This version uses VSX store vector with length instructions and is
significantly faster on small strings and relatively unaligned large
strings, compared to the POWER8 version. A few examples:
__strcpy_power9 __strcpy_power8
Length 16, alignments in bytes 0/ 0: 2.52454 4.62695
Length 412, alignments in bytes 4/ 0: 11.6 22.9185
strcmp is used while resolving PLT references. Vector registers
should not be used during this. The P9 strcmp makes heavy use of
vector registers, so it should be avoided in rtld.
This prevents quiet vector register corruption when glibc is configured
with --disable-multi-arch and --with-cpu=power9. This can be seen with
test-float64x-compat_totalordermag during the first call into
totalordermagf64x@GLIBC_2.27.
Add a guard to fallback to the power8 implementation when building
power9 strcmp for libraries other than libc.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
On platforms where long double may have two different formats, i.e.: the
same format as double (64-bits) or something else (128-bits), building
with -mlong-double-128 is the default and function calls in the user
program match the name of the function in Glibc. When building with
-mlong-double-64, Glibc installed headers redirect such calls to the
appropriate function.
Likewise, the internals of glibc are now built against IEEE long double.
However, the only (minimally) notable usage of long double is difftime.
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
GCC 7.5.0 (PR94200) will refuse to compile if both -mabi=% and
-mlong-double-128 are passed on the command line. Surprisingly,
it will work happily if the latter is not. For the sake of
maintaining status quo, test for and blacklist such compilers.
Tested with a GCC 8.3.1 and GCC 7.5.0 compiler for ppc64le.
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
This is a small step up from 2.25 which brings in support for
rewriting the .gnu.attributes section of libc/libm.so.
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
Add compiler feature tests to ensure we can build ieee128 long double.
These test for -mabi=ieeelongdouble, -mno-gnu-attribute, and -Wno-psabi.
Likewise, verify some compiler bugs have been addressed. These aren't
helpful for building glibc, but may cause test failures when testing
the new long double. See notes below from Raji.
On powerpc64le, some older compiler versions give error for the function
signbit() for 128-bit floating point types. This is fixed by PR83862
in gcc 8.0 and backported to gcc6 and gcc7. This patch adds a test
to check compiler version to avoid compiler errors during make check.
Likewise, test for -mno-gnu-attribute support which was
On powerpc64le, a few files are built on IEEE long double mode
(-mabi=ieeelongdouble), whereas most are built on IBM long double mode
(-mabi=ibmlongdouble, the default for -mlong-double-128). Since binutils
2.31, linking object files with different long double modes causes
errors similar to:
ld: libc_pic.a(s_isinfl.os) uses IBM long double,
libc_pic.a(ieee128-qefgcvt.os) uses IEEE long double.
collect2: error: ld returned 1 exit status
make[2]: *** [../Makerules:649: libc_pic.os] Error 1
The warnings are fair and correct, but in order for glibc to have
support for both long double modes on powerpc64le, they have to be
ignored. This can be accomplished with the use of -mno-gnu-attribute
option when building the few files that require IEEE long double mode.
However, -mno-gnu-attribute is not available in GCC 6, the minimum
version required to build glibc, so this patch adds a test for this
feature in powerpc64le builds, and fails early if it's not available.
Co-Authored-By: Rajalakshmi Srinivasaraghavan <raji@linux.vnet.ibm.com>
Co-Authored-By: Gabriel F. T. Gomes <gabrielftg@linux.ibm.com>
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
We turn off this feature to avoid polluting our shared libary with
a specific value. However, static libgcc is not under our control,
and has enabled this for ibm128 routines. This pollutes the
resulting shared libraries with it.
Attach a post-linking hook to replace this section with one crafted
as hard-float + indeterminate ldbl. This allows IEEE ldbl users to
avoid having to disable the gnu attributes feature which should
protect them from linking ibm ldbl libraries using the gnu attributes
feature.
Currently, this only replaces libc and libm which support both ldbl
formats and rely on application code to explicitly determine which
is to be used.
Strictly speaking, the section could be deleted with minimal lost value.
However correctly set attributes could prove useful for some future change,
and similarly missing attributes.
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
-mabi=ieeelongdouble triggers the stdc++ libraries _Float128
support, which then breaks if algorithm is included. For now,
explicitly disable _Float128 for such tests.
I have opened up GCC BZ 94080 to track this.
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
I have observed a bug on 7.4.0 whereby __mulkc3 calls are
swapped with __multc3 depending on ABI selection. For the
sake of being overly cautious, build all _Float128 files
with ibm128 to workaround these compilers. This has been
noted in GCC BZ 84914, and will not be fixed for GCC 7.
