[LLVMdev] Google SOC - Idea

[me22]

Some initial thoughts:
- Your abstract is almost half as long as the full proposal, so you
might want to move some of its content into the detailed description.
- Error on the side of being too formal.  I doubt "stuffy",
"ridiculous", and "shit" will do much to help you.

~ Scott McMurray

P.S. How many Scotts are there on this list, anyways? :P

On 3/19/07, Scott Fortmann-Roe <scottfr at gmail.com> wrote:
> Hi,
>
> Here is a rough draft of the application -- a FORTRAN front-end to
> LLVM. In accordance with the summer of code specifications it is split
> into two portions: the abstract which describes the project, and the
> details description which describes me and how I plan to complete the
> project.
>
> It's a little long, (but about half the max length the application
> directions specify). Would someone be willing to read it in full
> (Chris?, Kenneth?) and see if the project as specified would really be
> useful to LLVM and something you guys would support?
>
> I will submit the application on the 23rd of March, so if anyone would
> like to offer feedback or suggest changes to the direction of the
> project, please email them to me before then.
>
> Cheers,
> Scott
>
> ABSTRACT
> ----------------
>
> The purpose of this project is to develop a FORTRAN front-end to the
> Low Level Virtual Machine (LLVM) compiler infrastructure. LLVM is a
> mature collection of tools which provide a powerful resource for
> language developers and end-user programmers. LLVM consists of roughly
> three components. The first is a front-end to a language (such as C,
> C++, or virtually any other) that parsers the language and converts it
> into LLVM's Intermediate Representation (IR). The LLVM IR is a
> language- and target- independent representation. The next component
> of LLVM is a collection of powerful optimization routines that operate
> on the IR. The final module of LLVM is a backend that can compile
> optimized code to a number of platforms including x86 and PowerPC, can
> emit an optimized C representation of the original program, or use a
> Just-In-Time compiler to interpret the program on a variety of
> platforms.
>
> To claim FORTRAN is mature is an understatement. In use for over 50
> years, FORTRAN is utilized in a wide variety of legacy code bases.
> While younger and flashier languages get all the press, FORTAN still
> enjoys wide usage in many scientific fields and other
> businesses—especially when legacy code is involved.
>
> The implementation of a FORTAN front end would benefit both the
> FORTRAN user-base and the LLMV project. The scientific uses of
> FORTRAN—along with its other applications—are often heavily involved
> simulations and calculations that are very resource demanding and
> could greatly benefit from LLVM's powerful optimization mechanisms.
> The LLVM project will, of course, benefit from having another
> front-end language and the resulting larger "market" available that
> can utilize LLVM. Additionally, the LLVM optimization team will have
> another case study to explore the effectiveness of its optimization
> routines. Especially the development of mixed-language optimization
> routines involving FORTAN and one or more other language may be
> explored and implemented.
>
> Deliverables for this project are:
> * FORTRAN front-end to LLVM
> * Documentation and tools for using the front-end
>
> DETAILED DESCRIPTION
> ----------------------------
>
> The reader should refer to the abstract for a description of the goals
> of this project and their justifications. This section is devoted to
> the applicant's experience, interests, qualifications, and plan for
> completing the project.
>
> * Personal Background
>
> I am a Junior, Environmental Engineering and Economics double major at
> Swarthmore College and do not come from a traditional Computer Science
> background. My story is the standard "taught himself to program at
> twelve, no time for stuffy computer science courses" narrative. My
> programming ideology is one of problem solving: I encounter a problem
> in my life and solve it using whatever tools or resources are needed
> to do so. To this end, I have dabbled in a wide range of fields from
> databases, to statistical analysis, to GUI applications, to web
> applications, and more. Examples of this work are an anti-censorship,
> in-browser web-browser (it's ridiculous, I know, but darn useful)
> [http://palary.com] and Longhand a calculator program for OS X
> [http://longhand.palary.com]. I have also worked for a number of
> clients developing GUI applications, data analysis applications, and
> web applications.
>
> I became interested in the area of language development as a result of
> a desire for better tools to deal with the environmental modeling and
> economical modeling issues that I came into contact with in my
> studies. It seemed to me like these areas could benefit greatly from
> domain specific languages that were tailored to their specific needs
> (such as built in units in the environmental modeling case). I am
> currently working toward developing such a language for my Senior
> Thesis here at Swarthmore.
>
> * Motivation
>
> To gain the background to carry out the complicated task of developing
> a domain specific modeling language, I have since wiggled my way
> around the pre-requisites and enrolled in an upper-level compiler
> course here at Swarthmore. Additionally, I have actively immersed
> myself in the field. In this immersion I came across the LLVM project
> and I believe that its IR would be an excellent target for the
> language I eventually create.  LLVM is, of course, a complex tool and
> I wish to gain much more familiarity with it.
>
> This is my primary motivation for working on a FORTRAN front-end:
> gaining experience and background. I am here to learn, and if my
> learning allows both the LLVM community and the FORTRAN community to
> receive an excellent tool, as it assuredly will, so much the better.
>
> * The Plan
>
> I will possess roughly three-months this summer to work on the
> front-end, and I am very confident that it will be completed on time
> (I am actually thinking that I could do much more in that period, but
> I learned long ago not to stick my head out on thing like this :).
>
> I am not as familiar with the technologies involved as I would like
> to, so my planning is necessarily imprecise. My rough plan proceeds as
> follows:
>
> =====
> - 2 weeks – Become familiar with the technologies: LLVM, FORTAN (I've
> programmed a lot of languages, but never that), and GCC's FORTAN
> implementation. Do not engage in any direct work on the projects but
> gain experience with the tools. Ascertain what previous work has been
> accomplished towards developing a FORTRAN front-end.
>
> - 4 weeks – Build the FORTRAN front-end.
>
> - 2 weeks – Smooth things out, unit tests, etc…
>
> - 1 week – Documentation, make sure that the front-end can be
> maintained by someone else.
>
> - 3 weeks – "Shit Happens"
> =====
>
> I plan on first attempting to implement the FORTRAN front-end by
> co-opting the GCC FORTRAN parser. If that fails, I will build a
> front-end using ANTLR [http://antlr.org] a parser generator with which
> I am familiar and for which a FORTRAN grammar is already available
> (targeting an obsolete version of ANTLR, but it should not be too
> difficult to update).
>
> * In Short
>
> I'm psyched :)
>
> I am confident that this is a very manageable project, I will complete
> it on time, and I will learn a great deal in the process of
> implementing it.
>