include/linux/compiler-gcc.h: improve __visible documentation
authorAndrew Morton <akpm@linux-foundation.org>
Sat, 7 Nov 2015 00:30:09 +0000 (16:30 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Sat, 7 Nov 2015 01:50:42 +0000 (17:50 -0800)
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
include/linux/compiler-gcc.h

index 0e3110a0b771551191c58ec95e4c04fb1262c5d8..22ab246feed34c104038d3f94e1401ea9a587f8f 100644 (file)
 
 #if GCC_VERSION >= 40600
 /*
- * Tell the optimizer that something else uses this function or variable.
+ * When used with Link Time Optimization, gcc can optimize away C functions or
+ * variables which are referenced only from assembly code.  __visible tells the
+ * optimizer that something else uses this function or variable, thus preventing
+ * this.
  */
 #define __visible      __attribute__((externally_visible))
 #endif