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authorEmilio G. Cota <cota@braap.org>2016-06-08 14:55:24 -0400
committerRichard Henderson <rth@twiddle.net>2016-06-11 23:10:18 +0000
commitdc8b295d05ec35a8c032f9abca421772347ba5d4 (patch)
treecfb4f6cbacaacff3d1a087ebdf68b959ff76c3d3 /include/exec
parentac9a9eba1e43c5354905c0c7f8e17852ed396ac2 (diff)
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exec: add tb_hash_func5, derived from xxhash
This will be used by upcoming changes for hashing the tb hash. Add this into a separate file to include the copyright notice from xxhash. Reviewed-by: Sergey Fedorov <sergey.fedorov@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net> Signed-off-by: Emilio G. Cota <cota@braap.org> Message-Id: <1465412133-3029-7-git-send-email-cota@braap.org> Signed-off-by: Richard Henderson <rth@twiddle.net>
Diffstat (limited to 'include/exec')
-rw-r--r--include/exec/tb-hash-xx.h94
1 files changed, 94 insertions, 0 deletions
diff --git a/include/exec/tb-hash-xx.h b/include/exec/tb-hash-xx.h
new file mode 100644
index 0000000..9f3fc05
--- /dev/null
+++ b/include/exec/tb-hash-xx.h
@@ -0,0 +1,94 @@
+/*
+ * xxHash - Fast Hash algorithm
+ * Copyright (C) 2012-2016, Yann Collet
+ *
+ * BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * + Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * + Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * You can contact the author at :
+ * - xxHash source repository : https://github.com/Cyan4973/xxHash
+ */
+#ifndef EXEC_TB_HASH_XX
+#define EXEC_TB_HASH_XX
+
+#include <qemu/bitops.h>
+
+#define PRIME32_1 2654435761U
+#define PRIME32_2 2246822519U
+#define PRIME32_3 3266489917U
+#define PRIME32_4 668265263U
+#define PRIME32_5 374761393U
+
+#define TB_HASH_XX_SEED 1
+
+/*
+ * xxhash32, customized for input variables that are not guaranteed to be
+ * contiguous in memory.
+ */
+static inline
+uint32_t tb_hash_func5(uint64_t a0, uint64_t b0, uint32_t e)
+{
+ uint32_t v1 = TB_HASH_XX_SEED + PRIME32_1 + PRIME32_2;
+ uint32_t v2 = TB_HASH_XX_SEED + PRIME32_2;
+ uint32_t v3 = TB_HASH_XX_SEED + 0;
+ uint32_t v4 = TB_HASH_XX_SEED - PRIME32_1;
+ uint32_t a = a0 >> 32;
+ uint32_t b = a0;
+ uint32_t c = b0 >> 32;
+ uint32_t d = b0;
+ uint32_t h32;
+
+ v1 += a * PRIME32_2;
+ v1 = rol32(v1, 13);
+ v1 *= PRIME32_1;
+
+ v2 += b * PRIME32_2;
+ v2 = rol32(v2, 13);
+ v2 *= PRIME32_1;
+
+ v3 += c * PRIME32_2;
+ v3 = rol32(v3, 13);
+ v3 *= PRIME32_1;
+
+ v4 += d * PRIME32_2;
+ v4 = rol32(v4, 13);
+ v4 *= PRIME32_1;
+
+ h32 = rol32(v1, 1) + rol32(v2, 7) + rol32(v3, 12) + rol32(v4, 18);
+ h32 += 20;
+
+ h32 += e * PRIME32_3;
+ h32 = rol32(h32, 17) * PRIME32_4;
+
+ h32 ^= h32 >> 15;
+ h32 *= PRIME32_2;
+ h32 ^= h32 >> 13;
+ h32 *= PRIME32_3;
+ h32 ^= h32 >> 16;
+
+ return h32;
+}
+
+#endif /* EXEC_TB_HASH_XX */