Getting the front end for Fortran finished is definitely something I would be interested in working on. I will draft up a little proposal and send it out to this list. -Scott On 3/19/07, Kenneth Hoste <kenneth.hoste at ugent.be> wrote:> Hi Scott, > > On 18 Mar 2007, at 04:22, Scott Fortmann-Roe wrote: > > > Hi, > > > > I noticed that LLVM had signed up as a mentoring organization for > > Google's summer of code. LLVM looks like an exciting project that > > overlaps some of my interests. > > > > I would be interested in developing an additional front end for a > > language it does not currently support (I'm open to what language). I > > do not know much about what this entails in regards to what LLVM > > requires from its front ends. But I have experience with the ANTLR > > parser generator that looks like it could be used to generate such a > > front end. > > > > Recently, there has been work done on a Fortran frontend. > Unfortunately, it was abandonded because of the switch the LLVM team > is currently making to a new bytecode format and, afaik, a new GCC > version in the near future. The rub is that the gfortran part of GCC > 4.0 isn't really mature, but the ones in 4.1 and the upcoming 4.2 are. > > I think getting a Fortran frontend working will highly benefit the > relevance of LLVM for researchers. Quite a few of the SPEC CPU2000 > and CPU2006 benchmarks are fully or partially written in Fortran, and > the SPEC benchmarks remain by far the most important benchmarks used > in computer architecture and compiler-related research. Allowing all > of the SPEC CPU200x benchmarks to compile using LLVM will vastly > increase it's use imho. > > greetings, > > Kenneth > > > Are you folks interested in this? > > > > If so, please let me know ASAP and I'll put together an application. > > > > -Scott > > _______________________________________________ > > LLVM Developers mailing list > > LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu > > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev > > -- > > Statistics are like a bikini. What they reveal is suggestive, but > what they conceal is vital (Aaron Levenstein) > > Kenneth Hoste > ELIS - Ghent University > kenneth.hoste at elis.ugent.be > http://www.elis.ugent.be/~kehoste > _______________________________________________ > LLVM Developers mailing list > LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev >-- Scott Fortmann-Roe 500 College Ave Swarthmore, Pa 19081 (510) 866-5296
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. On 3/19/07, Scott Fortmann-Roe <scottfr at gmail.com> wrote:> Getting the front end for Fortran finished is definitely something I > would be interested in working on. I will draft up a little proposal > and send it out to this list. > > -Scott > > On 3/19/07, Kenneth Hoste <kenneth.hoste at ugent.be> wrote: > > Hi Scott, > > > > On 18 Mar 2007, at 04:22, Scott Fortmann-Roe wrote: > > > > > Hi, > > > > > > I noticed that LLVM had signed up as a mentoring organization for > > > Google's summer of code. LLVM looks like an exciting project that > > > overlaps some of my interests. > > > > > > I would be interested in developing an additional front end for a > > > language it does not currently support (I'm open to what language). I > > > do not know much about what this entails in regards to what LLVM > > > requires from its front ends. But I have experience with the ANTLR > > > parser generator that looks like it could be used to generate such a > > > front end. > > > > > > > Recently, there has been work done on a Fortran frontend. > > Unfortunately, it was abandonded because of the switch the LLVM team > > is currently making to a new bytecode format and, afaik, a new GCC > > version in the near future. The rub is that the gfortran part of GCC > > 4.0 isn't really mature, but the ones in 4.1 and the upcoming 4.2 are. > > > > I think getting a Fortran frontend working will highly benefit the > > relevance of LLVM for researchers. Quite a few of the SPEC CPU2000 > > and CPU2006 benchmarks are fully or partially written in Fortran, and > > the SPEC benchmarks remain by far the most important benchmarks used > > in computer architecture and compiler-related research. Allowing all > > of the SPEC CPU200x benchmarks to compile using LLVM will vastly > > increase it's use imho. > > > > greetings, > > > > Kenneth > > > > > Are you folks interested in this? > > > > > > If so, please let me know ASAP and I'll put together an application. > > > > > > -Scott > > > _______________________________________________ > > > LLVM Developers mailing list > > > LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu > > > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev > > > > -- > > > > Statistics are like a bikini. What they reveal is suggestive, but > > what they conceal is vital (Aaron Levenstein) > > > > Kenneth Hoste > > ELIS - Ghent University > > kenneth.hoste at elis.ugent.be > > http://www.elis.ugent.be/~kehoste > > _______________________________________________ > > LLVM Developers mailing list > > LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu > > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev > > > > > -- > Scott Fortmann-Roe > 500 College Ave > Swarthmore, Pa 19081 > (510) 866-5296 >-- Scott Fortmann-Roe 500 College Ave Swarthmore, Pa 19081 (510) 866-5296
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. >
