similar to: LSR breaks debug info

What would it look like without this extension? If we modeled it as if all the register values were already on the stack (an extension of the current way where the singular value is modeled as being already on the stack, if I understand it correctly?)? If it's decided that the best approach is to introduce something like DW_OP_LLVM_register - might be worth migrating to that first (basically

>As the person who has advocated for DW_OP_LLVM_arg(N) before, my main motivation was to resolve the ambiguity of constant DIExpressions: As a worst-case example: > >dbg.value(%undef, !DILocalVariable(x), DIExpression(DW_OP_constu, 42)) > >Is this undefined, or constant 42? > >But if we make dbg.value fully variadic with all parameters pushed to the stack ahead of time, we can

Currently, the debug intrinsic functions each have 3 arguments: an SSA value representing either the address or Value of a local variable, a DILocalVariable, and a complex expression. If the SSA value is an Instruction, and that Instruction is at some point deleted, we attempt to salvage the SSA value by recreating the instruction within the complex expression. If the instruction cannot be

Hi, I find that LSR is not helping enough on avoiding unfoldable offsets for SystemZ. When the loop has three stores with unfoldable offsets, LSR rewrites the IV in a good way. However, if adding another store with a foldable offset that fits already, LSR fails to rewrite the three stores. And if I happen to add a too big *positive* offset (the first three were negative) instead of a

>> Has anyone any idea on how to best handle this? Can LSR "split" an IV >> to use an extra register? Or would this need to be done in a target >> specific pass? > > When you say "an extra address register" would this imply LSR adding > an additional PHI? > > -Hal > Yes, that would have worked well at least in this type of loop. Can LSR

On Wed, Sep 19, 2018 at 5:18 PM Adrian Prantl <aprantl at apple.com> wrote: > > > > > On Sep 19, 2018, at 4:08 AM, Alexander Potapenko <glider at google.com> wrote: > > > > On Tue, Sep 18, 2018 at 1:56 AM Adrian Prantl <aprantl at apple.com> wrote: > >> > >> > >> > >>> On Sep 17, 2018, at 6:59 AM, Alexander

Hi, I would like some help regarding the LSR pass. It seems that it likes to duplicate address calculations as in the case above, which is highly undesirable on my target. I wonder if there is any way to tell LSR to not duplicate the code in cases like this? Or could I perhaps run CSE after LSR again? What is the logic behind this transformation? It seems that a LSR pass should not insert a

----- Original Message ----- > From: "Yin Ma" <yinma at codeaurora.org> > To: "Andrew Trick" <atrick at apple.com> > Cc: llvmdev at cs.uiuc.edu > Sent: Thursday, March 14, 2013 4:21:50 PM > Subject: Re: [LLVMdev] Suggestion About Adding Target Dependent Decision in LSR Please > > > > > > Hi Andy, > > > > Actually,

I just filed bug 7872 about non-scalability of the LSR analysis algorithms. It may be related to bug 6727. The fundamental problem appears to be re-running SCEV analyses such as properlyDominates and SCEVComplexityCompare over and over again on large SCEV expressions. Memoizing results for SCEVComplexityCompare appears to help significantly but that is much harder to do with things like

Hi, The target supports indexing by register or immediate. Multiplications are not supported by any load / store instructions. Would it be possible to make LSR aware of this? Thanks, Jonas Paulsson -----Original Message----- From: Hal Finkel [mailto:hfinkel at anl.gov] Sent: Saturday, December 01, 2012 5:59 AM To: Jonas Paulsson Cc: llvmdev at cs.uiuc.edu Subject: Re: [LLVMdev] LSR pass

Thanks! It looks like SelectionDAG::salvageDebugInfo handles only addition with constant. Sejong From: aprantl at apple.com <aprantl at apple.com> Sent: Monday, April 30, 2018 1:53 PM To: Se Jong Oh <sejooh at microsoft.com> Cc: jdevlieghere at apple.com; Vedant Kumar <vsk at apple.com>; llvm-dev at lists.llvm.org; pidgeot18 at gmail.com Subject: Re: [llvm-dev] [SelectionDAG]

----- Original Message ----- > From: "Jonas Paulsson" <jonas.paulsson at ericsson.com> > To: llvmdev at cs.uiuc.edu > Sent: Monday, November 26, 2012 1:40:24 PM > Subject: [LLVMdev] LSR pass > > > > > > Hi, > > > > I would like some help regarding the LSR pass. It seems that it likes > to duplicate address calculations as in the

I also noticed LSR spending a lot of time in GenerateAllReuseFormulae, just to have some cases pruned in NarrowSearchSpaceUsingHeuristics. I'm not familiar enough with the code to comment on how this affects the quality of LSR results, but a hack is to "EstimateSearchSpaceComplexity" inside the loops of GenerateAllReuseFormulae and cut out early. - Jan On Wed, Aug 11, 2010 at 2:48

On Mar 13, 2013, at 4:37 PM, Yin Ma <yinma at codeaurora.org> wrote: > Hi All, > > In the target I am working, we comes cross a situation that the loop strength reduction > could deliver a better result but currently not, because > 1. the algorithm narrows search space by winner registers without considering > the target preferred format.

On Wed, Sep 2, 2015 at 5:36 AM, James Molloy <james at jamesmolloy.co.uk> wrote: > Hi, > > Coremark really isn't a good enough test - have you run the LLVM test suite > with this patch, and what were the performance differences? For the test suite single source benches, the 235 tests improved performance, 2 regressed and 705 were unchanged. That seems very optimistic.

Hi Geoff, How was it handled before your change? Were we just lucky that insert points always matched? Would it be possible to move all the logic for finding a proper insertion into SCEVExpander? I think that is ultimately the best solution for this, but I have to admit I looked into this code a while ago. Michael > On Mar 23, 2016, at 9:22 AM, Geoff Berry via llvm-dev <llvm-dev at

Which cases does this pass handle which aren't otherwise optimized out by passes like GlobalValueNumbering or DeadCodeElimination? Thanks, Jake VanAdrighem On Thu, Sep 10, 2015 at 2:35 PM, Steve King <steve at metrokings.com> wrote: > Hello LLVM, > It seems this thread has gone cold. Is there some low risk way for > the community to take the new pass for a test drive? >

> On Apr 30, 2018, at 1:49 PM, Se Jong Oh <sejooh at microsoft.com> wrote: > > Hi Jonas, > > I have another case that DBG_VALUE is not produced. I would appreciate it if you could take a quick look at the testcase below. > > > test code: > > llc -mtriple=aarch64 -stop-after=livedebugvalues -o - test.ll > > ; Function Attrs: nounwind ssp uwtable >

Hi Andy, Actually, if we just add hooks that preserves the existing behavior, It is not difficult. For example, For case one, we can define one function like virtual const SCEV* getTargetPreferredWinnerReg(const SCEV*& ScaledReg, SmallVector<const SCEV *, 4>& BaseRegs, GlobalValue*& BaseGV) const; In NarrowSearchSpaceByPickingWinnerRegs, we can

> On May 27, 2016, at 2:50 PM, via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > Hello, > > For a very simple loop where all IV users are post-inc users, I observed redundant add instructions in AArch64. > > From LSR debug, I can see initial formula for icmp is the one that transformed to a post-inc form in OptimizeLoopTermCond() and later expanded in post-inc