The powerpcspe GCC port has been obsoleted in GCC 8 for not having had
the removal of code for non-SPE processors completed. This patch
accordingly arranges for build-many-glibcs.py to configure GCC with
--enable-obsolete for affected configurations. This is temporary;
either the port gets cleaned up and unobsoleted in GCC and the
configure option can be removed, or the port gets removed in GCC and
we should remove the corresponding glibc support.
Tested with build-many-glibcs.py for the affected configurations.
* scripts/build-many-glibcs.py (Context.add_all_configs): Use
--enable-obsolete for powerpc-linux-gnuspe.
* sysdeps/mach/include/lock-intern.h: Move to include/.
* sysdeps/mach/include/mach.h: Move to include/.
* sysdeps/mach/include/mach/mig_support.h: Move to include/mach/.
* sysdeps/mach/include/mach_error.h: Move to include/.
This patch removes the ununsed ARM code path for armv6t2 memchr and
strlen and armv7 memch and strcmp. In all implementation, the ARM
code is not used in any possible build (unless glibc is explicit
build with the non-documented NO_THUMB compiler flag) and for armv7
the resulting code either produces wrong results (memchr) and throw
build error (strcmp).
Checked on arm-linux-gnueabihf built targeting both armv6 and
armv7.
* sysdeps/arm/armv6t2/memchr.S (memchr): Remove ARM code path.
* sysdeps/arm/armv6t2/strlen.S (memchr): Likewise.
* sysdeps/arm/armv7/multiarch/memchr_neon.S (memchr): Likewise.
* sysdeps/arm/armv7/strcmp.S (strcmp): Likewise.
Adds a fast path to e_exp.c when |x| < 1.03972053527832.
When values are tested in isolation, reduction in execution
time is: aarch 30%, sparc 18%, x86 37%.
When comparing benchtests/bench.out which includes values
outside that range, the gains are:
aarch 8%, sparc 5%, x86 9%.
make check is clean (no increase in ulp for any math test).
Testing 20M values for each rounding mode in that range shows
approximately one in 200 values is off by 1 ulp. No value tested
for exp(x) changed by 2 or more ulp.
No observed change in performance or accuracy for x outside
fast path range.
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.
Linux 4.16 does not add any new syscalls; this patch updates the
version number in syscall-names.list to reflect that it's still
current for 4.16.
Tested for x86_64 (compilation with build-many-glibcs.py, using Linux
4.16).
* sysdeps/unix/sysv/linux/syscall-names.list: Update kernel
version to 4.16.
The recent commit b4a5d26d88
"linux: Consolidate sigaction implementation" changed the definition
of struct sigaction for s390 (31bit). Unfortunately the order of the
fields were wrong.
This leads to blocking testcases e.g. nptl/tst-sem11.
A thread which blocks due to sem_wait() is cancelled via pthread_cancel()
and the signal-handler sigcancel_handler (see <glibc-src>/nptl/nptl-init.c
is called.
But it just returns as the siginfo_t argument is not setup by the kernel.
Then the main-thread is blocking due to pthread_join().
The flag SA_SIGINFO is set in sa_flags in struct sigaction and
is copied to the "kernel_sigaction.h" struct by the sigaction() call,
but due to the wrong ordering of the struct fields,
the kernel does not recognize it.
This patch consolidates Linux readdir{64}{_r} implementation on just
the default sysdeps/unix/sysv/linux/readdir{64}{_r}.c ones. The
default implementation handle the Linux requirements:
* readdir{_r} is only built for _DIRENT_MATCHES_DIRENT64 being 0.
* readdir64{_r} is always built and aliased to readdir{_r} for
ABI that define _DIRENT_MATCHES_DIRENT64.
* A compat symbol is added for readdir64{_r} for ABI that used to
export the old non-LFS version.
Checked on aarch64-linux-gnu, x86_64-linux-gnu, i686-linux-gnu,
sparcv9-linux-gnu, sparc64-linux-gnu, powerpc-linux-gnu, and
powerpc64le-linux-gnu.
