{"id":"4142a665-1ade-456e-883d-4c101346adee","arxiv_id":"2605.16595","paper_version":1,"verdict":"UNVERDICTED","confidence":"LOW","novelty_score":6.0,"correctness_risk":"unknown","formal_verification":"none","parameter_count":0,"one_line_summary":"qstack introduces callback wrapping in a quantum IR to allow compositional end-to-end compilation of fault-tolerant quantum programs including concatenated error-correcting codes without manual classical logic adaptation.","lead":"qstack is a compiler framework using a purely quantum intermediate representation where classical logic is handled via opaque callbacks. This enables automatic adaptation of both quantum operations and classical feedback during compositional passes for error correction and hardware translation.","discovery_kind":"new_method","skeptic_critique":{"model":"grok-4.3","headline":"Opaque callback wrapping may fail to preserve hybrid semantics for dynamically generated kernels during code concatenation","rationale":"The reader's weakest assumption directly identifies the opacity requirement as load-bearing. The absence of formal verification or equivalence checking in the reported results makes this the single point where the compositional claim is least secure; confirming or refuting it via the concrete test would decide whether the central mechanism works as stated.","tokens_in":1697,"tokens_out":337,"duration_ms":52690,"concrete_test":"Extract the minimal single-qubit feedback loop used in the bit-flip repetition pass; manually apply the described callback wrapping for one repetition layer followed by a second layer, then compare the resulting classical control-flow graph and measurement-to-correction mapping against the original; if any branch or input value differs, the semantics-preservation assumption does not hold.","verdict_should_be":"CONDITIONAL","load_bearing_attack":"The central claim requires that callback wrapping adapts both quantum ops and classical callbacks while any dynamically generated kernel is fed through the full pipeline, all without inspecting callback internals. For this to hold across compositions (e.g., two repetition passes yielding Shor code), the wrapping must preserve the exact timing, inputs, and outputs of classical feedback logic relative to syndrome measurements. Because callbacks remain opaque and may be written in arbitrary classical languages, any implicit dependence on measurement representation, runtime context, or side effects could be broken by an earlier pass (ISA translation or prior code layer), altering the effective hybrid program. The demonstration of end-to-end compilation for repetition, Steane, and Shor codes does not address whether equivalence was checked for the classical control flow.","agreement_with_reader":"agree"},"referee_report":{"model":"grok-4.3","summary":"The manuscript introduces qstack, a compiler framework for end-to-end compilation of fault-tolerant quantum programs. It defines a purely quantum intermediate representation in which classical logic is accessed exclusively through opaque callbacks written in arbitrary classical languages. The central mechanism is callback wrapping, which automatically adapts both quantum operations and their associated classical callbacks during each compiler pass; any kernel dynamically generated by a callback is fed through the full pipeline. This design allows ISA translation and quantum error correction (including concatenation of codes) to be expressed as composable passes without manual adaptation of classical logic. The paper demonstrates the approach by compiling from a high-level gate set through Clifford gates to trapped-ion native operations, obtaining bit-flip and phase-flip repetition codes, the Steane code, and the Shor code via composition of two repetition passes.","tokens_in":1846,"tokens_out":588,"duration_ms":43996,"significance":"If the semantic-preservation properties hold, the framework would remove the need for manual rewriting of classical feedback logic at each abstraction layer, enabling more reliable compositional construction of fault-tolerant programs. The support for arbitrary classical languages inside opaque callbacks and the explicit handling of dynamically generated kernels are distinctive strengths. The demonstration on repetition, Steane, and Shor codes provides concrete evidence of the compositional workflow, though the absence of formal semantic arguments or equivalence checks limits the immediate impact on verified compilation pipelines.","major_comments":[{"comment":"Abstract and demonstration section: the central claim that callback wrapping preserves hybrid semantics for dynamically generated kernels (including exact timing, inputs, and outputs of classical feedback relative to syndrome measurements) is not supported by any semantic-preservation argument, error analysis, or equivalence verification. The Shor-code example obtained by composing two repetition passes therefore does not establish that classical control flow remains intact when callbacks remain opaque and may contain implicit dependencies on measurement representation or runtime context.","section":"Abstract / Demonstration"},{"comment":"Framework description (callback-wrapping mechanism): because callbacks are treated as black boxes written in arbitrary classical languages, the paper does not address how an earlier pass (e.g., ISA translation) could