This was last updated in September 2014. It may be out of date. If you want me to update it or have any questions, please contact me by email at: sabre@nondot.org.

Chris Lattner

My overall objective is to improve large software systems through the development of novel techniques as well as the application of known engineering principles. Of particular interest to me are programming languages, compilers, debuggers, operating systems, graphics, and other system software.

I am the founder and chief architect of the open source LLVM Compiler Infrastructure project. The LLVM project is an umbrella project which has grown to include a broad range of compiler, debugger, and runtime library technology. Assembled out of this technology are things like the Clang compiler, the LLDB debugger, the Clang Static Analyzer, and other low-level tools. LLVM is widely used for academic research projects, has been adopted for commercial use by several companies, and has a broad and growing developer base. For more information, please see the LLVM web page: http://llvm.org/.

Beyond my work on the LLVM project, I am the Senior Director of the Developer Tools department at Apple. My role at Apple is to drive innovation in the programming tools space, as well as manage Apple's developer tools products (i.e., Xcode, and Instruments, along with a variety of low-level toolchain components) for both OS X and iOS. Developer tools serve a key function that enables all software that Apple ships, as well as powering the iOS and Mac OS app stores.

I am a strong leader and have excellent communication skills (both verbal and written). I occasionally give talks explaining and evangelizing LLVM, Clang, and other technologies in the llvm.org umbrella.

Resume Contents:

• Awards
• Book Chapter
• Work History
• Education
• Refereed Publications
• Invited Talks
• Dissertations & Technical Reports
• Other Interests and Activities

Awards

Notable awards:

• I was awarded the 2013 Distinguished Alumni Achievement Award by the University of Illinois Computer Science Department.
• LLVM was awarded the ACM Software Systems Award which recognizes a software system that has had a lasting influence, reflected in contributions to concepts, in commercial acceptance, or both (across the entire software industry). Previous recipients include Java, Apache, the World-Wide Web, SMALLTALK, UNIX, and many other notable software systems.
• LLVM was awarded the ACM SIGPLAN Programming Languages Software Award in 2010 in recognition of my work on LLVM. SIGPLAN is the ACM Organization focusing on Programming Language Design and Implementation. Being the first year this was awarded is notable, because all programming language software systems were eligible. I am very thankful for the honor.

Book Chapter

In 2011, I wrote a chapter on LLVM for "The Architecture of Open Source Applications," a book on software design. The chapter describes traditional compiler design, what makes LLVM different, how library-based design impacts applicability of the code, and how some simple optimizations work.

Work History

Apple Inc

• Apple Inc: Developer Tools Department
  Senior Director and Architect, Developer Tools Department
  January 2013 - Ongoing

  In January 2013, I took over management and leadership of the entire Developer Tools department at Apple (> 100 people). In addition to languages (Swift and Objective-C), compilers and low-level tools, I took on responsibility for the Xcode IDE, Instruments performance analysis tool, Apple Java releases, and a variety of internal tools.

  In this time period, my team shipped a number of major Xcode releases, including Xcode 4.6, 5.0, 5.1, 6.0 and 6.1, each with major feature enhancements. Some of my more notable contributions include:

