phillip j eby moetelecommunitycom 1043 pm 3222008 0000 antoine pitrou wrote relative absolute jump instructions traditional rationale relative jumps apart positionindependent code allow shorter operand sizes python opcodes operand size actually dont 32bit arguments extended_arg opcode extended_arg loads high 16 bits argument opcode immediately follows 16 bits enough address bytecode arrays ah bytecode arrays apparently automatically generated code lucasfilm memory serves exceeded 16bit limits bytecode extended_arg opcode added fix relative jumps unsigned means jump forward soon want jump backward switch absolute jump backward jump already know exact offset know need 16bit 32bit operand regard dont understand jump_forward possibly bring jump_absolute means dont guess whether jump target going cross 64k boundary thereby requiring used 32bit operand course limit forward jumping skipping 64k block apparently nobody exceeded limit yet merely 64k total bytecode presumably easier limit reach jumping 64k worth bytecode truth dont know thats really reason things originally set way certainly among reasons thing probably stay way _______________________________________________ pythondev mailing list zvlllneumpythonorg httpmailpythonorgmailmanlistinfopythondev unsubscribe httpmailpythonorgmailmanoptionspythondevpythondev40tangomucom wed 06 aug 2008 164612 0400 pythondev two questions jump opcodes