jump table x constant pool

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1

I had some problems adding the address of a jump table to the constant
pool. The problem is that the address of a jump table is not a
GlobalValue.Currently I decided to expand BRIND so that I can work on
simpler problems :slight_smile:

A small brain dump on the issue:
GlobalValues are currently used to represent functions and global
variables. Maybe we could also use then for anything that will have a
label in the final assembly: functions, global variables, basic
blocks, jump tables and constant pools.

If we do so it would be very easy to add a jump table to a constant
pool (analogous to adding a global variable). It would also be
possible to add basic blocks, so maybe we could merge jump tables and
constant pools in one class?

Best Regards,
Rafael

2

Sounds like you need to define a machine specific constantpool value. Take a look at MachineConstantPoolValue in llvm/CodeGen/MachineConstantPool.h

e.g.

class ARMConstantPoolValue : public MachineConstantPoolValue {
   unsigned JTIndex;
   GlobalValue *GV;
...
};

Then in your lowering routine you can do DAG.getTargetConstantPool(new ARMConstantPoolValue, MVT::i32, alignment)

Make sure you define getExistingMachineCPValue() and AddSelectionDAGCSEId() correctly. The former is called by getConstantPoolIndex() to look for a duplicate entry in the constant pool. The later is used by SelectionDAG::getConstantPool().

Evan