search for: gvnpre

It seems the GVNPRE pass has been removed from the main trunk, though it is present in the 2.6 release. From the llvm-commits archive, I found that it was removed  with this checkin: http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20090928/088214.html "remove the GVNPRE pass. It has been subsumed by...

Hello, I am doing a course project of "Adding the strength reduction in existing GVNPRE implementation". But the problem which I am facing is that for many sample programs I tried, the "gvnpre" pass of opt doesn't perform PRE and it leaves the code as it is. This is my sample program and it should do PRE on it but opt is not performing it. Kindly help me out in thi...

...d%d",&a,&b); if (argc > 1) { k=a+b; } else { k=5; } l=a+b; printf("%d,%d",k,l); return 0; } Now i run the following on it: llvm-gcc -O1 -emit-llvm -c -o 1.bc 1.c llvm-dis 1.bc -o 1.ll opt -gvnpre 1.bc -o 1p.bc // I believe this line writes the code to 1p.bc after applying gvnpre to 1.bc llvm-dis 1p.bc -o 1p.ll Now 1.ll is as : -----------------------------------------------------------------------------------------------------------------------------------------------------...

Hi All, The PRE or GVNPRE is not effective for the below use case. int sum; int phi =30; void f (int i, int *a) { if ((a[i] << (1)) > -15) sum =(phi+ 0x7fffffffL )/ a[i]; if ((a[i] << (2)) > -15) sum =(phi + 0x7fffffffL) /a[i]; } respective asm (clang on trunk ) #clang -O3 -S test.c BB#0:...

Hi LLVMers, I am a PHD student in CS dept in UIUC, I am doing a project for Vikram's course, it is about PRE. I would like to know why you didn't choose SSAPRE in LLVM, since it seems to be more suitable for LLVM (it can operate directly on SSA form and avoid the conversion between SSA and bit-vector). Can anyone tell me the reason? Xuehai

...r insights/prototype? I think I can spend more time on implementation. Thanks, Taewook ________________________________ From: Daniel Berlin <dberlin at dberlin.org> Sent: Tuesday, April 4, 2017 9:41:30 PM To: Taewook Oh Cc: llvm-dev at lists.llvm.org Subject: Re: [llvm-dev] [NewGVN] Plan for GVNPRE? Of course As a heads up, it's likely to be a while (ie 3-6 months or maybe longer) if you leave it to me. I try to stay out of the critical path, because my real day job is managing folks who work on llvm (and other things), not working on llvm, and that has a lot of interrupts :) This is wh...

Hi Daniel, Thank you for your detailed reply, and thank you for working on GVNPRE. I’d more than happy to test/evaluate it with our benchmark once it is ready. Please let me know if you need any help. Thanks, Taewook From: Daniel Berlin <dberlin at dberlin.org> Date: Tuesday, April 4, 2017 at 6:13 PM To: Taewook Oh <twoh at fb.com> Cc: "llvm-dev at lists.llvm....

...; * New Transformations and Analyses > - Implement GVN-PRE > - Value range propagation pass > > What do you think, would any of these two make a good SoC project? To me, GVN-PRE and a MIPS backend would be the most useful ones. Do you have MIPS hardware to test on? If not, a GVNPRE pass might be better, though you could do the port with a good simulator. Daniel Berlin knows much about GVNPRE, so he could probably comment more on it. -Chris -- http://nondot.org/sabre/ http://llvm.org/

> To me, GVN-PRE and a MIPS backend would be the most useful ones. Do you > have MIPS hardware to test on? If not, a GVNPRE pass might be better, > though you could do the port with a good simulator. Daniel Berlin knows > much about GVNPRE, so he could probably comment more on it. I implemented GVN-PRE for GCC. You could probably do an implementation for LLVM in three months, assuming you are somewhat familiar...

Hi, I'm planning to apply for SoC and I would like some hints on which projects the community are most interested in. The two projects that I right now think looks most interesting is: * Writing an backend for MIPS and * New Transformations and Analyses - Implement GVN-PRE - Value range propagation pass What do you think, would any of these two make a good SoC project?

