[flang-commits] [clang] [flang] [Flang][Driver] Deprecate Ofast (PR #101701)

[Leandro Lupori via flang-commits]

================
@@ -933,10 +933,12 @@ def O : Joined<["-"], "O">, Group<O_Group>,
 def O_flag : Flag<["-"], "O">, Visibility<[ClangOption, CC1Option, FC1Option]>,
   Alias<O>, AliasArgs<["1"]>;
 def Ofast : Joined<["-"], "Ofast">, Group<O_Group>,
-  Visibility<[ClangOption, CC1Option, FlangOption]>,
-  HelpTextForVariants<[ClangOption, CC1Option],
-                      "Deprecated; use '-O3 -ffast-math' for the same behavior,"
-                      " or '-O3' to enable only conforming optimizations">;
+  Visibility<[ClangOption, CC1Option, FlangOption, FC1Option]>,
+  HelpTextForVariants<[FlangOption, FC1Option],
+    "Deprecated; use '-O3 -ffast-math -fstack-arrays' for the same behavior,"
+    " or '-O3 -fstack-arrays' to enable only conforming optimizations">,
----------------
luporl wrote:

This may be out of the scope of this change, but why isn't `-fstack-arrays` enabled with `-O3`?

If `-fstack-arrays` is not specified are array temporaries always allocated on the heap?

https://github.com/llvm/llvm-project/pull/101701