similar to: Where did Alive go?

Sorry, we really screwed up the server migration. Alive is now working again and should be fixed for good :) Permalinks are still missing; we are working on recovering those. Apologies again for all the trouble. Nuno -----Original Message----- From: Sanjay Patel Sent: Monday, October 2, 2017 5:10 PM Subject: Re: [llvm-dev] Where did Alive go? I still can't use the web app - spins for

Craig I know it's a pain compared to the web interface but Alive is pretty easy to install and run from a shell. John On 9/22/17 11:41 AM, Craig Topper via llvm-dev wrote: > And now rise4fun.com <http://rise4fun.com> doesn't work at all? > > ~Craig > > On Wed, Sep 20, 2017 at 9:53 AM, Nuno Lopes <nunoplopes at sapo.pt > <mailto:nunoplopes at

And now rise4fun.com doesn't work at all? ~Craig On Wed, Sep 20, 2017 at 9:53 AM, Nuno Lopes <nunoplopes at sapo.pt> wrote: > Alive is now working again. There was a migration to a new server. > Permalinks are still being copied from backup; they will work again > shortly as well. (I would probably not create new ones since they may get > replaced while the copy is in

Alive is now working again. There was a migration to a new server. Permalinks are still being copied from backup; they will work again shortly as well. (I would probably not create new ones since they may get replaced while the copy is in flux). Nuno Citando Nuno Lopes via llvm-dev <llvm-dev at lists.llvm.org>: > I'm investigating; thanks for the heads up. Sorry for the

I'm investigating; thanks for the heads up. Sorry for the trouble. Nuno -----Original Message----- From: Craig Topper via llvm-dev Sent: Tuesday, September 19, 2017 11:52 PM Subject: [llvm-dev] Where did Alive go? This no longer works http://rise4fun.com/Alive ~Craig

Hi Sanjay, You used Alive correctly, of course :) At this moment we cannot give you the best precondition. It’s on the todo list, but it’s not even started yet. It’s a much harder problem to solve. We do have a mode to compute the best set of nsw/nuw/exact attributes in the transformed expression, but it’s not enabled on the web interface yet (InstCombine was missing quite a few cases last

Not sure how off-topic this is, but should we consider/have we considered porting our InstCombines to Alive? The PLDI '15 paper even demos C++ extraction from Alive theorems. I think it'd be a small step from that to extracting tightly optimized VM code, not unlike what Tablegen emits. Everything would be so clean and readable and organized. And edge cases can still be handled manually,

Hi, Just a short email to announce that Alive is now available online: http://rise4fun.com/Alive The site includes a few examples (both correct and buggy). You can also create a "permalink" to send the proof to someone else. The execution time is limited to 30 seconds for now. You may want to constrain the operand's types if the tool times out, for example. The service is

+1 to alive2.llvm.org On Thu, Jun 18, 2020 at 8:11 AM John Regehr via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > > If we can get Alive1 up there too, that would be even better. I still > > use that to try to prove things where it's not obvious how to express > > the relationships in pure LLVM IR: > > https://rise4fun.com/Alive/NDu > > I don't

No concerns from me. I use Alive2 all the time, and it would be fantastic to have it available online reliably. If we can get Alive1 up there too, that would be even better. I still use that to try to prove things where it's not obvious how to express the relationships in pure LLVM IR: https://rise4fun.com/Alive/NDu On Wed, Jun 17, 2020 at 4:05 PM Chris Lattner via llvm-dev < llvm-dev at

Some InstCombine transforms for select-of-select were added here: https://reviews.llvm.org/rL228409 But Alive says this is more poisonous: Name: selsel %s1 = select i1 %cond1, i8 C1, i8 C2 %s2 = select i1 %cond2, i8 %s1, i8 C2 => %andcond = and i1 %cond1, %cond2 %s2 = select i1 %andcond, i8 C1, i8 C2 http://rise4fun.com/Alive/JT6 Are those transforms legal? -------------- next part

Hi folks, I've been running a Compiler Explorer instance with Alive2 on a machine in my office, but availability has been poor due to random factors and of course recently it hasn't been easy or convenient to go in and fix things when the machine gets wedged. Nuno and I would like to ask the LLVM community if it's OK to point alive.llvm.org at a cloud machine that I've setup

Hi, Let me try to give a bit more context on why select is so tricky. First thing to consider is which transformations we would like to support: 1) Control-flow -> select (SimplifyCFG) if (c) a = x else a = y => %a = select %c, %x, %y 2) select -> control-flow; reverse of 1) Not sure if this is done at IR level, or only later at SDAG. 3) select ->

Regarding the patches, there are two concerns AFAICT: 1. It’s a new instruction and as usual when introducing a new instruction it will require work for some time until most optimizations know about it, and to get rid of any potential perf regression. No big deal; we just need to do the work (and we have already done some of it). 2. The patch was written by a student, which may not have time to

I'm looking at the output of memcmp() expansion (D34904), and I noticed that there are many ways to produce the common positive/zero/negative comparison result in IR. For the following 6 functionally equivalent C source functions, we produce 6 different versions of IR which leads to 6 different asm outputs for x86. Which of these should we choose as canonical IR form? 1. Two selects int

Daniel, Thanks for taking the time to respond. Regarding GVN and newGVN, I recently finished a search through the llvm-dev archives for “nsw” in the subject line, and GVN was discussed in some of those threads [1]. In particular it was claimed that there was a right choice for GVN to make given two ADD instructions, one with the “nsw” attribute and one without, the one without ‘nsw’

Hello. This question has come up in https://reviews.llvm.org/D70043 There, i'm teaching ConstantRange how no-wrap flags affect the range of `mul` instruction, with end goal of exploiting this in LVI/CVP. There are certain combinations of ranges and no-wrap flags that result in always-overflowing `mul`. For example, `mul nuw nsw i4 [2,0), [4,0)` always overflows:

Ok, makes sense. My suggestion is that we patch the IR Verifier to ensure that the mask is indeed a vector of constants and/or undefs. Right now it only runs the standard checks for instructions. We will also run Alive2 on the test suite to make sure undef is never replaced in practice. Thanks, Nuno -----Original Message----- From: Eli Friedman <efriedma at quicinc.com> Sent: 27 de

Hi Sanjay, thanks for enlighten me on terms of tests. I assume I have to run the test-suite benchmarks to check for regressions? Is there a guide to get the metrics from the benchmarks? Cheers, Michael BTW the beginner tag for bugs was really a good idea to get started with contributing to llvm. On Tue, Sep 19, 2017 at 3:58 PM +0200, "Sanjay Patel" <spatel at

There are at least 3 active proposals to add reassociative optimizations in IR: [1] D41574 <https://reviews.llvm.org/D41574>- a new pass for reassociation/factoring [2] D46336 <https://reviews.llvm.org/D46336> - enhance -instcombine to do more reassociation/factoring [3] D45842 <https://reviews.llvm.org/D45842> - add to the existing -reassociate pass to enable factoring