* sysdeps/posix/readdir.c (__READDIR, __GETDENTS, DIRENTY_TYPE,
__READDIR_ALIAS): Undefine after usage.
* sysdeps/posix/readdir_r.c (__READDIR_R, __GETDENTS, DIRENT_TYPE,
__READDIR_R_ALIAS): Likewise.
* sysdeps/unix/sysv/linux/arm/readdir64.c: Remove file.
* sysdeps/unix/sysv/linux/arm/readdir64_r.c: Likewise.
* sysdeps/unix/sysv/linux/m68k/readdir64.c: Likewise.
* sysdeps/unix/sysv/linux/m68k/readdir64_r.c: Likewise.
* sysdeps/unix/sysv/linux/powerpc/readdir64.c: Likewise.
* sysdeps/unix/sysv/linux/powerpc/readdir64_r.c: Likewise.
* sysdeps/unix/sysv/linux/i386/readdir64.c: Likewise.
* sysdeps/unix/sysv/linux/i386/readdir64_r.c: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/readdir64.c: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/readdir64_r.c: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/readdir64.c: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/readdir64_r.c: Likewise.
* sysdeps/unix/sysv/linux/wordsize-64/readdir.c: Likewise.
* sysdeps/unix/sysv/linux/wordsize-64/readdir64.c: Likewise.
* sysdeps/unix/sysv/linux/wordsize-64/readdir64_r.c: Likewise.
* sysdeps/unix/sysv/linux/wordsize-64/readdir_r.c: Likewise.
* sysdeps/unix/sysv/linux/readdir.c: New file.
* sysdeps/unix/sysv/linux/readdir_r.c: Likewise.
* sysdeps/unix/sysv/linux/readdir64.c: Add compat symbol if required.
* sysdeps/unix/sysv/linux/readdir64_r.c: Likewise.
This patch consolidates all Linux sigaction implementations on the default
sysdeps/unix/sysv/linux/sigaction.c. The idea is remove redundant code
and simplify new ports addition by following the current generic
Linux User API (UAPI).
The UAPI for new ports defines a generic extensible sigaction struct as:
struct sigaction
{
__sighandler_t sa_handler;
unsigned long sa_flags;
#ifdef SA_RESTORER
void (*sa_restorer) (void);
#endif
sigset_t sa_mask;
};
Where SA_RESTORER is just placed for compatibility reasons (news ports
should not add it). A similar definition is used on generic
kernel_sigaction.h.
The user exported sigaction definition is not changed, so for most
architectures it requires an adjustment to kernel expected one for the
syscall.
The main changes are:
- All architectures now define and use a kernel_sigaction struct meant
for the syscall, even for the architectures where the user sigaction
has the same layout of the kernel expected one (s390-64 and ia64).
Although it requires more work for these architectures, it simplifies
the generic implementation. Also, sigaction is hardly a hotspot where
micro optimization would play an important role.
- The generic kernel_sigaction definition is now aligned with expected
UAPI one for newer ports, where SA_RESTORER and sa_restorer are not
expected to be defined. This means adding kernel_sigaction for
current architectures that does define it (m68k, nios2, powerpc, s390,
sh, sparc, and tile) and which rely on previous generic definition.
- Remove old MIPS usage of sa_restorer. This was removed since 2.6.27
(2957c9e61ee9c - "[MIPS] IRIX: Goodbye and thanks for all the fish").
- The remaining arch-specific sigaction.c are to handle ABI idiosyncrasies
(like SPARC kernel ABI for rt_sigaction that requires an additional
stub argument).
So for new ports the generic implementation should work if its uses
Linux UAPI. If SA_RESTORER is still required (due some architecture
limitation), it should define its own kernel_sigaction.h, define it and
include generic header (assuming it still uses the default generic kernel
layout).
Checked on x86_64-linux-gnu, i686-linux-gnu, arm-linux-gnueabihf,
aarch64-linux-gnu, sparc64-linux-gnu, sparcv9-linux-gnu, powerpc-linux-gnu,
powerpc64-linux-gnu, ia64-linux-gnu and alpha-linux-gnu. I also checked the
build on all remaining affected ABIs.
* sysdeps/unix/sysv/linux/aarch64/sigaction.c: Use default Linux version
as base implementation.
* sysdeps/unix/sysv/linux/arm/sigaction.c: Likewise.
