[llvm-commits] [cfe-commits] [PATCH] First OpenMP patch

[Mahesha HS]

That is fine. I will experiment with GCC for different flags like -W,
-Wall etc. And make sure that the implementation is in compatible with
GCC (when it is not really a bug-to-bug compatible). I think, this
additional implementation will be on top of what the current patch
contains. This, I will send as an another patch.

Do you guys agree to the internal requirement for two lang options -
OpenMP and NoOpenMP - to keep track of the options -fopenmp and
-fno-openmp? If so, I will change the "comment and test case" as
mentioned by Joey and re-submit the patch.

--
mahesha





On Thu, Nov 22, 2012 at 2:09 AM, Hal Finkel <hfinkel at anl.gov> wrote:
> ----- Original Message -----
>> From: "Dmitri Gribenko" <gribozavr at gmail.com>
>> To: "Mahesha HS" <mahesha.llvm at gmail.com>
>> Cc: "Benjamin Kramer" <benny.kra at gmail.com>, "llvm cfe" <cfe-commits at cs.uiuc.edu>
>> Sent: Wednesday, November 21, 2012 11:06:50 AM
>> Subject: Re: [cfe-commits] [PATCH] First OpenMP patch
>>
>> On Wed, Nov 21, 2012 at 6:02 PM, Mahesha HS <mahesha.llvm at gmail.com>
>> wrote:
>> > Though -fopenmp and -fno-openmp are mutually exclusive options,
>> > underlying functionality, that we intended to implement differ a
>> > little. In a nutshell, we, sometime back discussed in CFE DEV list
>> > to
>> > implement OpenMP as follows. We thought that passing neither
>> > -fopenmp
>> > nor -fno-openmp  is not same as passing only -fno-openmp.
>> >  Following
>> > is the intended implementation. This forced me to add two lang
>> > options
>> > as I could not handle it using only one lang option. If this was
>> > not
>> > there, I guess, all your comments would not have araised.
>> >
>> > if (source contains OpenMP statements) {
>> >      if (neither -fopenmp nor -fno-openmp present) {
>> >          Throw warning.
>> >      }
>> >      else if (only -fopenmp present) {
>> >          Process OpenMP
>> >      }
>> >      else if (only -fno-openmp) {
>> >         Silently ignore OpenMP. Do not throw warning.
>> >      }
>> >     else if (both -fopenmp and -fno-openmp are present) {
>> >         Decide based on which one appears later in the command
>> >         line.
>> >     }
>> > }
>>
>> I think the implementation should use the general diagnostics
>> infrastructure.  For example, by default add something like
>> -Wsource-uses-openmp and disable it in case of -fno-openmp.
>>
>> $ g++ -W -Wall /tmp/zzz.cc
>> /tmp/zzz.cc:3:0: warning: ignoring #pragma omp barrier
>> [-Wunknown-pragmas]
>>
>> By the way, the algorithm above is not consistent with gcc, which
>> ignores the pragma when no -f flag is passed.
>
> I think that we'd like to act the way that gcc does, except that we don't want to warn about unused OpenMP pragmas when -fno-openmp is given even if -Wall is also specified.
>
>  -Hal
>
>>
>> Dmitri
>>
>> --
>> main(i,j){for(i=2;;i++){for(j=2;j<i;j++){if(!(i%j)){j=0;break;}}if
>> (j){printf("%d\n",i);}}} /*Dmitri Gribenko <gribozavr at gmail.com>*/
>> _______________________________________________
>> cfe-commits mailing list
>> cfe-commits at cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
>>
>
> --
> Hal Finkel
> Postdoctoral Appointee
> Leadership Computing Facility
> Argonne National Laboratory



-- 
mahesha