craig.topper added a comment. In D72906#1838532 <https://reviews.llvm.org/D72906#1838532>, @uweigand wrote:
> In D72906#1837905 <https://reviews.llvm.org/D72906#1837905>, @craig.topper > wrote: > > > In D72906#1826849 <https://reviews.llvm.org/D72906#1826849>, @uweigand > > wrote: > > > > > In D72906#1826122 <https://reviews.llvm.org/D72906#1826122>, > > > @craig.topper wrote: > > > > > > > In D72906#1826061 <https://reviews.llvm.org/D72906#1826061>, @uweigand > > > > wrote: > > > > > > > > > > The constrained fcmp intrinsics don't allow the TRUE/FALSE > > > > > > predicates. > > > > > > > > > > Hmm, maybe they should then? The only reason I didn't add them > > > > > initially was that I wasn't sure they were useful for anything; if > > > > > they are, it should be straightforward to add them back. > > > > > > > > > > > > What would we lower it to on a target that doesn’t support it natively? > > > > > > > > > Any supported compare (quiet or signaling as appropriate, just so we get > > > the correct exceptions), and then ignore the result (and use true/false > > > constant result instead)? > > > > > > Sure. Is that something we want to force all targets to have to implement > > just to handle this case for X86? Unless we can come up with a generic DAG > > combine to pick a valid condition alternate so that the lowering code for > > each target doesn't have to deal with it. > > > Hmm, OK. Given that this X86-specific builtin code seems to be the only > place in clang where FCMP_TRUE/FCMP_FALSE can ever get emitted anyway, I > guess you might as well implement the workaround (use some other compare to > get the exception) right there, just for X86. I think I'd like to do that as a follow up. This patch as is will at least fix the assertion failure and get the signalling behavior correct for the non- TRUE/FALSE intrinsics. These are going to be far more common to use so fixing those seems like the priority. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D72906/new/ https://reviews.llvm.org/D72906 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
