As discussed at the patch review meeting
Signed-off-by: Andreas K. Hüttel <dilfridge@gentoo.org>
Reviewed-by: Simon Chopin <simon.chopin@canonical.com>
Bump autoconf requirement to 2.71 to allow regenerating configure on
more recent distributions. autoconf 2.71 has been in Fedora since F36
and is the current version in Debian stable (bookworm). It appears to
be current in Gentoo as well.
All sysdeps configure and preconfigure scripts have also been
regenerated; all changes are trivial transformations that do not affect
functionality.
Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Some of the s390-specific configure checks are using compile and
link configure tests. Now use only compile tests as the link
tests fails when e.g. bootstrapping a cross-toolchain due to
missing crt-files/libc.so. This is achieved by using
AC_COMPILE_IFELSE in configure.ac file.
This is observable e.g. when using buildroot which builds glibc
only once or the build-many-glibcs.py script. Note that the latter
one is building glibc twice in the compilers-step (configure-checks
fails) and in the glibcs-step (configure-checks succeed).
Note, that the s390 specific configure tests for static PIE have to
link an executable to test binutils support. Thus we can't fix
those tests.
PI_STATIC_AND_HIDDEN indicates whether accesses to internal linkage
variables and hidden visibility variables in a shared object (ld.so)
need dynamic relocations (usually R_*_RELATIVE). PI (position
independent) in the macro name is a misnomer: a code sequence using GOT
is typically position-independent as well, but using dynamic relocations
does not meet the requirement.
Not defining PI_STATIC_AND_HIDDEN is legacy and we expect that all new
ports will define PI_STATIC_AND_HIDDEN. Current ports defining
PI_STATIC_AND_HIDDEN are more than the opposite. Change the configure
default.
No functional change.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This patch replaced obsolete AC_TRY_COMPILE to AC_COMPILE_IFELSE or
AC_PREPROC_IFELSE.
It has been confirmed that GNU 'autoconf' 2.69 suppressed obsolete
warnings, updated the following files:
- configure
- sysdeps/mach/configure
- sysdeps/mach/hurd/configure
- sysdeps/s390/configure
- sysdeps/unix/sysv/linux/configure
and didn't change the following files:
- sysdeps/ieee754/ldbl-opt/configure
- sysdeps/unix/sysv/linux/powerpc/configure
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The arch13 memmove variant is currently selected by the ifunc selector
if the Miscellaneous-Instruction-Extensions Facility 3 facility bit
is present, but the function is also using vector instructions.
If the vector support is not present, one is receiving an operation
exception.
Therefore this patch also checks for vector support in the ifunc
selector and in ifunc-impl-list.c.
Just to be sure, the configure check is now also testing an arch13
vector instruction and an arch13 Miscellaneous-Instruction-Extensions
Facility 3 instruction.
GCC 6.5 fails to correctly build ldconfig with recent ld.so.cache
commits, e.g.:
785969a047
elf: Implement a string table for ldconfig, with tail merging
If glibc is build with gcc 6.5.0:
__builtin_add_overflow is used in
<glibc>/elf/stringtable.c:stringtable_finalize()
which leads to ldconfig failing with "String table is too large".
This is also recognizable in following tests:
FAIL: elf/tst-glibc-hwcaps-cache
FAIL: elf/tst-glibc-hwcaps-prepend-cache
FAIL: elf/tst-ldconfig-X
FAIL: elf/tst-ldconfig-bad-aux-cache
FAIL: elf/tst-ldconfig-ld_so_conf-update
FAIL: elf/tst-stringtable
See gcc "Bug 98269 - gcc 6.5.0 __builtin_add_overflow() with small
uint32_t values incorrectly detects overflow"
(https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98269)
Add two configure checks which detect if arch13 is supported
by the assembler at all - by explicitely setting the machine -
and if it is supported with default settings.
ChangeLog:
* config.h.in (HAVE_S390_MIN_ARCH13_ZARCH_ASM_SUPPORT,
HAVE_S390_ARCH13_ASM_SUPPORT): New undefine.
* sysdeps/s390/configure.ac: Add checks for arch13 support.
* sysdeps/s390/configure: Regenerated.
Add a configure check for z13 in the same way as done for z196.
ChangeLog:
* config.h.in (HAVE_S390_MIN_Z13_ZARCH_ASM_SUPPORT): New undefine.
* sysdeps/s390/configure.ac: Add check for z13 support.
* sysdeps/s390/configure: Regenerated.
Add a configure check for z10 in the same way as done for z196.
ChangeLog:
* config.h.in (HAVE_S390_MIN_Z10_ZARCH_ASM_SUPPORT): New undefine.
* sysdeps/s390/configure.ac: Add check for z10 support.
* sysdeps/s390/configure: Regenerated.
This patch adds several new tunables to control the behavior of
elision on supported platforms[1]. Since elision now depends
on tunables, we should always *compile* with elision enabled,
and leave the code disabled, but available for runtime
selection. This gives us *much* better compile-time testing of
the existing code to avoid bit-rot[2].
Tested on ppc, ppc64, ppc64le, s390x and x86_64.
[1] This part of the patch was initially proposed by
Paul Murphy but was "staled" because the framework have changed
since the patch was originally proposed:
https://patchwork.sourceware.org/patch/10342/
[2] This part of the patch was inititally proposed as a RFC by
Carlos O'Donnell. Make sense to me integrate this on the patch:
https://sourceware.org/ml/libc-alpha/2017-05/msg00335.html
* elf/dl-tunables.list: Add elision parameters.
* manual/tunables.texi: Add entries about elision tunable.
* sysdeps/unix/sysv/linux/powerpc/elision-conf.c:
Add callback functions to dynamically enable/disable elision.