* sysdeps/unix/sysv/linux/i386/sigaction.c: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/sigaction.c: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/sigaction.c: Likewise.
* sysdeps/unix/sysv/linux/x86_64/sigaction.c: Likewise.
* sysdeps/unix/sysv/linux/alpha/kernel_sigaction.h: Add include guards,
remove unrequired definitions and update comments.
* sysdeps/unix/sysv/linux/kernel_sigaction.h: Likewise.
* sysdeps/unix/sysv/linux/mips/kernel_sigaction.h: Likewise.
* sysdeps/unix/sysv/linux/ia64/kernel_sigaction.h: New file.
* sysdeps/unix/sysv/linux/m68k/kernel_sigaction.h: Likewise.
* sysdeps/unix/sysv/linux/nios2/kernel_sigaction.h: Likewise.
* sysdeps/unix/sysv/linux/powerpc/kernel_sigaction: Likewise.
* sysdeps/unix/sysv/linux/s390/kernel_sigaction.h: Likewise.
* sysdeps/unix/sysv/linux/sh/kernel_sigaction.h: Likewise.
* sysdeps/unix/sysv/linux/sparc/kernel_sigaction.h: Likewise.
* sysdeps/unix/sysv/linux/tile/kernel_sigaction.h: Likewise.
* sysdeps/unix/sysv/linux/ia64/sigaction.c: Remove file.
* sysdeps/unix/sysv/linux/mips/sigaction.c: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/sigaction.c: Likewise.
* sysdeps/unix/sysv/linux/sigaction.c: Add STUB, SET_SA_RESTORER,
and RESET_SA_RESTORER hooks.
The example did not work because the null byte was not converted, and
mbrtowc was called with a zero-length input string. This results in a
(size_t) -2 return value, so the function always returns NULL.
The size computation for the heap allocation of the result was
incorrect because it did not deal with integer overflow.
Error checking was missing, and the allocated memory was not freed on
error paths. All error returns now set errno. (Note that there is an
assumption that free does not clobber errno.)
The slightly unportable comparision against (size_t) -2 to catch both
(size_t) -1 and (size_t) -2 return values is gone as well.
A null wide character needs to be stored in the result explicitly, to
terminate it.
The description in the manual is updated to deal with these finer
points. The (size_t) -2 behavior (consuming the input bytes) matches
what is specified in ISO C11.
* sysdeps/powerpc/fpu/libm-test-ulps: Increase double-precision
sin, cos and sincos to 1 ULP.
Signed-off-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
Do not relocate absolute symbols by the base address. Such symbols have
SHN_ABS as the section index and their value is not supposed to be
affected by relocation as per the ELF gABI[1]:
"SHN_ABS
The symbol has an absolute value that will not change because of
relocation."
The reason for our non-conformance here seems to be an old SysV linker
bug causing symbols like _DYNAMIC to be incorrectly emitted as absolute
symbols[2]. However in a previous discussion it was pointed that this
is seriously flawed by preventing the lone purpose of the existence of
absolute symbols from being used[3]:
"On the contrary, the only interpretation that makes sense to me is that
it will not change because of relocation at link time or at load time.
Absolute symbols, from the days of the earliest linking loaders, have
been used to represent addresses that are outside the address space of
the module (e.g., memory-mapped addresses or kernel gateway pages).
They've even been used to represent true symbolic constants (e.g.,
system entry point numbers, sizes, version numbers). There's no other
way to represent a true absolute symbol, while the meaning you seek is
easily represented by giving the symbol a non-negative st_shndx value."
and we ought to stop supporting our current broken interpretation.
Update processing for dladdr(3) and dladdr1(3) so that SHN_ABS symbols
are ignored, because under the corrected interpretation they do not
represent addresses within a mapped file and therefore are not supposed
to be considered.
References:
[1] "System V Application Binary Interface - DRAFT - 19 October 2010",
The SCO Group, Section "Symbol Table",
<http://www.sco.com/developers/gabi/2012-12-31/ch4.symtab.html>
[2] Alan Modra, "Absolute symbols"
<https://sourceware.org/ml/binutils/2012-05/msg00019.html>
[3] Cary Coutant, "Re: Absolute symbols"
<https://sourceware.org/ml/binutils/2012-05/msg00020.html>
[BZ #19818]
* sysdeps/generic/ldsodefs.h (SYMBOL_ADDRESS): Handle SHN_ABS
symbols.
