diff --git a/lib/codegen/selection/generator.cc b/lib/codegen/selection/generator.cc
index 7e580251c..6bd62ba81 100644
--- a/lib/codegen/selection/generator.cc
+++ b/lib/codegen/selection/generator.cc
@@ -711,11 +711,35 @@ void generator::visit_atomic_add_inst(ir::atomic_add_inst* add) {
     distributed_tile* vals = (distributed_tile*)tmap_.at(val);
     distributed_tile* msks = (distributed_tile*)tmap_.at(msk);
     
-    for_each(ptr, [&](indices_t idx){
+    // vector size
+    int vector_size = 1;
+    int ld = ptrs->get_order()[0];
+    unsigned alignment = alignment_->get(ptr, ld);
+    vector_size = gcd(ptrs->axis(ld).contiguous, alignment);
+    vector_size = std::min(vector_size, val->get_type()->get_tile_element_ty()->is_half_ty() ? 2 : 1);
+    vector_size = 1;
+
+    std::map<unsigned, Value*> packets;
+    for_each(val, [&](indices_t idx){
+      unsigned linear = vals->get_linear_index(idx);
+      unsigned id = linear / vector_size;
+      Value *in_value = vals->get_value(idx);
+      if(linear % vector_size == 0)
+        packets[id] = UndefValue::get(VectorType::get(in_value->getType(), vector_size));
+      packets[id] = builder_->CreateInsertElement(packets.at(id), in_value, linear % vector_size);
+    });
+
+    for_each(val, [&](indices_t idx){
       Value *rmw_ptr = ptrs->get_value(idx);
-      Value *rmw_val = vals->get_value(idx);
       Value *rmw_msk = msks->get_value(idx);
+      unsigned linear = vals->get_linear_index(idx);
+      unsigned id = linear / vector_size;
+      if(linear % vector_size != 0)
+        return;
       // num bytes
+      Value *rmw_val = packets[id];
+      if(vector_size == 1)
+        rmw_val = builder_->CreateExtractElement(rmw_val, builder_->getInt32(0));
       Type* ty = rmw_val->getType();
       size_t nbits = ty->getScalarSizeInBits();
       // extract pointer offset
@@ -732,9 +756,10 @@ void generator::visit_atomic_add_inst(ir::atomic_add_inst* add) {
       // asm function type
       FunctionType *fn_ty = FunctionType::get(ty, arg_ty, false);
       // asm string
+      std::string suffix = vector_size == 2 ? "x2" : ""; 
       std::string mod = nbits == 32 ? "" : ".noftz";
-      std::string asm_str = "@$0 atom.global.sys.add" + mod + ".f" + std::to_string(nbits) + " $1, [$2" + offset + "], $3;";
-      std::string ty_id = nbits == 32 ? "f" : "h";
+      std::string asm_str = "@$0 atom.global.gpu.add" + mod + ".f" + std::to_string(nbits) + suffix + " $1, [$2" + offset + "], $3;";
+      std::string ty_id = nbits == 32 ? "f" : (vector_size == 1 ? "h" : "r");
       std::string constraint = "b,=" + ty_id + ",l," + ty_id;
       // create inline asm
       InlineAsm *iasm = InlineAsm::get(fn_ty, asm_str, constraint, true);