diff --git a/examples/python/tensorflow/blocksparse.cpp b/examples/python/tensorflow/blocksparse.cpp
index b86c6bcab..d6b305fcf 100644
--- a/examples/python/tensorflow/blocksparse.cpp
+++ b/examples/python/tensorflow/blocksparse.cpp
@@ -101,6 +101,7 @@ typedef struct bsmm_params
   CUstream stream;
 } bsmm_params;
 
+template<typename T>
 class BlocksparseMatmulOp : public OpKernel {
 public:
   explicit BlocksparseMatmulOp(OpKernelConstruction* ctx) : OpKernel(ctx) {
@@ -152,29 +153,23 @@ public:
         shape_c.AddDim(params_.K);
     Tensor* c = nullptr;
     OP_REQUIRES_OK(context, context->allocate_output(0, shape_c, &c));
-    // grid and block
-    int blkN = 128, gridN = (N + 127)/128, modN128 = N & 127;
-    if (axis_ == 1 || (modN128 > 0 && modN128 <= 64) || gridN * params_.segments < SMs_*4){
-      blkN  = 64;
-      gridN = (N + 63)/64;
-    }
     // allocate locks
+    int gridN = (N + 63)/64;
     Tensor* locks;
     TensorShape shape_l;
     if (params_.locks > 0)
       shape_l.AddDim(gridN * params_.locks * 2);
     OP_REQUIRES_OK(context, context->allocate_output(1, shape_l, &locks));
-    // initialize default compute device
-    triton::runtime::jit jit(ctx);
-    // matrix multiplication parameters
-    triton::driver::cu_buffer da(ctx, (CUdeviceptr)a.flat<float>().data(), false);
-    triton::driver::cu_buffer db(ctx, (CUdeviceptr)b.flat<float>().data(), false);
-    triton::driver::cu_buffer dc(ctx, (CUdeviceptr)c->flat<float>().data(), false);
-//    triton::driver::cu_buffer dlocks(ctx, (CUdeviceptr)locks->flat<int32>().data(), false);
+    // wrap tensorflow handles
+    triton::driver::cu_buffer da(ctx, (CUdeviceptr)a.flat<T>().data(), false);
+    triton::driver::cu_buffer db(ctx, (CUdeviceptr)b.flat<T>().data(), false);
+    triton::driver::cu_buffer dc(ctx, (CUdeviceptr)c->flat<T>().data(), false);
     triton::driver::cu_buffer dlut(ctx, (CUdeviceptr)lut.flat<int64>().data(), false);
+    triton::driver::cu_buffer dlocks(ctx, (CUdeviceptr)locks->flat<int32>().data(), false);
+    // create profile
+    triton::dnn::blocksparse::dot dot(N, params_.K, params_.segments, params_.C, "fp32", params_.bsize, params_.locks);
     // blocksparse matmul
-    triton::dnn::blocksparse::dot dot(N, params_.K, params_.C);
-    dot.enqueue(stream, {&da, &db, &dc, &dlut}, triton::dnn::NO_TUNING);
+    dot.enqueue(stream, {&da, &db, &dc, &dlut, &dlocks}, triton::dnn::NO_TUNING);
   }
 
 private:
@@ -185,4 +180,5 @@ private:
   char bench_string_[256];
 };
 
-REGISTER_KERNEL_BUILDER(Name("TritonBlocksparseMatmul").Device(DEVICE_GPU).TypeConstraint<float>("T"), BlocksparseMatmulOp);
+REGISTER_KERNEL_BUILDER(Name("TritonBlocksparseMatmul").Device(DEVICE_GPU).TypeConstraint<float>("T"), BlocksparseMatmulOp<float>);
+REGISTER_KERNEL_BUILDER(Name("TritonBlocksparseMatmul").Device(DEVICE_GPU).TypeConstraint<Eigen::half>("T"), BlocksparseMatmulOp<Eigen::half>);
diff --git a/include/triton/codegen/target.h b/include/triton/codegen/target.h
index 118ee919f..c080d1c07 100644
--- a/include/triton/codegen/target.h
+++ b/include/triton/codegen/target.h
@@ -23,9 +23,11 @@ public:
   virtual ~target() {}
   virtual void set_kernel(llvm::IRBuilder<>& builder, llvm::LLVMContext &ctx, llvm::Module *module, llvm::Function* fn) = 0;
   virtual llvm::Instruction* add_barrier(llvm::Module *module, llvm::IRBuilder<>& builder) = 0;
+  virtual llvm::Instruction* add_memfence(llvm::Module *module, llvm::IRBuilder<>& builder) = 0;
   virtual llvm::Value* get_global_offset(llvm::Module *module, llvm::IRBuilder<>& builder, unsigned stride, unsigned ax) = 0;
   virtual llvm::Value* get_local_id(llvm::Module *module, llvm::IRBuilder<>& builder, unsigned ax) = 0;
   virtual llvm::Value* get_block_id(llvm::Module *module, llvm::IRBuilder<>& builder, unsigned ax) = 0;
+  virtual llvm::Value* get_num_blocks(llvm::Module *module, llvm::IRBuilder<>& builder, unsigned ax) = 0;
   bool is_gpu() const;
 
 private:
@@ -37,9 +39,11 @@ public:
   amd_cl_target(): target(true){}
   void set_kernel(llvm::IRBuilder<>& builder, llvm::LLVMContext &ctx, llvm::Module *module, llvm::Function* fn);
   llvm::Instruction* add_barrier(llvm::Module *module, llvm::IRBuilder<>& builder);
+  llvm::Instruction* add_memfence(llvm::Module *module, llvm::IRBuilder<>& builder);
   llvm::Value* get_global_offset(llvm::Module *module, llvm::IRBuilder<>& builder, unsigned stride, unsigned ax);
   llvm::Value* get_local_id(llvm::Module *module, llvm::IRBuilder<>& builder, unsigned ax);
   llvm::Value* get_block_id(llvm::Module *module, llvm::IRBuilder<>& builder, unsigned ax);
+  llvm::Value* get_num_blocks(llvm::Module *module, llvm::IRBuilder<>& builder, unsigned ax);
 };
 
