[PATCH] D12633: Implement ACLE 2.0 macros of chapters 6.6 and 6.7 for [ARM] and [Aarch64] targets

[Renato Golin via cfe-commits]

rengolin added reviewers: rsmith, t.p.northover.
rengolin added a comment.

Adding Richard Smith, as he was the one choosing C99/!freestanding for runtime rounding.


================
Comment at: lib/Basic/Targets.cpp:4790
@@ -4779,1 +4789,3 @@
+    if (!Opts.C11)
+      Builder.defineMacro("__SUPPORT_SNAN__", "1");
   }
----------------
labrinea wrote:
> rengolin wrote:
> > Er, well, the ACLE doc says it wasn't adopted in C11, but that doesn't mean that it was present in all others, just that there is a proposal for C11 which wasn't accepted.
> > 
> > I think this macro needs some other mechanism to be set, and unless Clang/LLVM supports signaling NANs unconditionally, we shouldn't add it.
> Maybe we could skip this macro in this patch? @richard.barton.arm
If this item sparks controversy, we should keep it out. For now, I'm interested in what Tim and Richard(s) have to say.


http://reviews.llvm.org/D12633