search for: loopsimplifi

On Wed, Jan 22, 2014 at 1:01 AM, Andrew Trick <atrick at apple.com> wrote: > On Jan 22, 2014, at 12:44 AM, Chandler Carruth <chandlerc at gmail.com> > wrote: > > > On Wed, Jan 22, 2014 at 12:33 AM, Andrew Trick <atrick at apple.com> wrote: > >> > There appear to be two chunks of "functionality" provided by loop >> passes: >> >

On Wed, Jan 22, 2014 at 12:33 AM, Andrew Trick <atrick at apple.com> wrote: > > There appear to be two chunks of "functionality" provided by loop passes: > > > > 1) A worklist of loops to process. This is very rarely used: > > 1.1) LoopSimplify and LoopUnswitch add loops to the queue. > > I’m making this up without much thought, but we may benefit

On 6/30/2017 11:38 AM, Balaram Makam wrote: > > Thanks Eli, > > I was looking at this code which keeps track of loop headers but is > checking if the destination of branch is a loop header sufficient? > This prevents merging empty preheaders into the loop headers as well. > There isn't really any reason to collapse preheaders anyway; LoopSimplify will recreate them,

I will try to reduce a test case for the regression I found and will update. Thanks, Balaram From: Friedman, Eli [mailto:efriedma at codeaurora.org] Sent: Friday, June 30, 2017 2:54 PM To: Balaram Makam <bmakam at codeaurora.org>; llvm-dev at lists.llvm.org Subject: Re: [llvm-dev] LoopSimplify pass prevents loop unrolling On 6/30/2017 11:38 AM, Balaram Makam wrote: Thanks Eli,

Hello, LoopSimplify try to separate a loop with multiple backedges into a nested loop (an outer loop and an inner loop). Naturally, this kind of a loop corresponds to a single loop in source code. I can see this could be useful for cases described in the comments in lib/Transforms/Utils/LoopSimplify.cpp, which looks like a corner case. For most cases, how does this help ? Junjie

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, > >

See http://llvm.org/docs/GettingStarted.html#brokengcc and then try building with something OTHER than GCC 4.1.2 . ----- Original Message ---- > From: Nick Johnson <npjohnso at cs.princeton.edu> > To: LLVM Developers Mailing List <llvmdev at cs.uiuc.edu> > Sent: Monday, May 11, 2009 3:01:12 PM > Subject: [LLVMdev] Pass Manager hangs with CallGraph and LoopSimplify >

Hello, I have discovered a situation in which the pass manager will infinite loop. The minimal test case is below this message. The required structure of these passes is; Before requires CallGraph After requires LoopSimplify and Before I can observe this through opt: opt -load ./libBug.so -after input.bc -o output.bc I built my copy of llvm from svn revision 68820 using gcc 4.1.2 Any

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

Okay, the problem with this cycle is LoopSimplify. It is using AliasAnalysis which is where that _ZN4llvm11BasicAAStubEv symbol is coming from. It seems to me that LoopSimplify.cpp is in the wrong place. This file defines the LoopSimplify FunctionPass which doesn't seem to me to be a "transform util". I thought the purpose of "Transforms/Util" was to provide utilities

Hello. I am trying to create my own LoopVectorize.cpp pass as a separate pass from the LLVM trunk, as described in http://llvm.org/docs/CMake.html#embedding-llvm-in-your-project. Did anybody try something like this? I added close to the end of the .cpp file: /* this line seems to be required - it allows to run this pass as an embedded pass by giving opt -my-loop-vectorize

Tobias, I am working on one very well hidden issue with Polly loop structure. Here is a brief description. In polly::createLoop() we create something like this (topology is important): polly.start: ; preds = %polly.split_new_and_old ... <some code> br label %polly.loop_header polly.loop_after: ; preds =

So, there are two primary ideas behind SSA form management in the loop optimizers of LLVM: - Require LCSSA form input, leverage its (very powerful) guarantees to simplify maintaining SSA form, and also maintain LCSSA form. - Don't bother with LCSSA form input, assume the worst, and use powerful incremental SSA formation utilities built on SSAUpdater to form SSA on demand when needed. (Note,

Just noticed that quite a few passes like LoopSimplify are implemented in a single .cpp file ... this makes it impossible to specify LoopSimplify using the "addRequired" method. Was there any particular reason to do it this way? I wouldn't mind doing the splitting myself, though I am not using the CVS versions right now. Also, it would be nice to have support for some sort of a

On Thu, Apr 28, 2005 at 11:22:26PM -0500, Chris Lattner wrote: > BasicBlock *SplitBlockPredecessors(BasicBlock *BB, const char *Suffix, > const std::vector<BasicBlock*> &Preds); > > Basically, given a BB with multiple predecessors, it inserts (and returns) > a new block, moving the predecessors in Preds to the new block and leaving

Okay, its not that simple. Several files in Transforms/Utils depend on things in lib/Analysis. A quick grep shows: BreakCriticalEdges.cpp:#include "llvm/Analysis/Dominators.h" BreakCriticalEdges.cpp:#include "llvm/Analysis/LoopInfo.h" CloneTrace.cpp:#include "llvm/Analysis/Trace.h" CodeExtractor.cpp:#include "llvm/Analysis/Dominators.h"

On 05/15/2013 07:08 PM, Sergei Larin wrote: > > Tobias, [..] > > ...or as always I might be missing a big picture here, and I appreciate if > you can explain the original intent. Hi Sergei, thanks for reporting this issue in so much detail. I am afraid there is no bigger story. For some reason the update of the LoopInfo was not included in the original patch of the code

Hi again, I come back to this issue with an example. It's a pass which does nothing but throw the 'Unable to schedule' error. namespace { struct MyPass : public FunctionPass { static char ID; // Pass identification, replacement for typeid MyPass() : FunctionPass(ID) { initializeMyPassPass(*PassRegistry::getPassRegistry()); } virtual void

I am reading the code for exit block transformation in loop simplify. I do not fully understand how exit blocks with out-of-loop dominators are transformed. In SplitLandingPadPredecessors, all the in-the-loop predecessors of the exits block are grouped and given to the .loopexit basic block and the out-of-loop predecessors are grouped and given to the .nonloopexit basic block. the .loopexit

Hi, I'm writing a function pass which is dynamically loaded by opt and I need some analysis and passes to be run before my pass: virtual void getAnalysisUsage(AnalysisUsage &AU) const { AU.addRequired<LoopInfo>(); AU.addPreserved<LoopInfo>(); AU.addRequiredID(LoopSimplifyID); AU.addPreservedID(LoopSimplifyID);