IIROperand AllocateOperand(IIROperand operand, RegisterPool pool)
{
if (operand is IRVariable)
{
var variable = (IRVariable)operand;
StackSlot?slot;
var reg = AllocateVariable(pool, variable, out slot);
if (reg != null)
{
return new IRRegister(reg.Value)
{
SourceVariable = variable,
Type = variable.Type
}
}
;
variable.Annotation = slot.Value;
return(new IRPointer {
Register = IRRegister.BP,
Offset = slot.Value.Offset,
SourceVariable = variable,
Type = variable.Type
});
}
return(operand);
}
VMRegisters?AllocateVariable(RegisterPool pool, IRVariable var, out StackSlot?stackSlot)
{
stackSlot = pool.CheckSpill(var);
if (stackSlot == null)
{
var allocReg = var.Annotation == null ? (VMRegisters?)null : (VMRegisters)var.Annotation;
if (allocReg == null)
{
allocReg = pool.Allocate(var);
}
if (allocReg != null)
{
if (var.Annotation == null)
{
var.Annotation = allocReg.Value;
}
return(allocReg);
}
// Spill variable
stackSlot = pool.SpillVariable(var);
}
return(null);
}
}
private VMRegisters?AllocateVariable(RegisterPool pool, IRVariable var, out StackSlot?stackSlot)
{
stackSlot = pool.CheckSpill(var);
if (stackSlot == null)
{
var allocReg = var.Annotation == null ? (VMRegisters?)null : (VMRegisters)var.Annotation;
if (allocReg == null)
{
allocReg = pool.Allocate(var);
}
if (allocReg != null)
{
if (var.Annotation == null)
{
var.Annotation = allocReg.Value;
}
return(allocReg);
}
// Spill variable
stackSlot = pool.SpillVariable(var);
}
return(null);
}