boost::simd log exp pow ...

[engelbert...@uantwerpen.be]

Hi all,
i am evaluating NT2 for building HPC applications. I really liked the idea of boost::simd being a header only library. i know the problematic lack of documentation has been raised before, but repeating it does no harm. 

Basically i wrote a few tests which do computations on arrays of 2000 floats (which fit entirely in L1 cache). really simple stuff like
z = x + y
z = x - y
z = x * y
z = x / y
z = sqrt(x) 

using boost::simd::pack<float> for x, y and z
once i took a look at demo/saxpy/simd/saxpy_simd i was able to figure out the right include files and i got things working quickly. however i am stuck on

z = log(x)

z = exp(x)

z = pow(x,y)

none of the include files like .../log.hpp in boost/simd or nt2 etc could make the code compile 

the test code typically looks like:

typedef boost::simd::pack<float> svfloat_t;

size_t const svfloat_width = svfloat_t::static_size;

size_t const ne = 2000;

std::vector<float,boost::simd::allocator<float>> x_(ne);

std::vector<float,boost::simd::allocator<float>> y_(ne);

std::vector<float,boost::simd::allocator<float>> z_(ne);

for( size_t i=0; i<ne; i+=svfloat_width ) {

     svfloat_t sv_x( &x_[i] );       

     svfloat_t sv_y( &y_[i] );       

     boost::simd::aligned_store( OP( sv_x ), &z_[i] );   

}

as said for OP equal to sqrt this went fine, but for log not

os : ubuntu 13.10

compiler : gcc 4.8.1

cpu : ivy-bridge  (AVX support)

any help is wellcome.

[Joel Falcou]

You need to include

nt2/include/functions/log.hpp

as log etc... lives in NT2 and not boost.simd.

If it doesnt solve your issue, we may need to know how you installed the
library.

[Engelbert Tijskens]

Hi joel,

i did as you told and included 

nt2/include/functions/log.hpp 

nt2/include/functions/pow.hpp

compiling with gcc 4.8.1 didn't succeed, but icpc 14 did, so apparently it is a compiler issue. Are there any recommendations as to which gcc can be used?

kindest regards,

bert

[Mathias Gaunard]

All GCC versions from 4.1 onwards are supported.
What is your error message?

[Joel Falcou]

On 28/03/2014 11:50, Engelbert Tijskens wrote:
>

> Hi joel,
> i did as you told and included
> nt2/include/functions/log.hpp
> nt2/include/functions/pow.hpp
> compiling with gcc 4.8.1 didn't succeed, but icpc 14 did, so
> apparently it is a compiler issue. Are there any recommendations as to
> which gcc can be used?
> kindest regards,
> bert

Strange, care to give us the actual compilation error ?

[Engelbert Tijskens]

Hi Joel, Mathias,
i attached a stripped down version of the source file main.hpp resulting in the error below 

many thanks for your consideration

kindest regards, bert

12:22:21 **** Incremental Build of configuration Debug for project boost-simd-log ****

make all 

Building file: ../main.cpp

Invoking: GCC C++ Compiler

g++ -std=c++0x -I/opt/intel/composer_xe_2013_sp1.2.144/ipp/include -I/opt/intel/composer_xe_2013_sp1.2.144/mkl/include -I/opt/intel/composer_xe_2013_sp1.2.144/tbb/include -I/home/etijskens/software/boost/1_55_0/include -I/home/etijskens/software/nt2/Release/include -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"main.d" -MT"main.d" -o "main.o" "../main.cpp"

../main.cpp: In function ‘int main()’:

../main.cpp:36:47: error: cannot convert ‘svfloat_t {aka boost::simd::pack<float>}’ to ‘double’ for argument ‘1’ to ‘double log(double)’

         boost::simd::aligned_store( log( sv_x ), &z_[i] );

                                               ^

../main.cpp:41:52: error: cannot convert ‘svfloat_t {aka boost::simd::pack<float>}’ to ‘double’ for argument ‘1’ to ‘double pow(double, double)’

         boost::simd::aligned_store( pow( sv_x, sv_y), &z_[i] );

                                                    ^

../main.cpp:14:18: warning: unused variable ‘nreps’ [-Wunused-variable]

     size_t const nreps=10000;

                  ^

make: *** [main.o] Error 1

12:22:33 Build Finished (took 11s.741ms)

[Mathias Gaunard]

Simply qualify log and pow.
nt2::log(sv_x) etc.

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[Engelbert Tijskens]

unfortunately that does not help. 

