--- /dev/null
+#include <algorithm>
+#include <assert.h>
+#include <endian.h>
+#include <limits.h>
+#include <stdint.h>
+#include <string.h>
+
+#if defined(__i386__) || defined(__x86_64__)
+#define COULD_HAVE_SSE2
+#include <immintrin.h>
+#endif
+
+#include "turbopfor-common.h"
+
+#define dprintf(...)
+//#define dprintf(...) fprintf(stderr, __VA_ARGS__);
+
+// Forward declarations to declare to the template code below that they exist.
+// (These must seemingly be non-templates for function multiversioning to work.)
+__attribute__((target("default")))
+const unsigned char *
+decode_for_interleaved_128_32(const unsigned char *in, uint32_t *out);
+__attribute__((target("default")))
+const unsigned char *
+decode_pfor_bitmap_interleaved_128_32(const unsigned char *in, uint32_t *out);
+__attribute__((target("default")))
+const unsigned char *
+decode_pfor_vb_interleaved_128_32(const unsigned char *in, uint32_t *out);
+
+#ifdef COULD_HAVE_SSE2
+__attribute__((target("sse2")))
+const unsigned char *
+decode_for_interleaved_128_32(const unsigned char *in, uint32_t *out);
+__attribute__((target("sse2")))
+const unsigned char *
+decode_pfor_bitmap_interleaved_128_32(const unsigned char *in, uint32_t *out);
+__attribute__((target("sse2")))
+const unsigned char *
+decode_pfor_vb_interleaved_128_32(const unsigned char *in, uint32_t *out);
+#endif
+
+template<class Docid>
+Docid read_le(const void *in)
+{
+ Docid val;
+ memcpy(&val, in, sizeof(val));
+ if constexpr (sizeof(Docid) == 8) {
+ return le64toh(val);
+ } else if constexpr (sizeof(Docid) == 4) {
+ return le32toh(val);
+ } else if constexpr (sizeof(Docid) == 2) {
+ return le16toh(val);
+ } else if constexpr (sizeof(Docid) == 1) {
+ return val;
+ } else {
+ assert(false);
+ }
+}
+
+// Reads a single value with an encoding that looks a bit like PrefixVarint.
+// It's unclear why this doesn't use the varbyte encoding.
+template<class Docid>
+const unsigned char *read_baseval(const unsigned char *in, Docid *out)
+{
+ //fprintf(stderr, "baseval: 0x%02x 0x%02x 0x%02x 0x%02x\n", in[0], in[1], in[2], in[3]);
+ if (*in < 128) {
+ *out = *in;
+ return in + 1;
+ } else if (*in < 192) {
+ *out = ((uint32_t(in[0]) << 8) | uint32_t(in[1])) & 0x3fff;
+ return in + 2;
+ } else if (*in < 224) {
+ *out = ((uint32_t(in[0]) << 16) |
+ (uint32_t(in[2]) << 8) |
+ (uint32_t(in[1]))) & 0x1fffff;
+ return in + 3;
+ } else {
+ assert(false); // Not implemented.
+ }
+}
+
+// Does not read past the end of the input.
+template<class Docid>
+const unsigned char *read_vb(const unsigned char *in, Docid *out)
+{
+ if (*in <= 176) {
+ *out = *in;
+ return in + 1;
+ } else if (*in <= 240) {
+ *out = ((uint32_t(in[0] - 177) << 8) | uint32_t(in[1])) + 177;
+ return in + 2;
+ } else if (*in <= 248) {
+ *out = ((uint32_t(in[0] - 241) << 16) | read_le<uint16_t>(in + 1)) + 16561;
+ return in + 3;
+ } else if (*in == 249) {
+ *out = (uint32_t(in[1])) |
+ (uint32_t(in[2]) << 8) |
+ (uint32_t(in[3]) << 16);
+ return in + 4;
+ } else if (*in == 250) {
+ *out = read_le<uint32_t>(in + 1);
+ return in + 5;
+ } else {
+ assert(false);
+ }
+}
+
+struct BitReader {
+public:
+ BitReader(const unsigned char *in, unsigned bits)
+ : in(in), bits(bits), mask(mask_for_bits(bits)) {}
+
+ // Can read 4 bytes past the end of the input (if bits_used == 0).
