Cygwin: trunc(2.75) is broken somewhere on long double builds

[p5pRT]

Migrated from rt.perl.org#128665 (status was 'open')

Searchable as RT128665$

[p5pRT]

From @dcollinsn

Hello!

I'm seeing the following test failure on Cygwin long double builds. Threads are not required, building with the following is adequate​:

./Configure -Dusedevel -des -Duselongdouble -Accflags=-D_GNU_SOURCE -Alibswanted=cygwin && make test_prep

The two -A on the Configure line are workarounds to RT #128358 and RT #128637

dcollins@​DESKTOP-ER38TCQ ~/perlstable
$ ./perl -Ilib
use strict;

use POSIX '​:math_h_c99';
use POSIX '​:nan_payload';
use Test​::More;

is(trunc(2.25), 2, "trunc 2.25");
is(trunc(-2.25), -2, "trunc -2.25");
is(trunc(2.5), 2, "trunc 2.5");
is(trunc(-2.5), -2, "trunc -2.5");
is(trunc(2.75), 2, "trunc 2.75");
is(trunc(-2.75), -2, "trunc -2.75");
is(getpayload(nan(1234.567)), 1234, "nan (trunc) + getpayload");
ok 1 - trunc 2.25
ok 2 - trunc -2.25
ok 3 - trunc 2.5
ok 4 - trunc -2.5
not ok 5 - trunc 2.75
# Failed test 'trunc 2.75'
# at - line 11.
# got​: '3'
# expected​: '2'
not ok 6 - trunc -2.75
# Failed test 'trunc -2.75'
# at - line 12.
# got​: '-3'
# expected​: '-2'
not ok 7 - nan (trunc) + getpayload
# Failed test 'nan (trunc) + getpayload'
# at - line 13.
# got​: '1235'
# expected​: '1234'
# Tests were run but no plan was declared and done_testing() was not seen.

dcollins@​DESKTOP-ER38TCQ ~/perlstable
$ ./perl -Ilib -V
Summary of my perl5 (revision 5 version 25 subversion 2) configuration​:
  Commit id​: 8c47236
  Platform​:
  osname=cygwin, osvers=2.5.1(0.29753), archname=cygwin-thread-multi-ld
  uname='cygwin_nt-10.0 desktop-er38tcq 2.5.1(0.29753) 2016-04-21 22​:14 x86_64 cygwin '
  config_args='-Dusedevel -des -Doptimize=-O3 -g -Dusethreads -Duselongdouble -Accflags=-D_GNU_SOURCE -Alibswanted=cygwin'
  hint=recommended, useposix=true, d_sigaction=define
  useithreads=define, usemultiplicity=define
  use64bitint=define, use64bitall=define, uselongdouble=define
  usemymalloc=n, bincompat5005=undef
  Compiler​:
  cc='gcc', ccflags ='-DPERL_USE_SAFE_PUTENV -U__STRICT_ANSI__ -D_GNU_SOURCE -fwrapv -fno-strict-aliasing -pipe -fstack-protector-strong -D_FORTIFY_SOURCE=2',
  optimize='-O3 -g',
  cppflags='-DPERL_USE_SAFE_PUTENV -U__STRICT_ANSI__ -D_GNU_SOURCE -fwrapv -fno-strict-aliasing -pipe -fstack-protector-strong'
  ccversion='', gccversion='5.3.0', gccosandvers=''
  intsize=4, longsize=8, ptrsize=8, doublesize=8, byteorder=12345678, doublekind=3
  d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=16, longdblkind=3
  ivtype='long', ivsize=8, nvtype='long double', nvsize=16, Off_t='off_t', lseeksize=8
  alignbytes=16, prototype=define
  Linker and Libraries​:
  ld='g++', ldflags =' -Wl,--enable-auto-import -Wl,--export-all-symbols -Wl,--enable-auto-image-base -fstack-protector-strong -L/usr/local/lib'
  libpth=/usr/lib /usr/lib/../lib/../include/w32api /usr/local/lib /lib
  libs=-lpthread -ldl -lcygwin
  perllibs=-lpthread -ldl -lcygwin
  libc=/usr/lib/libc.a, so=dll, useshrplib=true, libperl=cygperl5_25_2.dll
  gnulibc_version=''
  Dynamic Linking​:
  dlsrc=dl_dlopen.xs, dlext=dll, d_dlsymun=undef, ccdlflags=' '
  cccdlflags=' ', lddlflags=' --shared -Wl,--enable-auto-import -Wl,--export-all-symbols -Wl,--enable-auto-image-base -L/usr/local/lib -fstack-protector-strong'