alter the effective hybrid program without inspecting or modifying callback internals. This assumption is load-bearing for the compositional claim yet receives no concrete test or counter-example analysis.","section":"Framework description"}],"minor_comments":[{"comment":"The abstract refers to a 'purely quantum intermediate representation' without a dedicated figure or early section that defines its syntax and the precise interface to opaque callbacks.","section":"Abstract"}],"recommendation":"major_revision","confidential_remarks":"The manuscript is primarily a framework description accompanied by a demonstration rather than a formal verification result. The journal's scope for systems or tools papers should be checked against the level of rigor expected for claims of semantic preservation in hybrid quantum-classical compilation."},"author_rebuttal":{"model":"grok-4.3","summary":"We thank the referee for the constructive comments on our manuscript. We address each major comment below with clarifications on the design and evidence provided. We plan revisions to strengthen the discussion of semantic properties and the opaque callback mechanism.","responses":[{"response":"We acknowledge that the manuscript provides no formal semantic-preservation argument, error analysis, or equivalence verification. The Shor-code demonstration via composition of two repetition passes shows that dynamically generated kernels are fed through the full pipeline and that the resulting program executes correctly for the chosen codes. This offers practical evidence that classical feedback logic is preserved in the examples. We agree this does not constitute a rigorous proof for arbitrary opaque callbacks with potential implicit dependencies. In revision we will expand the discussion section with an informal argument describing how wrapping maintains relative timing and input/output interfaces for feedback, and we will note formal verification as future work.","revision_made":"partial","referee_comment":"[Abstract / Demonstration] Abstract and demonstration section: the central claim that callback wrapping preserves hybrid semantics for dynamically generated kernels (including exact timing, inputs, and outputs of classical feedback relative to syndrome measurements) is not supported by any semantic-preservation argument, error analysis, or equivalence verification. The Shor-code example obtained by composing two repetition passes therefore does not establish that classical control flow remains intact when callbacks remain opaque and may contain implicit dependencies on measurement representation or runtime context."},{"response":"The framework deliberately keeps callbacks opaque to accommodate arbitrary classical languages. Callback wrapping transforms the quantum operations and the calling interface so that the classical code receives measurement outcomes in the representation expected after the pass and returns corrections that are applied in the updated quantum context. No internal inspection or rewriting of the callback occurs; the wrapper supplies the adapted inputs and interprets the outputs according to the new abstraction level. We have added a concrete worked example of a simple syndrome-feedback loop under ISA translation to the revised manuscript to illustrate that the classical logic executes unchanged while the surrounding quantum operations are adapted.","revision_made":"yes","referee_comment":"[Framework description] Framework description (callback-wrapping mechanism): because callbacks are treated as black boxes written in arbitrary classical languages, the paper does not address how an earlier pass (e.g., ISA translation) could alter the effective hybrid program without inspecting or modifying callback internals. This assumption is load-bearing for the compositional claim yet receives no concrete test or counter-example analysis."}],"tokens_in":1479,"tokens_out":513,"duration_ms":54022,"standing_objections":[]},"desk_editor":{"model":"grok-4.3","letter":"The main point is that this paper gives a concrete way to make quantum error correction passes compositional inside a compiler. By putting everything in a purely quantum IR and hiding classical feedback behind opaque callbacks, each pass can adapt both the quantum ops and the callbacks without manual rewriting. They show this working for stacking repetition codes into Shor code, plus Steane, all the way down to trapped-ion instructions. That addresses a real pain point where people currently have to hand-tune the classical control logic at every layer.","headline":"qstack's opaque callback wrapping lets compiler passes compose QEC layers automatically, but the lack of semantic proofs leaves the hybrid correctness claim mostly unverified.","tokens_in":2292,"tokens_out":176,"would_cite":false,"duration_ms":27237,"reading_group":"maybe","serious_thinker":"yes","would_accept_peer_review":true},"rs_alignment":{"model":"grok-4.3","evidence":[],"headline":"qstack's callback-wrapping compilation for hybrid QEC programs shares no machinery with RS forcing from distinction","alignment":"orthogonal","rationale":"The paper's core is an IR with opaque callbacks plus wrapping adapters that decode measurements and recursively compile returned kernels, enabling composable ISA/QEC passes (e.g., repetition codes to Shor). This is standard compiler engineering for hybrid semantics. RS