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
When compiling parts of math.h with clang using a C standard before C11,
and using -pedantic, it will result in warnings similar to:
bug254714.c:5:11: warning: '_Generic' is a C11 extension [-Wc11-extensions]
return !isfinite(1.0);
^
/usr/include/math.h:111:21: note: expanded from macro 'isfinite'
^
/usr/include/math.h:82:39: note: expanded from macro '__fp_type_select'
^
This is because the block that enables use of _Generic is conditional
not only on C11, but also on whether the compiler advertises support for
C generic selections via __has_extension(c_generic_selections).
To work around the warning without having to pessimize the code, use the
__extension__ keyword, which is supported by both clang and gcc. While
here, remove the check for __clang__, as _Generic has been supported for
a long time by gcc too now.
Reported by: yuri
PR: 254714
MFC after: 1 week
The man page says "The feenableexcept(), fedisableexcept(), and
fegetexcept() functions return a bitmap of the exceptions that were
unmasked prior to the call.", so we should return zero not -1.
Reviewed By: mhorne
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D29386
After increasing the lib/msun/tests WARNS to 6, this triggers a
compilation error for RISC-V.
Fixes: 87d65c747a ("lib/msun: Allow building tests with WARNS=6")
Reported by: Jenkins
The LLVM bug was fixed a long time ago and with D29076 this test actually
passes now.
Reviewed By: andrew
Differential Revision: https://reviews.freebsd.org/D29092
If long double has more than 64 mantissa bits, using uint64_t to hold the
mantissa bits will truncate the value and result in test failures. To fix
this problem use __uint128_t since all platforms that have
__LDBL_MANT_DIG__ > 64 also have compiler support for 128-bit integers.
Reviewed By: rlibby
Differential Revision: https://reviews.freebsd.org/D29076
I only tested the WARNS=6 change on AArch64 and AMD64, but this file has
unused functions for architectures with LDBL_PREC == 53.
While touching this file change the LDBL_PREC == 53 checks to i386 checks.
The long double tests should only be disabled for i386 (due to the rather
odd rounding mode that it uses) not all architectures where long double
is the same as double.
PR: 205449
Fixes: 87d65c747a ("lib/msun: Allow building tests with WARNS=6")
Reported by: Jenkins
Some CPUs (e.g. AArch64 QEMU) cannot trap on floating point exceptions and
therefore ignore the writes to the floating point control register inside
feenableexcept(). If no exceptions are enabled after
feenableexcept(FE_ALL_EXCEPT), we can assume that the CPU does not
support exceptions and we can then skip the test.
Reviewed By: dim
Differential Revision: https://reviews.freebsd.org/D29095
These appears to have been resolved by compiling the test with -fno-builtin
and/or using a newer compiler.
PR: 208703
Reviewed By: ngie
Differential Revision: https://reviews.freebsd.org/D28884
This provides better error messages that just an assertion failure and
also makes it easier to mark individual tests as XFAIL.
It was also helpful when coming up with D28786 and D28787.
Differential Revision: https://reviews.freebsd.org/D28798
Apparently GCC only supports arithmetic expressions that use static
const variables in initializers starting with GCC8. To keep older
versions happy use a macro instead.
Fixes: 221622ec0c ("lib/msun: Avoid FE_INEXACT for x86 log2l/log10l")
Reported by: Jenkins
Reviewed By: imp
Differential Revision: https://reviews.freebsd.org/D29233
The existing code masked off all bits that it didn't know about. To be
future-proof, we should save and restore the entire fpcr/fpsr registers.
Additionally, the existing fesetenv() was incorrectly setting the rounding
mode in fpsr instead of fpcr.
This patch stores fpcr in the high 32 bits of fenv_t and fpsr in the low
bits instead of trying to interleave them in a single 32-bit field.
Technically, this is an ABI break if you re-compile parts of your code or
pass a fenv_t between DSOs that were compiled with different versions
of fenv.h. However, I believe we should fix this since the existing code
was broken and passing fenv_t across DSOs should rarely happen.
Reviewed By: andrew
Differential Revision: https://reviews.freebsd.org/D29160
This fixes tests/lib/msun/logarithm_test after compiling the test with
-fno-builtin (D28577). Adding invln10_lo + invln10_10 results in
FE_INEXACT (for all inputs) and the same for the log2l invln2_lo + invln2_hi.
This patch avoids FE_INEXACT (for exact results such as 0) by defining a
constant and using that.
Reviewed By: dim
Differential Revision: https://reviews.freebsd.org/D28786
This caused LDBL_MANT_DIG to not be defined and therefore the scalbnl
alias was not being emitted for double==long double platforms.
