I use the following code to print the basicblocks in my LLVM module’s object ID. To my surprise, different basicblocks share the same object ID, how could that be possible?

I got

foo
Block ID: 140516957688448
Block ID: 140516957688544
Block ID: 140516957688448
Block ID: 140516957688544
Block ID: 140516957688448
Block ID: 140516957688544
printf
main
Block ID: 140516957688448

So, the function main’s basicblock and function foo’s first basicblock have the same ID. Also, some basicblocks in foo have the same ID too. Is it a bug in my program below?

from llvmlite import binding as llvm

# Initialize the LLVM system
llvm.initialize()
llvm.initialize_native_target()
llvm.initialize_native_asmprinter()
    
def find_basic_block_ids(ir):
    # Parse the LLVM IR
    llvm_module = llvm.parse_assembly(ir)
    llvm_module.verify()


    for function in llvm_module.functions:
        print (function.name)
        for block in function.blocks:   
            block_id = id(block)
            print(f"Block ID: {block_id}")


if __name__ == "__main__":
    with open("mycode.ll", "r") as f:
        llvm_ir = f.read()

    find_basic_block_ids(llvm_ir)