Sync 2026 EuroLLVM Developers' Meeting

content/devmtg/2026-04.md

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+---
+title: "2026 EuroLLVM Developers' Meeting"
+description: ""
+date: 2026-04-13T19:45:19+05:30
+toc: true
+tags: []
+draft: false
+---
+
+{{< event_data "2026-04" >}}
+
+## About
+
+The EuroLLVM Developers' Meeting is a gathering of the entire LLVM Project
+community. The conference is organized by the LLVM Foundation and volunteers
+within the LLVM community. Developers and users of LLVM, Clang, and related
+subprojects attend talks, impromptu discussions, and networking sessions.
+
+### What can you expect at an LLVM Developers' Meeting?
+
+- **Keynotes** are 40-45 minute talks that provide an overview of a topic or
+  project and often capture its history and impact.
+- **Technical Talks** are 20-30 minute sessions covering core infrastructure,
+  LLVM subprojects, and uses of LLVM in academia and industry.
+- **Tutorials** are 50-60 minute sessions that explore a technical topic in
+  depth, with examples and explanations.
+- **Lightning Talks** are fast 5 minute introductions to a project or topic.
+- **Quick Talks** are 10 minute talks that go deeper than a lightning talk.
+- **Student Technical Talks** let graduate and undergraduate students present
+  their work using LLVM.
+- **Panels** are guided discussions with developers and audience questions.
+
+### Who attends?
+
+- Active developers of projects in the LLVM umbrella.
+- Anyone interested in using LLVM projects as part of another project.
+- Students and researchers.
+- Compiler, programming language, and runtime enthusiasts.
+- Sponsors and partners using LLVM technology in their products.
+
+For future announcements or questions, visit the
+[LLVM Discourse forums](https://discourse.llvm.org/) and the
+[eurollvm tag](https://discourse.llvm.org/tag/eurollvm).
+
+## Program
+
+### Keynotes
+
+{{< event_talks
+    "devmtg/2026-04/keynote"
+    "keynote"
+>}}
+
+### Technical Talks
+
+{{< event_talks
+    "devmtg/2026-04/technical_talks"
+    "technical_talks"
+>}}
+
+### Tutorials
+
+{{< event_talks
+    "devmtg/2026-04/tutorials"
+    "tutorials"
+>}}
+
+### Quick Talks
+
+{{< event_talks
+    "devmtg/2026-04/quick_talks"
+    "quick_talks"
+>}}
+
+### Lightning Talks
+
+{{< event_talks
+    "devmtg/2026-04/lightning_talks"
+    "lightning_talks"
+>}}
+
+### Student Technical Talks
+
+{{< event_talks
+    "devmtg/2026-04/student_technical_talks"
+    "student_technical_talks"
+>}}
+
+### Panels
+
+{{< event_talks
+    "devmtg/2026-04/panels"
+    "panels"
+>}}
+
+### Posters
+
+{{< event_posters
+    "devmtg/2026-04/posters"
+    "posters"
+>}}
+
+### MLIR Workshop
+
+{{< event_talks
+    "devmtg/2026-04/mlir_workshop"
+    "mlir_workshop"
+>}}
+
+## Code of Conduct
+
+The LLVM Foundation is dedicated to providing an inclusive and safe experience
+for everyone. We do not tolerate harassment of participants in any form. By
+registering for this event, attendees agree to the
+[LLVM Code of Conduct](https://llvm.org/docs/CodeOfConduct.html).
+
+## Contact
+
+To contact the organizer, email [events@llvm.org](mailto:events@llvm.org).