Add multiple callbacks functions to set elision parameters.
Deleted __libc_enable_secure check.
* sysdeps/unix/sysv/linux/s390/elision-conf.c: Likewise.
* sysdeps/unix/sysv/linux/x86/elision-conf.c: Likewise.
* configure: Regenerated.
* configure.ac: Option enable_lock_elision was deleted.
* config.h.in: ENABLE_LOCK_ELISION flag was deleted.
* config.make.in: Remove references to enable_lock_elision.
* manual/install.texi: Elision configure option was removed.
* INSTALL: Regenerated to remove enable_lock_elision.
* nptl/Makefile:
Disable elision so it can verify error case for destroying a mutex.
* sysdeps/powerpc/nptl/elide.h:
Cleanup ENABLE_LOCK_ELISION check.
Deleted macros for the case when ENABLE_LOCK_ELISION was not defined.
* sysdeps/s390/configure: Regenerated.
* sysdeps/s390/configure.ac: Remove references to enable_lock_elision..
* nptl/tst-mutex8.c:
Deleted all #ifndef ENABLE_LOCK_ELISION from the test.
* sysdeps/powerpc/powerpc32/sysdep.h:
Deleted all ENABLE_LOCK_ELISION checks.
* sysdeps/powerpc/powerpc64/sysdep.h: Likewise.
* sysdeps/powerpc/sysdep.h: Likewise.
* sysdeps/s390/nptl/bits/pthreadtypes-arch.h: Likewise.
* sysdeps/unix/sysv/linux/powerpc/force-elision.h: Likewise.
* sysdeps/unix/sysv/linux/s390/elision-conf.h: Likewise.
* sysdeps/unix/sysv/linux/s390/force-elision.h: Likewise.
* sysdeps/unix/sysv/linux/s390/lowlevellock.h: Likewise.
* sysdeps/unix/sysv/linux/s390/Makefile: Remove references to
enable-lock-elision.
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.vnet.ibm.com>
This patch implements a requirement of binutils >= 2.25 (up from 2.22)
to build glibc. Tests for 2.24 or later on x86_64 and s390 are
removed. It was already the case, as indicated by buildbot results,
that 2.24 was too old for building tests for 32-bit x86 (produced
internal linker errors linking elf/tst-gnu2-tls1mod.so). I don't know
if any configure tests for binutils features are obsolete given the
increased version requirement.
Tested for x86_64.
* configure.ac (AS): Require binutils 2.25 or later.
(LD): Likewise.
* configure: Regenerated.
* sysdeps/s390/configure.ac (AS): Remove version check.
* sysdeps/s390/configure: Regenerated.
* sysdeps/x86_64/configure.ac (AS): Remove version check.
* sysdeps/x86_64/configure: Regenerated.
* manual/install.texi (Tools for Compilation): Document
requirement for binutils 2.25 or later.
* INSTALL: Regenerated.
On s390 feraiseexcept (FE_OVERFLOW|FE_UNDERFLOW) sets FE_INEXACT, too.
This patch uses z196 zarch load rounded instruction which can suppress
FE_INEXACT exception if gcc has z196 support in used configuration.
Otherwise FE_INEXACT flag is set as before. The gcc support is tested
in a new configure-check.
A comment in fsetexcptflg.c is corrected as new exceptions are not
executed with the next floating-point instruction if fpc is set with
_FPU_SETCW macro. It seems the comment was copied e.g. from
sysdeps/x86_64/fpu/fsetexcptflg.c file.
ChangeLog:
* config.h.in (HAVE_S390_MIN_Z196_ZARCH_ASM_SUPPORT):
New undefine.
* sysdeps/s390/configure.ac: Add test for z196 zarch support.
* sysdeps/s390/configure: Regenerated.
* sysdeps/s390/fpu/fraiseexcpt.c (__feraiseexcept): Use ledbra
instruction for raising over-/underflow if z196 zarch is supported
by default.
* sysdeps/s390/fpu/fsetexcptflg.c (fesetexceptflag):
Correct comment.
The S390 specific test checks if the gcc has support for vector registers
by compiling an inline assembly which clobbers vector registers.
On success the macro HAVE_S390_VX_GCC_SUPPORT is defined.
This macro can be used to determine if e.g. clobbering vector registers
is allowed or not.
ChangeLog:
* config.h.in (HAVE_S390_VX_GCC_SUPPORT): New macro undefine.
* sysdeps/s390/configure.ac: Add test for S390 vector register
support in gcc.
* sysdeps/s390/configure: Regenerated.
The S390 specific test checks if the assembler has support for the new z13
vector instructions by compiling a vector instruction. The .machine and
.machinemode directives are needed to compile the vector instruction without
-march=z13 option on 31/64 bit.
On success the macro HAVE_S390_VX_ASM_SUPPORT is defined. This macro is used
to determine if the optimized functions can be build without compile errors.
If the used assembler lacks vector support, then a warning is dumped while
configuring and only the common code functions are build.
The z13 instruction support was introduced in
"[Committed] S/390: Add support for IBM z13."
(https://sourceware.org/ml/binutils/2015-01/msg00197.html)
ChangeLog:
* config.h.in (HAVE_S390_VX_ASM_SUPPORT): New macro undefine.
* sysdeps/s390/configure.ac: Add test for S390 vector instruction
assembler support.
* sysdeps/s390/configure: Regenerated.
Added support for TX lock elision of pthread mutexes on s390 and
s390x. This may improve lock scaling of existing programs on TX
capable systems. The lock elision code is only built with
--enable-lock-elision=yes and then requires a GCC version supporting
the TX builtins. With lock elision default mutexes are elided via
__builtin_tbegin, if the cpu supports transactions. By default lock
elision is not enabled and the elision code is not built.