Fixes: 760b2ffc ("Update scalbn* functions to the musl versions")
Reported by: Jenkins
The only diff compared to musl is a minor change to scalbnl() to replace
musl's union ldshape with union IEEEl2bits.
This fixes the scalbn tests on non-x86 (since x86 has an assembly version
that is used instead).
Musl commit messages:
commit 8c44a060243f04283ca68dad199aab90336141db
Author: Szabolcs Nagy <nsz@port70.net>
Date: Mon Apr 3 02:38:13 2017 +0200
fix scalbn when result is in the subnormal range
in nearest rounding mode scalbn could introduce double rounding error
when an intermediate value and the final result were both in the
subnormal range e.g.
scalbn(0x1.7ffffffffffffp-1, -1073)
returned 0x1p-1073 instead of 0x1p-1074, because the intermediate
computation got rounded to 0x1.8p-1023.
with the fix an intermediate value can only be in the subnormal range
if the final result is 0 which is correct even after double rounding.
(there still can be two roundings so signals may be raised twice, but
that's only observable with trapping exceptions which is not supported.)
commit 2eaed464e2080d8321d3903b71086a1ecfc4ee4a
Author: Szabolcs Nagy <nsz@port70.net>
Date: Wed Sep 4 15:52:54 2013 +0000
math: use float_t and double_t in scalbnf and scalbn
remove STRICT_ASSIGN (c99 semantics is assumed) and use the conventional
union to prepare the scaling factor (so libm.h is no longer needed)
commit 1b77b9072f374bd26eb0574b83a0d5f18d75ec60
Author: Szabolcs Nagy <nsz@port70.net>
Date: Thu Aug 15 10:07:46 2013 +0000
math: minor scalbn*.c simplification
commit c4359e01303da2755fe7e8033826b132eb3659b1
Author: Szabolcs Nagy <nsz@port70.net>
Date: Tue Nov 13 10:55:35 2012 +0100
math: excess precision fix modf, modff, scalbn, scalbnf
old code was correct only if the result was stored (without the
excess precision) or musl was compiled with -ffloat-store.
now we use STRICT_ASSIGN to work around the issue.
(see note 160 in c11 section 6.8.6.4)
commit 666271c105e4137bdfa195e217799d74143370d4
Author: Szabolcs Nagy <nsz@port70.net>
Date: Tue Nov 13 10:30:40 2012 +0100
math: fix scalbn and scalbnf on overflow/underflow
old code was correct only if the result was stored (without the
excess precision) or musl was compiled with -ffloat-store.
(see note 160 in n1570.pdf section 6.8.6.4)
commit 8051e08e10d2b739fcfcbc6bc7466e8d77fa49f1
Author: nsz <nsz@port70.net>
Date: Mon Mar 19 10:54:07 2012 +0100
simplify scalbn*.c implementations
The old scalbn.c was wrong and slow, the new one is just slow.
(scalbn(0x1p+1023,-2097) should give 0x1p-1074, but the old code gave 0)
Reviewed By: dim
Differential Revision: https://reviews.freebsd.org/D28872
This forces the compiler to emit calls to libm functions, instead of
possibly substituting pre-calculated results at compile time, which
should help to actually test those functions.
Reviewed by: emaste, arichardson, ngie
Differential Revision: https://reviews.freebsd.org/D28577
MFC after: 3 days
I did this without a full vendor update since that would cause too many
conflicts. Since these files now almost match the NetBSD sources the
next git subtree merge should work just fine.
Reviewed By: lwhsu
Differential Revision: https://reviews.freebsd.org/D28797
This applies musl commit b02eed9c4841913d690a2d0029737d72615384fe by
Szabolcs Nagy and updates the tests accordingly. This also allows
removing an XFAIL from the test.
musl commit message:
complex: fix ctanh(+-0+i*nan) and ctanh(+-0+-i*inf)
These cases were incorrect in C11 as described by
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1886.htm
PR: 217528
Reviewed By: dim
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D28578
This adjusts the factor used to scale the subnormal numbers, so it
becomes the right value after adjusting its exponent. Thanks to Steve
Kargl for finding the most elegant fix.
Also enable the hypot tests, and add a test case for this bug.
PR: 253313
MFC after: 1 week
This sprinkles a few strategic volatiles in an attempt to defeat clang's
optimization interfering with the expected floating-point exception
flags.
Reported by: lwhsu
PR: 244732
MFC after: 3 days
This tests fork()s, so if there is still data in the stdout buffer on fork
it will print it again in the child process. This was happening in the
CheriBSD CI and caused the test to complain about malformed TAP output.
