Some of the functions in msun can be implemented using a compiler
builtin function to generate a small number of instructions. Implement
this support in fma, fmax, fmin, and sqrt on arm64.
Care must be taken as the builtin can be implemented as a function
call on some architectures that lack direct support. In these cases
we need to use the original code path.
As we don't set errno on failure build with -fno-math-errno so the
toolchain doesn't convert a builtin into a function call when it
detects a failure, e.g. gcc will add a call to sqrt when the input
is negative leading to an infinite loop.
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D32801
The change implements cexpl() for both ld80 and ld128 architectures.
Testing was done on x86_64 and aarch64 systems.
Along the way sincos[fl]() use an optimization that reduces the argument
to being done one rather than twice. This optimization actually pointed
to a bug in the ld128 version of sincosl(), which is now fixed. In
addition, the minmax polynomial coefficients for sincosl() have been
updated.
A concise log of the file-by-file changes follows.
* include/complex.h:
. Add a prototype for cexpl().
* lib/msun/Makefile:
. Add s_cexpl.c to the build.
. Setup a link for cexpl.3 to cexp.3.
* lib/msun/Symbol.map:
. Expose cexpl symbol in libm shared library.
* lib/msun/ld128/s_cexpl.c:
* Implementation of cexpl() for 128-bit long double architectures.
Tested on an aarch64 system.
* lib/msun/ld80/s_cexpl.c:
* Implementation of cexpl() for Intel 80-bit long double.
* lib/msun/man/cexp.3:
. Document cexpl().
* lib/msun/man/complex.3:
. Add a BUGS section about cpow[fl].
* lib/msun/src/s_cexp.c:
. Include float.h for weak references on 53-bit long double targets.
. Use sincos() to reduce argument reduction cost.
* lib/msun/src/s_cexpf.c:
. Use sincosf() to reduce argument reduction cost.
* lib/msun/src/k_sincosl.h:
. Catch up with the new minmax polynomial coefficients for the kernel for
the 128-bit cosl() implementation.
. BUG FIX: *cs was used where *sn should have been. This means that sinl()
was no computed correctly when iy != 0.
* lib/msun/src/s_cosl.c:
. Include fpmath.h to get access to IEEEl2bits.
. Replace M_PI_4 with pio4, a 64-bit or 113-bit approximation for pi / 4.
PR: 216862
MFC after: 1 week
Both IEEE-754 2008 and ISO/IEC TS 18661-4 define the half-cycle
trignometric functions cospi, sinpi, and tanpi. The attached
patch implements cospi[fl], sinpi[fl], and tanpi[fl]. Limited
testing on the cospi and sinpi reveal a max ULP less than 0.89;
while tanpi is more problematic with a max ULP less than 2.01
in the interval [0,0.5]. The algorithms used in these functions
are documented in {ks}_cospi.c, {ks}_sinpi.c, and s_tanpi.c.
Note. I no longer have access to a system with ld128 and
adequate support to compile and test the ld128 implementations
of these functions. Given the almost complete lack of input from
others on improvements to libm, I doubt that anyone cares. If
someone does care, the ld128 files contain a number of FIXME comments,
and in particular, while the polynomial coefficients are given
I did not update the polynomial algorithms to properly use the
coefficients.
PR: 218514
MFC after: 2 weeks
This avoids build failures due to the clang 12 warning:
'#pragma FENV_ACCESS' is not supported on this target - ignored
Clang 12 currently emits this warning for all non-x86 architectures.
While this can result in incorrect code generation (e.g. on AArch64 some
exceptions are not raised as expected), this is a pre-existing issue and
we should not fail the build due to this warning.
Reviewed By: dim, emaste
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D29743
After 3b00222f15, it turns out that clang only supports strict
floating point semantics for SystemZ and x86 at the moment, while for
other architectures it is still experimental.
Therefore, only use -fp-exception-behavior=maytrap on x86 for now,
otherwise this option results in "error: overriding currently
unsupported use of floating point exceptions on this target
[-Werror,-Wunsupported-floating-point-opt]" on other architectures.
Fixes: 3b00222f15
PR: 254911
MFC after: 1 week
When using clang with x86_64 CPUs that support AVX, some floating point
transformations may raise exceptions that would not have been raised by
the original code. To avoid this, use the -fp-exception-behavior=maytrap
flag, introduced in clang 10.0.0.
In particular, this fixes a number of test failures with ctanhf(3) and
ctanf(3), when libm is compiled with -mavx. An unexpected FE_INVALID
exception is then raised, because clang emits vdivps instructions to
perform certain divides. (The vdivps instruction operates on multiple
single-precision float operands simultaneously, but the exceptions may
be influenced by unused parts of the XMM registers. In this particular
case, it was calculating 0 / 0, which results in FE_INVALID.)
If -fp-exception-behavior=maytrap is specified however, clang uses
vdivss instructions instead, which work on one operand, and should not
raise unexpected exceptions.
Reported by: olivier
Reviewed by: arichardson
PR: 254911
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D29686
Assume gcc is at least 6.4, the oldest xtoolchain in the ports tree.