  • ARM64: Over a 3 year span, I drove definition, bringup and implementation work of the ARM64 (aka Aarch64) compiler toolchain - the first production quality compiler for this architecture in the world - which shipped in Xcode 5. This enabled the iPhone 5s, which shocked the world with its 64-bit support and superb performance. In addition to compiler work, I contributed to the design of a new Objective-C runtime object model for the architecture, and I personally contributed the "TBI" feature to ARM, which was incorporated in the Aarch64 architecture.
  • iPhone GPU Compiler: we implemented a completely new LLVM-based runtime GPU shader compiler. This started shipping in iOS7 to support the iPhone 5s - which featured a VLIW PowerVR Rogue GPU derivative, and has been extended to support later iPhone hardware as it comes out. Compared to the vendor compiler it replaced, this GPU compiler produces code that runs slightly faster, and takes much less compile time to generate it.
  • Xcode 5 was a major release, notable for me in that it was the first release with a completely LLVM-based low-level toolchain (Clang, LLDB, etc) - it dropped the last support for GCC and GDB. This transition was largely driven by the ARM64 architecture transition.
  • Xcode 5.1 was the first major release that I drove end-to-end as lead of the developer tools group.
  • Swift: The most prominent feature of Xcode 6 was Swift, a new programming language that I had been personally driving since 2010. In addition to the language design and implementation, I drove much of the compiler architecture (e.g. the SIL high-level IR), the REPL and Playgrounds feature designs, drove and coordinated the rest of the team to implement full Xcode and documentation support for a language that was still rapidly evolving. We managed to keep extremely tight secrecy until a great launch at WWDC 2014.
  • I was the primary proponent for the Official Swift Blog and wrote many of the posts.

  When more of my contributions in this timeframe become public, I will elaborate.

• Apple Inc: Developer Tools Group
  Director and Architect, Low-Level Tools
  September 2011 - January 2013

  This timeframe has included numerous technical and team achievements across a wide range of domains. For example:

  • Apple shipped the Mac OS X 10.8 and iOS 6 releases, and they were built with Clang - llvm-gcc is obsolete, and GCC is long gone.
  • We invested major effort into compiler implementation and tuning for the custom Apple CPU design known as the "Apple A6". The exceptional CPU performance of the iPhone 5 was a result of a joint effort between the Apple silicon and LLVM teams.
  • I personally drove LLDB to production quality and to become the default debugger in Xcode.
  • I drove the new "Objective-C Literal Syntax" language extensions, making many common situations in Objective-C much more syntactically elegant.
  • We shipped Xcode 4.3, 4.4, and 4.5 releases, and I was a key part of the high level feature planning and decision processes that defined the features and shaped the releases.

• Apple Inc: Developer Tools Group
  Senior Manager and Architect, Low-Level Tools
  June 2010 - September 2011

  I managed the teams responsible for compilers, the LLDB debugger, Objective-C and C++ runtimes, assembler, linker, dynamic loader, etc. I am continuing my work improving the Apple developer tools, and continue to contribute daily to the open source LLVM technologies. During this time period my team switched Mac OS/X Lion and iOS5 to build with llvm-gcc and clang (off of GCC 4.2) and oversaw the final release of Xcode 4.0 in March (as well as subsequent updates).

  Xcode 4.2 was a specific achievement in that it is the first release where all of its compilers are LLVM-based (GCC 4.2 is no longer included). Xcode 4.2 also includes the "Automatic Reference Counting (ARC) Objective-C language feature (see also wikipedia). ARC has revolutionized Objective-C programming by automating memory management without the runtime overhead of a garbage collector. I personally defined and drove this feature late in the schedule of iOS5 and Lion. This is notable for the short schedule for the project, the extensive cross-functional work required, and the extensive backwards compatibility issues that had to be addressed (making it a very technically complex problem).

• Apple Inc: Developer Tools Group
  Senior Manager of Compilers and Low-Level Tools, Compiler Architect
  September 2009 - June 2010

  My work in this time period culminated in the release of the Xcode 4 preview at WWDC, which included a preview release of Clang C++ support, a new C++ Standard Library, a much faster and memory efficient system linker, a new X86 assembler (which is integrated into the clang compiler, providing faster compile times), and countless smaller improvements throughout the toolchain.

  Xcode 4 itself now features deep integration of the Clang parser for code completion, syntax highlighting, indexing, live warning and error messages, and the new 'Fix-It' feature in which the compiler informs the UI how to automatically corrects small errors. LLVM-GCC is the default compiler in Xcode 4.

  The Xcode 4 preview also includes the first public release of LLDB to which I served as a consultant and contributed directly to turning it into an open source project.

