Remove generic tlsdesc code related to lazy tlsdesc processing since
lazy tlsdesc relocation is no longer supported. This includes removing
GL(dl_load_lock) from _dl_make_tlsdesc_dynamic which is only called at
load time when that lock is already held.
Added a documentation comment too.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Lazy tlsdesc relocation is racy because the static tls optimization and
tlsdesc management operations are done without holding the dlopen lock.
This similar to the commit b7cf203b5c
for aarch64, but it fixes a different race: bug 27137.
On i386 the code is a bit more complicated than on x86_64 because both
rel and rela relocs are supported.
This will be used to consolidate the libgcc_s access for backtrace
and pthread_cancel.
Unlike the existing backtrace implementations, it provides some
hardening based on pointer mangling.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
It turns out the startup code in csu/elf-init.c has a perfect pair of
ROP gadgets (see Marco-Gisbert and Ripoll-Ripoll, "return-to-csu: A
New Method to Bypass 64-bit Linux ASLR"). These functions are not
needed in dynamically-linked binaries because DT_INIT/DT_INIT_ARRAY
are already processed by the dynamic linker. However, the dynamic
linker skipped the main program for some reason. For maximum
backwards compatibility, this is not changed, and instead, the main
map is consulted from __libc_start_main if the init function argument
is a NULL pointer.
For statically linked binaries, the old approach based on linker
symbols is still used because there is nothing else available.
A new symbol version __libc_start_main@@GLIBC_2.34 is introduced because
new binaries running on an old libc would not run their ELF
constructors, leading to difficult-to-debug issues.
Add SUPPORT_STATIC_PIE that targets can define if they support
static PIE. This requires PI_STATIC_AND_HIDDEN support and various
linker features as described in
commit 9d7a3741c9
Add --enable-static-pie configure option to build static PIE [BZ #19574]
Currently defined on x86_64, i386 and aarch64 where static PIE is
known to work.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Calling an IFUNC function defined in unrelocated executable also leads to
segfault. Issue a fatal error message when calling IFUNC function defined
in the unrelocated executable from a shared library.
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
This syncs up isnanl behaviour with gcc. Also move the isnanl
implementation to sysdeps/x86 and remove the sysdeps/x86_64 version.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Also move sysdeps/i386/fpu/s_fpclassifyl.c to
sysdeps/x86/fpu/s_fpclassifyl.c and remove
sysdeps/x86_64/fpu/s_fpclassifyl.c
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The previous definition of THREAD_SELF did not tell the compiler
that %fs (or %gs) usage is invalid for the !DL_LOOKUP_GSCOPE_LOCK
case in _dl_lookup_symbol_x. As a result, ld.so could try to use the
TCB before it was initialized.
As the comment in tls.h explains, asm volatile is undesirable here.
Using the __seg_fs (or __seg_gs) namespace does not interfere with
optimization, and expresses that THREAD_SELF is potentially trapping.
Now __thread_gscope_wait (the function behind THREAD_GSCOPE_WAIT,
formerly __wait_lookup_done) can be implemented directly in ld.so,
eliminating the unprotected GL (dl_wait_lookup_done) function
pointer.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The UP macro is never defined. Also define LOCK_PREFIX
unconditionally, to the same string.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
We need NO_RTLD_HIDDEN because of the need for PLT calls in ld.so.
See Roland's comment in
https://sourceware.org/bugzilla/show_bug.cgi?id=15605
"in the Hurd it's crucial that calls like __mmap be the libc ones
instead of the rtld-local ones after the bootstrap phase, when the
dynamic linker is being used for dlopen and the like."
We used to just avoid all hidden use in the rtld ; this commit switches to
keeping only those that should use PLT calls, i.e. essentially those defined in
sysdeps/mach/hurd/dl-sysdep.c:
__assert_fail
__assert_perror_fail
__*stat64
_exit
This fixes a few startup issues, notably the call to __tunable_get_val that is
made before PLTs are set up.
X86 CPU features in ld.so are initialized by init_cpu_features, which is
invoked by DL_PLATFORM_INIT from _dl_sysdep_start. But when ld.so is
loaded by static executable, DL_PLATFORM_INIT is never called. Also
x86 cache info in libc.o and libc.a is initialized by a constructor
which may be called too late. Since some fields in _rtld_global_ro
in ld.so are initialized by dynamic relocation, we can also initialize
x86 CPU features in _rtld_global_ro in ld.so and cache info in libc.so
by initializing dummy function pointers in ld.so and libc.so via IFUNC
relocation.
Key points:
1. IFUNC is always supported, independent of --enable-multi-arch or
--disable-multi-arch. Linker generates IFUNC relocations from input
IFUNC objects and ld.so performs IFUNC relocations.
2. There are no IFUNC dependencies in ld.so before dynamic relocation
have been performed,
3. The x86 CPU features in ld.so is initialized by DL_PLATFORM_INIT
in dynamic executable and by IFUNC relocation in dlopen in static
executable.
4. The x86 cache info in libc.o is initialized by IFUNC relocation.
5. In libc.a, both x86 CPU features and cache info are initialized from
ARCH_INIT_CPU_FEATURES, not by IFUNC relocation, before __libc_early_init
is called.
Note: _dl_x86_init_cpu_features can be called more than once from
DL_PLATFORM_INIT and during relocation in ld.so.
There are several compiler implementations that allow large stack
allocations to jump over the guard page at the end of the stack and
corrupt memory beyond that. See CVE-2017-1000364.
Compilers can emit code to probe the stack such that the guard page
cannot be skipped, but on aarch64 the probe interval is 64K by default
instead of the minimum supported page size (4K).
This patch enforces at least 64K guard on aarch64 unless the guard
is disabled by setting its size to 0. For backward compatibility
reasons the increased guard is not reported, so it is only observable
by exhausting the address space or parsing /proc/self/maps on linux.
On other targets the patch has no effect. If the stack probe interval
is larger than a page size on a target then ARCH_MIN_GUARD_SIZE can
be defined to get large enough stack guard on libc allocated stacks.
The patch does not affect threads with user allocated stacks.
Fixes bug 26691.
Install <sys/platform/x86.h> so that programmers can do
#if __has_include(<sys/platform/x86.h>)
#include <sys/platform/x86.h>
#endif
...
if (CPU_FEATURE_USABLE (SSE2))
...
if (CPU_FEATURE_USABLE (AVX2))
...
<sys/platform/x86.h> exports only:
enum
{
COMMON_CPUID_INDEX_1 = 0,
COMMON_CPUID_INDEX_7,
COMMON_CPUID_INDEX_80000001,
COMMON_CPUID_INDEX_D_ECX_1,
COMMON_CPUID_INDEX_80000007,
COMMON_CPUID_INDEX_80000008,
COMMON_CPUID_INDEX_7_ECX_1,
/* Keep the following line at the end. */
COMMON_CPUID_INDEX_MAX
};
struct cpuid_features
{
struct cpuid_registers cpuid;
struct cpuid_registers usable;
};
struct cpu_features
{
struct cpu_features_basic basic;
struct cpuid_features features[COMMON_CPUID_INDEX_MAX];
};
/* Get a pointer to the CPU features structure. */
extern const struct cpu_features *__x86_get_cpu_features
(unsigned int max) __attribute__ ((const));
Since all feature checks are done through macros, programs compiled with
a newer <sys/platform/x86.h> are compatible with the older glibc binaries
as long as the layout of struct cpu_features is identical. The features
array can be expanded with backward binary compatibility for both .o and
.so files. When COMMON_CPUID_INDEX_MAX is increased to support new
processor features, __x86_get_cpu_features in the older glibc binaries
returns NULL and HAS_CPU_FEATURE/CPU_FEATURE_USABLE return false on the
new processor feature. No new symbol version is neeeded.
Both CPU_FEATURE_USABLE and HAS_CPU_FEATURE are provided. HAS_CPU_FEATURE
can be used to identify processor features.
Note: Although GCC has __builtin_cpu_supports, it only supports a subset
of <sys/platform/x86.h> and it is equivalent to CPU_FEATURE_USABLE. It
doesn't support HAS_CPU_FEATURE.
Without this ULP patch these 3 tests fail on i686:
FAIL: math/test-float128-j0
FAIL: math/test-float64x-j0
FAIL: math/test-ldouble-j0
CPU info:
Vendor ID: GenuineIntel
CPU family: 6
Model: 85
Model name: Intel Xeon Processor (Cascadelake)
Support usable check for all CPU features with the following changes:
1. Change struct cpu_features to
struct cpuid_features
{
struct cpuid_registers cpuid;
struct cpuid_registers usable;
};
struct cpu_features
{
struct cpu_features_basic basic;
struct cpuid_features features[COMMON_CPUID_INDEX_MAX];
unsigned int preferred[PREFERRED_FEATURE_INDEX_MAX];
...
};
so that there is a usable bit for each cpuid bit.
2. After the cpuid bits have been initialized, copy the known bits to the
usable bits. EAX/EBX from INDEX_1 and EAX from INDEX_7 aren't used for
CPU feature detection.
3. Clear the usable bits which require OS support.
4. If the feature is supported by OS, copy its cpuid bit to its usable
bit.
5. Replace HAS_CPU_FEATURE and CPU_FEATURES_CPU_P with CPU_FEATURE_USABLE
and CPU_FEATURE_USABLE_P to check if a feature is usable.
6. Add DEPR_FPU_CS_DS for INDEX_7_EBX_13.
7. Unset MPX feature since it has been deprecated.
The results are
1. If the feature is known and doesn't requre OS support, its usable bit
is copied from the cpuid bit.
2. Otherwise, its usable bit is copied from the cpuid bit only if the
feature is known to supported by OS.
3. CPU_FEATURE_USABLE/CPU_FEATURE_USABLE_P are used to check if the
feature can be used.
4. HAS_CPU_FEATURE/CPU_FEATURE_CPU_P are used to check if CPU supports
the feature.
Since
commit c867597bff
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Wed Jun 8 13:57:50 2016 -0700
X86-64: Remove previous default/SSE2/AVX2 memcpy/memmove
removed the only usage of __x86_prefetchw, we can remove the unused
__x86_prefetchw.
* sysdeps/i386/htl/Makefile: New file.
* sysdeps/i386/htl/tcb-offsets.sym: New file.
* sysdeps/mach/hurd/i386/Makefile [setjmp] (gen-as-const-headers): Add
signal-defines.sym.
* sysdeps/mach/hurd/i386/____longjmp_chk.S: Include tcb-offsets.h.
(____longjmp_chk): Harmonize with i386's __longjmp. Clear SS_ONSTACK
when jumping off the alternate stack.
* sysdeps/mach/hurd/i386/__longjmp.S: New file.
1. Include <dl-procruntime.c> to get architecture specific initializer in
rtld_global.
2. Change _dl_x86_feature_1[2] to _dl_x86_feature_1.
3. Add _dl_x86_feature_control after _dl_x86_feature_1, which is a
struct of 2 bitfields for IBT and SHSTK control
This fixes [BZ #25887].
Most gmp-mparam.h headers in glibc define various macros to the same
values they would be defined to by the generic version of that header,
plus macros IEEE_DOUBLE_BIG_ENDIAN or IEEE_DOUBLE_MIXED_ENDIAN related
to the representation of double. The latter macros are in turn only
used in gmp-impl.h to define union ieee_double_extract, which is not
used in glibc. Thus all of these headers, except for the generic one
and those that define _LONG_LONG_LIMB for ILP32 configurations with
64-bit registers, are redundant, and this patch removes them.
Tested with build-many-glibcs.py that installed stripped shared
libraries are unchanged by this patch.
Since GCC 6.2 or later is required to build glibc, remove build support
for GCC older than GCC 6.
Testd with GCC 6.4 and GCC 9.3.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The corner cases included were generated using exhaustive search
for all float/binary32 values on x86_64 (comparing to MPFR for
correct rounding to nearest).
For the j0/j1/y0 functions, only cases with ulp error <= 9 were
included.
Reviewed-by: Carlos O'Donell <carlos@redhat.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.
GCC has moved from using .gnu.linkonce for i386 setup pic register with
minimum current version (as for binutils minimum binutils that support
comdat).
Trying to pinpoint when binutils has added comdat support for i686, it
seems it was around 2004 [1]. I also checking with some ancient
binutils older than 2.16 I see:
test.o: In function `__x86.get_pc_thunk.bx':
test.o(.text.__x86.get_pc_thunk.bx+0x0): multiple definition of `__x86.get_pc_thunk.bx'
/usr/lib/gcc/x86_64-linux-gnu/5/../../../i386-linux-gnu/crti.o(.gnu.linkonce.t.__x86.get_pc_thunk.bx+0x0): first defined here
Which seems that such version can not handle either comdat at all or
a mix of linkonce and comdat. For binutils 2.16.1 I am getting a
different issue trying to link a binary with and more recent
ctri.o (unrecognized relocation (0x2b) in section `.init', which is
R_386_GOT32X and old binutils won't generate it anyway).
So I think that either unlikely someone will use an older binutils than
the one used to glibc and even this scenario may fail with some issue
as the R_386_GOT32X. Also, 2.16.1 is quite old and not really supported
(glibc itself required 2.25).
Checked on i686-linux-gnu.
[1] https://gcc.gnu.org/ml/gcc/2004-05/msg00030.html
With all Linux ABIs using the expected Linux kABI to indicate
syscalls errors, the INTERNAL_SYSCALL_DECL is an empty declaration
on all ports.
This patch removes the 'err' argument on INTERNAL_SYSCALL* macro
and remove the INTERNAL_SYSCALL_DECL usage.
Checked with a build against all affected ABIs.
With all Linux ABIs using the expected Linux kABI to indicate
syscalls errors, there is no need to replicate the INLINE_SYSCALL.
The generic Linux sysdep.h includes errno.h even for !__ASSEMBLER__,
which is ok now and it allows cleanup some archaic code that assume
otherwise.
Checked with a build against all affected ABIs.
Use ENTRY and END in assembly codes so that ENDBR32 will be added at
function entries when CET is enabled.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
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>
This commit adds missing skip_ifunc checks to aarch64, arm, i386,
sparc, and x86_64. A new test case ensures that IRELATIVE IFUNC
resolvers do not run in various diagnostic modes of the dynamic
loader.
Reviewed-By: Szabolcs Nagy <szabolcs.nagy@arm.com>
This patch new build tests to check for internal fields offsets for
internal pthread_rwlock_t definition. Althoug the '__data.__flags'
field layout should be preserved due static initializators, the patch
also adds tests for the futexes that may be used in a shared memory
(although using different libc version in such scenario is not really
supported).
Checked with a build against all affected ABIs.
Change-Id: Iccc103d557de13d17e4a3f59a0cad2f4a640c148
The offsets of pthread_mutex_t __data.__nusers, __data.__spins,
__data.elision, __data.list are not required to be constant over
the releases. Only the __data.__kind is used for static
initializers.
This patch also adds an additional size check for __data.__kind.
Checked with a build against affected ABIs.
Change-Id: I7a4e48cc91b4c4ada57e9a5d1b151fb702bfaa9f
Since sysdeps/i386/dl-lookupcfg.h and sysdeps/x86_64/dl-lookupcfg.h are
identical, we can replace them with sysdeps/x86/dl-lookupcfg.h.
* sysdeps/i386/dl-lookupcfg.h: Moved to ...
* sysdeps/x86/dl-lookupcfg.h: Here.
* sysdeps/x86_64/dl-lookupcfg.h: Removed.
This patch fixes -Wimplicit-fallthrough warnings in system-specific
code that show up building glibc with -Wextra, by adding fall-through
comments, or moving existing such comments to the place required for
them to work (immediately before the case label being fallen through).
Tested with build-many-glibcs.py.
* sysdeps/i386/dl-machine.h (elf_machine_rela): Add fall-through
comments.
* sysdeps/m68k/m680x0/fpu/s_cexp_template.c (s(__cexp)): Likewise.
* sysdeps/m68k/memcopy.h (WORD_COPY_FWD): Likewise.
(WORD_COPY_BWD): Likewise.
* sysdeps/mach/hurd/ioctl.c (__ioctl): Likewise.
* sysdeps/powerpc/powerpc64/dl-machine.h (elf_machine_rela):
Likewise.
* sysdeps/s390/iso-8859-1_cp037_z900.c (TR_LOOP): Likewise.
* sysdeps/mips/dl-machine.h (elf_machine_reloc): Move fall-through
comment.
* sysdeps/mips/dl-trampoline.c (__dl_runtime_resolve): Likewise.
This fixes the same bug in fnmatch that was fixed by commit 7e2f0d2d77 for
regexp matching. As a side effect it also removes the use of an unbound
VLA.
The x86 defines optimized THREAD_ATOMIC_* macros where reference always
the current thread instead of the one indicated by input 'descr' argument.
It work as long the input is the self thread pointer, however it generates
wrong code if the semantic is to set a bit atomicialy from another thread.
This is not an issue for current GLIBC usage, however the new cancellation
code expects that some synchronization code to atomically set bits from
different threads.
If some usage indeed proves to be a hotspot we can add an extra macro
with a more descriptive name (THREAD_ATOMIC_BIT_SET_SELF for instance)
where i386 might optimize it.
Checked on i686-linux-gnu.
* sysdeps/i686/nptl/tls.h (THREAD_ATOMIC_CMPXCHG_VAL,
THREAD_ATOMIC_AND, THREAD_ATOMIC_BIT_SET): Remove macros.
Merge i386 and x86_64 atomic-machine.h to x86 atomic-machine.h.
Tested on i686 and x86_64 as well as with build-many-glibcs.py.
* sysdeps/i386/atomic-machine.h: Merged with ...
* sysdeps/x86_64/atomic-machine.h: To ...
* sysdeps/x86/atomic-machine.h: This. New file.
Introduce new pow symbol version that doesn't do SVID compatible error
handling. The standard errno and fp exception based error handling is
inline in the new code and does not have significant overhead.
The wrapper is disabled for sysdeps/ieee754/dbl-64 by using empty
w_pow.c and enabled for targets with their own pow implementation or
ifunc dispatch on __ieee754_pow by including math/w_pow.c.
The compatibility symbol version still uses the wrapper with SVID error
handling around the new code. There is no new symbol version nor
compatibility code on !LIBM_SVID_COMPAT targets (e.g. riscv).
On targets where previously powl was an alias of pow, now it points to
the compatibility symbol with the wrapper, because it still need the
SVID compatible error handling. This affects NO_LONG_DOUBLE (e.g. arm)
and LONG_DOUBLE_COMPAT (e.g. alpha) targets as well.
The __pow_finite symbol is now an alias of pow. Both __pow_finite and
pow set errno and thus not const functions.
The ia64 asm is changed so the compat and new symbol versions map to the
same address.
On x86_64 #include <math.h> was added before macro definitions that
may affect that header.
Tested with build-many-glibcs.py.
* math/Versions (GLIBC_2.29): Add pow.
* math/w_pow_compat.c (__pow_compat): Change to versioned compat
symbol.
* math/w_pow.c: New file.
* sysdeps/i386/fpu/w_pow.c: New file.
* sysdeps/ia64/fpu/e_pow.S: Add versioned symbols.
* sysdeps/ieee754/dbl-64/e_pow.c (__ieee754_pow): Rename to __pow
and add necessary aliases.
* sysdeps/ieee754/dbl-64/w_pow.c: New file.
* sysdeps/m68k/m680x0/fpu/w_pow.c: New file.
* sysdeps/mach/hurd/i386/libm.abilist: Update.
* sysdeps/unix/sysv/linux/aarch64/libm.abilist: Update.
* sysdeps/unix/sysv/linux/alpha/libm.abilist: Update.
* sysdeps/unix/sysv/linux/arm/libm.abilist: Update.
* sysdeps/unix/sysv/linux/hppa/libm.abilist: Update.
* sysdeps/unix/sysv/linux/i386/libm.abilist: Update.
* sysdeps/unix/sysv/linux/ia64/libm.abilist: Update.
* sysdeps/unix/sysv/linux/m68k/coldfire/libm.abilist: Update.
* sysdeps/unix/sysv/linux/m68k/m680x0/libm.abilist: Update.
* sysdeps/unix/sysv/linux/microblaze/libm.abilist: Update.
* sysdeps/unix/sysv/linux/mips/mips32/libm.abilist: Update.