+ uint32_t read()
+ {
+ uint32_t val = (read_le<uint32_t>(in) >> bits_used) & mask;
+
+ bits_used += bits;
+ in += bits_used / 8;
+ bits_used %= 8;
+
+ return val;
+ }
+
+private:
+ const unsigned char *in;
+ const unsigned bits;
+ const unsigned mask;
+ unsigned bits_used = 0;
+};
+
+template<unsigned NumStreams>
+struct InterleavedBitReader {
+public:
+ InterleavedBitReader(const unsigned char *in, unsigned bits)
+ : in(in), bits(bits), mask(mask_for_bits(bits)) {}
+
+ // Can read 4 bytes past the end of the input (if bit_width == 0).
+ uint32_t read()
+ {
+ uint32_t val;
+ if (bits_used + bits > 32) {
+ val = (read_le<uint32_t>(in) >> bits_used) | (read_le<uint32_t>(in + Stride) << (32 - bits_used));
+ } else {
+ val = (read_le<uint32_t>(in) >> bits_used);
+ }
+
+ bits_used += bits;
+ in += Stride * (bits_used / 32);
+ bits_used %= 32;
+
+ return val & mask;
+ }
+
+private:
+ static constexpr unsigned Stride = NumStreams * sizeof(uint32_t);
+ const unsigned char *in;
+ const unsigned bits;
+ const unsigned mask;
+ unsigned bits_used = 0;
+};
+
+#ifdef COULD_HAVE_SSE2
+struct InterleavedBitReaderSSE2 {
+public:
+ __attribute__((target("sse2")))
+ InterleavedBitReaderSSE2(const unsigned char *in, unsigned bits)
+ : in(reinterpret_cast<const __m128i *>(in)), bits(bits), mask(_mm_set1_epi32(mask_for_bits(bits))) {}
+
+ // Can read 16 bytes past the end of the input (if bit_width == 0).
+ __attribute__((target("sse2")))
+ __m128i
+ read()
+ {
+ __m128i val = _mm_srli_epi32(_mm_loadu_si128(in), bits_used);
+ if (bits_used + bits > 32) {
+ __m128i val_upper = _mm_slli_epi32(_mm_loadu_si128(in + 1), 32 - bits_used);
+ val = _mm_or_si128(val, val_upper);
+ }
+ val = _mm_and_si128(val, mask);
+
+ bits_used += bits;
+ in += bits_used / 32;
+ bits_used %= 32;
+ return val;
+ }
+
+private:
+ const __m128i *in;
+ const unsigned bits;
+ const __m128i mask;
+ unsigned bits_used = 0;
+};
+#endif
+
+// Constant block. Layout:
+//
+// - Bit width (6 bits) | type << 6
+// - Base values (<bits> bits, rounded up to nearest byte)
+//
+// Can read 4 bytes past the end of the input (if bit_width == 0).
+template<class Docid>
+const unsigned char *decode_constant(const unsigned char *in, unsigned num, Docid *out)
+{
+ const unsigned bit_width = *in++ & 0x3f;
+ Docid val = read_le<Docid>(in);
+ if (bit_width < sizeof(Docid) * 8) {
+ val &= mask_for_bits(bit_width);
+ }
+
+ Docid prev_val = out[-1];
+ for (unsigned i = 0; i < num; ++i) {
+ out[i] = prev_val = val + prev_val + 1;
+ }
+ return in + div_round_up(bit_width, 8);
+}
+
+// FOR block (ie., PFor without exceptions). Layout:
+//
+// - Bit width (6 bits) | type << 6
+// - Base values (<num> values of <bits> bits, rounded up to a multiple of 32 values)
+//
+// Can read 4 bytes past the end of the input (inherit from BitReader).
+template<class Docid>
+const unsigned char *decode_for(const unsigned char *in, unsigned num, Docid *out)
+{
+ const unsigned bit_width = *in++ & 0x3f;
+
+ Docid prev_val = out[-1];
+ BitReader bs(in, bit_width);
+ for (unsigned i = 0; i < num; ++i) {
+ prev_val = out[i] = bs.read() + prev_val + 1;
+ }
+ return in + bytes_for_packed_bits(num, bit_width);
+}
+
+#ifdef COULD_HAVE_SSE2
+class DeltaDecoderSSE2 {
+public:
+ __attribute__((target("sse2")))
+ DeltaDecoderSSE2(uint32_t prev_val)
+ : prev_val(_mm_set1_epi32(prev_val)) {}
+
+ __attribute__((target("sse2")))
+ __m128i
+ decode(__m128i val)
+ {
+ val = _mm_add_epi32(val, _mm_slli_si128(val, 4));
+ val = _mm_add_epi32(val, _mm_slli_si128(val, 8));
+ val = _mm_add_epi32(val, _mm_add_epi32(prev_val, delta));
+ prev_val = _mm_shuffle_epi32(val, _MM_SHUFFLE(3, 3, 3, 3));
+ return val;
+ }
+
+private:
+ // Use 4/3/2/1 as delta instead of fixed 1, so that we can do the prev_val + delta
+ // in parallel with something else.
