1 files changed, 15 insertions, 12 deletions

diff --git a/src/passes/MemoryPacking.cpp b/src/passes/MemoryPacking.cpp
index 5f72a916d..e0ce6294b 100644
--- a/src/passes/MemoryPacking.cpp
+++ b/src/passes/MemoryPacking.cpp
@@ -710,6 +710,7 @@ void MemoryPacking::createReplacements(Module* module,
 
     size_t bytesWritten = 0;
 
+    auto is64 = module->getMemory(init->memory)->is64();
     for (size_t i = firstRangeIdx; i < ranges.size() && ranges[i].start < end;
          ++i) {
       auto& range = ranges[i];
@@ -721,12 +722,12 @@ void MemoryPacking::createReplacements(Module* module,
         dest =
           builder.makeConstPtr(c->value.getInteger() + bytesWritten, ptrType);
       } else {
-        auto* get = builder.makeLocalGet(-1, Type::i32);
+        auto* get = builder.makeLocalGet(-1, ptrType);
         getVars.push_back(&get->index);
         dest = get;
         if (bytesWritten > 0) {
-          Const* addend = builder.makeConst(int32_t(bytesWritten));
-          dest = builder.makeBinary(AddInt32, dest, addend);
+          Const* addend = builder.makeConstPtr(bytesWritten, ptrType);
+          dest = builder.makeBinary(is64 ? AddInt64 : AddInt32, dest, addend);
         }
       }
 
@@ -751,16 +752,18 @@ void MemoryPacking::createReplacements(Module* module,
 
     // Non-zero length memory.inits must have intersected some range
     assert(result);
-    replacements[init] = [module, setVar, getVars, result](Function* function) {
-      if (setVar != nullptr) {
-        Index destVar = Builder(*module).addVar(function, Type::i32);
-        *setVar = destVar;
-        for (auto* getVar : getVars) {
-          *getVar = destVar;
+    replacements[init] =
+      [module, init, setVar, getVars, result](Function* function) {
+        if (setVar != nullptr) {
+          auto indexType = module->getMemory(init->memory)->indexType;
+          Index destVar = Builder(*module).addVar(function, indexType);
+          *setVar = destVar;
+          for (auto* getVar : getVars) {
+            *getVar = destVar;
+          }
         }
-      }
-      return result;
-    };
+        return result;
+      };
   }
 
   // Create replacements for data.drop instructions now that we know whether we