Emit Tag_ABI_FP_16bit_format build attribute.

The __fp16 type is unconditionally exposed. Since -mfp16-format is not yet
supported, there is not a user switch to change this behaviour. This build
attribute should capture the default behaviour of the compiler, which is to
expose the IEEE 754 version of __fp16.

When -mfp16-format is emitted, that will be the way to control the value of
this build attribute.

Change-Id: I8a46641ff0fd2ef8ad0af5f482a6d1af2ac3f6b0
llvm-svn: 224115

1 files changed, 7 insertions, 0 deletions

diff --git a/llvm/lib/Target/ARM/ARMAsmPrinter.cpp b/llvm/lib/Target/ARM/ARMAsmPrinter.cpp
index d3fdbcca2dd..0300f5875ca 100644
--- a/llvm/lib/Target/ARM/ARMAsmPrinter.cpp
+++ b/llvm/lib/Target/ARM/ARMAsmPrinter.cpp
@@ -782,6 +782,13 @@ void ARMAsmPrinter::emitAttributes() {
   if (Subtarget->hasFP16())
       ATS.emitAttribute(ARMBuildAttrs::FP_HP_extension, ARMBuildAttrs::AllowHPFP);
 
+  // FIXME: To support emitting this build attribute as GCC does, the
+  // -mfp16-format option and associated plumbing must be
+  // supported. For now the __fp16 type is exposed by default, so this
+  // attribute should be emitted with value 1.
+  ATS.emitAttribute(ARMBuildAttrs::ABI_FP_16bit_format,
+                    ARMBuildAttrs::FP16FormatIEEE);
+
   if (Subtarget->hasMPExtension())
       ATS.emitAttribute(ARMBuildAttrs::MPextension_use, ARMBuildAttrs::AllowMP);