similar to: [LLVMdev] Value liveout (uses)

Thank you. Is it possible to determine the liveout of the operands (see example bellow) ? %5 = add i32 %4, %3 For '%5': i can simply use " i->isUsedOutsideOfBlock() " For '%3' and '%4' : this is the question ... >From your answer, is it possible to determine *which* value is liveout ( in binary instruction)? On Sat, May 30, 2009 at 2:57 AM,

On May 29, 2009, at 11:37 PM, Rotem Varon wrote: > How can i know, if a value have uses outside of the current basic > block (liveout), without iterating through all the basic block ? If the value is created within the basic block in question, and the block doesn't loop to itself, then you can just iterate through the uses and note if the use is an instruction in a different

I believe Dan has added a pass to compute livein / liveout values. Evan Sent from my iPhone On May 30, 2009, at 5:03 AM, Rotem Varon <varonrotem at gmail.com> wrote: > Thank you. > > Is it possible to determine the liveout of the operands (see example > bellow) ? > > %5 = add i32 %4, %3 > > For '%5': i can simply use "

The pass you're referring to is in include/llvm/Analysis/LiveValues.h and lib/Analysis/LiveValues.cpp. It computes conservative approximations for specific liveness queries, rather than full livein/liveout information. It's intended to be used as a heuristic. Dan On May 30, 2009, at 3:51 PM, Evan Cheng wrote: > I believe Dan has added a pass to compute livein / liveout values. >

On May 30, 2009, at 5:03 AM, Rotem Varon wrote: > Is it possible to determine the liveout of the operands (see example > bellow) ? > > %5 = add i32 %4, %3 > > For '%5': i can simply use " i->isUsedOutsideOfBlock() " > For '%3' and '%4' : this is the question ... By definition, operands are live out if they're used in any

" All of these answers are things you would do for an individual LLVM "Value". " I am sorry, but may be i am missing something here. In the previous email you suggested the function "bool isLiveOut(Instruction* I) ". So, if you please, explain how i can find out if a llvm::Value (not an llvm::Instruction) is live out or not. As i understand it, isLiveOut can help me

Hello all; So here is my goal: *** If there is a Call instruction to myFunction(int * val), I need to identify all the instructions that uses val in the IR and replace the uses with a newly created pointer. I will also be changing the argument of myFunction to the new pointer. int * val = malloc/calloc; ... myFunction(val); .... *val = 45; becomes== int * val = malloc/calloc; int * val1 =

Is there an easy way to obtain all liveout variables of a basic block? Liveins can be found for each MachineBasicBlock, but I can only find liveouts for the whole function, at MachineRegisterInfo. Do I need to find them out manually?

Because I feel bad for giving a non-answer: An easy way to find if a virtual register is alive after the basic block is to While iterating over the virtual registers - Check to see if the virtual register's "next" value exists outside of the basic block. for instance: std::vector<unsigned> findLiveOut( MachineBasicBlock * mbb ) { std::vector<unsigned> liveout; for(

I think I understood the problem you're trying to solve. I didn't, however, understand the problems you are having (maybe you're not running mem2reg?). I do have a little piece of code that I think does (more or less) what you want. Take a look at it, try understanding it, and see if it helps you out. You might have to change it a bit since you're replacing uses after an

Thanks for the reply. For the source code: int main() { int a = 0; int *p; p = &a; call_arnamoy(p); int *p1; p1 = p; return 1; } The bit code: %retval = alloca i32, align 4 %a = alloca i32, align 4 %p = alloca i32*, align 8 %p1 = alloca i32*, align 8 store i32 0, i32* %retval store i32 0, i32* %a, align 4 store i32* %a, i32** %p, align 8 %0 = load i32** %p, align 8 %call = call i32

Say I want to find all LLVM Value*-es that a live on exit from a basic block. What's the best way? - The 'LiveRange', 'LiveVariables' and 'LiveIntervals' classes seem to be tied to register allocation. - The ./lib/Target/SparcV9/LiveVar/FunctionLiveVarInfo.h file seem to provide what I need, but it's no a public header. - Volodya

On Feb 1, 2011, at 1:34 PM, Andrew Trick wrote: > On Feb 1, 2011, at 1:08 PM, Andrew Clinton wrote: > >> I have a (non-entry) basic block that contains only PHI nodes and an >> unconditional branch (that does not branch to itself). Is it always >> possible to merge this block with it's successor and produce a >> semantically equivalent program? I'm

In LiveIntervals::processImplicitDefs() we have this: for (MachineRegisterInfo::use_iterator UI = mri_->use_begin(Reg), UE = mri_->use_end(); UI != UE; ) { MachineOperand &RMO = UI.getOperand(); MachineInstr *RMI = &*UI; ++UI; MachineBasicBlock *RMBB = RMI->getParent(); if (RMBB == MBB) continue; const

On Wed, 11 May 2005, Alkis Evlogimenos wrote: > On Wed, 2005-05-11 at 13:17 -0500, Chris Lattner wrote: >> On Wed, 11 May 2005, Vladimir Prus wrote: >>> Say I want to find all LLVM Value*-es that a live on exit from a basic block. >>> What's the best way? >>> >>> - The 'LiveRange', 'LiveVariables' and 'LiveIntervals' classes

Here's what I've got so far - it seems to work, aside from the fact that DeleteDeadPHIs is not removing at least one dead PHI in my test program. --------------------- static bool mergeBlockIntoSuccessor(BasicBlock *pred, BasicBlock *succ) { if (succ == pred) return false; if (pred->getFirstNonPHI() != pred->getTerminator()) return false; //

On Jul 17, 2009, at 7:57 AM, David Greene wrote: > In LiveIntervals::processImplicitDefs() we have this: > > for (MachineRegisterInfo::use_iterator UI = mri_->use_begin(Reg), > UE = mri_->use_end(); UI != UE; ) { > MachineOperand &RMO = UI.getOperand(); > MachineInstr *RMI = &*UI; > ++UI; > MachineBasicBlock *RMBB

On May 11, 2005, at 3:03 PM, Chris Lattner wrote: > On Wed, 11 May 2005, Alkis Evlogimenos wrote: >> On Wed, 2005-05-11 at 13:17 -0500, Chris Lattner wrote: >>> On Wed, 11 May 2005, Vladimir Prus wrote: >>>> Say I want to find all LLVM Value*-es that a live on exit from a >>>> basic block. >>>> What's the best way? >>>>

I now understand that IndVarSimplify.cpp is capable of reproducing array references when the pointer initialization from the array address is found inside the immediately enclosing loop, such that in the following code: int A[20000], B[100], Z; int main() { int i, j, *a, *b; for ( a = &A[0], i = 0; i != 200; i++ ) for ( b = &B[0], j = 0; j != 100; j++

I am getting a segmentation fault as soon as I touch the Basic block *b value defined as :  std::string getPHIAssigns(const PHINode *PH)  { const BasicBlock *b = PH->getParent();    errs() << b->size(); where as getPHIAssigns is being called from               for (BasicBlock::iterator ins=b->begin(), e3=b->end(); ins!=e3; ++ins, ++l) // get instructions