• Apple Inc: Developer Tools Group
  Manager of Compilers and Low-Level Tools, Compiler Architect
  July 2008 - September 2009

  In this time period, I was a second level manager running the teams responsible for Clang, LLVM, GCC, and other parts of the Apple toolchain (assembler, linker, etc). I directly managed the Clang team, contributed daily to both the Clang and LLVM projects, and continued in my role as compiler architect and lead on the Open Source LLVM/Clang projects.

  During this period my team brought Clang 1.0 to production quality as a brand new C and Objective-C compiler for X86-32 and X86-64. We also productized and shipped the Xcode static analyzer, a new compiler-rt library (which replaced libgcc in Snow Leopard) and many enhancements to existing components in the operating system.

• Apple Inc: Developer Tools Group
  LLVM Compiler Group Manager and Compiler Architect
  December 2006 - July 2008

  In this time period, my group expanded use of LLVM within Apple, supported new clients, built new features, and extended LLVM in many ways. We shipped llvm-gcc 4.2 in the Xcode 3.1 and major improvements for it in the Xcode 3.1.1 release.

  In addition to llvm-gcc, much of the work during this time was focused on Mac OS 10.6 development. I made major contributions to design and implementation of the "Blocks" language feature as well as to the architecture and design of the language and compiler aspects of the OpenCL GPGPU technology.

  Finally, during this period I architected and started implementation of a suite of front-end technlogies based on LLVM, named "Clang".

• Apple Computer Inc: Developer Tools Group
  Senior Compiler Engineer and Tech Lead
  June 2005 - December 2006

  I drove LLVM productization, features and applications at Apple. LLVM link-time optimization support is now integrated into the Apple system linker, and LLVM is used by the Apple OpenGL group for several different purposes. My main contributions during this time was a new llvm-gcc4 front-end, significant improvements to the X86 and PowerPC backends, a wide range of optimization improvements and new optimizers, significant improvement to the target-independent code generator, and leadership for the rest of the team.

Graduate School Work

• University of Illinois at Urbana Champaign
  Research Assistant
  Fall 2000 - Spring 2005

  I worked on numerous projects at UIUC, the most important being LLVM and Data Structure Analysis (DSA). At Illinois, I designed and built most of the fundamental aspects of LLVM, establishing the architecture for things to come and building most of the scalar, loop and interprocedural optimizers. I also built most of the target-independent code generator, X86 backend, JIT, llvm-gcc3 front-end, and much more. Finally, I wrote many papers.

• Microsoft Research: Programmer Productivity Research Center
  Research Intern
  Summer 2004

  I worked on the Microsoft Phoenix compiler infrastructure, building an experimental bridge between the Microsoft compiler and the LLVM compiler (which allowed LLVM to compile and run .NET code). In the process, I identified and fixed numerous bugs in the (still in early development) Microsoft compiler.

IBM NUMA-Q / Sequent Computer Systems:

• Operating Systems Group
  Software Engineer Contractor
  May '00 - Aug '00

  I virtualized the Linux Kernel to run as a user-level application under the Dynix/PTX operating system. This provided 100% compatibility with existing Linux binaries, but this project was never productized.

• Compilers & Tools Group
  Software Engineer Contractor
  May '99 - Dec '99

  I was involved with the 4.5 release of Sequent's PTX OS, which added kernel threads. I was primarily involved porting the Java Virtual Machine from user-level threads to native threads, but was also drive debugged many kernel issues in the pthreads implementation. I also added thread awareness to the system debugger.

• Operating Systems Group
  Software Engineer Intern
  Jan '99 - Apr '99

  I worked 16 hrs/wk developing an online remote kernel debugger based on GDB.

• Compilers & Tools Group
  Software Engineer Intern
  May-Aug, Dec '98

  My primary work was to port Sun's Java Virtual Machine to the Dynix/PTX OS. This involved work in both C & Java, in systems as varied as user-level threads, garbage collection, and asynchronous I/O.

