Hello, 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. Thank you, Babak
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 -- http://nondot.org/sabre/ http://llvm.org/
On Jun 8, 2007, at 10:05 AM, Chris Lattner wrote:> 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 >Well, what I am looking for is the size of data that an instruction operates on. For example, if there is a mov instruction I need to know whether it is movb or movl or any other variant. -Babak