Merge commit 'f07ccd6e4fbc5bbfeb94d40e0f14bc527a7d5439' as 'cpp/simdcomp'

cpp/simdcomp/include/simdcomputil.h

@@ -0,0 +1,54 @@
+/**
+ * This code is released under a BSD License.
+ */
+
+#ifndef SIMDCOMPUTIL_H_
+#define SIMDCOMPUTIL_H_
+
+#include "portability.h"
+
+/* SSE2 is required */
+#include <emmintrin.h>
+
+
+
+
+/* returns the integer logarithm of v (bit width) */
+uint32_t bits(const uint32_t v);
+
+/* max integer logarithm over a range of SIMDBlockSize integers (128 integer) */
+uint32_t maxbits(const uint32_t * begin);
+
+/* same as maxbits, but we specify the number of integers */
+uint32_t maxbits_length(const uint32_t * in,uint32_t length);
+
+enum{ SIMDBlockSize = 128};
+
+
+/* computes (quickly) the minimal value of 128 values */
+uint32_t simdmin(const uint32_t * in);
+
+/* computes (quickly) the minimal value of the specified number of values */
+uint32_t simdmin_length(const uint32_t * in, uint32_t length);
+
+#ifdef __SSE4_1__
+/* computes (quickly) the minimal and maximal value of the specified number of values */
+void simdmaxmin_length(const uint32_t * in, uint32_t length, uint32_t * getmin, uint32_t * getmax);
+
+/* computes (quickly) the minimal and maximal value of the 128 values */
+void simdmaxmin(const uint32_t * in, uint32_t * getmin, uint32_t * getmax);
+
+#endif
+
+/* like maxbit over 128 integers (SIMDBlockSize) with provided initial value 
+   and using differential coding */
+uint32_t simdmaxbitsd1(uint32_t initvalue, const uint32_t * in);
+
+/* like simdmaxbitsd1, but calculates maxbits over |length| integers 
+   with provided initial value. |length| can be any arbitrary value. */
+uint32_t simdmaxbitsd1_length(uint32_t initvalue, const uint32_t * in,
+                uint32_t length);
+
+
+
+#endif /* SIMDCOMPUTIL_H_ */