private int getBitFieldAlignment(BitFieldDataType bitfieldDt) {

		if (!bitFieldPacking.useMSConvention() && packValue != CompositeInternal.DEFAULT_PACKING) {
			// GCC always uses 1 when packing regardless of pack value
			return 1;
		}

		return CompositeAlignmentHelper
				.getPackedAlignment(bitfieldDt.getBaseDataType().getAlignment(), packValue);
	}
Get structure length after all components have been added.
@return structure length
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/data/AlignedComponentPacker.java