+ const __m128i delta = _mm_set_epi32(4, 3, 2, 1);
+
+ __m128i prev_val;
+};
+
+template<unsigned BlockSize>
+__attribute__((target("sse2"))) inline void delta_decode_sse2(uint32_t *out)
+{
+ DeltaDecoderSSE2 delta(out[-1]);
+ __m128i *outvec = reinterpret_cast<__m128i *>(out);
+ for (unsigned i = 0; i < BlockSize / 4; ++i) {
+ __m128i val = _mm_loadu_si128(outvec + i);
+ _mm_storeu_si128(outvec + i, delta.decode(val));
+ }
+}
+
+// Can read 16 bytes past the end of its input (inherit from InterleavedBitReaderSSE2).
+template<unsigned BlockSize, bool OrWithExisting, bool DeltaDecode, unsigned bit_width>
+__attribute__((target("sse2")))
+const unsigned char *
+decode_bitmap_sse2_unrolled(const unsigned char *in, uint32_t *out)
+{
+ __m128i *outvec = reinterpret_cast<__m128i *>(out);
+ DeltaDecoderSSE2 delta(out[-1]);
+ InterleavedBitReaderSSE2 bs(in, bit_width);
+#pragma GCC unroll 32
+ for (unsigned i = 0; i < BlockSize / 4; ++i) {
+ __m128i val = bs.read();
+ if constexpr (OrWithExisting) {
+ val = _mm_or_si128(val, _mm_slli_epi32(_mm_loadu_si128(outvec + i), bit_width));
+ }
+ if constexpr (DeltaDecode) {
+ val = delta.decode(val);
+ }
+ _mm_storeu_si128(outvec + i, val);
+ }
+ in += bytes_for_packed_bits(BlockSize, bit_width);
+ return in;
+}
+
+// Can read 16 bytes past the end of its input (inherit from InterleavedBitReaderSSE2).
+template<unsigned BlockSize, bool OrWithExisting, bool DeltaDecode>
+__attribute__((target("sse2")))
+const unsigned char *
+decode_bitmap_sse2(const unsigned char *in, unsigned bit_width, uint32_t *out)
+{
+ switch (bit_width) {
+ case 0:
+ return decode_bitmap_sse2_unrolled<BlockSize, OrWithExisting, DeltaDecode, 0>(in, out);
+ case 1:
+ return decode_bitmap_sse2_unrolled<BlockSize, OrWithExisting, DeltaDecode, 1>(in, out);
+ case 2:
+ return decode_bitmap_sse2_unrolled<BlockSize, OrWithExisting, DeltaDecode, 2>(in, out);
+ case 3:
+ return decode_bitmap_sse2_unrolled<BlockSize, OrWithExisting, DeltaDecode, 3>(in, out);
+ case 4:
+ return decode_bitmap_sse2_unrolled<BlockSize, OrWithExisting, DeltaDecode, 4>(in, out);
+ case 5:
+ return decode_bitmap_sse2_unrolled<BlockSize, OrWithExisting, DeltaDecode, 5>(in, out);
+ case 6:
+ return decode_bitmap_sse2_unrolled<BlockSize, OrWithExisting, DeltaDecode, 6>(in, out);
+ case 7:
+ return decode_bitmap_sse2_unrolled<BlockSize, OrWithExisting, DeltaDecode, 7>(in, out);
+ case 8:
+ return decode_bitmap_sse2_unrolled<BlockSize, OrWithExisting, DeltaDecode, 8>(in, out);
+ case 9:
+ return decode_bitmap_sse2_unrolled<BlockSize, OrWithExisting, DeltaDecode, 9>(in, out);
+ case 10:
+ return decode_bitmap_sse2_unrolled<BlockSize, OrWithExisting, DeltaDecode, 10>(in, out);
+ case 11:
+ return decode_bitmap_sse2_unrolled<BlockSize, OrWithExisting, DeltaDecode, 11>(in, out);
+ case 12:
+ return decode_bitmap_sse2_unrolled<BlockSize, OrWithExisting, DeltaDecode, 12>(in, out);
+ case 13:
+ return decode_bitmap_sse2_unrolled<BlockSize, OrWithExisting, DeltaDecode, 13>(in, out);
+ case 14:
