Index: cfe/trunk/lib/Frontend/InitPreprocessor.cpp
===================================================================
--- cfe/trunk/lib/Frontend/InitPreprocessor.cpp
+++ cfe/trunk/lib/Frontend/InitPreprocessor.cpp
@@ -830,7 +830,8 @@
   DefineFmt("__UINTPTR", TI.getUIntPtrType(), TI, Builder);
   DefineTypeWidth("__UINTPTR_WIDTH__", TI.getUIntPtrType(), TI, Builder);
 
-  DefineFloatMacros(Builder, "FLT16", &TI.getHalfFormat(), "F16");
+  if (TI.hasFloat16Type())
+    DefineFloatMacros(Builder, "FLT16", &TI.getHalfFormat(), "F16");
   DefineFloatMacros(Builder, "FLT", &TI.getFloatFormat(), "F");
   DefineFloatMacros(Builder, "DBL", &TI.getDoubleFormat(), "");
   DefineFloatMacros(Builder, "LDBL", &TI.getLongDoubleFormat(), "L");
Index: cfe/trunk/test/Headers/float16.c
===================================================================
--- cfe/trunk/test/Headers/float16.c
+++ cfe/trunk/test/Headers/float16.c
@@ -1,7 +1,11 @@
-// RUN: %clang_cc1 -fsyntax-only -verify -std=c89 -ffreestanding %s
-// RUN: %clang_cc1 -fsyntax-only -verify -std=c99 -ffreestanding %s
-// RUN: %clang_cc1 -fsyntax-only -verify -std=c11 -ffreestanding %s
-// RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 -x c++ -ffreestanding %s
+// RUN: %clang_cc1 -triple=aarch64-none-none -fsyntax-only -verify -std=c89 \
+// RUN:   -ffreestanding %s
+// RUN: %clang_cc1 -triple=aarch64-none-none -fsyntax-only -verify \
+// RUN:   -std=c99 -ffreestanding %s
+// RUN: %clang_cc1 -triple=aarch64-none-none -fsyntax-only -verify -std=c11 \
+// RUN:   -ffreestanding %s
+// RUN: %clang_cc1 -triple=aarch64-none-none -fsyntax-only -verify \
+// RUN:   -std=c++11 -x c++ -ffreestanding %s
 // expected-no-diagnostics
 
 #define __STDC_WANT_IEC_60559_TYPES_EXT__
Index: cfe/trunk/test/Preprocessor/init.c
===================================================================
--- cfe/trunk/test/Preprocessor/init.c
+++ cfe/trunk/test/Preprocessor/init.c
@@ -9166,20 +9166,20 @@
 // WEBASSEMBLY-NOT:#define __ELF__
 // WEBASSEMBLY-NEXT:#define __FINITE_MATH_ONLY__ 0
 // WEBASSEMBLY-NEXT:#define __FLOAT128__ 1
-// WEBASSEMBLY-NEXT:#define __FLT16_DECIMAL_DIG__ 5
-// WEBASSEMBLY-NEXT:#define __FLT16_DENORM_MIN__ 5.9604644775390625e-8F16
-// WEBASSEMBLY-NEXT:#define __FLT16_DIG__ 3
-// WEBASSEMBLY-NEXT:#define __FLT16_EPSILON__ 9.765625e-4F16
-// WEBASSEMBLY-NEXT:#define __FLT16_HAS_DENORM__ 1
-// WEBASSEMBLY-NEXT:#define __FLT16_HAS_INFINITY__ 1
-// WEBASSEMBLY-NEXT:#define __FLT16_HAS_QUIET_NAN__ 1
-// WEBASSEMBLY-NEXT:#define __FLT16_MANT_DIG__ 11
-// WEBASSEMBLY-NEXT:#define __FLT16_MAX_10_EXP__ 4
-// WEBASSEMBLY-NEXT:#define __FLT16_MAX_EXP__ 15
-// WEBASSEMBLY-NEXT:#define __FLT16_MAX__ 6.5504e+4F16
-// WEBASSEMBLY-NEXT:#define __FLT16_MIN_10_EXP__ (-13)
-// WEBASSEMBLY-NEXT:#define __FLT16_MIN_EXP__ (-14)
-// WEBASSEMBLY-NEXT:#define __FLT16_MIN__ 6.103515625e-5F16
+// WEBASSEMBLY-NOT:#define __FLT16_DECIMAL_DIG__
+// WEBASSEMBLY-NOT:#define __FLT16_DENORM_MIN__
+// WEBASSEMBLY-NOT:#define __FLT16_DIG__
+// WEBASSEMBLY-NOT:#define __FLT16_EPSILON__
+// WEBASSEMBLY-NOT:#define __FLT16_HAS_DENORM__
+// WEBASSEMBLY-NOT:#define __FLT16_HAS_INFINITY__
+// WEBASSEMBLY-NOT:#define __FLT16_HAS_QUIET_NAN__
+// WEBASSEMBLY-NOT:#define __FLT16_MANT_DIG__
+// WEBASSEMBLY-NOT:#define __FLT16_MAX_10_EXP__
+// WEBASSEMBLY-NOT:#define __FLT16_MAX_EXP__
+// WEBASSEMBLY-NOT:#define __FLT16_MAX__
+// WEBASSEMBLY-NOT:#define __FLT16_MIN_10_EXP__
+// WEBASSEMBLY-NOT:#define __FLT16_MIN_EXP__
+// WEBASSEMBLY-NOT:#define __FLT16_MIN__
 // WEBASSEMBLY-NEXT:#define __FLT_DECIMAL_DIG__ 9
 // WEBASSEMBLY-NEXT:#define __FLT_DENORM_MIN__ 1.40129846e-45F
 // WEBASSEMBLY-NEXT:#define __FLT_DIG__ 6