On Mon, Jan 24, 2022 at 11:41 AM Jakub Jelinek <ja...@redhat.com> wrote: > > On Mon, Jan 24, 2022 at 11:17:00AM +0100, Richard Biener wrote: > > > I think with the 2) patch I achieve what we want for Fortran, for 1) > > > the only behavior from gcc 11 is that > > > -fsanitize-coverage=trace-cmp,trace-cmp is now rejected. > > > > But -fsanitize-coverage=trace-cmp -fsanitize-coverage=trace-cmp is not? > > With the incremental patch, the -fsanitize-coverage behavior is simply > that trace-pc is 1 and trace-cmp is 2 (both are required to be pow2p) > and any time trace-cmp appears in the -fsanitize-coverage=, it does |= 2, > any time trace-pc appears there it does |= 1, for -fno-sanitize-coverage= > any times trace-cmp appears it does &= ~2 and trace-pc &= ~1. > > > What's the semantics of -fconvert=big-endian > > -fconvert=little-endian,r16_ieeee? > > Does the latter replace big-endian with little-endian but add r16_ieeee? > > Yes. big-endian and little-endian is mutually exclusive, so a latter > occurrence of one of those overrides the former. big-endian and r16_ieee > aren't mutually exclusive, different Set, so it is set next to it. > Similarly for > -fconvert=big-endian,r16_ibm -fconvert=little-endian,r16_ieee > the end effect for both is the same as just > -fconvert=little-endian,r16_ieee > But e.g. > -fconvert=big-endian -fconvert=r16_ibm > the effect is -fconvert=big-endian,r16_ibm > > > I suppose we could interpret -fFOO=BAR,BAZ as -fFOO=BAR -fFOO=BAZ > > thus process items left-to-right? It's at least odd if > > They behave very similarly, the only difference is that in the -fFOO=BAR,BAZ > syntax we error on mutually exclusive options. My rationale is, the > overriding through -fFOO=BAR -fFOO=BAZ if BAR and BAZ are mutually exclusive > is desirable, the two options could come from different make etc. variables > or compiler wrapper scripts or -specs etc. But when it is a single option, > that option comes from a single source only and users should be told they > are doing something weird like -fconvert=little-endian,big-endian,swap > The compiler should hint them that they likely don't know what they want.
OK, that sounds reasonable. With the same reasoning -fconvert=swap,swap might be a typo and is reasonable to diagnose (but less important so I guess). Richard. > Jakub >
