C11 mode, so this patch uses the predefines such as
__FLT_DECIMAL_DIG__ (added in GCC 4.6) instead; if we move to building
with -std=gnu11 (or -std=gnu1x if we can't get rid of 4.6 support).
Tested for powerpc and mips64.
* math/libm-test.inc (TYPE_DECIMAL_DIG): New macro.
(TYPE_HEX_DIG): Likewise.
(print_float): Use TYPE_DECIMAL_DIG - 1 and TYPE_HEX_DIG - 1 as
precisions when printing floating-point numbers.
(check_float_internal): Likewise.
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).
The i386 versions of acoshf and acosh raise a spurious "invalid"
exception for an argument that is a quiet NaN with the sign bit set.
The integer arithmetic to detect arguments < 1 also detects -NaN, and
then the computation 0 / 0 in that case raises the exception. This
patch fixes this by using (x - x) / (x - x) as the computation in that
case instead, which will always raise the exception for non-NaN
arguments reaching that code, but not for quiet NaN arguments.
Tested for x86_64 and x86.
[BZ #19032]
* sysdeps/i386/fpu/e_acosh.S (__ieee754_acosh): For arguments < 1,
compute result as (x - x) / (x - x) not as 0 / 0.
* sysdeps/i386/fpu/e_acoshf.S (__ieee754_acoshf): Likewise.
* math/libm-test.inc (acosh_test_data): Add another test of acosh.
This patch improves test coverage of the real libm functions [a-e]*,
ensuring that special cases and ranges of input values of potential
significance (such as close to overflow and underflow thresholds) are
more systematically covered.
This is a followup to
<https://sourceware.org/ml/libc-alpha/2013-12/msg00757.html> which
covered [a-c]* (however, I found more weaknesses in the coverage of
those functions when preparing this patch, hence the additional tests
being added for them here).
Addition of a test for acosh (-qNaN) is temporarily deferred, to be
included as part of a fix for bug 19032 which was discovered in the
course of adding these tests (and which illustrates the use of testing
-qNaN as well as +qNaN as input even to functions for which the sign
of a NaN isn't meant to be significant).
Tested for x86_64 and x86.
* math/auto-libm-test-in: Add more tests of acos, acosh, asin,
atan, atan2, atanh, cbrt, cos, cosh, erf, erfc, exp, exp10, exp2
and expm1.
* math/auto-libm-test-out: Regenerated.
* math/libm-test.inc (acos_test_data): Add more tests.
(asin_test_data): Likewise.
(asinh_test_data): Likewise.
(atan_test_data): Likewise.
(atanh_test_data): Likewise.
(atan2_test_data): Likewise.
(cbrt_test_data): Likewise.
(ceil_test_data): Likewise.
(copysign_test_data): Likewise.
(cos_test_data): Likewise.
(cosh_test_data): Likewise.
(erf_test_data): Likewise.
(erfc_test_data): Likewise.
(exp_test_data): Likewise.
(exp10_test_data): Likewise.
(exp2_test_data): Likewise.
(expm1_test_data): Likewise.
* sysdeps/x86_64/fpu/libm-test-ulps: Update.
This patch makes math/libm-test.inc more consistent regarding
including expectations for errno setting and "inexact" exceptions
where expected test results are given manually. Mostly this is a
matter of including ERRNO_UNCHANGED in expectations, but there are
also some cases where expectations regarding "inexact" were missing
for exactly determined functions (especially in cases where some other
exception was expected and it should also have been expected that
"inexact" was not set with that other exception), and one case for pow
where the NO_INEXACT_EXCEPTION expectation should not have been there
(the rule about not having "inexact" exceptions for NaN arguments is
only when those NaN arguments produce NaN results).
I deferred making such changes for complex functions and scalb.
Tested for x86_64 and x86.
* math/libm-test.inc (acos_test_data): Refine expectations for
errno and "inexact" exceptions.
(acosh_test_data): Likewise.
(asin_test_data): Likewise.
(asinh_test_data): Likewise.
(atan_test_data): Likewise.
(atanh_test_data): Likewise.
(atan2_test_data): Likewise.
(cbrt_test_data): Likewise.
(ceil_test_data): Likewise.
(copysign_test_data): Likewise.
(cosh_test_data): Likewise.
(erf_test_data): Likewise.