derives J-cost, φ, 8-tick periodicity, D=3, and constants from a single distinction (reality_from_one_distinction, AbsoluteFloorClosure, Cost.FunctionalEquation). No overlap in structure, cost functions, periodicity, or parameter-free derivations; domain is quantum compilation, not foundational physics.","tokens_in":51197,"confidence":"high","tokens_out":164,"duration_ms":14340,"cache_read_input_tokens":128,"cache_creation_input_tokens":0},"lean_confirmation":null,"pith_extraction":{"msc":[],"pacs":[],"model":"grok-4.3","headline":"qstack enables compositional end-to-end compilation for fault-tolerant quantum programs by wrapping classical callbacks.","keywords":["quantum compilation","fault-tolerant quantum computing","quantum error correction","compiler framework","hybrid quantum-classical programs","opaque callbacks","compositional compilation"],"falsifier":"A concrete quantum program with classical feedback where a compilation pass changes observable behavior unless the callback internals are inspected or rewritten by hand.","tokens_in":2598,"feed_emoji":"⚛️","tokens_out":610,"duration_ms":60520,"temperature":0.7,"pith_summary":"The paper presents qstack, a compiler framework that incorporates quantum error correction directly into the compilation pipeline for quantum programs. It introduces a purely quantum intermediate representation that treats classical feedback logic from syndrome measurements as opaque callbacks written in any classical language. The central mechanism is callback wrapping, which automatically adapts both quantum operations and the associated classical callbacks during each compiler pass. Any kernel that a callback dynamically generates is itself run through the full compilation pipeline. This design allows passes for different error-correcting codes to be composed without manual rewriting of classical logic, as shown by end-to-end compilation from high-level gates through Clifford gates to trapped-ion native instructions using repetition codes, the Steane code, and the Shor code.","feed_headline":"Callback wrapping composes quantum error-correction passes","feed_subtitle":"qstack adapts classical feedback automatically so Steane and Shor codes emerge from repetition passes without manual changes.","key_machinery":"Callback wrapping, which automatically adapts both quantum operations and their associated classical callbacks while routing dynamically generated kernels through the full pipeline.","core_discovery":"qstack's callback wrapping mechanism enables each compiler pass to automatically adapt quantum operations and their associated classical callbacks, with any kernel dynamically generated by a callback also compiled through the full pipeline, allowing ISA translation and quantum error correction to be expressed as composable passes including code concatenation.","pith_inferences":["This wrapping approach could reduce the effort required to add support for new hardware targets or error-correcting codes.","The technique may generalize to other hybrid quantum-classical compilation tasks that involve runtime feedback.","Limits may appear when classical callbacks contain complex state that interacts with quantum measurements in ways opaque access cannot capture."],"forward_implications":["ISA translation and quantum error correction can be expressed as composable compiler passes.","Concatenation of error-correcting codes such as repetition codes yielding Steane and Shor codes occurs without manual intervention.","End-to-end compilation from a high-level gate set through Clifford gates to trapped-ion native operations is achieved.","Any kernel dynamically generated by a callback is compiled through the full pipeline."],"fun_headline_variants":["qstack composes quantum error-correction passes with callback wrapping","Callback wrapping automates quantum-classical code adaptation","Composable compiler passes for Steane and Shor codes","qstack enables end-to-end fault-tolerant quantum compilation"],"cache_read_input_tokens":64,"weakest_assumption_plain":"That classical logic accessed only through opaque callbacks preserves full program semantics across all compilation stages without requiring inspection or modification of the callback internals.","fun_headline_variants_meta":{"raw":{"variants":["qstack composes quantum error-correction passes with callback wrapping","Callback wrapping automates quantum-classical code adaptation","Composable compiler passes for Steane and Shor codes","qstack enables end-to-end fault-tolerant quantum compilation"]},"model":"grok-4.3","cost_usd":0.012533,"raw_usage":{"total_tokens":5360,"prompt_tokens":640,"num_sources_used":0,"completion_tokens":54,"cost_in_usd_ticks":125328000,"prompt_tokens_details":{"text_tokens":640,"audio_tokens":0,"image_tokens":0,"cached_tokens":64},"completion_tokens_details":{"audio_tokens":0,"reasoning_tokens":4666,"accepted_prediction_tokens":0,"rejected_prediction_tokens":0}},"tokens_in":640,"tokens_out":54,"duration_ms":83658,"temperature":1.0,"reasoning_tokens":4666,"cache_read_input_tokens":64,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-05-20T18:15:25.373310+00:00","model_set":{"reader":"grok-4.3"},"falsifier":"A concrete quantum program with classical feedback where a compilation pass changes observable behavior unless the callback internals are inspected or rewritten by hand.","supporting_citations":[],"review_version":1}