[PATCH] D37302: [Headers] Define *_HAS_SUBNORM for FLT, DBL, LDBL

[Pirama Arumuga Nainar via Phabricator via llvm-commits]

pirama added a comment.

In https://reviews.llvm.org/D37302#871794, @joerg wrote:

> So what about targets that don't support subnormals? I'm moderately sure ARM falls into this category given the right phase of the moon.


Clang defines `__FLT_HAS_DENORM__` and friends unconditionally, so I thought we could do this for `FLT_HAS_SUBNORM` as well, considering that gcc did the same.  But that might be misleading because gcc's float.h was just for the target of that particular gcc build.

Am I right to understand that `__FLT_HAS_DENORM__` signifies *compiler* support for denorms as opposed to support on the *platforms* supported?  If so, it might support our alternative consideration of defining these macros in the bionic/libc headers for Android (and rely on the include_next similar to Windows and Darwin).


https://reviews.llvm.org/D37302