On 02/09/2017 09:17 AM, Thomas Schaefer wrote: > >> On 02/09/2017 02:32 AM, Thomas Schaefer wrote: >>> Hi York, >>> >>> >>> >>> When compiling latest u-boot with gcc 6.3 compiler, I get several >>> 'unused-const-variable' warnings in options.c file of FSL DDR driver. >>> Affected variables are for (DIMM_SLOTS_PER_CTLR==2) configuration (e.g. >> dual_0S[4]) and warnings could be fixed with the patch applied. >>> >>> >>> >>> What do you think? >> >> Thomas, >> >> Thanks for bringing it to my attention. I understand GCC 6 may have more >> warnings. The proposed patch is OK in logic but it increases the size of code >> unnecessarily. Can you come up with a different fix? >> >> I can come back to check after I finish my work on hand. >> >> York > > Hi York, > > not sure if I understand this correctly, but why is code size increased when > these > variables are not defined? I think code size is decreased instead as these > variables > are no longer defined if not needed. > > I also don't see a way to achieve this in a different way as the variables > are defined > differently for DDR2, DDR3 and DDR4. > >
Wait a minute, did you generate the patch backward? Your patch shows removing "#if CONFIG_DIMM_SLOTS_PER_CTLR==2" which doesn't exist in current code. If the logic is reversed, then yes, you are reducing the size. Can GCC 6 optimize out the unused data? If yes, maybe we can use __maybe_unused to get rid of the warning? York _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
