Commit Graph

941 Commits

Author SHA1 Message Date
Alex Richardson
f5542795b9 s_scalbn.c: Add missing float.h include
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
2021-03-01 14:22:47 +00:00
Alex Richardson
760b2ffc55 Update scalbn* functions to the musl versions
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
2021-03-01 12:53:45 +00:00
Dimitry Andric
cf97d2a1da Build lib/msun tests with compiler builtins disabled
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
2021-02-23 21:10:01 +01:00
Alex Richardson
f3f7b0dc06 lib/msun/ctrig_test: Print the mismatched values on failure
This test fails on aarch64 but debugging it is difficult without the
results being printed.

Now the failing AArch64 test prints:
root@freebsd-aarch64:/nfsroot/usr/tests/lib/msun # kyua debug ctrig_test:test_nan_inputs
*** Check failed: /local/scratch/alr48/cheri/freebsd/lib/msun/tests/ctrig_test.c:211: (ctan)(_d) (0 + -1 I) != expected (-0 + -1 I)
*** Check failed: /local/scratch/alr48/cheri/freebsd/lib/msun/tests/ctrig_test.c:211: ctan fetestexcept((0x00000002 | 0x00000010 | 0x00000001 | 0x00000004 | 0x00000008)) (0x10) != 0
*** Check failed: /local/scratch/alr48/cheri/freebsd/lib/msun/tests/ctrig_test.c:211: (ctan)(_d) (0 + 1 I) != expected (-0 + 1 I)
*** Check failed: /local/scratch/alr48/cheri/freebsd/lib/msun/tests/ctrig_test.c:211: ctan fetestexcept((0x00000002 | 0x00000010 | 0x00000001 | 0x00000004 | 0x00000008)) (0x10) != 0
*** Check failed: /local/scratch/alr48/cheri/freebsd/lib/msun/tests/ctrig_test.c:211: (ctanf)(_d) (0 + -1 I) != expected (-0 + -1 I)
*** Check failed: /local/scratch/alr48/cheri/freebsd/lib/msun/tests/ctrig_test.c:211: ctanf fetestexcept((0x00000002 | 0x00000010 | 0x00000001 | 0x00000004 | 0x00000008)) (0x10) != 0
*** Check failed: /local/scratch/alr48/cheri/freebsd/lib/msun/tests/ctrig_test.c:211: (ctanf)(_d) (0 + 1 I) != expected (-0 + 1 I)
*** Check failed: /local/scratch/alr48/cheri/freebsd/lib/msun/tests/ctrig_test.c:211: ctanf fetestexcept((0x00000002 | 0x00000010 | 0x00000001 | 0x00000004 | 0x00000008)) (0x10) != 0
*** Check failed: /local/scratch/alr48/cheri/freebsd/lib/msun/tests/ctrig_test.c:217: (ctanh)(_d) (1 + 0 I) != expected (1 + -0 I)
*** Check failed: /local/scratch/alr48/cheri/freebsd/lib/msun/tests/ctrig_test.c:217: ctanh fetestexcept((0x00000002 | 0x00000010 | 0x00000001 | 0x00000004 | 0x00000008)) (0x10) != 0
*** Check failed: /local/scratch/alr48/cheri/freebsd/lib/msun/tests/ctrig_test.c:217: (ctanhf)(_d) (1 + 0 I) != expected (1 + -0 I)
*** Check failed: /local/scratch/alr48/cheri/freebsd/lib/msun/tests/ctrig_test.c:217: ctanhf fetestexcept((0x00000002 | 0x00000010 | 0x00000001 | 0x00000004 | 0x00000008)) (0x10) != 0
*** Check failed: /local/scratch/alr48/cheri/freebsd/lib/msun/tests/ctrig_test.c:217: (ctanh)(_d) (-1 + 0 I) != expected (-1 + -0 I)
*** Check failed: /local/scratch/alr48/cheri/freebsd/lib/msun/tests/ctrig_test.c:217: ctanh fetestexcept((0x00000002 | 0x00000010 | 0x00000001 | 0x00000004 | 0x00000008)) (0x10) != 0
*** Check failed: /local/scratch/alr48/cheri/freebsd/lib/msun/tests/ctrig_test.c:217: (ctanhf)(_d) (-1 + 0 I) != expected (-1 + -0 I)
*** Check failed: /local/scratch/alr48/cheri/freebsd/lib/msun/tests/ctrig_test.c:217: ctanhf fetestexcept((0x00000002 | 0x00000010 | 0x00000001 | 0x00000004 | 0x00000008)) (0x10) != 0
ctrig_test:test_nan_inputs  ->  failed: 16 checks failed; see output for more details

