similar to: Enabling EarlyCSE w/ MemorySSA by default

+1 If possible, it definitely helps to fuzz it. On Sat, Jun 10, 2017 at 2:45 PM, Davide Italiano via llvm-dev < llvm-dev at lists.llvm.org> wrote: > On Sat, Jun 10, 2017 at 8:21 AM, Geoff Berry via llvm-dev > <llvm-dev at lists.llvm.org> wrote: > > Hi All, > > > > I'd like to switch the function simplification run of EarlyCSE to use > > MemorySSA by

Can you share you compile-time and memory footprint measurements at least for CTMark? For a new pass/feature it would be great to share this with the community before you commit. Or did I miss them? Thanks Gerolf > On Jun 27, 2017, at 3:26 PM, Geoff Berry via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > EarlyCSE w/ MemorySSA has been enabled by default as of r306477 >

For what it's worth, I just ran this on PowerPC and a double bootstrap with lit and lnt tests passes everything. On Sun, Jun 11, 2017 at 12:38 AM, Zhendong Su via llvm-dev < llvm-dev at lists.llvm.org> wrote: > Sure, we are happy to start some testing to see what we may help find. > > On Sat, Jun 10, 2017 at 3:36 PM, Daniel Berlin <dberlin at dberlin.org> > wrote:

When we erase a memory access instruction, existing passes using memory ssa like GVN, NewGVN, GVNHoist and EarlyCSE uses MemorySSAUpdater to do the update before the instruction is erased. However, if we call llvm::RecursivelyDeleteTriviallyDeadInstructions to find out dead instruction recursively and memory access instructions may be erased inside the recursive process, we need a way to update

Hi Daniel, Thanks for the info. I’ve started looking into converting EarlyCSE to use MemorySSA first since 1) I don’t think it needs any additional MemorySSA update API and 2) the particular case I’m looking at needs EarlyCSE to catch more load cases before LICM to be profitable. I have a prototype working, but have run into two issues: 1) readonly calls are treated as clobbers by

Sounds good to me. On 6/19/2017 2:27 PM, Davide Italiano via llvm-dev wrote: > On Mon, Jun 19, 2017 at 11:22 AM, Nemanja Ivanovic via llvm-dev > <llvm-dev at lists.llvm.org> wrote: >> For what it's worth, I just ran this on PowerPC and a double bootstrap with >> lit and lnt tests passes everything. >> > I fixed the only bug that has been reported (there were

1) Sounds good. This isn’t holding me up so I’ll just try to keep an eye out for these changes. 2) I’ve attached an example IR file and debug log of where the caching is going bad. It depends on my changes to EarlyCSE, but hopefully it is clear from the debug output what is going on. Let me know if there is a better way to get this repro case to you. Also, I’ll be on IRC for the

Hi George, After digging a little deeper, it appears that readonly calls showing up as MemoryDefs is only happening on an EarlyCSE test that is using the new pass manager (test/Transforms/EarlyCSE/basic.ll test5 if you’re curious), so I suspect it is an issue with the new pass manager setup code for either MemorySSA, my changes to EarlyCSE, the test run command line or something else not

Hi guys, I think I have run into another CachingMemorySSAWalker cache bug. It's a bit tricky to reproduce, so I'd like to start by trying to show you what is happening when running EarlyCSE with my local changes to use MemorySSA. I've attached a debug log that shows that the value returned by getClobberingMemoryAccess(Inst) after a call to removeMemoryAccess is wrong. The

Hi Florian, Following up on D86967, I missed that all the timings were using the legacy pass manager. Did you do any testing on the compile and run time impact for the new pass manager? Thank you, Alina On Tue, Aug 25, 2020 at 12:51 PM Florian Hahn <florian_hahn at apple.com> wrote: > Hi, > > Thanks for all the responses! > > My understanding is that there were no

I suspect something is pulling the RHS of the memorydef and caching it for calls it should not be used for. In particular, i suspect we are about to discover we can't cache the results from both versions of getClobberingMemoryAccess together, or that the cache is not always getting consistently written. On Mon, May 2, 2016 at 11:16 AM, George Burgess IV < george.burgess.iv at

I've put my changes to EarlyCSE that trigger this case up on phab here: http://reviews.llvm.org/D19821. These changes depend on http://reviews.llvm.org/D19664 so that will need to be applied first. With these changes applied, the original attached .ll file should trigger this bug when compiled with opt -early-cse -early-cse-use-memoryssa On 5/2/2016 2:34 PM, Daniel Berlin wrote: >

Hello all, It seems that it is insufficient to rely on MemorySSA to correctly reorder load/stores. For example, we have this following code: v = load q store 10, p => store 10, p v = load q // This is incorrect if p and q may alias In the MemorySSA representation however, there's no syntactic dependency between load/store, because MemorySSA before transformation would look like this:

Hi, we would like to propose a new Global Value Numbering pass in LLVM. The ideas/code are from Daniel Berlin (with a minor overhaul/splitting into submittable patches from me). The code has been around for a while (2012 or before), and we think it's getting ready to be committed upstream. ### Motivation To put things into context: my personal motivation for having a new GVN/PRE algorithm

Maybe. It may not fix it directly because you never use %1 or %2 again. I haven't looked to see how good the lookup is. On Fri, Jun 10, 2016, 3:45 PM Josh Klontz <josh.klontz at gmail.com> wrote: > Thanks Daniel, with that knowledge I think I can at least work around the > issue in my frontend. > > Ignoring GVN for a second though, and just looking at Early CSE, it seems

Hey folks, After a long amount of discussion both offline and on, I put a pass/intrinsic to add extended SSA up at http://reviews.llvm.org/D29316. Sean asked me to share it more broadly on llvm-dev, so here you go :) For those not familiar with extended-SSA, it's described in the paper "ABCD: Eliminating Array Bounds Checks on Demand". There is a very large amount of explanation

I have tried running both gvn and newgvn but it did not helped in hoisting the alias checks: Please check, maybe I have missed something. <TestCase> void foo (char *A, char *B, char *C, int len) { int i = 0; for (i=0 ; i< len; i++) A[i] = B[i] + C[i]; } <Command> $ opt –O3 –gvn test.ll –o test.opt.ll $ opt –O3 –newgvn test.ll –o test.opt.ll “test.ll” is attached, it

Hi All, I'm looking into converting LICM to use MemorySSA instead of AliasSets to determine when it is safe to hoist/sink/promote loads and stores to get around the issue of alias set collapse (see discussion [1]). I have a prototype implementation, but have run into two issues that I could use input from the designers of MemorySSA to resolve: 1) Is MemorySSA intended to be

On Wed, Nov 16, 2016 at 2:03 AM, David Chisnall via llvm-dev < llvm-dev at lists.llvm.org> wrote: > This is really great to see, as I’ve spent far too much of my life over > the past two years fighting with undocumented assumptions made by GVN. A > couple of quick questions about the new GVN, based on problems I’ve had > with the old one: > > Does it assume that it’s

Yeah, that change is completely unrelated, that is about correctness, this is about optimization. I'm working on a proposal to just fix assume at some point to deal with the former issue. The problem with this testcase is that all the ways assume is propagate expect the variable in the assume to later be used. <This is the main way assume constants are propagated> bool