[code generation] bugfix in single buffering

lib/codegen/liveness.cpp

@@ -11,30 +11,43 @@ namespace codegen{
 
 
 // Entry point
-void liveness::run(ir::module &mod) {
-for(ir::function *fn: mod.get_function_list()){
-  // Assigns index to each instruction
-  slot_index index = 0;
-  for(ir::basic_block *block: fn->blocks())
-  for(ir::instruction *instr: block->get_inst_list()){
-    index += 1;
-    indices_.insert({instr, index});
-  }
-  // Liveness analysis
-  // Creates live intervals
-  for(auto i: indices_){
-    ir::value *v = i.first;
-    if(!info_->is_shared(v) || info_->get_reference(v))
-      continue;
-    unsigned start = i.second;
-    unsigned end = start;
-    for(ir::value *u: v->get_users()){
-      start = std::min(start, indices_.at(u));
-      end = std::max(end, indices_.at(u));
-    }
-    intervals_[v] = segment{start, end};
+inline bool is_shared(ir::value* v) {
+  if(auto x = dynamic_cast<ir::copy_to_shared_inst*>(v))
+    return true;
+  if(auto x = dynamic_cast<ir::phi_node*>(v)){
+    bool res = true;
+    for(unsigned inc = 0; inc < x->get_num_incoming(); inc++)
+      res = res && is_shared(x->get_incoming_value(inc));
+    return res;
   }
+  return false;
 }
+
+void liveness::run(ir::module &mod) {
+  for(ir::function *fn: mod.get_function_list()){
+    // Assigns index to each instruction
+    slot_index index = 0;
+    for(ir::basic_block *block: fn->blocks())
+    for(ir::instruction *instr: block->get_inst_list()){
+      index += 1;
+      indices_.insert({instr, index});
+    }
+    // Liveness analysis
+    // Creates live intervals
+    for(auto i: indices_){
+      ir::value *v = i.first;
+      if(!info_->is_shared(v) || info_->get_reference(v))
+        continue;
+      unsigned start = i.second;
+      unsigned end = start;
+      for(ir::value *u: v->get_users()){
+        start = std::min(start, indices_.at(u));
+        end = std::max(end, indices_.at(u));
+      }
+      intervals_[v] = segment{start, end};
+    }
+    std::cout << "Number of intervals: " << intervals_.size() << std::endl;
+  }
 }
 
 }