 class nvidia_cu_target: public target {
@@ -47,9 +51,11 @@ public:
   nvidia_cu_target(): target(true){}
   void set_kernel(llvm::IRBuilder<>& builder, llvm::LLVMContext &ctx, llvm::Module *module, llvm::Function* fn);
   llvm::Instruction* add_barrier(llvm::Module *module, llvm::IRBuilder<>& builder);
+  llvm::Instruction* add_memfence(llvm::Module *module, llvm::IRBuilder<>& builder);
   llvm::Value* get_global_offset(llvm::Module *module, llvm::IRBuilder<>& builder, unsigned stride, unsigned ax);
   llvm::Value* get_local_id(llvm::Module *module, llvm::IRBuilder<>& builder, unsigned ax);
   llvm::Value* get_block_id(llvm::Module *module, llvm::IRBuilder<>& builder, unsigned ax);
+  llvm::Value* get_num_blocks(llvm::Module *module, llvm::IRBuilder<>& builder, unsigned ax);
 };
 
 class cpu_target: public target {
@@ -57,9 +63,11 @@ public:
   cpu_target(): target(false){}
   void set_kernel(llvm::IRBuilder<>& builder, llvm::LLVMContext &ctx, llvm::Module *module, llvm::Function* fn);
   llvm::Instruction* add_barrier(llvm::Module *module, llvm::IRBuilder<>& builder);
+  llvm::Instruction* add_memfence(llvm::Module *module, llvm::IRBuilder<>& builder);
   llvm::Value* get_global_offset(llvm::Module *module, llvm::IRBuilder<>& builder, unsigned stride, unsigned ax);
   llvm::Value* get_local_id(llvm::Module *module, llvm::IRBuilder<>& builder, unsigned ax);
   llvm::Value* get_block_id(llvm::Module *module, llvm::IRBuilder<>& builder, unsigned ax);
+  llvm::Value* get_num_blocks(llvm::Module *module, llvm::IRBuilder<>& builder, unsigned ax);
 };
 
 }
diff --git a/include/triton/dnn/base.h b/include/triton/dnn/base.h
index 1fbded42c..266f29803 100644
--- a/include/triton/dnn/base.h
+++ b/include/triton/dnn/base.h
@@ -28,6 +28,11 @@
 #include "triton/runtime/launch_info.h"
 
 namespace triton{
+
+namespace runtime{
+  class jit;
+}
+
 namespace dnn{
 
 
@@ -37,6 +42,13 @@ enum autotuning_t{
   NO_TUNING
 };
 
+class base;
+struct launch_context_t{
+  base *op;
+  driver::kernel* kernel;
+  triton::runtime::launch_information info;
+};
+
 typedef std::vector<unsigned> params_t;
 
 class base {
@@ -49,9 +61,9 @@ protected:
 
 private:
   // initialize
-  virtual void init_impl(driver::stream *, driver::cu_module *){ }
+  virtual void init_impl(driver::stream *, driver::cu_module *) = 0;
   // deinitialize
-  virtual void deinit_impl(){ }
+  virtual void deinit_impl() = 0;
   // enqueue
   virtual void enqueue_impl(driver::stream *stream, driver::kernel *kernel,
                     std::vector<driver::buffer*> args,
@@ -63,6 +75,8 @@ private:
   // default parameters
   virtual std::vector<params_t> search_space() const;
   virtual params_t heuristics() const;
+  // obtain execution jit
+  std::pair<base*, triton::runtime::jit*> get_profile_impl(driver::stream *stream, std::vector<driver::buffer *> args, autotuning_t autotune);
 
 public:
   // constructor
@@ -73,6 +87,8 @@ public:
   virtual base* clone() const = 0;
   // enqueue
   void enqueue(driver::stream* stream, std::vector<driver::buffer*> args, autotuning_t autotune = PARTIAL_TUNING);
+  // get profile
+  launch_context_t get_launch_context(driver::stream *stream, std::vector<driver::buffer *> args, autotuning_t autotune = PARTIAL_TUNING);
 
 private:
   std::string name_;
diff --git a/include/triton/dnn/batchnorm.h b/include/triton/dnn/batchnorm.h
index 496e19ae4..8f9053225 100644
--- a/include/triton/dnn/batchnorm.h
+++ b/include/triton/dnn/batchnorm.h
@@ -37,6 +37,10 @@ namespace dnn{
 
 class batchnorm_forward: public base {
 private:
+  // init
+  void init_impl(driver::stream *, driver::cu_module *) { }
+  void deinit_impl() { }
+
   // enqueue
   void enqueue_impl(driver::stream *stream, driver::kernel *kernel,
                             std::vector<driver::buffer*> args,
@@ -69,6 +73,9 @@ private:
 
 class batchnorm_backward: public base{
 private:
+  // init
+  void init_impl(driver::stream *, driver::cu_module *) { }
+  void deinit_impl() { }
   // enqueue
   void enqueue_impl(driver::stream *stream, driver::kernel *kernel,
                             std::vector<driver::buffer*> args,
diff --git a/include/triton/dnn/blocksparse/dot.h b/include/triton/dnn/blocksparse/dot.h
index fbd388937..a1df146fe 100644
--- a/include/triton/dnn/blocksparse/dot.h
+++ b/include/triton/dnn/blocksparse/dot.h
@@ -14,27 +14,34 @@ private:
                     std::vector<driver::buffer*> args,
                     triton::runtime::launch_information info);
   // number of flops
-  virtual size_t num_flops() const;
+  size_t num_flops() const;
   // comparison for maps
-  virtual bool operator<(const base& other) const;
+  bool operator<(const base& other) const;
   // default parameters
-  virtual std::vector<params_t> search_space() const;
-  virtual params_t heuristics() const;
-
+  std::vector<params_t> search_space() const;
+  params_t heuristics() const;
+  // init
+  void init_impl(driver::stream *stream, driver::cu_module *module);
+  // deinit
+  void deinit_impl();
 public:
   // constructor
-  dot(int32_t M, int32_t N, int32_t K);
+  dot(int32_t N, int32_t K, int32_t S, int32_t C, const std::string &ty, int32_t BS, int32_t nlocks);
   // triton-c source
-  virtual void triton_c_src(std::ostream &os) const;
+  void triton_c_src(std::ostream &os) const;
   // clone
-  virtual base* clone() const;
+  base* clone() const;
 
 private:
   std::string ab_ty_;
   std::string c_ty_;
-  int32_t M_;
   int32_t N_;
+  int32_t S_;
+  int32_t C_;
   int32_t K_;
+  int32_t BS_;
+  int32_t nlocks_;
+  driver::buffer *locks_;
 };
 
 }
diff --git a/include/triton/dnn/conv.h b/include/triton/dnn/conv.h
index 1b6f2d778..d81ff872d 100644
--- a/include/triton/dnn/conv.h
+++ b/include/triton/dnn/conv.h
@@ -25,6 +25,7 @@ private:
   void build_a_deltas();
   void build_masks();
   void init_impl(driver::stream *, driver::cu_module *);
+  void deinit_impl() { }
 
