[PATCH] D105375: [OPENMP]Remove const firstprivate allocation as a variable in a constant space.

[Alexey Bataev via Phabricator via cfe-commits]

ABataev added a comment.

In D105375#2864733 <https://reviews.llvm.org/D105375#2864733>, @jhuber6 wrote:

> This revision causes a bug with generic regions. Firstprivate constants now aren't mapped properly into an internal parallel region and will just be zero. For example if I run this code I will see different values for the constants inside and outside the parallel region.
>
>   #include <complex>
>   #include <cstdio>
>   
>   void foo(const std::complex<double> X, std::complex<double> Y) {
>   #pragma omp target firstprivate(X) map(from:Y)
>     {
>       printf ("Outside parallel: %f + %fi\n", X.real(), X.imag());
>   #pragma omp parallel firstprivate(X)
>       {
>         printf ("Inside parallel: %f + %fi\n", X.real(), X.imag());
>         Y = X;
>       }
>     }
>   }
>   
>   int main() {
>     std::complex<double> X = {1.0, 1.0};
>     std::complex<double> Y;
>     foo(X, Y);
>   }
>
>   Outside parallel: 1.000000 + 1.000000i
>   Inside parallel: 0.000000 + 0.000000i
>
> I'm assuming they aren't being properly copied because they were originally global constants that had visibility everywhere.

Hi, thanks for the report. I think I know the reason, I prepared a patch D105647 <https://reviews.llvm.org/D105647>. Could you check if it fixes the issue?


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