* sysdeps/unix/sysv/linux/mips/mips64/libm.abilist: Update.
* sysdeps/unix/sysv/linux/nios2/libm.abilist: Update.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libm.abilist: Update.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libm.abilist: Update.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm-le.abilist: Update.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm.abilist: Update.
* sysdeps/unix/sysv/linux/s390/s390-32/libm.abilist: Update.
* sysdeps/unix/sysv/linux/s390/s390-64/libm.abilist: Update.
* sysdeps/unix/sysv/linux/sh/libm.abilist: Update.
* sysdeps/unix/sysv/linux/sparc/sparc32/libm.abilist: Update.
* sysdeps/unix/sysv/linux/sparc/sparc64/libm.abilist: Update.
* sysdeps/unix/sysv/linux/x86_64/64/libm.abilist: Update.
* sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Update.
* sysdeps/x86_64/fpu/multiarch/e_pow-fma.c (__ieee754_pow): Rename to
__pow.
* sysdeps/x86_64/fpu/multiarch/e_pow-fma4.c (__ieee754_pow): Likewise.
* sysdeps/x86_64/fpu/multiarch/e_pow.c (__ieee754_pow): Likewise.
* sysdeps/x86_64/fpu/multiarch/w_pow.c: New file.
Introduce new log2 symbol version that doesn't do SVID compatible error
handling. The standard errno and fp exception based error handling is
inline in the new code and does not have significant overhead.
The wrapper is disabled for sysdeps/ieee754/dbl-64 by using empty
w_log2.c and enabled for targets with their own log2 implementation by
including math/w_log2.c.
The compatibility symbol version still uses the wrapper with SVID error
handling around the new code. There is no new symbol version nor
compatibility code on !LIBM_SVID_COMPAT targets (e.g. riscv).
On targets where previously log2l was an alias of log2, now it points to
the compatibility symbol with the wrapper, because it still need the
SVID compatible error handling. This affects NO_LONG_DOUBLE (e.g. arm)
and LONG_DOUBLE_COMPAT (e.g. alpha) targets as well.
The __log2_finite symbol is now an alias of log2. Both __log2_finite
and log2 set errno and thus not const functions.
The ia64 asm is changed so the compat and new symbol versions map to the
same address.
Tested with build-many-glibcs.py.
* math/Versions (GLIBC_2.29): Add log2.
* math/w_log2_compat.c (__log2_compat): Change to versioned compat
symbol.
* math/w_log2.c: New file.
* sysdeps/i386/fpu/w_log2.c: New file.
* sysdeps/ia64/fpu/e_log2.S: Add versioned symbols.
* sysdeps/ieee754/dbl-64/e_log2.c (__ieee754_log2): Rename to __log2
and add necessary aliases.
* sysdeps/ieee754/dbl-64/w_log2.c: New file.
* sysdeps/m68k/m680x0/fpu/w_log2.c: New file.
* sysdeps/mach/hurd/i386/libm.abilist: Update.
* sysdeps/unix/sysv/linux/aarch64/libm.abilist: Update.
* sysdeps/unix/sysv/linux/alpha/libm.abilist: Update.
* sysdeps/unix/sysv/linux/arm/libm.abilist: Update.
* sysdeps/unix/sysv/linux/hppa/libm.abilist: Update.
* sysdeps/unix/sysv/linux/i386/libm.abilist: Update.
* sysdeps/unix/sysv/linux/ia64/libm.abilist: Update.
* sysdeps/unix/sysv/linux/m68k/coldfire/libm.abilist: Update.
* sysdeps/unix/sysv/linux/m68k/m680x0/libm.abilist: Update.
* sysdeps/unix/sysv/linux/microblaze/libm.abilist: Update.
* sysdeps/unix/sysv/linux/mips/mips32/libm.abilist: Update.
* sysdeps/unix/sysv/linux/mips/mips64/libm.abilist: Update.
* sysdeps/unix/sysv/linux/nios2/libm.abilist: Update.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libm.abilist: Update.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libm.abilist: Update.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm-le.abilist: Update.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm.abilist: Update.
* sysdeps/unix/sysv/linux/s390/s390-32/libm.abilist: Update.
* sysdeps/unix/sysv/linux/s390/s390-64/libm.abilist: Update.
* sysdeps/unix/sysv/linux/sh/libm.abilist: Update.
* sysdeps/unix/sysv/linux/sparc/sparc32/libm.abilist: Update.
* sysdeps/unix/sysv/linux/sparc/sparc64/libm.abilist: Update.
* sysdeps/unix/sysv/linux/x86_64/64/libm.abilist: Update.
* sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Update.
Introduce new log symbol version that doesn't do SVID compatible error
handling. The standard errno and fp exception based error handling is
inline in the new code and does not have significant overhead.
The wrapper is disabled for sysdeps/ieee754/dbl-64 by using empty
w_log.c and enabled for targets with their own log implementation by
including math/w_log.c.
The compatibility symbol version still uses the wrapper with SVID error
handling around the new code. There is no new symbol version nor
compatibility code on !LIBM_SVID_COMPAT targets (e.g. riscv).
On targets where previously logl was an alias of log, now it points to
the compatibility symbol with the wrapper, because it still need the
SVID compatible error handling. This affects NO_LONG_DOUBLE (e.g. arm)
and LONG_DOUBLE_COMPAT (e.g. alpha) targets as well.
The __log_finite symbol is now an alias of log. Both __log_finite and
log set errno and thus not const functions.
The ia64 asm is changed so the compat and new symbol versions map to the
same address.
On x86_64 #include <math.h> was added before macro definitions that may
affect that header.
Tested with build-many-glibcs.py.
* math/Versions (GLIBC_2.29): Add log.
* math/w_log_compat.c (__log_compat): Change to versioned compat
symbol.
* math/w_log.c: New file.
* sysdeps/i386/fpu/w_log.c: New file.
* sysdeps/ia64/fpu/e_log.S: Update.
* sysdeps/ieee754/dbl-64/e_log.c (__ieee754_log): Rename to __log
and add necessary aliases.
* sysdeps/ieee754/dbl-64/w_log.c: New file.
* sysdeps/m68k/m680x0/fpu/w_log.c: New file.
* sysdeps/mach/hurd/i386/libm.abilist: Update.
* sysdeps/unix/sysv/linux/aarch64/libm.abilist: Update.
* sysdeps/unix/sysv/linux/alpha/libm.abilist: Update.
* sysdeps/unix/sysv/linux/arm/libm.abilist: Update.
* sysdeps/unix/sysv/linux/hppa/libm.abilist: Update.
* sysdeps/unix/sysv/linux/i386/libm.abilist: Update.
* sysdeps/unix/sysv/linux/ia64/libm.abilist: Update.
* sysdeps/unix/sysv/linux/m68k/coldfire/libm.abilist: Update.
* sysdeps/unix/sysv/linux/m68k/m680x0/libm.abilist: Update.
* sysdeps/unix/sysv/linux/microblaze/libm.abilist: Update.
* sysdeps/unix/sysv/linux/mips/mips32/libm.abilist: Update.
* sysdeps/unix/sysv/linux/mips/mips64/libm.abilist: Update.
* sysdeps/unix/sysv/linux/nios2/libm.abilist: Update.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libm.abilist: Update.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libm.abilist: Update.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm-le.abilist: Update.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm.abilist: Update.
* sysdeps/unix/sysv/linux/s390/s390-32/libm.abilist: Update.
* sysdeps/unix/sysv/linux/s390/s390-64/libm.abilist: Update.
* sysdeps/unix/sysv/linux/sh/libm.abilist: Update.
* sysdeps/unix/sysv/linux/sparc/sparc32/libm.abilist: Update.
* sysdeps/unix/sysv/linux/sparc/sparc64/libm.abilist: Update.
* sysdeps/unix/sysv/linux/x86_64/64/libm.abilist: Update.
* sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Update.
* sysdeps/x86_64/fpu/multiarch/e_log-avx.c (__ieee754_log): Rename to
__log.
* sysdeps/x86_64/fpu/multiarch/e_log-fma.c (__ieee754_log): Likewise.
* sysdeps/x86_64/fpu/multiarch/e_log-fma4.c (__ieee754_log): Likewise.
* sysdeps/x86_64/fpu/multiarch/e_log.c (__ieee754_log): Likewise.
* sysdeps/x86_64/fpu/multiarch/w_log.c: New file.
Introduce new exp and exp2 symbol version that don't do SVID compatible
error handling. The standard errno and fp exception based error handling
is inline in the new code and does not have significant overhead.
The double precision wrappers are disabled for sysdeps/ieee754/dbl-64
by using empty w_exp.c and w_exp2.c files, the math/w_exp.c and
math/w_exp2.c files use the wrapper template and can be included by
targets that have their own exp and exp2 implementations or use ifunc
on the glibc internal __ieee754_exp symbol.
The compatibility symbol versions still use the wrapper with SVID error
handling around the new code. There is no new symbol version nor
compatibility code on !LIBM_SVID_COMPAT targets (e.g. riscv).
On targets where previously expl and exp2l were aliases of exp and exp2,
now they point to the compatibility symbols with the wrapper, because
they still need the SVID compatible error handling. This affects
NO_LONG_DOUBLE (e.g arm) and LONG_DOUBLE_COMPAT (e.g. alpha) targets
as well.
The _finite symbols are now aliases of the standard symbols (they have
no performance advantage anymore). Both the standard symbols and
_finite symbols set errno and thus not const functions.
The ia64 asm is changed so the compat and new symbol versions map to the
same address.
On x86_64 #include <math.h> was added before macro definitions that may
affect that header (the new macro name is __exp instead of __ieee754_exp
which breaks some math.h macros).
Tested with build-many-glibcs.py.
* math/Versions (GLIBC_2.29): Add exp and exp2.
* math/w_exp2_compat.c (__exp2_compat): Change to versioned compat
symbol, handle NO_LONG_DOUBLE and LONG_DOUBLE_COMPAT explicitly.
* math/w_exp_compat.c (__exp_compat): Likewise.
* math/w_exp.c: New file.
* math/w_exp2.c: New file.
* sysdeps/i386/fpu/w_exp.c: New file.
* sysdeps/i386/fpu/w_exp2.c: New file.
* sysdeps/ia64/fpu/e_exp.S: Add versioned symbols.
* sysdeps/ia64/fpu/e_exp2.S: Likewise.
* sysdeps/ieee754/dbl-64/e_exp.c (__ieee754_exp): Rename to __exp
and add necessary aliases.
* sysdeps/ieee754/dbl-64/e_exp2.c (__ieee754_exp2): Rename to __exp2
and add necessary aliases.
* sysdeps/ieee754/dbl-64/w_exp.c: New file.
* sysdeps/ieee754/dbl-64/w_exp2.c: New file.
* sysdeps/m68k/m680x0/fpu/w_exp.c: New file.
* sysdeps/m68k/m680x0/fpu/w_exp2.c: New file.
* sysdeps/mach/hurd/i386/libm.abilist: Update.
* sysdeps/unix/sysv/linux/aarch64/libm.abilist: Update.
* sysdeps/unix/sysv/linux/alpha/libm.abilist: Update.
* sysdeps/unix/sysv/linux/arm/libm.abilist: Update.
* sysdeps/unix/sysv/linux/hppa/libm.abilist: Update.
* sysdeps/unix/sysv/linux/i386/libm.abilist: Update.
* sysdeps/unix/sysv/linux/ia64/libm.abilist: Update.
* sysdeps/unix/sysv/linux/m68k/coldfire/libm.abilist: Update.
* sysdeps/unix/sysv/linux/m68k/m680x0/libm.abilist: Update.
* sysdeps/unix/sysv/linux/microblaze/libm.abilist: Update.
* sysdeps/unix/sysv/linux/mips/mips32/libm.abilist: Update.
* sysdeps/unix/sysv/linux/mips/mips64/libm.abilist: Update.
* sysdeps/unix/sysv/linux/nios2/libm.abilist: Update.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libm.abilist: Update.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libm.abilist: Update.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm-le.abilist: Update.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm.abilist: Update.
* sysdeps/unix/sysv/linux/s390/s390-32/libm.abilist: Update.
* sysdeps/unix/sysv/linux/s390/s390-64/libm.abilist: Update.
* sysdeps/unix/sysv/linux/sh/libm.abilist: Update.
* sysdeps/unix/sysv/linux/sparc/sparc32/libm.abilist: Update.
* sysdeps/unix/sysv/linux/sparc/sparc64/libm.abilist: Update.
* sysdeps/unix/sysv/linux/x86_64/64/libm.abilist: Update.
* sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Update.
* sysdeps/x86_64/fpu/multiarch/e_exp-avx.c (__exp1): Remove.
(__ieee754_exp): Rename to __exp.
* sysdeps/x86_64/fpu/multiarch/e_exp-fma.c (__exp1): Remove.
(__ieee754_exp): Rename to __exp.
* sysdeps/x86_64/fpu/multiarch/e_exp-fma4.c (__exp1): Remove.
(__ieee754_exp): Rename to __exp.
* sysdeps/x86_64/fpu/multiarch/e_exp.c (__ieee754_exp): Rename to
__exp.
* sysdeps/x86_64/fpu/multiarch/w_exp.c: New file.
This patch fixes the glibc build for i686 with current mainline GCC,
where there are warnings about inconsistent attributes for aliases in
certain files defining libm IFUNCs.
In three of the files, the aliases were defined in terms of internal
symbols such as __sinf, and copied attributes from file-local
declarations of those functions which lacked the nothrow attribute.
Since the nothrow attribute is present on the declarations from
<math.h> (which include declarations of those __-prefixed functions),
the natural fix was to include <math.h> in those files, replacing the
local declarations.
In the other three files, a more complicated __hidden_ver1 call was
involved in the warnings. <math.h> has not been included at this
point and, furthermore, it is included indirectly only later in the
source file after macros have been defined to remap a function name
therein. So there isn't an obvious declaration from which to copy the
attribute and it seems simplest and safest just to add __THROW to the
hidden_ver1 calls.
Tested for i686 (build-many-glibcs.py compilers build for
x86_64-linux-gnu with GCC mainline; full testsuite run with GCC 7).
* sysdeps/i386/i686/fpu/multiarch/e_expf.c [SHARED]: Use __THROW
with __hidden_ver1 call.
* sysdeps/i386/i686/fpu/multiarch/e_log2f.c [SHARED]: Likewise.
* sysdeps/i386/i686/fpu/multiarch/e_logf.c [SHARED]: Likewise.
* sysdeps/i386/i686/fpu/multiarch/s_cosf.c: Include <math.h>.
(__cosf): Do not declare here.
* sysdeps/i386/i686/fpu/multiarch/s_sincosf.c: Include <math.h>.
(__sincosf): Do not declare here.
* sysdeps/i386/i686/fpu/multiarch/s_sinf.c: Include <math.h>.
(__sinf): Do not declare here.
Since _rdtsc intrinsic is supported in GCC 4.9, we can use it for
HP_TIMING_NOW. This patch
1. Create x86 hp-timing.h to replace i686 and x86_64 hp-timing.h.
2. Move MINIMUM_ISA from init-arch.h to isa.h so that x86 hp-timing.h
can check minimum x86 ISA to decide if _rdtsc can be used.
NB: Checking if __i686__ isn't sufficient since __i686__ may not be
defined when building for i686 class processors.
* sysdeps/i386/init-arch.h: Removed.
* sysdeps/i386/i586/init-arch.h: Likewise.
* sysdeps/i386/i686/init-arch.h: Likewise.
* sysdeps/i386/i686/hp-timing.h: Likewise.
* sysdeps/x86_64/hp-timing.h: Likewise.
* sysdeps/i386/isa.h: New file.
* sysdeps/i386/i586/isa.h: Likewise.
* sysdeps/i386/i686/isa.h: Likewise.
* sysdeps/x86_64/isa.h: Likewise.
* sysdeps/x86/hp-timing.h: New file.
* sysdeps/x86/init-arch.h: Include <isa.h>.
After my changes to move various macros, inlines and other content
from math_private.h to more specific headers, many files including
math_private.h no longer need to do so. Furthermore, since the
optimized inlines of various functions have been moved to
include/fenv.h or replaced by use of function names GCC inlines
automatically, a missing math_private.h include where one is
appropriate will reliably cause a build failure rather than possibly
causing code to be less well optimized while still building
successfully. Thus, this patch removes includes of math_private.h
that are now unnecessary. In the case of two RISC-V files, the
include is replaced by one of stdbool.h because the files in question
were relying on math_private.h to get a definition of bool.
Tested for x86_64 and x86, and with build-many-glibcs.py.
* math/fromfp.h: Do not include <math_private.h>.
* math/s_cacosh_template.c: Likewise.
* math/s_casin_template.c: Likewise.
* math/s_casinh_template.c: Likewise.
* math/s_ccos_template.c: Likewise.
* math/s_cproj_template.c: Likewise.
* math/s_fdim_template.c: Likewise.
* math/s_fmaxmag_template.c: Likewise.
* math/s_fminmag_template.c: Likewise.
* math/s_iseqsig_template.c: Likewise.
* math/s_ldexp_template.c: Likewise.
* math/s_nextdown_template.c: Likewise.
* math/w_log1p_template.c: Likewise.
* math/w_scalbln_template.c: Likewise.
* sysdeps/aarch64/fpu/feholdexcpt.c: Likewise.
* sysdeps/aarch64/fpu/fesetround.c: Likewise.
* sysdeps/aarch64/fpu/fgetexcptflg.c: Likewise.
* sysdeps/aarch64/fpu/ftestexcept.c: Likewise.
* sysdeps/aarch64/fpu/s_llrint.c: Likewise.
* sysdeps/aarch64/fpu/s_llrintf.c: Likewise.
* sysdeps/aarch64/fpu/s_lrint.c: Likewise.
* sysdeps/aarch64/fpu/s_lrintf.c: Likewise.
* sysdeps/i386/fpu/s_atanl.c: Likewise.
* sysdeps/i386/fpu/s_f32xaddf64.c: Likewise.
* sysdeps/i386/fpu/s_f32xsubf64.c: Likewise.
* sysdeps/i386/fpu/s_fdim.c: Likewise.
* sysdeps/i386/fpu/s_logbl.c: Likewise.
* sysdeps/i386/fpu/s_rintl.c: Likewise.
* sysdeps/i386/fpu/s_significandl.c: Likewise.
* sysdeps/ia64/fpu/s_matherrf.c: Likewise.
* sysdeps/ia64/fpu/s_matherrl.c: Likewise.
* sysdeps/ieee754/dbl-64/s_atan.c: Likewise.
* sysdeps/ieee754/dbl-64/s_cbrt.c: Likewise.
* sysdeps/ieee754/dbl-64/s_fma.c: Likewise.
* sysdeps/ieee754/dbl-64/s_fmaf.c: Likewise.
* sysdeps/ieee754/flt-32/s_cbrtf.c: Likewise.
* sysdeps/ieee754/k_standardf.c: Likewise.
* sysdeps/ieee754/k_standardl.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_copysignl.c: Likewise.
* sysdeps/ieee754/ldbl-64-128/s_finitel.c: Likewise.
* sysdeps/ieee754/ldbl-64-128/s_fpclassifyl.c: Likewise.
* sysdeps/ieee754/ldbl-64-128/s_isinfl.c: Likewise.
* sysdeps/ieee754/ldbl-64-128/s_isnanl.c: Likewise.
* sysdeps/ieee754/ldbl-64-128/s_signbitl.c: Likewise.
* sysdeps/ieee754/ldbl-96/s_cbrtl.c: Likewise.
* sysdeps/ieee754/ldbl-96/s_fma.c: Likewise.
* sysdeps/ieee754/ldbl-96/s_fmal.c: Likewise.
* sysdeps/ieee754/s_signgam.c: Likewise.
* sysdeps/powerpc/power5+/fpu/s_modf.c: Likewise.
* sysdeps/powerpc/power5+/fpu/s_modff.c: Likewise.
* sysdeps/powerpc/power7/fpu/s_logbf.c: Likewise.
* sysdeps/riscv/rv64/rvd/s_ceil.c: Likewise.
* sysdeps/riscv/rv64/rvd/s_floor.c: Likewise.
* sysdeps/riscv/rv64/rvd/s_nearbyint.c: Likewise.