Reviewed By: ngie
Differential Revision: https://reviews.freebsd.org/D28397
SVN r343917 fixed this for in-tree clang, but when building with a newer
out-of-tree clang the test was still marked as XFAIL.
Reviewed By: dim
Differential Revision: https://reviews.freebsd.org/D28390
Follow-up to r353959 and r368070: do the same for other architectures.
arm32 already seems to use its own .fnstart/.fnend directives, which
appear to be ARM-specific variants of the same thing. Likewise, MIPS
uses .frame directives.
Reviewed by: arichardson
Differential Revision: https://reviews.freebsd.org/D27387
Some platforms have additional architecture-specific floating-point flags.
Msun test cases lrint and test_fegsetenv (fenv) expects only standard flags,
so make sure to mask them appropriately.
This makes test pass on PowerPC64.
Reviewed by: jhibbits, ngie
Sponsored by: Eldorado Research Institute (eldorado.org.br)
Differential Revision: https://reviews.freebsd.org/D27202
Fix incorrect mask being used when FE_INVALID bit is wanted by user.
The problem was noticed thanks to msun fenv tests.
Reviewed by: jhibbits, luporl
Sponsored by: Eldorado Research Institute (eldorado.org.br)
Differential Revision: https://reviews.freebsd.org/D27201
The intel compiler support has badly decayed over the years. Stop
pretending that we support it. Note, I've stopped short of requiring
gcc builtin support with this commit since other compilers may be used
to build non-base software and we need to support those so more
investigation is needed before simplifying further.
by Steve Kargl:
- Use sincos[f] instead of a call to cos[f] and a call to sin[f].
- While here, alphabetize declaration.
Submitted by: sgk at troutmask.apl.washington.edu (Steve Kargl)
- Micro-optimization: use sincosl(x) instead of a call to cosl(x) and
a call to sinl(x). Argument reduction is done once not twice.
- Use a long double constant instead of an invalid double constant.
- Spell scale2 correctly
He could not test ld128, so that patch is untested.
Submitted by: sgk at troutmask.apl.washington.edu (Steve Kargl)
Some of the NetBSD contributed tests are gated behind the
__HAVE_LONG_DOUBLE flag. This flag seems to be defined only for
platforms whose long double is larger than their double. I could not
find this explicitly documented anywhere, but it is implied by the
definitions in NetBSD's sys/arch/${arch}/include/math.h headers, and the
following assertion from the UBSAN code:
#ifdef __HAVE_LONG_DOUBLE
long double LD;
ASSERT(sizeof(LD) > sizeof(uint64_t));
#endif
RISC-V has 128-bit long doubles, so enable the tests on this platform,
and update the comments to better explain the purpose of this flag.
Reviewed by: ngie
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D25419
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
These functions first appeared in the First Edition of Unix (or earlier in the
pdp-7 version). Just claim 1st Edition for all this. The pdp-7 code is too
fragmented at this point to extend history that far back.
The "for" loop on big endian was inverting all the bits instead of
just the words
Issue reported by TestSuite (msun lib nan_test case)
Submitted by: Renato Riolino <renato.riolino@eldorado.org.br>
Submitted by: Fernando Valle <fernando.valle@eldorado.org.br>
Reviewed by: pfg, alfredo
Approved by: jhibbits (mentor)
Sponsored by: Eldorado Research Institute (eldorado.org.br)
Differential Revision: https://reviews.freebsd.org/D23926
Once upon a time, sparc64 was the only ld128 architecture. However,
both aarch64 and riscv are now such architectures. Many of the
comments about how slow multiplication was on old sparc64 processors
are now no longer true. However, since no evaluation has been done for
aarch64 yet, it's unclear if they are still relevant or not. If not,
the code should be changed. If so, the comments should remove the
uncertainty.
Reviewed by: emaste@
Differential Revision: https://reviews.freebsd.org/D23658
environ(7) was in AT&T Version 7
ac(8): Add a HISTORY section
sa(8): Add a HISTORY section
sqrt(3): Add the actual sqrt function to the HISTORY section
Obtained from: OpenBSD
Submitted by: gbergling@gmail.com
Approved by: bcr@(mentor)
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D23693
In r355656, endianness handling of the floating point environment was fixed
in the PowerPC code to work as intended.
However, one bit got missed, causing feholdexcept() to mis-save the fenv.
Submitted by: Renato Riolino <renato.riolino@eldorado.org.br>
Differential Revision: https://reviews.freebsd.org/D23382
Per the University California Regents letter, drop the so-called
"advertisement" clause.
Discussed with: bde, kargl (2017)
Differential Revision: https://reviews.freebsd.org/D22928
