similar to: [LLVMdev] Dereferencing null pointers

Sorry for the confusion, I pasted the code I fixed locally... Here is the code at top of the trunk: // load (select (cond, null, P)) -> load P if (Constant *C = dyn_cast<Constant>(SI->getOperand(1))) if (C->isNullValue()) { LI.setOperand(0, SI->getOperand(2)); return &LI; } So it is a bug? -----Original Message----- From:

Hi. This is part of my code: ... if (auto* op = dyn_cast<BinaryOperator>(&I)) { Value* lhs = op->getOperand(0); Value* rhs = op->getOperand(1); Value* mul = builder.CreateMul(lhs, rhs); for (auto& U : op->uses()) { User* user = U.getUser(); user->setOperand(U.getOperandNo(), mul); } I.eraseFromParent(); } ... This leads to the following

> On Dec 8, 2014, at 5:12 PM, Sanjoy Das <sanjoy at playingwithpointers.com> wrote: > > Partially answering my own question, in general these are not > equivalent because LLVM allows for pointers in different address > spaces to have different sizes. However, are they equivalent if > pointers in addrspace(1) have the same size as pointers in > addrspace(0)? > >

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 =

Is copy.0 semantically equivalent to copy.1 in the following example? define void @copy.0(i8 addrspace(1)* addrspace(1)* %src, i8 addrspace(1)* addrspace(1)* %dst) { entry: %val = load i8 addrspace(1)* addrspace(1)* %src store i8 addrspace(1)* %val, i8 addrspace(1)* addrspace(1)* %dst ret void } define void @copy.1(i8 addrspace(1)* addrspace(1)* %src, i8 addrspace(1)* addrspace(1)* %dst)

I am able to access the source operands of an instruction using either getOperand() or op_iterator, However, I can't find any method available for destination operand. Someone suggests that instruction itself can represent the destination operand. http://lists.cs.uiuc.edu/pipermail/llvmdev/2011-January/037518.html The getOperand() returns an unsigned value like 0x9063498, while I can't

I recently began hacking around with my first LLVM pass. The big picture is that I would like to insert function calls for each instruction type, and pass some parameters based on the instruction type. Then I will link the output to some C file that implements those functions. Things were going well until I started trying to make function calls with a pointer as a parameter. For example, I would

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>

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

Hello, I need to append something to the global "llvm.global_ctors". This variable may or may not already be declared within the current module. If I lookup the global variable, I see that it supports a getOperand(i) and setOperand(i,c), but does not support any way that I can enlarge that array to add a new record. Any suggestions? -- Nick Johnson

Hello, I am trying to reset the operands of instructions. What I am doing is, I am finding all Uses of a specific operand in an Instruction and resetting it with a new value using "setOperands(int, Value*)". I am doing as: for (auto vmitr=vm.begin(), vsitr=vs.begin(); vmitr!=vm.end() && vsitr!=vs.end(); vmitr++, vsitr++){ // I have two *Value ( operands) for ( auto myitr

Hi John, It seems the dereferencing a NULL pointer is undefined behavior but Calling a function through a null pointer seems o.k. If so , for this place, we need comment out the check. http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#232 look at Notes from the October 2003 meeting. Yin From: John Criswell [mailto:criswell at illinois.edu] Sent: Wednesday,

Launcher <st.liucheng at gmail.com> writes: > I am able to access the source operands of an instruction using either > getOperand() or op_iterator, However, I can't find any method available for > destination operand. Someone suggests that instruction itself can represent > the destination operand. > http://lists.cs.uiuc.edu/pipermail/llvmdev/2011-January/037518.html

Hi all, I am almost ready for the last step with landing my long-standing patch. I have converted (almost) all low-level interface users of CallInst to respective high-level interfaces. What remains is a handful of hunks to flip the switch. But before I do the final commit I'd like to coerce all external users to code against the high-level interface too. This will (almost, but see below)

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++

What LoopVectorize.cpp has are the following. Each function may have to have a separate consolidation discussion. I'm bringing up getpointerOperand() since I actually found multiple instances defined/used. DependenceAnalysis.cpp has isLoadOrStore(). LoopAccessAnalysis.cpp has getAddressSpaceOperand(). I'm sure there are others that might be worth discussing within this thread or a follow

Dan Gohman wrote: > Hello, > > On Nov 4, 2009, at 1:51 AM, Hans Wennborg wrote: >> >> / Hans >> Index: lib/Analysis/BasicAliasAnalysis.cpp >> =================================================================== >> --- lib/Analysis/BasicAliasAnalysis.cpp (revision 86023) >> +++ lib/Analysis/BasicAliasAnalysis.cpp (working copy) >> @@ -633,6 +633,15

"Saito, Hideki via llvm-dev" <llvm-dev at lists.llvm.org> writes: > LLVM friends, > > I'm currently trying to make LoopVectorizationLegality class in > Transform/Vectorize/LoopVectorize.cpp more modular and eventually move > it to Analysis directory tree. It uses several file scope helper > functions that do not really belong to LoopVectorize. Let me start

Hi, For a small case, that calls NULL pointer function. LLVM explicitly converts It to a store because it thinks it is not reachable like calling undefvalue. In InstCombineCalls.cpp:930 I think it is not a right approach because calling null pointer function Will segfault the program. Converting to a store will make program pass Silently. This changes the behavior of a program.