* sysdeps/riscv/rv64/rvd/s_round.c: Likewise.
* sysdeps/riscv/rv64/rvd/s_roundeven.c: Likewise.
* sysdeps/riscv/rv64/rvd/s_trunc.c: Likewise.
* sysdeps/riscv/rvd/s_finite.c: Likewise.
* sysdeps/riscv/rvd/s_fmax.c: Likewise.
* sysdeps/riscv/rvd/s_fmin.c: Likewise.
* sysdeps/riscv/rvd/s_fpclassify.c: Likewise.
* sysdeps/riscv/rvd/s_isinf.c: Likewise.
* sysdeps/riscv/rvd/s_isnan.c: Likewise.
* sysdeps/riscv/rvd/s_issignaling.c: Likewise.
* sysdeps/riscv/rvf/fegetround.c: Likewise.
* sysdeps/riscv/rvf/feholdexcpt.c: Likewise.
* sysdeps/riscv/rvf/fesetenv.c: Likewise.
* sysdeps/riscv/rvf/fesetround.c: Likewise.
* sysdeps/riscv/rvf/feupdateenv.c: Likewise.
* sysdeps/riscv/rvf/fgetexcptflg.c: Likewise.
* sysdeps/riscv/rvf/ftestexcept.c: Likewise.
* sysdeps/riscv/rvf/s_ceilf.c: Likewise.
* sysdeps/riscv/rvf/s_finitef.c: Likewise.
* sysdeps/riscv/rvf/s_floorf.c: Likewise.
* sysdeps/riscv/rvf/s_fmaxf.c: Likewise.
* sysdeps/riscv/rvf/s_fminf.c: Likewise.
* sysdeps/riscv/rvf/s_fpclassifyf.c: Likewise.
* sysdeps/riscv/rvf/s_isinff.c: Likewise.
* sysdeps/riscv/rvf/s_isnanf.c: Likewise.
* sysdeps/riscv/rvf/s_issignalingf.c: Likewise.
* sysdeps/riscv/rvf/s_nearbyintf.c: Likewise.
* sysdeps/riscv/rvf/s_roundevenf.c: Likewise.
* sysdeps/riscv/rvf/s_roundf.c: Likewise.
* sysdeps/riscv/rvf/s_truncf.c: Likewise.
* sysdeps/riscv/rv64/rvd/s_rint.c: Include <stdbool.h> instead of
<math_private.h>.
* sysdeps/riscv/rvf/s_rintf.c: Likewise.
When elf_machine_runtime_setup is called to set up resolver, it should
use _dl_runtime_resolve_shstk or _dl_runtime_profile_shstk if SHSTK is
enabled by kernel.
Tested on i686 with and without --enable-cet as well as on CET emulator
with --enable-cet.
[BZ #23716]
* sysdeps/i386/dl-cet.c: Removed.
* sysdeps/i386/dl-machine.h (_dl_runtime_resolve_shstk): New
prototype.
(_dl_runtime_profile_shstk): Likewise.
(elf_machine_runtime_setup): Use _dl_runtime_profile_shstk or
_dl_runtime_resolve_shstk if SHSTK is enabled by kernel.
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
The algorithm is exp(y * log(x)), where log(x) is computed with about
1.3*2^-68 relative error (1.5*2^-68 without fma), returning the result
in two doubles, and the exp part uses the same algorithm (and lookup
tables) as exp, but takes the input as two doubles and a sign (to handle
negative bases with odd integer exponent). The __exp1 internal symbol
is no longer necessary.
There is separate code path when fma is not available but the worst case
error is about 0.54 ULP in both cases. The lookup table and consts for
log are 4168 bytes. The .rodata+.text is decreased by 37908 bytes on
aarch64. The non-nearest rounding error is less than 1 ULP.
Improvements on Cortex-A72 compared to current glibc master:
pow thruput: 2.40x in [0.01 11.1]x[0.01 11.1]
pow latency: 1.84x in [0.01 11.1]x[0.01 11.1]
Tested on
aarch64-linux-gnu (defined __FP_FAST_FMA, TOINT_INTRINSICS) and
arm-linux-gnueabihf (!defined __FP_FAST_FMA, !TOINT_INTRINSICS) and
x86_64-linux-gnu (!defined __FP_FAST_FMA, !TOINT_INTRINSICS) and
powerpc64le-linux-gnu (defined __FP_FAST_FMA, !TOINT_INTRINSICS) targets.
* NEWS: Mention pow improvements.
* math/Makefile (type-double-routines): Add e_pow_log_data.
* sysdeps/generic/math_private.h (__exp1): Remove.
* sysdeps/i386/fpu/e_pow_log_data.c: New file.
* sysdeps/ia64/fpu/e_pow_log_data.c: New file.
* sysdeps/ieee754/dbl-64/Makefile (CFLAGS-e_pow.c): Allow fma
contraction.
* sysdeps/ieee754/dbl-64/e_exp.c (__exp1): Remove.
(exp_inline): Remove.
(__ieee754_exp): Only single double input is handled.
* sysdeps/ieee754/dbl-64/e_pow.c: Rewrite.
* sysdeps/ieee754/dbl-64/e_pow_log_data.c: New file.
* sysdeps/ieee754/dbl-64/math_config.h (issignaling_inline): Define.
(__pow_log_data): Define.
* sysdeps/ieee754/dbl-64/upow.h: Remove.
* sysdeps/ieee754/dbl-64/upow.tbl: Remove.
* sysdeps/m68k/m680x0/fpu/e_pow_log_data.c: New file.
* sysdeps/x86_64/fpu/multiarch/Makefile (CFLAGS-e_pow-fma.c): Allow fma
contraction.
(CFLAGS-e_pow-fma4.c): Likewise.
Continuing the move to use, within libm, public names for libm
functions that can be inlined as built-in functions on many
architectures, this patch moves calls to __rint functions to call the
corresponding rint names instead, with asm redirection to __rint when
the calls are not inlined. The x86_64 math_private.h is removed as no
longer useful after this patch.
This patch is relative to a tree with my floor patch
<https://sourceware.org/ml/libc-alpha/2018-09/msg00148.html> applied,
and much the same considerations arise regarding possibly replacing an
IFUNC call with a direct inline expansion.
Tested for x86_64, and with build-many-glibcs.py.
* include/math.h [!_ISOMAC && !(__FINITE_MATH_ONLY__ &&
__FINITE_MATH_ONLY__ > 0) && !NO_MATH_REDIRECT] (rint): Redirect
using MATH_REDIRECT.
* sysdeps/aarch64/fpu/s_rint.c: Define NO_MATH_REDIRECT before
header inclusion.
* sysdeps/aarch64/fpu/s_rintf.c: Likewise.
* sysdeps/alpha/fpu/s_rint.c: Likewise.
* sysdeps/alpha/fpu/s_rintf.c: Likewise.
* sysdeps/i386/fpu/s_rintl.c: Likewise.
* sysdeps/ieee754/dbl-64/s_rint.c: Likewise.
* sysdeps/ieee754/dbl-64/wordsize-64/s_rint.c: Likewise.
* sysdeps/ieee754/float128/s_rintf128.c: Likewise.
* sysdeps/ieee754/flt-32/s_rintf.c: Likewise.
* sysdeps/ieee754/ldbl-128/s_rintl.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_rintl.c: Likewise.
* sysdeps/m68k/coldfire/fpu/s_rint.c: Likewise.
* sysdeps/m68k/coldfire/fpu/s_rintf.c: Likewise.
* sysdeps/m68k/m680x0/fpu/s_rint.c: Likewise.
* sysdeps/m68k/m680x0/fpu/s_rintf.c: Likewise.
* sysdeps/m68k/m680x0/fpu/s_rintl.c: Likewise.
* sysdeps/powerpc/fpu/s_rint.c: Likewise.
* sysdeps/powerpc/fpu/s_rintf.c: Likewise.
* sysdeps/riscv/rv64/rvd/s_rint.c: Likewise.
* sysdeps/riscv/rvf/s_rintf.c: Likewise.
* sysdeps/sparc/sparc32/sparcv9/fpu/multiarch/s_rint.c: Likewise.
* sysdeps/sparc/sparc32/sparcv9/fpu/multiarch/s_rintf.c: Likewise.
* sysdeps/sparc/sparc64/fpu/multiarch/s_rint.c: Likewise.
* sysdeps/sparc/sparc64/fpu/multiarch/s_rintf.c: Likewise.
* sysdeps/x86_64/fpu/multiarch/s_rint.c: Likewise.
* sysdeps/x86_64/fpu/multiarch/s_rintf.c: Likewise.
* sysdeps/x86_64/fpu/math_private.h: Remove file.
* math/e_scalb.c (invalid_fn): Use rint functions instead of
__rint variants.
* math/e_scalbf.c (invalid_fn): Likewise.
* math/e_scalbl.c (invalid_fn): Likewise.
* sysdeps/ieee754/dbl-64/e_gamma_r.c (__ieee754_gamma_r):
Likewise.
* sysdeps/ieee754/flt-32/e_gammaf_r.c (__ieee754_gammaf_r):
Likewise.
* sysdeps/ieee754/k_standard.c (__kernel_standard): Likewise.
* sysdeps/ieee754/k_standardl.c (__kernel_standard_l): Likewise.
* sysdeps/ieee754/ldbl-128/e_gammal_r.c (__ieee754_gammal_r):
Likewise.
* sysdeps/ieee754/ldbl-128ibm/e_gammal_r.c (__ieee754_gammal_r):
Likewise.
* sysdeps/ieee754/ldbl-96/e_gammal_r.c (__ieee754_gammal_r):
Likewise.
* sysdeps/powerpc/powerpc32/fpu/s_llrint.c (__llrint): Likewise.
* sysdeps/powerpc/powerpc32/fpu/s_llrintf.c (__llrintf): Likewise.
Similar algorithm is used as in log: log2(2^k x) = k + log2(c) + log2(x/c)
where the last term is approximated by a polynomial of x/c - 1, the first
order coefficient is about 1/ln2 in this case.
There is separate code path when fma instruction is not available for
computing x/c - 1 precisely, for which the table size is doubled.
The worst case error is 0.547 ULP (0.55 without fma), the read only
global data size is 1168 bytes (2192 without fma) on aarch64. The
non-nearest rounding error is less than 1 ULP.
Improvements on Cortex-A72 compared to current glibc master:
log2 thruput: 2.00x in [0.01 11.1]
log2 latency: 2.04x in [0.01 11.1]
log2 thruput: 2.17x in [0.999 1.001]
log2 latency: 2.88x in [0.999 1.001]
Tested on
aarch64-linux-gnu (defined __FP_FAST_FMA)
arm-linux-gnueabihf (!defined __FP_FAST_FMA)
x86_64-linux-gnu (!defined __FP_FAST_FMA)
powerpc64le-linxu-gnu (defined __FP_FAST_FMA)
targets.
* NEWS: Mention log2 improvements.
* math/Makefile (type-double-routines): Add e_log2_data.
* sysdeps/i386/fpu/e_log2_data.c: New file.
* sysdeps/ia64/fpu/e_log2_data.c: New file.
* sysdeps/ieee754/dbl-64/e_log2.c: Rewrite.
* sysdeps/ieee754/dbl-64/e_log2_data.c: New file.
* sysdeps/ieee754/dbl-64/math_config.h (__log2_data): Add.
* sysdeps/ieee754/dbl-64/wordsize-64/e_log2.c: Remove.
* sysdeps/m68k/m680x0/fpu/e_log2_data.c: New file.
Optimized log using carefully generated lookup table with 1/c and log(c)
values for small intervalls around 1. The log(c) is very near a double
precision value, it has about 62 bits precision. The algorithm is
log(2^k x) = k log(2) + log(c) + log(x/c), where the last term is
approximated by a polynomial of x/c - 1. Near 1 a single polynomial of
x - 1 is used.
There is separate code path when fma instruction is not available for
computing x/c - 1 precisely, in which case the table size is doubled.
The code uses __builtin_fma under __FP_FAST_FMA to ensure it is inlined
as an instruction.
With the default configuration settings the worst case error is 0.519 ULP
(and 0.520 without fma), the rodata size is 2192 bytes (4240 without fma).
The non-nearest rounding error is less than 1 ULP.
Improvements on Cortex-A72 compared to current glibc master:
log thruput: 3.28x in [0.01 11.1]
log latency: 2.23x in [0.01 11.1]
log thruput: 1.56x in [0.999 1.001]
log latency: 1.57x in [0.999 1.001]
Tested on
aarch64-linux-gnu (defined __FP_FAST_FMA)
arm-linux-gnueabihf (!defined __FP_FAST_FMA)
x86_64-linux-gnu (!defined __FP_FAST_FMA)
powerpc64le-linux-gnu (defined __FP_FAST_FMA)
targets.
* NEWS: Mention log improvement.
* math/Makefile (type-double-routines): Add e_log_data.
* sysdeps/i386/fpu/e_log_data.c: New file.
* sysdeps/ia64/fpu/e_log_data.c: New file.
* sysdeps/ieee754/dbl-64/e_log.c: Rewrite.
* sysdeps/ieee754/dbl-64/e_log_data.c: New file.
* sysdeps/ieee754/dbl-64/math_config.h (__log_data): Add.
* sysdeps/ieee754/dbl-64/ulog.h: Remove.
* sysdeps/ieee754/dbl-64/ulog.tbl: Remove.
* sysdeps/m68k/m680x0/fpu/e_log_data.c: New file.
Wrapping the _start function with ENTRY and END to insert ENDBR32 at
function entry when CET is enabled. Since _start now includes CFI,
without "cfi_undefined (eip)", unwinder may not terminate at _start
and we will get
Program received signal SIGSEGV, Segmentation fault.
0xf7dc661e in ?? () from /lib/libgcc_s.so.1
Missing separate debuginfos, use: dnf debuginfo-install libgcc-8.2.1-3.0.fc28.i686
(gdb) bt
#0 0xf7dc661e in ?? () from /lib/libgcc_s.so.1
#1 0xf7dc7c18 in _Unwind_Backtrace () from /lib/libgcc_s.so.1
#2 0xf7f0d809 in __GI___backtrace (array=array@entry=0xffffc7d0,
size=size@entry=20) at ../sysdeps/i386/backtrace.c:127
#3 0x08049254 in compare (p1=p1@entry=0xffffcad0, p2=p2@entry=0xffffcad4)
at backtrace-tst.c:12
#4 0xf7e2a28c in msort_with_tmp (p=p@entry=0xffffca5c, b=b@entry=0xffffcad0,
n=n@entry=2) at msort.c:65
#5 0xf7e29f64 in msort_with_tmp (n=2, b=0xffffcad0, p=0xffffca5c)
at msort.c:53
#6 msort_with_tmp (p=p@entry=0xffffca5c, b=b@entry=0xffffcad0, n=n@entry=5)
at msort.c:53
#7 0xf7e29f64 in msort_with_tmp (n=5, b=0xffffcad0, p=0xffffca5c)
at msort.c:53
#8 msort_with_tmp (p=p@entry=0xffffca5c, b=b@entry=0xffffcad0, n=n@entry=10)
at msort.c:53
#9 0xf7e29f64 in msort_with_tmp (n=10, b=0xffffcad0, p=0xffffca5c)
at msort.c:53
#10 msort_with_tmp (p=p@entry=0xffffca5c, b=b@entry=0xffffcad0, n=n@entry=20)
at msort.c:53
#11 0xf7e2a5b6 in msort_with_tmp (n=20, b=0xffffcad0, p=0xffffca5c)
at msort.c:297
#12 __GI___qsort_r (b=b@entry=0xffffcad0, n=n@entry=20, s=s@entry=4,
cmp=cmp@entry=0x8049230 <compare>, arg=arg@entry=0x0) at msort.c:297
#13 0xf7e2a84d in __GI_qsort (b=b@entry=0xffffcad0, n=n@entry=20, s=s@entry=4,
cmp=cmp@entry=0x8049230 <compare>) at msort.c:308
#14 0x080490f6 in main (argc=2, argv=0xffffcbd4) at backtrace-tst.c:39
FAIL: debug/backtrace-tst
[BZ #23606]
* sysdeps/i386/start.S: Include <sysdep.h>
(_start): Use ENTRY/END to insert ENDBR32 at entry when CET is
enabled. Add cfi_undefined (eip).
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Optimized exp and exp2 implementations using a lookup table for
fractional powers of 2. There are several variants, see e_exp_data.c,
they can be selected by modifying math_config.h allowing different
tradeoffs.
The default selection should be acceptable as generic libm code.
Worst case error is 0.509 ULP for exp and 0.507 ULP for exp2, on
aarch64 the rodata size is 2160 bytes, shared between exp and exp2.
On aarch64 .text + .rodata size decreased by 24912 bytes.
The non-nearest rounding error is less than 1 ULP even on targets
without efficient round implementation (although the error rate is
higher in that case). Targets with single instruction, rounding mode
independent, to nearest integer rounding and conversion can use them
by setting TOINT_INTRINSICS and adding the necessary code to their
math_private.h.
The __exp1 code uses the same algorithm, so the error bound of pow
increased a bit.
New double precision error handling code was added following the
style of the single precision error handling code.
Improvements on Cortex-A72 compared to current glibc master:
exp thruput: 1.61x in [-9.9 9.9]
exp latency: 1.53x in [-9.9 9.9]
exp thruput: 1.13x in [0.5 1]
exp latency: 1.30x in [0.5 1]
exp2 thruput: 2.03x in [-9.9 9.9]
exp2 latency: 1.64x in [-9.9 9.9]
For small (< 1) inputs the current exp code uses a separate algorithm
so the speed up there is less.
Was tested on
aarch64-linux-gnu (TOINT_INTRINSICS, fma contraction) and
arm-linux-gnueabihf (!TOINT_INTRINSICS, no fma contraction) and
x86_64-linux-gnu (!TOINT_INTRINSICS, no fma contraction) and
powerpc64le-linux-gnu (!TOINT_INTRINSICS, fma contraction) targets,
only non-nearest rounding ulp errors increase and they are within
acceptable bounds (ulp updates are in separate patches).
* NEWS: Mention exp and exp2 improvements.
* math/Makefile (libm-support): Remove t_exp.
(type-double-routines): Add math_err and e_exp_data.
* sysdeps/aarch64/libm-test-ulps: Update.
* sysdeps/arm/libm-test-ulps: Update.
* sysdeps/i386/fpu/e_exp_data.c: New file.
* sysdeps/i386/fpu/math_err.c: New file.
* sysdeps/i386/fpu/t_exp.c: Remove.
* sysdeps/ia64/fpu/e_exp_data.c: New file.
* sysdeps/ia64/fpu/math_err.c: New file.
* sysdeps/ia64/fpu/t_exp.c: Remove.
* sysdeps/ieee754/dbl-64/e_exp.c: Rewrite.
* sysdeps/ieee754/dbl-64/e_exp2.c: Rewrite.
* sysdeps/ieee754/dbl-64/e_exp_data.c: New file.
* sysdeps/ieee754/dbl-64/e_pow.c (__ieee754_pow): Update error bound.
* sysdeps/ieee754/dbl-64/eexp.tbl: Remove.
* sysdeps/ieee754/dbl-64/math_config.h: New file.
* sysdeps/ieee754/dbl-64/math_err.c: New file.
* sysdeps/ieee754/dbl-64/t_exp.c: Remove.
* sysdeps/ieee754/dbl-64/t_exp2.h: Remove.
* sysdeps/ieee754/dbl-64/uexp.h: Remove.
* sysdeps/ieee754/dbl-64/uexp.tbl: Remove.
* sysdeps/m68k/m680x0/fpu/e_exp_data.c: New file.
* sysdeps/m68k/m680x0/fpu/math_err.c: New file.
* sysdeps/m68k/m680x0/fpu/t_exp.c: Remove.
* sysdeps/powerpc/fpu/libm-test-ulps: Update.
* sysdeps/x86_64/fpu/libm-test-ulps: Update.
On some architectures, the parts of math_private.h relating to the
floating-point environment are in a separate file fenv_private.h
included from math_private.h. As this is purely an
architecture-specific convention used by several architectures,
however, all such architectures still need their own math_private.h,
even if it has nothing to do beyond #include <fenv_private.h> and
peculiarity of including the i386 file directly instead of having a
shared file in sysdeps/x86.
