[PATCH] Enable use of #pragma omp simd reduction(inscan,...) even for GCC10+ in PSTL

[Jonathan Wakely]

On 24/06/19 15:18 -0700, Thomas Rodgers wrote:
>
>Ok for trunk.

Yup, this is OK then, thanks for checking it, Thomas.


>> Can you push it into upstream PSTL?
>
>Yes.
>
>Thanks,
>Tom.
>
>Jakub Jelinek writes:
>
>> Hi!
>>
>> Now that GCC supports inclusive/exclusive scans (like ICC 19.0 so far in
>> simd constructs only), we can enable it in PSTL as well.
>>
>> Bootstrapped/regtested on x86_64-linux and i686-linux, additionally tested
>> with
>> #include <execution>
>> #include <numeric>
>>
>> auto
>> foo (std::vector<int> &ca, std::vector<int> &co)
>> {
>>   return std::inclusive_scan(std::execution::unseq, ca.begin(), ca.end(), co.begin());
>> }
>>
>> auto
>> bar (std::vector<int> &ca, std::vector<int> &co)
>> {
>>   return std::exclusive_scan(std::execution::unseq, ca.begin(), ca.end(), co.begin(), 0);
>> }
>> and verifying with -O2 -fopenmp-simd it is vectorized.  Ok for trunk?
>> Can you push it into upstream PSTL?
>>
>> 2019-06-21  Jakub Jelinek  <jakub@redhat.com>
>>
>> 	* include/pstl/pstl_config.h (_PSTL_PRAGMA_SIMD_SCAN,
>> 	_PSTL_PRAGMA_SIMD_INCLUSIVE_SCAN, _PSTL_PRAGMA_SIMD_EXCLUSIVE_SCAN):
>> 	Define to OpenMP 5.0 pragmas even for GCC 10.0+.
>> 	(_PSTL_UDS_PRESENT): Define to 1 for GCC 10.0+.
>>
>> --- libstdc++-v3/include/pstl/pstl_config.h.jj	2019-06-10 18:18:01.551191212 +0200
>> +++ libstdc++-v3/include/pstl/pstl_config.h	2019-06-20 17:03:31.466367344 +0200
>> @@ -70,7 +70,7 @@
>>  #    define _PSTL_PRAGMA_FORCEINLINE
>>  #endif
>>
>> -#if (__INTEL_COMPILER >= 1900)
>> +#if (__INTEL_COMPILER >= 1900) || (_PSTL_GCC_VERSION >= 100000)
>>  #    define _PSTL_PRAGMA_SIMD_SCAN(PRM) _PSTL_PRAGMA(omp simd reduction(inscan, PRM))
>>  #    define _PSTL_PRAGMA_SIMD_INCLUSIVE_SCAN(PRM) _PSTL_PRAGMA(omp scan inclusive(PRM))
>>  #    define _PSTL_PRAGMA_SIMD_EXCLUSIVE_SCAN(PRM) _PSTL_PRAGMA(omp scan exclusive(PRM))
>> @@ -100,7 +100,11 @@
>>  #    define _PSTL_UDR_PRESENT 0
>>  #endif
>>
>> -#define _PSTL_UDS_PRESENT (__INTEL_COMPILER >= 1900 && __INTEL_COMPILER_BUILD_DATE >= 20180626)
>> +#if ((__INTEL_COMPILER >= 1900 && __INTEL_COMPILER_BUILD_DATE >= 20180626) || _PSTL_GCC_VERSION >= 100000)
>> +#    define _PSTL_UDS_PRESENT 1
>> +#else
>> +#    define _PSTL_UDS_PRESENT 0
>> +#endif
>>
>>  #if _PSTL_EARLYEXIT_PRESENT
>>  #    define _PSTL_PRAGMA_SIMD_EARLYEXIT _PSTL_PRAGMA(omp simd early_exit)
>>
>> 	Jakub
>