Assume clang is at least 6, which was in 11.2-RELEASE. Drop conditions
for older compilers.
Reviewed by: imp (earlier version), emaste, jhb
MFC after: 2 weeks
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D24802
This is a follow-up to r336299.
* lib/msun/Makefile:
. Remove polevll.c
* lib/msun/ld80/e_powl.c:
. Copy contents of polevll.c to here. This is the only consumer of
these functions. Make functions 'static inline'.
. Make reducl a 'static inline' function.
* lib/msun/man/exp.3:
. Remove BUGS section that no longer applies.
* lib/msun/src/math_private.h:
. Remove prototypes of __p1evll() and __polevll()
* lib/msun/src/s_cpow.c:
* lib/msun/src/s_cpowf.c:
* lib/msun/src/s_cpowl.c
. Include math_private.h.
. Use the CMPLX macro from either C99 or math_private.h (depends on
compiler support) instead of the problematic use of complex I.
Submitted by: Steve Kargl <sgk@troutmask.apl.washington.edu>
PR: 229876
MFC after: 1 week
cc1: warnings being treated as errors
/usr/src/lib/msun/src/s_cpow.c: In function 'cpow':
/usr/src/lib/msun/src/s_cpow.c:63: warning: implicit declaration of function 'CMPLX'
This is a follow-up to r336299.
* lib/msun/Makefile:
. Remove polevll.c
* lib/msun/ld80/e_powl.c:
. Copy contents of polevll.c to here. This is the only consumer of
these functions. Make functions 'static inline'.
. Make reducl a 'static inline' function.
* lib/msun/man/exp.3:
. Remove BUGS section that no longer applies.
* lib/msun/src/math_private.h:
. Remove prototypes of __p1evll() and __polevll()
* lib/msun/src/s_cpow.c:
* lib/msun/src/s_cpowf.c:
* lib/msun/src/s_cpowl.c
. Use the CMPLX macro from either C99 or math_private.h (depends of
compiler support) instead of the problematic use of complex I.
Submitted by: Steve Kargl <sgk@troutmask.apl.washington.edu>
PR: 229876
MFC after: 1 week
This corresponds to the latest status (hasn't changed in 9+
years) from openbsd of ld80/ld128 powl, and source cpowf, cpow,
cpowl (the complex power functions for float complex, double
complex, and long double complex) which are required for C99
compliance and were missing from FreeBSD. Also required for
some numerical codes using complex numbered Hamiltonians.
Thanks to jhb for tracking down the issue with making
weak_reference compile on powerpc.
When asked to review, bde said "I don't like it" - but
provided no actionable feedback or superior implementations.
Discussed with: jhb
Submitted by: jmd
Differential Revision: https://reviews.freebsd.org/D15919
directories to SUBDIR.${MK_TESTS} idiom
This is being done to pave the way for future work (and homogenity) in
^/projects/make-check-sandbox .
No functional change intended.
MFC after: 1 weeks
The primary benefit of these functions is that argument
reduction is done once instead of twice in independent
calls to sin() and cos().
* lib/msun/Makefile:
. Add s_sincos[fl].c to the build.
. Add sincos.3 documentation.
. Add appropriate MLINKS.
* lib/msun/Symbol.map:
. Expose sincos[fl] symbols in dynamic libm.so.
* lib/msun/man/sincos.3:
. Documentation for sincos[fl].
* lib/msun/src/k_sincos.h:
. Kernel for sincos() function. This merges the individual kernels
for sin() and cos(). The merger offered an opportunity to re-arrange
the individual kernels for better performance.
* lib/msun/src/k_sincosf.h:
. Kernel for sincosf() function. This merges the individual kernels
for sinf() and cosf(). The merger offered an opportunity to re-arrange
the individual kernels for better performance.
* lib/msun/src/k_sincosl.h:
. Kernel for sincosl() function. This merges the individual kernels
for sinl() and cosl(). The merger offered an opportunity to re-arrange
the individual kernels for better performance.
* lib/msun/src/math.h:
. Add prototytpes for sincos[fl]().
* lib/msun/src/math_private.h:
. Add RETURNV macros. This is needed to reset fpsetprec on I386
hardware for a function with type void.
* lib/msun/src/s_sincos.c:
. Implementation of sincos() where sin() and cos() were merged into
one routine and possibly re-arranged for better performance.
* lib/msun/src/s_sincosf.c:
. Implementation of sincosf() where sinf() and cosf() were merged into
one routine and possibly re-arranged for better performance.
* lib/msun/src/s_sincosl.c:
. Implementation of sincosl() where sinl() and cosl() were merged into
one routine and possibly re-arranged for better performance.
PR: 215977, 218300
Submitted by: Steven G. Kargl <sgk@troutmask.apl.washington.edu>
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D10765
the constraints on what needs to be installed in a specific to
maintain consistency during upgrades.
Create a new clibs package containing libraries that are needed
as a bare minimum for consistency.
