similar to: [LLVMdev] ScalarEvolution::getSVECAtScope

Hi, Is it valid to query ScalarEvolution::getSCEVAtScope with a Value which is an Instruction inside the provided Loop? If so, I believe there is a bug in computeSCEVAtScope. Specifically: 04716     // If the scope is outside the addrec's loop, evaluate it by using the 04717     // loop exit value of the addrec. 04718     if (!AddRec->getLoop()->contains(L)) { 04719       // To

hi all, i have SCEVAddRec {{(32 + @edge.8265),+,32}<Loop0>,+,4}<Loop1> where Loop0 and Loop1 are brothers (loops at the same level of the loopnest), and Loop0 have a computable backedge taken count. when i call getSCEVAtScope({{(32 + @edge.8265),+,32}<Loop0>,+,4}<Loop1> , Loop1), it just give me a {{(32 + @edge.8265),+,32}<Loop0>,+,4}<Loop1>, instead of

On Jun 29, 2010, at 7:08 AM, ether zhhb wrote: > > why computeSCEVAtScope not try to get the operands in the current > scope like the function do with SCEVCommutativeExpr, like: > > if (const SCEVAddRecExpr *AddRec = dyn_cast<SCEVAddRecExpr>(V)) { > if (!L || !AddRec->getLoop()->contains(L)) { > ... > // Then, evaluate the AddRec. >

Hi, You may try function "getSCEVAtScope" of the ScalarEvolution analysis: /// getSCEVAtScope - Return a SCEV expression for the specified value /// at the specified scope in the program. The L value specifies a loop /// nest to evaluate the expression at, where null is the top-level or a /// specified loop is immediately inside of the loop. /// /// This method can be used to compute

Forwarding to the dev list, in case others ran into similar issues and/or have input on this topic. Bardia Mahjour ----- Forwarded by Bardia Mahjour/Toronto/IBM on 2020/03/30 02:25 PM ----- From: Bardia Mahjour/Toronto/IBM To: listmail at philipreames.com Cc: "Michael Kruse" <llvm at meinersbur.de> Date: 2020/03/26 11:47 AM Subject: Scalar Evolution Expressions Involving Sibling

> I'm not following your example.  If you have two sibling loops with the same parent, one will frequently, but not always dominate the other.  Can you give a specific example of when forming a recurrence between two siblings (without one dominating the other), is useful? The situation can happen with guarded loops or with a user guard like below: if (c) { for (i = 0; i < n; i++)

Thanks for sharing the known problem. I think to solve the problem properly, we need to fully understand why that assumption about dominance is there and the implications of removing it. It would be good if you could be more specific about your idea of nullptr or SCEV_unknown (eg which function would return those values and when), but returning nullptr from getAddExpr or getSCEVAtScope may be

Hi Fellows, The goal is to find the induction variable for a loop, where the induction variable increments with the multiplication, division or shift operations, like this one: sz = 8; do { ... ... sz = sz / 2; } while (sz) Is SCEV capable of detecting the induction variable 'sz' in this case? The code snippet I am using to solve the problem is for each basic-block in a

On May 5, 2011, at 5:11 AM, Rotem, Nadav wrote: > Malveeka, > > You can use the LoopInfo analysis to find the induction variable. > > http://llvm.org/docs/doxygen/html/classllvm_1_1Loop.html#a72bbf45d2e00971f56bf8cfe4e1df01c > > Cheers, > Nadav getCanonicalInductionVariable is a good example of finding IVs without iterating over instructions. But you may need to

Hi Everyone, I''m trying to get Xen to use a native DRBD device but it seems it will not create the virtual machine. It does not seem to like the DRBD device type, any ideas on what might be wrong? I''m pretty sure my xen config file is OK and the DRBD device looks fine too. Full details below. xm create centostest Using config file "./centostest".

Hi Jimmy, It's good to know that the problem is not specific to the case I ran into. May be you can provide your example as well, since Philip seems to be interested in some specific examples. If the assertion in getAddrExpr is deemed necessary, then I think a condition check would be the next best solution as it helps client code guard against such cases and make alternative arrangements to

Originally on llvm-commits. On May 30, 2012, at 8:48 AM, Nuno Lopes <nunoplopes at sapo.pt> wrote: >> This is probably fine for now. It's a relatively safe use of SCEVExpander and the least effort approach, but generally I would like to encourage people to solve local rewrite problems with IRBuilder, not SCEVExpander, and build useful utilities for that purpose. Just because you

On Wed, 30 May 2012 10:04:50 -0700 Andrew Trick <atrick at apple.com> wrote: > Originally on llvm-commits. > > On May 30, 2012, at 8:48 AM, Nuno Lopes <nunoplopes at sapo.pt> wrote: > >> This is probably fine for now. It's a relatively safe use of > >> SCEVExpander and the least effort approach, but generally I would > >> like to encourage

Dear,Beg for your help. I am really puzzled with this problem.HVM domain can not boot up with Qcow incremental image(using command: qcow-create size incremental_file original_Qcow_img_file), but it can boot up with the original Qcow disk image file. When using Qcow incremental image, the guest qemu window would disappear before loading grub, and `xm list` can not find this guest domain.The VM

Hi All, In the attached test case there, is an unnested loop with 2 iterations. The loop latch block is terminated by an unconditional branch, so simplifycfg folds the almost empty latch block into its predecessor which is the loop header. This results in an additional backedge in the CFG, so when LoopRotate pass is called it canonicalizes the loop into a nested loop. However, now the loop

Hi, I am investigating a difference in code generation between release and assert builds of llvm. The culprit is IndVarSimplify that comes up with different behavior on the same input: in the assertion build, it does do an extra 'INDVARS: Rewriting loop exit condition' After digging around, it seems that following change is the culprit: ----- Author: Philip Reames <listmail at

On 6/30/2017 7:48 AM, Balaram Makam via llvm-dev wrote: > > Edit. Predecessor -> successor. > > *From:* llvm-dev [mailto:llvm-dev-bounces at lists.llvm.org] *On Behalf > Of *Balaram Makam via llvm-dev > *Sent:* Friday, June 30, 2017 10:47 AM > *To:* llvm-dev at lists.llvm.org > *Subject:* [llvm-dev] LoopSimplify pass prevents loop unrolling > > Hi All, > >

Hi, I wonder how many of you are familiar with scalar evolution pass. I met a problem regarding to the SCEVAddRecExpr. Say for the code: const int N = 100; int a[N]; for(int i=0;i<N;i++) a[i] = 0; For the access of a[i], the pass will transform this a[i] to a SCEVAddRecExpr <@a, +, sizeof(int)><BB_Name>, which means the access of the array `a' starts from the address `a' and

Hi Pankaj, On Sun, Feb 11, 2018 at 2:32 PM, Chawla, Pankaj <pankaj.chawla at intel.com> wrote: > Thanks for investigating the issue! > > I am more interested in getting the underlying problem fixed rather than making this particular test case work. I think I have more test cases where this problem crops up. I would any day prefer consistent results over compile time savings which

Dear All, Is the following patch to ScalarEvolution correct? It seems that without it, the enclosing for loop could skip over SCEVAddRecExpr's in the Ops[] array. -- John T. -------------- next part -------------- An embedded and charset-unspecified text was scrubbed... Name: scpatch URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20080222/3ff8edd7/attachment.ksh>