C undefined behavior fix
Quoted 9 lines
From: [email protected]
To: [email protected], [email protected], [email protected]
Date: Sun, 6 Jan 2002 14:32:01 -0500 (EST)Ah ha! But then look again at my 16-bit example, an expert assembly langauge programmer will use a 32 bit load if efficiency is not an issue (and it does not matter if there are extra bits around), but a 16-bit load if the hardware for some reason requires it. How is the poort C compiler to distinguish these cases automatically?
When you give the compiler as much information to it as your expert apparently has, then it will produce the same code, until then, imagine you told you expert that you want to do a 16 bit fetch for something that might care if it were not a 16 bit access... If you so tie your experts hands, as you tie gcc hands, then should produce similar code.
Now, if you want to invent gcc extensions so that it can know as much as a domain expert, start proposing those language extensions...