(erfc_test_data): Likewise.
(exp_test_data): Likewise.
(exp10_test_data): Likewise.
(exp2_test_data): Likewise.
(expm1_test_data): Likewise.
(fabs_test_data): Likewise.
(floor_test_data): Likewise.
(fma_test_data): Likewise.
(fmax_test_data): Likewise.
(fmin_test_data): Likewise.
(fmod_test_data): Likewise.
(fpclassify_test_data): Likewise.
(frexp_test_data): Likewise.
(hypot_test_data): Likewise.
(ilogb_test_data): Likewise.
(isgreater_test_data): Likewise.
(isgreaterequal_test_data): Likewise.
(isinf_test_data): Likewise.
(isless_test_data): Likewise.
(islessequal_test_data): Likewise.
(islessgreater_test_data): Likewise.
(isnan_test_data): Likewise.
(isnormal_test_data): Likewise.
(issignaling_test_data): Likewise.
(isunordered_test_data): Likewise.
(j0_test_data): Likewise.
(j1_test_data): Likewise.
(jn_test_data): Likewise.
(lgamma_test_data): Likewise.
(lrint_test_data): Likewise.
(llrint_test_data): Likewise.
(log_test_data): Likewise.
(log10_test_data): Likewise.
(log1p_test_data): Likewise.
(log2_test_data): Likewise.
(logb_test_data): Likewise.
(lround_test_data): Likewise.
(llround_test_data): Likewise.
(modf_test_data): Likewise.
(nearbyint_test_data): Likewise.
(nextafter_test_data): Likewise.
(nexttoward_test_data): Likewise.
(pow_test_data): Likewise.
(remainder_test_data): Likewise.
(remquo_test_data): Likewise.
(rint_test_data): Likewise.
(round_test_data): Likewise.
(signbit_test_data): Likewise.
(sinh_test_data): Likewise.
(sqrt_test_data): Likewise.
(tanh_test_data): Likewise.
(tgamma_test_data): Likewise.
(trunc_test_data): Likewise.
(y0_test_data): Likewise.
(y1_test_data): Likewise.
(yn_test_data): Likewise.
(significand_test_data): Likewise.
In the posix_fallocate description in the manual we list various
drawbacks with the emulation, including the fact that a file opened
with O_APPEND fails with EBADF. Similarly a file opened with O_WRONLY
fails with EBADF. We must be able to emulate a compare-and-swap via
pread/compare/pwrite in order to make the emulation as safe as possible.
It is not acceptable to ignore the read failure because it could result
in significant data loss across all of the blocks. There is no other way
to make this work without a true atomic CAS and SIGBUS handler (which
is looking more attractive as a way to remove the race condition).
This patch adds O_WRONLY to the manual as another bullet to clarify the
limits of the emulation.
Manual looks good in PDF.
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.
It used to be common practice to have a statically linked shell for an
alternative root account, as in:
root❌0:0:root:/root:/bin/bash
toor❌0:0:root recovery account:/root:/sbin/sash
This causes problems with passwd NSS tests because a UID-based lookup
will only retrieve one of those entries. The original version of
nss/bug17079.c detected this, but failed to use this information later
on.
Systems without floating-point exceptions and rounding modes should
use the soft-fp versions of fmaf and fma, not the sysdeps/ieee754
versions that rely on setting rounding to zero and testing for the
"inexact" exception; this has been noted on
<https://sourceware.org/glibc/wiki/PortStatus> for some time. This
patch makes no-FPU ColdFire use the soft-fp files; sfp-machine.h is
made to include the nios2 version of sfp-machine.h which seems
sufficiently generic for 32-bit systems.
[BZ #13304]
* sysdeps/m68k/coldfire/nofpu/s_fma.c: New file.
* sysdeps/m68k/coldfire/nofpu/s_fmaf.c: Likewise.
* sysdeps/m68k/coldfire/nofpu/sfp-machine.h: Likewise.
Systems without floating-point exceptions and rounding modes should
use the soft-fp versions of fmaf and fma, not the sysdeps/ieee754
versions that rely on setting rounding to zero and testing for the
"inexact" exception; this has been noted on
<https://sourceware.org/glibc/wiki/PortStatus> for some time. This
patch makes MicroBlaze use the soft-fp files; sfp-machine.h is made to
include the nios2 version of sfp-machine.h which seems sufficiently
generic for 32-bit systems.
