bug#14789: BUG: Modules compile as ELF's on PE/PE+ architecture

[Vasiliy]

Hi, Mark,

Sorry for my previous double-posting to the guile-devel maillist; just
at that time I didn't have a reply from guile-bugs'.

I've run ./check-guile numbers.test, yes, it hasn't been invoked my
"make check" from the top-level build directory. For the latest Guile
compiled with CFLAGS="-mtune=native -march=native -O2" I've got the
following:

$ ./check-guile numbers.test
Testing /usr/src/64bit/release/guile/guile-2.1.0-57/build/meta/guile
... numbers.test
with 
GUILE_LOAD_PATH=/usr/src/64bit/release/guile/guile-2.1.0-57/src/guile-2.1.0/test-suite
Running numbers.test
FAIL: numbers.test: inexact->exact: smallest inexact: pos - arguments:
(expected-value
1/202402253307310618352495346718917307049556649764142118356901358027430339567995346891960383701437124495187077864316811911389808737385793476867013399940738509921517424276566361364466907742093216341239767678472745068562007483424692698618103355649159556340810056512358769552333414615230502532186327508646006263307707741093494784
actual-value 0)
FAIL: numbers.test: inexact->exact: smallest inexact: neg - arguments:
(expected-value
-1/202402253307310618352495346718917307049556649764142118356901358027430339567995346891960383701437124495187077864316811911389808737385793476867013399940738509921517424276566361364466907742093216341239767678472745068562007483424692698618103355649159556340810056512358769552333414615230502532186327508646006263307707741093494784
actual-value 0)
FAIL: numbers.test: inexact->exact: smallest inexact * 2: pos -
arguments: (expected-value
1/101201126653655309176247673359458653524778324882071059178450679013715169783997673445980191850718562247593538932158405955694904368692896738433506699970369254960758712138283180682233453871046608170619883839236372534281003741712346349309051677824579778170405028256179384776166707307615251266093163754323003131653853870546747392
actual-value 0)
FAIL: numbers.test: inexact->exact: smallest inexact * 2: neg -
arguments: (expected-value
-1/101201126653655309176247673359458653524778324882071059178450679013715169783997673445980191850718562247593538932158405955694904368692896738433506699970369254960758712138283180682233453871046608170619883839236372534281003741712346349309051677824579778170405028256179384776166707307615251266093163754323003131653853870546747392
actual-value 0)
FAIL: numbers.test: inexact->exact: smallest inexact * 3: pos -
arguments: (expected-value
3/202402253307310618352495346718917307049556649764142118356901358027430339567995346891960383701437124495187077864316811911389808737385793476867013399940738509921517424276566361364466907742093216341239767678472745068562007483424692698618103355649159556340810056512358769552333414615230502532186327508646006263307707741093494784
actual-value 0)
FAIL: numbers.test: inexact->exact: smallest inexact * 3: neg -
arguments: (expected-value
-3/202402253307310618352495346718917307049556649764142118356901358027430339567995346891960383701437124495187077864316811911389808737385793476867013399940738509921517424276566361364466907742093216341239767678472745068562007483424692698618103355649159556340810056512358769552333414615230502532186327508646006263307707741093494784
actual-value 0)

Totals for this test run:
passes:                 28367
failures:               6
unexpected passes:      0
expected failures:      0
unresolved test cases:  0
untested test cases:    0
unsupported test cases: 0
errors:                 0

Regards,
Vasiliy

On Sat, Jul 6, 2013 at 9:09 PM, Mark H Weaver <address@hidden> wrote:
> Vasiliy <address@hidden> writes:
>
>> It's just to highlight I've got that error of:
>> fail: scm_from_double (1) == +nan.0
>> FAIL: test-conversion.exe
>>
>> while compiling with:
>> CFLAGS="-mtune=native -march=native -Ofast -fomit-frame-pointer"
>
> I now see the problem.  -Ofast implies -ffast-math, which implies
> -funsafe-math-optimizations, -ffinite-math-only, etc.  Specifically,
> this enabled the compiler to optimize (guile_Inf / guile_Inf) to 1.0,
> which foiled Guile's attempt to create a NaN object.
>
> From the GCC manual (Optimize Options):
>
> `-Ofast'
>      Disregard strict standards compliance.  `-Ofast' enables all `-O3'
>      optimizations.  It also enables optimizations that are not valid
>      for all standard compliant programs.  It turns on `-ffast-math'
>      and the Fortran-specific `-fno-protect-parens' and
>      `-fstack-arrays'.
>
> My recommendation would be to avoid -Ofast, not just in Guile but in
> general.  It is likely to create subtle problems in a lot of software.
>
> Things like language interpreters in particular tend to push the
> boundaries of standards compliance, and are likely to be broken in
> subtle ways by -Ofast.
>
> It's reasonable and sometimes useful to use -Ofast in isolated modules
> containing hot code, but only in modules whose -Ofast safety has been
> investigated by someone who understands the associated compiler
> optimizations, and is familiar with the kinds of breakage that can
> occur.
>
>> There's, however, still an error with 'test-ffi', and there's no
>> automatic invocation of 'numbers.test'.
>
> Strange.  Did you run "make check" in the top-level build directory?
>
> If that doesn't work, maybe try: "./check-guile numbers.test"
>
>> Would be there any support for -Ofast in future?
>
> I doubt that we would officially support it.  It's possible that the
> bugs introduced by -Ofast will not affect you, I don't know.  At the
> very least, you are likely to get incorrect answers from the numerics
> library in some cases.  There might be more serious problems as well.
> Some of these problems might be discovered by our test suite, which you
> don't seem to be running most of.  Others might remain undetected.
>
>> Just one point more here: the latest autogen when compiled
>> --with-guile=2.2 refers to 'scm_subr_table' not present in mainstream
>> Guile.
>
> This indicates that you compiled against Guile 1.8's headers.  You'll
> need to arrange to have Guile 2.2's headers come first in the search
> path.  I guess the --with-libguile option to autogen's configure is what
> you need.
>
>      Regards,
>        Mark