diff --git a/include/triton/lang/ast.h b/include/triton/lang/ast.h
index 8bf96a96b..43cfc485f 100644
--- a/include/triton/lang/ast.h
+++ b/include/triton/lang/ast.h
@@ -418,22 +418,25 @@ class UnaryOp : public Expr {
   friend class LValAssigner;
 
 public:
-  static UnaryOp* New(int op, Expr* operand, QualType type=nullptr);
+  static UnaryOp* New(int op, Expr* operand, QualType type=nullptr, int info=0);
   virtual ~UnaryOp() {}
   virtual void Accept(Visitor* v);
   virtual bool IsLVal();
   ::Type *Convert();
+  static int encodeRed(int ax, int tag);
+  static void decodeRed(int info, int& ax, int& tag);
   void TypeChecking();
   void IncDecOpTypeChecking();
   void AddrOpTypeChecking();
   void DerefOpTypeChecking();
+  void ReduceOpTypeChecking();
   void TransOpTypeChecking();
   void UnaryArithmOpTypeChecking();
   void CastOpTypeChecking();
 
 protected:
-  UnaryOp(int op, Expr* operand, QualType type=nullptr)
-    : Expr(operand->Tok(), type), op_(op) {
+  UnaryOp(int op, Expr* operand, QualType type=nullptr, int info=0)
+    : Expr(operand->Tok(), type), op_(op), info_(info) {
       operand_ = operand;
       if (op_ != Token::CAST && op_ != Token::ADDR) {
         operand_ = MayCast(operand);
@@ -441,6 +444,7 @@ protected:
     }
 
   int op_;
+  int info_;
   Expr* operand_;
 };
 
diff --git a/include/triton/lang/token.h b/include/triton/lang/token.h
index 5724c50e3..602113f93 100644
--- a/include/triton/lang/token.h
+++ b/include/triton/lang/token.h
@@ -180,9 +180,7 @@ public:
     PLUS,
     MINUS,
     CAST,
-    REDUCE_ADD,
-    REDUCE_MAX,
-    REDUCE_MIN,
+    REDUCE,
 
     // For preprocessor
     PP_IF,
diff --git a/lib/codegen/selection.cc b/lib/codegen/selection.cc
index ff246f4f5..02611444f 100644
--- a/lib/codegen/selection.cc
+++ b/lib/codegen/selection.cc
@@ -962,7 +962,9 @@ void selection::lower_reduce(ir::reduce_inst *x, LLVMContext &ctx, Function *fn,
     tgt_->add_barrier(module, builder);
     builder.CreateStore(result, write_ptr);
     // build result
-    unsigned depth = params_->get_param(op, "wpt.d" + std::to_string(axis))->get_value();
+    unsigned shape_ax = op->get_type()->get_tile_shapes()[axis];
+    unsigned per_thread = op_tile->axis(axis).values.size();
+    unsigned depth = shape_ax / per_thread;
     for(unsigned i = depth/2; i > 0; i >>= 1){
       // current indices
       indices_t current(write_idx.size(), builder.getInt32(0));
diff --git a/lib/lang/ast.cc b/lib/lang/ast.cc
index e1f008c36..b0a50adc3 100644
--- a/lib/lang/ast.cc
+++ b/lib/lang/ast.cc
@@ -448,6 +448,8 @@ void BinaryOp::RangeOpTypeChecking() {
 }
 
 void BinaryOp::MaskedDerefOpTypeChecking() {
+//  auto lhsTileType = lhs_->Type()->ToTile();
+//  auto rhsTileType = rhs_->Type()->ToTile();
   ::Type* lhsScalType = TryExtractScalarType(this, lhs_);
   ::Type* rhsScalType = TryExtractScalarType(this, rhs_);
   auto lhsType = lhsScalType->ToArithm();
@@ -572,8 +574,8 @@ void BinaryOp::AssignOpTypeChecking() {
  * Unary Operators
  */
 
-UnaryOp* UnaryOp::New(int op, Expr* operand, QualType type) {
-  auto ret = new (unaryOpPool.Alloc()) UnaryOp(op, operand, type);
+UnaryOp* UnaryOp::New(int op, Expr* operand, QualType type, int info) {
+  auto ret = new (unaryOpPool.Alloc()) UnaryOp(op, operand, type, info);
   ret->pool_ = &unaryOpPool;
 
   ret->TypeChecking();
@@ -581,6 +583,18 @@ UnaryOp* UnaryOp::New(int op, Expr* operand, QualType type) {
 }
 
 
+int UnaryOp::encodeRed(int ax, int tag) {
+  int result = 0;
+  result |= ax;
+  result |= tag << 16;
+  return result;
+}
+
+void UnaryOp::decodeRed(int info, int& ax, int& tag) {
+  ax = info & 0x0000FFFF;
+  tag = (info & 0xFFFF0000) >> 16;
+}
+
 bool UnaryOp::IsLVal() {
   // Only deref('*') could be lvalue;
   return op_ == Token::DEREF;
@@ -626,6 +640,9 @@ void UnaryOp::TypeChecking() {
   case '^':
     return TransOpTypeChecking();
 
