The current approach tracks math maximum supported errors by explicitly
setting them per function and architecture. On newer implementations or
new compiler versions, the file is updated with newer values if it
shows higher results. The idea is to track the maximum known error, to
update the manual with the obtained values.
The constant libm-test-ulps shows little value, where it is usually a
mechanical change done by the maintainer, for past releases it is
usually ignored whether the ulp change resulted from a compiler
regression, and the math tests already have a maximum ulp error that
triggers a regression.
It was shown by a recent update after the new acosf [1] implementation
that is correctly rounded, where the libm-test-ulps was indeed from a
compiler issue.
This patch removes all arch-specific libm-test-ulps, adds system generic
libm-test-ulps where applicable, and changes its semantics. The generic
files now track specific implementation constraints, like if it is
expected to be correctly rounded, or if the system-specific has
different error expectations.
Now multiple libm-test-ulps can be defined, and system-specific
overrides generic implementation. This is for the case where
arch-specific implementation might show worse precision than generic
implementation, for instance, the cbrtf on i686.
Regressions are only reported if the implementation shows larger errors
than 9 ulps (13 for IBM long double) unless it is overridden by
libm-test-ulps and the maximum error is not printed at the end of tests.
The regen-ulps rule is also removed since it does not make sense to
update the libm-test-ulps automatically.
The manual error table is also removed, Paul Zimmermann and others have
been tracking libm precision with a more comprehensive analysis for some
releases; so link to his work instead.
[1] https://sourceware.org/git/?p=glibc.git;a=commit;h=9cc9f8e11e8fb8f54f1e84d9f024917634a78201
More routines are to follow, some of which hit many failures in the
current testsuite due to wrong sign of zero (mathvec routines are not
required to get this right). Instead of disabling a large number of
tests, change the failure condition such that, for vector routines,
tests pass as long as computed == expected == 0.0, regardless of sign.
Affected tests (vector tests for expm1, log1p, sin, tan and tanh) all
still pass.
Add support for a no-mathvec flag to gen-auto-libm-tests.c.
Update input test sin (-0.0) to be skipped in vector math libraries and
regenerate testcases.
Reviewed-By: Paul Zimmermann <Paul.Zimmermann@inria.fr>
I used these shell commands:
../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")
and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 7061 files FOO.
I then removed trailing white space from math/tgmath.h,
support/tst-support-open-dev-null-range.c, and
sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following
obscure pre-commit check failure diagnostics from Savannah. I don't
know why I run into these diagnostics whereas others evidently do not.
remote: *** 912-#endif
remote: *** 913:
remote: *** 914-
remote: *** error: lines with trailing whitespace found
...
remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
I used these shell commands:
../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")
and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 6694 files FOO.
I then removed trailing white space from benchtests/bench-pthread-locks.c
and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this
diagnostic from Savannah:
remote: *** pre-commit check failed ...
remote: *** error: lines with trailing whitespace found
remote: error: hook declined to update refs/heads/master
With mathinline removal there is no need to keep building and testing
inline math tests.
The gen-libm-tests.py support to generate ULP_I_* is removed and all
libm-test-ulps files are updated to longer have the
i{float,double,ldouble} entries. The support for no-test-inline is
also removed from both gen-auto-libm-tests and the
auto-libm-test-out-* were regenerated.
Checked on x86_64-linux-gnu and i686-linux-gnu.
Change all of the #! lines in Python scripts that are called from
Makefiles to reference /usr/bin/python3.
All of the scripts called from Makefiles are already run with Python 3,
so let's make sure they are explicitly using Python 3 if called
manually.
Remove the finite-math tests from the testsuite - these are no longer
useful after removing math-finite.h header.
Passes buildmanyglibc, build&test on x86_64 and AArch64.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This patch extends gen-libm-test.py to generate the ulps table for the
manual, so meaning there is only a single ulps file parser needed and
another Perl script is eliminated. As with the introduction of
gen-libm-test.py, this is designed to generate exactly the same
libm-err.texi as libm-err-tab.pl did. (gen-libm-test.py is still
shorter in lines than the old gen-libm-test.pl even after this patch.)
Note that this introduces a Python dependency for building the manual,
which is thus noted in install.texi and NEWS.
Tested building html / info / pdf versions of the manual.