   // enqueue
   std::array<size_t, 3> get_grid(size_t TM, size_t TN);
diff --git a/include/triton/dnn/dot.h b/include/triton/dnn/dot.h
index 3df8a13a6..6ba3f0b24 100644
--- a/include/triton/dnn/dot.h
+++ b/include/triton/dnn/dot.h
@@ -10,6 +10,8 @@ class dot: public base {
 private:
   // initialize
   void init_impl(driver::stream *, driver::cu_module *);
+  void deinit_impl() { }
+
   // enqueue
   void enqueue_impl(driver::stream *stream, driver::kernel *kernel,
                     std::vector<driver::buffer*> args,
diff --git a/include/triton/ir/builder.h b/include/triton/ir/builder.h
index 9cee12c68..1921814c9 100644
--- a/include/triton/ir/builder.h
+++ b/include/triton/ir/builder.h
@@ -126,9 +126,10 @@ public:
   value *create_reshape(value *arg, const type::tile_shapes_t &shapes, const std::string &name = "");
   value *create_broadcast(value *arg, const type::tile_shapes_t &shapes, const std::string &name = "");
   // Built-in instruction
-  value *create_get_global_range(unsigned axis, type::tile_shapes_t::value_type size, const std::string &name = "");
   value *create_get_range_id(unsigned axis, const std::string &name = "");
+  value *create_get_num_program(unsigned axis, const std::string &name = "");
   value *create_atomic_cas(value *ptr, value *cmp, value *val, const std::string &name = "");
+  value *create_atomic_exch(value *ptr, value *val, const std::string &name = "");
   value *create_atomic_add(value *ptr, value *val, const std::string &name = "");
   value *create_dot(value *A, value *B, value *C, const std::string &name = "");
   value *create_trans(value *A, const std::string &name = "");
diff --git a/include/triton/ir/instructions.h b/include/triton/ir/instructions.h
index d76ebf719..37692d617 100644
--- a/include/triton/ir/instructions.h
+++ b/include/triton/ir/instructions.h
@@ -514,6 +514,19 @@ private:
   unsigned axis_;
 };
 
+class get_num_program_inst: public builtin_inst {
+private:
+  get_num_program_inst(type *ty, unsigned axis, const std::string &name, instruction *next);
+  std::string repr_impl() const { return "get_num_program(" + std::to_string(axis_) + ")"; }
+
+public:
+  static instruction* create(context &ctx, unsigned axis, const std::string &name = "", instruction *next = nullptr);
+  unsigned get_axis() const { return axis_; }
+
+private:
+  unsigned axis_;
+};
+
 class atomic_cas_inst: public builtin_inst {
 private:
   atomic_cas_inst(value *ptr, value *cmp, value *val, const std::string &name, instruction *next);
@@ -523,6 +536,15 @@ public:
   static instruction* create(value *ptr, value *cmp, value *val, const std::string &name = "", instruction *next = nullptr);
 };
 
+class atomic_exch_inst: public builtin_inst {
+private:
+  atomic_exch_inst(value *ptr, value *val, const std::string &name = "", instruction *next = nullptr);
+  std::string repr_impl() const { return "atomic_exch"; }
+
+public:
+  static instruction* create(value *ptr, value *val, const std::string &name = "", instruction *next = nullptr);
+};
+
 class atomic_add_inst: public builtin_inst {
 private:
   atomic_add_inst(value *ptr, value *val, const std::string &name = "", instruction *next = nullptr);
diff --git a/include/triton/lang/expression.h b/include/triton/lang/expression.h
index 538485366..13894d18a 100644
--- a/include/triton/lang/expression.h
+++ b/include/triton/lang/expression.h
@@ -80,6 +80,15 @@ private:
   const constant* axis_;
 };
 
+class get_num_program_expression: public builtin_expression{
+public:
+  get_num_program_expression(node *axis): axis_((constant*)axis) { }
+  ir::value* codegen(ir::module *mod) const;
+
+private:
+  const constant* axis_;
+};
+
 class atomic_cas_expression: public builtin_expression{
 public:
   atomic_cas_expression(node *ptr, node *cmp, node *val): ptr_(ptr), cmp_(cmp), val_(val) { }
@@ -91,6 +100,17 @@ private:
   const node *val_;
 };
 
+class atomic_exch_expression: public builtin_expression{
+public:
+  atomic_exch_expression(node *ptr, node *val): ptr_(ptr), val_(val) { }
+  ir::value* codegen(ir::module *) const;
+
+private:
+  const node *ptr_;
+  const node *val_;
+};
+
+
 class atomic_add_expression: public builtin_expression{
 public:
   atomic_add_expression(node *ptr, node *val): ptr_(ptr), val_(val) { }
diff --git a/include/triton/lang/parser.y b/include/triton/lang/parser.y
index 645b0b51f..cd2c8941b 100644
--- a/include/triton/lang/parser.y
+++ b/include/triton/lang/parser.y
@@ -55,7 +55,7 @@ STORAGE_SPEC_T get_storage_spec(node *op) { return ((token*)op)->storage_spec;}
 %token VOID UINT1 UINT8 UINT16 UINT32 UINT64 INT1 INT8 INT16 INT32 INT64 FP16 FP32 FP64
 %token IF ELSE FOR CONTINUE WHILE
 %token NEWAXIS ELLIPSIS AT
-%token GET_RANGE_ID DOT SQRT REDUCE_SUM TRANS MAX MIN SELECT ATOMIC_CAS ATOMIC_EXCHG ATOMIC_ADD ALLOC_CONST
+%token GET_NUM_PROGRAM GET_RANGE_ID DOT SQRT REDUCE_SUM TRANS MAX MIN SELECT ATOMIC_CAS ATOMIC_EXCH ATOMIC_ADD ALLOC_CONST
 
