[ros-users] Question about cmake and SSE optimizations
Jose Gonzalez
de0a100 at gmail.com
Tue Mar 23 18:47:02 UTC 2010
Here is the version I got with SSE3 (I'm not familiar with MSVC so I
didn't include it)
# check for SSE extensions
include(CheckCXXSourceRuns)
if( CMAKE_COMPILER_IS_GNUCC OR CMAKE_COMPILER_IS_GNUCXX )
set(SSE_FLAGS)
set(CMAKE_REQUIRED_FLAGS "-msse3")
check_cxx_source_runs("
#include <pmmintrin.h>
int main()
{
__m128d a, b;
double vals[2] = {0};
a = _mm_loadu_pd(vals);
b = _mm_hadd_pd(a,a);
_mm_storeu_pd(vals, b);
return 0;
}"
HAS_SSE3_EXTENSIONS)
set(CMAKE_REQUIRED_FLAGS "-msse2")
check_cxx_source_runs("
#include <emmintrin.h>
int main()
{
__m128d a, b;
double vals[2] = {0};
a = _mm_loadu_pd(vals);
b = _mm_add_pd(a,a);
_mm_storeu_pd(vals,b);
return 0;
}"
HAS_SSE2_EXTENSIONS)
set(CMAKE_REQUIRED_FLAGS "-msse")
check_cxx_source_runs("
#include <xmmintrin.h>
int main()
{
__m128 a, b;
float vals[4] = {0};
a = _mm_loadu_ps(vals);
b = a;
b = _mm_add_ps(a,b);
_mm_storeu_ps(vals,b);
return 0;
}"
HAS_SSE_EXTENSIONS)
set(CMAKE_REQUIRED_FLAGS)
if(HAS_SSE3_EXTENSIONS)
message(STATUS "Using SSE3 extensions")
set(SSE_FLAGS "-msse3 -mfpmath=sse")
elseif(HAS_SSE2_EXTENSIONS)
message(STATUS "Using SSE2 extensions")
set(SSE_FLAGS "-msse2 -mfpmath=sse")
elseif(HAS_SSE_EXTENSIONS)
message(STATUS "Using SSE extensions")
set(SSE_FLAGS "-msse -mfpmath=sse")
endif()
add_definitions(${SSE_FLAGS})
elseif(MSVC)
check_cxx_source_runs("
#include <emmintrin.h>
int main()
{
__m128d a, b;
double vals[2] = {0};
a = _mm_loadu_pd(vals);
b = _mm_add_pd(a,a);
_mm_storeu_pd(vals,b);
return 0;
}"
HAS_SSE2_EXTENSIONS)
if( HAS_SSE2_EXTENSIONS )
message(STATUS "Using SSE2 extensions")
add_definitions( "/arch:SSE2 /fp:fast -D__SSE__ -D__SSE2__" )
endif()
endif()
On Tue, Mar 23, 2010 at 2:24 PM, Radu Bogdan Rusu <rusu at willowgarage.com> wrote:
> In terms of SSE only, we can safely go to the highest SSE version available.
>
> Brian Gerkey wrote:
>> It would be great to see this functionality wrapped up in a single
>> CMake macro, something like:
>> rosbuild_add_sse_flags(target)
>> It would do checks, compute flags, then call
>> rosbuild_add_compile_flags(target ...). Of course, this assumes that
>> you want the highest / best level of SSE available; I'm not familiar
>> enough with these optimizations to know if that's appropriate, or if
>> you'd rather have finer-grained control.
>>
>> I'd happily add such a macro to rosbuild, for general reuse. Come to
>> think of it, this would be a nice module to contribute to CMake
>> itself.
>>
>> brian.
>>
>> On Tue, Mar 23, 2010 at 11:14 AM, Radu Bogdan Rusu
>> <rusu at willowgarage.com> wrote:
>>> Great job Rosen! That's exactly what I had in mind.
>>>
>>> We should add SSE3 and SSE4. Gotta love that dot product :)
>>>
>>> Cheers,
>>> Radu.
