1 files changed, 7 insertions, 0 deletions
diff --git a/arch/x32/atomic_arch.h b/arch/x32/atomic_arch.h
index 7daf4ae2..a744c299 100644
--- a/arch/x32/atomic_arch.h
+++ b/arch/x32/atomic_arch.h
@@ -112,3 +112,10 @@ static inline int a_ctz_l(unsigned long x)
 	__asm__( "bsf %1,%0" : "=r"(x) : "r"(x) );
 	return x;
 }
+
+#define a_clz_64 a_clz_64
+static inline int a_clz_64(uint64_t x)
+{
+	__asm__( "bsr %1,%0 ; xor $63,%0" : "=r"(x) : "r"(x) );
+	return x;
+}