[LLVMdev] Requiring LiveIntervals
sabre at nondot.org
Tue Sep 20 07:56:58 PDT 2005
On Tue, 20 Sep 2005, Tzu-Chien Chiu wrote:
> One of my pass requires LiveIntervals to build the interference graph,
> because LiveVariables do not provide an interface to iterate through
> all viritual registers.
Ok, you could add a method to LiveVariables that returns
VirtRegInfo.size(). The virtual registers are defined by the range:
Alternatively, the same information can be obtained from the SSARegMap for
the function: given a MachineFunction, use something like:
NumVRegs = MF.getSSARegMap()->getLastVirtReg()+1;
These also start from MRegisterInfo::FirstVirtualRegister.
> But LiveIntervalAnalysis.h is not in
> "include/llvm/CodeGen", so I have to either include it by:
> #include "../../llvm/lib/CodeGen/LiveIntervalAnalysis.h"
> or point my project include path to "llvm/lib/CodeGen" (I use Visual Studio).
> Why LiveIntervalAnalysis.h is not in "include/llvm/CodeGen" ?
It was intended to be used as an internal interface, but if you really
would like it, I would have no problem promoting it to be a public
interface. Let me know what you'd like.
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