data/devmtg/2026-04/keynote.yml

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+keynote:
+  - title: "Capabilities Great and Small: CHERI, CHERIoT, and LLVM"
+    speaker: "Owen Anderson, presented by Edoardo Marangoni, Q&A featuring Owen Anderson and David Chisnall"
+    video_url: ""
+    slides_url: "/devmtg/2026-04/slides/keynote/keynote_anderson.pdf"
+    description: |
+      Support for the CHERI capability architecture and its embedded derivative, CHERIoT, is being
+      upstreamed to LLVM. This talk explores what that means for LLVM developers, which parts of the
+      toolchain are affected, and how these changes may interact with existing frontend, optimizer,
+      backend, and linker work. We’ll take a look at work to date, the status of upstreaming, and open
+      problems where community involvement could help.
+
+  - title: "Keynote: The Testing Funnel: Validating LLVM at Scale"
+    speaker: "Reid Kleckner"
+    video_url: ""
+    slides_url: "/devmtg/2026-04/slides/keynote/keynote_kleckner.pdf"
+    description: |
+      LLVM is foundational software, so stakes for making changes to it are very high, and most
+      downstream vendors of LLVM have elaborate testing pipelines to validate all of the properties they
+      care about. However, because these private pipelines are often slow and disconnected from the
+      community, detecting defects is expensive and leads to labor-intensive negotiations over
+      misaligned technical requirements. To improve the experience for both contributors and
+      downstreams, this talk shares lessons from 15 years of LLVM continuous integration experience to
+      advocate for shared upstream CI infrastructure that "shifts left" on testing, to create a better,
+      more harmonious experience for contributors and consumers alike.

