diff --git a/qemu/target-arm/helper-a64.c b/qemu/target-arm/helper-a64.c
index 02ecd378..529a77d2 100644
--- a/qemu/target-arm/helper-a64.c
+++ b/qemu/target-arm/helper-a64.c
@@ -68,20 +68,7 @@ uint32_t HELPER(clz32)(uint32_t x)
 
 uint64_t HELPER(rbit64)(uint64_t x)
 {
-    /* assign the correct byte position */
-    x = bswap64(x);
-
-    /* assign the correct nibble position */
-    x = ((x & 0xf0f0f0f0f0f0f0f0ULL) >> 4)
-        | ((x & 0x0f0f0f0f0f0f0f0fULL) << 4);
-
-    /* assign the correct bit position */
-    x = ((x & 0x8888888888888888ULL) >> 3)
-        | ((x & 0x4444444444444444ULL) >> 1)
-        | ((x & 0x2222222222222222ULL) << 1)
-        | ((x & 0x1111111111111111ULL) << 3);
-
-    return x;
+    return revbit64(x);
 }
 
 /* Convert a softfloat float_relation_ (as returned by
diff --git a/qemu/target-arm/helper.c b/qemu/target-arm/helper.c
index 49804a1b..e35656a4 100644
--- a/qemu/target-arm/helper.c
+++ b/qemu/target-arm/helper.c
@@ -3146,17 +3146,7 @@ uint32_t HELPER(udiv)(uint32_t num, uint32_t den)
 
 uint32_t HELPER(rbit)(uint32_t x)
 {
-    x =  ((x & 0xff000000) >> 24)
-       | ((x & 0x00ff0000) >> 8)
-       | ((x & 0x0000ff00) << 8)
-       | ((x & 0x000000ff) << 24);
-    x =  ((x & 0xf0f0f0f0) >> 4)
-       | ((x & 0x0f0f0f0f) << 4);
-    x =  ((x & 0x88888888) >> 3)
-       | ((x & 0x44444444) >> 1)
-       | ((x & 0x22222222) << 1)
-       | ((x & 0x11111111) << 3);
-    return x;
+    return revbit32(x);
 }
 
 #if defined(CONFIG_USER_ONLY)