similar to: [LLVMdev] First time!

Hi aditya, There are two ways to cound the number of predecessors for each basic block. You can generate the control flow graph using the CallGraphScc pass with the granularity of basic block and can simply traverse the graph bottom up till the root. The number of nodes encountered would be the number of predecessors. The second way would be to use the special ;preds marker in the llvm IR. Each

Hi all, Is there a way to walk through ALL the predecessors of a basic block in a CFG. I tried to iterate over the preds using this method for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++I) { BasicBlock *PredBB = *PI; } but this only gives the immediate predecessors for a basic block. For example, in this sample control flow graph. entry -> bb1 -> bb2 -> bb4

Hi Pabhat, Have you checked out DepthFirstIterator? (include/llvm/ADT/ DepthFirstIterator.h). It provides an iterator abstraction to perform a forward/reverse DFS traversal of a graph. Many of the LLVM datatypes that represent graphs have a template specialization of the GraphTraits<> class which allows separate algorithms to treat them as graphs, walk them, etc. (Both BasicBlock

Hi, Well, yes i did try your suggestion but i keep on running into a compilation problem. The error is: llvm[0]: Compiling Hello.cpp for Release build (PIC) /home/saraswat/llvm/llvm-2.1/include/llvm/ADT/GraphTraits.h: In instantiation of `llvm::GraphTraits<llvm::ilist_iterator<llvm::BasicBlock> >': Hello.cpp:59: instantiated from here

hi, how to get the number of immediate predecessors for each basic block (arguements of remarks statement at the beginning of the basic block) thank you aditya ____________________________________________________________________________________ Never miss a thing. Make Yahoo your home page. http://www.yahoo.com/r/hs

I want to do the following: suppose the program structure: bb / \ bb1 bb2 \ / bb3

On May 22, 2014, at 3:51 PM, Chandler Carruth <chandlerc at google.com> wrote: > > On Thu, May 22, 2014 at 4:42 PM, Louis Gerbarg <lgg at apple.com> wrote: > The problem that the above transform is technically illegal because “When indexing into a (optionally packed) structure, only i32 integer constants are allowed (when using a vector of indices they must all be the same

I have created a new basic block. Now I want to make copy of instructions from one basic block to another . How to do that ? -- regards, soumya prasad ukil -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20101115/ddb0c4ab/attachment.html>

On Nov 14, 2010, at 12:13 PM, Soumya Prasad Ukil wrote: > I have created a new basic block. Now I want to make copy of instructions from one basic block to another . How to do that ? See CloneBasicBlock @ Transforms/Utils/Cloning.h - Devang

Hi, How does the requirement that phi instructions have one value per predecessor basic block interact with indirectbr instructions? For instance, take the following code: L1: br i1 %somevalue, label %L2, label %L3 L2: %ret1 = i8* blockaddress(@myfunction, %L5) br label %L4 L3: %ret2 = i8* blockaddress(@myfunction, %L6) br label %L4 L4: %ret = phi i8* [%ret1, L2], [%ret2, L3]

---------- Forwarded message ---------- From: Ryan Taylor <ryta1203 at gmail.com> Date: Mon, Nov 21, 2011 at 10:30 AM Subject: Re: [LLVMdev] Order of Basic Blocks To: Benjamin Kramer <benny.kra at googlemail.com> This worked, though the RPO_iterator apparently wasn't what I was looking for anyways, it seems it doesn't rreally go top->down. I have a simple example code,

Hi, All I want to implement DSWP Which is used for parallelization of loops. For this purpose, the loop was replaced with a new basic block in main function. And new functions were created and basic blocks of Loop assigned to them.I have checked blocks and branches for Succ and Pred relation and I have not found any problems. However I get the following error: * **opt:

> On Sep 21, 2016, at 2:23 PM, Daniel Berlin <dberlin at dberlin.org> wrote: > > > > // For all predecessors of this MBB, find the set of VarLocs that > // can be joined. > for (auto p : MBB.predecessors()) { > auto OL = OutLocs.find(p); > // Join is null in case of empty OutLocs from any of the pred. > if (OL == OutLocs.end()) >

Hi LLVM-devs, I am looking for a way to prevent an instruction to be executed more than once, or duplicated .. I know that by default everything can be duplicated, but is there a work-around? The structure of the code is BB1 BB2 | | | | | | |----------| | v BB3 where the first instruction in BB3 is inserting an inline assembly

Recently I posted a patch to migrate certain GEPs between basic blocks in cases where doing so would improve the ability of instcombine to merge into more complicated addressing mode (r209049 and r209065). After some build to failures it was rolled back. I now have a patch that no longer causes the regressions I was seeing, but it also no longer can optimize the case I was trying to optimize. As

Hi, this question might be a bit silly: apart from the language reference(http://llvm.org/docs/LangRef.html#switch-instruction) page, are there additional rules for a regular llvm frontend to generate llvm IRs? There are a few cases that I got from clang/llvm-gcc/dragonegg when compiling *C* source code into llvm IR: 1. It seems that there is ONLY ONE ReturnInst(and NO InvokeInst) for such llvm

On 08/05/2010 06:46 AM, Wenbin Zhang wrote: > Hi all, > I'm using postDominatorTree to do some program analysis. My code works > well for small tests, but when I run it on real applications, the > following error occurs: > /Inorder PostDominator Tree: DFSNumbers invalid: 0 slow queries. > [1] <<exit node>> {0,21} > [2] %bb1 {1,2} > [2] %bb {3,4} > [2]

Hi, all As I'm a Chinese, be patient of my poor description below. I compiled libgcc into llvm bitcode in both big endian and little endian. and got 2 different version of function: _ashldi3, the following is the fragment of this function: little endian: ============================================= ...... target datalayout =

> > > Conceptually, the LiveDebugValues data flow analysis should be using > three-valued logic arranged in a lattice > > ⊥ (uninitialized / don't know) > / \ > true false (is (not) available) > > where join(x, ⊥) = x, otherwise it behaves like boolean &. > > All debug variable values are initialized to the bottom element first. > After

Hi, On Mon, May 1, 2017 at 8:47 AM, Daniel Berlin via llvm-dev <llvm-dev at lists.llvm.org> wrote: >> Today, the IR requires that if you have multiple edges from A to B >> (typically with a switch) any phi nodes in B must have an equal number of >> entries for A, but that all of them must have the same value. > >> This seems rather annoying.... >> 1) It