Education

University of Illinois, Urbana-Champaign - Urbana, Illinois - GPA: 4.0

• Ph.D. Computer Science: Spring 2002 - Spring 2005
  Thesis: "Macroscopic Data Structure Analysis and Optimization"
• M.S. Computer Science: Fall 2000 - Fall 2002
  Thesis: "LLVM: An Infrastructure for Multi-Stage Optimization"

University of Portland - Portland, Oregon - GPA: 3.9

• B.S. Computer Science: Fall 1996 - Spring 2000

Refereed Publications

Since joining industry, I rarely take time to write papers about my work, preferring instead to focus on building new great things. That said, LLVM is widely used as a basis for many current and past research projects by other people.

1. "Making Context-sensitive Points-to Analysis with Heap Cloning Practical For The Real World"
   Chris Lattner, Andrew Lenharth, and Vikram Adve
   PLDI 2007, San Diego, CA, June 2007
2. "Automatic Pool Allocation: Improving Performance by Controlling Data Structure Layout in the Heap"
   Chris Lattner & Vikram Adve
   PLDI 2005, Chicago, IL, June 2005.
   Awarded PLDI 2005 Best Paper Award
3. "Automatic Pointer Compression for Linked Data Structures"
   Chris Lattner & Vikram Adve
   ACM SIGPLAN 2005 Workshop on Memory System Performance (MSP'05) Chicago, IL, June 2005.
4. "Memory Safety Without Runtime Checks or Garbage Collection"
   Dinakar Dhurjati, Sumant Kowshik, Vikram Adve & Chris Lattner
   2005 Transactions in Embedded Computing Systems (TECS'05)
   Journal Publication
5. "The LLVM Compiler Framework and Infrastructure Tutorial"
   Chris Lattner & Vikram Adve
   LCPC'04 Workshop on Compiler Research Infrastructures, West Lafayette, Indiana, Sep. 2004.
6. "LLVM: An Aggressive Compilation Framework for Life-Long Program Analysis and Transformation"
   Chris Lattner & Vikram Adve
   CGO 2004, San Jose, CA, March 2004.
   Best Student Presenter Award
   Test of Time Award for the most influential paper of CGO 2004 (awarded at CGO 2014).
7. "LLVA: A Low-level Virtual Instruction Set Architecture"
   Vikram Adve, Chris Lattner, Michael Brukman, Anand Shukla, & Brian Gaeke
   MICRO-36 2003, San Diego, CA, December 2003.
8. "Memory Safety Without Runtime Checks or Garbage Collection"
   Dinakar Dhurjati, Sumant Kowshik, Vikram Adve, & Chris Lattner
   Proc. Languages Compilers and Tools for Embedded Systems 2003 (LCTES 03), San Diego, CA, June 2003.
9. "Architecture For a Next-Generation GCC"
   Chris Lattner & Vikram Adve
   First Annual GCC Developers' Summit, Ottawa, Canada, May 2003.
10. "Automatic Pool Allocation for Disjoint Data Structures"
    Chris Lattner & Vikram Adve
    ACM SIGPLAN 2002 Workshop on Memory System Performance (MSP'02), Berlin, Germany, June 2002.
11. "Developing a Graphical Robotics Simulator"
    Ming-Shu Hsu & Chris Lattner
    IASTED International Conference, Modeling & Simulation (MS'99)

