search for: getcanonicalinductionvari

Hi I have the followed code for which I am writing a loop pass. int main() { int i = 0; for (i=0; i<20; i++) { printf ("hello world %d\n", i); } return 0; } In the function runOnLoop, I have the following instruction PHINode *indv = NULL; indv = L->getCanonicalInductionVariable(); However, when I check indv is always set to NULL. Since the code has a canonical induction variable, I was expecting the endv to start pointing to the induction var phi node. Please let me what I'm missing here Thanks Malveeka -------------- next part -------------- An HTML attachment...

...I am writing a loop pass. > > int main() { > int i = 0; > for (i=0; i<20; i++) { > printf ("hello world %d\n", i); > } > return 0; > } > > In the function runOnLoop, I have the following instruction > PHINode *indv = NULL; > indv = L->getCanonicalInductionVariable(); > > However, when I check indv is always set to NULL. > Since the code has a canonical induction variable, I was expecting the endv > to start pointing to the induction var phi node. > > Please let me what I'm missing here > > Thanks > Malveeka > > ______...

Forwarding to list :) ~Will ---------- Forwarded message ---------- From: Malveeka Tewari <mtewari at eng.ucsd.edu> Date: Sun, May 22, 2011 at 12:38 AM Subject: Re: [LLVMdev] getCanonicalInductionVariable To: willdtz at gmail.com Adding -mem2reg fixed the problem ! Thanks a lot! Malveeka On Sat, May 21, 2011 at 9:47 PM, Will Dietz <willdtz at gmail.com> wrote: > > Also, make sure you're running the necessary transform passes as well, > I've run into this testing my anal...

Hello . opt -indvars pass does not generate canonical induction variable.  (NULL == loop->getCanonicalInductionVariable();) PLEASE explain why? and how can I fix it? Thanks in advance, Edvard  -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20120724/92a28ed5/attachment.html>

I call this function and it returns only "i" in my example. Are there any ways to return "j" also? 2017-07-25 19:11 GMT+02:00 Michael Kruse <llvmdev at meinersbur.de>: > There is Loop::getCanonicalInductionVariable() > > You may need to run the "-indvars" (IndVarSimplify) pass before it > returns a value. I am not sure it normalizes the step size to 1 in all > cases. > > Michael > > 2017-07-25 18:12 GMT+02:00 Anastasiya Ruzhanskaya via llvm-dev > <llvm-dev at lists....

Hi, I was looking at trying to get loop induction variable at IR level. LLVM documentation mentioned indvars pass and getCanonicalInductionVariable() to get them, I tried running the indvars pass and then a custom pass which iterates through loops and uses the function to obtain variable for a simple loop program. But the API returns null. I also read in similar posts that the indvars pass is not available in the current version but docume...

...frtk.ru>: >> I call this function and it returns only "i" in my example. Are there any >> ways to return "j" also? > > That would contradict it being the /canonical/ induction variable, wouldn't it? > > If you look into the imlplementation of > getCanonicalInductionVariable(), it just walks the IR instructions and > checks some conditions. You can have your own implementation that, > instead of returning the first matching PHI, return all matching PHIs. > SimplifyIndVar won't try to canonicalize, though. > > Michael > ________________________...

...ief look at LLVM OPT (dev trunk). I would expect loop simplification and induction variable canonicalization pass (IndVarSimplify pass) should be able to convert the following loops into a simple canonical form, i.e., there is a canonical induction variable which starts at zero and steps by one, getCanonicalInductionVariable() returns the first PHI node in the loop header block. int test1 (int x[], int k, int s) { int sum = 0; for (int i = 0; i < k; i+=s) { sum += x[i]; } return sum; } int test2(int x[], int k, int s) { int sum = 0; for (int i = k; i > 0; i--) { sum += x[i]; } retur...

Hello, I need to perform the analysis of loop induction variables. However, as I understood, directly it is possible to extract only a canonical induction variable which is only one. If I have multiple induction variables with the step not one, are there any methods to extract their phi node? int a[10]; int b[10]; for (int i = 0, j = 1; i < 10, j < 10; i++, j+=2) {

Hi, How does LLVM identify induction variables of a loop? Is the algorithm based on SSA graphs? I have a complicated loop and I need to do some analysis around it. Can anyone please point me to source of identification part? -- *Disclaimer: Views, concerns, thoughts, questions, ideas expressed in this mail are of my own and my employer has no take in it. * Thank You. Madhur D. Amilkanthwar

On May 5, 2011, at 5:11 AM, Rotem, Nadav wrote: > Malveeka, > > You can use the LoopInfo analysis to find the induction variable. > > http://llvm.org/docs/doxygen/html/classllvm_1_1Loop.html#a72bbf45d2e00971f56bf8cfe4e1df01c > > Cheers, > Nadav getCanonicalInductionVariable is a good example of finding IVs without iterating over instructions. But you may need to generalize it a bit for your purpose. A completely general approach to IV analysis is ScalarEvolution. You can query the expression for a loop header phi using ScalarEvolution::getSCEV. If it returns SCEV...