This patch makes the fenv_private.h name an architecture-independent
convention in glibc. The include of fenv_private.h from
math_private.h becomes architecture-independent (until callers are
updated to include fenv_private.h directly so the include from
math_private.h is no longer needed). Some architecture math_private.h
headers are removed if no longer needed, or renamed to fenv_private.h
if all they define belongs in that header; architecture fenv_private.h
headers now do require #include_next <fenv_private.h>. The i386
fenv_private.h file moves to sysdeps/x86/fpu/ to reflect how it is
actually shared with x86_64. The generic math_private.h gets a new
include of <stdbool.h>, as needed for bool in some prototypes in that
header (previously that was indirectly included via include/fenv.h,
which now only gets included too late in math_private.h, after those
prototypes).
Tested for x86_64 and x86, and tested with build-many-glibcs.py that
installed stripped shared libraries are unchanged by the patch.
* sysdeps/aarch64/fpu/fenv_private.h: New file. Based on ....
* sysdeps/aarch64/fpu/math_private.h: ... this file. All contents
moved to fenv_private.h except for ...
(TOINT_INTRINSICS): Kept in math_private.h.
(roundtoint): Likewise.
(converttoint): Likewise.
* sysdeps/arm/fenv_private.h: Change multiple-include guard to
[ARM_FENV_PRIVATE_H]. Include next <fenv_private.h>.
* sysdeps/arm/math_private.h: Remove.
* sysdeps/generic/fenv_private.h: New file. Contents moved from
....
* sysdeps/generic/math_private.h: ... this file. Include
<stdbool.h>. Do not include <fenv.h> or <get-rounding-mode.h>.
Include <fenv_private.h>. Remove functions and macros moved to
fenv_private.h.
* sysdeps/i386/fpu/math_private.h: Remove.
* sysdeps/mips/math_private.h: Move to ....
* sysdeps/mips/fpu/fenv_private.h: ... here. Change
multiple-include guard to [MIPS_FENV_PRIVATE_H]. Remove
[__mips_hard_float] conditional. Include next <fenv_private.h>.
* sysdeps/powerpc/fpu/fenv_private.h: Change multiple-include
guard to [POWERPC_FENV_PRIVATE_H]. Include next <fenv_private.h>.
* sysdeps/powerpc/fpu/math_private.h: Do not include
<fenv_private.h>.
* sysdeps/riscv/rvf/math_private.h: Move to ....
* sysdeps/riscv/rvf/fenv_private.h: ... here. Change
multiple-include guard to [RISCV_FENV_PRIVATE_H]. Include next
<fenv_private.h>.
* sysdeps/sparc/fpu/fenv_private.h: Change multiple-include guard
to [SPARC_FENV_PRIVATE_H]. Include next <fenv_private.h>.
* sysdeps/sparc/fpu/math_private.h: Remove.
* sysdeps/i386/fpu/fenv_private.h: Move to ....
* sysdeps/x86/fpu/fenv_private.h: ... here. Change
multiple-include guard to [X86_FENV_PRIVATE_H]. Include next
<fenv_private.h>.
* sysdeps/x86_64/fpu/math_private.h: Do not include
<sysdeps/i386/fpu/fenv_private.h>.
Continuing moving macros out of math-tests.h to smaller headers
following typo-proof conventions instead of using #ifndef, this patch
moves the SNAN_TESTS_* macros for individual types out to their own
sysdeps header (while the type-generic SNAN_TESTS wrapper for those
macros remains in math-tests.h).
Tested for x86_64 and x86, and with build-many-glibcs.py.
* sysdeps/generic/math-tests-snan.h: New file.
* sysdeps/generic/math-tests.h: Include <math-tests-snan.h>.
(SNAN_TESTS_float): Do not define here.
(SNAN_TESTS_double): Likewise.
(SNAN_TESTS_long_double): Likewise.
(SNAN_TESTS_float128): Likewise.
* sysdeps/i386/fpu/math-tests-snan.h: New file.
* sysdeps/i386/fpu/math-tests.h: Remove file.
* sysdeps/ia64/math-tests-snan.h: New file.
* sysdeps/ia64/math-tests.h: Remove file.
* sysdeps/x86/math-tests.h: Likewise.
* sysdeps/x86_64/fpu/math-tests-snan.h: New file.
__fentry__ symbol is currently not defined for other architectures.
Attempts to introduce it cause abicheck to fail, because it will be
available since 2.29 earliest, and not 2.13, which is the case for
Intel. With the new code, abicheck passes for i686-linux-gnu,
x86_64-linux-gnu and x86_64-linux-gnu32 triples.
ChangeLog:
* stdlib/Versions: Remove __fentry__.
* sysdeps/i386/Versions: Add __fentry__.
* sysdeps/x86_64/Versions: Add __fentry__.
There is no need to include <init-arch.h> in assembly codes since all
x86 IFUNC selector functions are written in C. Tested on i686 and
x86-64. There is no code change in libc.so, ld.so and libmvec.so.
* sysdeps/i386/i686/multiarch/bzero-ia32.S: Don't include
<init-arch.h>.
* sysdeps/x86_64/fpu/multiarch/svml_d_sin8_core-avx2.S: Likewise.
* sysdeps/x86_64/fpu/multiarch/svml_s_expf16_core-avx2.S: Likewise.
* sysdeps/x86_64/multiarch/memset-sse2-unaligned-erms.S: Likewise.
This will be used to record the current shadow stack base for shadow
stack switching by getcontext, makecontext, setcontext and swapcontext.
If the target shadow stack base is the same as the current shadow stack
base, we unwind the shadow stack. Otherwise it is a stack switch and
we look for a restore token to restore the target shadow stack.
* sysdeps/i386/nptl/tcb-offsets.sym (SSP_BASE_OFFSET): New.
* sysdeps/i386/nptl/tls.h (tcbhead_t): Replace __glibc_reserved2
with ssp_base.
* sysdeps/x86_64/nptl/tcb-offsets.sym (SSP_BASE_OFFSET): New.
* sysdeps/x86_64/nptl/tls.h (tcbhead_t): Replace __glibc_reserved2
with ssp_base.
i386 add_n.S and sub_n.S use a trick to implment jump tables with LEA.
We can't use conditional branches nor normal jump tables since jump
table entries use EFLAGS set by jump table index. This patch adds
_CET_ENDBR to indirect jump targets and adjust destination for
_CET_ENDBR.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* sysdeps/i386/add_n.S: Include <sysdep.h>, instead of
"sysdep.h".
(__mpn_add_n): Save and restore %ebx if IBT is enabed. Add
_CET_ENDBR to indirect jump targets and adjust jump destination
for _CET_ENDBR.
* sysdeps/i386/i686/add_n.S: Include <sysdep.h>, instead of
"sysdep.h".
(__mpn_add_n): Save and restore %ebx if IBT is enabed. Add
_CET_ENDBR to indirect jump targets and adjust jump destination
for _CET_ENDBR.
* sysdeps/i386/sub_n.S: Include <sysdep.h>, instead of
"sysdep.h".
(__mpn_sub_n): Save and restore %ebx if IBT is enabed. Add
_CET_ENDBR to indirect jump targets and adjust jump destination
for _CET_ENDBR.
Add _CET_ENDBR to functions in crti.S, which are called indirectly, to
support IBT.
Tested on i686 and x86-64.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* sysdeps/i386/crti.S (_init): Add _CET_ENDBR.
(_fini): Likewise.
* sysdeps/x86_64/crti.S (_init): Likewise.
(_fini): Likewise.
Intel Control-flow Enforcement Technology (CET) instructions:
https://software.intel.com/sites/default/files/managed/4d/2a/control-flow-en
forcement-technology-preview.pdf
includes Indirect Branch Tracking (IBT) and Shadow Stack (SHSTK).
GNU_PROPERTY_X86_FEATURE_1_IBT is added to GNU program property to
indicate that all executable sections are compatible with IBT when
ENDBR instruction starts each valid target where an indirect branch
instruction can land. Linker sets GNU_PROPERTY_X86_FEATURE_1_IBT on
output only if it is set on all relocatable inputs.
On an IBT capable processor, the following steps should be taken:
1. When loading an executable without an interpreter, enable IBT and
lock IBT if GNU_PROPERTY_X86_FEATURE_1_IBT is set on the executable.
2. When loading an executable with an interpreter, enable IBT if
GNU_PROPERTY_X86_FEATURE_1_IBT is set on the interpreter.
a. If GNU_PROPERTY_X86_FEATURE_1_IBT isn't set on the executable,
disable IBT.
b. Lock IBT.
3. If IBT is enabled, when loading a shared object without
GNU_PROPERTY_X86_FEATURE_1_IBT:
a. If legacy interwork is allowed, then mark all pages in executable
PT_LOAD segments in legacy code page bitmap. Failure of legacy code
page bitmap allocation causes an error.
b. If legacy interwork isn't allowed, it causes an error.
GNU_PROPERTY_X86_FEATURE_1_SHSTK is added to GNU program property to
indicate that all executable sections are compatible with SHSTK where
return address popped from shadow stack always matches return address
popped from normal stack. Linker sets GNU_PROPERTY_X86_FEATURE_1_SHSTK
on output only if it is set on all relocatable inputs.
On a SHSTK capable processor, the following steps should be taken:
1. When loading an executable without an interpreter, enable SHSTK if
GNU_PROPERTY_X86_FEATURE_1_SHSTK is set on the executable.
2. When loading an executable with an interpreter, enable SHSTK if
GNU_PROPERTY_X86_FEATURE_1_SHSTK is set on interpreter.
a. If GNU_PROPERTY_X86_FEATURE_1_SHSTK isn't set on the executable
or any shared objects loaded via the DT_NEEDED tag, disable SHSTK.
b. Otherwise lock SHSTK.
3. After SHSTK is enabled, it is an error to load a shared object
without GNU_PROPERTY_X86_FEATURE_1_SHSTK.
To enable CET support in glibc, --enable-cet is required to configure
glibc. When CET is enabled, both compiler and assembler must support
CET. Otherwise, it is a configure-time error.
To support CET run-time control,
1. _dl_x86_feature_1 is added to the writable ld.so namespace to indicate
if IBT or SHSTK are enabled at run-time. It should be initialized by
init_cpu_features.
2. For dynamic executables:
a. A l_cet field is added to struct link_map to indicate if IBT or
SHSTK is enabled in an ELF module. _dl_process_pt_note or
_rtld_process_pt_note is called to process PT_NOTE segment for
GNU program property and set l_cet.
b. _dl_open_check is added to check IBT and SHSTK compatibilty when
dlopening a shared object.
3. Replace i386 _dl_runtime_resolve and _dl_runtime_profile with
_dl_runtime_resolve_shstk and _dl_runtime_profile_shstk, respectively if
SHSTK is enabled.
CET run-time control can be changed via GLIBC_TUNABLES with
$ export GLIBC_TUNABLES=glibc.tune.x86_shstk=[permissive|on|off]
$ export GLIBC_TUNABLES=glibc.tune.x86_ibt=[permissive|on|off]
1. permissive: SHSTK is disabled when dlopening a legacy ELF module.
2. on: IBT or SHSTK are always enabled, regardless if there are IBT or
SHSTK bits in GNU program property.
3. off: IBT or SHSTK are always disabled, regardless if there are IBT or
SHSTK bits in GNU program property.
<cet.h> from CET-enabled GCC is automatically included by assembly codes
to add GNU_PROPERTY_X86_FEATURE_1_IBT and GNU_PROPERTY_X86_FEATURE_1_SHSTK
to GNU program property. _CET_ENDBR is added at the entrance of all
assembly functions whose address may be taken. _CET_NOTRACK is used to
insert NOTRACK prefix with indirect jump table to support IBT. It is
defined as notrack when _CET_NOTRACK is defined in <cet.h>.
[BZ #21598]
* configure.ac: Add --enable-cet.
* configure: Regenerated.
* elf/Makefille (all-built-dso): Add a comment.
* elf/dl-load.c (filebuf): Moved before "dynamic-link.h".
Include <dl-prop.h>.
(_dl_map_object_from_fd): Call _dl_process_pt_note on PT_NOTE
segment.
* elf/dl-open.c: Include <dl-prop.h>.
(dl_open_worker): Call _dl_open_check.
* elf/rtld.c: Include <dl-prop.h>.
(dl_main): Call _rtld_process_pt_note on PT_NOTE segment. Call
_rtld_main_check.
* sysdeps/generic/dl-prop.h: New file.
* sysdeps/i386/dl-cet.c: Likewise.
* sysdeps/unix/sysv/linux/x86/cpu-features.c: Likewise.
* sysdeps/unix/sysv/linux/x86/dl-cet.h: Likewise.
* sysdeps/x86/cet-tunables.h: Likewise.
* sysdeps/x86/check-cet.awk: Likewise.
* sysdeps/x86/configure: Likewise.
* sysdeps/x86/configure.ac: Likewise.
* sysdeps/x86/dl-cet.c: Likewise.
* sysdeps/x86/dl-procruntime.c: Likewise.
* sysdeps/x86/dl-prop.h: Likewise.
* sysdeps/x86/libc-start.h: Likewise.
* sysdeps/x86/link_map.h: Likewise.
* sysdeps/i386/dl-trampoline.S (_dl_runtime_resolve): Add
_CET_ENDBR.
(_dl_runtime_profile): Likewise.
(_dl_runtime_resolve_shstk): New.
(_dl_runtime_profile_shstk): Likewise.
* sysdeps/linux/x86/Makefile (sysdep-dl-routines): Add dl-cet
if CET is enabled.
(CFLAGS-.o): Add -fcf-protection if CET is enabled.
(CFLAGS-.os): Likewise.
(CFLAGS-.op): Likewise.
(CFLAGS-.oS): Likewise.
(asm-CPPFLAGS): Add -fcf-protection -include cet.h if CET
is enabled.
(tests-special): Add $(objpfx)check-cet.out.
(cet-built-dso): New.
(+$(cet-built-dso:=.note)): Likewise.
(common-generated): Add $(cet-built-dso:$(common-objpfx)%=%.note).
($(objpfx)check-cet.out): New.
(generated): Add check-cet.out.
* sysdeps/x86/cpu-features.c: Include <dl-cet.h> and
<cet-tunables.h>.
(TUNABLE_CALLBACK (set_x86_ibt)): New prototype.
(TUNABLE_CALLBACK (set_x86_shstk)): Likewise.
(init_cpu_features): Call get_cet_status to check CET status
and update dl_x86_feature_1 with CET status. Call
TUNABLE_CALLBACK (set_x86_ibt) and TUNABLE_CALLBACK
(set_x86_shstk). Disable and lock CET in libc.a.
* sysdeps/x86/cpu-tunables.c: Include <cet-tunables.h>.
(TUNABLE_CALLBACK (set_x86_ibt)): New function.
(TUNABLE_CALLBACK (set_x86_shstk)): Likewise.
* sysdeps/x86/sysdep.h (_CET_NOTRACK): New.
(_CET_ENDBR): Define if not defined.
(ENTRY): Add _CET_ENDBR.
* sysdeps/x86/dl-tunables.list (glibc.tune): Add x86_ibt and
x86_shstk.
* sysdeps/x86_64/dl-trampoline.h (_dl_runtime_resolve): Add
_CET_ENDBR.
(_dl_runtime_profile): Likewise.
Save and restore shadow stack pointer in setjmp and longjmp to support
shadow stack in Intel CET. Use feature_1 in tcbhead_t to check if
shadow stack is enabled before saving and restoring shadow stack pointer.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* sysdeps/i386/__longjmp.S: Include <jmp_buf-ssp.h>.
(__longjmp): Restore shadow stack pointer if shadow stack is
enabled, SHADOW_STACK_POINTER_OFFSET is defined and __longjmp
isn't defined for __longjmp_cancel.
* sysdeps/i386/bsd-_setjmp.S: Include <jmp_buf-ssp.h>.
(_setjmp): Save shadow stack pointer if shadow stack is enabled
and SHADOW_STACK_POINTER_OFFSET is defined.
* sysdeps/i386/bsd-setjmp.S: Include <jmp_buf-ssp.h>.
(setjmp): Save shadow stack pointer if shadow stack is enabled
and SHADOW_STACK_POINTER_OFFSET is defined.
* sysdeps/i386/setjmp.S: Include <jmp_buf-ssp.h>.
(__sigsetjmp): Save shadow stack pointer if shadow stack is
enabled and SHADOW_STACK_POINTER_OFFSET is defined.
* sysdeps/unix/sysv/linux/i386/____longjmp_chk.S: Include
<jmp_buf-ssp.h>.
(____longjmp_chk): Restore shadow stack pointer if shadow stack
is enabled and SHADOW_STACK_POINTER_OFFSET is defined.
* sysdeps/unix/sysv/linux/x86/Makefile (gen-as-const-headers):
Remove jmp_buf-ssp.sym.
* sysdeps/unix/sysv/linux/x86_64/____longjmp_chk.S: Include
<jmp_buf-ssp.h>.
(____longjmp_chk): Restore shadow stack pointer if shadow stack
is enabled and SHADOW_STACK_POINTER_OFFSET is defined.
* sysdeps/x86/Makefile (gen-as-const-headers): Add
jmp_buf-ssp.sym.
* sysdeps/x86/jmp_buf-ssp.sym: New dummy file.
* sysdeps/x86_64/__longjmp.S: Include <jmp_buf-ssp.h>.
(__longjmp): Restore shadow stack pointer if shadow stack is
enabled, SHADOW_STACK_POINTER_OFFSET is defined and __longjmp
isn't defined for __longjmp_cancel.
* sysdeps/x86_64/setjmp.S: Include <jmp_buf-ssp.h>.
(__sigsetjmp): Save shadow stack pointer if shadow stack is
enabled and SHADOW_STACK_POINTER_OFFSET is defined.
feature_1 has X86_FEATURE_1_IBT and X86_FEATURE_1_SHSTK bits for CET
run-time control.
CET_ENABLED, IBT_ENABLED and SHSTK_ENABLED are defined to 1 or 0 to
indicate that if CET, IBT and SHSTK are enabled.
<tls-setup.h> is added to set up thread-local data.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
[BZ #22563]
* nptl/pthread_create.c: Include <tls-setup.h>.
(__pthread_create_2_1): Call tls_setup_tcbhead.
* sysdeps/generic/tls-setup.h: New file.
* sysdeps/x86/nptl/tls-setup.h: Likewise.
* sysdeps/i386/nptl/tcb-offsets.sym (FEATURE_1_OFFSET): New.
* sysdeps/x86_64/nptl/tcb-offsets.sym (FEATURE_1_OFFSET):
Likewise.
* sysdeps/i386/nptl/tls.h (tcbhead_t): Rename __glibc_reserved1
to feature_1.
* sysdeps/x86_64/nptl/tls.h (tcbhead_t): Likewise.
* sysdeps/x86/sysdep.h (X86_FEATURE_1_IBT): New.
(X86_FEATURE_1_SHSTK): Likewise.
(CET_ENABLED): Likewise.
(IBT_ENABLED): Likewise.
(SHSTK_ENABLED): Likewise.
sysdeps/i386/nptl/tls.h has
typedef struct
{
void *tcb; /* Pointer to the TCB. Not necessarily the
thread descriptor used by libpthread. */
dtv_t *dtv;
void *self; /* Pointer to the thread descriptor. */
int multiple_threads;
uintptr_t sysinfo;
uintptr_t stack_guard;
uintptr_t pointer_guard;
int gscope_flag;
int __glibc_reserved1;
/* Reservation of some values for the TM ABI. */
void *__private_tm[4];
/* GCC split stack support. */
void *__private_ss;
} tcbhead_t;
The offset of __private_ss is 0x34. But GCC defines
/* We steal the last transactional memory word. */
#define TARGET_THREAD_SPLIT_STACK_OFFSET 0x30
and libgcc/config/i386/morestack.S has
cmpl %gs:0x30,%eax # See if we have enough space.
movl %eax,%gs:0x30 # Save the new stack boundary.
movl %eax,%gs:0x30 # Save the new stack boundary.
movl %ecx,%gs:0x30 # Save new stack boundary.
movl %eax,%gs:0x30
movl %gs:0x30,%eax
movl %eax,%gs:0x30
Since update TARGET_THREAD_SPLIT_STACK_OFFSET changes split stack ABI,
this patch updates tcbhead_t to match GCC.
