Converting double precision constants to float is now affected by the
runtime dynamic rounding mode instead of being evaluated at compile
time with default rounding mode (except static object initializers).
This can change the computed result and cause performance regression.
The known correctness issues (increased ulp errors) are already fixed,
this patch fixes remaining cases of unnecessary runtime conversions.
Add float M_* macros to math.h as new GNU extension API. To avoid
conversions the new M_* macros are used and instead of casting double
literals to float, use float literals (only required if the conversion
is inexact).
The patch was tested on aarch64 where the following symbols had new
spurious conversion instructions that got fixed:
__clog10f
__gammaf_r_finite@GLIBC_2.17
__j0f_finite@GLIBC_2.17
__j1f_finite@GLIBC_2.17
__jnf_finite@GLIBC_2.17
__kernel_casinhf
__lgamma_negf
__log1pf
__y0f_finite@GLIBC_2.17
__y1f_finite@GLIBC_2.17
cacosf
cacoshf
casinhf
catanf
catanhf
clogf
gammaf_positive
Fixes bug 28713.
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
We stopped adding "Contributed by" or similar lines in sources in 2012
in favour of git logs and keeping the Contributors section of the
glibc manual up to date. Removing these lines makes the license
header a bit more consistent across files and also removes the
possibility of error in attribution when license blocks or files are
copied across since the contributed-by lines don't actually reflect
reality in those cases.
Move all "Contributed by" and similar lines (Written by, Test by,
etc.) into a new file CONTRIBUTED-BY to retain record of these
contributions. These contributors are also mentioned in
manual/contrib.texi, so we just maintain this additional record as a
courtesy to the earlier developers.
The following scripts were used to filter a list of files to edit in
place and to clean up the CONTRIBUTED-BY file respectively. These
were not added to the glibc sources because they're not expected to be
of any use in future given that this is a one time task:
https://gist.github.com/siddhesh/b5ecac94eabfd72ed2916d6d8157e7dchttps://gist.github.com/siddhesh/15ea1f5e435ace9774f485030695ee02
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
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
Continuing the process of setting up common macros for libm function
aliases, with a view to using them to define _FloatN / _FloatNx
aliases in future, this patch adds a libm_alias_double macro and uses
it in the type-generic templates.
This macro handles defining aliases for double, and for long double in
the NO_LONG_DOUBLE case. It also handles defining compat symbols for
long double = double for architectures that changed their long double
format. By so doing, it eliminates the need for the
M_LIBM_NEED_COMPAT and declare_mgen_libm_compat macros; the single
declare_mgen_alias call in each template now suffices to define all
required compat symbols. When used for more double functions (not
based on type-generic templates), I expect it will eliminate the need
for most ldbl-opt wrappers for such functions.
A few special cases are needed. __clog10l is a public symbol (for
historical reasons) so needs to be given appropriate compat versions
for architectures that changed their long double format, but is not
defined as an alias using the normal macros since __clog10* are *not*
public symbols for _FloatN / _FloatNx types. For scalbn, scalbln and
log1p, the changes adding errno setting support for those functions
left compat symbols pointing directly to the non-errno-setting
implementations. There is no requirement for the compat symbols not
to set errno; that just made for the simplest patches at that time.
Now, with these common macros, it's natural to redirect the compat
symbols to the errno-setting wrappers, which I intend to do in a
separate patch.
Tested for x86_64, and with build-many-glibcs.py. For ldbl-opt
platforms the stripped libm.so binaries are changed (disassembly
unchanged) because the details of how the clog10l compat symbol is
created mean it ceases to be weak as it was before; for other
platforms, stripped libm.so binaries are unchanged.
2017-09-13 Joseph Myers <joseph@codesourcery.com>
* sysdeps/generic/libm-alias-double.h: New file.
* sysdeps/ieee754/ldbl-opt/libm-alias-double.h: Likewise.
* sysdeps/generic/math-type-macros-double.h: Include
<libm-alias-double.h>.
[declare_mgen_alias] (declare_mgen_alias): Define to use
libm_alias_double.
* sysdeps/generic/math-type-macros.h [!M_LIBM_NEED_COMPAT]
(M_LIBM_NEED_COMPAT): Remove macro.
[!M_LIBM_NEED_COMPAT] (declare_mgen_libm_compat): Likewise.
* sysdeps/ieee754/ldbl-opt/math-type-macros-double.h: Remove.
* math/cabs_template.c [M_LIBM_NEED_COMPAT]: Remove conditional
code.
* math/carg_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/cimag_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/conj_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/creal_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_cacos_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_cacosh_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_casin_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_casinh_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_catan_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_catanh_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_ccos_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_ccosh_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_cexp_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_clog10_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_clog_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_cpow_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_cproj_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_csin_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_csinh_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_csqrt_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_ctan_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_ctanh_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_fdim_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_fmax_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_fmin_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/s_nan_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* math/w_ilogb_template.c [M_LIBM_NEED_COMPAT]: Likewise.
* sysdeps/ieee754/ldbl-opt/s_clog10.c: New file.
* sysdeps/ieee754/ldbl-opt/s_ldexp.c (M_LIBM_NEED_COMPAT): Remove
macro.
(declare_mgen_alias): New macro.
* sysdeps/ieee754/ldbl-opt/w_log1p.c: New file.
* sysdeps/ieee754/ldbl-opt/w_scalbln.c: Likewise.
* sysdeps/sparc/sparc32/sparcv9/fpu/multiarch/s_fdim-vis3.c
(M_LIBM_NEED_COMPAT): Remove macro.
* sysdeps/sparc/sparc32/sparcv9/fpu/multiarch/s_fdim.c
[HAVE_AS_VIS3_SUPPORT]: Include <math_ldbl_opt.h> and
<first-versions.h>.
[HAVE_AS_VIS3_SUPPORT && LONG_DOUBLE_COMPAT (libm,
FIRST_VERSION_libm_fdiml)]: Define fdiml as compat symbol.
This patch has no function changes, except to
ensure the git history correctly tracks the
changes to convert the double version of these
functions into a templated version.