* elf/dl-addr.c (determine_info): Ignore SHN_ABS symbols.
* elf/tst-absolute-sym.c: New file.
* elf/tst-absolute-sym-lib.c: New file.
* elf/tst-absolute-sym-lib.lds: New file.
* elf/Makefile (tests): Add `tst-absolute-sym'.
(modules-names): Add `tst-absolute-sym-lib'.
(LDLIBS-tst-absolute-sym-lib.so): New variable.
($(objpfx)tst-absolute-sym-lib.so): New dependency.
($(objpfx)tst-absolute-sym): New dependency.
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>
Three of the functions defined by internal-signals.h were not actually
fulfilling their contracts when the sysdeps/generic version of that
file was used. Also, the Linux version included several more headers
than the generic version, which is the root cause of a build failure
on Hurd (already addressed in another way, but I think it is proper to
make the headers match).
* sysdeps/generic/internal-signals.h: Include signal.h,
sigsetops.h, and stdbool.h.
(__libc_signal_block_all): Actually block all signals.
(__libc_signal_block_app): Likewise.
(__libc_signal_restore_set): Actually restore the signal mask.
This patch filters out the internal NPTL signals (SIGCANCEL/SIGTIMER and
SIGSETXID) from signal functions. GLIBC on Linux requires both signals to
proper implement pthread cancellation, posix timers, and set*id posix
thread synchronization.
And not filtering out the internal signal is troublesome:
- A conformant program on a architecture that does not filter out the
signals might inadvertently disable pthread asynchronous cancellation,
set*id synchronization or posix timers.
- It might also to security issues if SIGSETXID is masked and set*id
functions are called (some threads might have effective user or group
id different from the rest).
The changes are basically:
- Change __is_internal_signal to bool and used on all signal function
that has a signal number as input. Also for signal function which accepts
signals sets (sigset_t) it assumes that canonical function were used to
add/remove signals which lead to some input simplification.
- Fix tst-sigset.c to avoid check for SIGCANCEL/SIGTIMER and SIGSETXID.
It is rewritten to check each signal indidually and to check realtime
signals using canonical macros.
- Add generic __clear_internal_signals and __is_internal_signal
version since both symbols are used on generic implementations.
- Remove superflous sysdeps/nptl/sigfillset.c.
- Remove superflous SIGTIMER handling on Linux __is_internal_signal
since it is the same of SIGCANCEL.
- Remove dangling define and obvious comment on nptl/sigaction.c.
Checked on x86_64-linux-gnu.
[BZ #22391]
* nptl/sigaction.c (__sigaction): Use __is_internal_signal to
check for internal nptl signals.
* nptl/sigaction.c (__sigaction): Likewise.
* signal/sigaddset.c (sigaddset): Likewise.
* signal/sigdelset.c (sigdelset): Likewise.
* sysdeps/posix/signal.c (__bsd_signal): Likewise.
* sysdeps/posix/sigset.c (sigset): Call and check sigaddset return
value.
* signal/sigfillset.c (sigfillset): User __clear_internal_signals
to filter out internal nptl signals.
* signal/tst-sigset.c (do_test): Check ech signal indidually and
also check realtime signals using standard macros.
* sysdeps/generic/internal-signals.h (__clear_internal_signals,
__is_internal_signal, __libc_signal_block_all,
__libc_signal_block_app, __libc_signal_restore_set): New functions.
* sysdeps/nptl/sigfillset.c: Remove file.
* sysdeps/unix/sysv/linux/internal-signals.h (__is_internal_signal):
Change return to bool.
(__clear_internal_signals): Remove SIGTIMER clean since it is
equal to SIGCANEL on Linux.
* sysdeps/unix/sysv/linux/sigtimedwait.c (__sigtimedwait): Assume
signal set was constructed using standard functions.
Reported-by: Yury Norov <ynorov@caviumnetworks.com>
Refactor the sincos implementation - rather than rely on odd partial inlining
of preprocessed portions from sin and cos, explicitly write out the cases.