Invited Talks

1. "LLVM - The Early Days - first half of a talk
   2013 LLVM Developer's Meeting, San Francisco, CA, November 2013.
2. "LLVM and Clang - Advancing Compilers and Tools
   Opening Keynote, 2013 Central and Eastern European Software Engineering Conference in Russia (CEE-SECR 2013), Moscow, Russia, October 2013.
   Selected as the best invited talk by conference attendees.
3. "Developer Tools Kickoff" (shared talk)
   2012 Apple World Wide Developer Conference (WWDC), San Francisco, CA, June 2012.
4. "Increasing Industry Impact of Compiler Optimization Research"
   Opening Keynote, 2012 International Symposium on Code Generation and Optimization (CGO'12), San Jose, CA, April 2012.
5. "LLVM and Clang: Advancing Compiler Technology
   Keynote, Free and Open Source Developers' European Meeting (FOSDEM'11), Brussels, Belgium, February 2011.
6. "What's New in the LLVM Compiler" (shared talk)
   2010 Apple World Wide Developer Conference (WWDC), San Francisco, CA, June 2010.
7. "State of Clang" (shared talk) and several other pieces of the meeting, such as the introduction, open discussion forum, etc.
   LLVM Developer Meeting, Cupertino, CA, Oct 2009.
8. "Developer Tools State of the Union" (shared talk)
   2009 Apple World Wide Developer Conference (WWDC), San Francisco, CA, June 2009.
9. "Compiler State of the Union" (shared talk)
   2009 Apple World Wide Developer Conference (WWDC), San Francisco, CA, June 2009.
10. "Introduction to the LLVM Compiler System"
    Plenary Talk, ACAT 2008: Advanced Computing and Analysis Techniques in Physics Research, Erice, Sicily, Italy, November 2008.
11. "Compiler State of the Union" (shared talk)
    2008 Apple World Wide Developer Conference (WWDC), San Francisco, CA, June 2008.
12. "LLVM Compiler In Depth" (shared talk)
    2008 Apple World Wide Developer Conference (WWDC), San Francisco, CA, June 2008.
13. "LLVM and Clang: Next Generation Compiler Technology"
    BSDCan 2008, Ottawa, Canada, May 16-17, 2008.
14. "The LLVM Compiler System"
    2007 O'Reilly Open Source Convention, Portland, OR, July 2007.
15. "LLVM 2.0 and Beyond!"
    Google Tech Talk, Mountain View, CA, July 25, 2007.
16. "Taking Advantage of Compiler Advances" (shared talk)
    2007 Apple World Wide Developer Conference (WWDC), San Francisco, CA, June 2007.
17. "LLVM in OpenGL and for Dynamic Languages" (and several others)
    LLVM Developer Meeting, Cupertino, CA, May 2007.
18. "The LLVM Compiler System"
    2007 Bossa Conference on Open Source, Mobile Internet and Multimedia, Recife, Brazil, March 2007.
19. "Introduction to the LLVM Compiler Infrastructure"
    2006 Itanium Conference and Expo, San Jose, California, April 2006.

Dissertations & Technical Reports

1. "Macroscopic Data Structure Analysis and Optimization"
   Chris Lattner. Ph.D. Thesis, May 2005
2. "LLVM: A Compilation Framework for Lifelong Program Analysis & Transformation"
   Chris Lattner & Vikram Adve
   University of Illinois Technical Report #UIUCDCS-R-2003-2380, Sep 2003
3. "Data Structure Analysis: An Efficient Context-Sensitive Heap Analysis"
   Chris Lattner & Vikram Adve
   University of Illinois Technical Report #UIUCDCS-R-2003-2340, Apr 2003
4. "LLVM: An Infrastructure for Multi-Stage Optimization"
   Chris Lattner. Masters Thesis, Dec. 2002
5. "The LLVM Instruction Set and Compilation Strategy"
   Chris Lattner & Vikram Adve
   Univ. of Illinois Technical Report #UIUCDCS-R-2002-2292, Aug 2002

Other Interests and Activities

• In addition to technical activities:
  • I enjoy woodworking, downhill skiing, swimming, and walking our dogs.
  • I was a competitive fencer and was president of the University of Illinois Classical Fencing club.
  • I taught an introduction to fencing class in Fall 2003, with a class of ~15 people. I continued the training of this class through Fall 2004.