BN_usub: Don't copy when r and a the same

[openssl.git] / crypto / bn / bn_add.c

diff --git a/crypto/bn/bn_add.c b/crypto/bn/bn_add.c
index ccdcdd1d7cbd58ac39b24b219a5ce3485231af7f..bbb05842452e6558fead3bc84a1cb9cd1482ebbb 100644 (file)
--- a/crypto/bn/bn_add.c
+++ b/crypto/bn/bn_add.c
@@ -56,7 +56,7 @@
  * [including the GNU Public Licence.]
  */
 
-#include "cryptlib.h"
+#include "internal/cryptlib.h"
 #include "bn_lcl.h"
 
 /* r can == a or b */
@@ -68,12 +68,12 @@ int BN_add(BIGNUM *r, const BIGNUM *a, const BIGNUM *b)
     bn_check_top(a);
     bn_check_top(b);
 
-        /*-
-         *  a +  b      a+b
-         *  a + -b      a-b
-         * -a +  b      b-a
-         * -a + -b      -(a+b)
-         */
+    /*-
+     *  a +  b      a+b
+     *  a + -b      a-b
+     * -a +  b      b-a
+     * -a + -b      -(a+b)
+     */
     if (a_neg ^ b->neg) {
         /* only one is negative */
         if (a_neg) {
@@ -222,28 +222,8 @@ int BN_usub(BIGNUM *r, const BIGNUM *a, const BIGNUM *b)
                 break;
         }
     }
-#if 0
-    memcpy(rp, ap, sizeof(*rp) * (max - i));
-#else
-    if (rp != ap) {
-        for (;;) {
-            if (!dif--)
-                break;
-            rp[0] = ap[0];
-            if (!dif--)
-                break;
-            rp[1] = ap[1];
-            if (!dif--)
-                break;
-            rp[2] = ap[2];
-            if (!dif--)
-                break;
-            rp[3] = ap[3];
-            rp += 4;
-            ap += 4;
-        }
-    }
-#endif
+    if (dif && ap != rp)
+        memcpy(rp, ap, sizeof(*rp) * dif);
 
     r->top = max;
     r->neg = 0;
@@ -260,12 +240,12 @@ int BN_sub(BIGNUM *r, const BIGNUM *a, const BIGNUM *b)
     bn_check_top(a);
     bn_check_top(b);
 
-        /*-
-         *  a -  b      a-b
-         *  a - -b      a+b
-         * -a -  b      -(a+b)
-         * -a - -b      b-a
-         */
+    /*-
+     *  a -  b      a-b
+     *  a - -b      a+b
+     * -a -  b      -(a+b)
+     * -a - -b      b-a
+     */
     if (a->neg) {
         if (b->neg) {
             tmp = a;