+ return decode_bitmap_sse2_unrolled<BlockSize, OrWithExisting, DeltaDecode, 14>(in, out);
+ case 15:
+ return decode_bitmap_sse2_unrolled<BlockSize, OrWithExisting, DeltaDecode, 15>(in, out);
+ case 16:
+ return decode_bitmap_sse2_unrolled<BlockSize, OrWithExisting, DeltaDecode, 16>(in, out);
+ case 17:
+ return decode_bitmap_sse2_unrolled<BlockSize, OrWithExisting, DeltaDecode, 17>(in, out);
+ case 18:
+ return decode_bitmap_sse2_unrolled<BlockSize, OrWithExisting, DeltaDecode, 18>(in, out);
+ case 19:
+ return decode_bitmap_sse2_unrolled<BlockSize, OrWithExisting, DeltaDecode, 19>(in, out);
+ case 20:
+ return decode_bitmap_sse2_unrolled<BlockSize, OrWithExisting, DeltaDecode, 20>(in, out);
+ case 21:
+ return decode_bitmap_sse2_unrolled<BlockSize, OrWithExisting, DeltaDecode, 21>(in, out);
+ case 22:
+ return decode_bitmap_sse2_unrolled<BlockSize, OrWithExisting, DeltaDecode, 22>(in, out);
+ case 23:
+ return decode_bitmap_sse2_unrolled<BlockSize, OrWithExisting, DeltaDecode, 23>(in, out);
+ case 24:
+ return decode_bitmap_sse2_unrolled<BlockSize, OrWithExisting, DeltaDecode, 24>(in, out);
+ case 25:
+ return decode_bitmap_sse2_unrolled<BlockSize, OrWithExisting, DeltaDecode, 25>(in, out);
+ case 26:
+ return decode_bitmap_sse2_unrolled<BlockSize, OrWithExisting, DeltaDecode, 26>(in, out);
+ case 27:
+ return decode_bitmap_sse2_unrolled<BlockSize, OrWithExisting, DeltaDecode, 27>(in, out);
+ case 28:
+ return decode_bitmap_sse2_unrolled<BlockSize, OrWithExisting, DeltaDecode, 28>(in, out);
+ case 29:
+ return decode_bitmap_sse2_unrolled<BlockSize, OrWithExisting, DeltaDecode, 29>(in, out);
+ case 30:
+ return decode_bitmap_sse2_unrolled<BlockSize, OrWithExisting, DeltaDecode, 30>(in, out);
+ case 31:
+ return decode_bitmap_sse2_unrolled<BlockSize, OrWithExisting, DeltaDecode, 31>(in, out);
+ case 32:
+ return decode_bitmap_sse2_unrolled<BlockSize, OrWithExisting, DeltaDecode, 32>(in, out);
+ }
+ assert(false);
+}
+#endif
+
+// Like decode_for(), but the values are organized in four independent streams,
+// for SIMD (presumably SSE2). Supports a whole block only.
+//
+// Can read 16 bytes past the end of its input (inherit from InterleavedBitReader).
+template<unsigned BlockSize, class Docid>
+const unsigned char *decode_for_interleaved_generic(const unsigned char *in, Docid *out)
+{
+ const unsigned bit_width = *in++ & 0x3f;
+
+ InterleavedBitReader<4> bs0(in + 0 * sizeof(uint32_t), bit_width);
+ InterleavedBitReader<4> bs1(in + 1 * sizeof(uint32_t), bit_width);
+ InterleavedBitReader<4> bs2(in + 2 * sizeof(uint32_t), bit_width);
+ InterleavedBitReader<4> bs3(in + 3 * sizeof(uint32_t), bit_width);
+ for (unsigned i = 0; i < BlockSize / 4; ++i) {
+ out[i * 4 + 0] = bs0.read();
+ out[i * 4 + 1] = bs1.read();
+ out[i * 4 + 2] = bs2.read();
+ out[i * 4 + 3] = bs3.read();
+ }
+ Docid prev_val = out[-1];
+ for (unsigned i = 0; i < BlockSize; ++i) {
+ out[i] = prev_val = out[i] + prev_val + 1;
+ }
+ return in + bytes_for_packed_bits(BlockSize, bit_width);
+}
+
+// Does not read past the end of the input.
