[libc-commits] [PATCH] D123615: [libc] Automatically add -mfma flag for architectures supporting FMA.

[Tue Ly via Phabricator via libc-commits]

lntue added inline comments.


================
Comment at: libc/test/src/math/CMakeLists.txt:1204-1205
     libc.src.__support.FPUtil.fputil
+  FLAGS
+    FMA_OPT__ONLY
 )
----------------
gchatelet wrote:
> I'm not sure I understand the semantic here. Does that mean that the test requires FMA?
> If so does it? It would make sense to test it with and without FMA.
> 
> Maybe I missed something.
Yes, for this patch, this test does require FMA.  That is because without FMA instructions, the current expm1f implementation is not correctly rounded for all float inputs (1 extra exceptional value).  This will be fixed in the followup patch: https://reviews.llvm.org/D123440


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D123615/new/

https://reviews.llvm.org/D123615