1 files changed, 306 insertions, 0 deletions
diff --git a/compiler/enco/core/src/CppGen/Host.cpp b/compiler/enco/core/src/CppGen/Host.cpp
new file mode 100644
index 000000000..37e0583d7
--- /dev/null
+++ b/compiler/enco/core/src/CppGen/Host.cpp
@@ -0,0 +1,306 @@
+/*
+ * Copyright (c) 2018 Samsung Electronics Co., Ltd. All Rights Reserved
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "Host.h"
+
+#include <pp/EnclosedDocument.h>
+
+#include <stdex/Memory.h>
+
+#include <map>
+#include <string>
+
+namespace
+{
+
+/**
+ * @brief Data transfer between flat arrays
+ *
+ * Transfer(from, into) denotes the following C code:
+ *   dst[into] = src[from];
+ */
+class Transfer
+{
+public:
+  Transfer(uint32_t from, uint32_t into) : _from{from}, _into{into}
+  {
+    // DO NOTHING
+  }
+
+public:
+  uint32_t from(void) const { return _from; }
+  uint32_t into(void) const { return _into; }
+
+private:
+  uint32_t _from;
+  uint32_t _into;
+};
+
+using TransferSequence = std::vector<Transfer>;
+
+/**
+ * @brief Convert Shuffle instruction as a sequence of data transfer
+ */
+TransferSequence as_transfer_sequence(const coco::Shuffle *shuffle)
+{
+  TransferSequence seq;
+
+  for (const auto &dst : shuffle->range())
+  {
+    const auto src = shuffle->at(dst);
+    seq.emplace_back(src.value(), dst.value());
+  }
+
+  return seq;
+}
+
+/**
+ * Given a sequence of N data transfers,
+ * find_loop tries to compute count, src_step, dst_step that satisfies
+ * the following properties:
+ *
+ * First, N should be a multiple of count.
+ *        Below we refer to that multiplier as 'window' (= N / count)
+ *
+ * Second,
+ *   for all n in [0, count),
+ *     for all k in [0, window),
+ *       from[n * window + k] == from[k] + src_step, and
+ *       into[n * window + k] == into[k] + dst_step
+ */
+bool find_loop(TransferSequence::const_iterator beg, TransferSequence::const_iterator end,
+               uint32_t *p_count, uint32_t *p_src_step, uint32_t *p_dst_step)
+{
+  assert(p_count != nullptr);
+  assert(p_src_step != nullptr);
+  assert(p_dst_step != nullptr);
+
+  const uint32_t size = end - beg;
+
+  for (uint32_t window = 1; window <= size; ++window)
+  {
+    if (size % window != 0)
+    {
+      continue;
+    }
+
+    auto src_step_at = [&beg, window](uint32_t n) {
+      return (beg + n)->from() - (beg + n - window)->from();
+    };
+
+    auto dst_step_at = [&beg, window](uint32_t n) {
+      return (beg + n)->into() - (beg + n - window)->into();
+    };
+
+    const uint32_t count = size / window;
+    const uint32_t src_step = src_step_at(window);
+    const uint32_t dst_step = dst_step_at(window);
+
+    bool consistent = true;
+
+    for (uint32_t n = window + 1; n < size; ++n)
+    {
+      if ((src_step_at(n) != src_step) || (dst_step_at(n) != dst_step))
+      {
+        consistent = false;
+        break;
+      }
+    }
+
+    if (consistent)
+    {
+      *p_count = count;
+      *p_src_step = src_step;
+      *p_dst_step = dst_step;
+      return true;
+    }
+  }
+
+  return false;
+}
+
+/**
+ * @brief Single transfer loop (a triple of count, source step, detination step)
+ */
+class TransferLoop
+{
+public:
+  class Step
+  {
+  public:
+    Step(uint32_t src, uint32_t dst) : _src{src}, _dst{dst}
+    {
+      // DO NOTHING
+    }
+
+  public:
+    uint32_t src(void) const { return _src; }
+    uint32_t dst(void) const { return _dst; }
+
+  private:
+    uint32_t _src;
+    uint32_t _dst;
+  };
+
+public:
+  TransferLoop(uint32_t count, uint32_t src_step, uint32_t dst_step)
+      : _count{count}, _step{src_step, dst_step}
+  {
+    // DO NOTHING
+  }
+
+public:
+  uint32_t count(void) const { return _count; }
+  const Step &step(void) const { return _step; }
+
+private:
+  uint32_t _count;
+  Step _step;
+};
+
+/**
+ * @brief Nested transfer loops
+ */
+using TransferNest = std::vector<TransferLoop>;
+
+/**
+ * @brief Construct nested transfer loop-nest that correponds to a given Shuffle instruction
+ */
+TransferNest as_nest(const TransferSequence &seq)
+{
+  TransferNest nest;
+
+  auto beg = seq.begin();
+  auto end = seq.end();
+
+  uint32_t window = end - beg;
+  uint32_t count = 0;
+  uint32_t src_step = 0;
+  uint32_t dst_step = 0;
+
+  while ((window > 1) && find_loop(beg, end, &count, &src_step, &dst_step))
+  {
+    assert(window % count == 0);
+
+    window /= count;
+    end = beg + window;
+
+    nest.emplace_back(count, src_step, dst_step);
+  }
+
+  return nest;
+};
+
+uint32_t loop_count(const TransferNest &nest)
+{
+  uint32_t count = 1;
+
+  for (const auto &loop : nest)
+  {
+    count *= loop.count();
+  }
+
+  return count;
+};
+
+class InstrPrinter : public coco::Instr::Visitor<pp::LinearDocument>
+{
+public:
+  InstrPrinter(const enco::MemoryContext &mem) : _mem(mem)
+  {
+    // DO NOTHING
+  }
+
+private:
+  pp::LinearDocument visit(const coco::Shuffle *shuffle) override
+  {
+    auto from = shuffle->from();
+    auto into = shuffle->into();
+
+    //
+    // Analyze 'Shuffle' pattern, and convert it as nested loops
+    //
+    auto tseq = as_transfer_sequence(shuffle);
+    auto nest = as_nest(tseq);
+    assert(tseq.size() % loop_count(nest) == 0);
+    uint32_t window = tseq.size() / loop_count(nest);
+
+    //
+    // Generate loop body
+    //
+    pp::EnclosedDocument loop_body;
+
+    auto var_at = [](uint32_t lv) { return pp::fmt("_", lv); };
+
+    for (uint32_t lv = 0; lv < nest.size(); ++lv)
+    {
+      auto var = var_at(lv);
+
+      loop_body.front().append("for (uint32_t ", var, " = 0; ", var, " < ", nest.at(lv).count(),
+                               "; ++", var, ") {");
+      loop_body.front().indent();
+
+      loop_body.back().append("}");
+      loop_body.back().indent();
+    }
+
+    std::string src_index = "0";
+    std::string dst_index = "0";
+
+    for (uint32_t lv = 0; lv < nest.size(); ++lv)
+    {
+      src_index += pp::fmt(" + ", nest.at(lv).step().src(), " * ", var_at(lv));
+      dst_index += pp::fmt(" + ", nest.at(lv).step().dst(), " * ", var_at(lv));
+    }
+
+    for (uint32_t n = 0; n < window; ++n)
+    {
+      const auto src_base = pp::fmt("reinterpret_cast<const float *>(", _mem.base(from), ")");
+      const auto dst_base = pp::fmt("reinterpret_cast<float *>(", _mem.base(into), ")");
+
+      loop_body.front().append(dst_base, "[", dst_index, " + ", tseq.at(n).into(), "] = ", src_base,
+                               "[", src_index, " + ", tseq.at(n).from(), "];");
+    }
+
+    pp::LinearDocument res;
+    res.append(loop_body);
+    return res;
+  }
+
+private:
+  const enco::MemoryContext &_mem;
+};
+
+} // namespace
+
+namespace enco
+{
+
+std::unique_ptr<pp::MultiLineText> HostBlockCompiler::compile(const coco::Block *blk) const
+{
+  InstrPrinter prn{_mem};
+
+  auto res = stdex::make_unique<pp::LinearDocument>();
+
+  for (auto ins = blk->instr()->head(); ins; ins = ins->next())
+  {
+    res->append(ins->accept(prn));
+  }
+
+  return std::move(res);
+}
+
+} // namespace enco