+template<unsigned BlockSize, class Docid>
+const unsigned char *decode_for_interleaved(const unsigned char *in, Docid *out)
+{
+ if constexpr (BlockSize == 128 && sizeof(Docid) == sizeof(uint32_t)) {
+ return decode_for_interleaved_128_32(in, out);
+ } else {
+ return decode_for_interleaved_generic(in, out);
+ }
+}
+
+// Does not read past the end of the input.
+__attribute__((target("default")))
+const unsigned char *
+decode_for_interleaved_128_32(const unsigned char *in, uint32_t *out)
+{
+ return decode_for_interleaved_generic<128>(in, out);
+}
+
+#ifdef COULD_HAVE_SSE2
+// Specialized version for SSE2.
+// Can read 16 bytes past the end of the input (inherit from decode_bitmap_sse2()).
+__attribute__((target("sse2")))
+const unsigned char *
+decode_for_interleaved_128_32(const unsigned char *in, uint32_t *out)
+{
+ constexpr unsigned BlockSize = 128;
+
+ const unsigned bit_width = *in++ & 0x3f;
+
+ in = decode_bitmap_sse2<BlockSize, /*OrWithExisting=*/false, /*DeltaDecode=*/true>(in, bit_width, out);
+
+ return in;
+}
+#endif
+
+// Can read 4 bytes past the end of the input (inherit from BitReader).
+template<class Docid>
+const unsigned char *decode_pfor_bitmap_exceptions(const unsigned char *in, unsigned num, Docid *out)
+{
+ const unsigned exception_bit_width = *in++;
+ const uint64_t *exception_bitmap_ptr = reinterpret_cast<const uint64_t *>(in);
+ in += div_round_up(num, 8);
+
+ int num_exceptions = 0;
+
+ BitReader bs(in, exception_bit_width);
+ for (unsigned i = 0; i < num; i += 64, ++exception_bitmap_ptr) {
+ uint64_t exceptions = read_le<uint64_t>(exception_bitmap_ptr);
+ if (num - i < 64) {
+ // We've read some bytes past the end, so clear out the junk bits.
+ exceptions &= (1ULL << (num - i)) - 1;
+ }
+ for (; exceptions != 0; exceptions &= exceptions - 1, ++num_exceptions) {
+ unsigned idx = (ffsll(exceptions) - 1) + i;
+ out[idx] = bs.read();
+ }
+ }
+ in += bytes_for_packed_bits(num_exceptions, exception_bit_width);
+ return in;
+}
+
+// PFor block with bitmap exceptions. Layout:
+//
+// - Bit width (6 bits) | type << 6
+// - Exception bit width (8 bits)
+// - Bitmap of which values have exceptions (<num> bits, rounded up to a byte)
+// - Exceptions (<num_exc> values of <bits_exc> bits, rounded up to a byte)
+// - Base values (<num> values of <bits> bits, rounded up to a byte)
+//
+// Can read 4 bytes past the end of the input (inherit from BitReader).
+template<class Docid>
+const unsigned char *decode_pfor_bitmap(const unsigned char *in, unsigned num, Docid *out)
+{
+ memset(out, 0, num * sizeof(Docid));
+
+ const unsigned bit_width = *in++ & 0x3f;
+
+ in = decode_pfor_bitmap_exceptions(in, num, out);
+
+ // Decode the base values, and delta-decode.
+ Docid prev_val = out[-1];
+ BitReader bs(in, bit_width);
+ for (unsigned i = 0; i < num; ++i) {
+ out[i] = prev_val = ((out[i] << bit_width) | bs.read()) + prev_val + 1;
+ }
+ return in + bytes_for_packed_bits(num, bit_width);
+}
+
+// Like decode_pfor_bitmap(), but the base values are organized in four
+// independent streams, for SIMD (presumably SSE2). Supports a whole block only.
+//
+// Can read 16 bytes past the end of the input (inherit from InterleavedBitReader
+// and decode_pfor_bitmap_exceptions()).
