diff options
| -rw-r--r-- | src/passes/CoalesceLocals.cpp | 22 |
1 files changed, 17 insertions, 5 deletions
diff --git a/src/passes/CoalesceLocals.cpp b/src/passes/CoalesceLocals.cpp index 05756556b..311280792 100644 --- a/src/passes/CoalesceLocals.cpp +++ b/src/passes/CoalesceLocals.cpp @@ -185,7 +185,9 @@ struct CoalesceLocals : public WalkerPass<CFGWalker<CoalesceLocals, Visitor<Coal void scanLivenessThroughActions(std::vector<Action>& actions, LocalSet& live); - std::vector<Index> pickIndices(); // returns a vector of oldIndex => newIndex + void pickIndicesFromOrder(std::vector<Index>& order, std::vector<Index>& indices); + + virtual void pickIndices(std::vector<Index>& indices); // returns a vector of oldIndex => newIndex void applyIndices(std::vector<Index>& indices, Expression* root); @@ -230,7 +232,8 @@ void CoalesceLocals::walk(Expression*& root) { timer.dump(); #endif // pick new indices - auto indices = pickIndices(); + std::vector<Index> indices; + pickIndices(indices); // apply indices applyIndices(indices, root); } @@ -346,12 +349,11 @@ void CoalesceLocals::scanLivenessThroughActions(std::vector<Action>& actions, Lo // Indices decision making -std::vector<Index> CoalesceLocals::pickIndices() { // returns a vector of oldIndex => newIndex +void CoalesceLocals::pickIndicesFromOrder(std::vector<Index>& order, std::vector<Index>& indices) { // simple greedy coloring // TODO: multiple orderings // TODO: take into account eliminated copies // TODO: take into account distribution (99-1 is better than 50-50 with two registers, for gzip) - std::vector<Index> indices; // old => new std::vector<WasmType> types; std::vector<bool> newInterferences; // new index * numLocals => list of all interferences of locals merged to it indices.resize(numLocals); @@ -388,7 +390,17 @@ std::vector<Index> CoalesceLocals::pickIndices() { // returns a vector of oldInd newInterferences[found * numLocals + j] = newInterferences[found * numLocals + j] | interferes(i, j); } } - return indices; +} + +void CoalesceLocals::pickIndices(std::vector<Index>& indices) { + // use the natural order. this is less arbitrary than it seems, as the program + // may have a natural order of locals inherent in it. + std::vector<Index> order; + order.resize(numLocals); + for (size_t i = 0; i < numLocals; i++) { + order[i] = i; + } + pickIndicesFromOrder(order, indices); } void CoalesceLocals::applyIndices(std::vector<Index>& indices, Expression* root) { |