[enco] Support Shuffle code generation (#1182)

This commit implement Shuffle code generator which emits nested loops
that corresponds to a shuffle instruction.

Signed-off-by: Jonghyun Park <jh1302.park@samsung.com>

diff --git a/contrib/enco/core/src/CppCode.cpp b/contrib/enco/core/src/CppCode.cpp
index 0b689e8..dd38763 100644 (file)
--- a/contrib/enco/core/src/CppCode.cpp
+++ b/contrib/enco/core/src/CppCode.cpp
@@ -1,6 +1,9 @@
 #include "CppCode.h"
 
 #include "CppGen/Global.h"
+#include "CppGen/MemoryContext.h"
+
+#include "CppGen/Host.h"
 
 #include "Dims.h"
 
@@ -10,6 +13,16 @@
 #include <string>
 #include <stdexcept>
 
+namespace
+{
+
+struct InvokeFunction
+{
+  pp::LinearDocument body;
+};
+
+} // namespace
+
 namespace enco
 {
 
@@ -18,6 +31,46 @@ void CppCode::dump(std::ostream &os) const
   auto m = _code->module();
 
   Global global;
+  InvokeFunction invoke;
+
+  MemoryContext mem;
+
+  // Set dedicated memory region for network inputs
+  for (uint32_t n = 0; n < m->input()->size(); ++n)
+  {
+    mem.base(m->input()->at(n)->bag(), pp::fmt("net->inputs[", n, "].ptr"));
+    mem.size(m->input()->at(n)->bag(), pp::fmt("net->inputs[", n, "].len"));
+  }
+
+  // Set dedicated memory region for network outputs
+  for (uint32_t n = 0; n < m->output()->size(); ++n)
+  {
+    mem.base(m->output()->at(n)->bag(), pp::fmt("net->outputs[", n, "].ptr"));
+    mem.size(m->output()->at(n)->bag(), pp::fmt("net->outputs[", n, "].len"));
+  }
+
+  // Create Code Block Builder
+  HostBlockCompiler host_compiler{mem};
+
+  for (auto blk = m->block()->head(); blk; blk = blk->next())
+  {
+    invoke.body.append("{");
+    invoke.body.indent();
+
+    if (auto binder = _code->ann()->find(blk))
+    {
+      throw std::runtime_error{"NYI; Android NN codegen is not supported, yet"};
+    }
+    else
+    {
+      // Generate code on-the-fly for Android NN-incompatible blocks
+      auto lines = host_compiler.compile(blk);
+      invoke.body.append(*lines);
+    }
+
+    invoke.body.unindent();
+    invoke.body.append("}");
+  }
 
   //
   // Generate full C++ source code with code snippet
@@ -216,7 +269,7 @@ void CppCode::dump(std::ostream &os) const
 
   source.append("void ", name, "_invoke(", name, " *net) {");
   source.indent();
-  source.append("assert(\"NYI\");");
+  source.append(invoke.body);
   source.unindent();
   source.append("}");
 

diff --git a/contrib/enco/core/src/CppGen/Host.cpp b/contrib/enco/core/src/CppGen/Host.cpp
new file mode 100644 (file)
index 0000000..6115051
--- /dev/null
+++ b/contrib/enco/core/src/CppGen/Host.cpp
@@ -0,0 +1,289 @@
+#include "Host.h"
+
+#include <pp/EnclosedDocument.h>
+
+#include <nncc/foundation/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 (uint32_t n = 0; n < shuffle->into()->size(); ++n)
+  {
+    seq.emplace_back(shuffle->at(n).value(), n);
+  }
+
+  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 coco::Shuffle *shuffle)
+{
+  TransferNest nest;
+  TransferSequence seq = as_transfer_sequence(shuffle);
+
+  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::DefaultVisitor<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 nest = as_nest(shuffle);
+    assert(shuffle->into()->size() % loop_count(nest) == 0);
+    uint32_t window = shuffle->into()->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, " + ", n, "] = ", src_base, "[", src_index,
+                               " + ", shuffle->at(n).value(), "];");
+    }
+
+    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 = nncc::foundation::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

diff --git a/contrib/enco/core/src/CppGen/Host.h b/contrib/enco/core/src/CppGen/Host.h
new file mode 100644 (file)
index 0000000..826f4bf
--- /dev/null
+++ b/contrib/enco/core/src/CppGen/Host.h
@@ -0,0 +1,32 @@
+#ifndef __ENCO_CPP_GEN_HOST_H__
+#define __ENCO_CPP_GEN_HOST_H__
+
+#include "CppGen/MemoryContext.h"
+
+#include <coco/IR.h>
+#include <pp/MultiLineText.h>
+
+namespace enco
+{
+
+/***
+ * @brief Generate C++ code that does not depend on Anroid NN API
+ */
+class HostBlockCompiler
+{
+public:
+  HostBlockCompiler(const enco::MemoryContext &mem) : _mem(mem)
+  {
+    // DO NOTHING
+  }
+
+public:
+  std::unique_ptr<pp::MultiLineText> compile(const coco::Block *blk) const;
+
+private:
+  const enco::MemoryContext &_mem;
+};
+
+} // namespace enco
+
+#endif // __ENCO_CPP_GEN_HOST_H__