 %start translation_unit
 %%
@@ -121,6 +121,7 @@ identifier
 /* Built-in */
 builtin_expression
   : GET_RANGE_ID '(' constant ')'                                { $$ = new get_range_id_expression($3); }
+  | GET_NUM_PROGRAM '(' constant ')'                             { $$ = new get_num_program_expression($3); }
   | DOT '(' expression ',' expression ',' expression ')'         { $$ = new matmul_expression($3, $5, $7); }
   | SQRT '(' expression ')'                                      { $$ = new sqrt_expression($3); }
   | ALLOC_CONST type_specifier '[' constant ']'                  { $$ = new alloc_const_expression(new typed_declaration_specifier(get_type_spec($2)), $4); }
@@ -130,6 +131,7 @@ builtin_expression
   | MIN '(' expression ',' expression ')'                        { $$ = new min_expression($3, $5); }
   | SELECT '(' expression ',' expression ',' expression ')'      { $$ = new select_expression($3, $5, $7); }
   | ATOMIC_CAS '(' expression ',' expression ',' expression ')'  { $$ = new atomic_cas_expression($3, $5, $7); }
+  | ATOMIC_EXCH '(' expression ',' expression ')'                { $$ = new atomic_exch_expression($3, $5); }
   | ATOMIC_ADD '(' expression ',' expression ')'                 { $$ = new atomic_add_expression($3, $5); }
   ;
 
diff --git a/include/triton/lang/scanner.l b/include/triton/lang/scanner.l
index 83d11035d..af691349d 100644
--- a/include/triton/lang/scanner.l
+++ b/include/triton/lang/scanner.l
@@ -45,8 +45,9 @@ using triton::lang::return_void;
 "fp64"                  { return return_impl(FP64, yytext); }
 "..."                   { return return_impl(ELLIPSIS, yytext); }
 "get_range_id"          { return return_impl(GET_RANGE_ID, yytext); }
+"get_num_program"       { return return_impl(GET_NUM_PROGRAM, yytext); }
 "__atomic_cas"          { return return_impl(ATOMIC_CAS, yytext); }
-"__atomic_exchg"        { return return_impl(ATOMIC_EXCHG, yytext); }
+"__atomic_exch"         { return return_impl(ATOMIC_EXCH, yytext); }
 "__atomic_add"          { return return_impl(ATOMIC_ADD, yytext); }
 "__sum"                 { return return_impl(REDUCE_SUM, yytext); }
 "sqrt"                  { return return_impl(SQRT, yytext); }
diff --git a/lib/codegen/optimize_dce.cpp b/lib/codegen/optimize_dce.cpp
index d30bf4c1d..9508cfa2e 100644
--- a/lib/codegen/optimize_dce.cpp
+++ b/lib/codegen/optimize_dce.cpp
@@ -19,7 +19,8 @@ void optimize_dce::run(ir::module &mod) {
     for(ir::basic_block *block: rpo)
     for(ir::instruction *i: block->get_inst_list()){
       if(dynamic_cast<ir::io_inst*>(i) || dynamic_cast<ir::copy_to_shared_inst*>(i) || dynamic_cast<ir::return_inst*>(i)
-         || dynamic_cast<ir::branch_inst*>(i) || dynamic_cast<ir::cond_branch_inst*>(i)){
+         || dynamic_cast<ir::branch_inst*>(i) || dynamic_cast<ir::cond_branch_inst*>(i)
+         || dynamic_cast<ir::atomic_cas_inst*>(i) || dynamic_cast<ir::atomic_exch_inst*>(i) || dynamic_cast<ir::atomic_add_inst*>(i) ){
         work_list.push_back(i);
         marked.insert(i);
       }
diff --git a/lib/codegen/selection.cpp b/lib/codegen/selection.cpp
index 5ab9c55f8..ad7e395b1 100644
--- a/lib/codegen/selection.cpp
+++ b/lib/codegen/selection.cpp
@@ -319,8 +319,12 @@ Instruction *selection::llvm_inst(ir::instruction *inst, std::function<Value*(ir
     return builder.Insert(SelectInst::Create(pred, if_value, else_value));
   }
   if(ir::get_range_id_inst* ii = dynamic_cast<ir::get_range_id_inst*>(inst)){
-    Value *offset = tgt_->get_block_id(builder.GetInsertBlock()->getModule(), builder, ii->get_axis());
-    return (Instruction*)offset;
+    Value *result = tgt_->get_block_id(builder.GetInsertBlock()->getModule(), builder, ii->get_axis());
+    return (Instruction*)result;
+  }
+  if(ir::get_num_program_inst* ii = dynamic_cast<ir::get_num_program_inst*>(inst)){
+    Value *result = tgt_->get_num_blocks(builder.GetInsertBlock()->getModule(), builder, ii->get_axis());
+    return (Instruction*)result;
   }
   if(ir::atomic_cas_inst* ii = dynamic_cast<ir::atomic_cas_inst*>(inst)){
     BasicBlock *current = builder.GetInsertBlock();
@@ -331,6 +335,7 @@ Instruction *selection::llvm_inst(ir::instruction *inst, std::function<Value*(ir
     BasicBlock *tid_0_done_bb = BasicBlock::Create(ctx, "tid_0_done", current->getParent());
     Value *ptr = builder.CreateGEP(sh_mem_ptr_, builder.getInt32(alloc_->get_offset(ii)));
     ptr = builder.CreateBitCast(ptr, PointerType::get(builder.getInt32Ty(), ptr->getType()->getPointerAddressSpace()));
+    tgt_->add_memfence(module, builder);
     tgt_->add_barrier(module, builder);
     builder.CreateCondBr(pred, tid_0_bb, tid_0_done_bb);
     builder.SetInsertPoint(tid_0_bb);
@@ -342,10 +347,29 @@ Instruction *selection::llvm_inst(ir::instruction *inst, std::function<Value*(ir
     builder.CreateStore(old, ptr);
     builder.CreateBr(tid_0_done_bb);
     builder.SetInsertPoint(tid_0_done_bb);
+    tgt_->add_memfence(module, builder);
     tgt_->add_barrier(module, builder);
     Value *res = builder.CreateLoad(ptr);
     return (Instruction*)res;
   }
+  if(ir::atomic_exch_inst* ii = dynamic_cast<ir::atomic_exch_inst*>(inst)){
+    BasicBlock *current = builder.GetInsertBlock();
+    Module *module = current->getModule();
+    Value *rmw_ptr = value(ii->get_operand(0));
+    Value *rmw_val = value(ii->get_operand(1));
+    Value *tid = tgt_->get_local_id(module, builder, 0);
+    Value *pred = builder.CreateICmpEQ(tid, builder.getInt32(0));
+    BasicBlock *tid_0_bb = BasicBlock::Create(ctx, "tid_0", current->getParent());
+    BasicBlock *tid_0_done_bb = BasicBlock::Create(ctx, "tid_0_done", current->getParent());
+    tgt_->add_memfence(module, builder);
+    tgt_->add_barrier(module, builder);
+    builder.CreateCondBr(pred, tid_0_bb, tid_0_done_bb);
+    builder.SetInsertPoint(tid_0_bb);
+    Value *res = builder.CreateAtomicRMW(AtomicRMWInst::Xchg, rmw_ptr, rmw_val, AtomicOrdering::Monotonic, SyncScope::System);
+    builder.CreateBr(tid_0_done_bb);
+    builder.SetInsertPoint(tid_0_done_bb);
+    return (Instruction*)res;
+  }
   if(ir::atomic_add_inst* ii = dynamic_cast<ir::atomic_add_inst*>(inst)){
     Value *ptr = value(ii->get_operand(0));
     Value *val = value(ii->get_operand(1));
@@ -1136,17 +1160,17 @@ void selection::lower_tile_instruction(ir::instruction *ins, llvm::IRBuilder<> &
           Value *result_then = builder.CreateLoad(ptr);
           builder.CreateBr(mask_done_bb);
           builder.SetInsertPoint(mask_done_bb);
-          Value *result = nullptr;
+          Value *current_result = nullptr;
           if(false_values){
-            result = builder.CreatePHI(result_then->getType(), 2);
-            ((PHINode*)result)->addIncoming(result_then, mask_then_bb);
+            current_result = builder.CreatePHI(result_then->getType(), 2);
+            ((PHINode*)current_result)->addIncoming(result_then, mask_then_bb);
             Value *result_false = false_values->get_value(idx);
-            if(vector_size > 1)
+            if(result_then->getType()->isVectorTy())
               result_false = builder.CreateVectorSplat(vector_size, result_false);
-            ((PHINode*)result)->addIncoming(result_false, current_bb);
+            ((PHINode*)current_result)->addIncoming(result_false, current_bb);
           }
           else
-            result = result_then;
+            current_result = result_then;
 