* math/gen-libm-test.py: Import os.
(ALL_FLOATS_MANUAL): New constant.
(ALL_FLOATS_SUFFIX): Likewise.
(Ulps.all_functions): New function.
(real_all_ulps): Likewise.
(generate_err_table_sub): Likewise.
(generate_err_table): Likewise.
(main): Handle -s and -m options.
* manual/libm-err-tab.pl: Remove.
* manual/Makefile ($(objpfx)stamp-libm-err): Use gen-libm-test.py
instead of libm-err-tab.pl.
[$(PERL) != no]: Change condition to [$(if $(PYTHON),$(PERL),no)
!= no].
* manual/install.texi (Tools for Compilation): Document
requirement for Python to build manual.
* INSTALL: Regenerated.
When converting gen-libm-test to Python, in one place I noted a bug in
the old Perl version that I preserved in the Python version so that
the generated output files were the same with both versions, as such
comparisons help give confidence in the correctness of such a rewrite
of a script. Now that the conversion has been done, this patch fixes
that bug, by arranging for tests with plus_oflow or minus_oflow
results (manually written tests in libm-test-*.inc that have
overflowing results that thus depend on the rounding mode) to be
properly treated as having non-finite results, and thus not run for
the __FINITE_MATH_ONLY__ tests. (As the affected tests in fact did
pass for __FINITE_MATH_ONLY__ testing, this is just a matter of
logical correctness in the choice of which tests run for that case,
rather than fixing any actual test failures.)
Tested for x86_64.
* math/gen-libm-test.py (gen_test_args_res): Also treat plus_oflow
and minus_oflow as non-finite.
Following the recent discussion of using Python instead of Perl and
Awk for glibc build / test, this patch replaces gen-libm-test.pl with
a new gen-libm-test.py script. This script should work with all
Python versions supported by glibc (tested by hand with Python 2.7,
tested in the build system with Python 3.5; configure prefers Python 3
if available).
This script is designed to give identical output to gen-libm-test.pl
for ease of verification of the change, except for generated comments
referring to .py instead of .pl. (That is, identical for actual
inputs passed to the script, not necessarily for all possible input;
for example, this version more precisely follows the C standard syntax
for floating-point constants when deciding when to add LIT macro
calls.) In one place a comment notes that the generation of
NON_FINITE flags is replicating a bug in the Perl script to assist in
such comparisons (with the expectation that this bug can then be
separately fixed in the Python script later).
Tested for x86_64, including comparison of generated files (and hand
testing of the case of generating a sorted libm-test-ulps file, which
isn't covered by normal "make check").
I'd expect to follow this up by extending the new script to produce
the ulps tables for the manual as well (replacing
manual/libm-err-tab.pl, so that then we just have one ulps file
parser) - at which point the manual build would depend on both Perl
and Python (eliminating the Perl dependency would require someone to
rewrite summary.pl in Python, and that would only eliminate the
*direct* Perl dependency; current makeinfo is written in Perl so there
would still be an indirect dependency).
I think install.texi is more or less equally out-of-date regarding
Perl and Python uses before and after this patch, so I don't think
this patch depends on my patch
<https://sourceware.org/ml/libc-alpha/2018-08/msg00133.html> to update
install.texi regarding such uses (pending review).
* math/gen-libm-test.py: New file.
* math/gen-libm-test.pl: Remove.
* math/Makefile [$(PERL) != no]: Change condition to [PYTHON].
($(objpfx)libm-test-ulps.h): Use gen-libm-test.py instead of
gen-libm-test.pl.
($(libm-test-c-noauto-obj)): Likewise.
($(libm-test-c-auto-obj)): Likewise.
($(libm-test-c-narrow-obj)): Likewise.
(regen-ulps): Likewise.
* math/README.libm-test: Update references to gen-libm-test.pl.
* math/libm-test-driver.c (struct test_fj_f_data): Update comment
referencing gen-libm-test.pl.
* math/libm-test-nexttoward.inc (nexttoward_test_data): Likewise.
* math/libm-test-support.c: Likewise.
* math/libm-test-support.h: Likewise.
* sysdeps/generic/libm-test-ulps: Likewise.
Adhemerval Zanella
Joe Ramsay
Paul Eggert
Wilco Dijkstra
Joseph Myers
Alistair Francis