Use unordered maps of Name where possible (#3546)

Unordered maps will hash the pointer, while ordered ones will compare the
strings to find where to insert in the tree. I cannot confirm a speedup in time
from this, though others can, but I do see a consistent improvement of a
few % in perf stat results like number of instructions and cycles (and those
results have little noise). And it seems logical that this could be faster.

3 files changed, 11 insertions, 11 deletions

diff --git a/src/wasm.h b/src/wasm.h
index 0050fcc28..5e4c4668b 100644
--- a/src/wasm.h
+++ b/src/wasm.h
@@ -1643,8 +1643,8 @@ public:
   std::unique_ptr<StackIR> stackIR;
 
   // local names. these are optional.
-  std::map<Index, Name> localNames;
-  std::map<Name, Index> localIndices;
+  std::unordered_map<Index, Name> localNames;
+  std::unordered_map<Name, Index> localIndices;
 
   // Source maps debugging info: map expression nodes to their file, line, col.
   struct DebugLocation {
@@ -1878,10 +1878,10 @@ private:
   // TODO: add a build option where Names are just indices, and then these
   // methods are not needed
   // exports map is by the *exported* name, which is unique
-  std::map<Name, Export*> exportsMap;
-  std::map<Name, Function*> functionsMap;
-  std::map<Name, Global*> globalsMap;
-  std::map<Name, Event*> eventsMap;
+  std::unordered_map<Name, Export*> exportsMap;
+  std::unordered_map<Name, Function*> functionsMap;
+  std::unordered_map<Name, Global*> globalsMap;
+  std::unordered_map<Name, Event*> eventsMap;
 
 public:
   Module() = default;
diff --git a/src/wasm/wasm-binary.cpp b/src/wasm/wasm-binary.cpp
index 2c473a254..75ca5a2b1 100644
--- a/src/wasm/wasm-binary.cpp
+++ b/src/wasm/wasm-binary.cpp
@@ -1894,7 +1894,7 @@ void WasmBinaryBuilder::readExports() {
   BYN_TRACE("== readExports\n");
   size_t num = getU32LEB();
   BYN_TRACE("num: " << num << std::endl);
-  std::set<Name> names;
+  std::unordered_set<Name> names;
   for (size_t i = 0; i < num; i++) {
     BYN_TRACE("read one\n");
     auto curr = new Export;
@@ -2524,7 +2524,7 @@ void WasmBinaryBuilder::readNames(size_t payloadLen) {
     } else if (nameType ==
                BinaryConsts::UserSections::Subsection::NameFunction) {
       auto num = getU32LEB();
-      std::set<Name> usedNames;
+      std::unordered_set<Name> usedNames;
       for (size_t i = 0; i < num; i++) {
         auto index = getU32LEB();
         auto rawName = getInlineString();
@@ -2563,7 +2563,7 @@ void WasmBinaryBuilder::readNames(size_t payloadLen) {
             << std::to_string(funcIndex) << std::endl;
         }
         auto numLocals = getU32LEB();
-        std::set<Name> usedNames;
+        std::unordered_set<Name> usedNames;
         for (size_t j = 0; j < numLocals; j++) {
           auto localIndex = getU32LEB();
           auto rawLocalName = getInlineString();
@@ -2631,7 +2631,7 @@ void WasmBinaryBuilder::readNames(size_t payloadLen) {
       }
     } else if (nameType == BinaryConsts::UserSections::Subsection::NameGlobal) {
       auto num = getU32LEB();
-      std::set<Name> usedNames;
+      std::unordered_set<Name> usedNames;
       for (size_t i = 0; i < num; i++) {
         auto index = getU32LEB();
         auto rawName = getInlineString();
diff --git a/src/wasm/wasm-validator.cpp b/src/wasm/wasm-validator.cpp
index a9a69b244..fad78cefd 100644
--- a/src/wasm/wasm-validator.cpp
+++ b/src/wasm/wasm-validator.cpp
@@ -2465,7 +2465,7 @@ void FunctionValidator::visitFunction(Function* curr) {
   returnTypes.clear();
   labelNames.clear();
   // validate optional local names
-  std::set<Name> seen;
+  std::unordered_set<Name> seen;
   for (auto& pair : curr->localNames) {
     Name name = pair.second;
     shouldBeTrue(seen.insert(name).second, name, "local names must be unique");