+template<unsigned BlockSize, class Docid>
+const unsigned char *decode_pfor_bitmap_interleaved_generic(const unsigned char *in, Docid *out)
+{
+ memset(out, 0, BlockSize * sizeof(Docid));
+
+ const unsigned bit_width = *in++ & 0x3f;
+
+ in = decode_pfor_bitmap_exceptions(in, BlockSize, out);
+
+ // Decode the base values.
+ InterleavedBitReader<4> bs0(in + 0 * sizeof(uint32_t), bit_width);
+ InterleavedBitReader<4> bs1(in + 1 * sizeof(uint32_t), bit_width);
+ InterleavedBitReader<4> bs2(in + 2 * sizeof(uint32_t), bit_width);
+ InterleavedBitReader<4> bs3(in + 3 * sizeof(uint32_t), bit_width);
+ for (unsigned i = 0; i < BlockSize / 4; ++i) {
+ out[i * 4 + 0] = bs0.read() | (out[i * 4 + 0] << bit_width);
+ out[i * 4 + 1] = bs1.read() | (out[i * 4 + 1] << bit_width);
+ out[i * 4 + 2] = bs2.read() | (out[i * 4 + 2] << bit_width);
+ out[i * 4 + 3] = bs3.read() | (out[i * 4 + 3] << bit_width);
+ }
+
+ // Delta-decode.
+ Docid prev_val = out[-1];
+ for (unsigned i = 0; i < BlockSize; ++i) {
+ out[i] = prev_val = out[i] + prev_val + 1;
+ }
+ return in + bytes_for_packed_bits(BlockSize, bit_width);
+}
+
+// Can read 16 bytes past the end of the input (inherit from decode_pfor_bitmap_interleaved_generic()).
+template<unsigned BlockSize, class Docid>
+const unsigned char *decode_pfor_bitmap_interleaved(const unsigned char *in, Docid *out)
+{
+ if constexpr (BlockSize == 128 && sizeof(Docid) == sizeof(uint32_t)) {
+ return decode_pfor_bitmap_interleaved_128_32(in, out);
+ } else {
+ return decode_pfor_bitmap_interleaved_generic(in, out);
+ }
+}
+
+__attribute__((target("default")))
+const unsigned char *
+decode_pfor_bitmap_interleaved_128_32(const unsigned char *in, uint32_t *out)
+{
+ return decode_pfor_bitmap_interleaved_generic<128>(in, out);
+}
+
+#ifdef COULD_HAVE_SSE2
+// Specialized version for SSE2.
+//
+// Can read 16 bytes past the end of the input (inherit from InterleavedBitReaderSSE2
+// and decode_pfor_bitmap_exceptions()).
+__attribute__((target("sse2")))
+const unsigned char *
+decode_pfor_bitmap_interleaved_128_32(const unsigned char *in, uint32_t *out)
+{
+ constexpr unsigned BlockSize = 128;
+
+// Set all output values to zero, before the exceptions are filled in.
+#pragma GCC unroll 4
+ for (unsigned i = 0; i < BlockSize / 4; ++i) {
+ _mm_storeu_si128(reinterpret_cast<__m128i *>(out) + i, _mm_setzero_si128());
+ }
+
+ const unsigned bit_width = *in++ & 0x3f;
+
+ in = decode_pfor_bitmap_exceptions(in, BlockSize, out);
+ in = decode_bitmap_sse2<BlockSize, /*OrWithExisting=*/true, /*DeltaDecode=*/true>(in, bit_width, out);
+
+ return in;
+}
+#endif
+
+// PFor block with variable-byte exceptions. Layout:
+//
+// - Bit width (6 bits) | type << 6
+// - Number of exceptions (8 bits)
+// - Base values (<num> values of <bits> bits, rounded up to a byte)
+// - Exceptions:
+// - If first byte is 255, <num_exc> 32-bit values (does not include the 255 byte)
+// - Else, <num_exc> varbyte-encoded values (includes the non-255 byte)
+// - Indexes of exceptions (<num_exc> bytes).
+//
+// Can read 4 bytes past the end of the input (inherit from BitReader,
+// assuming zero exceptions).
+template<unsigned BlockSize, class Docid>
+const unsigned char *decode_pfor_vb(const unsigned char *in, unsigned num, Docid *out)
+{
+ //fprintf(stderr, "in=%p out=%p num=%u\n", in, out, num);
+
+ const unsigned bit_width = *in++ & 0x3f;
+ unsigned num_exceptions = *in++;
+
+ // Decode the base values.
