similar to: [LLVMdev] def-use chains and use-def chains

Hi Duncan Sands, I frankly don't know what a variable gets converted to (SSA register or memory chunk). What I meant is, for example I1: int i, j=10; I2: scanf("%d", &j); I3: i = j + 1; Here I want to know whether the value of j in I1 reaches I3 or not. Best Regards, Srikanth Vaindam you didn't define what you mean by a variable. LLVM has virtual registers which are

On 5/3/11 4:08 PM, tarun agrawal wrote: > HI > > I know it is a very simple question not worth asking here but I am > really struggling pls help me out.. This is a question worth asking; it's just that not everyone can answer all the time. :) If all you want to do is to follow the SSA def-use chain within a single function, then this is very easy. All you have to do is use

Thanks John, I know how to iterate through def-use chains and I also have realized the need for an algorithm to do the work. But the algorithm I am able to figure out is not linear in time. It wold be a great help if someone suggest me a way to get all basic-block along all path between two instruction. On Wed, May 4, 2011 at 7:00 AM, John Criswell <criswell at illinois.edu> wrote: >

Dear Tarun, It just occurred to me that this may or may not be what you are asking about. This only finds basic blocks along the def-use chain of an instruction; it does not find all basic blocks along all paths between two instructions. I don't know of an algorithm off-hand for the latter, but if you understand how to iterate over def-use chains and the control-flow graph, then

HI I know it is a very simple question not worth asking here but I am really struggling pls help me out.. On Tue, May 3, 2011 at 10:10 PM, tarun agrawal <tarun at cse.iitb.ac.in> wrote: > Hi, > > I need to get all the basic blocks that are there, in the path from > definition of an instruction to use of that instruction. > > > Regards > Tarun > --------------

Hi, I need to get all the basic blocks that are there, in the path from definition of an instruction to use of that instruction. Regards Tarun -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20110503/4d3852b7/attachment.html>

On Jan 11, 2008, at 2:00 PM, David Greene wrote: > Is there any way to discover whether a particular operand of a > MachineInst > participates in addressing? That is, if the MachineInst references > memory, > can I tell, given an operand, whether that operand is part of the > address > calculation for the instruction? Nope, not that I know of. > Also, is there any

On Friday 11 January 2008 16:36, Chris Lattner wrote: > On Jan 11, 2008, at 2:00 PM, David Greene wrote: > > Is there any way to discover whether a particular operand of a > > MachineInst > > participates in addressing? That is, if the MachineInst references > > memory, > > can I tell, given an operand, whether that operand is part of the > > address >

Hello All, What would be the best way to trace Value Dependency Chains in LLVM. Can I use some API to perform this? The use-def chain process mentioned at http://llvm.org/docs/ProgrammersManual.html#iterate_chains will just get the values (Operands) being used in the current Instruction. For getting the values operands in the particular instruction are influenced from I have to recursively call

Is there any way to discover whether a particular operand of a MachineInst participates in addressing? That is, if the MachineInst references memory, can I tell, given an operand, whether that operand is part of the address calculation for the instruction? Also, is there any reasonable way to get the set of machine instructions to which the output(s) of some machine instruction flows? The

Programmers’ manual says we can iterate over a use-def chain by op_iterator. It works fine except for load and store instruction of stack variables. For example, a simple bitcode is like the below. i = alloca i32 store i32 0, i32* %i, align 4 %tmp1 = load i32* %i, align 4 If I apply a use-def chain to load instruction, I get alloca instruction. I think store instruction is a correct

Hello all, I am a LLVM newer who want to obtain the use-def chain for all instruction of a sample code, for this purpose i use the following code. ///////////////sample code:///////////////////////// #include <stdlib.h> #include <stdio.h> #include <time.h> #define ARRAY_SIZE 5 int main() { int x, y, holder; int k,z,f,i; z=0; f=0; k=0; for(x = 0; x < ARRAY_SIZE;

It would be great help if someone can point me to similar code in Analysis or Transform, i.e. tracing value dependencies chains. Thanks, Manish On Wed, Aug 3, 2011 at 10:47 AM, Manish Gupta <manishg at cs.ucsd.edu> wrote: > Hello All, > > What would be the best way to trace Value Dependency Chains in LLVM. Can I > use some API to perform this? > > The use-def chain

On 8/4/11 1:53 PM, Manish Gupta wrote: > It would be great help if someone can point me to similar code in > Analysis or Transform, i.e. tracing value dependencies chains. If I understand correctly, given an instruction I, you want to find its operands o1 through oN, and then find the instructions (or LLVM values) that generate the values o1 through oN, and then find the instructions

Hello All, Is the use-define chain related API avaliable in LLVM? I want to get the information about the variables' value changes at different points in the program. Best wishes.

Hey John, Yes this is what I am looking for. I wrote a code as I described in my first mail and I am getting desired result except when the chain encounters load instruction (you have also mentioned the that u skip loads). I think the recursive trace back for a Value V depending on Operands (o1,...oN) should terminate at the nearest definition of the oN (i.e. it is not an instruction but a LLVM

Thanks for your response! But I want to determine wheter the specific variable's value has been changed between two usages of variable, and wheter the parameter's value is changed in a function. Like the reaching definition analysis, and ud chains. 2012/8/9 ��f�� (Wei-Ren Chen) <chenwj at iis.sinica.edu.tw>: > On Thu, Aug 09, 2012 at 11:16:15AM +0800, Jianfei Hu wrote: >>

Thanks Quentin. I'm trying to examine from the operands of the return instruction, and then to get the last assignment of those. I thought use_iterator/reg_iterator may suit better than just loop through the machine basicblock in the reverse order. Cheng-Chih On Thu, Sep 25, 2014 at 1:51 PM, Quentin Colombet <qcolombet at apple.com> wrote: > Hi Cheng-Chih, > > On Sep 25,

On 8/4/11 2:45 PM, Manish Gupta wrote: > Hey John, > > Yes this is what I am looking for. I wrote a code as I described in my > first mail and I am getting desired result except when the chain > encounters load instruction (you have also mentioned the that u skip > loads). Okay. Just out of curiosity, is your static slice local (stopping at function arguments) or

On Thu, Aug 09, 2012 at 11:16:15AM +0800, Jianfei Hu wrote: > Hello All, > > Is the use-define chain related API avaliable in LLVM? I want > to get the information > about the variables' value changes at different points in the program. Is this [1] fit your need? HTH, chenwj [1] http://llvm.org/docs/ProgrammersManual.html#iterate_chains -- Wei-Ren Chen (陳韋任)