Fix x86_atomic_{set|clear}bits_u64() by using the "er" constraint instead

of "ir" as the orq and andq instructions take a 32-bit immedate argument that
gets sign-extended.

ok mikeb@

diff --git a/sys/arch/amd64/include/atomic.h b/sys/arch/amd64/include/atomic.h
index 4ec437c..8ac0804 100644 (file)
--- a/sys/arch/amd64/include/atomic.h
+++ b/sys/arch/amd64/include/atomic.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: atomic.h,v 1.17 2015/01/06 00:38:32 dlg Exp $ */
+/*     $OpenBSD: atomic.h,v 1.18 2016/08/17 11:56:42 kettenis Exp $    */
 /*     $NetBSD: atomic.h,v 1.1 2003/04/26 18:39:37 fvdl Exp $  */
 
 /*
@@ -293,23 +293,16 @@ x86_atomic_clearbits_u32(volatile u_int32_t *ptr, u_int32_t bits)
        __asm volatile(LOCK " andl %1,%0" :  "=m" (*ptr) : "ir" (~bits));
 }
 
-/*
- * XXX XXX XXX
- * theoretically 64bit cannot be used as
- * an "i" and thus if we ever try to give
- * these anything from the high dword there
- * is an asm error pending
- */
 static __inline void
 x86_atomic_setbits_u64(volatile u_int64_t *ptr, u_int64_t bits)
 {
-       __asm volatile(LOCK " orq %1,%0" :  "=m" (*ptr) : "ir" (bits));
+       __asm volatile(LOCK " orq %1,%0" :  "=m" (*ptr) : "er" (bits));
 }
 
 static __inline void
 x86_atomic_clearbits_u64(volatile u_int64_t *ptr, u_int64_t bits)
 {
-       __asm volatile(LOCK " andq %1,%0" :  "=m" (*ptr) : "ir" (~bits));
+       __asm volatile(LOCK " andq %1,%0" :  "=m" (*ptr) : "er" (~bits));
 }
 
 #define x86_atomic_testset_ul  x86_atomic_testset_u64