diff -ru linux-2.6.10-rc1/include/asm-generic/div64.h linux-2.6.10-rc1-nsz/include/asm-generic/div64.h
--- linux-2.6.10-rc1/include/asm-generic/div64.h	2004-10-27 10:41:40.000000000 -0700
+++ linux-2.6.10-rc1-nsz/include/asm-generic/div64.h	2004-10-27 10:24:06.000000000 -0700
@@ -22,12 +22,17 @@
 
 #if BITS_PER_LONG == 64
 
-# define do_div(n,base) ({					\
-	uint32_t __base = (base);				\
-	uint32_t __rem;						\
-	__rem = ((uint64_t)(n)) % __base;			\
-	(n) = ((uint64_t)(n)) / __base;				\
-	__rem;							\
+# define do_div(n,base) ({						\
+	uint32_t __rem;							\
+	if (__builtin_constant_p(base) && !((base) & ((base)-1))) {	\
+		__rem = ((uint64_t)(n)) % (base);			\
+		(n) = ((uint64_t)(n)) / (base);				\
+	} else {							\
+		uint32_t __base = (base);				\
+		__rem = ((uint64_t)(n)) % __base;			\
+		(n) = ((uint64_t)(n)) / __base;				\
+	}								\
+	__rem;								\
  })
 
 #elif BITS_PER_LONG == 32
@@ -37,16 +42,21 @@
 /* The unnecessary pointer compare is there
  * to check for type safety (n must be 64bit)
  */
-# define do_div(n,base) ({				\
-	uint32_t __base = (base);			\
-	uint32_t __rem;					\
-	(void)(((typeof((n)) *)0) == ((uint64_t *)0));	\
-	if (likely(((n) >> 32) == 0)) {			\
-		__rem = (uint32_t)(n) % __base;		\
-		(n) = (uint32_t)(n) / __base;		\
-	} else 						\
-		__rem = __div64_32(&(n), __base);	\
-	__rem;						\
+# define do_div(n,base) ({						\
+	uint32_t __rem;						 	\
+	(void)(((typeof((n)) *)0) == ((uint64_t *)0));			\
+	if (__builtin_constant_p(base) && !((base) & ((base)-1))) {     \
+		__rem = ((uint64_t)(n)) % (base);			\
+		(n) = ((uint64_t)(n)) / (base);				\
+	} else {							\
+		uint32_t __base = (base);				\
+		if (likely(((n) >> 32) == 0)) {				\
+			__rem = (uint32_t)(n) % __base;			\
+			(n) = (uint32_t)(n) / __base;			\
+		} else 							\
+			__rem = __div64_32(&(n), __base);		\
+	}								\
+	__rem;								\
  })
 
 #else /* BITS_PER_LONG == ?? */
diff -ru linux-2.6.10-rc1/include/asm-i386/div64.h linux-2.6.10-rc1-nsz/include/asm-i386/div64.h
--- linux-2.6.10-rc1/include/asm-i386/div64.h	2004-10-27 10:41:40.000000000 -0700
+++ linux-2.6.10-rc1-nsz/include/asm-i386/div64.h	2004-10-27 10:15:04.000000000 -0700
@@ -14,16 +14,23 @@
  * convention" on x86.
  */
 #define do_div(n,base) ({ \
-	unsigned long __upper, __low, __high, __mod, __base; \
-	__base = (base); \
-	asm("":"=a" (__low), "=d" (__high):"A" (n)); \
-	__upper = __high; \
-	if (__high) { \
-		__upper = __high % (__base); \
-		__high = __high / (__base); \
+	unsigned long __mod; \
+	if (__builtin_constant_p(base) && !((base) & ((base)-1))) { \
+		__mod = ((uint64_t)(n)) % base;	\
+		(n) = ((uint64_t)(n)) / base; \
+	} else { \
+		unsigned long __upper, __low, __high, __base; \
+		__base = (base); \
+		asm("":"=a" (__low), "=d" (__high):"A" (n)); \
+		__upper = __high; \
+		if (__high) { \
+			__upper = __high % (__base); \
+			__high = __high / (__base); \
+		} \
+		asm("divl %2":	"=a" (__low), "=d" (__mod) : \
+				"rm" (__base), "0" (__low), "1" (__upper)); \
+		asm("":"=A" (n):"a" (__low),"d" (__high)); \
 	} \
-	asm("divl %2":"=a" (__low), "=d" (__mod):"rm" (__base), "0" (__low), "1" (__upper)); \
-	asm("":"=A" (n):"a" (__low),"d" (__high)); \
 	__mod; \
 })