Reviewed By:	ngie
Differential Revision: https://reviews.freebsd.org/D28788
2021-02-23 09:39:40 +00:00
Alex Richardson
1ec3feb648 Update libm tests from NetBSD
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
2021-02-22 17:41:04 +00:00
Alex Richardson
a7b42c4b7f msun: ctanh/ctanhf: Import fix from musl libc
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
2021-02-15 22:55:12 +00:00
Dimitry Andric
d3338f3355 Fix incorrect hypotl(3) result with subnormal numbers
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
2021-02-10 23:28:43 +01:00
Dimitry Andric
ac76bc1145 Fix lib/msun's ctrig_test/test_inf_inputs test case with clang >= 10
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
2021-02-09 22:07:05 +01:00
Steve Kargl
93fc678965 Fix incorrect powf(3) result with x near 1 and |y| much larger than 1
This adjusts the check to trigger overflow/underflow to a slightly lower
value.

Before: powf(9.999995e-01, -1.342177e+08) -> inf
After:  powf(9.999995e-01, -1.342177e+08) -> 1.858724e+31

MFC after:	1 week
2021-02-08 20:48:43 +01:00
Alex Richardson
892a05ee3a Avoid double output in fenv_test
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
2021-01-29 09:29:27 +00:00
Alex Richardson
4d2edf3af1 test_inf_inputs: Use atf_tc_expect_fail() instead of atf_tc_skip()
Reviewed By:	lwhsu
Differential Revision: https://reviews.freebsd.org/D28396
2021-01-29 09:28:40 +00:00
Alex Richardson
d4a6843bb1 Update comment missed in 83ff5d5d98
Reported by:	jrtc27
2021-01-29 09:19:27 +00:00
Alex Richardson
83ff5d5d98 Un-XFAIL two tests with Clang > 10
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
2021-01-28 17:24:24 +00:00
Conrad Meyer
78599c32ef Add CFI start/end proc directives to arm64, i386, and ppc
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
2020-12-05 00:33:28 +00:00
Alfredo Dal'Ava Junior
758f9acf8c msun tests: use standard floating-point exception flags on lrint and fenv tests
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
2020-11-18 19:23:30 +00:00
Alfredo Dal'Ava Junior
e7bd4f846f [POWERPC] msun: fix incorrect flag in fesetexceptflag
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
2020-11-17 12:36:59 +00:00
Warner Losh
e369c79ca0 Remove intel compiler support from math.h
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.
2020-10-24 23:21:22 +00:00
Gordon Bergling
3d265fce43 Fix a few mandoc issues
- skipping paragraph macro: Pp after Sh
- sections out of conventional order: Sh EXAMPLES
- whitespace at end of input line
- normalizing date format
2020-10-09 19:12:44 +00:00
Stefan Eßer
fcce470c2b Apply an opimization for the kernels used by cexp(x) and cexpf(x) submitted
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)
2020-09-20 05:32:53 +00:00
Stefan Eßer
a67cc94327 Apply fix for ld80 and ld128 submitted by 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)
2020-09-20 05:28:31 +00:00
Xin LI
941791759c Don't explicitly specify c99 or gnu99 as the default is now gnu99.
MFC after:	2 weeks
2020-08-17 05:57:02 +00:00
Mitchell Horne
2d143336de Enable long double tests on RISC-V
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
2020-06-24 13:11:19 +00:00
Eric van Gyzen
fac6dee9eb Remove tests for obsolete compilers in the build system
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
2020-05-12 15:22:40 +00:00
Sergio Carlavilla Delgado
d2034aedc1 Fix typo 2020-04-04 07:43:47 +00:00
Warner Losh
5310132318 Note some functions that appeared in First Edition Unix
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.
2020-04-01 22:50:41 +00:00
Alfredo Dal'Ava Junior
f1343c7f67 msun: swap words order instead of bits order on BIG ENDIAN
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
2020-03-26 18:50:54 +00:00
Sergio Carlavilla Delgado
8e76d7909d Add HISTORY sections to log(3) man page
PR:		240265
Submitted by:	gbergling@gmail.com
Approved by:	bcr@(mentor), imp@
MFC after:	1 day
Differential Revision:	https://reviews.freebsd.org/D24148
2020-03-26 11:24:43 +00:00
Li-Wen Hsu
0fc06121ac Temporarily skip 2 failing tests after llvm10 import
PR:		244732
Sponsored by:	The FreeBSD Foundation
2020-03-11 12:43:54 +00:00
Warner Losh
a8197ad3aa Remove sparc64 specific parts of libm and fix comments
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
2020-02-26 18:55:03 +00:00
Sergio Carlavilla Delgado
8209febbb3 Add some HISTORY sections to manpages
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
2020-02-19 12:49:49 +00:00
Brandon Bergren
469026a8a3 [PowerPC] Fix feholdexcept() on powerpc referencing the wrong struct member
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
2020-02-02 19:16:52 +00:00
Pedro F. Giffuni
afced35c1d msun: drop clause 3 from the Berkeley license.
Per the University California Regents letter, drop the so-called
"advertisement" clause.

