[flang] Fix simplify intrinsic for count not checking for rank = 0 properly

[SBallantyne]

Summary

Simple fix to check for rank in the same way as other intrinsics to allow
runtime count to take over when dealing with unknown dimension arrays.

Fixes #60356

[kiranchandramohan]

flang/lib/Optimizer/Transforms/SimplifyIntrinsics.cpp

624

Could you add a comment, detailing what this check means? (possibly just copying the summary here),
Could you add a test to ensure that simplify logical reduction does not happen for this case?

[SBallantyne]

Add test and comment

[Leporacanthicus]

Looks OK except for the test checking for the wrong "Not".

flang/test/Transforms/simplifyintrinsics.fir

1239 ↗

(On Diff #493250)

Should be FortranACount without Dim, right? (And two lines down too)

[SBallantyne]

Fix minor issue with tests.

[Leporacanthicus]

LGTM, thanks for fixing!

[kiranchandramohan]

flang/lib/Optimizer/Transforms/SimplifyIntrinsics.cpp

624

Could you check why the rank is 0 for assumed shape arrays?

flang/lib/Optimizer/Transforms/SimplifyIntrinsics.cpp

 }
 
 void SimplifyIntrinsicsPass::simplifyLogicalReduction(
     fir::CallOp call, const fir::KindMapping &kindMap,
     GenReductionBodyTy genBodyFunc) {
 
   mlir::Operation::operand_range args = call.getArgs();
   const mlir::Value &dim = args[3];
+  unsigned rank = getDimCount(args[0]);
 
-  if (!isZero(dim))
+  if (!(isZero(dim) && rank > 0))
     return;
 
-  unsigned rank = getDimCount(args[0]);
   mlir::SymbolRefAttr callee = call.getCalleeAttr();
 
   fir::FirOpBuilder builder{getSimplificationBuilder(call, kindMap)};
   std::string funcName =
       (mlir::Twine{callee.getLeafReference().getValue(), "x"} +
        mlir::Twine{rank})
           .str();