+ BitReader bs(in, bit_width);
+ for (unsigned i = 0; i < num; ++i) {
+ out[i] = bs.read();
+ }
+ in += bytes_for_packed_bits(num, bit_width);
+
+ // Decode exceptions.
+ Docid exceptions[BlockSize];
+ if (*in == 255) {
+ ++in;
+ for (unsigned i = 0; i < num_exceptions; ++i) {
+ exceptions[i] = read_le<Docid>(in);
+ in += sizeof(Docid);
+ }
+ } else {
+ for (unsigned i = 0; i < num_exceptions; ++i) {
+ in = read_vb(in, &exceptions[i]);
+ }
+ }
+ // Apply exceptions.
+ for (unsigned i = 0; i < num_exceptions; ++i) {
+ unsigned idx = *in++;
+ out[idx] |= exceptions[i] << bit_width;
+ }
+
+ // Delta-decode.
+ Docid prev_val = out[-1];
+ for (unsigned i = 0; i < num; ++i) {
+ out[i] = prev_val = out[i] + prev_val + 1;
+ }
+
+ return in;
+}
+
+// Like decode_pfor_vb(), but the base values are organized in four
+// independent streams, for SIMD (presumably SSE2). Supports a whole block only.
+// Can read 16 bytes past the end of its input (inherit from InterleavedBitReader).
+template<unsigned BlockSize, class Docid>
+const unsigned char *decode_pfor_vb_interleaved_generic(const unsigned char *in, Docid *out)
+{
+ const unsigned bit_width = *in++ & 0x3f;
+ unsigned num_exceptions = *in++;
+
+ // Decode the base values.
+ InterleavedBitReader<4> bs0(in + 0 * sizeof(uint32_t), bit_width);
+ InterleavedBitReader<4> bs1(in + 1 * sizeof(uint32_t), bit_width);
+ InterleavedBitReader<4> bs2(in + 2 * sizeof(uint32_t), bit_width);
+ InterleavedBitReader<4> bs3(in + 3 * sizeof(uint32_t), bit_width);
+ for (unsigned i = 0; i < BlockSize / 4; ++i) {
+ out[i * 4 + 0] = bs0.read();
+ out[i * 4 + 1] = bs1.read();
+ out[i * 4 + 2] = bs2.read();
+ out[i * 4 + 3] = bs3.read();
+ }
+ in += bytes_for_packed_bits(BlockSize, bit_width);
+
+ // Decode exceptions.
+ Docid exceptions[BlockSize];
+ if (*in == 255) {
+ ++in;
+ for (unsigned i = 0; i < num_exceptions; ++i) {
+ exceptions[i] = read_le<Docid>(in);
+ in += sizeof(Docid);
+ }
+ } else {
+ for (unsigned i = 0; i < num_exceptions; ++i) {
+ in = read_vb(in, &exceptions[i]);
+ }
+ }
+
+ // Apply exceptions.
+ for (unsigned i = 0; i < num_exceptions; ++i) {
+ unsigned idx = *in++;
+ out[idx] |= exceptions[i] << bit_width;
+ }
+
+ // Delta-decode.
+ Docid prev_val = out[-1];
+ for (unsigned i = 0; i < BlockSize; ++i) {
+ out[i] = prev_val = out[i] + prev_val + 1;
+ }
+
+ return in;
+}
+
+// Can read 16 bytes past the end of its input (inherit from decode_pfor_vb_interleaved_generic()).
+template<unsigned BlockSize, class Docid>
+const unsigned char *decode_pfor_vb_interleaved(const unsigned char *in, Docid *out)
+{
+ if constexpr (BlockSize == 128 && sizeof(Docid) == sizeof(uint32_t)) {
+ return decode_pfor_vb_interleaved_128_32(in, out);
+ } else {
+ return decode_pfor_vb_interleaved_generic(in, out);
+ }
+}
+
+__attribute__((target("default")))
+const unsigned char *
+decode_pfor_vb_interleaved_128_32(const unsigned char *in, uint32_t *out)
+{
+ return decode_pfor_vb_interleaved_generic<128>(in, out);
+}
+
+// Specialized version for SSE2.
+// Can read 16 bytes past the end of the input (inherit from decode_bitmap_sse2()).
