Index: kernel/arch/amd64/include/memstr.h
===================================================================
--- kernel/arch/amd64/include/memstr.h	(revision 5d494b3f7a42392f3a69ba78ee3c67c3969e5041)
+++ kernel/arch/amd64/include/memstr.h	(revision d68253a4d9f9ef895ded8023f373eff11acfc672)
@@ -89,5 +89,5 @@
 		"addq $1, %0\n\t"
 		"1:\n"
-		: "=a" (ret), "=%S" (d0), "=&D" (d1), "=&c" (d2)
+		: "=a" (ret), "=&S" (d0), "=&D" (d1), "=&c" (d2)
 		: "0" (0), "1" (src), "2" (dst), "3" ((unative_t)cnt)
 	);
@@ -111,5 +111,5 @@
 	asm volatile (
 		"rep stosw\n\t"
-		: "=&D" (d0), "=&c" (d1), "=a" (x)
+		: "=&D" (d0), "=&c" (d1), "=&a" (x)
 		: "0" (dst), "1" ((unative_t)cnt), "2" (x)
 		: "memory"
@@ -133,5 +133,5 @@
 	asm volatile (
 		"rep stosb\n\t"
-		: "=&D" (d0), "=&c" (d1), "=a" (x)
+		: "=&D" (d0), "=&c" (d1), "=&a" (x)
 		: "0" (dst), "1" ((unative_t)cnt), "2" (x)
 		: "memory"