Characteristics of this binary (from libperl)​:
  Compile-time options​: HAS_TIMES MULTIPLICITY PERLIO_LAYERS
  PERL_COPY_ON_WRITE PERL_DONT_CREATE_GVSV
  PERL_HASH_FUNC_ONE_AT_A_TIME_HARD
  PERL_IMPLICIT_CONTEXT PERL_MALLOC_WRAP PERL_OP_PARENT
  PERL_PRESERVE_IVUV PERL_USE_DEVEL
  PERL_USE_SAFE_PUTENV USE_64_BIT_ALL USE_64_BIT_INT
  USE_ITHREADS USE_LARGE_FILES USE_LOCALE
  USE_LOCALE_COLLATE USE_LOCALE_CTYPE
  USE_LOCALE_NUMERIC USE_LOCALE_TIME USE_LONG_DOUBLE
  USE_PERLIO USE_PERL_ATOF USE_REENTRANT_API
  Built under cygwin
  Compiled at Jul 18 2016 13​:14​:50
  @​INC​:
  lib
  /usr/local/lib/perl5/site_perl/5.25.2/cygwin-thread-multi-ld
  /usr/local/lib/perl5/site_perl/5.25.2
  /usr/local/lib/perl5/5.25.2/cygwin-thread-multi-ld
  /usr/local/lib/perl5/5.25.2
  /usr/local/lib/perl5/site_perl
  .

--
Respectfully,
Dan Collins

[p5pRT]

From @dcollinsn

In particular, trunc() seems to be using round towards nearest, ties to
even, rather than round towards zero.

On Mon, Jul 18, 2016 at 1​:34 PM, Dan Collins <perlbug-followup@​perl.org>
wrote​:

# New Ticket Created by Dan Collins
# Please include the string​: [perl #128665]
# in the subject line of all future correspondence about this issue.
# <URL​: https://rt-archive.perl.org/perl5/Ticket/Display.html?id=128665 >

Hello!

I'm seeing the following test failure on Cygwin long double builds.
Threads are not required, building with the following is adequate​:

./Configure -Dusedevel -des -Duselongdouble -Accflags=-D_GNU_SOURCE
-Alibswanted=cygwin && make test_prep

The two -A on the Configure line are workarounds to RT #128358 and RT
#128637

dcollins@​DESKTOP-ER38TCQ ~/perlstable
$ ./perl -Ilib
use strict;

use POSIX '​:math_h_c99';
use POSIX '​:nan_payload';
use Test​::More;

is(trunc(2.25), 2, "trunc 2.25");
is(trunc(-2.25), -2, "trunc -2.25");
is(trunc(2.5), 2, "trunc 2.5");
is(trunc(-2.5), -2, "trunc -2.5");
is(trunc(2.75), 2, "trunc 2.75");
is(trunc(-2.75), -2, "trunc -2.75");
is(getpayload(nan(1234.567)), 1234, "nan (trunc) + getpayload");
ok 1 - trunc 2.25
ok 2 - trunc -2.25
ok 3 - trunc 2.5
ok 4 - trunc -2.5
not ok 5 - trunc 2.75
# Failed test 'trunc 2.75'
# at - line 11.
# got​: '3'
# expected​: '2'
not ok 6 - trunc -2.75
# Failed test 'trunc -2.75'
# at - line 12.
# got​: '-3'
# expected​: '-2'
not ok 7 - nan (trunc) + getpayload
# Failed test 'nan (trunc) + getpayload'
# at - line 13.
# got​: '1235'
# expected​: '1234'
# Tests were run but no plan was declared and done_testing() was not seen.

dcollins@​DESKTOP-ER38TCQ ~/perlstable
$ ./perl -Ilib -V
Summary of my perl5 (revision 5 version 25 subversion 2) configuration​:
Commit id​: 8c47236
Platform​:
osname=cygwin, osvers=2.5.1(0.29753), archname=cygwin-thread-multi-ld
uname='cygwin_nt-10.0 desktop-er38tcq 2.5.1(0.29753) 2016-04-21 22​:14
x86_64 cygwin '
config_args='-Dusedevel -des -Doptimize=-O3 -g -Dusethreads
-Duselongdouble -Accflags=-D_GNU_SOURCE -Alibswanted=cygwin'
hint=recommended, useposix=true, d_sigaction=define
useithreads=define, usemultiplicity=define
use64bitint=define, use64bitall=define, uselongdouble=define
usemymalloc=n, bincompat5005=undef
Compiler​:
cc='gcc', ccflags ='-DPERL_USE_SAFE_PUTENV -U__STRICT_ANSI__
-D_GNU_SOURCE -fwrapv -fno-strict-aliasing -pipe -fstack-protector-strong
-D_FORTIFY_SOURCE=2',
optimize='-O3 -g',
cppflags='-DPERL_USE_SAFE_PUTENV -U__STRICT_ANSI__ -D_GNU_SOURCE
-fwrapv -fno-strict-aliasing -pipe -fstack-protector-strong'
ccversion='', gccversion='5.3.0', gccosandvers=''
intsize=4, longsize=8, ptrsize=8, doublesize=8, byteorder=12345678,
doublekind=3
d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=16,
longdblkind=3
ivtype='long', ivsize=8, nvtype='long double', nvsize=16,
Off_t='off_t', lseeksize=8
alignbytes=16, prototype=define
Linker and Libraries​:
ld='g++', ldflags =' -Wl,--enable-auto-import -Wl,--export-all-symbols
-Wl,--enable-auto-image-base -fstack-protector-strong -L/usr/local/lib'
libpth=/usr/lib /usr/lib/../lib/../include/w32api /usr/local/lib /lib
libs=-lpthread -ldl -lcygwin
perllibs=-lpthread -ldl -lcygwin
libc=/usr/lib/libc.a, so=dll, useshrplib=true,
libperl=cygperl5_25_2.dll
gnulibc_version=''
Dynamic Linking​:
dlsrc=dl_dlopen.xs, dlext=dll, d_dlsymun=undef, ccdlflags=' '
cccdlflags=' ', lddlflags=' --shared -Wl,--enable-auto-import
-Wl,--export-all-symbols -Wl,--enable-auto-image-base -L/usr/local/lib
-fstack-protector-strong'