[BZ #23250]
[BZ #10686]
* sysdeps/i386/nptl/tls.h (tcbhead_t): Change __private_tm[4]
to _private_tm[3] and add __glibc_reserved2.
Add _Static_assert of offset of __private_ss == 0x30.
* sysdeps/x86_64/nptl/tls.h: Add _Static_assert of offset of
__private_ss == 0x40 for ILP32 and == 0x70 for LP64.
Due to the way the conditions were written, the rtld build of strncmp
ended up with no definition of the strncmp symbol at all: The
implementations were renamed for use within an IFUNC resolver, but the
IFUNC resolver itself was missing (because rtld does not use IFUNCs).
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
_init and _fini are special functions provided by glibc for linker to
define DT_INIT and DT_FINI in executable and shared library. They
should never be put in dynamic symbol table. This patch marks them as
hidden to remove them from dynamic symbol table.
Tested with build-many-glibcs.py.
[BZ #23145]
* elf/Makefile (tests-special): Add $(objpfx)check-initfini.out.
($(all-built-dso:=.dynsym): New target.
(common-generated): Add $(all-built-dso:$(common-objpfx)%=%.dynsym).
($(objpfx)check-initfini.out): New target.
(generated): Add check-initfini.out.
* scripts/check-initfini.awk: New file.
* sysdeps/aarch64/crti.S (_init): Mark as hidden.
(_fini): Likewise.
* sysdeps/alpha/crti.S (_init): Mark as hidden.
(_fini): Likewise.
* sysdeps/arm/crti.S (_init): Mark as hidden.
(_fini): Likewise.
* sysdeps/hppa/crti.S (_init): Mark as hidden.
(_fini): Likewise.
* sysdeps/i386/crti.S (_init): Mark as hidden.
(_fini): Likewise.
* sysdeps/ia64/crti.S (_init): Mark as hidden.
(_fini): Likewise.
* sysdeps/m68k/crti.S (_init): Mark as hidden.
(_fini): Likewise.
* sysdeps/microblaze/crti.S (_init): Mark as hidden.
(_fini): Likewise.
* sysdeps/mips/mips32/crti.S (_init): Mark as hidden.
(_fini): Likewise.
* sysdeps/mips/mips64/n32/crti.S (_init): Mark as hidden.
(_fini): Likewise.
* sysdeps/mips/mips64/n64/crti.S (_init): Mark as hidden.
(_fini): Likewise.
* sysdeps/nios2/crti.S (_init): Mark as hidden.
(_fini): Likewise.
* sysdeps/powerpc/powerpc32/crti.S (_init): Mark as hidden.
(_fini): Likewise.
* sysdeps/powerpc/powerpc64/crti.S (_init): Mark as hidden.
(_fini): Likewise.
* sysdeps/s390/s390-32/crti.S (_init): Mark as hidden.
(_fini): Likewise.
* sysdeps/s390/s390-64/crti.S (_init): Mark as hidden.
(_fini): Likewise.
* sysdeps/sh/crti.S (_init): Mark as hidden.
(_fini): Likewise.
* sysdeps/sparc/crti.S (_init): Mark as hidden.
(_fini): Likewise.
* sysdeps/x86_64/crti.S (_init): Mark as hidden.
(_fini): Likewise.
The results are from configuring with --disable-multi-arch, building
with “-march=x86-64 -mtune=generic -mfpmath=sse” and running the
testsuite on a Haswell-era CPU.
Since we have loaded address of PREINIT_FUNCTION into %eax, we can
avoid extra branch to PLT slot.
* sysdeps/i386/crti.S (_init): Replace PREINIT_FUNCTION@PLT
with *%eax in call.
Acked-by: Christian Brauner (Ubuntu) <christian@brauner.io>
This patch continues the math_private.h cleanup by stopping
math_private.h from including math-barriers.h and making the users of
the barrier macros include the latter header directly. No attempt is
made to remove any math_private.h includes that are now unused, except
in strtod_l.c where that is done to avoid line number changes in
assertions, so that installed stripped shared libraries can be
compared before and after the patch. (I think the floating-point
environment support in math_private.h should also move out - some
architectures already have fenv_private.h as an architecture-internal
header included from their math_private.h - and after moving that out
might be a better time to identify unused math_private.h includes.)
Tested for x86_64 and x86, and tested with build-many-glibcs.py that
installed stripped shared libraries are unchanged by the patch.
* sysdeps/generic/math_private.h: Do not include
<math-barriers.h>.
* stdlib/strtod_l.c: Include <math-barriers.h> instead of
<math_private.h>.
* math/fromfp.h: Include <math-barriers.h>.
* math/math-narrow.h: Likewise.
* math/s_nextafter.c: Likewise.
* math/s_nexttowardf.c: Likewise.
* sysdeps/aarch64/fpu/s_llrint.c: Likewise.
* sysdeps/aarch64/fpu/s_llrintf.c: Likewise.
* sysdeps/aarch64/fpu/s_lrint.c: Likewise.
* sysdeps/aarch64/fpu/s_lrintf.c: Likewise.
* sysdeps/i386/fpu/s_nextafterl.c: Likewise.
* sysdeps/i386/fpu/s_nexttoward.c: Likewise.
* sysdeps/i386/fpu/s_nexttowardf.c: Likewise.
* sysdeps/ieee754/dbl-64/e_atan2.c: Likewise.
* sysdeps/ieee754/dbl-64/e_atanh.c: Likewise.
* sysdeps/ieee754/dbl-64/e_exp.c: Likewise.
* sysdeps/ieee754/dbl-64/e_exp2.c: Likewise.
* sysdeps/ieee754/dbl-64/e_j0.c: Likewise.
* sysdeps/ieee754/dbl-64/e_sqrt.c: Likewise.
* sysdeps/ieee754/dbl-64/s_expm1.c: Likewise.
* sysdeps/ieee754/dbl-64/s_fma.c: Likewise.
* sysdeps/ieee754/dbl-64/s_fmaf.c: Likewise.
* sysdeps/ieee754/dbl-64/s_log1p.c: Likewise.
* sysdeps/ieee754/dbl-64/s_nearbyint.c: Likewise.
* sysdeps/ieee754/dbl-64/wordsize-64/s_nearbyint.c: Likewise.
* sysdeps/ieee754/flt-32/e_atanhf.c: Likewise.
* sysdeps/ieee754/flt-32/e_j0f.c: Likewise.
* sysdeps/ieee754/flt-32/s_expm1f.c: Likewise.
* sysdeps/ieee754/flt-32/s_log1pf.c: Likewise.
* sysdeps/ieee754/flt-32/s_nearbyintf.c: Likewise.
* sysdeps/ieee754/flt-32/s_nextafterf.c: Likewise.
* sysdeps/ieee754/k_standardl.c: Likewise.
* sysdeps/ieee754/ldbl-128/e_asinl.c: Likewise.
* sysdeps/ieee754/ldbl-128/e_expl.c: Likewise.
* sysdeps/ieee754/ldbl-128/e_powl.c: Likewise.
* sysdeps/ieee754/ldbl-128/s_fmal.c: Likewise.
* sysdeps/ieee754/ldbl-128/s_nearbyintl.c: Likewise.
* sysdeps/ieee754/ldbl-128/s_nextafterl.c: Likewise.
* sysdeps/ieee754/ldbl-128/s_nexttoward.c: Likewise.
* sysdeps/ieee754/ldbl-128/s_nexttowardf.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/e_asinl.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_fmal.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_nexttoward.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_nexttowardf.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_rintl.c: Likewise.
* sysdeps/ieee754/ldbl-96/e_atanhl.c: Likewise.
* sysdeps/ieee754/ldbl-96/e_j0l.c: Likewise.
* sysdeps/ieee754/ldbl-96/s_fma.c: Likewise.
* sysdeps/ieee754/ldbl-96/s_fmal.c: Likewise.
* sysdeps/ieee754/ldbl-96/s_nexttoward.c: Likewise.
* sysdeps/ieee754/ldbl-96/s_nexttowardf.c: Likewise.
* sysdeps/ieee754/ldbl-opt/s_nexttowardfd.c: Likewise.
* sysdeps/m68k/m680x0/fpu/s_nextafterl.c: Likewise.
This patch continues cleaning up math_private.h by moving the
math_opt_barrier and math_force_eval macros to a separate header
math-barriers.h.
At present, those macros are inside a "#ifndef math_opt_barrier" in
math_private.h to allow architectures to override them and then use
a separate math-barriers.h header, no such #ifndef or #include_next is
needed; architectures just have their own alternative version of
math-barriers.h when providing their own optimized versions that avoid
going through memory unnecessarily. The generic math-barriers.h has a
comment added to document these two macros.
In this patch, math_private.h is made to #include <math-barriers.h>,
so files using these macros do not need updating yet. That is because
of uses of math_force_eval in math_check_force_underflow and
math_check_force_underflow_nonneg, which are still defined in
math_private.h. Once those are moved out to a separate header, that
separate header can be made to include <math-barriers.h>, as can the
other files directly using these barrier macros, and then the include
of <math-barriers.h> from math_private.h can be removed.
Tested for x86_64 and x86. Also tested with build-many-glibcs.py that
installed stripped shared libraries are unchanged by this patch.
* sysdeps/generic/math-barriers.h: New file.
* sysdeps/generic/math_private.h [!math_opt_barrier]
(math_opt_barrier): Move to math-barriers.h.
[!math_opt_barrier] (math_force_eval): Likewise.
* sysdeps/aarch64/fpu/math-barriers.h: New file.
* sysdeps/aarch64/fpu/math_private.h (math_opt_barrier): Move to
math-barriers.h.
(math_force_eval): Likewise.
* sysdeps/alpha/fpu/math-barriers.h: New file.
* sysdeps/alpha/fpu/math_private.h (math_opt_barrier): Move to
math-barriers.h.
(math_force_eval): Likewise.
* sysdeps/x86/fpu/math-barriers.h: New file.
* sysdeps/i386/fpu/fenv_private.h (math_opt_barrier): Move to
math-barriers.h.
(math_force_eval): Likewise.
* sysdeps/m68k/m680x0/fpu/math_private.h: Move to....
* sysdeps/m68k/m680x0/fpu/math-barriers.h: ... here. Adjust
multiple-include guard for rename.
* sysdeps/powerpc/fpu/math-barriers.h: New file.
* sysdeps/powerpc/fpu/math_private.h (math_opt_barrier): Move to
math-barriers.h.
(math_force_eval): Likewise.
This patch continues cleaning up the math_private.h header, which
contains lots of different definitions many of which are only needed
by a limited subset of files using that header (and some of which are
overridden by architectures that only want to override selected parts
of the header), by moving the math_narrow_eval macro out to a separate
math-narrow-eval.h header, only included by those files that need it.
That header is placed in include/ (since it's used in stdlib/, not
just files built in math/, but no sysdeps variants are needed at
present).
Tested for x86_64, and with build-many-glibcs.py. (Installed stripped
shared libraries change because of line numbers in assertions in
strtod_l.c.)
* include/math-narrow-eval.h: New file. Contents moved from ....
* sysdeps/generic/math_private.h: ... here.
(math_narrow_eval): Remove macro. Moved to math-narrow-eval.h.
[FLT_EVAL_METHOD != 0] (excess_precision): Likewise.
* math/s_fdim_template.c: Include <math-narrow-eval.h>.
* stdlib/strtod_l.c: Likewise.
* sysdeps/i386/fpu/s_f32xaddf64.c: Likewise.
* sysdeps/i386/fpu/s_f32xsubf64.c: Likewise.
* sysdeps/i386/fpu/s_fdim.c: Likewise.
* sysdeps/ieee754/dbl-64/e_cosh.c: Likewise.
* sysdeps/ieee754/dbl-64/e_gamma_r.c: Likewise.
* sysdeps/ieee754/dbl-64/e_j1.c: Likewise.
* sysdeps/ieee754/dbl-64/e_jn.c: Likewise.
* sysdeps/ieee754/dbl-64/e_lgamma_r.c: Likewise.
* sysdeps/ieee754/dbl-64/e_sinh.c: Likewise.
* sysdeps/ieee754/dbl-64/gamma_productf.c: Likewise.
* sysdeps/ieee754/dbl-64/k_rem_pio2.c: Likewise.
* sysdeps/ieee754/dbl-64/lgamma_neg.c: Likewise.
* sysdeps/ieee754/dbl-64/s_erf.c: Likewise.
* sysdeps/ieee754/dbl-64/s_llrint.c: Likewise.
* sysdeps/ieee754/dbl-64/s_lrint.c: Likewise.
* sysdeps/ieee754/flt-32/e_coshf.c: Likewise.
* sysdeps/ieee754/flt-32/e_exp2f.c: Likewise.
* sysdeps/ieee754/flt-32/e_expf.c: Likewise.
* sysdeps/ieee754/flt-32/e_gammaf_r.c: Likewise.
* sysdeps/ieee754/flt-32/e_j1f.c: Likewise.
* sysdeps/ieee754/flt-32/e_jnf.c: Likewise.
* sysdeps/ieee754/flt-32/e_lgammaf_r.c: Likewise.
* sysdeps/ieee754/flt-32/e_sinhf.c: Likewise.
* sysdeps/ieee754/flt-32/k_rem_pio2f.c: Likewise.
* sysdeps/ieee754/flt-32/lgamma_negf.c: Likewise.
* sysdeps/ieee754/flt-32/s_erff.c: Likewise.
* sysdeps/ieee754/flt-32/s_llrintf.c: Likewise.
* sysdeps/ieee754/flt-32/s_lrintf.c: Likewise.
* sysdeps/ieee754/ldbl-96/gamma_product.c: Likewise.
Wrap symbol address run-time calculation into a macro and use it
throughout, replacing inline calculations.
There are a couple of variants, most of them different in a functionally
insignificant way. Most calculations are right following RESOLVE_MAP,
at which point either the map or the symbol returned can be checked for
validity as the macro sets either both or neither. In some places both
the symbol and the map has to be checked however.
My initial implementation therefore always checked both, however that
resulted in code larger by as much as 0.3%, as many places know from
elsewhere that no check is needed. I have decided the size growth was
unacceptable.
Having looked closer I realized that it's the map that is the culprit.
Therefore I have modified LOOKUP_VALUE_ADDRESS to accept an additional
boolean argument telling it to access the map without checking it for
validity. This in turn has brought quite nice results, with new code
actually being smaller for i686, and MIPS o32, n32 and little-endian n64
targets, unchanged in size for x86-64 and, unusually, marginally larger
for big-endian MIPS n64, as follows:
i686:
text data bss dec hex filename
152255 4052 192 156499 26353 ld-2.27.9000-base.so
152159 4052 192 156403 262f3 ld-2.27.9000-elf-symbol-value.so
MIPS/o32/el:
text data bss dec hex filename
142906 4396 260 147562 2406a ld-2.27.9000-base.so
142890 4396 260 147546 2405a ld-2.27.9000-elf-symbol-value.so
MIPS/n32/el:
text data bss dec hex filename
142267 4404 260 146931 23df3 ld-2.27.9000-base.so
142171 4404 260 146835 23d93 ld-2.27.9000-elf-symbol-value.so
MIPS/n64/el:
text data bss dec hex filename
149835 7376 408 157619 267b3 ld-2.27.9000-base.so
149787 7376 408 157571 26783 ld-2.27.9000-elf-symbol-value.so
MIPS/o32/eb:
text data bss dec hex filename
142870 4396 260 147526 24046 ld-2.27.9000-base.so
142854 4396 260 147510 24036 ld-2.27.9000-elf-symbol-value.so
MIPS/n32/eb:
text data bss dec hex filename
142019 4404 260 146683 23cfb ld-2.27.9000-base.so
141923 4404 260 146587 23c9b ld-2.27.9000-elf-symbol-value.so
MIPS/n64/eb:
text data bss dec hex filename
149763 7376 408 157547 2676b ld-2.27.9000-base.so
149779 7376 408 157563 2677b ld-2.27.9000-elf-symbol-value.so
x86-64:
text data bss dec hex filename
148462 6452 400 155314 25eb2 ld-2.27.9000-base.so
148462 6452 400 155314 25eb2 ld-2.27.9000-elf-symbol-value.so
[BZ #19818]
* sysdeps/generic/ldsodefs.h (LOOKUP_VALUE_ADDRESS): Add `set'
parameter.
(SYMBOL_ADDRESS): New macro.
[!ELF_FUNCTION_PTR_IS_SPECIAL] (DL_SYMBOL_ADDRESS): Use
SYMBOL_ADDRESS for symbol address calculation.
* elf/dl-runtime.c (_dl_fixup): Likewise.
(_dl_profile_fixup): Likewise.
* elf/dl-symaddr.c (_dl_symbol_address): Likewise.
* elf/rtld.c (dl_main): Likewise.
* sysdeps/aarch64/dl-machine.h (elf_machine_rela): Likewise.
* sysdeps/alpha/dl-machine.h (elf_machine_rela): Likewise.
* sysdeps/arm/dl-machine.h (elf_machine_rel): Likewise.
(elf_machine_rela): Likewise.
* sysdeps/hppa/dl-machine.h (elf_machine_rela): Likewise.
* sysdeps/hppa/dl-symaddr.c (_dl_symbol_address): Likewise.
* sysdeps/i386/dl-machine.h (elf_machine_rel): Likewise.
(elf_machine_rela): Likewise.
* sysdeps/ia64/dl-machine.h (elf_machine_rela): Likewise.
* sysdeps/m68k/dl-machine.h (elf_machine_rela): Likewise.
* sysdeps/microblaze/dl-machine.h (elf_machine_rela): Likewise.
* sysdeps/mips/dl-machine.h (ELF_MACHINE_BEFORE_RTLD_RELOC):
Likewise.
(elf_machine_reloc): Likewise.
(elf_machine_got_rel): Likewise.
* sysdeps/mips/dl-trampoline.c (__dl_runtime_resolve): Likewise.
* sysdeps/nios2/dl-machine.h (elf_machine_rela): Likewise.
* sysdeps/powerpc/powerpc32/dl-machine.h (elf_machine_rela):
Likewise.
* sysdeps/powerpc/powerpc64/dl-machine.h (elf_machine_rela):
Likewise.
* sysdeps/riscv/dl-machine.h (elf_machine_rela): Likewise.
* sysdeps/s390/s390-32/dl-machine.h (elf_machine_rela):
Likewise.
* sysdeps/s390/s390-64/dl-machine.h (elf_machine_rela):
Likewise.
* sysdeps/sh/dl-machine.h (elf_machine_rela): Likewise.
* sysdeps/sparc/sparc32/dl-machine.h (elf_machine_rela):
Likewise.
* sysdeps/sparc/sparc64/dl-machine.h (elf_machine_rela):
Likewise.
* sysdeps/tile/dl-machine.h (elf_machine_rela): Likewise.
* sysdeps/x86_64/dl-machine.h (elf_machine_rela): Likewise.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Contributed by
Agustina Arzille <avarzille@riseup.net>
Amos Jeffries <squid3@treenet.co.nz>
David Michael <fedora.dm0@gmail.com>
Marco Gerards <marco@gnu.org>
Marcus Brinkmann <marcus@gnu.org>
Neal H. Walfield <neal@gnu.org>
Pino Toscano <toscano.pino@tiscali.it>
Richard Braun <rbraun@sceen.net>
Roland McGrath <roland@gnu.org>
Samuel Thibault <samuel.thibault@ens-lyon.org>
Thomas DiModica <ricinwich@yahoo.com>
Thomas Schwinge <tschwinge@gnu.org>
* htl: New directory.
* sysdeps/htl: New directory.
* sysdeps/hurd/htl: New directory.
* sysdeps/i386/htl: New directory.
* sysdeps/mach/htl: New directory.
* sysdeps/mach/hurd/htl: New directory.
* sysdeps/mach/hurd/i386/htl: New directory.
* nscd/Depend, resolv/Depend, rt/Depend: Add htl dependency.
* sysdeps/mach/hurd/i386/Implies: Add mach/hurd/i386/htl imply.
* sysdeps/mach/hurd/i386/libpthread.abilist: New file.