(which i expected because icpc does not need the qualification.)

the error then is 

14:22:23 **** Incremental Build of configuration Debug for project boost-simd-log ****

make all 

Building file: ../main.cpp

Invoking: GCC C++ Compiler

g++ -std=c++0x -I/opt/intel/composer_xe_2013_sp1.2.144/ipp/include -I/opt/intel/composer_xe_2013_sp1.2.144/mkl/include -I/opt/intel/composer_xe_2013_sp1.2.144/tbb/include -I/home/etijskens/software/boost/1_55_0/include -I/home/etijskens/software/nt2/Release/include -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"main.d" -MT"main.d" -o "main.o" "../main.cpp"

../main.cpp: In function ‘int main()’:

../main.cpp:14:18: warning: unused variable ‘nreps’ [-Wunused-variable]

     size_t const nreps=10000;

                  ^

In file included from /home/etijskens/software/boost/1_55_0/include/boost/type_traits/is_volatile.hpp:28:0,

                 from /home/etijskens/software/boost/1_55_0/include/boost/type_traits/intrinsics.hpp:207,

                 from /home/etijskens/software/boost/1_55_0/include/boost/type_traits/is_class.hpp:14,

                 from /home/etijskens/software/nt2/Release/include/boost/simd/sdk/details/aliasing.hpp:14,

                 from /home/etijskens/software/nt2/Release/include/boost/simd/sdk/simd/native_fwd.hpp:12,

                 from /home/etijskens/software/nt2/Release/include/boost/simd/sdk/simd/meta/extension_of.hpp:15,

                 from /home/etijskens/software/nt2/Release/include/boost/simd/sdk/simd/extensions/meta/sse.hpp:16,

                 from /home/etijskens/software/nt2/Release/include/boost/simd/sdk/simd/extensions/x86/sse2.hpp:48,

                 from /home/etijskens/software/nt2/Release/include/boost/simd/sdk/simd/extensions/x86.hpp:29,

                 from /home/etijskens/software/nt2/Release/include/boost/simd/sdk/simd/extensions/extensions.hpp:5,

                 from /home/etijskens/software/nt2/Release/include/boost/simd/sdk/simd/extensions.hpp:16,

                 from /home/etijskens/software/nt2/Release/include/boost/simd/sdk/simd/pack.hpp:12,

                 from ../main.cpp:4:

/home/etijskens/software/boost/1_55_0/include/boost/type_traits/detail/cv_traits_impl.hpp: In instantiation of ‘struct boost::detail::cv_traits_imp<boost::simd::logical<float>*>’:

/home/etijskens/software/boost/1_55_0/include/boost/type_traits/is_const.hpp:64:4:   required from ‘const bool boost::detail::is_const_rvalue_filter<boost::simd::logical<float> >::value’

/home/etijskens/software/boost/1_55_0/include/boost/type_traits/is_const.hpp:77:1:   required from ‘struct boost::is_const<boost::simd::logical<float> >’

/home/etijskens/software/nt2/Release/include/boost/simd/sdk/simd/native.hpp:66:5:   required from ‘struct boost::simd::native<boost::simd::logical<float>, boost::simd::tag::sse_, void>’

/home/etijskens/software/nt2/Release/include/nt2/exponential/functions/simd/common/pow.hpp:60:11:   required from ‘nt2::ext::implement<nt2::tag::pow_(boost::dispatch::meta::simd_<boost::dispatch::meta::floating_<T>, X>, boost::dispatch::meta::simd_<boost::dispatch::meta::floating_<T>, X>), boost::dispatch::tag::cpu_>::result_type nt2::ext::implement<nt2::tag::pow_(boost::dispatch::meta::simd_<boost::dispatch::meta::floating_<T>, X>, boost::dispatch::meta::simd_<boost::dispatch::meta::floating_<T>, X>), boost::dispatch::tag::cpu_>::operator()(const A0&, const A0&) const [with A0 = boost::simd::native<float, boost::simd::tag::sse_, void>; X = boost::simd::tag::sse_; nt2::ext::implement<nt2::tag::pow_(boost::dispatch::meta::simd_<boost::dispatch::meta::floating_<T>, X>, boost::dispatch::meta::simd_<boost::dispatch::meta::floating_<T>, X>), boost::dispatch::tag::cpu_>::result_type = boost::simd::native<float, boost::simd::tag::sse_, void>]’