Discussed with:	bde, kargl (2017)
Differential Revision:	https://reviews.freebsd.org/D22928
2019-12-27 01:11:26 +00:00
Brandon Bergren
4f9ed3156c [PowerPC] Fix SPE floating point environment manipulation
Fix multiple problems in the powerpcspe floating point code.

* Endianness handling of the SPEFSCR in fenv.h was completely broken.
* Ensure SPEFSCR synchronization requirements are being met.

The __r.__d -> __r transformations were written by jhibbits.

Reviewed by:	jhibbits
Differential Revision:	https://reviews.freebsd.org/D22526
2019-12-12 17:12:18 +00:00
Simon J. Gerraty
2c9a9dfc18 Update Makefile.depend files
Update a bunch of Makefile.depend files as
a result of adding Makefile.depend.options files

Reviewed by:	 bdrewery
MFC after:	1 week
Sponsored by:   Juniper Networks
Differential Revision:  https://reviews.freebsd.org/D22494
2019-12-11 17:37:53 +00:00
Dimitry Andric
83fa0a287f The fdlibm hypot() implementations shouldn't potentially left-shift
negative numbers (invoking undefined behavior)

Summary:
Various paths through hypot(x, y) will multiply x and y by a power of
two, perform the calculation in a range where IEEE-754 provides greater
precision, then undo the multiplication to determine the true result.
Undoing that multiplication is implemented as t1*w, where t1=2**k.

2**k is often computed by taking the high word of 1.0, then adding k<<20
(for doubles or long doubles) or k<<23 (for floats) to it, then
overwriting that high word. But when k is negative this left-shifts a
negative value -- and that's undefined behavior in many editions of C
and C++.

This patch should fix all hypot implementations to compute 2**k without
triggering this particular bit of undefined behavior.

Test Plan: I've only very lightly tested out the hypot(double, double)
change, in SpiderMonkey's JavaScript engine, for consistency with prior
behavior.  The other functions' changes have more or less only been
eyeballed.  Careful examination appreciated!  Do note, however, that an
error in any of these changes would most likely produce a value that is
incorrect by a factor of two, so any mistake would most likely be
glaring if invoked.

Submitted by:	Jeff Walden <jwalden@mit.edu>
Obtained from:	https://github.com/freebsd/freebsd/pull/414
Reviewed by:	dim, lwhsu
MFC after:	1 week
Differential Revision: https://reviews.freebsd.org/D22354
2019-11-26 22:01:09 +00:00
Li-Wen Hsu
12c4ab4377 Get the fix in back by reverting the part accidentally included in r354491.
This brings back r354467.

