[flang-commits] [flang] [flang][OpenMP] Lower cross-module operator declare reduction (PR #207493)

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MattPD wrote:

Fixed. The resolver now collects every distinct reduction the identifier reaches rather than stopping at the first. The clause is rejected when more than one distinct user-defined reduction supports the list item's type. The new logic covers the renamed-operator merge you described, the non-renamed same-name variant, and intrinsic-operator/special-function reduction-name collisions across modules. I added tests, including the USE-order-swap case.

One documented limitation remains, pinned by a test. In an inconsistent hermetic build, a same-named module is loaded at two versions. Flang does not distinguish them, because only the combiner body differs. The limitation matches Flang's existing tolerance of such builds.


https://github.com/llvm/llvm-project/pull/207493