[LLVMdev] Bitwidth of Machine Instructions

Chris Lattner sabre at nondot.org
Fri Jun 8 10:05:01 PDT 2007


On Fri, 8 Jun 2007, Babak Salamat wrote:
> I am wondering if there is any way to figure out bitwidth of Machine
> Instructions. I see that ValueType information is available for nodes
> of DAG, but I couldn't find similar info for Machine Instructions. I
> particularly need this information for x86 target.
> I appreciate your help and comments in this regard.

Do you mean the size of an instruction, or the size of an operand?  Given 
a virtual or physical register, you can find the register class, then get 
the MVT::ValueType that the regclass can hold.

-Chris

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