bignum.c: micro optimization

* bignum.c (rb_big_uminus, bigsub_int): use BIGNUM_NEGATE.

* internal.h (BIGNUM_NEGATE): simplify negation.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@53832 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

bignum.c

@@ -5526,7 +5526,7 @@ rb_big_uminus(VALUE x)
 {
     VALUE z = rb_big_clone(x);
 
-    BIGNUM_SET_SIGN(z, !BIGNUM_SIGN(x));
+    BIGNUM_NEGATE(z);
 
     return bignorm(z);
 }
@@ -5624,7 +5624,7 @@ bigsub_int(VALUE x, long y0)
     assert(xn == zn);
     num = (BDIGIT_DBL_SIGNED)xds[0] - y;
     if (xn == 1 && num < 0) {
-	BIGNUM_SET_SIGN(z, !BIGNUM_SIGN(x));
+	BIGNUM_NEGATE(z);
 	zds[0] = (BDIGIT)-num;
 	RB_GC_GUARD(x);
 	return bignorm(z);
@@ -5687,7 +5687,7 @@ bigsub_int(VALUE x, long y0)
     assert(num == 0 || num == -1);
     if (num < 0) {
         get2comp(z);
-	BIGNUM_SET_SIGN(z, !BIGNUM_SIGN(x));
+	BIGNUM_NEGATE(z);
     }
     RB_GC_GUARD(x);
     return bignorm(z);

internal.h

@@ -364,6 +364,7 @@ struct RBignum {
           : (RBASIC(b)->flags &= ~BIGNUM_SIGN_BIT))
 #define BIGNUM_POSITIVE_P(b) BIGNUM_SIGN(b)
 #define BIGNUM_NEGATIVE_P(b) (!BIGNUM_SIGN(b))
+#define BIGNUM_NEGATE(b) (RBASIC(b)->flags ^= BIGNUM_SIGN_BIT)
 
 #define BIGNUM_EMBED_FLAG FL_USER2
 #define BIGNUM_EMBED_LEN_MASK (FL_USER5|FL_USER4|FL_USER3)