 //          std::string offset = "";
 //          if(cst)
@@ -1160,7 +1184,7 @@ void selection::lower_tile_instruction(ir::instruction *ins, llvm::IRBuilder<> &
 //          InlineAsm *iasm = InlineAsm::get(ty, asm_str, "b,=r,=r,=r,=r,l", true);
 //          Value *result = builder.CreateCall(iasm, {mask, ptr});
 
-          packets[id] = result;
+          packets[id] = current_result;
         }
       });
       // extract result element
diff --git a/lib/codegen/target.cpp b/lib/codegen/target.cpp
index 2e20839d9..4116bcca7 100644
--- a/lib/codegen/target.cpp
+++ b/lib/codegen/target.cpp
@@ -32,6 +32,11 @@ Value* amd_cl_target::get_global_offset(Module *module, IRBuilder<>& builder, un
   return result;
 }
 
+Instruction* amd_cl_target::add_memfence(Module *module, IRBuilder<>& builder) {
+  throw std::runtime_error("not implemented");
+}
+
+
 Value* amd_cl_target::get_block_id(Module *module, IRBuilder<>& builder, unsigned ax) {
   static std::array<Intrinsic::ID, 3> ids = {
     Intrinsic::amdgcn_workgroup_id_x,
@@ -43,6 +48,16 @@ Value* amd_cl_target::get_block_id(Module *module, IRBuilder<>& builder, unsigne
   return group_id;
 }
 
+Value* amd_cl_target::get_num_blocks(Module *module, IRBuilder<>& builder, unsigned ax) {
+  static std::array<Intrinsic::ID, 3> ids = {
+    Intrinsic::r600_read_ngroups_x,
+    Intrinsic::r600_read_ngroups_y,
+    Intrinsic::r600_read_ngroups_z
+  };
+  Value* get_num_group = Intrinsic::getDeclaration(module, ids[ax]);
+  return builder.CreateCall(get_num_group, {});
+}
+
 Value* amd_cl_target::get_local_id(Module *module, IRBuilder<>& builder, unsigned ax) {
   static std::array<Intrinsic::ID, 3> ids = {
     Intrinsic::amdgcn_workitem_id_x,
@@ -70,6 +85,12 @@ Instruction* nvidia_cu_target::add_barrier(Module *module, IRBuilder<>& builder)
   return builder.CreateCall(barrier, {});
 }
 
+Instruction* nvidia_cu_target::add_memfence(Module *module, IRBuilder<>& builder) {
+  Function *barrier = Intrinsic::getDeclaration(module, Intrinsic::nvvm_membar_gl);
+  return builder.CreateCall(barrier, {});
+}
+
+
 Value* nvidia_cu_target::get_global_offset(Module *module, IRBuilder<>& builder, unsigned stride, unsigned ax) {
   Value* group_id = get_block_id(module, builder, ax);
   Value* result = builder.CreateMul(builder.getInt32(stride), group_id);
@@ -82,39 +103,39 @@ Value* nvidia_cu_target::get_block_id(Module *module, IRBuilder<>& builder, unsi
     Intrinsic::nvvm_read_ptx_sreg_ctaid_y,
     Intrinsic::nvvm_read_ptx_sreg_ctaid_z
   };
-  bool z_order = true;
-  if(z_order && ax < 2){
-    static std::array<Intrinsic::ID, 3> n_cta_ids = {
-      Intrinsic::nvvm_read_ptx_sreg_nctaid_x,
-      Intrinsic::nvvm_read_ptx_sreg_nctaid_y,
-      Intrinsic::nvvm_read_ptx_sreg_nctaid_z
-    };
-    Value* cta_id_0 = builder.CreateIntrinsic(cta_ids[0], {}, {});
-    Value* cta_id_1 = builder.CreateIntrinsic(cta_ids[1], {}, {});
-    Value* n_cta_id_0 = builder.CreateIntrinsic(n_cta_ids[0], {}, {});
-    Value* n_cta_id_1 = builder.CreateIntrinsic(n_cta_ids[1], {}, {});
-    // global block ID
-    Value* bid = builder.CreateAdd(cta_id_0, builder.CreateMul(cta_id_1, n_cta_id_0));
-    // helper for minimum
-    auto Min = [&](Value *x, Value *y){
-      return builder.CreateSelect(builder.CreateICmpSGE(x, y), y, x);
-    };
-    // super-tile size
-    Value* sts = Min(builder.getInt32(16), n_cta_id_1);
-    // number of CTAs per super-block
-    Value *nscta = builder.CreateMul(n_cta_id_0, sts);
-    Value *bid0 = builder.CreateURem(builder.CreateUDiv(bid, sts), n_cta_id_0);
-    Value *bid1 = builder.CreateAdd(builder.CreateMul(builder.CreateUDiv(bid, nscta), sts),builder.CreateURem(bid, sts));
-    if(ax == 0)
-      return bid0;
-    else
-      return bid1;
-  }
-  else{
+//  bool z_order = true;
+//  if(z_order && ax < 2){
+//    static std::array<Intrinsic::ID, 3> n_cta_ids = {
+//      Intrinsic::nvvm_read_ptx_sreg_nctaid_x,
+//      Intrinsic::nvvm_read_ptx_sreg_nctaid_y,
+//      Intrinsic::nvvm_read_ptx_sreg_nctaid_z
+//    };
+//    Value* cta_id_0 = builder.CreateIntrinsic(cta_ids[0], {}, {});
+//    Value* cta_id_1 = builder.CreateIntrinsic(cta_ids[1], {}, {});
+//    Value* n_cta_id_0 = builder.CreateIntrinsic(n_cta_ids[0], {}, {});
+//    Value* n_cta_id_1 = builder.CreateIntrinsic(n_cta_ids[1], {}, {});
+//    // global block ID
+//    Value* bid = builder.CreateAdd(cta_id_0, builder.CreateMul(cta_id_1, n_cta_id_0));
+//    // helper for minimum
+//    auto Min = [&](Value *x, Value *y){
+//      return builder.CreateSelect(builder.CreateICmpSGE(x, y), y, x);
+//    };
+//    // super-tile size
+//    Value* sts = Min(builder.getInt32(16), n_cta_id_1);
+//    // number of CTAs per super-block
+//    Value *nscta = builder.CreateMul(n_cta_id_0, sts);
+//    Value *bid0 = builder.CreateURem(builder.CreateUDiv(bid, sts), n_cta_id_0);
+//    Value *bid1 = builder.CreateAdd(builder.CreateMul(builder.CreateUDiv(bid, nscta), sts),builder.CreateURem(bid, sts));
+//    if(ax == 0)
+//      return bid0;
+//    else
+//      return bid1;
+//  }
+//  else{
     Value* get_cta_id = Intrinsic::getDeclaration(module, cta_ids[ax]);
     Value* cta_id = builder.CreateCall(get_cta_id, {});
     return cta_id;
-  }
+//  }
 }
 