+  case Token::REDUCE:
+    return ReduceOpTypeChecking();
+
   default:
     assert(false);
   }
@@ -663,6 +680,16 @@ void UnaryOp::DerefOpTypeChecking() {
   type_ = ScalarOrLikeTile(operand_, pointerType->Derived().GetPtr());
 }
 
+void UnaryOp::ReduceOpTypeChecking() {
+  int ax, tag;
+  decodeRed(info_, ax, tag);
+  auto tileType = operand_->Type()->ToTile();
+  if(!tileType)
+    Error(this, "array expected for reduction operation");
+  auto shape = tileType->Shape();
+  shape.erase(shape.begin() + ax);
+  type_ = TileType::New(shape, tileType->Derived());
+}
 
 void UnaryOp::TransOpTypeChecking() {
   auto tileType = operand_->Type()->ToTile();
diff --git a/lib/lang/code_gen.cc b/lib/lang/code_gen.cc
index 228bd69dd..56acb1c03 100644
--- a/lib/lang/code_gen.cc
+++ b/lib/lang/code_gen.cc
@@ -174,6 +174,11 @@ void Generator::VisitUnaryOp(UnaryOp* unary) {
     case '!': return set_ret(bld_->create_not(op));
     case Token::CAST: return set_ret(GenCastOp(op, GenIRType(unary->Type(), *ctx_)));
     case '^': return set_ret(bld_->create_trans(op));
+    case Token::REDUCE: {
+      int ax, tag;
+      UnaryOp::decodeRed(unary->info_, ax, tag);
+      return set_ret(bld_->create_reduce(op, ax));
+    }
     default: error_not_implemented();
   }
   return error_not_implemented();
@@ -412,16 +417,41 @@ void Generator::Gen(ir::module *mod) {
 
 
 ir::value* Generator::GenBroadcastOp(ir::value* src, ir::type* dst_ty) {
+  if(src->get_type() == dst_ty)
+    return src;
   if(dst_ty->is_tile_ty()) {
     ir::type *src_ty = src->get_type();
     auto dst_shapes = dst_ty->get_tile_shapes();
     if(!src_ty->is_tile_ty())
       return bld_->create_splat(src, dst_shapes);
     auto src_shapes = src_ty->get_tile_shapes();
-    if(src_shapes.size() != dst_shapes.size())
-      return bld_->create_reshape(src, dst_shapes);
-    else
+    if(src_shapes.size() != dst_shapes.size()){
+      unsigned src_numel = 1;
+      for(unsigned s: src_shapes)
+        src_numel *= s;
+      unsigned dst_numel = 1;
+      for(unsigned s: dst_shapes)
+        dst_numel *= s;
+      if(src_numel == dst_numel)
+        return bld_->create_reshape(src, dst_shapes);
+      else {
+        auto padded_shapes = src_shapes;
+        while(padded_shapes.size() != dst_shapes.size())
+          padded_shapes.insert(padded_shapes.begin(), 1);
+        // check that broadcast is legal
+        for(size_t d = 0; d < padded_shapes.size(); d++){
+          if(dst_shapes[d] != padded_shapes[d] &&
+             padded_shapes[d] != 1)
+            should_not_happen();
+        }
+        // pad and broadcast
+        ir::value *padded = bld_->create_reshape(src, padded_shapes);
+        return bld_->create_broadcast(padded, dst_shapes);
+      }
+    }
+    else{
       return bld_->create_broadcast(src, dst_shapes);
+    }
   }
   return src;
 }
diff --git a/lib/lang/parser.cc b/lib/lang/parser.cc
index 6c669208f..f69337ced 100644
--- a/lib/lang/parser.cc
+++ b/lib/lang/parser.cc
@@ -453,7 +453,7 @@ Expr* Parser::ParseSubScripting(Expr* lhs) {
   TileType::ShapeInt shape;
   size_t i = 0;
   const Token* tok;
-  std::vector<std::pair<int, int>> redList;
+  std::vector<std::pair<int, int>> redInfo;
   do {
     tok = ts_.Next();
     switch(tok->tag_) {
@@ -465,10 +465,13 @@ Expr* Parser::ParseSubScripting(Expr* lhs) {
         shape.push_back(1);
         break;
 
