[reference model] support multiple regions

This allows IF/WHILE serialization to use regions
instead of blocks to serialize nested regions.
For backward compatibility, both region and block
serialization are supported for IF/WHILE ops.

Signed-off-by: Tai Ly <tai.ly@arm.com>
Change-Id: Icf935561f9f5db38767ff76410bcd36896119395

3 files changed, 38 insertions, 12 deletions

diff --git a/reference_model/src/main.cpp b/reference_model/src/main.cpp
index 0375a48..ccc65f9 100644
--- a/reference_model/src/main.cpp
+++ b/reference_model/src/main.cpp
@@ -83,7 +83,7 @@ int main(int argc, char** argv)
         FATAL_ERROR("Unable to load graph");
     }
 
-    SubgraphTraverser main_gt(tsh.GetMainRegion()->GetBlockByName("main"), &tsh, nullptr);
+    SubgraphTraverser main_gt(tsh.GetMainRegion()->GetBlocks().front(), &tsh, nullptr);
 
     if (main_gt.initializeGraph())
     {
diff --git a/reference_model/src/ops/control_flow.cc b/reference_model/src/ops/control_flow.cc
index 942652d..f573d5b 100644
--- a/reference_model/src/ops/control_flow.cc
+++ b/reference_model/src/ops/control_flow.cc
@@ -181,10 +181,22 @@ int OpCondIf::checkTensorAttributes()
     cond = dynamic_cast<TosaReference::Tensor0<bool>*>(inputs[0]);
     ASSERT_MEM(cond);
 
-    auto region_name = getParentSGT()->getRegionName();
-    auto curr_region = tsh->GetRegionByName(region_name);
-    then_block = curr_region->GetBlockByName(attribute->then_branch());
-    else_block = curr_region->GetBlockByName(attribute->else_branch());
+    auto then_region = tsh->GetRegionByName(attribute->then_branch());
+    auto else_region = tsh->GetRegionByName(attribute->else_branch());
+    if (then_region && else_region)
+    {
+        // new serialization: then_branch and else_branch point to regions
+        then_block = then_region->GetBlocks().front();
+        else_block = else_region->GetBlocks().front();
+    }
+    else
+    {
+        // old serialization: then_branch and else_branch point to blocks in curr_region
+        auto region_name = getParentSGT()->getRegionName();
+        auto curr_region = tsh->GetRegionByName(region_name);
+        then_block       = curr_region->GetBlockByName(attribute->then_branch());
+        else_block       = curr_region->GetBlockByName(attribute->else_branch());
+    }
 
     ERROR_IF(!then_block, "OpCondIf: fail to resolve then_branch %s", attribute->then_branch().c_str());
 
@@ -309,10 +321,21 @@ int OpWhileLoop::checkTensorAttributes()
         return 1;
     }
 
-    auto region_name = getParentSGT()->getRegionName();
-    auto curr_region = tsh->GetRegionByName(region_name);
-    cond_block = curr_region->GetBlockByName(attribute->cond_branch());
-    body_block = curr_region->GetBlockByName(attribute->body_branch());
+    auto cond_region = tsh->GetRegionByName(attribute->cond_branch());
+    auto body_region = tsh->GetRegionByName(attribute->body_branch());
+    if (cond_region && body_region)
+    {
+        // new serialization: then_branch and else_branch point to regions
+        cond_block = cond_region->GetBlocks().front();
+        body_block = body_region->GetBlocks().front();
+    }
+    else
+    {
+        auto region_name = getParentSGT()->getRegionName();
+        auto curr_region = tsh->GetRegionByName(region_name);
+        cond_block       = curr_region->GetBlockByName(attribute->cond_branch());
+        body_block       = curr_region->GetBlockByName(attribute->body_branch());
+    }
 
     ERROR_IF(!cond_block, "OpWhileLoop: fail to resolve cond_branch %s", attribute->cond_branch().c_str());
     ERROR_IF(!body_block, "OpWhileLoop: fail to resolve body_branch %s", attribute->body_branch().c_str());
diff --git a/reference_model/src/subgraph_traverser.cc b/reference_model/src/subgraph_traverser.cc
index 8867ada..e7641ba 100644
--- a/reference_model/src/subgraph_traverser.cc
+++ b/reference_model/src/subgraph_traverser.cc
@@ -123,11 +123,14 @@ int SubgraphTraverser::initializeGraph()
 
     std::vector<TosaSerializationTensor*> ser_tensor_vec;
     // Get all the serialized tensors from TosaSerializationHandler.
-    for (auto block: tsh->GetMainRegion()->GetBlocks())
+    for (auto region : tsh->GetRegions())
     {
-        for (auto ser_tensor : block->GetTensors())
+        for (auto block : region->GetBlocks())
         {
-            ser_tensor_vec.push_back(ser_tensor);
+            for (auto ser_tensor : block->GetTensors())
+            {
+                ser_tensor_vec.push_back(ser_tensor);
+            }
         }
     }