From 4029ae66af6a4d9be9429dcb3a612d0899d5b2ce Mon Sep 17 00:00:00 2001
From: =?utf8?q?=EB=B0=95=EC=A2=85=ED=98=84/=EB=8F=99=EC=9E=91=EC=A0=9C?=
 =?utf8?q?=EC=96=B4Lab=28SR=29/Staff=20Engineer/=EC=82=BC=EC=84=B1?=
 =?utf8?q?=EC=A0=84=EC=9E=90?= <jh1302.park@samsung.com>
Date: Tue, 23 Oct 2018 14:14:16 +0900
Subject: [PATCH] [enco] Enumerate host allocation correctly (#1942)

The current implementation("intermediates") cannot enumerate a bag
as a host allocation if this bag is shared by multiple ANN subnet,
but not accessed by host (ANN-incompatible) block.

Signed-off-by: Jonghyun Park <jh1302.park@samsung.com>
---
 contrib/enco/core/src/CppCode.cpp | 75 ++++++++++++++++++++++++++++++++++++++-
 1 file changed, 74 insertions(+), 1 deletion(-)

diff --git a/contrib/enco/core/src/CppCode.cpp b/contrib/enco/core/src/CppCode.cpp
index 7ef0cb8..db24a3a 100644
--- a/contrib/enco/core/src/CppCode.cpp
+++ b/contrib/enco/core/src/CppCode.cpp
@@ -66,6 +66,79 @@ private:
   uint32_t _var_count = 0;
 };
 
+/**
+ * @brief Enumerate a set of Bag accessed by a given instruction
+ *
+ * Supported instruction:
+ *    "Shuffle"
+ */
+class AccessedBagAccumulator : public coco::Instr::Visitor<void>
+{
+public:
+  AccessedBagAccumulator(std::set<coco::Bag *> *out) : _out{out}
+  {
+    // Validate "out"
+    assert(_out != nullptr);
+  }
+
+public:
+  void visit(const coco::Shuffle *shuffle) override
+  {
+    assert(shuffle->from() != nullptr);
+    assert(shuffle->into() != nullptr);
+
+    _out->insert(shuffle->from());
+    _out->insert(shuffle->into());
+  }
+
+private:
+  std::set<coco::Bag *> *_out;
+};
+
+/**
+ * @brief Return a set of bags that SHOULD have a host allocation
+ */
+std::set<coco::Bag *> hosted(const enco::Code *code)
+{
+  std::set<coco::Bag *> res;
+
+  auto m = code->module();
+  auto ann_ctx = enco::SubnetManager::context(m);
+
+  for (auto blk = m->block()->head(); blk; blk = blk->next())
+  {
+    if (auto ann_binder = ann_ctx->find(blk))
+    {
+      // Case: The current block is ANN-compatible
+
+      // Each ANN input SHOULD have a corresponding host allocation
+      for (uint32_t n = 0; n < ann_binder->module()->input()->size(); ++n)
+      {
+        res.insert(ann_binder->input(n));
+      }
+
+      // Each ANN output SHOULD have a corresponding host allocation
+      for (uint32_t n = 0; n < ann_binder->module()->output()->size(); ++n)
+      {
+        res.insert(ann_binder->output(n));
+      }
+    }
+    else
+    {
+      // Every bag that ANN-incompatible block accesses SHOULD have a corresponding host allocation
+      AccessedBagAccumulator acc{&res};
+
+      for (auto ins = blk->instr()->head(); ins; ins = ins->next())
+      {
+        ins->accept(acc);
+      }
+    }
+  }
+
+  return res;
+}
+
+// WARN Deprecated
 /** @brief Return a set of Bag to be allocated */
 // NOTE An input/output bag may be included in the retrun set of "intermediates"
 std::set<coco::Bag *> intermediates(const enco::Code *code)
@@ -244,7 +317,7 @@ void CppCode::dump(std::ostream &os) const
   }
 
   // Set dedicated memory reigion for intermediate buffer(s)
-  for (const auto &bag : intermediates(_code))
+  for (const auto &bag : hosted(_code))
   {
     // Skip if a bag is already allocated
     if (mem.member(bag))
-- 
2.7.4