[LLVMdev] How to get the left-hand operand of an instruction?

increaseing qqsmallpig at gmail.com
Tue Apr 6 04:37:53 PDT 2010


Hi  Duncan,

I have catched your reply and solved the problem. Thank you for the
elaborate reply.


Best Regards!



2010/4/6 Duncan Sands <baldrick at free.fr>

> Hi increaseing, please ask on the list rather than writing to me directly.
> That way others can answer, and the discussion is archived for the benefit
> of people with the same question in the future.
>
> Best wishes,
>
> Duncan.
>
>  I have another question:
>> If I want to catch the point pointing to an allocated regin using malloc
>> and its length(for example, x.p and n in the next statement), what
>> should I do?
>> x.p = malloc(n);
>> Thank you very much!
>> Best Regards!
>>
>>
>> 2010/4/6 Duncan Sands <baldrick at free.fr <mailto:baldrick at free.fr>>
>>
>>
>>    Hi Qiuping yi,
>>
>>     > I am a new novice of LLVM, and I want know how to get the left-hand
>>     > operand of an instruction?
>>     >
>>     > For example:
>>     > how to get the %temp2 operand in the next instruction:
>>     >
>>     > %temp2 = malloc i8, i32 %n
>>
>>    there is no left-hand side, temp2 is just a name for the instruction.
>>    Since the LLVM IR is in SSA form, registers have exactly one
>> definition,
>>    and thus there is no point in distinguishing between a register and the
>>    instruction that defines it.  In short, whenever you would like to make
>>    use of "%temp2", just use the instruction ("malloc i8, i32 %n")
>>    directly.
>>
>>    Ciao,
>>
>>    Duncan.
>>    _______________________________________________
>>    LLVM Developers mailing list
>>    LLVMdev at cs.uiuc.edu <mailto:LLVMdev at cs.uiuc.edu>
>>    http://llvm.cs.uiuc.edu <http://llvm.cs.uiuc.edu/>
>>
>>    http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>>
>>
>>
>
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