x86: Convert BUG() to use unreachable()

Use the new unreachable() macro instead of for(;;);.  When
allyesconfig is built with a GCC-4.5 snapshot on i686 the size of the
text segment is reduced by 3987 bytes (from 6827019 to 6823032).

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Acked-by: "H. Peter Anvin" <hpa@zytor.com>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Ingo Molnar <mingo@redhat.com>
CC: x86@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/x86/include/asm/bug.h b/arch/x86/include/asm/bug.h
index d9cf1cd..f654d1b 100644 (file)
--- a/arch/x86/include/asm/bug.h
+++ b/arch/x86/include/asm/bug.h
@@ -22,14 +22,14 @@ do {                                                                \
                     ".popsection"                              \
                     : : "i" (__FILE__), "i" (__LINE__),        \
                     "i" (sizeof(struct bug_entry)));           \
-       for (;;) ;                                              \
+       unreachable();                                          \
 } while (0)
 
 #else
 #define BUG()                                                  \
 do {                                                           \
        asm volatile("ud2");                                    \
-       for (;;) ;                                              \
+       unreachable();                                          \
 } while (0)
 #endif