diff options
| -rw-r--r-- | src/passes/RemoveUnusedBrs.cpp | 16 | ||||
| -rw-r--r-- | test/emcc_hello_world.fromasm | 1 | ||||
| -rw-r--r-- | test/emcc_hello_world.fromasm.imprecise | 1 | ||||
| -rw-r--r-- | test/passes/remove-unused-brs.txt | 8 |
4 files changed, 19 insertions, 7 deletions
diff --git a/src/passes/RemoveUnusedBrs.cpp b/src/passes/RemoveUnusedBrs.cpp index 255d86b9c..3d6d6973f 100644 --- a/src/passes/RemoveUnusedBrs.cpp +++ b/src/passes/RemoveUnusedBrs.cpp @@ -27,6 +27,8 @@ namespace wasm { struct RemoveUnusedBrs : public WalkerPass<PostWalker<RemoveUnusedBrs, Visitor<RemoveUnusedBrs>>> { bool isFunctionParallel() { return true; } + bool anotherCycle; + typedef std::vector<Break*> Flows; // list of breaks that are currently flowing. if they reach their target without @@ -68,6 +70,7 @@ struct RemoveUnusedBrs : public WalkerPass<PostWalker<RemoveUnusedBrs, Visitor<R if (flows[i]->name == name) { ExpressionManipulator::nop(flows[i]); skip++; + self->anotherCycle = true; } else if (skip > 0) { flows[i - skip] = flows[i]; } @@ -79,6 +82,8 @@ struct RemoveUnusedBrs : public WalkerPass<PostWalker<RemoveUnusedBrs, Visitor<R } else if (curr->is<Loop>()) { // TODO we might optimize branches out of here flows.clear(); + } else if (curr->is<Nop>()) { + // ignore (could be result of a previous cycle) } else { // anything else stops the flow flows.clear(); @@ -100,6 +105,7 @@ struct RemoveUnusedBrs : public WalkerPass<PostWalker<RemoveUnusedBrs, Visitor<R if (br && !br->condition) { // TODO: if there is a condition, join them br->condition = curr->condition; replaceCurrent(br); + anotherCycle = true; } } } @@ -125,7 +131,15 @@ struct RemoveUnusedBrs : public WalkerPass<PostWalker<RemoveUnusedBrs, Visitor<R } } - // TODO: multiple rounds? + void walk(Expression*& root) { + // multiple cycles may be needed + do { + anotherCycle = false; + WalkerPass<PostWalker<RemoveUnusedBrs, Visitor<RemoveUnusedBrs>>>::walk(root); + assert(ifStack.empty()); + assert(flows.empty()); + } while (anotherCycle); + } }; static RegisterPass<RemoveUnusedBrs> registerPass("remove-unused-brs", "removes breaks from locations that are not needed"); diff --git a/test/emcc_hello_world.fromasm b/test/emcc_hello_world.fromasm index 9d50d32b2..75e2bf024 100644 --- a/test/emcc_hello_world.fromasm +++ b/test/emcc_hello_world.fromasm @@ -10864,7 +10864,6 @@ (get_local $$arg) (get_local $$110) ) - (br $label$break$L1) ) ) ) diff --git a/test/emcc_hello_world.fromasm.imprecise b/test/emcc_hello_world.fromasm.imprecise index b303c5cac..4ada9b367 100644 --- a/test/emcc_hello_world.fromasm.imprecise +++ b/test/emcc_hello_world.fromasm.imprecise @@ -10862,7 +10862,6 @@ (get_local $$arg) (get_local $$110) ) - (br $label$break$L1) ) ) ) diff --git a/test/passes/remove-unused-brs.txt b/test/passes/remove-unused-brs.txt index 2404e7b39..226065f3f 100644 --- a/test/passes/remove-unused-brs.txt +++ b/test/passes/remove-unused-brs.txt @@ -169,9 +169,9 @@ (block $a (block $b (block $c - (br $a) + (nop) ) - (br $a) + (nop) ) (nop) ) @@ -187,9 +187,9 @@ (block $a (block $b (block $c - (br $b) + (nop) ) - (br $a) + (nop) ) (nop) ) |