similar to: [LLVMdev] CodeExtractor.cpp potential bug?

On Dec 31, 2010, at 11:20 AM, Vu Le wrote: > There might be a misuse of DominatorTree::splitBasicBlock in CodeExtractor.cpp, line 145. > Header is splited into two (OldPred->NewBB). > > Line 145 updates the dominator tree by calling DT->splitBasicBlock(NewBB). > I think it should be DT->splitBasicBlock(OldPred). > > When I tried to extract a code region whose

I forgot to cc llvmdev. Here is my original message. I'm a bit confused on DominatorTreeBase::Split() ( http://llvm.org/docs/doxygen/html/Dominators_8h_source.html#l00229) If a basic block A splits into A->B, when I call Split(), which is NewBB? A or B? The semantics shows that NewBB is the newly split basic block B. But the assertion at line 229 doesn't seem right. 00229

Hello, The CodeExtractor contains a std::set<BasicBlock*> to keep track of the blocks to extract. Iterators on this set are not deterministic, and so the functions that are generated are not (the order of the inputs/outputs can change). The attached patch uses a SetVector instead. Ok to apply ? Thanks, Julien -- Julien Lerouge PGP Key Id: 0xB1964A62 PGP Fingerprint: 392D 4BAD DB8B CE7F

Hi folks, Hope this is not a silly question. But it bothers me when I am thinking about it. My question is: 1. In the implementation of serverSplitPHINodes(), why it only checks the first PHI node for possible multiple inputs from outside the region to extract. There could be more than one PHI nodes in the header block, and the code only checks the first one. I don't quite get it.

Hi, I found a problem in CodeExtractor::severSplitPHINodes() <CodeExtractor.cpp>. The algorithm first separates the header block into two, one containing only PHI nodes and the other containing the remaining non-PHI nodes. The variable NewBB holds the pointer to the latter half block. Later, it tries to update DT information. if (DT) DT->splitBlock(NewBB); In splitBlock, it checks

On Nov 19, 2008, at 7:41 AM, Jack Tzu-Han Hung wrote: > Hi, > > I found a problem in CodeExtractor::severSplitPHINodes() > <CodeExtractor.cpp>. > > The algorithm first separates the header block into two, one > containing only PHI nodes and the other containing the remaining non- > PHI nodes. The variable NewBB holds the pointer to the latter half > block.

Hi Devang, Thanks for your reply. But if you look at the comment of BasicBlock::splitBasicBlock(), it says that "...an unconditional branch is added to the new BB, and the rest of the instructions in the BB are moved to the newBB, including the old terminator." So, the terminator of the newBB is exactly the same as the terminator of the oldBB. IF the oldBB has multiple successors,

On Jan 8, 2010, at 5:01 PM, Julien Lerouge wrote: > Hello, > > The CodeExtractor contains a std::set<BasicBlock*> to keep track of > the > blocks to extract. Iterators on this set are not deterministic, and so > the functions that are generated are not (the order of the > inputs/outputs can change). > > The attached patch uses a SetVector instead. Ok to apply ?

I'm having an issue with the CodeExtractor. When I try to extract the lone basic block from the following function, I get an assertion error. define i32 @test(i32 %x) { %tmp = call i32 @test3( i32 %x ) ; <i32> [#uses=1] ret i32 %tmp } The assertion error is: lli: Dominators.cpp:71: void llvm::DominatorTree::splitBlock(llvm::BasicBlock*): Assertion

Hi All, I’m currently working on a simple task which needs to transform loops into tail-recursive functions. I found the CodeExtractor class a handy helper to use, but later encountered a problem. Consider the following CU struct S { int a, b; }; int foo(struct S *s, unsigned n) {   struct S *next = s;   unsigned i;   for (i = 0; i < n; ++i) {     if (!s[i].a)      

I am working on a pass to extract small regions of code to run somewhere else (different node in a cluster). Basically what I need is the ability to isolate a region of code, get its inputs and outputs, create a new function with the extracted code and code aggregating the in and out parameters as structs that can be cast for a “void*”-based interface. It looks like the CodeExtractor

Hi, I want to insert a conditional branch in the middle of a basic block. To that end, I am doing these steps: (1) Split the basic block: bb->splitBasicBlock() (2) Remove the old terminator: succ->removePredecessor(bb) bb->getTerminator()->getParent() (3) Adding a new terminator: BranchInst::Create(ifTrue, ifFalse, cnd, "", bb); That seems to work, but later passes

On Thu, Oct 30, 2014 at 2:33 PM, Robin Morisset <morisset at google.com> wrote: > Hi, > > From my understanding of the LLVM IR, it is impossible to jump to the > middle of a Basic Block, only to its beginning. But there is a > splitBasicBlock function that seems like it might be useful to you, to make > sure a basic block is starting at the exact place you want to jump.

On Wed, May 2, 2012 at 1:57 AM, Dmitry N. Mikushin <maemarcus at gmail.com>wrote: > At KernelGen we have an out-of-tree variation of CodeExractor called > BranchedCodeExractor [1], which instead of taking a code region into a new > function, does it conditionally: > OK... as this is an out-of-tree branch of the code extraction, nothing I'm planning should negatively impact

Hi Brandon, > Did you have issues with the Verifier complaining about function-local > metadata after moving blocks? Did you find a good solution for this? > It looks like you are moving blocks or instructions with attached metadata to another function. Some metadata is function-specific, so the verifier complains because the instruction/BB and the metadata don't belong to the

On 18/11/13 21:43, Brandon Holt wrote: > I am working on a pass to extract small regions of code to run > somewhere else (different node in a cluster). Basically what I need is > the ability to isolate a region of code, get its inputs and outputs, > create a new function with the extracted code and code aggregating the > in and out parameters as structs that can be cast for a

Thanks for reply Chuck. Please excuse me if I'm not supposed to reply to all. Are you saying all PHI nodes are required to include all its predecessor blocks no matter they have input or not? What about successor blocks? Are they optional if they don't provide inputs? BTW, where should I look at to verify this, the mem2reg.cpp & PromoteMemToReg.cpp? Thanks a lot. On Sat, Mar 2, 2013

On Thu, Oct 30, 2014 at 4:48 PM, Eric Christopher <echristo at gmail.com> wrote: > > > On Thu Oct 30 2014 at 1:16:38 PM Xiaoguang Wang <xgwang09 at gmail.com> > wrote: > >> On Thu, Oct 30, 2014 at 2:33 PM, Robin Morisset <morisset at google.com> >> wrote: >> >>> Hi, >>> >>> From my understanding of the LLVM IR, it is

On Fri, Jan 08, 2010 at 05:04:17PM -0800, Chris Lattner wrote: > On Jan 8, 2010, at 5:01 PM, Julien Lerouge wrote: > >Hello, > > > >The CodeExtractor contains a std::set<BasicBlock*> to keep track > >of the > >blocks to extract. Iterators on this set are not deterministic, and so > >the functions that are generated are not (the order of the >

Hi Dean, Thanks for your reply. That's exactly what I am doing, but I was looking for a default optimization or pass implementation if there was. I used BasicBlock::splitBasicBlock() but it puts "br" end of original basic block. I tried to delete the br instruction by using eraseFromParent() but it didn't work. I had to rewrite my own splitBasicBlock() by modifying the