From e336912cf9f1cc7a7d5f1285ae853c9155270981 Mon Sep 17 00:00:00 2001
From: Peter Dettman <peter.dettman@bouncycastle.org>
Date: Thu, 3 Oct 2013 10:31:16 +0700
Subject: Add a couple more "registers" to remove 1/4 of shift-adds

---
 .../java/org/bouncycastle/math/ec/LongArray.java   | 34 ++++++++++++++++++----
 1 file changed, 28 insertions(+), 6 deletions(-)

(limited to 'core/src/main/java/org/bouncycastle/math')

diff --git a/core/src/main/java/org/bouncycastle/math/ec/LongArray.java b/core/src/main/java/org/bouncycastle/math/ec/LongArray.java
index ad3e6225..4b972fc6 100644
--- a/core/src/main/java/org/bouncycastle/math/ec/LongArray.java
+++ b/core/src/main/java/org/bouncycastle/math/ec/LongArray.java
@@ -521,35 +521,52 @@ class LongArray
         long[] c1 = new long[cLen];
         long[] c2 = new long[cLen];
         long[] c3 = new long[cLen];
+        long[] c10 = new long[cLen];
+        long[] c32 = new long[cLen];
 
-        long bit1 = 1L << 48;
+        long bit3 = 1L << 48;
 
         for (;;)
         {
-            long bit2 = bit1 >>> 16, bit3 = bit2 >>> 16, bit4 = bit3 >>> 16;
+            long bit2 = bit3 >>> 16, bit1 = bit2 >>> 16, bit0 = bit1 >>> 16;
+            long bit32 = bit3 | bit2, bit10 = bit1 | bit0;
 
             for (int aPos = 0; aPos < aLen; ++aPos)
             {
                 long aVal = a[aPos];
-                if ((aVal & bit1) != 0)
+
+                if ((aVal & bit32) == bit32)
+                {
+                    addShiftedByWordsQuick(c32, aPos, b);
+                }
+                else
+                if ((aVal & bit3) != 0)
                 {
                     addShiftedByWordsQuick(c3, aPos, b);
                 }
+                else
                 if ((aVal & bit2) != 0)
                 {
                     addShiftedByWordsQuick(c2, aPos, b);
                 }
-                if ((aVal & bit3) != 0)
+
+                if ((aVal & bit10) == bit10)
+                {
+                    addShiftedByWordsQuick(c10, aPos, b);
+                }
+                else
+                if ((aVal & bit1) != 0)
                 {
                     addShiftedByWordsQuick(c1, aPos, b);
                 }
-                if ((aVal & bit4) != 0)
+                else
+                if ((aVal & bit0) != 0)
                 {
                     addShiftedByWordsQuick(c0, aPos, b);
                 }
             }
 
-            if ((bit1 <<= 1) == 0L)
+            if ((bit3 <<= 1) == 0L)
             {
                 break;
             }
@@ -557,6 +574,11 @@ class LongArray
             shiftLeftQuick(b);
         }
 
+        addQuick(c3, c32, cLen);
+        addQuick(c2, c32, cLen);
+        addQuick(c1, c10, cLen);
+        addQuick(c0, c10, cLen);
+
         addShiftedByBitsQuick(c0, c1, cLen, 16);
         addShiftedByBitsQuick(c0, c2, cLen, 32);
         addShiftedByBitsQuick(c0, c3, cLen, 48);
-- 
cgit v1.2.3