 Value* nvidia_cu_target::get_local_id(Module *module, IRBuilder<>& builder, unsigned ax) {
@@ -127,6 +148,16 @@ Value* nvidia_cu_target::get_local_id(Module *module, IRBuilder<>& builder, unsi
   return builder.CreateCall(get_local_id, {});
 }
 
+Value* nvidia_cu_target::get_num_blocks(Module *module, IRBuilder<>& builder, unsigned ax) {
+  static std::array<Intrinsic::ID, 3> ids = {
+    Intrinsic::nvvm_read_ptx_sreg_nctaid_x,
+    Intrinsic::nvvm_read_ptx_sreg_nctaid_y,
+    Intrinsic::nvvm_read_ptx_sreg_nctaid_z
+  };
+  Value* get_nctaid = Intrinsic::getDeclaration(module, ids[ax]);
+  return builder.CreateCall(get_nctaid, {});
+}
+
 // CPU
 
 void cpu_target::set_kernel(IRBuilder<>& builder, LLVMContext &ctx, Module *module, Function* fn) {
@@ -138,6 +169,12 @@ Instruction* cpu_target::add_barrier(Module *module, IRBuilder<>& builder) {
   return (Instruction*)builder.CreateAdd(builder.getInt32(0), builder.getInt32(0));
 }
 
+Instruction* cpu_target::add_memfence(Module *module, IRBuilder<>& builder) {
+  // no barrier on CPU
+  return (Instruction*)builder.CreateAdd(builder.getInt32(0), builder.getInt32(0));
+}
+
+
 Value* cpu_target::get_block_id(Module *module, llvm::IRBuilder<> &builder, unsigned ax) {
   const Function *fn = builder.GetInsertBlock()->getParent();
   size_t num_params = fn->getFunctionType()->getNumParams();
@@ -149,6 +186,11 @@ Value* cpu_target::get_block_id(Module *module, llvm::IRBuilder<> &builder, unsi
   return (Argument*)ids[ax];
 }
 
+Value* cpu_target::get_num_blocks(Module *module, IRBuilder<>& builder, unsigned ax) {
+  throw std::runtime_error("not implemented");
+}
+
+
 Value* cpu_target::get_global_offset(Module *module, IRBuilder<>& builder, unsigned stride, unsigned ax) {
   Value* result = builder.CreateMul(builder.getInt32(stride), get_block_id(module, builder, ax));
   return result;
diff --git a/lib/dnn/base.cpp b/lib/dnn/base.cpp
index 72e0d340e..e5aa7ad45 100644
--- a/lib/dnn/base.cpp
+++ b/lib/dnn/base.cpp
@@ -6,6 +6,8 @@
 namespace triton{
 namespace dnn{
 
+namespace rt = triton::runtime;
+
 
 void base::set_ld(const std::vector<int32_t>& shapes,
                   std::vector<int32_t>& ld) {
@@ -28,8 +30,7 @@ params_t base::heuristics() const {
   return *search_space().begin();
 }
 
-void base::enqueue(driver::stream *stream, std::vector<driver::buffer *> args, autotuning_t autotune) {
-  namespace rt = triton::runtime;
+std::pair<base*, rt::jit*> base::get_profile_impl(driver::stream *stream, std::vector<driver::buffer *> args, autotuning_t autotune) {
   static std::map<base*, std::unique_ptr<rt::jit>, cmp_recompile> m_jit;
   driver::context* ctx = stream->context();
   rt::jit* jit;
@@ -67,16 +68,23 @@ void base::enqueue(driver::stream *stream, std::vector<driver::buffer *> args, a
     clone->init_impl(stream, (triton::driver::cu_module*)kernel->module());
   }
   /* retrieved compiled template */
-  else{
+  else {
     jit = m_jit.at(this).get();
   }
-
-  /* get launch parameters */
-  driver::kernel* kernel = jit->get_function(name_.c_str());
-  rt::launch_information info = jit->get_launch_info(name_.c_str());
-  /* launch */
   auto it = m_jit.find(this);
-  it->first->enqueue_impl(stream, kernel, args, info);
+  return {it->first, jit};
+}
+
+void base::enqueue(driver::stream *stream, std::vector<driver::buffer *> args, autotuning_t autotune) {
+  launch_context_t info = get_launch_context(stream, args, autotune);
+  info.op->enqueue_impl(stream, info.kernel, args, info.info);
+}
+
+launch_context_t base::get_launch_context(driver::stream *stream, std::vector<driver::buffer *> args, autotuning_t autotune) {
+  std::pair<base*, rt::jit*> profile = get_profile_impl(stream, args, autotune);
+  driver::kernel* kernel = profile.second->get_function(name_.c_str());
+  rt::launch_information info = profile.second->get_launch_info(name_.c_str());
+  return {profile.first, kernel, info};
 }
 
