From 465b01edc815c64b2025d6412fcebacd72edde36 Mon Sep 17 00:00:00 2001
From: Mattias Andrée <maandree@operamail.com>
Date: Mon, 20 Jan 2014 07:01:54 +0100
Subject: optimised parallel parity
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Signed-off-by: Mattias Andrée <maandree@operamail.com>
---
src/algorithms/bits/Bits.java | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
(limited to 'src/algorithms/bits')
diff --git a/src/algorithms/bits/Bits.java b/src/algorithms/bits/Bits.java
index 3dfeca4..8625310 100644
--- a/src/algorithms/bits/Bits.java
+++ b/src/algorithms/bits/Bits.java
@@ -314,6 +314,24 @@ public class Bits
value ^= value >> 8;
return PARITY_TABLE_256[(int)value];
}
+
+ /**
+ * Compute the parity of all bits in an integer, optimised parallel version
+ *
+ * @param value The interger
+ * @return The parity
+ */
+ public static int parity_optimised_parallel(£{T} value)
+ {
+£>(( $S > 4 )) &&
+ value ^= value >> 32;
+£>(( $S > 2 )) &&
+ value ^= value >> 16;
+£>(( $S > 1 )) &&
+ value ^= value >> 8;
+ value ^= value >> 4;
+ return (0x6996 >> (value & 15)) & 1;
+ }
£>done
}
--
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