search for: getexitblocks

Hi, all. I'm using void LoopBase::getExitBlocks (SmallVectorImpl< BlockT * > &ExitBlocks) const to get all exit blocks for a loop. The problem I find with this API is that it returns repetitive basic blocks in certain situations. Should repetitive basic blocks be removed? I have an example to show the problem. Following is the source...

Hi, LoopBase::getExitBlocks in LoopInfo.h returns all exit basic blocks by iterating over all blocks of a loop and storing all branch targets that are outside the loop. This method allows for duplicates in the result vector, e.g.: Loop at depth 2 containing: %bb2<header><exit>,%bb1<latch>,%bb3<exit>...

On Apr 19, 2012, at 10:43 PM, xiaoming gu <xiaoming.gu at gmail.com> wrote: > Hi, all. I'm using void LoopBase::getExitBlocks (SmallVectorImpl< BlockT * > &ExitBlocks) const to get all > exit blocks for a loop. The problem I find with this API is that it returns repetitive basic blocks in certain > situations. Should repetitive basic blocks be removed? Users generally expect a unique set of exit blocks,...

On Apr 23, 2012, at 10:31 PM, Andrew Trick <atrick at apple.com> wrote: > > On Apr 19, 2012, at 10:43 PM, xiaoming gu <xiaoming.gu at gmail.com> wrote: > >> Hi, all. I'm using void LoopBase::getExitBlocks (SmallVectorImpl< BlockT * > &ExitBlocks) const to get all >> exit blocks for a loop. The problem I find with this API is that it returns repetitive basic blocks in certain >> situations. Should repetitive basic blocks be removed? > > Users generally expect a unique s...

hi, > Users generally expect a unique set of exit blocks, but don't make any > strong assumption. The worst that can happen is missed optimization or > redundant analysis. In most cases, the loop is in LoopSimplifyForm, so it's > probably not a problem in practice. > > > Another thing I should mention. The iteration order of ExitBlocks is > important. In llvm,

Hello all, I’m pretty new to LLVM. I'm writing a pass for loop optimization. I clone and rearrange loops, setting the cloned loop as the original loop’s parent. This can be done multiple times, until there is no more work to do. The trouble is, after the first time I do this, the cloned loop's SCEVs become unknown types when they should be AddRecExpr. If I re-run the whole pass on the

hi all, On 2010-1-7 0:11, John Mosby wrote: > In LLVM we could add support for generalized CFG regions and > RegionPasses. A region is a part of the CFG. The only information we > have is, that it has one entry and one exit, this it can be optimized > separately. > I think this is the best way to add region analysis. I must admit > this approach > helps me on another,

On 01/08/10 14:20, ether wrote: > sorry that i forgot to change the subjuect Hi ether, sounds interesting. Actually is/may be some kind of region. If you want you can have a look at the analysis, that I wrote. It is not yet finished, not completely documented and work in progress. However the first big comment might be interesting for you. Or seeing the results of opt -regions -analyze

Why not use the "standard" algorithm for detecting SESE-regions and building a program structure tree? It should handle everything you want. It also becomes much simpler to specify a connected SESE-region by entry/exit edges, while a disconnected region is specified by entry/exit blocks. Only defining regions on blocks is not enough to be able to quickly determine how to replace/move a

On 01/08/10 14:20, ether wrote: > sorry that i forgot to change the subjuect > > > hi all, Hi ether, now a kind of more complete answer. > On 2010-1-7 0:11, John Mosby wrote: >> In LLVM we could add support for generalized CFG regions and >> RegionPasses. A region is a part of the CFG. The only information we >> have is, that it has one entry and one exit, this

...do quick >>> +    // lookups. >>> +    SmallVector<BlockT*, 128> LoopBBs(block_begin(), block_end()); >>> +    std::sort(LoopBBs.begin(), LoopBBs.end()); >> >> Would it be better to use a DenseSet for this lookup? > Well, its the same that is used in getExitBlocks() where I got the implementation from. I really don't know but I think the current implementation is okay from what I gather form the LLVM Programmer's Manual. There is nothing wrong with it, but using a DenseSet has better asymptotic performance and shortens the code. OTOH it may have a h...

...can use binary search to do quick >> + // lookups. >> + SmallVector<BlockT*, 128> LoopBBs(block_begin(), block_end()); >> + std::sort(LoopBBs.begin(), LoopBBs.end()); > > Would it be better to use a DenseSet for this lookup? Well, its the same that is used in getExitBlocks() where I got the implementation from. I really don't know but I think the current implementation is okay from what I gather form the LLVM Programmer's Manual. >> --- llvm-van/include/llvm/Analysis/MaximumSpanningTree.h 1970-01-01 01:00:00.000000000 +0100 >> +++ llvm-c7/in...

Hi, It's been a while since I sent the last compile time report [1], where it was shown that LLVM was getting slower over time. But now I'm happy to bring some good news: finally, LLVM is getting faster, not slower :) *** Current status *** Many areas of LLVM have been examined and improved since then: InstCombine, SCEV, APInt implementation, and that resulted in almost 10% improvement

Hi Andreas, First, thanks again for undertaking this work and submitting it back. There is a lot of good stuff here and it would be great to see it get back into the tree. I have a few major high-level comments on the patch. First off, the patch is quite large and should be broken down into separate incremental changes which are easier to review and apply. I think the patches should more or less

Hi all, as proposed in http://lists.cs.uiuc.edu/pipermail/llvmdev/2009-February/020396.html I implemented the algorithm presented in [Ball94]. It only instruments the minimal number of edges necessary for edge profiling. The main changes introduced by this patch are: *) a interface compatible rewrite of ProfileInfo *) a cleanup of ProfileInfoLoader (some functionality in ProfileInfoLoader