similar to: [LLVMdev] replacing a global variable by a constant

Hi Ralf, > I am trying to replace a global variable with a constant. You should be able to replace the initializer for the global with your constant, mark it as having internal linkage and then run some optimization pass over it to do the rest (not sure which one it was again, probably some constant propagation or global value optimization). That pass would then probably do some similar

Thanks a lot for your help Matthijs! :) basically this does the job quite nicely I think: 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(); } Cheers, Ralf Matthijs Kooijman wrote: > Hi Ralf, > > >> I

Hi, I'm trying to change all uses of a global variable so they'll use a different global variable. For instance, I have: @a = global [100 x [100 x i64]] zeroinitializer, align 16 @b = global [100 x [100 x i64]] zeroinitializer, align 16 And I want to change the use %arrayidx = getelementptr inbounds [100 x [100 x i64]]* @a, i32 0, i64 %3 to %arrayidx = getelementptr inbounds

On Sat, Aug 9, 2014 at 6:06 AM, Tim Northover <t.p.northover at gmail.com> wrote: > Hi Rob, > > On 9 August 2014 02:03, Rob Jansen <jansen at cs.umn.edu> wrote: > > Why is the first for loop not equivalent to the second? > > In the second loop, "*ui" is an llvm::Use object. It's owned by a > User, but isn't a subclass of one. To match the

Why is the first for loop not equivalent to the second? Thanks, Rob =========================== for (GlobalVariable **i = Globals.begin(), **e = Globals.end(); i != e; ++i) { GlobalVariable *GV = *i; Constant *GEP = ConstantExpr::getGetElementPtr(...); GV->replaceAllUsesWith(GEP); } =========================== for (GlobalVariable **i = Globals.begin(), **e = Globals.end(); i != e;

Hi, I've been struggling with constantexprs for a bit. I'm working on a pass that transforms global variables to local variables, and in particular the GetElementPtrConstantExpr is a bit troublesome. For my transformation to properly work, a global value should only be used by Instructions, not by ConstantExprs. I was thinking to add a ConstantExpr::replaceWithInstr() virtual method,

I'm now writing a pass and I wanna ask a question about how to duplicate the function and add duplicated arguments in llvm, for example: func(int a, char *b) -> func(int a, char *b, int a1, char *b1) I'm now stuck at using "getOrInsertFunction" and how to handle "getArgumentList", please share your opinion, thanks a lot! James

Hello everyone, is there any way to replace an instruction inside LLVM that is more elegant than creating a new one, replacing uses and deleting the old one if I only want to modify the type? It is generally not a big deal, but the issue gets really messy if I am in the middle of iterating over uses and start deleting some of them... I hope I could describe my problem well enough ;) Regards,

On Tue, Jun 17, 2008 at 8:50 AM, Matthijs Kooijman <matthijs at stdin.nl> wrote: > Hi, > > I've been struggling with constantexprs for a bit. I'm working on a pass that > transforms global variables to local variables, and in particular the > GetElementPtrConstantExpr is a bit troublesome. For my transformation to > properly work, a global value should only be used

Hi. Thanks. I changed the code but the problem exists. This is my new code which is again very simple: ... bool runOnFunction(Function &F) override { vector<Instruction *> dels; dels.clear(); for (inst_iterator It = inst_begin(&F), Ie = inst_end(&F); It != Ie;) { Instruction *I = &*(It++); if (auto* op = dyn_cast<BinaryOperator>(I)) { IRBuilder<NoFolder>

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.

LLVM is built in Release mode. The version is 6.0.0. I think that a similar code worked on verison 3.9.0. It is probably a null pointer dereference occurring in eraseFromParent(). I checked and reconfirmed that the instruction had no uses. Perhaps I should rebuild LLVM. Thanks. On Wed, Aug 8, 2018 at 9:03 PM, mayuyu.io <admin at mayuyu.io> wrote: > Hmmmm that’s strange. Do you get an

Thanks Bjorn! But The problem is still there. On Wed, Aug 8, 2018 at 2:04 AM, Björn Pettersson A < bjorn.a.pettersson at ericsson.com> wrote: > It looks quite dangerous to erase the instruction I inside the loop when > iterating over all instructions in the function. > I guess it depends on how the range based iterator is implemented if that > works or not. > > I think

On Apr 16, 2:13 am, Dan Gohman <goh... at apple.com> wrote: > Hi Gabor, > > Can you provide performance data for this? I'd > like to know what affect these changes have on > compile time. Hi Dan, Unfortunately, no. I can feed you with some speculation, though, see below. The reason why I cannot do measurements (at the moment) is that - I have no experience with

Albert Graef wrote: > The way I do this in Pure is to always call global functions in an > indirect fashion, using an internal global variable which holds the > current function pointer. When a function definition gets updated, the > Pure interpreter just jits the new function, changes the global variable > accordingly, and frees the old code. > > Compared to Duncan's

The code is really simple. But I can not the reason for the segmentation fault. I only know that the eraseFromParent() function leads to it. The whole code is: ... bool runOnFunction(Function &F) override { for (auto &I : instructions(F)) { if (auto* op = dyn_cast<BinaryOperator>(&I)) { IRBuilder<> builder(op); Value* lhs = op->getOperand(0); Value* rhs =

Hi Duncan, > I couldn't find the solution to my problem (if it has one) in the mailing >> list or the source code. The problem is: how can I redefine a function >> that's been called already by some other function? >> > > why do you want to do this? > To implement something that is common in Lisp. Suppose I have a program that is running and can't be

Ralf Karrenberg wrote: > Hello everyone, > > is there any way to replace an instruction inside LLVM that is more > elegant than creating a new one, replacing uses and deleting the old one > if I only want to modify the type? It is generally not a big deal, but > the issue gets really messy if I am in the middle of iterating over uses > and start deleting some of them... >

Hi everybody. I've just started learning about LLVM and didn't get too far studying the core. I couldn't find the solution to my problem (if it has one) in the mailing list or the source code. The problem is: how can I redefine a function that's been called already by some other function? Suppose I have 3 files, all compiled to bytecode through llvm-gcc (I think it could be clang

On Sat, Jan 30, 2010 at 6:22 PM, Conrado Miranda <miranda.conrado at gmail.com> wrote: > Albert Graef wrote: >> >> The way I do this in Pure is to always call global functions in an >> indirect fashion, using an internal global variable which holds the >> current function pointer. When a function definition gets updated, the >> Pure interpreter just jits the