Merge branch 'x86/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

torvalds · torvalds · commit 050026feae5b · 2010-09-27T21:19:27.000-07:00
* 'x86/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: Avoid 'constant_test_bit()' misoptimization due to cast to non-volatile
diff --git a/arch/x86/include/asm/bitops.h b/arch/x86/include/asm/bitops.h
@@ -309,7 +309,7 @@ static inline int test_and_change_bit(int nr, volatile unsigned long *addr)
 static __always_inline int constant_test_bit(unsigned int nr, const volatile unsigned long *addr)
 {
 	return ((1UL << (nr % BITS_PER_LONG)) &
-		(((unsigned long *)addr)[nr / BITS_PER_LONG])) != 0;
+		(addr[nr / BITS_PER_LONG])) != 0;
 }
 
 static inline int variable_test_bit(int nr, volatile const unsigned long *addr)

Original file line number	Diff line number	Diff line change
`@@ -309,7 +309,7 @@ static inline int test_and_change_bit(int nr, volatile unsigned long *addr)`
`309`	`309`	`static __always_inline int constant_test_bit(unsigned int nr, const volatile unsigned long *addr)`
`310`	`310`	`{`
`311`	`311`	`return ((1UL << (nr % BITS_PER_LONG)) &`
`312`		`- (((unsigned long *)addr)[nr / BITS_PER_LONG])) != 0;`
	`312`	`+ (addr[nr / BITS_PER_LONG])) != 0;`
`313`	`313`	`}`
`314`	`314`
`315`	`315`	`static inline int variable_test_bit(int nr, volatile const unsigned long *addr)`