[BZ #13304]
* sysdeps/microblaze/s_fma.c: New file.
* sysdeps/microblaze/s_fmaf.c: Likewise.
* sysdeps/microblaze/sfp-machine.h: Likewise.
Fix a regression introduced with commit 0d23a5c1 [Static dlopen
correction fallout fixes] that caused the default library search path to
be ignored for modules loaded with dlopen from static executables.
[BZ #17250]
* elf/dl-support.c (_dl_main_map): Don't initialize l_flags_1
member.
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.
This patch refactors code in sysdeps/x86_64/fpu that forces underflow
exceptions and closely follows corresponding i386 code to use common
macros in x86_64-math-asm.h for that purpose. This is mainly about
keeping the code similar to the i386 code as far as possible, since
each macro apart from DEFINE_LDBL_MIN ends up used only once. It
would be possible to do a further refactoring to share these macros
between i386 and x86_64 (with i386 using the fcomip / fucomip versions
when building for i686 and above), but I have no immediate plans to do
so.
Tested for x86_64.
* sysdeps/x86_64/fpu/x86_64-math-asm.h: New file.
* sysdeps/x86_64/fpu/e_exp2l.S: Include <x86_64-math-asm.h>.
(ldbl_min): Replace with use of DEFINE_LDBL_MIN.
(__ieee754_exp2l): Use LDBL_CHECK_FORCE_UFLOW_NONNEG_NAN.
* sysdeps/x86_64/fpu/e_expl.S: Include <x86_64-math-asm.h>.
[!USE_AS_EXPM1L] (cmin): Replace with use of DEFINE_LDBL_MIN.
(IEEE754_EXPL): Use LDBL_CHECK_FORCE_UFLOW_NONNEG.
sysdeps/i386/fpu/e_atanh.S, unlike all other functions in that
directory, loads the PIC register with its own code using
_GLOBAL_OFFSET_TABLE_, rather than with the LOAD_PIC_REG macro. I see
no good reason for the difference; this patch makes it use the common
macro.
Tested for x86.
* sysdeps/i386/fpu/e_atanh.S (__ieee754_atanh) [PIC]: Use
LOAD_PIC_REG.
This patch refactors code in sysdeps/i386/fpu that forces underflow
exceptions to use common macros for that purpose as far as possible.
(Although some of the macros end up used in only one place, I think
it's cleanest to define all these macros together so that all the code
forcing underflow uses such macros. Some more uses of such macros
will also be introduced when fixing remaining bugs about missing
underflow exceptions, and it would be possible to do further
refactoring of the macros in i386-math-asm.h to share more code by
using other macros internally. Places that test for underflow by
examining the representation of the argument with integer operations,
rather that using floating-point comparisons on the argument or
result, are unchanged by this patch.)
Most of this code uses a macro MO to abstract away the differences
between PIC and non-PIC memory references to constants. log1p
functions, however, hardcoded PIC conditionals for this. Because the
common macros rely on the use of MO, I changed the log1p functions to
use the normal style here, and, for consistency, also made that change
to log1pl which is otherwise unaffected by this patch.
Tested for x86.
* sysdeps/i386/fpu/i386-math-asm.h (DEFINE_LDBL_MIN): New macro.
(FLT_CHECK_FORCE_UFLOW): Likewise.
(DBL_CHECK_FORCE_UFLOW): Likewise.
(FLT_CHECK_FORCE_UFLOW_NARROW): Likewise.
(DBL_CHECK_FORCE_UFLOW_NARROW): Likewise.
(LDBL_CHECK_FORCE_UFLOW_NONNEG_NAN): Likewise.
(FLT_CHECK_FORCE_UFLOW_NONNAN): Likewise.
(DBL_CHECK_FORCE_UFLOW_NONNAN): Likewise.
(FLT_CHECK_FORCE_UFLOW_NONNEG): Likewise.
(DBL_CHECK_FORCE_UFLOW_NONNEG): Likewise.
(LDBL_CHECK_FORCE_UFLOW_NONNEG): Likewise.
* sysdeps/i386/fpu/e_asin.S: Include <i386-math-asm.h>.
(dbl_min): Replace with use of DEFINE_DBL_MIN.