Hello, In some of our internal benchmarks, I observe that LLVM performs worse than GCC because LLVM fails to perform PRE when GCC can. I hope this problem goes away when NewGVN equipped with PRE, and wonder if anyone has an idea about the status of PRE on top of NewGVN. Thanks! Best, Taewook -------------- next part -------------- An HTML attachment was scrubbed... URL:

...look at LLVM's svn history, there are old PRE implementations that have been deleted: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/PRE.cpp?view=log&pathrev=25348 (e-path PRE, like the paper above) http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/GVNPRE.cpp?revision=80766&view=markup&pathrev=83192 (GVNPRE) Making a worthwhile PRE that is not slow tends to be quite an engineering task. > >> >> >> If you want to implement the original SSAPRE, i suggest looking at >> http://jcse.kiise.org/posting/2-3/jcse_2-3_31....

I have written a simple pass. I have been successful to execute it. I want LLVM to execute it. I don't know how to include a pass in llvm actual pass list, such it automatically invokes it just like GVNPre pass or some other pass. They have already been limked in llvm actual pass list. -- regards, soumya prasad ukil -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20100821/440cb06d/attachment.html>

...> <mailto:ukil.soumya at gmail.com>> wrote: > > I have written a simple pass. I have been successful to execute it. > I want LLVM to execute it. I don't know how to include a pass in > llvm actual pass list, such it automatically invokes it just like > GVNPre pass or some other pass. They have already been limked in > llvm actual pass list. > > -- > regards, > soumya prasad ukil > > > > > -- > regards, > soumya prasad ukil > > > > _______________________________________________ > LLVM De...

Hello, I am doing a course project of "Adding the strength reduction in existing GVNPRE implementation". I know GVNPRE is not maintained and has been removed from trunk. But still can I get a single sample program for which it works correctly? Because for all the programs which I have tried it does not perform PRE.One such program is attached with this mail. It is important for...

...21 August 2010 17:32, Soumya_Prasad_Ukil <ukil.soumya at gmail.com> wrote: > I have written a simple pass. I have been successful to execute it. I want > LLVM to execute it. I don't know how to include a pass in llvm actual pass > list, such it automatically invokes it just like GVNPre pass or some other > pass. They have already been limked in llvm actual pass list. > > -- > regards, > soumya prasad ukil > -- regards, soumya prasad ukil -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-d...

On Sun, Nov 3, 2013 at 1:02 AM, Daniel Berlin <dberlin at dberlin.org> wrote: > As for a "better" way to implement PRE, it depends on what algorithm > you want to use. If you just want to write a PRE pass, that's easy > enough without dominance frontiers. > I simply want to write a PRE pass to get a better understanding of the transformation. Any tips on where to

...ng > academic project .for,that i have a sample c++ program and its .ll > file.anyone have SSAPRE implementation in c++. if anyone have, please give > me that implementation immediately. In the old version of LLVM, the GVN pass also does PRE. But by default, PRE is not on. We need to set -gvnpre to make it work. ''opt --help'' will list all flags for optimizations. I am not sure if the latest LLVM still has the flag. > > joseykollam at gmail.com > > josey @ 9895685353 > elw technologies > cochin > > > ____________________________________________...

i wish to develop llvm SSAPRE compiler optimization for my engineering academic project .for,that i have a sample c++ program and its .ll file.anyone have SSAPRE implementation in c++. if anyone have, please give me that implementation immediately. joseykollam at gmail.com josey @ 9895685353 elw technologies cochin -------------- next part -------------- An HTML attachment was scrubbed... URL:

...ukil.soumya at gmail.com>> wrote: >> >> I have written a simple pass. I have been successful to execute it. >> I want LLVM to execute it. I don't know how to include a pass in >> llvm actual pass list, such it automatically invokes it just like >> GVNPre pass or some other pass. They have already been limked in >> llvm actual pass list. >> >> -- >> regards, >> soumya prasad ukil >> >> >> >> >> -- >> regards, >> soumya prasad ukil >> >> >> >>...