Index: include/llvm/Support/Compiler.h
===================================================================
--- include/llvm/Support/Compiler.h
+++ include/llvm/Support/Compiler.h
@@ -217,6 +217,12 @@
 #define LLVM_ATTRIBUTE_RETURNS_NONNULL
 #endif
 
+#if __has_attribute(hot)
+#define LLVM_HOT __attribute__((__hot__))
+#else
+#define LLVM_HOT
+#endif
+
 /// \macro LLVM_ATTRIBUTE_RETURNS_NOALIAS Used to mark a function as returning a
 /// pointer that does not alias any other valid pointer.
 #ifdef __GNUC__