(__ieee754_asin): Use DBL_CHECK_FORCE_UFLOW.
* sysdeps/i386/fpu/e_asinf.S: Include <i386-math-asm.h>.
(flt_min): Replace with use of DEFINE_FLT_MIN.
(__ieee754_asinf): Use FLT_CHECK_FORCE_UFLOW.
* sysdeps/i386/fpu/e_atan2.S: Include <i386-math-asm.h>.
(dbl_min): Replace with use of DEFINE_DBL_MIN.
(__ieee754_atan2): Use DBL_CHECK_FORCE_UFLOW_NARROW.
* sysdeps/i386/fpu/e_atan2f.S: Include <i386-math-asm.h>.
(flt_min): Replace with use of DEFINE_FLT_MIN.
(__ieee754_atan2f): Use FLT_CHECK_FORCE_UFLOW_NARROW.
* sysdeps/i386/fpu/e_atanh.S: Include <i386-math-asm.h>.
(dbl_min): Replace with use of DEFINE_DBL_MIN.
(__ieee754_atanh): Use DBL_CHECK_FORCE_UFLOW_NONNEG.
* sysdeps/i386/fpu/e_atanhf.S: Include <i386-math-asm.h>.
(flt_min): Replace with use of DEFINE_FLT_MIN.
(__ieee754_atanhf): Use FLT_CHECK_FORCE_UFLOW_NONNEG.
* sysdeps/i386/fpu/e_exp2l.S: Include <i386-math-asm.h>.
(ldbl_min): Replace with use of DEFINE_LDBL_MIN.
(__ieee754_exp2l): Use LDBL_CHECK_FORCE_UFLOW_NONNEG_NAN.
* sysdeps/i386/fpu/e_expl.S: Include <i386-math-asm.h>.
[!USE_AS_EXPM1L] (cmin): Replace with use of DEFINE_LDBL_MIN.
(IEEE754_EXPL): Use LDBL_CHECK_FORCE_UFLOW_NONNEG.
* sysdeps/i386/fpu/s_atan.S: Include <i386-math-asm.h>.
(dbl_min): Replace with use of DEFINE_DBL_MIN.
(__atan): Use DBL_CHECK_FORCE_UFLOW.
* sysdeps/i386/fpu/s_atanf.S: Include <i386-math-asm.h>.
(flt_min): Replace with use of DEFINE_FLT_MIN.
(__atanf): Use FLT_CHECK_FORCE_UFLOW.
* sysdeps/i386/fpu/s_expm1.S: Include <i386-math-asm.h>.
(dbl_min): Replace with use of DEFINE_DBL_MIN.
(__expm1): Use DBL_CHECK_FORCE_UFLOW. Move underflow check after
main computation.
* sysdeps/i386/fpu/s_expm1f.S: Include <i386-math-asm.h>.
(flt_min): Replace with use of DEFINE_FLT_MIN.
(__expm1f): Use FLT_CHECK_FORCE_UFLOW. Move underflow check after
main computation.
* sysdeps/i386/fpu/s_log1p.S: Include <i386-math-asm.h>.
(dbl_min): Replace with use of DEFINE_DBL_MIN.
(MO): New macro.
(__log1p): Use MO. Use DBL_CHECK_FORCE_UFLOW_NONNAN.
* sysdeps/i386/fpu/s_log1pf.S: Include <i386-math-asm.h>.
(flt_min): Replace with use of DEFINE_FLT_MIN.
(MO): New macro.
(__log1pf): Use MO. Use FLT_CHECK_FORCE_UFLOW_NONNAN.
* sysdeps/i386/fpu/s_log1pl.S (MO): New macro.
(__log1pl): Use MO.
The x86_64 fma4 version of pow fails to disable contraction of
operations other than those explicitly intended to use fma
instructions, so resulting in large ulps errors on processors with
fma4 instructions, as in bug 18104 (165ulp for the test added for that
bug; error originally reported by "blaaa" on #glibc). This patch adds
$(config-cflags-nofma) for e_pow-fma4.c, corresponding to the use for
e_pow.c in sysdeps/ieee754/dbl-64/Makefile.
Tested for x86_64 on a processor with fma4.
[BZ #19003]
* sysdeps/x86_64/fpu/multiarch/Makefile (CFLAGS-e_pow-fma4.c): Add
$(config-cflags-nofma).