data/devmtg/2026-04/lightning_talks.yml

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+lightning_talks:
+  - title: "Using MLIR Linalg Category Ops for Smarter Compilation"
+    speaker: "Javed Absar"
+    video_url: ""
+    slides_url: "/devmtg/2026-04/slides/lightning_talk/lightning_talk_absar.pdf"
+    description: |
+      Linalg dialect of MLIR recently added `category ops` as an intermediate abstraction between the
+      two existing forms: named ops and generic ops. A mechanism (-linalg-morph-ops=_-to-_) to move
+      between these forms was also introduced. When something new appears, adoption is often slow due to
+      existing workflows and lack of awareness.
+      This talk will:
+      (a) Motivate the reason for this additional representation
+      (b) Explain what now exists and how to benefit from it
+      (c) Show how category ops can help certain compilation flows.
+
+  - title: "Highlighting function names in LLDB backtraces"
+    speaker: "Michael Buch"
+    video_url: ""
+    slides_url: "/devmtg/2026-04/slides/lightning_talk/lightning_talk_buch.pdf"
+    description: |
+      C++ backtraces tend to be hard to read because function names are hidden amongst many layers of
+      namespaces, template arguments and function parameters. In the debugger, a user often wants to
+      simply get a quick overview of the function callstack. But traditionally this has been difficult
+      to decipher. To improve readability, LLDB recently gained the ability to selectively hide or
+      format various parts of C++ function names. This talk describes how we implemented this by
+      extending the LLVM demangler and how other language plugins can take advantage of this
+      infrastructure.
+
+  - title: "Engineering a Hybrid Rust and MLIR Toolchain for AI Agents"
+    speaker: "Miguel Cárdenas"
+    video_url: ""
+    slides_url: "/devmtg/2026-04/slides/lightning_talk/lightning_talk_cardenas.pdf"
+    description: |
+      Developing a compiler for Agentic AI workloads presents a unique challenge because the runtime
+      demands the safety and ergonomics of Rust while the optimization pipeline requires the mature
+      infrastructure of MLIR. This talk presents the architecture of a toolchain designed to leverage
+      the strengths of both ecosystems. We discuss how we structured a hybrid build system where Rust
+      drives the compilation process and defines runtime semantics, while C++ manages the core MLIR
+      dialect and transformations. The session covers the practical engineering required to bridge these
+      worlds, from orchestrating CMake and Cargo to managing the boundary between Rust runtime metadata
+      and MLIR operation definitions. We share lessons learned about the complexity of linking, the
+      tradeoffs of code generation, and the reality of maintaining a custom dialect across the language
+      barrier.
+
+  - title: "Compact Unwind Information for ELF"
+    speaker: "Alexis Engelke"
+    video_url: ""
+    slides_url: "/devmtg/2026-04/slides/lightning_talk/lightning_talk_engelke.pdf"
+    description: |
+      ELF unwind information is encoded as DWARF bytecode for most architectures, which results in a
+      large size overhead and is complex to interpret, precluding its use in e.g. tracing profilers.
+      This talk will present a compact format for asynchronous unwind info that can accurately represent
+      almost all functions generated by LLVM -O3 for x86-64 with a substantially smaller size. We will
+      also discuss portability to other architectures, differences from other unwinding/tracing formats,
+      and interoperability with other toolchains.
+
+  - title: "Coverage directed codebase reduction for the procedural generation of LIT tests"
+    speaker: "Freya Fewtrell"
+    video_url: ""
+    slides_url: "/devmtg/2026-04/slides/lightning_talk/lightning_talk_fewtrell.pdf"
+    description: |
+      The LIT test suite, whilst extensive, still leaves many parts of the LLVM codebase uncovered.
+      Compiling large real-world C++ code from Sony Interactive Entertainment’s downstream integration
+      test suite routinely exercises code paths that the upstream LIT suite never reaches. To shift this
+      testing leftwards, we have built a tool that uses coverage-directed reduction to automatically
+      turn such high-coverage sources into minimal, self-contained LLVM IR fragments suitable for
+      inclusion as upstream LIT tests. This lightning talk describes how the tool works, the challenges
+      encountered when trying to automate test reduction at scale, and whether increasing coverage alone
+      is sufficient motivation for new upstream LIT tests.
+
+  - title: "Improving DemandedBits Analysis for Shift Operations in LLVM"
+    speaker: "Panagiotis Karouzakis"
+    video_url: ""
+    slides_url: "/devmtg/2026-04/slides/lightning_talk/lightning_talk_karouzakis.pdf"
+    description: |
+      The DemandedBits analysis is utilized in some optimization passes, such as vectorization and dead
+      code elimination; a similar analysis is employed in InstCombine. We improve DemandedBits reasoning
+      for all basic shift operations, enabling more precise bit-level information propagation. Our
+      improvements reduced code size, enabled additional loop-invariant code motion, and lead to more
+      instruction-level simplifications.
+
+  - title: "STRTAB Hash & Slash: Reducing STRTAB size by hashing its entries"
+    speaker: "Vy Nguyen"
+    video_url: ""
+    slides_url: "/devmtg/2026-04/slides/lightning_talk/lightning_talk_nguyen.pdf"
+    description: |
+      The string table(STRTAB) accounts for a significant portion of object file overhead at Google,
+      with long mangled names, such as those from Protos, frequently reaching 35% of the total file
+      size. Optimizing this space is the key to faster builds and leaner binaries. In this talk, we
+      propose an approach to reduce the string table through hashing its entries, demonstrating a
+      reduction in overall binary size
+
+  - title: "Extending Lifetime Safety: Verification of [[clang:noescape]] annotation"
+    speaker: "Abhinav Pradeep"
+    video_url: ""
+    slides_url: "/devmtg/2026-04/slides/lightning_talk/lightning_talk_pradeep.pdf"
+    description: |
+      Clang features an intra-procedural, flow-sensitive lifetime analysis designed to catch temporal
+      safety errors like use-after-free, use-after-scope, and use-after-return. The talk presents work
+      on leveraging this analysis to verify [[clang::noescape]] annotations. This effort focuses on
+      applying the "Origins and Loans" model to enforce memory safety guarantees that were previously
+      unverified by the compiler.
+
+  - title: "Reproducible Large-Workload Recipes for BOLT with Nixpkgs"
+    speaker: "Peter Waller"
+    video_url: ""
+    slides_url: "/devmtg/2026-04/slides/lightning_talk/lightning_talk_waller.pdf"
+    description: |
+      BOLT needs large, realistic binaries for integration testing, but distributing binaries directly
+      creates governance and supply-chain problems and makes it hard to reproduce the exact toolchains
+      and build flags that shape BOLT behaviour. We show our pinned, auditable Nixpkgs build recipes
+      (including emit-relocs Chromium) and discuss how this enables teams to reproduce identical
+      workloads, generate provenance/SBOMs, and compare results consistently across machines and CI.
+
+  - title: "What’s new in LLDB on Windows"
+    speaker: "Charles Zablit"
+    video_url: ""
+    slides_url: "/devmtg/2026-04/slides/lightning_talk/lightning_talk_zablit.pdf"
+    description: |
+      We've been improving LLDB and LLDB-DAP on Windows, adding key features like STDIO support, Unicode
+      handling, better Python integration, and switching to an open-source PDB implementation to bring
+      Windows debugging up to par with other platforms.