This makes sincos much easier to maintain and provides an additional 16-20%
speedup between 0 and 2^27. The overall speedup of sincos is 48% over this range.
Between 0 and PI it is 66% faster.
* sysdeps/ieee754/dbl-64/s_sin.c (__sin): Cleanup ifdefs.
(__cos): Likewise.
* sysdeps/ieee754/dbl-64/s_sin.c (__sincos): Refactor using the same
logic as sin and cos.
Refactor duplicated code into do_sin. Since all calls to do_sin use copysign to
set the sign of the result, move it inside do_sin. Small inputs use a separate
polynomial, so move this into do_sin as well (the check is based on the more
conservative case when doing large range reduction, but could be relaxed).
* sysdeps/ieee754/dbl-64/s_sin.c (do_sin): Use TAYLOR_SIN for small
inputs. Return correct sign.
(do_sincos): Remove small input check before do_sin, let do_sin set
the sign.
(__sin): Likewise.
(__cos): Likewise.
For huge inputs use the improved do_sincos function as well. Now no cases use
the correction factor returned by do_sin, do_cos and TAYLOR_SIN, so remove it.
* sysdeps/ieee754/dbl-64/s_sin.c (TAYLOR_SIN): Remove cor parameter.
(do_cos): Remove corp parameter and calculations.
(do_sin): Likewise.
(do_sincos): Remove cor variable.
(__sin): Use do_sincos for huge inputs.
(__cos): Likewise.
* sysdeps/ieee754/dbl-64/s_sincos.c (__sincos): Likewise.
(reduce_and_compute_sincos): Remove unused function.
This patch improves the accuracy of the range reduction. When the input is
large (2^27) and very close to a multiple of PI/2, using 110 bits of PI is not
enough. Improve range reduction accuracy to 136 bits. As a result the special
checks for results close to zero can be removed. The ULP of the polynomials is
at worst 0.55ULP, so there is no reason for the slow functions, and they can be
removed.
* sysdeps/ieee754/dbl-64/s_sin.c (reduce_sincos_1): Rename to
reduce_sincos, improve accuracy to 136 bits.
(do_sincos_1): Rename to do_sincos, remove fallbacks to slow functions.
(__sin): Use improved reduction and simplified do_sincos calculation.
(__cos): Likewise.
* sysdeps/ieee754/dbl-64/s_sincos.c (__sincos): Likewise.
This patch removes the large range reduction code and defers to the huge range
reduction code. The first level range reducer supports inputs up to 2^27,
which is way too large given that inputs for sin/cos are typically small
(< 10), and optimizing for a smaller range would give a significant speedup.
Input values above 2^27 are practically never used, so there is no reason for
supporting range reduction between 2^27 and 2^48. Removing it significantly
simplifies code and enables further speedups. There is about a 2.3x slowdown
in this range due to __branred being extremely slow (a better algorithm could
easily more than double performance).
* sysdeps/ieee754/dbl-64/s_sin.c (reduce_sincos_2): Remove function.
(do_sincos_2): Likewise.
(__sin): Remove middle range reduction case.
(__cos): Likewise.
* sysdeps/ieee754/dbl-64/s_sincos.c (__sincos): Remove middle range
reduction case.
This series of patches removes the slow patchs from sin, cos and sincos.
Besides greatly simplifying the implementation, the new version is also much
faster for inputs up to PI (41% faster) and for large inputs needing range
reduction (27% faster).
ULP is ~0.55 with no errors found after testing 1.6 billion inputs across most
of the range with mpsin and mpcos. The number of incorrectly rounded results
(ie. ULP >0.5) is at most ~2750 per million inputs between 0.125 and 0.5,
the average is ~850 per million between 0 and PI.
Tested on AArch64 and x86_64 with no regressions.
The first patch removes the slow paths for the cases where the input is small
and doesn't require range reduction. Update ULP tables for sin, cos and sincos
on AArch64 and x86_64.
* sysdeps/aarch64/libm-test-ulps: Update ULP for sin, cos, sincos.
* sysdeps/ieee754/dbl-64/s_sin.c (__sin): Remove slow paths for small
inputs.
(__cos): Likewise.
* sysdeps/x86_64/fpu/libm-test-ulps: Update ULP for sin, cos, sincos.