I found the i386 libm-test-ulps files needed updating (probably the
sqrt changes perturbed exactly when excess precision was used by the
compiler).
* sysdeps/i386/fpu/libm-test-ulps: Update.
* sysdeps/i386/i686/fpu/multiarch/libm-test-ulps: Likewise.
This patch series cleans up the many uses of __ieee754_sqrt(f/l) in GLIBC.
The goal is to enable GCC to do the inlining, and if this fails call the
__ieee754_sqrt function. This is done by internally declaring sqrt with asm
redirects. The compat symbols and sqrt wrappers need to disable the redirect.
The redirect is also disabled if there are already redirects defined when
using -ffinite-math-only.
All math functions (but not math tests, non-library code and libnldbl) are
built with -fno-math-errno which means GCC will typically inline sqrt as a
single instruction. This means targets are no longer forced to add a special
inline for sqrt.
* include/math.h (sqrt): Declare with asm redirect.
(sqrtf): Likewise.
(sqrtl): Likewise.
(sqrtf128): Likewise.
* Makeconfig: Add -fno-math-errno for libc/libm, but build testsuite,
nonlib and libnldbl with -fmath-errno.
* math/w_sqrt_compat.c: Define NO_MATH_REDIRECT.
* math/w_sqrt_template.c: Likewise.
* math/w_sqrtf_compat.c: Likewise.
* math/w_sqrtl_compat.c: Likewise.
* sysdeps/i386/fpu/w_sqrt.c: Likewise.
* sysdeps/i386/fpu/w_sqrt_compat.c: Likewise.
* sysdeps/generic/math-type-macros-float128.h: Remove math.h and
complex.h.
As discussed in bug 22902, the i386 fenv_private.h implementation has
problems for float128 for the case of 32-bit glibc built with libgcc
from GCC configured using --with-fpmath=sse.
The optimized floating-point state handling in fenv_private.h needs to
know which floating-point state - x87 or SSE - is used for each
floating-point type, so that only one state needs updating / testing
for libm code using that state internally. On 32-bit x86, the x87
rounding mode is always used for float128, but the x87 exception flags
are only used when libgcc is built using x87 floating-point
arithmetic; if libgcc is built for SSE arithmetic, the SSE exception
flags are used.
The choice of arithmetic with which libgcc is built is independent of
that with which glibc is built. Thus, since glibc cannot tell the
choice used in libgcc, the default implementations of
libc_feholdexcept_setroundf128 and libc_feupdateenv_testf128 (which
use the <fenv.h> functions, thus using both x87 and SSE state on
processors that have both) need to be used; this patch updates the
code accordingly.
Tested for 32-bit x86; HJ reports testing in the --with-fpmath=sse
case.
[BZ #22902]
* sysdeps/i386/fpu/fenv_private.h [!__x86_64__]
(libc_feholdexcept_setroundf128): New macro.
[!__x86_64__] (libc_feupdateenv_testf128): Likewise.
Remove the slow paths from pow. Like several other double precision math
functions, pow is exactly rounded. This is not required from math functions
and causes major overheads as it requires multiple fallbacks using higher
precision arithmetic if a result is close to 0.5ULP. Ridiculous slowdowns
of up to 100000x have been reported when the highest precision path triggers.
All GLIBC math tests pass on AArch64 and x64 (with ULP of pow set to 1).
The worst case error is ~0.506ULP. A simple test over a few hundred million
values shows pow is 10% faster on average. This fixes BZ #13932.
[BZ #13932]
* sysdeps/ieee754/dbl-64/uexp.h (err_1): Remove.
* benchtests/pow-inputs: Update comment for slow path cases.
* manual/probes.texi (slowpow_p10): Delete removed probe.
(slowpow_p10): Likewise.
* math/Makefile: Remove halfulp.c and slowpow.c.
* sysdeps/aarch64/libm-test-ulps: Set ULP of pow to 1.
* sysdeps/generic/math_private.h (__exp1): Remove error argument.
(__halfulp): Remove.
(__slowpow): Remove.
* sysdeps/i386/fpu/halfulp.c: Delete file.
* sysdeps/i386/fpu/slowpow.c: Likewise.
* sysdeps/ia64/fpu/halfulp.c: Likewise.
* sysdeps/ia64/fpu/slowpow.c: Likewise.
* sysdeps/ieee754/dbl-64/e_exp.c (__exp1): Remove error argument,
improve comments and add error analysis.
* sysdeps/ieee754/dbl-64/e_pow.c (__ieee754_pow): Add error analysis.
(power1): Remove function:
(log1): Remove error argument, add error analysis.
(my_log2): Remove function.
* sysdeps/ieee754/dbl-64/halfulp.c: Delete file.
* sysdeps/ieee754/dbl-64/slowpow.c: Likewise.
* sysdeps/m68k/m680x0/fpu/halfulp.c: Likewise.
* sysdeps/m68k/m680x0/fpu/slowpow.c: Likewise.
* sysdeps/powerpc/power4/fpu/Makefile: Remove CPPFLAGS-slowpow.c.
* sysdeps/x86_64/fpu/libm-test-ulps: Set ULP of pow to 1.
* sysdeps/x86_64/fpu/multiarch/Makefile: Remove slowpow-fma.c,
slowpow-fma4.c, halfulp-fma.c, halfulp-fma4.c.
* sysdeps/x86_64/fpu/multiarch/e_pow-fma.c (__slowpow): Remove define.
* sysdeps/x86_64/fpu/multiarch/e_pow-fma4.c (__slowpow): Likewise.
* sysdeps/x86_64/fpu/multiarch/halfulp-fma.c: Delete file.
* sysdeps/x86_64/fpu/multiarch/halfulp-fma4.c: Likewise.
* sysdeps/x86_64/fpu/multiarch/slowpow-fma.c: Likewise.
* sysdeps/x86_64/fpu/multiarch/slowpow-fma4.c: Likewise.
This patch adds the narrowing add functions from TS 18661-1 to glibc's
libm: fadd, faddl, daddl, f32addf64, f32addf32x, f32xaddf64 for all
configurations; f32addf64x, f32addf128, f64addf64x, f64addf128,
f32xaddf64x, f32xaddf128, f64xaddf128 for configurations with
_Float64x and _Float128; __nldbl_daddl for ldbl-opt. As discussed for
the build infrastructure patch, tgmath.h support is deliberately
deferred, and FP_FAST_* macros are not applicable without optimized
function implementations.
Function implementations are added for all relevant pairs of formats
(including certain cases of a format and itself where more than one
type has that format). The main implementations use round-to-odd, or
a trivial computation in the case where both formats are the same or
where the wider format is IBM long double (in which case we don't
attempt to be correctly rounding). The sysdeps/ieee754/soft-fp
implementations use soft-fp, and are used automatically for
configurations without exceptions and rounding modes by virtue of
existing Implies files. As previously discussed, optimized versions
for particular architectures are possible, but not included.
i386 gets a special version of f32xaddf64 to avoid problems with
double rounding (similar to the existing fdim version), since this
function must round just once without an intermediate rounding to long
double. (No such special version is needed for any other function,
because the nontrivial functions use round-to-odd, which does the
intermediate computation with the rounding mode set to round-to-zero,
and double rounding is OK except in round-to-nearest mode, so is OK
for that intermediate round-to-zero computation.) mul and div will
need slightly different special versions for i386 (using round-to-odd
on long double instead of precision control) because of the
possibility of inexact intermediate results in the subnormal range for
double.
To reduce duplication among the different function implementations,
math-narrow.h gets macros CHECK_NARROW_ADD, NARROW_ADD_ROUND_TO_ODD
and NARROW_ADD_TRIVIAL.
In the trivial cases and for any architecture-specific optimized
implementations, the overhead of the errno setting might be
significant, but I think that's best handled through compiler built-in
functions rather than providing separate no-errno versions in glibc
(and likewise there are no __*_finite entry points for these function
provided, __*_finite effectively being no-errno versions at present in
most cases).
Tested for x86_64 and x86, with both GCC 6 and GCC 7. Tested for
mips64 (all three ABIs, both hard and soft float) and powerpc with GCC
7. Tested with build-many-glibcs.py with both GCC 6 and GCC 7.
* math/Makefile (libm-narrow-fns): Add add.
(libm-test-funcs-narrow): Likewise.
* math/Versions (GLIBC_2.28): Add narrowing add functions.
* math/bits/mathcalls-narrow.h (add): Use __MATHCALL_NARROW .
* math/gen-auto-libm-tests.c (test_functions): Add add.
* math/math-narrow.h (CHECK_NARROW_ADD): New macro.
(NARROW_ADD_ROUND_TO_ODD): Likewise.
(NARROW_ADD_TRIVIAL): Likewise.
* sysdeps/ieee754/float128/float128_private.h (__faddl): New
macro.
(__daddl): Likewise.
* sysdeps/ieee754/ldbl-opt/Makefile (libnldbl-calls): Add fadd and
dadd.
(CFLAGS-nldbl-dadd.c): New variable.
(CFLAGS-nldbl-fadd.c): Likewise.
* sysdeps/ieee754/ldbl-opt/Versions (GLIBC_2.28): Add
__nldbl_daddl.
* sysdeps/ieee754/ldbl-opt/nldbl-compat.h (__nldbl_daddl): New
prototype.
* manual/arith.texi (Misc FP Arithmetic): Document fadd, faddl,
daddl, fMaddfN, fMaddfNx, fMxaddfN and fMxaddfNx.
* math/auto-libm-test-in: Add tests of add.
* math/auto-libm-test-out-narrow-add: New generated file.
* math/libm-test-narrow-add.inc: New file.
* sysdeps/i386/fpu/s_f32xaddf64.c: Likewise.
* sysdeps/ieee754/dbl-64/s_f32xaddf64.c: Likewise.
* sysdeps/ieee754/dbl-64/s_fadd.c: Likewise.
* sysdeps/ieee754/float128/s_f32addf128.c: Likewise.
* sysdeps/ieee754/float128/s_f64addf128.c: Likewise.
* sysdeps/ieee754/float128/s_f64xaddf128.c: Likewise.
* sysdeps/ieee754/ldbl-128/s_daddl.c: Likewise.
* sysdeps/ieee754/ldbl-128/s_f64xaddf128.c: Likewise.
* sysdeps/ieee754/ldbl-128/s_faddl.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_daddl.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_faddl.c: Likewise.
* sysdeps/ieee754/ldbl-96/s_daddl.c: Likewise.
* sysdeps/ieee754/ldbl-96/s_faddl.c: Likewise.
* sysdeps/ieee754/ldbl-opt/nldbl-dadd.c: Likewise.
* sysdeps/ieee754/ldbl-opt/nldbl-fadd.c: Likewise.
* sysdeps/ieee754/soft-fp/s_daddl.c: Likewise.
* sysdeps/ieee754/soft-fp/s_fadd.c: Likewise.
* sysdeps/ieee754/soft-fp/s_faddl.c: Likewise.
* sysdeps/powerpc/fpu/libm-test-ulps: Update.
* sysdeps/mach/hurd/i386/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/aarch64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/alpha/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/arm/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/hppa/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/i386/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/ia64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/coldfire/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/m680x0/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/microblaze/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/nios2/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm-le.abilist: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/riscv/rv64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sh/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Likewise.
TS 18661-1 defines libm functions that carry out an operation (+ - * /
sqrt fma) on their arguments and return a result rounded to a
(usually) narrower type, as if the original result were computed to
infinite precision and then rounded directly to the result type
without any intermediate rounding to the argument type. For example,
fadd, faddl and daddl for addition. These are the last remaining TS
18661-1 functions left to be added to glibc. TS 18661-3 extends this
to corresponding functions for _FloatN and _FloatNx types.
As functions parametrized by two rather than one varying
floating-point types, these functions require infrastructure in glibc
that was not required for previous libm functions. This patch
provides such infrastructure - excluding test support, and actual
function implementations, which will be in subsequent patches.
Declaring the functions uses a header bits/mathcalls-narrow.h, which
is included many times, for each relevant pair of types. This will
end up containing macro calls of the form
__MATHCALL_NARROW (__MATHCALL_NAME (add), __MATHCALL_REDIR_NAME (add), 2);
for each family of narrowing functions. (The structure of this macro
call, with the calls to __MATHCALL_NAME and __MATHCALL_REDIR_NAME
there rather than in the definition of __MATHCALL_NARROW, arises from
the names such as "add" *not* themselves being reserved identifiers -
meaning it's necessary to avoid any indirection that would result in a
user-defined "add" macro being expanded.) Whereas for existing
functions declaring long double functions is disabled if _LIBC in the
case where they alias double functions, to facilitate defining the
long double functions as aliases of the double ones, there is no such
logic for the narrowing functions in this patch. Rather, the files
defining such functions are expected to use #define to hide the
original declarations of the alias names, to avoid errors about
defining aliases with incompatible types.
math/Makefile support is added for building the functions (listed in
libm-narrow-fns, currently empty) for all relevant pairs of types. An
internal header math-narrow.h is added for macros shared between
multiple function implementations - currently a ROUND_TO_ODD macro to
facilitate writing functions using the round-to-odd implementation
approach, and alias macros to create all the required function
aliases. libc_feholdexcept_setroundf128 and libc_feupdateenv_testf128
are added for use when required (only for x86_64). float128_private.h
support is added for ldbl-128 narrowing functions to be used for
_Float128.
Certain things are specifically omitted from this patch and the
immediate followups. tgmath.h support is deferred; there remain
unresolved questions about how the type-generic macros for these
functions are supposed to work, especially in the case of arguments of
integer type. The math.h / bits/mathcalls-narrow.h logic, and the
logic for determining what functions / aliases to define, will need
some adjustments to support the sqrt and fma functions, where
e.g. f32xsqrtf64 can just be an alias for sqrt rather than a separate
function. TS 18661-1 defines FP_FAST_* macros but no support is
included for defining them (they won't in general be true without
architecture-specific optimized function versions).
For each of the function groups (add sub mul div sqrt fma) there are
always six functions present (e.g. fadd, faddl, daddl, f32addf64,
f32addf32x, f32xaddf64). When _Float64x and _Float128 are supported,
there are seven more (e.g. f32addf64x, f32addf128, f64addf64x,
f64addf128, f32xaddf64x, f32xaddf128, f64xaddf128). In addition, in
the ldbl-opt case there are function names such as __nldbl_daddl (an
alias for f32xaddf64, which is not a reserved name in TS 18661-1, only
in TS 18661-3), for calls to daddl to be mapped to in the
-mlong-double-64 case. (Calls to faddl just get mapped to fadd, and
for sqrt and fma there won't be __nldbl_* functions because dsqrtl and
dfmal can just be mapped to sqrt and fma with -mlong-double-64.)
While there are six or thirteen functions present in each group (plus
__nldbl_* names only as an ABI, not an API), not all are distinct;
they fall in various groups of aliases. There are two distinct
versions built if long double has the same format as double; four if
they have distinct formats but there is no _Float64x or _Float128
support; five if long double has binary128 format; seven when
_Float128 is distinct from long double.
Architecture-specific optimized versions are possible, but not
included in my patches. For example, IA64 generally supports
narrowing the result of most floating-point instructions; Power ISA
2.07 (POWER8) supports double values as arguments to float
instructions, with the results narrowed as expected; Power ISA 3
(POWER9) supports round-to-odd for float128 instructions, so meaning
that approach can be used without needing to set and restore the
rounding mode and test "inexact". I intend to leave any such
optimized versions to the architecture maintainers. Generally in such
cases it would also make sense for calls to these functions to be
expanded inline (given -fno-math-errno); I put a suggestion for TS
18661-1 built-in functions at <https://gcc.gnu.org/wiki/SummerOfCode>.
Tested for x86_64 (this patch in isolation, as well as testing for
various configurations in conjunction with further patches).
* math/bits/mathcalls-narrow.h: New file.
* include/bits/mathcalls-narrow.h: Likewise.
* math/math-narrow.h: Likewise.
* math/math.h (__MATHCALL_NARROW_ARGS_1): New macro.
(__MATHCALL_NARROW_ARGS_2): Likewise.
(__MATHCALL_NARROW_ARGS_3): Likewise.
(__MATHCALL_NARROW_NORMAL): Likewise.
(__MATHCALL_NARROW_REDIR): Likewise.
(__MATHCALL_NARROW): Likewise.
[__GLIBC_USE (IEC_60559_BFP_EXT)]: Repeatedly include
<bits/mathcalls-narrow.h> with _Mret_, _Marg_ and __MATHCALL_NAME
defined.
[__GLIBC_USE (IEC_60559_TYPES_EXT)]: Likewise.
* math/Makefile (headers): Add bits/mathcalls-narrow.h.
(libm-narrow-fns): New variable.
(libm-narrow-types-basic): Likewise.
(libm-narrow-types-ldouble-yes): Likewise.
(libm-narrow-types-float128-yes): Likewise.
(libm-narrow-types-float128-alias-yes): Likewise.
(libm-narrow-types): Likewise.
(libm-routines): Add narrowing functions.
* sysdeps/i386/fpu/fenv_private.h [__x86_64__]
(libc_feholdexcept_setroundf128): New macro.
[__x86_64__] (libc_feupdateenv_testf128): Likewise.
* sysdeps/ieee754/float128/float128_private.h: Include
<math/math-narrow.h>.
[libc_feholdexcept_setroundf128] (libc_feholdexcept_setroundl):
Undefine and redefine.
[libc_feupdateenv_testf128] (libc_feupdateenv_testl): Likewise.
(libm_alias_float_ldouble): Undefine and redefine.
(libm_alias_double_ldouble): Likewise.
In commit cba595c350 and commit
f81ddabffd, ABI compatibility with
applications was broken by increasing the size of the on-stack
allocated __pthread_unwind_buf_t beyond the oringal size.
Applications only have the origianl space available for
__pthread_unwind_register, and __pthread_unwind_next to use,
any increase in the size of __pthread_unwind_buf_t causes these
functions to write beyond the original structure into other
on-stack variables leading to segmentation faults in common
applications like vlc. The only workaround is to version those
functions which operate on the old sized objects, but this must
happen in glibc 2.28.
Thank you to Andrew Senkevich, H.J. Lu, and Aurelien Jarno, for
submitting reports and tracking the issue down.
The commit reverts the above mentioned commits and testing on
x86_64 shows that the ABI compatibility is restored. A tst-cleanup1
regression test linked with an older glibc now passes when run
with the newly built glibc. Previously a tst-cleanup1 linked with
an older glibc would segfault when run with an affected glibc build.
Tested on x86_64 with no regressions.
Signed-off-by: Carlos O'Donell <carlos@redhat.com>
These changes will be active for all platforms that don't provide
their own exp() routines. They will also be active for ieee754
versions of ccos, ccosh, cosh, csin, csinh, sinh, exp10, gamma, and
erf.
Typical performance gains is typically around 5x when measured on
Sparc s7 for common values between exp(1) and exp(40).
Using the glibc perf tests on sparc,
sparc (nsec) x86 (nsec)
old new old new
max 17629 395 5173 144
min 399 54 15 13
mean 5317 200 1349 23
The extreme max times for the old (ieee754) exp are due to the
multiprecision computation in the old algorithm when the true value is
very near 0.5 ulp away from an value representable in double
precision. The new algorithm does not take special measures for those
cases. The current glibc exp perf tests overrepresent those values.
Informal testing suggests approximately one in 200 cases might
invoke the high cost computation. The performance advantage of the new
algorithm for other values is still large but not as large as indicated
by the chart above.
Glibc correctness tests for exp() and expf() were run. Within the
test suite 3 input values were found to cause 1 bit differences (ulp)
when "FE_TONEAREST" rounding mode is set. No differences in exp() were
seen for the tested values for the other rounding modes.
Typical example:
exp(-0x1.760cd2p+0) (-1.46113312244415283203125)
new code: 2.31973271630014299393707e-01 0x1.db14cd799387ap-3
old code: 2.31973271630014271638132e-01 0x1.db14cd7993879p-3
exp = 2.31973271630014285508337 (high precision)
Old delta: off by 0.49 ulp
New delta: off by 0.51 ulp
In addition, because ieee754_exp() is used by other routines, cexp()
showed test results with very small imaginary input values where the
imaginary portion of the result was off by 3 ulp when in upward
rounding mode, but not in the other rounding modes. For x86, tgamma
showed a few values where the ulp increased to 6 (max ulp for tgamma
is 5). Sparc tgamma did not show these failures. I presume the tgamma
differences are due to compiler optimization differences within the
gamma function.The gamma function is known to be difficult to compute
accurately.
