On Mon, Mar 06, 2006 at 05:05:52PM -0800, Andrew Morton wrote:
> I worry about what impact that change might have on code generation.
> Hopefully none, if gcc is good enough.
>
> But I cannot think of a better fix.
Below's fix results in exactly the same code size on all compilers and
configurations I've tested it.
I also have another more elegant fix which as a side effect makes
get_unaligned work for arbitrary data types but it that one results in a
slight code bloat:
gcc 4.1.0 ip22 64-bit
text data bss dec hex filename
2717213 337920 167968 3223101 312e3d vmlinux
2717277 337920 167968 3223165 312e7d vmlinux unaligned-4.patch
Ralf
Signed-off-by: Ralf Baechle <[email protected]>
diff --git a/include/asm-generic/unaligned.h b/include/asm-generic/unaligned.h
index 4dc8ddb..9a63564 100644
--- a/include/asm-generic/unaligned.h
+++ b/include/asm-generic/unaligned.h
@@ -26,35 +26,13 @@
* the linker will alert us to the problem via an unresolved reference
* error.
*/
-extern void bad_unaligned_access_length(void) __attribute__((noreturn));
+extern int bad_unaligned_access_length(void) __attribute__((noreturn));
struct __una_u64 { __u64 x __attribute__((packed)); };
struct __una_u32 { __u32 x __attribute__((packed)); };
struct __una_u16 { __u16 x __attribute__((packed)); };
/*
- * Elemental unaligned loads
- */
-
-static inline __u64 __uldq(const __u64 *addr)
-{
- const struct __una_u64 *ptr = (const struct __una_u64 *) addr;
- return ptr->x;
-}
-
-static inline __u32 __uldl(const __u32 *addr)
-{
- const struct __una_u32 *ptr = (const struct __una_u32 *) addr;
- return ptr->x;
-}
-
-static inline __u16 __uldw(const __u16 *addr)
-{
- const struct __una_u16 *ptr = (const struct __una_u16 *) addr;
- return ptr->x;
-}
-
-/*
* Elemental unaligned stores
*/
@@ -76,26 +54,16 @@ static inline void __ustw(__u16 val, __u
ptr->x = val;
}
-#define __get_unaligned(ptr, size) ({ \
- const void *__gu_p = ptr; \
- __typeof__(*(ptr)) val; \
- switch (size) { \
- case 1: \
- val = *(const __u8 *)__gu_p; \
- break; \
- case 2: \
- val = __uldw(__gu_p); \
- break; \
- case 4: \
- val = __uldl(__gu_p); \
- break; \
- case 8: \
- val = __uldq(__gu_p); \
- break; \
- default: \
- bad_unaligned_access_length(); \
- }; \
- val; \
+#define __get_unaligned(ptr, size) \
+({ \
+ const void *__gu_p = ptr; \
+ int __sz = size; \
+ \
+ ((__sz == 1) ? (__typeof__(*(ptr)))*(const __u8 *)__gu_p \
+ : ((__sz == 2) ? (__typeof__(*(ptr)))((struct __una_u16 *)__gu_p)->x \
+ : ((__sz == 4) ? (__typeof__(*(ptr)))((struct __una_u32 *)__gu_p)->x \
+ : ((__sz == 8) ? (__typeof__(*(ptr)))((struct __una_u64 *)__gu_p)->x \
+ : bad_unaligned_access_length())))); \
})
#define __put_unaligned(val, ptr, size) \
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