-//      case Token::ADD:
-//      case Token::SUB:
-//        redList.push_back({i, tok->tag_});
-//        break;
+      case Token::ADD:
+      case Token::SUB:{
+          int info = UnaryOp::encodeRed(i, tok->tag_);
+          redInfo.push_back({i, info});
+          shape.push_back(lhsShape[i++]);
+          break;
+      }
 
       default:
         Error(tok, "Unexpected subscript symbol encountered at dimension %d", i);
@@ -479,8 +482,21 @@ Expr* Parser::ParseSubScripting(Expr* lhs) {
   if(lhsShape.size() > i)
     Error(tok, "broadcasting not using all operand axes");
   // create ret tile
-  TileType *retType = TileType::New(shape, lhsQual);
-  return UnaryOp::New(Token::CAST, lhs, retType);
+  Expr* res = lhs;
+  for(auto r: redInfo){
+    shape.erase(shape.begin() + r.first);
+    Type *retType;
+    if(shape.empty())
+      retType = lhsQual.GetPtr();
+    else
+      retType = TileType::New(shape, lhsQual);
+    res = UnaryOp::New(Token::REDUCE, res, retType, r.second);
+  }
+  if(!shape.empty()){
+    TileType *retType = TileType::New(shape, lhsQual);
+    res = UnaryOp::New(Token::CAST, res, retType);
+  }
+  return res;
 }
 
 
diff --git a/lib/runtime/function.cc b/lib/runtime/function.cc
index 114626dce..ae21128f6 100644
--- a/lib/runtime/function.cc
+++ b/lib/runtime/function.cc
@@ -204,6 +204,7 @@ std::unique_ptr<driver::module> function::make_bin(ir::module &module, driver::c
   codegen::transform::peephole peephole;
   codegen::transform::reassociate reassociate(&alignment_info, &grids);
   codegen::selection selection(&shmem_allocation, &grids, &shmem_info, &alignment_info, target.get());
+//  ir::print(module, std::cout);
   // run passes
   peephole.run(module);
   dce.run(module);
diff --git a/tests/common/src/reduce.h b/tests/common/src/reduce.h
index a9788f340..1f2be7461 100644
--- a/tests/common/src/reduce.h
+++ b/tests/common/src/reduce.h
@@ -19,7 +19,7 @@ void reduce2d(TYPE * X __noalias __readonly __aligned(16),
   int rm[TM] = ridm * TM + 0 ... TM;
   int rn[TN] = ridn * TN + 0 ... TN;
   TYPE* px[TM, TN] = X + rm[:, newaxis] + rn[newaxis, :] * ldx;
-  TYPE* py[TM, TN] = Y + rm[:, newaxis];
+  TYPE* py[TM] = Y + rm;
   *py = (*px)[:, +];
 }
 )";
diff --git a/tests/common/util.h b/tests/common/util.h
index e5cfef7b8..874b33e84 100644
--- a/tests/common/util.h
+++ b/tests/common/util.h
@@ -37,6 +37,12 @@ void init_rand(std::vector<T>& x) {
     x[i] = static_cast<T>((double)rand()/RAND_MAX);
 }
 
+template<class T>
+void init_zeros(std::vector<T>& x) {
+  for(size_t i = 0; i < x.size(); i++)
+    x[i] = 0;
+}
+
 
 
 namespace aux{
diff --git a/tests/unit/reduce.cc b/tests/unit/reduce.cc
index 59b574c4d..c513d9cb5 100644
--- a/tests/unit/reduce.cc
+++ b/tests/unit/reduce.cc
@@ -15,15 +15,26 @@ namespace drv = triton::driver;
 namespace rt = triton::runtime;
 
 
+template<class T>
+void cpu_ref(std::vector<T> &y, const std::vector<T> &x, int M, int N) {
+  for(int m = 0; m < M; m++){
+    T acc = 0;
+    for(int n = 0; n < N; n++)
+      acc = acc + x[m + n*M];
+    y[m] = acc;
+  }
+}
+
 bool do_test(drv::stream* stream, int M, int N, std::string op, int nwarp){
   typedef float NumericT;
   std::string ty = "float";
   size_t dt_nbytes = sizeof(NumericT);
   drv::context* context = stream->context();
   std::vector<NumericT> hy(M);
+  std::vector<NumericT> ry(M);
   std::vector<NumericT> hx(M*N);
   srand(0);
-  init_rand(hy);
+  init_zeros(hy);
   init_rand(hx);
   auto dy = std::shared_ptr<drv::buffer>(drv::buffer::create(context, hy.size()*dt_nbytes));
   auto dx = std::shared_ptr<drv::buffer>(drv::buffer::create(context, hx.size()*dt_nbytes));
@@ -35,8 +46,11 @@ bool do_test(drv::stream* stream, int M, int N, std::string op, int nwarp){
   opt.defines.push_back({"TN", {std::to_string(N)}});
   opt.num_warps = {nwarp};
   rt::function function(src::reduce2d, opt);
-  function({&*dy, &*dx, M, N, M}, grid2d(M, N), stream);
+  function({&*dx, &*dy, M, N, M}, grid2d(M, N), stream);
   stream->synchronize();
+  stream->read(&*dy, true, 0, hy);
+  cpu_ref(ry, hx, M, N);
+  return testing::diff(hy, ry);
 }
 
 int main() {