RE: [PATCH] MIPS: Correctly update the isa and arch_test_option_p variables after the arch dependency handling code in mips.exp

["Moore, Catherine" <Catherine_Moore@mentor.com>]

> -----Original Message-----
> From: Andrew Bennett [mailto:Andrew.Bennett@imgtec.com]
> Sent: Tuesday, July 14, 2015 9:24 AM
> To: Richard Sandiford; Matthew Fortune
> Cc: gcc-patches@gcc.gnu.org; Moore, Catherine
> Subject: RE: [PATCH] MIPS: Correctly update the isa and arch_test_option_p
> variables after the arch dependency handling code in mips.exp
> 
> > Yeah, I agree that this doesn't really fit the model that well, but
> > like you say, we're stretching the logic a bit :-).  When I wrote it,
> > the architectures formed a nice tree in which moving to leaf nodes
> > only added features.  So in the pre-r6 days:
> >
> >     # Handle dependencies between the pre-arch options and the arch
> option.
> >     # This should mirror the arch and post-arch code below.
> >     if { !$arch_test_option_p } {
> >
> > increased the architecture from the --target_board default to match
> > the features required by the test, whereas:
> >
> >     # Handle dependencies between the arch option and the post-arch
> options.
> >     # This should mirror the arch and pre-arch code above.
> >     if { $arch_test_option_p } {
> >
> > turned off features from the --target_board default to match a lower
> > architecture required by the test.  So in the pre-r6 days, all the
> > code in the second block was turning something off when going to a
> > lower architecture.  The blocks were mutually-exclusive and writing it
> > this way reduced the number of redundant options.  (Admittedly you
> > could argue that it's daft to worry about that given the kind of
> > command lines you tend to get from the rest of mips.exp. :-))
> >
> > r6 is the first time we've had to turn something off when moving up.
> > -mnan and -mabs are also the first options where old architectures
> > support only A, higher revisions support A and B, and the newest
> > revision supports only B.  I think I'd prefer to acknowledge that and
> > have:
> >
> >     # Handle dependencies between the arch option and the post-arch
> options.
> >     # This should mirror the arch and pre-arch code above.  For pre-r6
> >     # architectures this only needs to be done when we've moved down
> >     # to a lower architecture and might need to turn features off,
> >     # but moving up from pre-r6 to r6 can remove features too.
> >     if { $arch_test_option_p || ($orig_isa_rev < 6 && $isa_rev >= 6) }
> > {
> >
> > I think the existing r6->r5 case really is different: there we're
> > forcing a -mnan option not because the architecture needs it but
> > because the environment might.
> 
> Hi,
> 
> An updated patch and ChangeLog which reflects the comments is below.
> I have tested it on the mips-img-elf and mips-mti-elf toolchains with all the
> valid multilib configurations and there are no new regressions.
> 
> Ok to commit?

Yes, this is OK.
> 
> 
> testsuite/
> 	* gcc.target/mips/mips.exp (mips-dg-options): Allow the post-arch
> 	code to be run when the pre-arch code increases the isa_rev to
> 	mips32r6 or greater.
> 
>