With much help and input from: kib
Sponsored by: The FreeBSD Foundation
Since METAMODE has been added, sys.mk loads bsd.mkopt.mk which ends load loading
bsd.own.mk which then defines SHLIBDIR before all the Makefile.inc everywhere.
This makes /lib being populated again.
Reported by: many
A variant of this code has been tested on amd64/i386 for some time by
EMC/Isilon on 10-STABLE/11-CURRENT. It builds on other architectures, but the
code will remain off until it's proven it works on virtual hardware or real
hardware on other architectures
Sponsored by: EMC / Isilon Storage Division
. Hook e_lgammal[_r].c to the build.
. Create man page links for lgammal[-r].3.
* Symbol.map:
. Sort lgammal to its rightful place.
. Add FBSD_1.4 section for the new lgamal_r symbol.
* ld128/e_lgammal_r.c:
. 128-bit implementataion of lgammal_r().
* ld80/e_lgammal_r.c:
. Intel 80-bit format implementation of lgammal_r().
* src/e_lgamma.c:
. Expose lgammal as a weak reference to lgamma for platforms
where long double is mapped to double.
* src/e_lgamma_r.c:
. Use integer literal constants instead of real literal constants.
Let compiler(s) do the job of conversion to the appropriate type.
. Expose lgammal_r as a weak reference to lgamma_r for platforms
where long double is mapped to double.
* src/e_lgammaf_r.c:
. Fixed the Cygnus Support conversion of e_lgamma_r.c to float.
This includes the generation of new polynomial and rational
approximations with fewer terms. For each approximation, include
a comment on an estimate of the accuracy over the relevant domain.
. Use integer literal constants instead of real literal constants.
Let compiler(s) do the job of conversion to the appropriate type.
This allows the removal of several explicit casts of double values
to float.
* src/e_lgammal.c:
. Wrapper for lgammal() about lgammal_r().
* src/imprecise.c:
. Remove the lgamma.
* src/math.h:
. Add a prototype for lgammal_r().
* man/lgamma.3:
. Document the new functions.
Reviewed by: bde
. Add s_erfl.c to building libm.
. Add MLINKS for erfl.3 and erfcl.3.
* Symbol.map:
. Move erfl and erfcl to their proper location.
* ld128/s_erfl.c:
. Implementations of erfl and erfcl in the IEEE 754 128-bit format.
* ld80/s_erfl.c:
. Implementations of erfl and erfcl in the Intel 80-bit format.
* man/erf.3:
. Document the new functions.
. While here, remove an incomplete sentence.
* src/imprecise.c:
. Remove the stupidity of mapping erfl and erfcl to erf and erfc.
* src/math.h:
. Move the declarations of erfl and erfcl to their proper place.
* src/s_erf.c:
. For architectures where double and long double are the same
floating point format, use weak references to map erfl to
erf and ercl to erfc.
Reviewed by: bde (many earlier versions)
. Hook coshl, sinhl, and tanhl into libm.
. Create symbolic links for corresponding manpages.
. While here remove a nearby extraneous space.
* Symbol.map:
* src/math.h:
. Move coshl, sinhl, and tanhl to their proper locations.
* man/cosh.3:
* man/sinh.3:
* man/tanh.3:
. Update the manpages.
* src/e_cosh.c:
* src/e_sinh.c:
* src/s_tanh.c:
. Add weak reference for LBDL_MANT_DIG==53 targets.
* src/imprecise.c:
. Remove the coshl, sinhl, and tanhl kludge.
* src/e_coshl.c:
. ld80 and ld128 implementation of coshl().
* src/e_sinhl.c:
. ld80 and ld128 implementation of sinhl().
* src/s_tanhl.c:
. ld80 and ld128 implementation of tanhl().
Obtained from: bde (mostly), das and kargl
These are weak and so can be replaced by other versions in applications
that choose to do so, and will give a linker warning when used so that
applications that rely on the extra precision can avoid them.
Note that since the C/C++ specs only guarantee that long double has
precision equal to double, code that actually relies on these functions
having greater precision is unportable at best and broken at worst.
are workarounds for various symptoms of the problem described in clang
bugs 3929, 8100, 8241, 10409, and 12958.
The regression tests did their job: they failed, someone brought it
up on the mailing lists, and then the issue got ignored for 6 months.
Oops. There may still be some regressions for functions we don't have
test coverage for yet.
use softfloat.
Thanks to Ian Lepore for testing and debugging this patch. The fenv
regression tests pass (at least for Ian's arm chip) with this change.
exp(x) scaled down by some factor, and the challenge is doing this
accurately when exp(x) would overflow. This change replaces all of
the tricks we've been using with common __ldexp_exp() and
__ldexp_cexp() routines that handle all the scaling.
bde plans to improve on this further by moving the guts of exp() into
k_exp.c and handling the scaling in a more direct manner. But the
current approach is simple and adequate for now.
with r219571 and re-enable building of cbrtl.
Implement the long double version for the cube root function, cbrtl.
The algorithm uses Newton's iterations with a crude estimate of the
cube root to converge to a result.
Reviewed by: bde
Approved by: das