Likewise, non-math files built with _Float128 are assumed
to have ibm long double. Explicilty preserve this
assumption.
Finally, add some bootstrapping code to avoid applying
these options until IEEE long double is enabled as they
require GCC 7 and above.
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
Adds a POWER9 version of fmaf128 that uses the xsmaddqp
instruction.
Co-authored-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Some of these files depend on the avoidance of using the various
register sets of POWER. When enabling the IEEE 128 long double,
we must be sure to disable this ABI as some compilers will
refuse to compile if -mno-vsx and -mabi=ieeelongdouble are both
present.
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
In practice, this flag should be applied globally, but it makes a good
sanity check to ensure ibm128 and ieee128 long double files are not
getting mismatched. _Float128 files use no long double, thus are
always safe to use this option.
Similarly, when investigating the linker complaints, difftime
makes trivial, self contained, usage of long double, so thus it
is also explicitly marked as such.
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
This better resembles the default linking process with the gnulibs,
and also resolves the increasingly difficult to maintain
f128-loader-link usage on powerpc64le as some libgcc symbols are
dependent on those found in the loader (ld).
Ensure the correct ldouble abi flags are applied to ibm128 files and
nldbl files. Remove the IEEE options if used, and apply the flags
used to build ldouble files which are ibm128 abi.
nldbl tests are a little tricky. To use the support, we must remove
all ldouble abi flags, and ensure -mlong-double-64 is used.
Co-authored-by: Rajalakshmi Srinivasaraghavan <raji@linux.vnet.ibm.com>
Co-authored-by: Tulio Magno Quites Machado Filho <tuliom@linux.vnet.ibm.com>
Co-authored-by: Paul E. Murphy <murphyp@linux.vnet.ibm.com>
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.
This patch adds a new macro, libm_alias_finite, to define all _finite
symbol. It sets all _finite symbol as compat symbol based on its first
version (obtained from the definition at built generated first-versions.h).
The <fn>f128_finite symbols were introduced in GLIBC 2.26 and so need
special treatment in code that is shared between long double and float128.
It is done by adding a list, similar to internal symbol redifinition,
on sysdeps/ieee754/float128/float128_private.h.
Alpha also needs some tricky changes to ensure we still emit 2 compat
symbols for sqrt(f).
Passes buildmanyglibc.
Co-authored-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Since commit a3cc4f48e9 ("Remove
--as-needed configure test."), --as-needed support is no longer
optional.
The macros are not much shorter and do not provide documentary
value, either, so this commit removes them.
Replace inline asm uses of the "mffs" and "mtfsf" instructions with
the analogous GCC builtins.
__builtin_mffs and __builtin_mtfsf are both available in GCC 5 and above.
Given the minimum GCC level for GLibC is now GCC 6.2, it is safe to use
these builtins without restriction.
2019-03-29 Paul A. Clarke <pc@us.ibm.com>
* sysdeps/powerpc/fpu/fenv_libc.h (fegetenv_register): Replace inline
asm with builtin.
* sysdeps/powerpc/powerpc64/le/fpu/sfp-machine.h (FP_INIT_ROUNDMODE):
Likewise.
* sysdeps/powerpc/fpu/tst-setcontext-fpscr.c (_GET_DI_FPSCR): Likewise.
(_GET_SI_FPSCR): Likewise.
(_SET_SI_FPSCR): Likewise.
This patch fixes more places where a space should have been present
before '(' in accordance with the GNU Coding Standards (as with the
previous patch, mainly for calls to sizeof).
Tested with build-many-glibcs.py.
* sysdeps/powerpc/powerpc32/dl-machine.c
(__elf_machine_fixup_plt): Use space before '('.
(__process_machine_rela): Likewise.
* sysdeps/powerpc/powerpc32/register-dump.h (register_dump):
Likewise.
* sysdeps/powerpc/powerpc64/le/fpu/sfp-machine.h (TI_BITS):
Likewise.
* sysdeps/powerpc/powerpc64/register-dump.h (register_dump):
Likewise.
* sysdeps/powerpc/test-arith.c (union_t): Likewise.
(pattern): Likewise.
(delta): Likewise.
(check_result): Likewise.
(check_excepts): Likewise.
(check_op): Likewise.
(fail_xr): Likewise.
* sysdeps/unix/alpha/sysdep.h (syscall_promote): Likewise.
* sysdeps/unix/sysv/linux/alpha/a.out.h (AOUTHSZ): Likewise.
(SCNHSZ): Likewise.
* sysdeps/unix/sysv/linux/hppa/makecontext.c (FRAME_SIZE_BYTES):
Likewise.
(ARGS): Likewise.
(__makecontext): Likewise.
* sysdeps/unix/sysv/linux/powerpc/sys/ucontext.h (ucontext_t):
Likewise.
