On 05/30/2011 11:23 PM, Peter Hüwe wrote: > Hi Janitors, staging-list > > what is your opinion on using set_bit instead of using |= to set a bit? > Is it worth the effort to convert existing |= to set_bit? > > __set_bit > pro: > - often implemented in optimized assembly (e.g. for x86) > - intention might be clearer > - less error prone > - "they are the only portable way to set a specific bit" > according to Robert Love's Linux Kernel Development third edition, p.183 > > cons: > uses unsigned longs Note that you need to define a different set of macros. E.g. if you have for |=: #define FLAG1 0x01 #define FLAG2 0x02 #define FLAG3 0x40 for set_bit you need: #define FLAG1 0 #define FLAG2 1 #define FLAG3 6 Also with set_bit you can set only one bit at a time which might make the code longer and unreadable. For examples, see input layer. > |= > pro: > - standard C > - let's the compiler decide > - no warnings on chars, shorts, ints regards, -- js -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
