similar to: High memory use and LVI/Correlated Value Propagation

On 01/13/2016 04:28 PM, Daniel Berlin via llvm-dev wrote: > > > On Wed, Jan 13, 2016 at 4:23 PM, Joerg Sonnenberger via llvm-dev > <llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>> wrote: > > On Wed, Jan 13, 2016 at 03:38:24PM -0800, Philip Reames wrote: > > I don't think that arbitrary limiting the complexity of the > search

----- Original Message ----- > From: "Daniel Berlin via llvm-dev" <llvm-dev at lists.llvm.org> > To: "Joerg Sonnenberger" <joerg at britannica.bec.de>, "llvm-dev" > <llvm-dev at lists.llvm.org> > Sent: Thursday, January 14, 2016 10:38:10 AM > Subject: Re: [llvm-dev] High memory use and LVI/Correlated Value > Propagation > On

On Wed, Jan 13, 2016 at 03:38:24PM -0800, Philip Reames wrote: > I don't think that arbitrary limiting the complexity of the search is the > right approach. There are numerous ways the LVI infrastructure could be > made more memory efficient. Fixing the existing code to be memory efficient > is the right approach. Only once there's no more low hanging fruit should > we

On Wed, Jan 13, 2016 at 04:28:03PM -0800, Daniel Berlin wrote: > On Wed, Jan 13, 2016 at 4:23 PM, Joerg Sonnenberger via llvm-dev < > llvm-dev at lists.llvm.org> wrote: > > > On Wed, Jan 13, 2016 at 03:38:24PM -0800, Philip Reames wrote: > > > I don't think that arbitrary limiting the complexity of the search is the > > > right approach. There are

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:

On 2016-09-27 02:28, Philip Reames wrote: > On 09/20/2016 12:05 PM, Matti Niemenmaa via llvm-dev wrote: >> I posted some questions related to implementing inference of nsw/nuw >> flags based on known icmp results to Bug 30428 ( >> https://llvm.org/bugs/show_bug.cgi?id=30428 ) and it was recommended >> that I engage a wider audience by coming here. The minimal context is

Hi guys, I have an analysis that is able to answer questions like this: given an integer variable, what is the interval of values that this variable can assume during the program's execution? I want to integrate this analysis into LLVM and it seems LVI (Lazy Value Info) is the best place to do this kind of stuff. Can someone give some hints about what I have to do to integrate my analysis

Hi guys, I am trying to figure out how to use your Lazy Value Info pass, but I am having some questions. First, it seems that the implementation contains infra-structure to deal with range intervals, but the main interface only gives the client information about which values are constants. Is this true? Second, reading the code I see that the ranges are being computed, but I could not tell if

Hi, Is it intentional that LazyValueInfo.getPredicateAt doesn't solve for the value and only takes assumptions into account? getPredicateAt gets lattice value from cache using getValueAt call: LVILatticeVal LazyValueInfoCache::getValueAt(Value *V, Instruction *CxtI) { ... LVILatticeVal Result; mergeAssumeBlockValueConstantRange(V, Result, CxtI); ... return Result; } Other

Hi everyone, I posted some questions related to implementing inference of nsw/nuw flags based on known icmp results to Bug 30428 ( https://llvm.org/bugs/show_bug.cgi?id=30428 ) and it was recommended that I engage a wider audience by coming here. The minimal context is the following, please see the bug report for more detail: > 1. If (X s< Y), then both X + 1 and Y - 1 are nsw. > 2.

I am primarily interested in phi nodes and their induction variables, in ValueTracking file there is an analysis of them, but if the upper bound is inf, it is not working? 2017-08-07 11:41 GMT+02:00 Anastasiya Ruzhanskaya < anastasiya.ruzhanskaya at frtk.ru>: > So, it is not supported to determine by this instruction : %cmp = icmp slt > i32 %i.03, 99, > that %i.03 = phi i32 [ 0,

Thanks, maybe we could use ScalarEvolution in LazyValueInfo if it is available? On Mon, Jul 24, 2017 at 1:44 PM, John Regehr via llvm-dev < llvm-dev at lists.llvm.org> wrote: > Since they are different static analyses there's no reason to expect them > to agree, but they should both be conservative. In other words, if you like > you can compute the intersection of the two

On Mon, Aug 7, 2017 at 2:14 AM, Anastasiya Ruzhanskaya via llvm-dev <llvm-dev at lists.llvm.org> wrote: > I am trying to print it like this (maybe here is smth wrong?) > > > LazyValueInfo &LV = getAnalysis<LazyValueInfoWrapperPass>().getLVI(); > DominatorTree &DT = > getAnalysis<DominatorTreeWrapperPass>().getDomTree(); > LV.printLVI(F,

Hi, I am trying to call LowerSwitchPass directly in my custom pass in this way: FunctionPass *lower = createLowerSwitchPass(); lower->runOnFunction(*f); But it will crash when running lower->runOnFunction(*f) in llvm-9. I was using this method in llvm-8 and it worked fine. It seems the crash happens at the first line of the LowerSwitch::runOnFunction(Function &F) in the newer

There is no “switch” instruction in the target object code. It usually gets compiled into a switch table with instructions to load from it. Afaik Zhang > 在 2019年12月26日，17:49，n3v3rm03 via llvm-dev <llvm-dev at lists.llvm.org> 写道： > > Sorry I found an early thread discussing this question. I guess I shouldn't create lower switch pass like this. > However, I have another

On Sun, Feb 5, 2017 at 3:41 PM, Nuno Lopes <nunoplopes at sapo.pt> wrote: > Thanks for the answers! The plan makes sense to me. > > Regarding phis, what about diamonds, e.g.: > > > define i32 @f(i32 %x) { > br .., label %bb0, label %bb1 > bb0: > %cmp = icmp sge i32 %x, 0 ; x > 0 > br i1 %cmp, label %bb2, label %bb3 > bb1: > %x2 = add nsw

While building test-suite with the new PM, I ran into problems with AssertingVH being triggered which is obvious in retrospect: https://llvm.org/bugs/show_bug.cgi?id=28400 Both cases I ran into revolve around LVI which holds AssertingVH. Essentially, what happens is this: 1. LVI holds an AssertingVH pointing at a BasicBlock 2. Some other pass ends up deleting that BB (e.g. SimplifyCFG) 3. BOOM

On Mon, Jul 24, 2017 at 2:29 PM, John Regehr via llvm-dev < llvm-dev at lists.llvm.org> wrote: > On 7/24/17 3:16 PM, Hongbin Zheng via llvm-dev wrote: > >> Thanks, maybe we could use ScalarEvolution in LazyValueInfo if it is >> available? >> > > This should be fairly easy to try, if you want to propose a patch and run > some experiments. The question is

The current gvn equality propagation is not powerful enough to get this because it doesn't try to infer values in predicates based on other predicates, so it never realizes a>b -> a !=b in a useful way. It otherwise would get this On Thu, Jun 30, 2016, 7:41 PM Sean Silva <chisophugis at gmail.com> wrote: > On Thu, Jun 30, 2016 at 6:45 PM, Daniel Berlin via llvm-dev <

Looks like LVI actually does have cases for max and min; would it be better to allow ValueTracking to use range analysis instead? - CL > On Aug 1, 2016, at 8:44 PM, Philip Reames <listmail at philipreames.com> wrote: > >> On 07/29/2016 07:08 PM, Carlos Liam via llvm-dev wrote: >> Hi all, >> >> Say we have this IR: >> >> %1 = icmp slt i16 %x, 0