 }
diff --git a/lib/dnn/blocksparse/dot.cpp b/lib/dnn/blocksparse/dot.cpp
index 9ddb2514b..46a706498 100644
--- a/lib/dnn/blocksparse/dot.cpp
+++ b/lib/dnn/blocksparse/dot.cpp
@@ -13,26 +13,42 @@ bool dot::operator <(const base& other) const {
   auto *y = dynamic_cast<const dot*>(&other);
   if(!y)
     return true;
-  return  std::tie(M_, N_, K_)
-        < std::tie(y->M_, y->N_, y->K_);
+  return  std::tie(N_, S_, C_, BS_, nlocks_, ab_ty_, c_ty_)
+        < std::tie(y->N_, y->S_, y->C_, y->BS_, y->nlocks_, y->ab_ty_, y->c_ty_);
 }
 
 std::vector<params_t> dot::search_space() const {
-
+  throw std::runtime_error("not implemented");
 }
 
 params_t dot::heuristics() const {
-
+  throw std::runtime_error("not implemented");
 }
 
 base * dot::clone() const {
   return new dot(*this);
 }
 
-dot::dot(int32_t M, int32_t N, int32_t K):
-    base("bsdot"), M_(M), N_(N), K_(K) {
-  ab_ty_ = "fp32";
-  c_ty_ = "fp32";
+dot::dot(int32_t N, int32_t K, int32_t S, int32_t C,
+         const std::string& ty, int32_t BS, int32_t nlocks):
+    base("bsdot"),
+    N_(N), K_(K), S_(S), C_(C),
+    ab_ty_(ty), c_ty_(ty),
+    BS_(BS), nlocks_(nlocks) {
+}
+
+void dot::init_impl(driver::stream *stream, driver::cu_module *module) {
+//  int32_t TM = info.globals["TM"];
+//  size_t grid_0 = (N_ + TM - 1) / TM;
+//  if(nlocks_){
+//    locks_ = triton::driver::buffer::create(stream->context(), grid_0 * nlocks_ * 2 * 4);
+//    ((driver::cu_buffer*)locks_)->set_zero(stream, grid_0 * nlocks_ * 2 * 4);
+//  }
+}
+
+void dot::deinit_impl() {
+//  if(locks_)
+//    delete locks_;
 }
 
 void dot::enqueue_impl(driver::stream *stream, driver::kernel *kernel,
@@ -41,64 +57,89 @@ void dot::enqueue_impl(driver::stream *stream, driver::kernel *kernel,
   driver::buffer *b = args[1];
   driver::buffer *c = args[2];
   driver::buffer *lut = args[3];
-  int32_t lda = M_;
-  int32_t ldc = M_;
+  driver::buffer *locks = args[4];
+  int32_t lda = N_;
+  int32_t ldc = N_;
   kernel->setArg(0, a);
   kernel->setArg(1, b);
   kernel->setArg(2, c);
   kernel->setArg(3, lda);
   kernel->setArg(4, ldc);
-  kernel->setArg(5, lut);
+  kernel->setArg(5, N_);
+  kernel->setArg(6, lut);
+  kernel->setArg(7, locks);
+  kernel->setArg(8, nlocks_);
   int32_t TM = info.globals["TM"];
-  int32_t TN = info.globals["TN"];
-  size_t grid_0 = (M_ + TM - 1) / TM;
-  size_t grid_1 = (N_ + TN - 1) / TN;
+  size_t grid_0 = (N_ + TM - 1) / TM;
+  size_t grid_1 = S_;
+  std::cout << N_ << " " << grid_0 << std::endl;
+  if(nlocks_){
+//    locks_ = triton::driver::buffer::create(stream->context(), grid_0 * nlocks_ * 2 * 4);
+    ((driver::cu_buffer*)locks)->set_zero(stream, grid_0 * nlocks_ * 2 * 4);
+  }
   stream->enqueue(kernel, {grid_0, grid_1, 1}, {info.num_threads, 1, 1});
-  stream->synchronize();
 }
 
 void dot::triton_c_src(std::ostream &os) const {
   std::string result =
 
   R"(
-  const tunable int32 TM = {64, 128};
-  const tunable int32 TN = {32};
-  const tunable int32 TK = {32};
+  const tunable int32 TM = {64};
+  const tunable int32 TN = {)" + std::to_string(BS_) + R"(};
+  const tunable int32 TK = {)" + std::to_string(BS_) + R"(};
 
