similar to: [LLVMdev] DominanceFrontier for MachineBB

Tobias, Thanks for taking the time to summarize all this. It's a great writeup. I'm moving the thread to llvm-dev. My responses below. On May 21, 2012, at 5:06 AM, Tobias Grosser <tobias at grosser.es> wrote: > First of all some information about the RegionInfo pass: > > ======================================================================= > The very first paper I

Hi George, > I saw in the API that DominanceFrontier has been deprecated. Is this for real? > I have read the computational issues but shouldn't that be left to the users of > llvm? > My concern is I am writing a Control Dependence module that uses > Dominance-Frontier information. > Getting rid of Dominance Frontiers will put me in a tight spot. if the dominancefrontier

Hi Tobias, Thanks a lot for the detailed reply. I am working on several new optimizations for OpenCL kernels for a DSP architecture. The project itself has an NDA associated with it, so I cannot go into more details, but the source will be open to public after completion. One of the first steps is to serialize the work-items in a work-group (e.g., insert nested loops around REGIONs in

George Baah <georgebaah at gmail.com> writes: > Hi Guys, > > I saw in the API that DominanceFrontier has been deprecated. Is this > for real? > I have read the computational issues but shouldn't that be left to the > users of llvm? > My concern is I am writing a Control Dependence module that uses > Dominance-Frontier information. > Getting rid of Dominance

Hi Guys, I saw in the API that DominanceFrontier has been deprecated. Is this for real? I have read the computational issues but shouldn't that be left to the users of llvm? My concern is I am writing a Control Dependence module that uses Dominance-Frontier information. Getting rid of Dominance Frontiers will put me in a tight spot. George -------------- next part -------------- An HTML

Hi fellows, I am writing to ask what is the algorithm implemented in LLVM's RegionInfo.h/cpp. In the header file "RegionInfo.h", it says "Calculates a program structure tree built out of single entry single exit regions (defined in a 1994 paper called "The Program Structure Tree"). ... ... The algorithm to calculate these data structures however is COMPLETELY

Hello, I have a transform that, given a function F, will produce a new function G such that the basic blocks of G are (copies of) a subset of the basic blocks of F, and such that control flow is connected as you would expect. Given DominatorTree and DominanceFrontier of F, I would also like to efficiently compute DominatorTrees and DominanceFrontiers of G. I understand how to do this

Hi Tobias, If the PHI node at exit block of region R has multiple inputs from the R, I split the exit block into 2. The first block contains all PHI nodes whose input are all from the region. The second is the new exit node. All branches (outside R) to the old exit now point the new exit. All regions whose exit is the old exit are also updated with the new exit node. It works like a charm.

Thanks very much for the quick response. I have read the text many times, but it was not very clear to me why checking the two conditions involving dominance frontiers is equivalent to proving the pair {entry, exit} defines a refined region. I was asking for an mathematical proof really. It sounds to me like there should be a theorem or two in the graph theory endorsing it. Or do you mean, the

On 03/07/2010 11:09 AM, Jochen Wilhelmy wrote: > Hi! Hi Jochen, > I'd like to find the point where the control flow joins after a branch. > > e.g. if I have the following function > > if (a< b) > foo1(); > else > foo2(); > bar(); > > Then the control flow splits at the basic block containing a< b with > a branch as terminator

On Sun, Nov 3, 2013 at 1:02 AM, Daniel Berlin <dberlin at dberlin.org> wrote: > Is there a reason this is better than the modified algorithm created > by Ferrante? > It looks like yours has as bad a worst case time bound in reality. > That is, the algorithm runs in O(sum of the size of all the dominance > frontiers). > > http://www.cs.rice.edu/~keith/Embed/dom.pdf >

On Sun, Nov 3, 2013 at 1:02 AM, Daniel Berlin <dberlin at dberlin.org> wrote: > As for a "better" way to implement PRE, it depends on what algorithm > you want to use. If you just want to write a PRE pass, that's easy > enough without dominance frontiers. > I simply want to write a PRE pass to get a better understanding of the transformation. Any tips on where to

On Sun, Nov 3, 2013 at 9:19 AM, Christopher Wood <christopherwood07 at gmail.com> wrote: > On Sun, Nov 3, 2013 at 1:02 AM, Daniel Berlin <dberlin at dberlin.org> wrote: >> >> As for a "better" way to implement PRE, it depends on what algorithm >> you want to use. If you just want to write a PRE pass, that's easy >> enough without dominance

Hi , It will be good ,If you get us the sample that assert. Thanks ~Umesh On Tue, Jul 31, 2012 at 11:40 AM, 田中 太郎 <dontforgettobringatowel at live.jp>wrote: > > Hi all, > > I ran across an assertion failure while using region analysis in my passes. > I get the same thing when doing: opt -regions -analyze > > [...] > [1] entry => if.end > End region tree

Hi all, I ran across an assertion failure while using region analysis in my passes. I get the same thing when doing: opt -regions -analyze [...]   [1] entry => if.end End region tree Printing analysis 'Detect single entry single exit regions' for function 'njDecodeSOF': Region tree: [0] entry => <Function Return>   [1] entry => return     [2] if.end => return

Hi, I'm not able to answer your question. I'm wondering if you can create your own if it is just your own hobby project, or a project that you don't have to commit to the main repository. Creating DominatorFrontier seems to be expensive. However, if you are using bit-vector to represent a basic-block-set, I guess it can be done in linear time in practice. Following is the

On 03/16/2010 05:02 PM, James Stanier wrote: > > Hi Trevor, > > I just studied your diagrams -- I *think* that the "control tree" of > structural analysis is not same as the "control flow tree" from your own > Java work. However, as you understand your work more than I do, I present > you with some fancy coloured diagrams that I drew that might help you

Dear all, while trying to build llvm with shared libraries using GCC (tested both in Ubuntu 14.04 and Ubuntu 16.04) as in cmake -G Ninja -DBUILD_SHARED_LIBS=ON I run into the following link error lib/Transforms/IPO/CMakeFiles/LLVMipo.dir/PartialInlining.cpp.o: In function `llvm::ForwardDominanceFrontierBase<llvm::BasicBlock>::ForwardDominanceFrontierBase()':

Hi all, Does anyone know how to recreate the DominanceFronter and PostDominanceFrontier structures using the API of the latest release? To my knowledge, these are needed to implement a PRE pass (as done in the past<https://llvm.org/svn/llvm-project/llvm/tags/RELEASE_13/lib/Transforms/Scalar/PRE.cpp>), but they were removed a while ago for efficiency reasons. Is there a better way to

Hi Tobias, My RegionSimplify pass adds new exit node for refined regions to convert them into simple region. However, the RegionInfo pass does not seem to recognize those changes. For example, in the attached file, bb4.region is supposed to be in the first region. My RegionExtractor pass required the extracted region to be simple. Should we modify RegionInfo or is their away to preserve the