[PATCH 4.15 042/163] compiler-gcc.h: Introduce __optimize function attribute

[Greg Kroah-Hartman]

4.15-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>

commit df5d45aa08f848b79caf395211b222790534ccc7 upstream.

Create a new function attribute __optimize, which allows to specify an
optimization level on a per-function basis.

Signed-off-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Acked-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 include/linux/compiler-gcc.h |    4 ++++
 include/linux/compiler.h     |    4 ++++
 2 files changed, 8 insertions(+)

--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -196,6 +196,10 @@
 #endif /* __CHECKER__ */
 #endif /* GCC_VERSION >= 40300 */
 
+#if GCC_VERSION >= 40400
+#define __optimize(level)	__attribute__((__optimize__(level)))
+#endif /* GCC_VERSION >= 40400 */
+
 #if GCC_VERSION >= 40500
 
 #ifndef __CHECKER__
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -271,6 +271,10 @@ static __always_inline void __write_once
 
 #endif /* __ASSEMBLY__ */
 
+#ifndef __optimize
+# define __optimize(level)
+#endif
+
 /* Compile time object size, -1 for unknown */
 #ifndef __compiletime_object_size
 # define __compiletime_object_size(obj) -1