+__attribute__((target("sse2")))
+const unsigned char *
+decode_pfor_vb_interleaved_128_32(const unsigned char *in, uint32_t *out)
+{
+ constexpr unsigned BlockSize = 128;
+ using Docid = uint32_t;
+
+ const unsigned bit_width = *in++ & 0x3f;
+ unsigned num_exceptions = *in++;
+
+ // Decode the base values.
+ in = decode_bitmap_sse2<BlockSize, /*OrWithExisting=*/false, /*DeltaDecode=*/false>(in, bit_width, out);
+
+ // Decode exceptions.
+ Docid exceptions[BlockSize];
+ if (*in == 255) {
+ ++in;
+ for (unsigned i = 0; i < num_exceptions; ++i) {
+ exceptions[i] = read_le<Docid>(in);
+ in += sizeof(Docid);
+ }
+ } else {
+ for (unsigned i = 0; i < num_exceptions; ++i) {
+ in = read_vb(in, &exceptions[i]);
+ }
+ }
+
+ // Apply exceptions.
+ for (unsigned i = 0; i < num_exceptions; ++i) {
+ unsigned idx = *in++;
+ out[idx] |= exceptions[i] << bit_width;
+ }
+
+ delta_decode_sse2<BlockSize>(out);
+
+ return in;
+}
+
+// Can read 16 bytes past the end of the input (inherit from several functions).
+template<unsigned BlockSize, class Docid>
+const unsigned char *decode_pfor_delta1(const unsigned char *in, unsigned num, bool interleaved, Docid *out)
+{
+ if (num == 0) {
+ return in;
+ }
+ in = read_baseval(in, out++);
+
+ for (unsigned i = 1; i < num; i += BlockSize, out += BlockSize) {
+ const unsigned num_this_block = std::min<unsigned>(num - i, BlockSize);
+ switch (in[0] >> 6) {
+ case BlockType::FOR:
+ if (interleaved && num_this_block == BlockSize) {
+ dprintf("%d+%d: blocktype=%d (for, interleaved), bitwidth=%d\n", i, num_this_block, in[0] >> 6, in[0] & 0x3f);
+ in = decode_for_interleaved<BlockSize>(in, out);
+ } else {
+ dprintf("%d+%d: blocktype=%d (for), bitwidth=%d\n", i, num_this_block, in[0] >> 6, in[0] & 0x3f);
+ in = decode_for(in, num_this_block, out);
+ }
+ break;
+ case BlockType::PFOR_VB:
+ if (interleaved && num_this_block == BlockSize) {
+ dprintf("%d+%d: blocktype=%d (pfor + vb, interleaved), bitwidth=%d\n", i, num_this_block, in[0] >> 6, in[0] & 0x3f);
+ in = decode_pfor_vb_interleaved<BlockSize>(in, out);
+ } else {
+ dprintf("%d+%d: blocktype=%d (pfor + vb), bitwidth=%d\n", i, num_this_block, in[0] >> 6, in[0] & 0x3f);
+ in = decode_pfor_vb<BlockSize>(in, num_this_block, out);
+ }
+ break;
+ case BlockType::PFOR_BITMAP:
+ if (interleaved && num_this_block == BlockSize) {
+ dprintf("%d+%d: blocktype=%d (pfor + bitmap, interleaved), bitwidth=%d\n", i, num_this_block, in[0] >> 6, in[0] & 0x3f);
+ in = decode_pfor_bitmap_interleaved<BlockSize>(in, out);
+ } else {
+ dprintf("%d+%d: blocktype=%d (pfor + bitmap), bitwidth=%d\n", i, num_this_block, in[0] >> 6, in[0] & 0x3f);
+ in = decode_pfor_bitmap(in, num_this_block, out);
+ }
+ break;
+ case BlockType::CONSTANT:
+ dprintf("%d+%d: blocktype=%d (constant), bitwidth=%d\n", i, num_this_block, in[0] >> 6, in[0] & 0x3f);
+ in = decode_constant(in, num_this_block, out);
+ break;
+ }
+ }
+
+ return in;
+}
+
+const unsigned char *decode_pfor_delta1_128(const unsigned char *in, unsigned num, bool interleaved, uint32_t *out)
+{
+ return decode_pfor_delta1<128>(in, num, interleaved, out);
+}
projects / plocate / blobdiff