A focused walkthrough of REX's `checkOmpAnalyzing` layer: `-rose:openmp:analyzing`, targeted AST assertions for schedule defaults and implicit target mapping, and why this semantic-analysis checkpoint sits between frontend AST coverage and lowering tests.

A focused walkthrough of the broad `OpenMP_tests` frontend corpus in REX: `parseOmp` in `ast_only` mode, `rose_*` output generation, OpenMP-line reference diffs, mixed OpenMP/OpenACC cases, multi-file and macro-preservation checks, and the separate Fortran AST-coverage slice.

A focused walkthrough of the standalone `ompparser` stage in REX: lexer and grammar, location-aware `OpenMPIR`, expression callbacks, clause normalization, round-trip unparsing, and the tests that validate the parser before AST construction begins.

A focused walkthrough of REX's `lowering_cpu` suite: why it compares original and lowered OpenMP programs on the same CPU runtime, how exact and sorted comparison modes work, and which semantic regressions this layer catches before GPU benchmarks.

A focused walkthrough of the `lowering_rodinia` suite in REX: reduced Rodinia-like inputs, invariant-based checks on generated host and device files, and the specific regression classes this layer catches.

A focused walkthrough of the generated artifact model for REX GPU offloading: the rewritten host file, the synthesized device file, and the shared helper/runtime files that make the build work.

A focused walkthrough of how REX lowers OpenMP `target data` regions, reuses the same mapping vocabulary as kernel launches, and preserves data lifetimes across multiple kernels and repeated calls.

A focused walkthrough of the ABI-critical runtime packet in REX GPU lowering: `__args*` arrays, static and dynamic map-entry handling, and the final `__tgt_kernel_arguments` structure.

Why Codex with GPT-5.2 felt like a step change in persistence, why older models and other tools often stopped early, and what Crush and Zeroclaw would need to do to close that gap.

A focused walkthrough of the host-side launch block in REX GPU lowering: kernel identity, launch geometry, replacement of the original target region, and the bridge to runtime argument packaging.