MFC after:	1 week
Sponsored by:	The FreeBSD Foundation
2019-11-07 23:57:48 +00:00
Brooks Davis
a4330302f2 libcompat: build 32-bit rtld and ldd as part of "everything"
Alter bsd.compat.mk to set MACHINE and MACHINE_ARCH when included
directly so MD paths in Makefiles work. In the process centralize
setting them in LIBCOMPATWMAKEENV.

Alter .PATH and CFLAGS settings in work when the Makefile is included.

While here only support LIB32 on supported platforms rather than always
enabling it and requiring users of MK_LIB32 to filter based
TARGET/MACHINE_ARCH.

The net effect of this change is to make Makefile.libcompat only build
compatability libraries.

Changes relative to r354449:

Correct detection of the compiler type when bsd.compat.mk is used
outside Makefile.libcompat.  Previously it always matched the clang
case.

Set LDFLAGS including the linker emulation for mips where -m32 seems to
be insufficent.

Reviewed by:	imp, kib (origional version in r354449)
Obtained from:	CheriBSD (conceptually)
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D22251
2019-11-07 22:58:10 +00:00
Brooks Davis
271d2989ba Fix declaration of S1 by swapping misplaced ',' and ';'.
Reported by:	kargl
Obtained from:	OpenBSD (tb@openbsd.org)
MFC after:	1 week
2019-11-07 19:31:56 +00:00
Brooks Davis
1edbf0e9ba Revert change accidentally included in r354465.
Will recommit with a proper commit message shortly.
2019-11-07 19:28:03 +00:00
Brooks Davis
ccad77fe1e Revert r354449: libcompat: build 32-bit rtld and ldd as part of "everything"
Additional testing is required..
2019-11-07 19:22:51 +00:00
Dimitry Andric
f68ff1ac1c Add __isnan()/__isnanf() aliases for compatibility with glibc and CUDA
Even though clang comes with a number of internal CUDA wrapper headers,
compiling sample CUDA programs will result in errors similar to:

In file included from <built-in>:1:
In file included from /usr/lib/clang/9.0.0/include/__clang_cuda_runtime_wrapper.h:204:
/usr/home/arr/cuda/var/cuda-repo-10-0-local-10.0.130-410.48/usr/local/cuda-10.0//include/crt/math_functions.hpp:2910:7: error: no matching function for call to '__isnan'
  if (__isnan(a)) {
      ^~~~~~~
/usr/lib/clang/9.0.0/include/__clang_cuda_device_functions.h:460:16: note: candidate function not viable: call to __device__ function from __host__ function
__DEVICE__ int __isnan(double __a) { return __nv_isnand(__a); }
               ^

CUDA expects __isnan() and __isnanf() declarations to be available,
which are glibc specific extensions, equivalent to the regular isnan()
and isnanf().

To provide these, define __isnan() and __isnanf() as aliases of the
already existing static inline functions __inline_isnan() and
__inline_isnanf() from math.h.

Reported by:	arrowd
PR:		241550
MFC after:	1 week
2019-11-02 16:59:53 +00:00
Conrad Meyer
168f19a57b libm: Add missing END() directives for amd64 routines
No functional change.  Related to D22122.

Reviewed by:	emaste, kib (earlier version both)
2019-10-23 16:05:52 +00:00
Brooks Davis
e593620997 msun: Silence new harmless -Wimplicit-int-float-conversion warnings
Clang from trunk recently added a warning for when implicit int-to-float
conversions cause a loss of precision. The code in question is designed
to be able to handle that, so add explicit casts to silence this.

Submitted by:	James Clarke <jrtc27@jrtc27.com>
Reviewed by:	dim
Obtained from:	CheriBSD
MFC after:	1 week
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D21913
2019-10-08 21:39:51 +00:00
Dimitry Andric
5763a8cf06 Do not left-shift a negative number (inducing undefined behavior in
C/C++) in exp(3), expf(3), expm1(3) and expm1f(3) during intermediate
computations that compute the IEEE-754 bit pattern for |2**k| for
integer |k|.

The implementations of exp(3), expf(3), expm1(3) and expm1f(3) need to
compute IEEE-754 bit patterns for 2**k in certain places.  (k is an
integer and 2**k is exactly representable in IEEE-754.)

