llvm dev - Feb 2009 - [LLVMdev] Operand, instruction

Hi,
How can one extract the operand of an instruction in an LLVM pass?
Like I can get the opcode bt I'd like to get the operands as well

Thanks
Nipun
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On Feb 11, 2009, at 10:42 AM, Nipun Arora wrote:
> Hi,
>
> How can one extract the operand of an instruction in an LLVM pass?
> Like I can get the opcode bt I'd like to get the operands as well
>
getOperand(i).  See Instruction.h and User.h

-
Devang

Nipun Arora wrote:
> Hi,
>
> How can one extract the operand of an instruction in an LLVM pass?
> Like I can get the opcode bt I'd like to get the operands as well
>   
Use the getOperand() method of class Instruction (which I think is
inherited from Value or User or some other LLVM class).  It takes a
single parameter that is an index specifying which operand to return. 
The return value is a llvm::Value *, IIRC.

If you haven't used it yet, I'd recommend using the LLVM doxygen
documentation (http://llvm.org/doxygen/hierarchy.html).  I've found it
to be an invaluable resource for answering these sorts of questions.  In
this case, just look up the llvm::Instruction class and see if it has a
method that does what you want.  If it doesn't, check its parent class,
the grandparent class, etc. until you find the method you want.

-- John T.
> Thanks
> Nipun
>
>

Can anyone tell how to get the result name or instruction name of all
instruction? For example if the instruction is "x=add y,z", here i
need "x".
Using getName(), i am getting some instructions result name, but llvm
produces some instruction like "%0=add i32 tmp, 1", here getName()
shows
empty string as result name. 
So please help.

John Criswell wrote:
> 
> Nipun Arora wrote:
>> Hi,
>>
>> How can one extract the operand of an instruction in an LLVM pass?
>> Like I can get the opcode bt I'd like to get the operands as well
>>   
> Use the getOperand() method of class Instruction (which I think is
> inherited from Value or User or some other LLVM class).  It takes a
> single parameter that is an index specifying which operand to return. 
> The return value is a llvm::Value *, IIRC.
> 
> If you haven't used it yet, I'd recommend using the LLVM doxygen
> documentation (http://llvm.org/doxygen/hierarchy.html).  I've found it
> to be an invaluable resource for answering these sorts of questions.  In
> this case, just look up the llvm::Instruction class and see if it has a
> method that does what you want.  If it doesn't, check its parent class,
> the grandparent class, etc. until you find the method you want.
> 
> -- John T.
> 
>> Thanks
>> Nipun
>>
>>   
> 
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> 
> 
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