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authorMattias Andrée <maandree@operamail.com>2014-01-20 07:06:30 +0100
committerMattias Andrée <maandree@operamail.com>2014-01-20 07:06:30 +0100
commit8623a0bf1fb2136a32c172ee48d2ff3274ca2cef (patch)
treea8edb7b10065d2d37cdbc1f3474f00c4c28416f6 /src
parentoptimised parallel parity (diff)
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64-bit instructions for parity on byte
Signed-off-by: Mattias Andrée <maandree@operamail.com>
Diffstat (limited to 'src')
-rw-r--r--src/algorithms/bits/Bits.java11
1 files changed, 11 insertions, 0 deletions
diff --git a/src/algorithms/bits/Bits.java b/src/algorithms/bits/Bits.java
index 8625310..3101217 100644
--- a/src/algorithms/bits/Bits.java
+++ b/src/algorithms/bits/Bits.java
@@ -64,6 +64,17 @@ public class Bits
private static byte[] PARITY_TABLE_256 = { £(parity-table 4 0) };
+ /**
+ * Compute the parity of all bits in an integer, 64-bit multiply–modulus version
+ *
+ * @param value The interger
+ * @return The parity
+ */
+ public static int parity_64bit(byte value)
+ {
+ return (int)(((value * 0x0101010101010101L) & 0x8040201008040201L) % 0x1FF) & 1;
+ }
+
£<for T_S in char_2 byte_1 short_2 int_4 long_8; do
T=${T_S%_*}
£>S=${T_S#*_}