Currently they do things like 0x3FF0'0000+(k<<20), which is to say they
take the bit pattern representing 1 and then add directly to the
exponent field to get the desired power of two.  This is fine when k is
non-negative.

But when k<0 (and certain classes of input trigger this), this
left-shifts a negative number -- an operation with undefined behavior in
C and C++.

The desired semantics can be achieved by instead adding the
possibly-negative k to the IEEE-754 exponent bias to get the desired
exponent field, _then_ shifting that into its proper overall position.

(Note that in case of s_expm1.c and s_expm1f.c, there are SET_HIGH_WORD
and SET_FLOAT_WORD uses further down in each of these files that perform
shift operations involving k, but by these points k's range has been
restricted to 2 < k <= 56, and the shift operations under those
circumstances can't do anything that would be UB.)

Submitted by:	Jeff Walden, https://github.com/jswalden
Obtained from:	https://github.com/freebsd/freebsd/pull/411
Obtained from:	https://github.com/freebsd/freebsd/pull/412
MFC after:	3 days
2019-09-25 18:50:57 +00:00
Li-Wen Hsu
24612bfd1f Unskip test cases from netbsd-tests by defining __HAVE_FENV
This unskips:
  - lib.libc.stdlib.strtod_test.strtod_round
  - lib.msun.fe_round_test.t_nofe_round

In lib/msun/tests/Makefile only define on fe_round_test.c because
lib.msun.ilogb_test.ilogb will get wrong results and needs more examination.

MFC after:	1 week
Sponsored by:	The FreeBSD Foundation
2019-08-31 20:45:45 +00:00
Edward Tomasz Napierala
5a38af1fb8 Introduce <sys/qmath.h>, a fixed-point math library from Netflix.
This makes it possible to perform mathematical operations
on
fractional values without using floating point. It operates on Q
numbers, which are integer-sized, opaque structures initialized
to hold a chosen number of integer and fractional
bits.


For a general description of the Q number system, see the "Fixed Point
Representation & Fractional Math" whitepaper[1]; for the actual
API see the qmath(3) man page.

This is one of dependencies for the upcoming stats(3) framework[2]
that will be applied to the TCP stack in a later commit.

1. https://www.superkits.net/whitepapers/Fixed%20Point%20Representation%20&%20Fractional%20Math.pdf
2. https://reviews.freebsd.org/D20477

Reviewed by:	bcr (man pages, earlier version), sef (earlier version)
Discussed with:	cem, dteske, imp, lstewart
Sponsored By:	Klara Inc, Netflix
Obtained from:	Netflix
Differential Revision:	https://reviews.freebsd.org/D20116
2019-08-27 11:46:22 +00:00
Dimitry Andric
740890be23 Partially revert r271349, which disabled the msun cexp test #4 on i386.
Ensure the expected result is stored first in a volatile variable with
the desired type.  This makes all the tests succeed.

Slightly changed from the original pull request, but functionally the
same.

Obtained from:	https://github.com/freebsd/freebsd/pull/401
Submitted by:	Moritz Buhl <gh@moritzbuhl.de>
PR:		191676
MFC after:	3 days
2019-06-01 20:08:10 +00:00
Peter Jeremy
885bfcda11 Replace calls to sin(x) and cos(x) with a single call to sincos().
Replace calls to sinf(x) and cosf(x) with a single call to sincosf().

Submitted by:	Steve Kargl <sgk@troutmask.apl.washington.edu>
Reviewed by:	bde
Approved by:	grog
MFC after:	3 days
2019-02-10 08:46:07 +00:00
Dimitry Andric
bc8fc00705 Amend r343442, by only expecting the lib.msun.cbrt_test.cbrtl_powl and
trig_test.reduction test cases to fail, if the fixes from r343916 have
not yet been applied to the base compiler.

Reported by:    lwhsu
PR:		234040
Upstream PR:	https://bugs.llvm.org/show_bug.cgi?id=40206
MFC after:	1 week
2019-02-08 18:31:54 +00:00
Eric van Gyzen
50b06886a7 libm: squelch -Woverflow from gcc6
Sponsored by:	Dell EMC Isilon
2019-02-01 23:15:54 +00:00