From 12ef1583114dfdc99cd39e1266c4d0ad286882d0 Mon Sep 17 00:00:00 2001
From: Abdul Zreika <azre6702@uni.sydney.edu.au>
Date: Wed, 18 Nov 2020 17:55:35 +1100
Subject: [PATCH] Standardised scc code-gen.

---
 src/ast2ram/AstToRamTranslator.cpp | 23 +++++++++++++----------
 src/ast2ram/AstToRamTranslator.h   |  2 +-
 2 files changed, 14 insertions(+), 11 deletions(-)

diff --git a/src/ast2ram/AstToRamTranslator.cpp b/src/ast2ram/AstToRamTranslator.cpp
index db7f9e49c8f..0f4f2eb1365 100644
--- a/src/ast2ram/AstToRamTranslator.cpp
+++ b/src/ast2ram/AstToRamTranslator.cpp
@@ -251,8 +251,8 @@ Own<ram::Statement> AstToRamTranslator::generateNonRecursiveRelation(const ast::
     return mk<ram::Sequence>(std::move(result));
 }
 
-Own<ram::Statement> AstToRamTranslator::generateStratum(size_t scc, size_t idx) const {
-    // make a new ram statement for the current SCC
+Own<ram::Statement> AstToRamTranslator::generateStratum(size_t scc) const {
+    // Make a new ram statement for the current SCC
     VecOwn<ram::Statement> current;
 
     // load all internal input relations from the facts dir with a .facts extension
@@ -261,7 +261,7 @@ Own<ram::Statement> AstToRamTranslator::generateStratum(size_t scc, size_t idx)
         appendStmt(current, generateLoadRelation(relation));
     }
 
-    // compute the current stratum
+    // Compute the current stratum
     const auto& isRecursive = sccGraph->isRecursive(scc);
     const auto& sccRelations = sccGraph->getInternalRelations(scc);
     if (isRecursive) {
@@ -272,16 +272,12 @@ Own<ram::Statement> AstToRamTranslator::generateStratum(size_t scc, size_t idx)
         appendStmt(current, generateNonRecursiveRelation(*relation));
     }
 
-    // store all internal output relations to the output dir with a .csv extension
+    // Store all internal output relations to the output dir with a .csv extension
     const auto& sccOutputRelations = sccGraph->getInternalOutputRelations(scc);
     for (const auto& relation : sccOutputRelations) {
         appendStmt(current, generateStoreRelation(relation));
     }
 
-    // clear expired relations
-    const auto& expiredRelations = relationSchedule->schedule().at(idx).expired();
-    appendStmt(current, generateClearExpiredRelations(expiredRelations));
-
     return mk<ram::Sequence>(std::move(current));
 }
 
@@ -749,9 +745,16 @@ Own<ram::Sequence> AstToRamTranslator::translateProgram(const ast::TranslationUn
 
     // Create subroutines for each SCC according to topological order
     for (size_t i = 0; i < sccOrdering.size(); i++) {
-        auto sccCode = generateStratum(sccOrdering.at(i), i);
+        // Generate the main stratum code
+        auto stratum = generateStratum(sccOrdering.at(i));
+
+        // Clear expired relations
+        const auto& expiredRelations = relationSchedule->schedule().at(i).expired();
+        stratum = mk<ram::Sequence>(std::move(stratum), generateClearExpiredRelations(expiredRelations));
+
+        // Add the subroutine
         std::string stratumID = "stratum_" + toString(i);
-        addRamSubroutine(stratumID, std::move(sccCode));
+        addRamSubroutine(stratumID, std::move(stratum));
     }
 
     // Invoke all strata
diff --git a/src/ast2ram/AstToRamTranslator.h b/src/ast2ram/AstToRamTranslator.h
index d324d4cffa2..66edcb12bdf 100644
--- a/src/ast2ram/AstToRamTranslator.h
+++ b/src/ast2ram/AstToRamTranslator.h
@@ -115,7 +115,6 @@ class AstToRamTranslator {
     void addRamRelation(std::string relationName, Own<ram::Relation> ramRelation);
 
     // clean up
-    Own<ram::Statement> generateStratum(size_t scc, size_t idx) const;
     virtual Own<ast::Clause> createDeltaClause(const ast::Clause* original, size_t recursiveAtomIdx) const;
     RamDomain getConstantRamRepresentation(const ast::Constant& constant) const;
     Own<ram::Statement> translateRecursiveClauses(
@@ -132,6 +131,7 @@ class AstToRamTranslator {
     Own<ram::Statement> generateLoadRelation(const ast::Relation* relation) const;
 
     /** Low-level stratum translation */
+    Own<ram::Statement> generateStratum(size_t scc) const;
     Own<ram::Statement> generateStratumPreamble(const std::set<const ast::Relation*>& scc) const;
     Own<ram::Statement> generateStratumPostamble(const std::set<const ast::Relation*>& scc) const;
     Own<ram::Statement> generateStratumLoopBody(const std::set<const ast::Relation*>& scc) const;