On Mon, Mar 30, 2020 at 05:51:49PM -0500, Segher Boessenkool wrote: > Hi! > > On Mon, Mar 30, 2020 at 12:50:43PM -0500, will schmidt wrote: > > On Fri, 2020-03-27 at 21:31 -0400, Michael Meissner via Gcc-patches > > > * config/rs6000/rs6000.c (PCREL_SUPPORTED_BY_OS): New macro. > > > (rs6000_option_override_internal): Set the -mprefixed and > > > -mpcrel > > > options for -mcpu=future if these options can be used. > > > > > s/can be used/are supported by the platform/ ? > > The code says > /* Enable -mprefixed by default on 64-bit 'future' systems. */ > /* If the OS has support for PC-relative relocations, enable it now. */ > and something like that should go in the changelog as well (two lines in > changelog is fine -- they are two hunks of patch as well, anyway!)
Ok. > > > +/* Enable default support for PC-relative addressing on the 'future' > > > system if > > > + we can use the PC-relative instructions. Currently this support > > > only exits > > > > exists > > > > > + for the ELF v2 object file format using the medium code > > > model. */ > > > > should that be "s/object file format/ABI/" ? > > Yes. Ok. > > > -/* Support for a future processor's features. Do not enable -mpcrel > > > until it > > > - is fully functional. */ > > > +/* Support for a future processor's features. We do not set -mpcrel > > > or > > > + -mprefixed here. These bits are set in rs6000_option_override if > > > the system > > > + supports those options. */ > > > > I'm still not sure the comment here is actually necessary, there are > > many other places where we also do not set -mpcrel or -mprefixed. If > > history of the code here requires a hint to point at those options > > being set in rs6000_option_override, then it's fine. > > If you really need to say you do *not* do something, you should say why > not. Without that it only leaves more questions to the reader :-) > > Hopefully that then also explains why the reader should care about this. Given this comment is against Will's comment, and not the original code, is there anything I need to do to the code (other than the ChangeLog and adjusting object file format to ABI? -- Michael Meissner, IBM IBM, M/S 2506R, 550 King Street, Littleton, MA 01460-6245, USA email: meiss...@linux.ibm.com, phone: +1 (978) 899-4797
