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

Duncan Sands baldrick at free.fr
Tue Apr 6 02:03:54 PDT 2010


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.



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