Characteristics of this binary (from libperl)​:
Compile-time options​: HAS_TIMES MULTIPLICITY PERLIO_LAYERS
PERL_COPY_ON_WRITE PERL_DONT_CREATE_GVSV
PERL_HASH_FUNC_ONE_AT_A_TIME_HARD
PERL_IMPLICIT_CONTEXT PERL_MALLOC_WRAP
PERL_OP_PARENT
PERL_PRESERVE_IVUV PERL_USE_DEVEL
PERL_USE_SAFE_PUTENV USE_64_BIT_ALL USE_64_BIT_INT
USE_ITHREADS USE_LARGE_FILES USE_LOCALE
USE_LOCALE_COLLATE USE_LOCALE_CTYPE
USE_LOCALE_NUMERIC USE_LOCALE_TIME USE_LONG_DOUBLE
USE_PERLIO USE_PERL_ATOF USE_REENTRANT_API
Built under cygwin
Compiled at Jul 18 2016 13​:14​:50
@​INC​:
lib
/usr/local/lib/perl5/site_perl/5.25.2/cygwin-thread-multi-ld
/usr/local/lib/perl5/site_perl/5.25.2
/usr/local/lib/perl5/5.25.2/cygwin-thread-multi-ld
/usr/local/lib/perl5/5.25.2
/usr/local/lib/perl5/site_perl
.

--
Respectfully,
Dan Collins

[p5pRT]

From Stromeko@nexgo.de

Dan Collins writes​:

In particular, trunc() seems to be using round towards nearest, ties to
even, rather than round towards zero.

This seems to be a bug in Cygwin. The code in question was imported
from MinGW-64, so it might have the same problem there.

Regards,
Achim.
--
+<[Q+ Matrix-12 WAVE#46+305 Neuron microQkb Andromeda XTk Blofeld]>+

DIY Stuff​:
http​://Synth.Stromeko.net/DIY.html

[p5pRT]

The RT System itself - Status changed from 'new' to 'open'

[p5pRT]

From @dcollinsn

On Mon Jul 18 12​:43​:19 2016, Stromeko@​nexgo.de wrote​:

Dan Collins writes​:

In particular, trunc() seems to be using round towards nearest, ties to
even, rather than round towards zero.

This seems to be a bug in Cygwin. The code in question was imported
from MinGW-64, so it might have the same problem there.

Regards,
Achim.

Maybe. MinGW-w64 x86_64 builds have this entire test program (ext/POSIX/t/math.t) failing after test 28 in my build logs, so I'll have to look a bit more closely once I have that computer in front of me.

--
Respectfully,
Dan Collins

[p5pRT]

From Stromeko@nexgo.de

Dan Collins via RT writes​:

Maybe. MinGW-w64 x86_64 builds have this entire test program
(ext/POSIX/t/math.t) failing after test 28 in my build logs, so I'll
have to look a bit more closely once I have that computer in front of
me.

It was a bug in Cygwin that only affected truncl by sheer luck. Will be
fixed in the next release.

Regards,
Achim.
--
+<[Q+ Matrix-12 WAVE#46+305 Neuron microQkb Andromeda XTk Blofeld]>+

Factory and User Sound Singles for Waldorf Q+, Q and microQ​:
http​://Synth.Stromeko.net/Downloads.html#WaldorfSounds

[p5pRT]

From @dcollinsn

On Mon Jul 18 12​:57​:18 2016, Stromeko@​nexgo.de wrote​:

Dan Collins via RT writes​:

Maybe. MinGW-w64 x86_64 builds have this entire test program
(ext/POSIX/t/math.t) failing after test 28 in my build logs, so I'll
have to look a bit more closely once I have that computer in front of
me.

It was a bug in Cygwin that only affected truncl by sheer luck. Will be
fixed in the next release.

Regards,
Achim.

Glad to hear it.

Porters​: my current builds of perl using the MinGW-w64 compilers are not affected, this is cygwin only.

--
Respectfully,
Dan Collins