/home/etijskens/software/nt2/Release/include/boost/simd/dsl/functions/generic/run.hpp:210:33:   required from ‘boost::simd::ext::implement<boost::simd::tag::run_(boost::dispatch::meta::node_<Expr, boost::dispatch::meta::unspecified_<Tag>, mpl_::long_<2l>, D>), boost::dispatch::tag::formal_>::result_type boost::simd::ext::implement<boost::simd::tag::run_(boost::dispatch::meta::node_<Expr, boost::dispatch::meta::unspecified_<Tag>, mpl_::long_<2l>, D>), boost::dispatch::tag::formal_>::operator()(Expr&) const [with Expr = const boost::simd::expression<boost::proto::exprns_::expr<nt2::tag::pow_, boost::proto::argsns_::list2<boost::simd::expression<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<const boost::simd::native<float, boost::simd::tag::sse_, void>&>, 0l>, const boost::simd::native<float, boost::simd::tag::sse_, void>&>, boost::simd::expression<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<const boost::simd::native<float, boost::simd::tag::sse_, void>&>, 0l>, const boost::simd::native<float, boost::simd::tag::sse_, void>&> >, 2l>, boost::simd::native<float, boost::simd::tag::sse_, void> >; T = nt2::tag::pow_; D = boost::simd::domain; boost::simd::ext::implement<boost::simd::tag::run_(boost::dispatch::meta::node_<Expr, boost::dispatch::meta::unspecified_<Tag>, mpl_::long_<2l>, D>), boost::dispatch::tag::formal_>::result_type = boost::simd::native<float, boost::simd::tag::sse_, void>]’

/home/etijskens/software/nt2/Release/include/boost/simd/dsl/functions/run.hpp:23:3:   required from ‘typename boost::dispatch::meta::result_of<typename boost::dispatch::meta::dispatch_call<boost::simd::tag::run_(const A0&)>::type(const A0&)>::type boost::simd::run(const A0&) [with A0 = boost::simd::expression<boost::proto::exprns_::expr<nt2::tag::pow_, boost::proto::argsns_::list2<boost::simd::expression<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<const boost::simd::native<float, boost::simd::tag::sse_, void>&>, 0l>, const boost::simd::native<float, boost::simd::tag::sse_, void>&>, boost::simd::expression<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<const boost::simd::native<float, boost::simd::tag::sse_, void>&>, 0l>, const boost::simd::native<float, boost::simd::tag::sse_, void>&> >, 2l>, boost::simd::native<float, boost::simd::tag::sse_, void> >; typename boost::dispatch::meta::result_of<typename boost::dispatch::meta::dispatch_call<boost::simd::tag::run_(const A0&)>::type(const A0&)>::type = boost::simd::native<float, boost::simd::tag::sse_, void>]’

/home/etijskens/software/nt2/Release/include/boost/simd/dsl/functions/generic/evaluate.hpp:42:20:   required from ‘boost::simd::ext::implement<boost::simd::tag::evaluate_(boost::dispatch::meta::ast_<A0, D>), boost::dispatch::tag::formal_>::result_type boost::simd::ext::implement<boost::simd::tag::evaluate_(boost::dispatch::meta::ast_<A0, D>), boost::dispatch::tag::formal_>::operator()(A0&) const [with A0 = const boost::simd::expression<boost::proto::exprns_::expr<nt2::tag::pow_, boost::proto::argsns_::list2<boost::simd::expression<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<const boost::simd::native<float, boost::simd::tag::sse_, void>&>, 0l>, const boost::simd::native<float, boost::simd::tag::sse_, void>&>, boost::simd::expression<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<const boost::simd::native<float, boost::simd::tag::sse_, void>&>, 0l>, const boost::simd::native<float, boost::simd::tag::sse_, void>&> >, 2l>, boost::simd::native<float, boost::simd::tag::sse_, void> >; D = boost::simd::domain; boost::simd::ext::implement<boost::simd::tag::evaluate_(boost::dispatch::meta::ast_<A0, D>), boost::dispatch::tag::formal_>::result_type = boost::simd::native<float, boost::simd::tag::sse_, void>]’

/home/etijskens/software/nt2/Release/include/boost/simd/dsl/functions/evaluate.hpp:19:3:   required from ‘typename boost::dispatch::meta::result_of<typename boost::dispatch::meta::dispatch_call<boost::simd::tag::evaluate_(const A0&)>::type(const A0&)>::type boost::simd::evaluate(const A0&) [with A0 = boost::simd::expression<boost::proto::exprns_::expr<nt2::tag::pow_, boost::proto::argsns_::list2<boost::simd::expression<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<const boost::simd::native<float, boost::simd::tag::sse_, void>&>, 0l>, const boost::simd::native<float, boost::simd::tag::sse_, void>&>, boost::simd::expression<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<const boost::simd::native<float, boost::simd::tag::sse_, void>&>, 0l>, const boost::simd::native<float, boost::simd::tag::sse_, void>&> >, 2l>, boost::simd::native<float, boost::simd::tag::sse_, void> >; typename boost::dispatch::meta::result_of<typename boost::dispatch::meta::dispatch_call<boost::simd::tag::evaluate_(const A0&)>::type(const A0&)>::type = boost::simd::native<float, boost::simd::tag::sse_, void>]’