* sysdeps/ieee754/dbl-64/e_exp.c: Include <math-svid-compat.h> and
<errno.h>. Include "eexp.tbl".
(half): New constant.
(one): Likewise.
(__ieee754_exp): Rewrite.
(__slowexp): Remove prototype.
* sysdeps/ieee754/dbl-64/eexp.tbl: New file.
* sysdeps/ieee754/dbl-64/slowexp.c: Remove file.
* sysdeps/i386/fpu/slowexp.c: Likewise.
* sysdeps/ia64/fpu/slowexp.c: Likewise.
* sysdeps/m68k/m680x0/fpu/slowexp.c: Likewise.
* sysdeps/x86_64/fpu/multiarch/slowexp-avx.c: Likewise.
* sysdeps/x86_64/fpu/multiarch/slowexp-fma.c: Likewise.
* sysdeps/x86_64/fpu/multiarch/slowexp-fma4.c: Likewise.
* sysdeps/generic/math_private.h (__slowexp): Remove prototype.
* sysdeps/ieee754/dbl-64/e_pow.c: Remove mention of slowexp.c in
comment.
* sysdeps/powerpc/power4/fpu/Makefile [$(subdir) = math]
(CPPFLAGS-slowexp.c): Remove variable.
* sysdeps/x86_64/fpu/multiarch/Makefile (libm-sysdep_routines):
Remove slowexp-fma, slowexp-fma4 and slowexp-avx.
(CFLAGS-slowexp-fma.c): Remove variable.
(CFLAGS-slowexp-fma4.c): Likewise.
(CFLAGS-slowexp-avx.c): Likewise.
* sysdeps/x86_64/fpu/multiarch/e_exp-avx.c (__slowexp): Do not
define as macro.
* sysdeps/x86_64/fpu/multiarch/e_exp-fma.c (__slowexp): Likewise.
* sysdeps/x86_64/fpu/multiarch/e_exp-fma4.c (__slowexp): Likewise.
* math/Makefile (type-double-routines): Remove slowexp.
* manual/probes.texi (slowexp_p6): Remove.
(slowexp_p32): Likewise.
On x86, padding in struct __jmp_buf_tag is used for shadow stack pointer
to support Shadow Stack in Intel Control-flow Enforcemen Technology.
cancel_jmp_buf has been updated to include saved_mask so that it is as
large as struct __jmp_buf_tag. We must suport the old cancel_jmp_buf
in existing binaries. Since symbol versioning doesn't work on
cancel_jmp_buf, feature_1 is added to tcbhead_t so that setjmp and
longjmp can check if shadow stack is enabled. NB: Shadow stack is
enabled only if all modules are shadow stack enabled.
[BZ #22563]
* sysdeps/i386/nptl/tcb-offsets.sym (FEATURE_1_OFFSET): New.
* sysdeps/i386/nptl/tls.h (tcbhead_t): Add feature_1.
* sysdeps/x86_64/nptl/tcb-offsets.sym (FEATURE_1_OFFSET): New.
* sysdeps/x86_64/nptl/tls.h (tcbhead_t): Rename __glibc_unused1
to feature_1.
Static PIE extends address space layout randomization to static
executables. It provides additional security hardening benefits at
the cost of some memory and performance.
Dynamic linker, ld.so, is a standalone program which can be loaded at
any address. This patch adds a configure option, --enable-static-pie,
to embed the part of ld.so in static executable to create static position
independent executable (static PIE). A static PIE is similar to static
executable, but can be loaded at any address without help from a dynamic
linker. When --enable-static-pie is used to configure glibc, libc.a is
built as PIE and all static executables, including tests, are built as
static PIE. The resulting libc.a can be used together with GCC 8 or
above to build static PIE with the compiler option, -static-pie. But
GCC 8 isn't required to build glibc with --enable-static-pie. Only GCC
with PIE support is needed. When an older GCC is used to build glibc
with --enable-static-pie, proper input files are passed to linker to
create static executables as static PIE, together with "-z text" to
prevent dynamic relocations in read-only segments, which are not allowed
in static PIE.
The following changes are made for static PIE:
1. Add a new function, _dl_relocate_static_pie, to:
a. Get the run-time load address.
b. Read the dynamic section.
c. Perform dynamic relocations.
Dynamic linker also performs these steps. But static PIE doesn't load
any shared objects.
2. Call _dl_relocate_static_pie at entrance of LIBC_START_MAIN in
libc.a. crt1.o, which is used to create dynamic and non-PIE static
executables, is updated to include a dummy _dl_relocate_static_pie.
rcrt1.o is added to create static PIE, which will link in the real
_dl_relocate_static_pie. grcrt1.o is also added to create static PIE
with -pg. GCC 8 has been updated to support rcrt1.o and grcrt1.o for
static PIE.
Static PIE can work on all architectures which support PIE, provided:
1. Target must support accessing of local functions without dynamic
relocations, which is needed in start.S to call __libc_start_main with
function addresses of __libc_csu_init, __libc_csu_fini and main. All
functions in static PIE are local functions. If PIE start.S can't reach
main () defined in a shared object, the code sequence:
pass address of local_main to __libc_start_main
...
local_main:
tail call to main via PLT
can be used.
2. start.S is updated to check PIC instead SHARED for PIC code path and
avoid dynamic relocation, when PIC is defined and SHARED isn't defined,
to support static PIE.
3. All assembly codes are updated check PIC instead SHARED for PIC code
path to avoid dynamic relocations in read-only sections.
4. All assembly codes are updated check SHARED instead PIC for static
symbol name.
5. elf_machine_load_address in dl-machine.h are updated to support static
PIE.
6. __brk works without TLS nor dynamic relocations in read-only section
so that it can be used by __libc_setup_tls to initializes TLS in static
PIE.
NB: When glibc is built with GCC defaulted to PIE, libc.a is compiled
with -fPIE, regardless if --enable-static-pie is used to configure glibc.
When glibc is configured with --enable-static-pie, libc.a is compiled
with -fPIE, regardless whether GCC defaults to PIE or not. The same
libc.a can be used to build both static executable and static PIE.
There is no need for separate PIE copy of libc.a.
On x86-64, the normal static sln:
text data bss dec hex filename
625425 8284 5456 639165 9c0bd elf/sln
the static PIE sln:
text data bss dec hex filename
657626 20636 5392 683654 a6e86 elf/sln
The code size is increased by 5% and the binary size is increased by 7%.
Linker requirements to build glibc with --enable-static-pie:
1. Linker supports --no-dynamic-linker to remove PT_INTERP segment from
static PIE.
2. Linker can create working static PIE. The x86-64 linker needs the
fix for
https://sourceware.org/bugzilla/show_bug.cgi?id=21782
The i386 linker needs to be able to convert "movl main@GOT(%ebx), %eax"
to "leal main@GOTOFF(%ebx), %eax" if main is defined locally.
Binutils 2.29 or above are OK for i686 and x86-64. But linker status for
other targets need to be verified.
3. Linker should resolve undefined weak symbols to 0 in static PIE:
https://sourceware.org/bugzilla/show_bug.cgi?id=22269
4. Many ELF backend linkers incorrectly check bfd_link_pic for TLS
relocations, which should check bfd_link_executable instead:
https://sourceware.org/bugzilla/show_bug.cgi?id=22263
Tested on aarch64, i686 and x86-64.
Using GCC 7 and binutils master branch, build-many-glibcs.py with
--enable-static-pie with all patches for static PIE applied have the
following build successes:
PASS: glibcs-aarch64_be-linux-gnu build
PASS: glibcs-aarch64-linux-gnu build
PASS: glibcs-armeb-linux-gnueabi-be8 build
PASS: glibcs-armeb-linux-gnueabi build
PASS: glibcs-armeb-linux-gnueabihf-be8 build
PASS: glibcs-armeb-linux-gnueabihf build
PASS: glibcs-arm-linux-gnueabi build
PASS: glibcs-arm-linux-gnueabihf build
PASS: glibcs-arm-linux-gnueabihf-v7a build
PASS: glibcs-arm-linux-gnueabihf-v7a-disable-multi-arch build
PASS: glibcs-m68k-linux-gnu build
PASS: glibcs-microblazeel-linux-gnu build
PASS: glibcs-microblaze-linux-gnu build
PASS: glibcs-mips64el-linux-gnu-n32 build
PASS: glibcs-mips64el-linux-gnu-n32-nan2008 build
PASS: glibcs-mips64el-linux-gnu-n32-nan2008-soft build
PASS: glibcs-mips64el-linux-gnu-n32-soft build
PASS: glibcs-mips64el-linux-gnu-n64 build
PASS: glibcs-mips64el-linux-gnu-n64-nan2008 build
PASS: glibcs-mips64el-linux-gnu-n64-nan2008-soft build
PASS: glibcs-mips64el-linux-gnu-n64-soft build
PASS: glibcs-mips64-linux-gnu-n32 build
PASS: glibcs-mips64-linux-gnu-n32-nan2008 build
PASS: glibcs-mips64-linux-gnu-n32-nan2008-soft build
PASS: glibcs-mips64-linux-gnu-n32-soft build
PASS: glibcs-mips64-linux-gnu-n64 build
PASS: glibcs-mips64-linux-gnu-n64-nan2008 build
PASS: glibcs-mips64-linux-gnu-n64-nan2008-soft build
PASS: glibcs-mips64-linux-gnu-n64-soft build
PASS: glibcs-mipsel-linux-gnu build
PASS: glibcs-mipsel-linux-gnu-nan2008 build
PASS: glibcs-mipsel-linux-gnu-nan2008-soft build
PASS: glibcs-mipsel-linux-gnu-soft build
PASS: glibcs-mips-linux-gnu build
PASS: glibcs-mips-linux-gnu-nan2008 build
PASS: glibcs-mips-linux-gnu-nan2008-soft build
PASS: glibcs-mips-linux-gnu-soft build
PASS: glibcs-nios2-linux-gnu build
PASS: glibcs-powerpc64le-linux-gnu build
PASS: glibcs-powerpc64-linux-gnu build
PASS: glibcs-tilegxbe-linux-gnu-32 build
PASS: glibcs-tilegxbe-linux-gnu build
PASS: glibcs-tilegx-linux-gnu-32 build
PASS: glibcs-tilegx-linux-gnu build
PASS: glibcs-tilepro-linux-gnu build
and the following build failures:
FAIL: glibcs-alpha-linux-gnu build
elf/sln is failed to link due to:
assertion fail bfd/elf64-alpha.c:4125
This is caused by linker bug and/or non-PIC code in PIE libc.a.
FAIL: glibcs-hppa-linux-gnu build
elf/sln is failed to link due to:
collect2: fatal error: ld terminated with signal 11 [Segmentation fault]
https://sourceware.org/bugzilla/show_bug.cgi?id=22537
FAIL: glibcs-ia64-linux-gnu build
elf/sln is failed to link due to:
collect2: fatal error: ld terminated with signal 11 [Segmentation fault]
FAIL: glibcs-powerpc-linux-gnu build
FAIL: glibcs-powerpc-linux-gnu-soft build
FAIL: glibcs-powerpc-linux-gnuspe build
FAIL: glibcs-powerpc-linux-gnuspe-e500v1 build
elf/sln is failed to link due to:
ld: read-only segment has dynamic relocations.
This is caused by linker bug and/or non-PIC code in PIE libc.a. See:
https://sourceware.org/bugzilla/show_bug.cgi?id=22264
FAIL: glibcs-powerpc-linux-gnu-power4 build
elf/sln is failed to link due to:
findlocale.c:96:(.text+0x22c): @local call to ifunc memchr
This is caused by linker bug and/or non-PIC code in PIE libc.a.
FAIL: glibcs-s390-linux-gnu build
elf/sln is failed to link due to:
collect2: fatal error: ld terminated with signal 11 [Segmentation fault], core dumped
assertion fail bfd/elflink.c:14299
This is caused by linker bug and/or non-PIC code in PIE libc.a.
FAIL: glibcs-sh3eb-linux-gnu build
FAIL: glibcs-sh3-linux-gnu build
FAIL: glibcs-sh4eb-linux-gnu build
FAIL: glibcs-sh4eb-linux-gnu-soft build
FAIL: glibcs-sh4-linux-gnu build
FAIL: glibcs-sh4-linux-gnu-soft build
elf/sln is failed to link due to:
ld: read-only segment has dynamic relocations.
This is caused by linker bug and/or non-PIC code in PIE libc.a. See:
https://sourceware.org/bugzilla/show_bug.cgi?id=22263
Also TLS code sequence in SH assembly syscalls in glibc doesn't match TLS
code sequence expected by ld:
https://sourceware.org/bugzilla/show_bug.cgi?id=22270
FAIL: glibcs-sparc64-linux-gnu build
FAIL: glibcs-sparcv9-linux-gnu build
FAIL: glibcs-tilegxbe-linux-gnu build
FAIL: glibcs-tilegxbe-linux-gnu-32 build
FAIL: glibcs-tilegx-linux-gnu build
FAIL: glibcs-tilegx-linux-gnu-32 build
FAIL: glibcs-tilepro-linux-gnu build
elf/sln is failed to link due to:
ld: read-only segment has dynamic relocations.
This is caused by linker bug and/or non-PIC code in PIE libc.a. See:
https://sourceware.org/bugzilla/show_bug.cgi?id=22263
[BZ #19574]
* INSTALL: Regenerated.
* Makeconfig (real-static-start-installed-name): New.
(pic-default): Updated for --enable-static-pie.
(pie-default): New for --enable-static-pie.
(default-pie-ldflag): Likewise.
(+link-static-before-libc): Replace $(DEFAULT-LDFLAGS-$(@F))
with $(if $($(@F)-no-pie),$(no-pie-ldflag),$(default-pie-ldflag)).
Replace $(static-start-installed-name) with
$(real-static-start-installed-name).
(+prectorT): Updated for --enable-static-pie.
(+postctorT): Likewise.
(CFLAGS-.o): Add $(pie-default).
(CFLAGS-.op): Likewise.
* NEWS: Mention --enable-static-pie.
* config.h.in (ENABLE_STATIC_PIE): New.
* configure.ac (--enable-static-pie): New configure option.
(have-no-dynamic-linker): New LIBC_CONFIG_VAR.
(have-static-pie): Likewise.
Enable static PIE if linker supports --no-dynamic-linker.
(ENABLE_STATIC_PIE): New AC_DEFINE.
(enable-static-pie): New LIBC_CONFIG_VAR.
* configure: Regenerated.
* csu/Makefile (omit-deps): Add r$(start-installed-name) and
gr$(start-installed-name) for --enable-static-pie.
(extra-objs): Likewise.
(install-lib): Likewise.
(extra-objs): Add static-reloc.o and static-reloc.os
($(objpfx)$(start-installed-name)): Also depend on
$(objpfx)static-reloc.o.
($(objpfx)r$(start-installed-name)): New.
($(objpfx)g$(start-installed-name)): Also depend on
$(objpfx)static-reloc.os.
($(objpfx)gr$(start-installed-name)): New.
* csu/libc-start.c (LIBC_START_MAIN): Call _dl_relocate_static_pie
in libc.a.
* csu/libc-tls.c (__libc_setup_tls): Add main_map->l_addr to
initimage.
* csu/static-reloc.c: New file.
* elf/Makefile (routines): Add dl-reloc-static-pie.
(elide-routines.os): Likewise.
(DEFAULT-LDFLAGS-tst-tls1-static-non-pie): Removed.
(tst-tls1-static-non-pie-no-pie): New.
* elf/dl-reloc-static-pie.c: New file.
* elf/dl-support.c (_dl_get_dl_main_map): New function.
* elf/dynamic-link.h (ELF_DURING_STARTUP): Also check
STATIC_PIE_BOOTSTRAP.
* elf/get-dynamic-info.h (elf_get_dynamic_info): Likewise.
* gmon/Makefile (tests): Add tst-gmon-static-pie.
(tests-static): Likewise.
(DEFAULT-LDFLAGS-tst-gmon-static): Removed.
(tst-gmon-static-no-pie): New.
(CFLAGS-tst-gmon-static-pie.c): Likewise.
(CRT-tst-gmon-static-pie): Likewise.
(tst-gmon-static-pie-ENV): Likewise.
(tests-special): Likewise.
($(objpfx)tst-gmon-static-pie.out): Likewise.
(clean-tst-gmon-static-pie-data): Likewise.
($(objpfx)tst-gmon-static-pie-gprof.out): Likewise.
* gmon/tst-gmon-static-pie.c: New file.
* manual/install.texi: Document --enable-static-pie.
* sysdeps/generic/ldsodefs.h (_dl_relocate_static_pie): New.
(_dl_get_dl_main_map): Likewise.
* sysdeps/i386/configure.ac: Check if linker supports static PIE.
* sysdeps/x86_64/configure.ac: Likewise.
* sysdeps/i386/configure: Regenerated.
* sysdeps/x86_64/configure: Likewise.
* sysdeps/mips/Makefile (ASFLAGS-.o): Add $(pie-default).
(ASFLAGS-.op): Likewise.
This patch continues filling out TS 18661-3 support by adding *f64 and
*f32x function aliases, supporting _Float64 and _Float32x, as aliases
for double functions. These types are supported for all glibc
configurations. The API corresponds exactly to that for _Float128 and
_Float64x. _Float32 aliases to float functions remain to be added in
subsequent patches to complete this process (then there are a few
miscellaneous functions in TS 18661-3 to implement that aren't simply
versions of existing functions for new types).
The patch enables the feature in bits/floatn-common.h, adds symbol
versions and documentation with updates to ABI baselines, and arranges
for the libm functions for the new types to be tested. As with the
_Float64x changes there are some x86 ulps updates because of header
inlines not used for the new types (and one other change to the
non-multiarch libm-test-ulps, which I suppose comes from using a
different compiler version / configuration from when it was last
regenerated).
Tested for x86_64 and x86, and with build-many-glibcs.py, with both
GCC 6 and GCC 7.
* bits/floatn-common.h (__HAVE_FLOAT64): Define to 1.
(__HAVE_FLOAT32X): Likewise.
* manual/math.texi (Mathematics): Document support for _Float64
and _Float32x.
* math/Makefile (test-types): Add float64 and float32x.
* math/Versions (GLIBC_2.27): Add _Float64 and _Float32x
functions.
* stdlib/Versions (GLIBC_2.27): Likewise.
* wcsmbs/Versions (GLIBC_2.27): Likewise.
* sysdeps/unix/sysv/linux/aarch64/libc.abilist: Update.
* sysdeps/unix/sysv/linux/aarch64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/alpha/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/alpha/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/arm/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/arm/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/hppa/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/hppa/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/i386/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/i386/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/ia64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/ia64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/coldfire/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/m680x0/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/microblaze/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/microblaze/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist:
Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/nios2/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/nios2/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm-le.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sh/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/sh/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist:
Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist:
Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/tile/tilepro/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Likewise.
* sysdeps/i386/fpu/libm-test-ulps: Likewise.
* sysdeps/i386/i686/fpu/multiarch/libm-test-ulps: Likewise.
Continuing the preparation for additional _FloatN / _FloatNx function
aliases, this patch makes i386 libm function implementations use
libm_alias_float (or libm_alias_float_other in cases where the main
symbol name is defined with versioned_symbol) to define function
aliases.
Tested with build-many-glibcs.py for all its i386 configurations that
installed stripped shared libraries are unchanged by the patch, as
well as running the full glibc testsuite for i686.
* sysdeps/i386/fpu/s_asinhf.S: Include <libm-alias-float.h>.
(asinhf): Define using libm_alias_float.
* sysdeps/i386/fpu/s_atanf.S: Include <libm-alias-float.h>.
(atanf): Define using libm_alias_float.
* sysdeps/i386/fpu/s_cbrtf.S: Include <libm-alias-float.h>.
(cbrtf): Define using libm_alias_float.
* sysdeps/i386/fpu/s_ceilf.S: Include <libm-alias-float.h>.
(ceilf): Define using libm_alias_float.