>>>
>>> Rosen Diankov wrote:
>>>> i'm pasting cmake code i use for sse checks. it checks for both sse1
>>>> and sse2, although similar checks can be used for sse3-5, there's also
>>>> a check for msvc
>>>>
>>>> # check for SSE extensions
>>>> include(CheckCXXSourceRuns)
>>>> if( CMAKE_COMPILER_IS_GNUCC OR CMAKE_COMPILER_IS_GNUCXX )
>>>> set(SSE_FLAGS)
>>>>
>>>> set(CMAKE_REQUIRED_FLAGS "-msse2")
>>>> check_cxx_source_runs("
>>>> #include <emmintrin.h>
>>>>
>>>> int main()
>>>> {
>>>> __m128d a, b;
>>>> double vals[2] = {0};
>>>> a = _mm_loadu_pd(vals);
>>>> b = _mm_add_pd(a,a);
>>>> _mm_storeu_pd(vals,b);
>>>> return 0;
>>>> }"
>>>> HAS_SSE2_EXTENSIONS)
>>>>
>>>> set(CMAKE_REQUIRED_FLAGS "-msse")
>>>> check_cxx_source_runs("
>>>> #include <xmmintrin.h>
>>>> int main()
>>>> {
>>>> __m128 a, b;
>>>> float vals[4] = {0};
>>>> a = _mm_loadu_ps(vals);
>>>> b = a;
>>>> b = _mm_add_ps(a,b);
>>>> _mm_storeu_ps(vals,b);
>>>> return 0;
>>>> }"
>>>> HAS_SSE_EXTENSIONS)
>>>>
>>>> set(CMAKE_REQUIRED_FLAGS)
>>>>
>>>> if(HAS_SSE2_EXTENSIONS)
>>>> message(STATUS "Using SSE2 extensions")
>>>> set(SSE_FLAGS "-msse2 -mfpmath=sse")
>>>> elseif(HAS_SSE_EXTENSIONS)
>>>> message(STATUS "Using SSE extensions")
>>>> set(SSE_FLAGS "-msse -mfpmath=sse")
>>>> endif()
>>>>
>>>> add_definitions(${SSE_FLAGS})
>>>> elseif(MSVC)
>>>> check_cxx_source_runs("
>>>> #include <emmintrin.h>
>>>>
>>>> int main()
>>>> {
>>>> __m128d a, b;
>>>> double vals[2] = {0};
>>>> a = _mm_loadu_pd(vals);
>>>> b = _mm_add_pd(a,a);
>>>> _mm_storeu_pd(vals,b);
>>>> return 0;
>>>> }"
>>>> HAS_SSE2_EXTENSIONS)
>>>> if( HAS_SSE2_EXTENSIONS )
>>>> message(STATUS "Using SSE2 extensions")
>>>> add_definitions( "/arch:SSE2 /fp:fast -D__SSE__ -D__SSE2__" )
>>>> endif()
>>>> endif()
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> 2010/3/24 Jose Gonzalez <de0a100 at gmail.com>:
>>>>> Thanks for the comments?
>>>>>
>>>>> What about check_cxx_compiler_flag("-msse2" COMPILER_SUPPORT_SSE2)?
>>>>> Have you ever tried it?
>>>>>
>>>>> On Tue, Mar 23, 2010 at 12:16 PM, Radu Bogdan Rusu
>>>>> <rusu at willowgarage.com> wrote:
>>>>>> Depending on what compiler and cpu you use, some of these flags might be already turned on by default. You can check
>>>>>> that using:
>>>>>>
>>>>>> $ gcc -Q -O3 --help=target
>>>>>>
>>>>>> for example.
>>>>>>
>>>>>> Other than that, we don't have a proper way to enable/disable different SSE optimizations for now. Most ROS packages
>>>>>> cram a add_definitions ("-msse... etc") in their CMakeLists.txt.
>>>>>>
>>>>>> Patches to make this more standard across multiple platforms and enable/disable SSE1-5 automatically would be great!
>>>>>>
>>>>>> Cheers,
>>>>>> Radu.
>>>>>>
>>>>>> Jose Gonzalez wrote:
>>>>>>> Hi,
>>>>>>>
>>>>>>> Doing some experiments in the past with OpenCV (linux/g++) I realized
>>>>>>> that there is a significant performance difference between the
>>>>>>> versions compiled with autoconf and cmake. Digging in the compilation
>>>>>>> scripts I came to the conclusion that the only extra flags that were
>>>>>>> added by the autoconf scripts were the SSE optimizations (and openMP).
>>>>>>>
>>>>>>> Talking about the SSE optimizations, I can see how ROS sets the flags
>>>>>>> in a similar way. When the detected platform is i686, all the SSE
>>>>>>> optimizations are disabled by default (there is a comment "SSE/SSE2
>>>>>>> might probably be not available for some old AMD or VIA processors").
>>>>>>> Before finding out a solution by myself I'd like to ask the list if
>>>>>>> somebody knows a standard way of testing for SSE optimizations in
>>>>>>> cmake.
>>>>>>>
>>>>>>> Thanks,
>>>>>>> Jose
>>>>>>>
>>>>>>> ------------------------------------------------------------------------------
>>>>>>> Download Intel® Parallel Studio Eval
>>>>>>> Try the new software tools for yourself. Speed compiling, find bugs
>>>>>>> proactively, and fine-tune applications for parallel performance.
>>>>>>> See why Intel Parallel Studio got high marks during beta.
>>>>>>> http://p.sf.net/sfu/intel-sw-dev
>>>>>>> _______________________________________________
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>>>>>> --
>>>>>> | Radu Bogdan Rusu | http://rbrusu.com/
>>>>>> _______________________________________________
>>>>>> ros-users mailing list
>>>>>> ros-users at code.ros.org
>>>>>> https://code.ros.org/mailman/listinfo/ros-users
>>>>>>
>>>>> _______________________________________________
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>>>>>
>>> --
>>> | Radu Bogdan Rusu | http://rbrusu.com/
>>> _______________________________________________
>>> ros-users mailing list
>>> ros-users at code.ros.org
>>> https://code.ros.org/mailman/listinfo/ros-users
>>>
>
> --
> | Radu Bogdan Rusu | http://rbrusu.com/
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