similar to: [LLVMdev] An unexpected behavior in RegionInfo's block_iterator

Hi Tobias, Thanks so much for the quick response. Your approach fixes the issue. On a bigger context, would it make more sense to make the region exit part of the region? For example, a while loop gets lowered down to LLVM IR contains while.cond, while.body and while.end. If one tries to use RegionInfo as a substitute for structural analysis, she might think while.end should belong to

On Fri, May 2, 2014 at 5:30 PM, Tobias Grosser <tobias at grosser.es> wrote: > On 03/05/2014 00:15, Paul Vario wrote: > >> Hi Tobias, >> >> Thanks so much for the quick response. Your approach fixes the >> issue. >> On a bigger context, would it make more sense to make the region >> exit >> part of the region? For example, a while

Hi I have checked all blocks, each block have a Terminator instruction and each blocks belongs to a function. I'm really confused. I guess the problem is caused by the removal of the Loop,The code is as follows: * //every block to header (except the ones in the loop), will now redirect to newblock for (pred_iterator PI = pred_begin(header); PI != pred_end(header); ++PI) {

I would delete the Loop. I used the following code. cout << "begin to delete loop" << endl; for (Loop::block_iterator bi = L->block_begin(), bi2; bi != L->block_end(); bi = bi2) { bi2 = bi; bi2++; BasicBlock * BB = *bi; for (BasicBlock::iterator ii = BB->begin(), ii2; ii != BB->end(); ii= ii2) { ii2 = ii;

Hello; I wrote this simple loop pass to collect the number of instructions in each loop of the program. The code is as follows- #define DEBUG_TYPE "loopinst" #include "llvm/Pass.h" #include "llvm/Analysis/LoopPass.h" #include "llvm/Support/raw_ostream.h" #include "llvm/ADT/Statistic.h" #include "llvm/Instructions.h" #include

On 12/1/2012 10:02 AM, James Molloy wrote: > > I'm proposing a new function attribute, "noclone", with the semantics that "calls to functions marked "noclone" cannot be cloned or duplicated into the same function.". That is, it is illegal to call J = I->clone() then attach J to the same basic block as I if I is marked "noclone". The class Loop

Problem solved. I was building llvm in a separate llvm-build directory. I built it within the llvm-src directory (which kept all the llvm .so and my pass' .so in the llvm-src/Release+Asserts/lib directory) to solve the problem. Can anyone tell me what's the difference between writing a pass as a "struct" (as in the tutorial) and as a "class" (as most developers do)?

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

Hi, > Problem solved. I was building llvm in a separate llvm-build directory. I > built it within the llvm-src directory (which kept all the llvm .so and my > pass' .so in the llvm-src/Release+Asserts/lib directory) to solve the > problem. I do not fully understand what you mean, there should be no difference on building out of source AFAIK. > Can anyone tell me what's

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

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

Hi Tobi, I have one additional question about the RegionInfo::isRegion function. In the second case (i.e. Entry dominates Exit), why is checking the following two conditions are equivalent to checking it's a refined region: For any BB in DF(exit), 1) BB should be in DF(entry) 2) BB reachable only from entry through a path passing exit.

hi i want replacing a global variable by a constant value for erase instruction. i had seen the code that as follows for (llvm::GlobalVariable::use_iterator U = gv->use_begin(); U != gv->use_end();--U ) { llvm::Instruction *I = llvm::cast<llvm::Instruction>(U); I->replaceAllUsesWith(constPtr); I->eraseFromParent(); } but i dont know how can declare constptr.

Hi nada, > i want replacing a global variable by a constant value for erase instruction. I'm not sure what you mean exactly. A GlobalVariable has pointer type. Do you want to replace that pointer by a constant pointer? Or is it rather that you want to say that the contents of the memory pointed to by the GlobalVariable is constant, and have all places that load that GlobalVariable

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

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:

Hi, OpenCL has a "barrier" function with very specific semantics, and there is currently no analogue to model this in LLVM. This has been touched on by the SPIR folks but I don't believe they put forward a proposal. The barrier function is a special function that ensures that all workitems executing a kernel have executed up to that point before execution on any workitem can

Hi, I want to write a pass that pulls single-entry a single-exit (SESE) region into a function. The idea is similar to extracting a loop in LoopExtractor.cpp. Basically, for each region that meet our criteria, 1. Find all basic blocks in that regions 2. Call llvm::ExtractCodeRegion() to replace that region by a call to the extracted function. 3. Delete the region from the RegionPassManager queue

> Maybe a similar interface could be added to Instruction, and an > instruction would declare itself unsafe to clone if it was a call to a > function with the attribute that you are proposing. I experimented with something similar to this, where Instruction::clone ensured it wasn't "noclone" - if it was, it asserted. But that broke the use-case of cloning whole functions.

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 =