...proper loop structures; instead it relied on labels and goto statements. Therefore, I am trying to find a way to identify the loop structure and print it out in the backend. So far, the main issue I’ve been having trouble with is identifying the loop induction variable in a straight forward manner; getCanonicalInductionVariable doesn’t always succeed, and I’ve tried using InductionDescriptor, but it fails in cases where the CFG doesn’t include a loop preheader. Also, in both cases, I couldn’t find a direct way of determining the loop exit condition. I am wondering if there are any passes or data structures that would...

...{ > std::cerr << "Block Before: " << *GEPI->getParent(); > Instruction *mul = BinaryOperator::createMul(saved_trip_count, > LI->getLoopFor( phi->getIncomingBlock(1) ) > ->getCanonicalInductionVariable(), "mul.", GEPI); > Instruction *add = BinaryOperator::createAdd(mul, NewAdd, "add.", GEPI); > GEPI->setOperand( 0, phi->getIncomingValue(0) ); > GEPI->setOperand( 1, add ); > std::cerr...

..."\n" ; errs() << "Is simplifyed loop?\t" << l->isLoopSimplifyForm() << "\n" ; errs() << "Tripcount " << l->getSmallConstantTripCount() << "\n" ; const PHINode* phi = l->getCanonicalInductionVariable(); errs() << "Induction variable: " << *phi << "\n"; } } } When I feed it with this program: int main(int argc, char** argv) { int i = 0; for (; i < 4; i++) { int j = 0; for (; j < 8; j++) {...

Hello . I ran opt with -indvars options , got wrong result.  This is my example: test.cc :  int test(int a)                 {      for (int i = 2; i < a; ++i) {                            a += ;      }              return a; } clang -O3 -emit-llvm -S test.cc -o test.ll opt -indvards -S test.ll  -o indvars.ll > /dev/null indvars.ll : ; ModuleID = 'test.ll' target datalayout =

...expect loop simplification and induction > > variable canonicalization pass (IndVarSimplify pass) should be able to > > convert the following loops into a simple canonical form, i.e., there is > a > > canonical induction variable which starts at zero and steps by one, > > getCanonicalInductionVariable() returns the first PHI node in the loop > > header block. > > > > int test1 (int x[], int k, int s) { > > int sum = 0; > > for (int i = 0; i < k; i+=s) { > > sum += x[i]; > > } > > return sum; > > } > > s could be zero...

Malveeka, You can use the LoopInfo analysis to find the induction variable. http://llvm.org/docs/doxygen/html/classllvm_1_1Loop.html#a72bbf45d2e00971f56bf8cfe4e1df01c Cheers, Nadav From: llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-bounces at cs.uiuc.edu] On Behalf Of Malveeka Tewari Sent: Thursday, May 05, 2011 14:51 To: llvmdev at cs.uiuc.edu Subject: [LLVMdev] Loop transformations

Hello . I'm trying to implement FunctionPass for detecting loops in llvm IR. How can I get <condition> for loop from llvm::Loop object.? Is there any example? Thanks in advance, Edvard  -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20120723/85e7f2f9/attachment.html>

Hi I am trying to write up a transformation for the following code where instead of incrementing the loop variable by 1, I increment it by 2 ie. for (i=0; i < THRES; *i++*) { //do something } gets transformed to for (i=0; i < THRES; *i+=2*) { //do something } I am thinking of transforming the llvm bit-code in the following way. Iterate over the function for the original code till I

...<< "Block Before: " << *GEPI->getParent(); >> Instruction *mul = > BinaryOperator::createMul(saved_trip_count, >> LI->getLoopFor( phi->getIncomingBlock(1) ) >> ->getCanonicalInductionVariable(), "mul.", > GEPI); >> Instruction *add = BinaryOperator::createAdd(mul, > NewAdd, "add.", GEPI); >> GEPI->setOperand( 0, phi->getIncomingValue(0) ); >> GEPI->setOperand( 1,...