[PATCH] D84182: [OPENMP]Fix PR46012: declare target pointer cannot be accessed in target region.

[Ye Luo via Phabricator via cfe-commits]

ye-luo added a comment.

In D84182#2173578 <https://reviews.llvm.org/D84182#2173578>, @grokos wrote:

> @ABataev:
>
> After this patch was committed, I tried to run the following example:
>
>   #include <stdio.h>
>   
>   int *yptr;
>   
>   int main() {
>     int y[10];
>     y[1] = 1;
>     yptr = &y[0];
>   
>     printf("&yptr = %p\n", &yptr);
>     printf("&y[0] = %p\n", &y[0]);
>   
>     #pragma omp target data map(to: yptr[0:5])
>     #pragma omp target
>     {
>       printf("y = %d\n", yptr[1]);
>       yptr[1] = 10;
>       printf("y = %d\n", yptr[1]);
>     }
>   
>     printf("y = %d\n", yptr[1]);
>     return 0;
>   }
>
> The arguments clang generates are:
>
>   1) base = &y[0], begin = &yptr, size = 8, type = TARGET_PARAM | TO
>   2) base = &yptr, begin = &y[0], size = 8, type = PTR_AND_OBJ | TO
>
> The second argument is correct, the first argument doesn't make much sense. I believe it should have its base set to &yptr, not &y[0].
> y[0] is not the base for anything, it's only the pointee object.

I hit the same issue and it results incorrect mapping.
https://bugs.llvm.org/show_bug.cgi?id=46868
In addition, only yptr is touched inside the target region. After this patch, two mappings instead of one occurs.


Repository:
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  https://reviews.llvm.org/D84182/new/

https://reviews.llvm.org/D84182