[LLVMdev] Operand, instruction

help__me_please krishnadhan at cse.iitb.ac.in
Thu Apr 22 06:37:57 PDT 2010

Hello, how to get the numerical value of an constant operand? For ex. %tmp =
mul i32 %indvar, 6 , in this instruction second operand is a numerical
constant with value 6. But i am only able to print it by using
getOperand(1), not able to store it in any integer variable. Using getName()
returns a empty string. Is there any way to solve this problem?
Thank you. 

John Criswell-2 wrote:
> help__me_please wrote:
>> Can you please give an example of creating an instruction (for example
>> add
>> instructions with two operand a and b)? I am trying instruction() for a
>> while, but no success yet.
> You need to look for the appropriate subclass of llvm::Instruction and 
> find the method for creating a new instruction.  The method is usually a 
> static method and takes arguments pointing to the values to use as 
> operands.  Doxygen is your best resource for finding these methods.
> For example, if you look at 
> http://llvm.org/doxygen/classllvm_1_1AllocaInst.html, you can see that 
> the AllocaInst class (which represents an alloca instruction) has a 
> standard constructor method that takes the type of object to allocate, 
> the name of the new alloca instruction, an instruction before which to 
> insert the alloca instruction, etc.
> As another example, the CallInst class 
> (http://llvm.org/doxygen/classllvm_1_1CallInst.html) represents a call 
> instruction and has a static Create() method that you can use to create 
> a new call instruction.
> -- John T.
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev

View this message in context: http://old.nabble.com/Operand%2C-instruction-tp21961718p28329007.html
Sent from the LLVM - Dev mailing list archive at Nabble.com.

More information about the llvm-dev mailing list