On Mar 19, 2007, at 5:53 PM, Scott Fortmann-Roe wrote: Hi Scott! Some comments inlined:> 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 >s/parsers/parses/> 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. >If you want, you could put a URL to LLVM's homepage in here somewhere.> 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. >Quite true! I've worked at some of these places. :-)> 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 >Could you also work on a suites of tests? It doesn't have to be compete or full-featured, but it's good to have tests hanging around so that you make sure you get things done correctly.> 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.I don't know how much Google wants in this section. One question I come away with is, "How does Fortran relate to your language?"> * 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. >I would suggest writing documentation along the way. Even if they are just notes to yourself. It will help this week go by faster (developers *hate* writing docs).> - 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). >One thing you don't mention is which version of Fortran you want to do: Fortran 77, 90, 95, ??. Each has their own challenges. If you're going to do a subset of one of the languages, then define how much of it you want to do, and then provide a roadmap for future work. I think it would be a good idea to scour the web looking for examples of Fortran programs out there. Build your front-end using these as testcases. Start with the simplest one, get it going, then get more complex. It will then be easy to make these small programs into testcases to include in the LLVM tester.> * 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. >Awesome! Good luck on it!! :-) A Fortran FE will be a much welcome addition. -bw
On 20 Mar 2007, at 01:53, Scott Fortmann-Roe 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?Some (quite a few actually, some more important than others) remarks: "that parsers the language and converts it" => "that PARSES the language and converts it" "The next component of LLVM" => "The second component of LLVM" "To claim FORTRAN is mature ... is involved." => mention SPEC CPU2000 and CPU2006 here as important examples of widely-used Fortran benchmarks for both the research community and industry "My story is the standard "taught himself to program at twelve, no time for stuffy computer science courses" narrative." => as Scott McMurray pointed out, don't use words like "spuffy", makes you sound like a script kiddie... Something like "My programming experience is self-taught, without major computer science courses." "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]." => references are good, but I don't think there's a worse way of selling them... Better: "Examples of this work are anti-censorship, an in-browser web-browser (which may sound superfluous, but is quite usefull; see http://palary.com), and a calculator program for OS X (Longhand, see http://longhand.palary.com)". "I have since wiggled my way around the pre-requisites and enrolled in an upper-level compiler course here at Swarthmore" => don't use wiggled (but since I'm not native English, I can't anything suitable at this time) "LLVM is, of course, a complex tool and I wish to gain much more familiarity with it." => drop the "of course" part, makes LLVM sound too bloody complex (it is complex, but also well structured) "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." => "My primary motivation for working an a FORTRAN front-end for LLVM is gaining experience and background in software development. I want to learn from this experience, and would like to contribute to both the LLVM and FORTRAN community doing so." "I will possess roughly three-months this summer to work on the front- end," => "I will be able to spend roughly three-months this summer to work on the front-end" "LLVM, FORTAN (I've programmed a lot of languages, but never that), and GCC's" => drop the part between brackets, makes the project sound less likely to succeed "- 1 week – Documentation, make sure that the front-end can be maintained by someone else." => I think it is consired better if you develop your documentation along with the implementation. Experience has taught me if you plan to comment your code afterwards, you won't. You could also state that the Documentation part will consist of hacking up examples or similar, but don't make it sound that you'll document your code afterwards, because you won't. "- 3 weeks – "Shit Happens" => Don't use shit :-) And maybe put this in a phrase: "The three remaining weeks will be used to solve problems related to the project which are not in the current plan" "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." => "I am thrilled to start working on this project, and feel that I will be able to complete it on time succesfully. While working on this project, I hope to learn a great deal." Please don't hesitate to show us your updated proposal again before sending it. greetings, Kenneth> > 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. > > > > On 3/19/07, Scott Fortmann-Roe <scottfr at gmail.com> wrote: >> Getting the front end for Fortran finished is definitely something I >> would be interested in working on. I will draft up a little proposal >> and send it out to this list. >> >> -Scott >> >> On 3/19/07, Kenneth Hoste <kenneth.hoste at ugent.be> wrote: >> > Hi Scott, >> > >> > On 18 Mar 2007, at 04:22, Scott Fortmann-Roe wrote: >> > >> > > Hi, >> > > >> > > I noticed that LLVM had signed up as a mentoring organization for >> > > Google's summer of code. LLVM looks like an exciting project that >> > > overlaps some of my interests. >> > > >> > > I would be interested in developing an additional front end for a >> > > language it does not currently support (I'm open to what >> language). I >> > > do not know much about what this entails in regards to what LLVM >> > > requires from its front ends. But I have experience with the >> ANTLR >> > > parser generator that looks like it could be used to generate >> such a >> > > front end. >> > > >> > >> > Recently, there has been work done on a Fortran frontend. >> > Unfortunately, it was abandonded because of the switch the LLVM >> team >> > is currently making to a new bytecode format and, afaik, a new GCC >> > version in the near future. The rub is that the gfortran part of >> GCC >> > 4.0 isn't really mature, but the ones in 4.1 and the upcoming >> 4.2 are. >> > >> > I think getting a Fortran frontend working will highly benefit the >> > relevance of LLVM for researchers. Quite a few of the SPEC CPU2000 >> > and CPU2006 benchmarks are fully or partially written in >> Fortran, and >> > the SPEC benchmarks remain by far the most important benchmarks >> used >> > in computer architecture and compiler-related research. Allowing >> all >> > of the SPEC CPU200x benchmarks to compile using LLVM will vastly >> > increase it's use imho. >> > >> > greetings, >> > >> > Kenneth >> > >> > > Are you folks interested in this? >> > > >> > > If so, please let me know ASAP and I'll put together an >> application. >> > > >> > > -Scott >> > > _______________________________________________ >> > > LLVM Developers mailing list >> > > LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu >> > > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev >> > >> > -- >> > >> > Statistics are like a bikini. What they reveal is suggestive, but >> > what they conceal is vital (Aaron Levenstein) >> > >> > Kenneth Hoste >> > ELIS - Ghent University >> > kenneth.hoste at elis.ugent.be >> > http://www.elis.ugent.be/~kehoste >> > _______________________________________________ >> > LLVM Developers mailing list >> > LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu >> > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev >> > >> >> >> -- >> Scott Fortmann-Roe >> 500 College Ave >> Swarthmore, Pa 19081 >> (510) 866-5296 >> > > > -- > Scott Fortmann-Roe > 500 College Ave > Swarthmore, Pa 19081 > (510) 866-5296-- Statistics are like a bikini. What they reveal is suggestive, but what they conceal is vital (Aaron Levenstein) Kenneth Hoste ELIS - Ghent University kenneth.hoste at elis.ugent.be http://www.elis.ugent.be/~kehoste
Hi Scott, I'm currently porting the Ada gcc front-end to LLVM. This is similar to what you want to do, so here are some comments from the trenches...> I plan on first attempting to implement the FORTRAN front-end by > co-opting the GCC FORTRAN parser.Good plan. However the Fortran front-end that comes with gcc 4.0 is known to be weak (llvm-gcc is based on gcc 4.0). That's because gcc 4.0 is based internally on a new infrastructure compared to gcc 3.0, and it took the front-ends a version or two to catch up and sort out the bugs. That was the case for Ada too, which is why the first thing I did was to backport the Ada front-end from gcc 4.3 to llvm-gcc. I advise you to backport the gcc 4.2 fortran front-end to llvm-gcc. For Ada this was quite easy to do. Last time I tried to build the fortran front-end in llvm-gcc it got quite a long way before it died. This is a good sign. I've found LLVM to be solid for code that can be produced by C, and easily fixed for the rest. There are four classes of problems: (1) build failures because some tree code is not handled. CIEL_DIV_EXPR is an example that is used by Fortran but isn't implemented yet, but these are usually easy enough to implement (I need to implement this one for Ada, so we'll see who gets there first!). (2) build failures because you're outside the world of C. I suspect Fortran will be less problematic than Ada, but even in the Ada case the LLVM design has proved sound, and each problem has individually been simple to fix. The tricky ones I had were (a) resolution of forward declarations; (b) handling of exotic packed bit fields. (3) build failures due to bugs in gcc 4.0. It can be tricky to tell if problems are due to a bug in the front-end or a gcc 4.0 bug. I had an example with the front-end producing non-constant constructors for global variables. It was actually the fault of one of the gcc 4.0 helper routines, and nothing to do with the front-end at all. These tend to be fairly easy to fix, because they've usually been fixed in more recent versions of gcc! So you have to muck around in gcc 4.2 to find out how come it works there, then backport the fix. (4) wrong code. I haven't seen many of these. Having a good testsuite helps to flush these out. I'm currently working my way through the Ada testsuite, which is quite comprehensive. Hopefully the fortran one is too.> 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).Bad plan. I doubt you can build a serious fortran compiler in this way in the time-frame you are considering. Good luck! Duncan.