On the 0x3CE day of Apache Harmony Simon Chow wrote: > On 17 Jan 2008 13:31:05 +0300, Egor Pasko <[EMAIL PROTECTED]> wrote: > > > > On the 0x3CE day of Apache Harmony Simon Chow wrote: > > > On 17 Jan 2008 11:08:54 +0300, Egor Pasko <[EMAIL PROTECTED]> wrote: > > > > > > > > On the 0x3CD day of Apache Harmony Simon Chow wrote: > > > > > I am studying OPT in jitrino. For understanding the process of > > building > > > > CFG, > > > > > I have read some code of JavaByteCodeTranslator. > > > > > In the constructor of JavaByteCodeTranslator, there is an additional > > > > pass > > > > > named JavaLabelPrepass, > > > > > I would like to ask what is the exact purpose of this pass? > > > > > > > > the purpose is to mark basic blocks and inference stack variables and > > > > local variables with their types. > > > > > > > > This information goes to the input of JavaByteCodeTranslator, which in > > > > single pass goes through each bytecode instruction and converts it to > > > > operand-based representation from the stack-based in bytecode. > > > > > > > > The problem is a little tricky (with variable merging logic) and > > > > current design is poor. > > > > > > > > > Besides this, It is seems that the translator part will be refined, > > > > which I > > > > > saw in the wiki. Has it already been done in the current version? > > > > > Thanks! > > > > > > > > no, translator is not refined, low priority task. > > > > > > > > Why do you study the process of building CFG? If you want to do > > > > something with it, I would suggest to try some other place since all > > > > JIT people here will agree that debugging JavalabelPrepass is > > > > brain-damaging. > > > > > > > > > Thank! > > > I am doing a project for combining static compiler with dynamic > > compilation > > > environment (jitrino.OPT) > > > As first step, now I am planning to translate the Harmony IR to WHIRL. > > > > hm, do you have a kind of draft design document on how you want to do > > this? ..probably Harmony gurus can give some valuable input having > > read this doc. > > > There is no document for this yet, but I will write one in the next few days > after having a discussion with others in my group. > Our static compilation platform is Open64, some of my teammates are working > on it.
just to make sure.. is the primary goal to replace/enhance Jitrino.OPT on IPF machines? Oh, those itanics.. > I only have a little understanding of jitrino.OPT. > For achieving higher performance, which part or phases of jitrino.OPT could > be refined or replaced by Open64 optimization? > Could you give me some suggestion? I am afraid I am not familiar with Open64 at all, and there are concerns using a mix of Jitrino.OPT and Open64 since the latter is licensed under GPL. So, do not show me their code :) Jitrino.OPT/IPF is rather immature/experimental/untested/etc. So, if using Jitrino.OPT on IPF consider throwing away the code generator (but take care about generating the right calling convention and VM-related stuff like threading) As for the High-level optimizations, I do not know, where Open64 is better, maybe Xiaofeng knows? :) I may try to forsee something: Fortran & C compilers have more freedom for code motion and prefetch optimizations than a Java JIT compiler (which has a more dynamic nature), so, when ported to Java realities a C compiler is likely to behave not very cool. I would suggest you to enhance Jitrino IPF codegenerator in if-conversion and register allocation, that looks like more interesting and performance-beneficial. However, I am not sure if it suits you good as a subject of research. Did you try running DRLVM on IPF? Does it work? Does it even compile? > By the way, This idea is original from Xiaofeng :) > > Thank you every much! > > > But I can not find more information for the CFG structure in jitrino.OPT, > > > which leads me to read the code in translation part. :( > > > Any advice for this? > > > > there is no complete reference guide for HIR instructions yet. Once I > > gave advice on this: > > > > http://article.gmane.org/gmane.comp.java.harmony.devel/24474/ > > > > feel free to ask specific questions on CFG and instructions :) > > > > -- > > Egor Pasko > > > > > > > -- > From : [EMAIL PROTECTED] School of Fudan University -- Egor Pasko
