[llvm-branch-commits] [flang] [flang] Skip processing reductions for unstructured `do concurrent` loops (PR #150188)

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llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-flang-fir-hlfir

Author: Kareem Ergawy (ergawy)

<details>
<summary>Changes</summary>

Fixes #<!-- -->149563

When emitting unstructured `do concurrent` loops, reduction processing should be skipped since we are not emitting `fir.do_concurrent` loop in the first place.

---
Full diff: https://github.com/llvm/llvm-project/pull/150188.diff


2 Files Affected:

- (modified) flang/lib/Lower/Bridge.cpp (+3) 
- (modified) flang/test/Lower/do_loop_unstructured.f90 (+19) 


``````````diff
diff --git a/flang/lib/Lower/Bridge.cpp b/flang/lib/Lower/Bridge.cpp
index 13420f365919d..a6362b1e2f5ca 100644
--- a/flang/lib/Lower/Bridge.cpp
+++ b/flang/lib/Lower/Bridge.cpp
@@ -2115,6 +2115,9 @@ class FirConverter : public Fortran::lower::AbstractConverter {
       }
     }
 
+    if (!doConcurrentLoopOp)
+      return;
+
     llvm::SmallVector<bool> reduceVarByRef;
     llvm::SmallVector<mlir::Attribute> reductionDeclSymbols;
     llvm::SmallVector<mlir::Attribute> nestReduceAttrs;
diff --git a/flang/test/Lower/do_loop_unstructured.f90 b/flang/test/Lower/do_loop_unstructured.f90
index d8890b2d0926e..176ea5ccee129 100644
--- a/flang/test/Lower/do_loop_unstructured.f90
+++ b/flang/test/Lower/do_loop_unstructured.f90
@@ -232,3 +232,22 @@ subroutine nested_structured_in_unstructured()
 ! CHECK:   cf.br ^[[HEADER]]
 ! CHECK: ^[[EXIT]]:
 ! CHECK:   return
+
+subroutine unstructured_do_concurrent
+  logical :: success
+  do concurrent (i=1:10) local(success)
+    error stop "fail"
+  enddo
+end
+! CHECK-LABEL: func.func @_QPunstructured_do_concurrent
+! CHECK:         %[[ITER_VAR:.*]] = fir.alloca i32
+
+! CHECK:       ^[[HEADER]]:
+! CHECK:         %{{.*}} = fir.load %[[ITER_VAR]] : !fir.ref<i32>
+! CHECK:         cf.cond_br %{{.*}}, ^[[BODY:.*]], ^[[EXIT:.*]]
+
+! CHECK:       ^[[BODY]]:
+! CHECK-NEXT:    %{{.*}} = fir.alloca !fir.logical<4> {bindc_name = "success", {{.*}}}
+
+! CHECK:       ^[[EXIT]]:
+! CHECK-NEXT:    return

``````````

</details>


https://github.com/llvm/llvm-project/pull/150188