The configure fragment for powerpc64le contains a test for the presence
of several compiler builtins and of the __float128 type, which are
provided by GCC 6.2 for powerpc64le. Since this configure test was
added, the compiler version required to build glibc for powerpc64le was
different than that required for the other architectures.
Now that glibc requires GCC 6.2 globally (since commit ID 4dcbbc3b28),
this patch removes the powerpc64le-specific test.
Even tough the configure test checks for compiler features rather than
compiler version, the intent of the test was to stop build attempts at
early stages, if they had been configured with a too old compiler. It
was not the intention of the test to detect compiler breakage (such as
the removal of the required compiler features in future GCC versions),
and glibc is not the place to test for compiler regressions, anyway.
Tested for powerpc64le with GCC 6.2 (built with build-many-glibcs.py).
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
This patch moves little endian specific POWER9 optimization files to
sysdeps/powerpc/powerpc64/le and creates POWER9 ifunc functions
only for little endian.
My recent nan-sign tests fail to build for powerpc64le with GCC 8
because of the special compile / link options needed there for any
test using _Float128. This patch arranges for these tests to be
handled on powerpc64le similarly to other such tests.
Tested with build-many-glibcs.py for powerpc64le.
[BZ #23303]
* sysdeps/powerpc/powerpc64/le/Makefile
(CFLAGS-tst-strtod-nan-sign.c): Add -mfloat128.
(CFLAGS-tst-wcstod-nan-sign.c): Likewise.
(gnulib-tests): Also add $(f128-loader-link) for
tst-strtod-nan-sign abd tst-wcstod-nan-sign.
When building with -mlong-double-128 or -mabi=ibmlongdouble, TFtype
represents the IBM 128-bit extended floating point type, while KFtype
represents the IEEE 128-bit floating point type.
The soft float implementation of e_sqrtf128 had to redefine TFtype and
TF in order to workaround this issue. However, this behavior changes
when -mabi=ieeelongdouble is used and the macros are not necessary.
* sysdeps/powerpc/powerpc64/le/fpu/e_sqrtf128.c
[__HAVE_FLOAT128_UNLIKE_LDBL] (TFtype, TF): Restrict TFtype
and TF redirection to KFtype and KF only when the default
long double type is not the IEEE 128-bit floating point type.
Signed-off-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
This patch creates ifunc for sqrtf128() to make use of new xssqrtqp
instruction for POWER9 when --enable-multi-arch and --with-cpu=power8
options are used on power9 system. This is achieved by explicitly
adding -mcpu=power9 flag for sqrtf128-power9.
Currently, powerpc, powerpc64, and powerpc64le imply the same set of
subdirectories from sysdeps/ieee754: flt-32, dbl-64, ldbl-128ibm, and
ldbl-opt. In preparation for the transition of the long double format -
from IBM Extended Precision to IEEE 754 128-bits floating-point - on
powerpc64le, this patch splits the shared Implies file into three
separate files (one for each of the powerpc architectures), without
changing their contents. Future patches will modify powerpc64le.
* sysdeps/powerpc/Implies: Removed. Previous contents copied to...
* sysdeps/powerpc/powerpc32/Implies-after: ... here.
* sysdeps/powerpc/powerpc64/be/Implies-after: ... here.
* sysdeps/powerpc/powerpc64/le/Implies-before: ... and here.
The creation of the divergent sysdeps directory for powerpc64le
commit 2f7f3cd8cd
Author: Paul E. Murphy <murphyp@linux.vnet.ibm.com>
Date: Fri Jul 15 18:04:40 2016 -0500
powerpc64le: Create divergent sysdep directory for powerpc64le.
allowed float128 to be enabled for powerpc64le (little-endian) and not
for powerpc64 (big-endian). Since the only intended difference between
them was the presence or absence of the float128 interface, the sysdeps
directory for powerpc64le explicitly reused the files from powerpc64
(through the use of Implies files).
Although this works, it also means that files under the powerpc64
directory might be preferred over files under powerpc64le. For
instance, on a build for powerpc64le with target set to power9, a file
from powerpc64/power5 might get built, even though a file with the same
name exists in powerpc64le/power8. That happens because the processor
hierarchy was only defined in the sysdeps directory for powerpc64 (and
borrowed by powerpc64le).
This patch fixes this behavior, by creating new subdirectories under
powerpc64 (i.e.: powerpc64/be and powerpc64/le) and creating new Implies
files to provide the hierarchy of processors for powerpc64 and
powerpc64le separately. These changes have no effect on installed,
stripped binaries (which remain unchanged).
Tested that installed stripped binaries are unchanged and that there are
no regressions on powerpc64 and powerpc64le.
