pb@idca.tds.PHILIPS.nl (Peter Brouwer) (11/21/89)
When looking at disassembler output I notices that all jumps were long jumps. Looking at the assembler man page I saw that a -n flag was there to set a force of generating long jumps. So I concluded , it could generate output with short jumps. From an assembler manual from Interactive I found out that a .optim / .noopt directives exist. The as can handle these directives. My question is : How can cc generate such directives in the assembler output. I have looked int the cc sources but could not find a clue. I have the feeling that cc does not bother about this. Is this correct? and if so is there a rason for it. I cannot think of a reason to not use the directives ( default or only with -O might be a discussion ). The intel documentation on jumps does not give a difference in speed but I imagine reading a 32 displacement takes more bus time than a 8 bits relative displacement. The bus speed difference might be lost by the calculation of the new address. The program size will in my opinion always be an argument to use it. -- Peter Brouwer, # Philips Telecommunications and Data Systems, NET : pb@idca.tds.philips.nl # Department SSP-P9000 Building V2, UUCP : ....!mcvax!philapd!pb # P.O.Box 245, 7300AE Apeldoorn, The Netherlands. PHONE:ext [+31] [0]55 432523, # Never underestimate the power of human stupidity