log
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add_idle_callback x7ffb339f8040 , x0   <==== here in perl  the pointer to function is 64bits
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<=========== but then swig- SvUV() or SvIV() cast it to 32 bits
:: x339f8040 to x339f8040  
::DPTR2FPTR x339f8040 to x339f8040 
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