[PATCH] D12244: Implement ACLE 2.0 macros of chapters 6.4 and 6.5 for [ARM] and [Aarch64] targets

[Alexandros Lamprineas via cfe-commits]

labrinea added inline comments.

================
Comment at: lib/Basic/Targets.cpp:4685-4686
@@ +4684,4 @@
+    // ACLE 6.5.2 Half-precision (16-bit) floating-point format
+    if (HW_FP & HW_FP_HP)
+      Builder.defineMacro("__ARM_FP16_FORMAT_IEEE", "1");
+
----------------
olista01 wrote:
> The __fp16 type is accepted even if it is not supported by the hardware (library calls are emitted instead), so this can be defined unconditionally. I'm currently working on D12148, which also sets this and _ARM_FP16_ARGS.
Good point. As far as I know there is hardware support for having _fp16 type values as function arguments but not as return values (yet). If so, should _ARM_FP16_ARGS macro be defined or not? (ACLE 2.0: "_ARM_FP16_ARGS is defined to 1 if __fp16 can be used as an argument and result.")


http://reviews.llvm.org/D12244