   void bsdot(restrict read_only align(16) )" + ab_ty_ + R"( *A,
               restrict read_only align(16) )" + ab_ty_ + R"( *B,
-              fp32* C,
-              int32 lda, int32 ldc,
-              int32* lut_base){
+              )" + c_ty_ + R"(* C,
+              int32 lda, int32 ldc, int32 N,
+              int32* lut, int32* locks, int32 nlocks){
     int32 ridx = get_range_id(0);
     int32 ridy = get_range_id(1);
-    fp32 c[TM, TN] = 0;
-    int32 rka[TK] = 0 ... TK;
-    int32 rkb[TK] = 0 ... TK;
+    fp32 acc[TM, TN] = 0;
     int32 rxa[TM] = ridx * TM + (0 ... TM);
     int32 ryb[TN] = 0 ... TN;
+    int32 rka[TK] = 0 ... TK;
+    int32 rkb[TK] = 0 ... TK;
     int32 offa[TM, TK] = rxa[:, newaxis] + rka[newaxis, :]*lda;
     int32 offb[TK, TN] = ryb[newaxis, :] + rkb[:, newaxis]*TK;
-    int32 *header = lut_base + ridy * 4;
+    int32 *header = lut + ridy * 4;
     int32 offset = *(header + 0);
     int32 K      = *(header + 1);
-    int32 h2     = *(header + 2);
-    int32 h3     = *(header + 3);
-    int32 *lut   = lut_base + offset*2;
+    int32 column = *(header + 2);
+    int32 lockid   = *(header + 3);
+    int32 *plut   = lut + offset * 2;
     for(int32 k = K; k > 0; k = k - 1){
-       int32 ak = *(lut + 0);
-       int32 bk = *(lut + 1);
-       fp32* pa[TM, TK] = A + offa + ak * TK * lda;
-       fp32* pb[TK, TN] = B + offb + bk * TK * TN;
-       fp32 a[TM, TK] = *pa;
-       fp32 b[TK, TN] = *pb;;
-       c = dot(a, b, c);
-       lut = lut + 2;
+       int32 ak = *(plut + 0);
+       int32 bk = *(plut + 1);
+       )" + ab_ty_ + R"(* pa[TM, TK] = A + offa + ak * TK * lda;
+       )" + ab_ty_ + R"(* pb[TK, TN] = B + offb + bk * TK * TN;
+       )" + ab_ty_ + R"( a[TM, TK] = *pa;
+       )" + ab_ty_ + R"( b[TK, TN] = *pb;
+       acc = dot(a, b, acc);
+       plut = plut + 2;
     }
     int32 rxc[TM] = ridx * TM + (0 ... TM);
-    int32 ryc[TN] = ridy * TN + (0 ... TN);
-    fp32* pc[TM, TN] = C + rxc[:, newaxis] + ryc[newaxis, :]*ldc;
-    *pc = c;
+    int32 ryc[TN] = column * TN + (0 ... TN);
+    )" + c_ty_ + R"(" c[TM, TN] = acc;
+    )" + c_ty_ + R"(* pc[TM, TN] = C + rxc[:, newaxis] + ryc[newaxis, :]*ldc;
+    int1 checkc[TM, TN] = (rxc < N)[:, newaxis];
+    if(lockid == 0){
+      @checkc *pc = c;
+    }
+    else{
+      int32 *plock = locks + ridx*nlocks + lockid - 1;
+      int32 *pcount = plock + get_num_program(0)*nlocks;
+      while(__atomic_cas(plock, 0, 1));
+      int32 count = *pcount;
+      if(count == 0) {
+        @checkc *pc = c;
+      }
+      else {
+        @checkc *pc = c + *pc;
+      }
+      *pcount = 1;
+      __atomic_exch(plock, 0);
+    }
   })";
 
   os << result;
diff --git a/lib/ir/builder.cpp b/lib/ir/builder.cpp
index e58fd9924..77c099827 100644
--- a/lib/ir/builder.cpp
+++ b/lib/ir/builder.cpp
@@ -294,10 +294,18 @@ value *builder::create_get_range_id(unsigned axis, const std::string &name) {
   return insert(get_range_id_inst::create(ctx_, axis, name));
 }
 
+value *builder::create_get_num_program(unsigned axis, const std::string &name) {
+  return insert(get_num_program_inst::create(ctx_, axis, name));
+}
+
 value *builder::create_atomic_cas(value *ptr, value *cmp, value *val, const std::string &name){
   return insert(atomic_cas_inst::create(ptr, cmp, val, name));
 }
 
+value *builder::create_atomic_exch(value *ptr, value *val, const std::string &name){
+  return insert(atomic_exch_inst::create(ptr, val, name));
+}
+
 value *builder::create_atomic_add(value *ptr, value *val, const std::string &name){
   return insert(atomic_add_inst::create(ptr, val, name));
 }
diff --git a/lib/ir/instructions.cpp b/lib/ir/instructions.cpp
index 9537336fb..a29c11914 100644
--- a/lib/ir/instructions.cpp
+++ b/lib/ir/instructions.cpp
@@ -636,6 +636,17 @@ instruction* get_range_id_inst::create(context &ctx, unsigned axis, const std::s
   return new get_range_id_inst(type::get_int32_ty(ctx), axis, name, next);
 }
 
+// get_num_program
+get_num_program_inst::get_num_program_inst(type *ty, unsigned axis, const std::string &name, instruction *next)
+  : builtin_inst(ty, 0, 1, name, next), axis_(axis){
+
+}
+
+instruction* get_num_program_inst::create(context &ctx, unsigned axis, const std::string &name, instruction *next) {
+  return new get_num_program_inst(type::get_int32_ty(ctx), axis, name, next);
+}
+
+
 // atomic cas
 
 atomic_cas_inst::atomic_cas_inst(value *ptr, value *cmp, value *val, const std::string &name, instruction *next)
@@ -649,6 +660,18 @@ instruction* atomic_cas_inst::create(value *ptr, value *cmp, value *val, const s
   return new atomic_cas_inst(ptr, cmp, val, name, next);
 }
 
+// atomic exch
+
+atomic_exch_inst::atomic_exch_inst(value *ptr, value *val, const std::string &name, instruction *next)
+  : builtin_inst(ptr->get_type()->get_pointer_element_ty(), 2, 1, name, next) {
+  set_operand(0, ptr);
+  set_operand(1, val);
+}
+
+instruction* atomic_exch_inst::create(value *ptr, value *val, const std::string &name, instruction *next) {
+  return new atomic_exch_inst(ptr, val, name, next);
+}
+
 // atomic add
 
 atomic_add_inst::atomic_add_inst(value *ptr, value *val, const std::string &name, instruction *next)
diff --git a/lib/lang/expression.cpp b/lib/lang/expression.cpp
index 6baa1f3b2..15e66607a 100644
--- a/lib/lang/expression.cpp
+++ b/lib/lang/expression.cpp
@@ -120,6 +120,11 @@ ir::value* get_range_id_expression::codegen(ir::module *mod) const {
   return mod->get_builder().create_get_range_id(axis_->value());
 }
 
+// get_num_program
+ir::value* get_num_program_expression::codegen(ir::module *mod) const {
+  return mod->get_builder().create_get_num_program(axis_->value());
+}
+
 // atomic cas
 ir::value* atomic_cas_expression::codegen(ir::module *mod) const {
   ir::value *ptr = ptr_->codegen(mod);
@@ -128,6 +133,13 @@ ir::value* atomic_cas_expression::codegen(ir::module *mod) const {
   return mod->get_builder().create_atomic_cas(ptr, cmp, val);
 }
 
+// atomic exch
+ir::value* atomic_exch_expression::codegen(ir::module *mod) const {
+  ir::value *ptr = ptr_->codegen(mod);
+  ir::value *val = val_->codegen(mod);
+  return mod->get_builder().create_atomic_exch(ptr, val);
+}
+
 // atomic add
 ir::value* atomic_add_expression::codegen(ir::module *mod) const {
   ir::value *ptr = ptr_->codegen(mod);