akr	2013-07-22 00:17:09 +0900 (Mon, 22 Jul 2013)

  New Revision: 42097

  http://svn.ruby-lang.org/cgi-bin/viewvc.cgi?view=rev&revision=42097

  Log:
    * bignum.c (bary_sq_fast): Refine expressions.

  Modified files:
    trunk/ChangeLog
    trunk/bignum.c

Index: ChangeLog
===================================================================
--- ChangeLog	(revision 42096)
+++ ChangeLog	(revision 42097)
@@ -1,3 +1,7 @@ https://github.com/ruby/ruby/blob/trunk/ChangeLog#L1
+Mon Jul 22 00:15:20 2013  Tanaka Akira  <akr@f...>
+
+	* bignum.c (bary_sq_fast): Refine expressions.
+
 Sun Jul 21 21:08:59 2013  Tanaka Akira  <akr@f...>
 
 	* bignum.c (bary_mul): Use simple multiplication if yl is small.
Index: bignum.c
===================================================================
--- bignum.c	(revision 42096)
+++ bignum.c	(revision 42097)
@@ -1601,6 +1601,8 @@ bary_sq_fast(BDIGIT *zds, size_t zn, BDI https://github.com/ruby/ruby/blob/trunk/bignum.c#L1601
 {
     size_t i, j;
     BDIGIT_DBL c, v, w;
+    BDIGIT vl;
+    int vh;
 
     assert(xn * 2 <= zn);
 
@@ -1617,12 +1619,14 @@ bary_sq_fast(BDIGIT *zds, size_t zn, BDI https://github.com/ruby/ruby/blob/trunk/bignum.c#L1619
 	zds[i + i] = BIGLO(c);
 	c = BIGDN(c);
 	v *= 2;
+        vl = BIGLO(v);
+        vh = (int)BIGDN(v);
 	for (j = i + 1; j < xn; j++) {
 	    w = (BDIGIT_DBL)xds[j];
-	    c += (BDIGIT_DBL)zds[i + j] + BIGLO(v) * w;
+	    c += (BDIGIT_DBL)zds[i + j] + vl * w;
 	    zds[i + j] = BIGLO(c);
 	    c = BIGDN(c);
-	    if (BIGDN(v))
+	    if (vh)
                 c += w;
 	}
 	if (c) {
@@ -1642,8 +1646,7 @@ bary_sq_fast(BDIGIT *zds, size_t zn, BDI https://github.com/ruby/ruby/blob/trunk/bignum.c#L1646
     zds[i + i] = BIGLO(c);
     c = BIGDN(c);
     if (c) {
-        c += (BDIGIT_DBL)zds[i + xn];
-        zds[i + xn] = BIGLO(c);
+        zds[i + xn] += BIGLO(c);
     }
 }
 

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