Add more missing files.

git-svn-id: http://svn.drobilla.net/zix/trunk@101 df6676b4-ccc9-40e5-b5d6-7c4628a128e3

1 files changed, 121 insertions, 0 deletions

diff --git a/zix/trie_util.h b/zix/trie_util.h
new file mode 100644
index 0000000..45cc1f1
--- /dev/null
+++ b/zix/trie_util.h
@@ -0,0 +1,121 @@
+/*
+  Copyright 2014 David Robillard <http://drobilla.net>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#ifndef ZIX_TRIE_UTIL_H
+#define ZIX_TRIE_UTIL_H
+
+#ifdef __SSE4_2__
+#    include <smmintrin.h>
+#endif
+
+#ifdef ZIX_TRIE_LINEAR_SEARCH
+
+/** Return the index of `k` in `keys`, or `n` if not found. */
+ZIX_PRIVATE size_t
+zix_trie_find_key(const uint8_t* const keys, const size_t n, const uint8_t k)
+{
+	for (size_t i = 0; i < n; ++i) {
+		if (keys[i] == k) {
+			assert(keys[i] >= k);
+			return i;
+		}
+	}
+	return n;
+}
+
+#else
+
+/** Return the index of the first element in `keys` >= `k`, or `n`. */
+ZIX_PRIVATE size_t
+zix_trie_find_key(const uint8_t* const keys, const size_t n, const uint8_t k)
+{
+	size_t first = 0;
+	size_t len   = n;
+	while (len > 0) {
+		const size_t half = len >> 1;
+		const size_t i    = first + half;
+		if (keys[i] < k) {
+			const size_t chop = half + 1;
+			first += chop;
+			len   -= chop;
+		} else {
+			len = half;
+		}
+	}
+	assert(first == n || keys[first] >= k);
+	return first;
+}
+
+#endif
+
+#if !defined (__SSE4_2__) || !defined(NDEBUG)
+
+ZIX_PRIVATE size_t
+zix_trie_change_index_c(const uint8_t* a, const uint8_t* b, size_t len)
+{
+	for (size_t i = 0; i < len; ++i) {
+		if (a[i] != b[i]) {
+			return i;
+		}
+	}
+	return len;
+}
+
+#endif
+
+#ifdef __SSE4_2__
+
+ZIX_PRIVATE size_t
+zix_trie_change_index_sse(const uint8_t* a, const uint8_t* b, const size_t len)
+{
+	const size_t veclen = len & ~(sizeof(__m128i) - 1);
+	size_t       i      = 0;
+	for (; i < veclen; i += sizeof(__m128i)) {
+		const __m128i  r     = _mm_loadu_si128((const __m128i*)(a + i));
+		const __m128i  s     = _mm_loadu_si128((const __m128i*)(b + i));
+		const int      index = _mm_cmpistri(
+			r, s, _SIDD_SBYTE_OPS|_SIDD_CMP_EQUAL_EACH|_SIDD_NEGATIVE_POLARITY);
+
+		if (index != sizeof(__m128i)) {
+			assert(i + index == change_index_c(a, b, len));
+			return i + index;
+		}
+	}
+
+	const __m128i r     = _mm_loadu_si128((const __m128i*)(a + i));
+	const __m128i s     = _mm_loadu_si128((const __m128i*)(b + i));
+	const size_t  l     = len - i;
+	const int     index = _mm_cmpestri(
+		r, l, s, l,
+		_SIDD_SBYTE_OPS|_SIDD_CMP_EQUAL_EACH|_SIDD_MASKED_NEGATIVE_POLARITY);
+
+	assert(i + index == change_index_c(a, b, len));
+	return i + index;
+}
+
+#endif
+
+ZIX_PRIVATE size_t
+zix_trie_change_index(const uint8_t* a, const uint8_t* b, const size_t len)
+{
+#ifdef __SSE4_2__
+	return zix_trie_change_index_sse(a, b, len);
+#else
+	return zix_trie_change_index_c(a, b, len);
+#endif
+}
+
+#endif  /* ZIX_TRIE_UTIL_H */