/home/etijskens/software/nt2/Release/include/boost/simd/memory/functions/simd/pack/aligned_store.hpp:68:45:   required from ‘boost::simd::ext::implement<boost::simd::tag::aligned_store_(boost::dispatch::meta::ast_<A0, boost::simd::domain>, boost::dispatch::meta::iterator_<boost::dispatch::meta::unspecified_<Tag> >), boost::dispatch::tag::cpu_>::result_type boost::simd::ext::implement<boost::simd::tag::aligned_store_(boost::dispatch::meta::ast_<A0, boost::simd::domain>, boost::dispatch::meta::iterator_<boost::dispatch::meta::unspecified_<Tag> >), boost::dispatch::tag::cpu_>::operator()(const A0&, A1) const [with A0 = const boost::simd::expression<boost::proto::exprns_::expr<nt2::tag::pow_, boost::proto::argsns_::list2<boost::simd::expression<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<const boost::simd::native<float, boost::simd::tag::sse_, void>&>, 0l>, const boost::simd::native<float, boost::simd::tag::sse_, void>&>, boost::simd::expression<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<const boost::simd::native<float, boost::simd::tag::sse_, void>&>, 0l>, const boost::simd::native<float, boost::simd::tag::sse_, void>&> >, 2l>, boost::simd::native<float, boost::simd::tag::sse_, void> >; A1 = float*; boost::simd::ext::implement<boost::simd::tag::aligned_store_(boost::dispatch::meta::ast_<A0, boost::simd::domain>, boost::dispatch::meta::iterator_<boost::dispatch::meta::unspecified_<Tag> >), boost::dispatch::tag::cpu_>::result_type = void]’

/home/etijskens/software/nt2/Release/include/boost/simd/memory/functions/aligned_store.hpp:123:20:   required from ‘void boost::simd::aligned_store(const Value&, const Pointer&) [with Value = boost::simd::expression<boost::proto::exprns_::expr<nt2::tag::pow_, boost::proto::argsns_::list2<boost::simd::expression<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<const boost::simd::native<float, boost::simd::tag::sse_, void>&>, 0l>, const boost::simd::native<float, boost::simd::tag::sse_, void>&>, boost::simd::expression<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<const boost::simd::native<float, boost::simd::tag::sse_, void>&>, 0l>, const boost::simd::native<float, boost::simd::tag::sse_, void>&> >, 2l>, boost::simd::native<float, boost::simd::tag::sse_, void> >; Pointer = float*]’

../main.cpp:41:67:   required from here

/home/etijskens/software/boost/1_55_0/include/boost/type_traits/detail/cv_traits_impl.hpp:36:1: internal compiler error: in finish_member_declaration, at cp/semantics.c:2686

 {

 ^

Please submit a full bug report,

with preprocessed source if appropriate.

See <file:///usr/share/doc/gcc-4.8/README.Bugs> for instructions.

Preprocessed source stored into /tmp/ccoKDSI4.out file, please attach this to your bugreport.

make: *** [main.o] Error 1

14:23:09 Build Finished (took 46s.205ms)

[Joel Falcou]

On 28/03/2014 14:27, Engelbert Tijskens wrote:

unfortunately that does not help. 

(which i expected because icpc does not need the qualification.)

Add

-fno-strict-aliasing -DBOOST_SIMD_NO_STRICT_ALIASING

to the command line.

[Mathias Gaunard]

On 28/03/2014 14:27, Engelbert Tijskens wrote:

> unfortunately that does not help.
> (which i expected because icpc does not need the qualification.)

icpc might be wrong here, I don't think it should get selected
automatically.

> /home/etijskens/software/boost/1_55_0/include/boost/type_traits/detail/cv_traits_impl.hpp:36:1:
> internal compiler error: in finish_member_declaration, at
> cp/semantics.c:2686
> {
> ^
> Please submit a full bug report,
> with preprocessed source if appropriate.
>
> See <file:///usr/share/doc/gcc-4.8/README.Bugs> for instructions.
> Preprocessed source stored into /tmp/ccoKDSI4.out file, please attach
> this to your bugreport.

As the error message says, you ran into a compiler bug.
It is tied to the GCC-specific may_alias attribute, you can work around
it with the option Joel gave in his message.