Initial commit of Hyperscan

src/util/pack_bits.h

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+/*
+ * Copyright (c) 2015, Intel Corporation
+ *
+ * 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.
+ *  * Neither the name of Intel Corporation nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * 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.
+ */
+
+/** \file
+ * \brief Functions for packing/unpacking arrays.
+ */
+
+#ifndef UTIL_PACK_BITS_H
+#define UTIL_PACK_BITS_H
+
+#include "ue2common.h"
+#include "unaligned.h"
+#include "partial_store.h"
+
+/**
+ * \brief Pack bits from an array of 32-bit words into \a out.
+ *
+ * \param out Output array. Must be large enough to store sum(bits).
+ * \param v Input array.
+ * \param bits Number of low bits in the corresponding element of \a v to pack.
+ * \param elements Size of the \a v and \a bits arrays.
+ */
+static really_inline
+void pack_bits_32(char *out, const u32 *v, const u32 *bits,
+                  const unsigned int elements);
+
+/**
+ * \brief Pack bits from an array of 64-bit words into \a out.
+ *
+ * \param out Output array. Must be large enough to store sum(bits).
+ * \param v Input array.
+ * \param bits Number of low bits in the corresponding element of \a v to pack.
+ * \param elements Size of the \a v and \a bits arrays.
+ */
+static really_inline
+void pack_bits_64(char *out, const u64a *v, const u32 *bits,
+                  const unsigned int elements);
+
+/**
+ * \brief Unpack bits into an array of 32-bit words according to the counts
+ * given.
+ *
+ * \param v Output array.
+ * \param in Packed input array.
+ * \param bits Number of bits to unpack into the corresponding element of \a v.
+ * \param elements Size of the \a v and \a bits arrays.
+ */
+static really_inline
+void unpack_bits_32(u32 *v, const u8 *in, const u32 *bits,
+                    const unsigned int elements);
+
+/**
+ * \brief Unpack bits into an array of 64-bit words according to the counts
+ * given.
+ *
+ * \param v Output array.
+ * \param in Packed input array.
+ * \param bits Number of bits to unpack into the corresponding element of \a v.
+ * \param elements Size of the \a v and \a bits arrays.
+ */
+static really_inline
+void unpack_bits_64(u64a *v, const u8 *in, const u32 *bits,
+                    const unsigned int elements);
+
+/*
+ * Inline implementations follow.
+ */
+
+static really_inline
+void pack_bits_32(char *out, const u32 *v, const u32 *bits,
+                     const unsigned int elements) {
+    u32 write = 0; // accumulator
+    u32 idx = 0;   // acc holds this many bits
+
+    for (unsigned int i = 0; i < elements; i++) {
+        assert(bits[i] <= 32);
+        write |= (v[i] << idx);
+        idx += bits[i];
+        if (idx >= 32) {
+            unaligned_store_u32(out, write);
+            out += 4;
+            idx -= 32;
+            u32 leftover = bits[i] - idx;
+            if (leftover == 32) {
+                write = 0;
+            } else {
+                assert(leftover < 32);
+                write = v[i] >> leftover;
+            }
+        }
+    }
+
+    // There might be a write left over.
+    partial_store_u32(out, write, (idx + 7) / 8);
+}
+
+static really_inline
+void pack_bits_64(char *out, const u64a *v, const u32 *bits,
+                     const unsigned int elements) {
+    u64a write = 0; // accumulator
+    u32 idx = 0;    // acc holds this many bits
+
+    for (unsigned int i = 0; i < elements; i++) {
+        assert(bits[i] <= 64);
+        write |= (v[i] << idx);
+        idx += bits[i];
+        if (idx >= 64) {
+            unaligned_store_u64a(out, write);
+            out += 8;
+            idx -= 64;
+            u32 leftover = bits[i] - idx;
+            if (leftover == 64) {
+                write = 0;
+            } else {
+                assert(leftover < 64);
+                write = v[i] >> leftover;
+            }
+        }
+    }
+
+    // There might be a write left over.
+    DEBUG_PRINTF("partial store of idx=%u\n", idx);
+    partial_store_u64a(out, write, (idx + 7) / 8);
+}
+
+static really_inline
+void unpack_bits_32(u32 *v, const u8 *in, const u32 *bits,
+                   const unsigned int elements) {
+    u32 used = 0; // bits used from *in
+
+    for (unsigned int i = 0; i < elements; i++) {
+        assert(bits[i] <= 32);
+        u32 v_out = 0;   // accumulator for v[i]
+        u32 b = bits[i]; // bits left to read for v[i]
+        u32 vidx = 0;    // bits written to v[i]
+
+        while (b) {
+            u32 read = *in >> used;
+            u32 bits_read = 8 - used;
+
+            if (b <= bits_read) {
+                u32 mask = read & ((1U << b) - 1);
+                v_out |= mask << vidx;
+                vidx += b;
+                used += b;
+                b = 0;
+                if (used < 8) {
+                    continue; // more from this *in
+                }
+            } else {
+                v_out |= read << vidx;
+                vidx += bits_read;
+                b -= bits_read;
+            }
+
+            used = 0;
+            in++;
+        }
+
+        v[i] = v_out;
+    }
+}
+
+static really_inline
+void unpack_bits_64(u64a *v, const u8 *in, const u32 *bits,
+                    const unsigned int elements) {
+    u32 used = 0; // bits used from *in
+
+    for (unsigned int i = 0; i < elements; i++) {
+        assert(bits[i] <= 64);
+        u64a v_out = 0;  // accumulator for v[i]
+        u32 b = bits[i]; // bits left to read for v[i]
+        u32 vidx = 0;    // bits written to v[i]
+
+        while (b) {
+            u64a read = *in >> used;
+            u32 bits_read = 8 - used;
+
+            if (b <= bits_read) {
+                u64a mask = read & ((1U << b) - 1);
+                v_out |= mask << vidx;
+                vidx += b;
+                used += b;
+                b = 0;
+                if (used < 8) {
+                    continue; // more from this *in
+                }
+            } else {
+                v_out |= read << vidx;
+                vidx += bits_read;
+                b -= bits_read;
+            }
+
+            used = 0;
+            in++;
+        }
+
+        v[i] = v_out;
+    }
+}
+
+#endif // UTIL_PACK_BITS_H