[PATCH] (28/43) alpha xchg fix

[PATCH] (28/43) alpha xchg fix

[Al Viro]

alpha xchg has to be a macro - alpha disables always_inline and if that
puppy does not get inlined, we immediately blow up on undefined reference.
Happens even on gcc3; with gcc4 that happens a _lot_.

Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
----
diff -urN RC13-rc6-git13-pcmcia-irq/include/asm-alpha/system.h RC13-rc6-git13-alpha-xchg/include/asm-alpha/system.h
--- RC13-rc6-git13-pcmcia-irq/include/asm-alpha/system.h	2005-06-17 15:48:29.000000000 -0400
+++ RC13-rc6-git13-alpha-xchg/include/asm-alpha/system.h	2005-08-21 13:17:10.000000000 -0400
@@ -443,22 +443,19 @@
    if something tries to do an invalid xchg().  */
 extern void __xchg_called_with_bad_pointer(void);
 
-static inline unsigned long
-__xchg(volatile void *ptr, unsigned long x, int size)
-{
-	switch (size) {
-		case 1:
-			return __xchg_u8(ptr, x);
-		case 2:
-			return __xchg_u16(ptr, x);
-		case 4:
-			return __xchg_u32(ptr, x);
-		case 8:
-			return __xchg_u64(ptr, x);
-	}
-	__xchg_called_with_bad_pointer();
-	return x;
-}
+#define __xchg(ptr, x, size) \
+({ \
+	unsigned long __xchg__res; \
+	volatile void *__xchg__ptr = (ptr); \
+	switch (size) { \
+		case 1: __xchg__res = __xchg_u8(__xchg__ptr, x); break; \
+		case 2: __xchg__res = __xchg_u16(__xchg__ptr, x); break; \
+		case 4: __xchg__res = __xchg_u32(__xchg__ptr, x); break; \
+		case 8: __xchg__res = __xchg_u64(__xchg__ptr, x); break; \
+		default: __xchg_called_with_bad_pointer(); __xchg__res = x; \
+	} \
+	__xchg__res; \
+})
 
 #define xchg(ptr,x)							     \
   ({									     \

Re: [PATCH] (28/43) alpha xchg fix

[Christoph Hellwig]

On Tue, Aug 23, 2005 at 10:47:07PM +0100, Al Viro wrote:
> alpha xchg has to be a macro - alpha disables always_inline and if that
> puppy does not get inlined, we immediately blow up on undefined reference.
> Happens even on gcc3; with gcc4 that happens a _lot_.

I think you should rather fix alpha to not disable always_inline.  Having
one architecture behaving very different from the others is a rather bad
idea.