* sysdeps/i386/fpu/s_copysignf.S: Include <libm-alias-float.h>.
(copysignf): Define using libm_alias_float.
* sysdeps/i386/fpu/s_expm1f.S: Include <libm-alias-float.h>.
(expm1f): Define using libm_alias_float.
* sysdeps/i386/fpu/s_fabsf.S: Include <libm-alias-float.h>.
(fabsf): Define using libm_alias_float.
* sysdeps/i386/fpu/s_floorf.S: Include <libm-alias-float.h>.
(floorf): Define using libm_alias_float.
* sysdeps/i386/fpu/s_fmaxf.S: Include <libm-alias-float.h>.
(fmaxf): Define using libm_alias_float.
* sysdeps/i386/fpu/s_fminf.S: Include <libm-alias-float.h>.
(fminf): Define using libm_alias_float.
* sysdeps/i386/fpu/s_frexpf.S: Include <libm-alias-float.h>.
(frexpf): Define using libm_alias_float.
* sysdeps/i386/fpu/s_llrintf.S: Include <libm-alias-float.h>.
(llrintf): Define using libm_alias_float.
* sysdeps/i386/fpu/s_logbf.S: Include <libm-alias-float.h>.
(logbf): Define using libm_alias_float.
* sysdeps/i386/fpu/s_lrintf.S: Include <libm-alias-float.h>.
(lrintf): Define using libm_alias_float.
* sysdeps/i386/fpu/s_nearbyintf.S: Include <libm-alias-float.h>.
(nearbyintf): Define using libm_alias_float.
* sysdeps/i386/fpu/s_remquof.S: Include <libm-alias-float.h>.
(remquof): Define using libm_alias_float.
* sysdeps/i386/fpu/s_rintf.S: Include <libm-alias-float.h>.
(rintf): Define using libm_alias_float.
* sysdeps/i386/fpu/s_truncf.S: Include <libm-alias-float.h>.
(truncf): Define using libm_alias_float.
* sysdeps/i386/i686/fpu/multiarch/e_exp2f.c: Include
<libm-alias-float.h>.
(exp2f): Define using libm_alias_float, or libm_alias_float_other
if [SHARED].
* sysdeps/i386/i686/fpu/multiarch/e_expf.c: Include
<libm-alias-float.h>.
(expf): Define using libm_alias_float, or libm_alias_float_other
if [SHARED].
* sysdeps/i386/i686/fpu/multiarch/e_log2f.c: Include
<libm-alias-float.h>.
(log2f): Define using libm_alias_float, or libm_alias_float_other
if [SHARED].
* sysdeps/i386/i686/fpu/multiarch/e_logf.c: Include
<libm-alias-float.h>.
(logf): Define using libm_alias_float, or libm_alias_float_other
if [SHARED].
* sysdeps/i386/i686/fpu/multiarch/e_powf.c: Include
<libm-alias-float.h>.
(powf): Define using libm_alias_float, or libm_alias_float_other
if [SHARED].
* sysdeps/i386/i686/fpu/multiarch/s_cosf.c: Include
<libm-alias-float.h>.
(cosf): Define using libm_alias_float.
* sysdeps/i386/i686/fpu/multiarch/s_sincosf.c: Include
<libm-alias-float.h>.
(sincosf): Define using libm_alias_float.
* sysdeps/i386/i686/fpu/multiarch/s_sinf.c: Include
<libm-alias-float.h>.
(sinf): Define using libm_alias_float.
* sysdeps/i386/i686/fpu/s_fmaxf.S: Include <libm-alias-float.h>.
(fmaxf): Define using libm_alias_float.
* sysdeps/i386/i686/fpu/s_fminf.S: Include <libm-alias-float.h>.
(fminf): Define using libm_alias_float.
* sysdeps/i386/i686/multiarch/s_fmaf.c: Include
<libm-alias-float.h>.
(fmaf): Define using libm_alias_float.
Continuing the preparation for additional _FloatN / _FloatNx function
aliases, this patch makes i386 libm function implementations use
libm_alias_double to define function aliases.
Tested with build-many-glibcs.py for all its i386 configurations that
installed stripped shared libraries are unchanged by the patch, as
well as running the full glibc testsuite for i686.
* sysdeps/i386/fpu/s_asinh.S: Include <libm-alias-double.h>.
(asinh): Define using libm_alias_double.
* sysdeps/i386/fpu/s_atan.S: Include <libm-alias-double.h>.
(atan): Define using libm_alias_double.
* sysdeps/i386/fpu/s_cbrt.S: Include <libm-alias-double.h>.
(cbrt): Define using libm_alias_double.
* sysdeps/i386/fpu/s_ceil.S: Include <libm-alias-double.h>.
(ceil): Define using libm_alias_double.
* sysdeps/i386/fpu/s_copysign.S: Include <libm-alias-double.h>.
(copysign): Define using libm_alias_double.
* sysdeps/i386/fpu/s_expm1.S: Include <libm-alias-double.h>.
(expm1): Define using libm_alias_double.
* sysdeps/i386/fpu/s_fabs.S: Include <libm-alias-double.h>.
(fabs): Define using libm_alias_double.
* sysdeps/i386/fpu/s_fdim.c: Include <libm-alias-double.h>.
(fdim): Define using libm_alias_double.
* sysdeps/i386/fpu/s_floor.S: Include <libm-alias-double.h>.
(floor): Define using libm_alias_double.
* sysdeps/i386/fpu/s_fmax.S: Include <libm-alias-double.h>.
(fmax): Define using libm_alias_double.
* sysdeps/i386/fpu/s_fmin.S: Include <libm-alias-double.h>.
(fmin): Define using libm_alias_double.
* sysdeps/i386/fpu/s_frexp.S: Include <libm-alias-double.h>.
(frexp): Define using libm_alias_double.
* sysdeps/i386/fpu/s_llrint.S: Include <libm-alias-double.h>.
(llrint): Define using libm_alias_double.
* sysdeps/i386/fpu/s_logb.S: Include <libm-alias-double.h>.
(logb): Define using libm_alias_double.
* sysdeps/i386/fpu/s_lrint.S: Include <libm-alias-double.h>.
(lrint): Define using libm_alias_double.
* sysdeps/i386/fpu/s_nearbyint.S: Include <libm-alias-double.h>.
(nearbyint): Define using libm_alias_double.
* sysdeps/i386/fpu/s_remquo.S: Include <libm-alias-double.h>.
(remquo): Define using libm_alias_double.
* sysdeps/i386/fpu/s_rint.S: Include <libm-alias-double.h>.
(rint): Define using libm_alias_double.
* sysdeps/i386/fpu/s_trunc.S: Include <libm-alias-double.h>.
(trunc): Define using libm_alias_double.
* sysdeps/i386/i686/fpu/s_fmax.S: Include <libm-alias-double.h>.
(fmax): Define using libm_alias_double.
* sysdeps/i386/i686/fpu/s_fmin.S: Include <libm-alias-double.h>.
(fmin): Define using libm_alias_double.
* sysdeps/i386/i686/multiarch/s_fma.c: Include <libm-alias-double.h>.
(fma): Define using libm_alias_double.
This patch continues filling out TS 18661-3 support by adding *f64x
function aliases on platforms with _Float64x support. (It so happens
the set of such platforms is exactly the same as the set of platforms
with _Float128 support, although on x86_64, x86 and ia32 the _Float64x
format is Intel extended rather than binary128.) The API provided
corresponds exactly to that provided for _Float128, mostly coming from
TS 18661-3. As these functions always alias those for another type
(long double, _Float128 or both), __* function names are not provided,
as in other cases of alias types.
Given the preparation done in previous patches, this one just enables
the feature via Makeconfig and bits/floatn.h, adds symbol versions,
and updates documentation and ABI baselines. The symbol versions are
present unconditionally as GLIBC_2.27 in the relevant Versions files,
as it's OK for those to specify versions for functions that may not be
present in some configurations; no additional complexity is needed
unless in future some configuration gains support for this type that
didn't have such support in 2.27. The Makeconfig additions for ia64
and x86 aren't strictly needed, as those configurations also get
float64x-alias-fcts definitions from
sysdeps/ieee754/float128/Makeconfig, but still seem appropriate given
that _Float64x is not _Float128 for those configurations.
A libm-test-ulps update for x86 is included. This is because
bits/mathinline.h does not have _Float64x support added and for two
functions the use of out-of-line functions results in increased ulps
(ifloat64x shares ulps with ildouble / ifloat128 as appropriate).
Given that we'd like generally to eliminate bits/mathinline.h
optimizations, preferring to have such optimizations in GCC instead,
it seems reasonable not to add such support there for new types. GCC
support for _FloatN / _FloatNx built-in functions is limited, but has
been improved in GCC 8, and at some point I hope the full set of libm
built-in functions in GCC, and other optimizations with
per-floating-type aspects, will be enabled for all _FloatN / _FloatNx
types.
Tested for x86_64 and x86, and with build-many-glibcs.py, with both
GCC 6 and GCC 7.
* sysdeps/ia64/Makeconfig (float64x-alias-fcts): New variable.
* sysdeps/ieee754/float128/Makeconfig (float64x-alias-fcts):
Likewise.
* sysdeps/ieee754/ldbl-128/Makeconfig (float64x-alias-fcts):
Likewise.
* sysdeps/x86/Makeconfig: New file.
* bits/floatn-common.h (__HAVE_FLOAT64X): Remove macro.
(__HAVE_FLOAT64X_LONG_DOUBLE): Likewise.
* bits/floatn.h (__HAVE_FLOAT64X): New macro.
(__HAVE_FLOAT64X_LONG_DOUBLE): Likewise.
* sysdeps/ia64/bits/floatn.h (__HAVE_FLOAT64X): Likewise.
(__HAVE_FLOAT64X_LONG_DOUBLE): Likewise.
* sysdeps/ieee754/ldbl-128/bits/floatn.h (__HAVE_FLOAT64X):
Likewise.
(__HAVE_FLOAT64X_LONG_DOUBLE): Likewise.
* sysdeps/mips/ieee754/bits/floatn.h (__HAVE_FLOAT64X): Likewise.
(__HAVE_FLOAT64X_LONG_DOUBLE): Likewise.
* sysdeps/powerpc/bits/floatn.h (__HAVE_FLOAT64X): Likewise.
(__HAVE_FLOAT64X_LONG_DOUBLE): Likewise.
* sysdeps/x86/bits/floatn.h (__HAVE_FLOAT64X): Likewise.
(__HAVE_FLOAT64X_LONG_DOUBLE): Likewise.
* manual/math.texi (Mathematics): Document support for _Float64x.
* math/Versions (GLIBC_2.27): Add _Float64x functions.
* stdlib/Versions (GLIBC_2.27): Likewise.
* wcsmbs/Versions (GLIBC_2.27): Likewise.
* sysdeps/unix/sysv/linux/aarch64/libc.abilist: Update.
* sysdeps/unix/sysv/linux/aarch64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/alpha/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/alpha/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/i386/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/i386/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/ia64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/ia64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm-le.abilist:
Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Likewise.
* sysdeps/i386/fpu/libm-test-ulps: Likewise.
* sysdeps/i386/i686/fpu/multiarch/libm-test-ulps: Likewise.
This patch continues the preparation for additional _FloatN / _FloatNx
function aliases by using libm_alias_ldouble for sysdeps/i386/fpu long
double functions, so that they can have _Float64x aliases added in
future.
Tested for x86_64 (which includes some of these implementations) and
x86, including build-many-glibcs.py tests that installed stripped
shared libraries are unchanged by the patch.
* sysdeps/i386/fpu/e_expl.S: Include <libm-alias-ldouble.h>.
[USE_AS_EXPM1L] (expm1l): Define using libm_alias_ldouble.
* sysdeps/i386/fpu/s_asinhl.S: Include <libm-alias-ldouble.h>.
(asinhl): Define using libm_alias_ldouble.
* sysdeps/i386/fpu/s_atanl.c: Include <libm-alias-ldouble.h>.
(atanl): Define using libm_alias_ldouble.
* sysdeps/i386/fpu/s_cbrtl.S: Include <libm-alias-ldouble.h>.
(cbrtl): Define using libm_alias_ldouble.
* sysdeps/i386/fpu/s_ceill.S: Include <libm-alias-ldouble.h>.
(ceill): Define using libm_alias_ldouble.
* sysdeps/i386/fpu/s_copysignl.S: Include <libm-alias-ldouble.h>.
(copysignl): Define using libm_alias_ldouble.
* sysdeps/i386/fpu/s_fabsl.S: Include <libm-alias-ldouble.h>.
(fabsl): Define using libm_alias_ldouble.
* sysdeps/i386/fpu/s_floorl.S: Include <libm-alias-ldouble.h>.
(floorl): Define using libm_alias_ldouble.
* sysdeps/i386/fpu/s_fmaxl.S: Include <libm-alias-ldouble.h>.
(fmaxl): Define using libm_alias_ldouble.
* sysdeps/i386/fpu/s_fminl.S: Include <libm-alias-ldouble.h>.
(fminl): Define using libm_alias_ldouble.
* sysdeps/i386/fpu/s_frexpl.S: Include <libm-alias-ldouble.h>.
(frexpl): Define using libm_alias_ldouble.
* sysdeps/i386/fpu/s_llrintl.S: Include <libm-alias-ldouble.h>.
(llrintl): Define using libm_alias_ldouble.
* sysdeps/i386/fpu/s_logbl.c: Include <libm-alias-ldouble.h>.
(logbl): Define using libm_alias_ldouble.
* sysdeps/i386/fpu/s_lrintl.S: Include <libm-alias-ldouble.h>.
(lrintl): Define using libm_alias_ldouble.
* sysdeps/i386/fpu/s_nearbyintl.S: Include <libm-alias-ldouble.h>.
(nearbyintl): Define using libm_alias_ldouble.
* sysdeps/i386/fpu/s_nextafterl.c: Include <libm-alias-ldouble.h>.
(nextafterl): Define using libm_alias_ldouble.
* sysdeps/i386/fpu/s_remquol.S: Include <libm-alias-ldouble.h>.
(remquol): Define using libm_alias_ldouble.
* sysdeps/i386/fpu/s_rintl.c: Include <libm-alias-ldouble.h>.
(rintl): Define using libm_alias_ldouble.
* sysdeps/i386/fpu/s_truncl.S: Include <libm-alias-ldouble.h>.
(truncl): Define using libm_alias_ldouble.
* sysdeps/i386/i686/fpu/s_fmaxl.S: Include <libm-alias-ldouble.h>.
(fmaxl): Define using libm_alias_ldouble.
* sysdeps/i386/i686/fpu/s_fminl.S: Include <libm-alias-ldouble.h>.
(fminl): Define using libm_alias_ldouble.
This patch adds a new build test to check for internal fields
offsets for user visible internal field. Although currently
the only field which is statically initialized to a non zero value
is pthread_mutex_t.__data.__kind value, the tests also check the
offset of __kind, __spins, __elision (if supported), and __list
internal member. A internal header (pthread-offset.h) is added
to each major ABI with the reference value.
Checked on x86_64-linux-gnu and with a build check for all affected
ABIs (aarch64-linux-gnu, alpha-linux-gnu, arm-linux-gnueabihf,
hppa-linux-gnu, i686-linux-gnu, ia64-linux-gnu, m68k-linux-gnu,
microblaze-linux-gnu, mips64-linux-gnu, mips64-n32-linux-gnu,
mips-linux-gnu, powerpc64le-linux-gnu, powerpc-linux-gnu,
s390-linux-gnu, s390x-linux-gnu, sh4-linux-gnu, sparc64-linux-gnu,
sparcv9-linux-gnu, tilegx-linux-gnu, tilegx-linux-gnu-x32,
tilepro-linux-gnu, x86_64-linux-gnu, and x86_64-linux-x32).
* nptl/pthreadP.h (ASSERT_PTHREAD_STRING,
ASSERT_PTHREAD_INTERNAL_OFFSET): New macro.
* nptl/pthread_mutex_init.c (__pthread_mutex_init): Add build time
checks for internal pthread_mutex_t offsets.
* sysdeps/aarch64/nptl/pthread-offsets.h
(__PTHREAD_MUTEX_NUSERS_OFFSET, __PTHREAD_MUTEX_KIND_OFFSET,
__PTHREAD_MUTEX_SPINS_OFFSET, __PTHREAD_MUTEX_ELISION_OFFSET,
__PTHREAD_MUTEX_LIST_OFFSET): New macro.
* sysdeps/alpha/nptl/pthread-offsets.h: Likewise.
* sysdeps/arm/nptl/pthread-offsets.h: Likewise.
* sysdeps/hppa/nptl/pthread-offsets.h: Likewise.
* sysdeps/i386/nptl/pthread-offsets.h: Likewise.
* sysdeps/ia64/nptl/pthread-offsets.h: Likewise.
* sysdeps/m68k/nptl/pthread-offsets.h: Likewise.
* sysdeps/microblaze/nptl/pthread-offsets.h: Likewise.
* sysdeps/mips/nptl/pthread-offsets.h: Likewise.
* sysdeps/nios2/nptl/pthread-offsets.h: Likewise.
* sysdeps/powerpc/nptl/pthread-offsets.h: Likewise.
* sysdeps/s390/nptl/pthread-offsets.h: Likewise.
* sysdeps/sh/nptl/pthread-offsets.h: Likewise.
* sysdeps/sparc/nptl/pthread-offsets.h: Likewise.
* sysdeps/tile/nptl/pthread-offsets.h: Likewise.
* sysdeps/x86_64/nptl/pthread-offsets.h: Likewise.
Signed-off-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Add a new header file, sysdeps/x86/sysdep.h, for common assembly code
macros between i386 and x86-64. Tested on i686 and x86-64. There are
no differences in outputs of "readelf -a" and "objdump -dw" on all glibc
shared objects before and after the patch.
* sysdeps/i386/sysdep.h: Include <sysdeps/x86/sysdep.h> instead
of <sysdeps/generic/sysdep.h>.
(ALIGNARG): Removed.
(ASM_SIZE_DIRECTIVE): Likewise.
(ENTRY): Likewise.
(END): Likewise.
(ENTRY_CHK): Likewise.
(END_CHK): Likewise.
(syscall_error): Likewise.
(mcount): Likewise.
(PSEUDO_END): Likewise.
(L): Likewise.
(atom_text_section): Likewise.
* sysdeps/x86/sysdep.h: New file.
* sysdeps/x86_64/sysdep.h: Include <sysdeps/x86/sysdep.h> instead
of <sysdeps/generic/sysdep.h>.
(ALIGNARG): Removed.
(ASM_SIZE_DIRECTIVE): Likewise.
(ENTRY): Likewise.
(END): Likewise.
(ENTRY_CHK): Likewise.
(END_CHK): Likewise.
(syscall_error): Likewise.
(mcount): Likewise.
(PSEUDO_END): Likewise.
(L): Likewise.
(atom_text_section): Likewise.
i586 strcpy.S used a clever trick with LEA to implement jump table:
/* ECX has the last 2 bits of the address of source - 1. */
andl $3, %ecx
call 2f
2: popl %edx
/* 0xb is the distance between 2: and 1:. */
leal 0xb(%edx,%ecx,8), %ecx
jmp *%ecx
.align 8
1: /* ECX == 0 */
orb (%esi), %al
jz L(end)
stosb
xorl %eax, %eax
incl %esi
/* ECX == 1 */
orb (%esi), %al
jz L(end)
stosb
xorl %eax, %eax
incl %esi
/* ECX == 2 */
orb (%esi), %al
jz L(end)
stosb
xorl %eax, %eax
incl %esi
/* ECX == 3 */
L(1): movl (%esi), %ecx
leal 4(%esi),%esi
This fails if there are instruction length changes before L(1):. This
patch replaces it with conditional branches:
cmpb $2, %cl
je L(Src2)
ja L(Src3)
cmpb $1, %cl
je L(Src1)
L(Src0):
which have similar performance and work with any instruction lengths.
Tested on i586 and i686 with and without --disable-multi-arch.
[BZ #22353]
* sysdeps/i386/i586/strcpy.S (STRCPY): Use conditional branches.
(1): Renamed to ...
(L(Src0)): This.
(L(Src1)): New.
(L(Src2)): Likewise.
(L(1)): Renamed to ...
(L(Src3)): This.
