[flang] [llvm] [flang][llvm][OpenMP][OpenACC] Add implicit casts to omp.atomic and acc.atomic (PR #131603)

[Tom Eccles via llvm-commits]

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@@ -386,6 +442,7 @@ void genOmpAccAtomicRead(Fortran::lower::AbstractConverter &converter,
       fir::getBase(converter.genExprAddr(fromExpr, stmtCtx));
   mlir::Value toAddress = fir::getBase(converter.genExprAddr(
       *Fortran::semantics::GetExpr(assignmentStmtVariable), stmtCtx));
+  emitImplicitCast(converter, loc, fromAddress, toAddress, elementType);
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tblah wrote:

 I think progress with your patch could still be desirable in case there are subtle differences between casting in C and Fortran, however waiting 2 weeks is okay. If at all possible I would like this to be fixed for LLVM 21 though. I am happy to take over fixing the bugs myself if you won't have time.

If Michael's patch lands we could test the casting to see if it is doing the right thing without these changes.

https://github.com/llvm/llvm-project/pull/131603