diff --git a/include/triton/codegen/selection/generator.h b/include/triton/codegen/selection/generator.h
index 6df877486..f13a3305b 100644
--- a/include/triton/codegen/selection/generator.h
+++ b/include/triton/codegen/selection/generator.h
@@ -112,6 +112,7 @@ public:
   void visit_downcast_inst(ir::downcast_inst*);
 
   void visit_exp_inst(ir::exp_inst*);
+  void visit_log_inst(ir::log_inst*);
 
   void visit_get_program_id_inst(ir::get_program_id_inst*);
   void visit_get_num_program_inst(ir::get_num_program_inst*);
diff --git a/include/triton/ir/builder.h b/include/triton/ir/builder.h
index f204ee0b5..7a7ef80bc 100644
--- a/include/triton/ir/builder.h
+++ b/include/triton/ir/builder.h
@@ -138,6 +138,7 @@ public:
   value *create_atomic_exch(value *ptr, value *val, const std::string &name = "");
   value *create_atomic_add(value *ptr, value *val, value *msk, const std::string &name = "");
   value *create_exp(value* arg, const std::string &name = "");
+  value *create_log(value* arg, const std::string &name = "");
   value *create_dot(value *A, value *B, value *C, const std::string &name = "");
   value *create_trans(value *A, const std::vector<int> &perm = {}, const std::string &name = "");
   value *create_sqrt(value *A, const std::string &name = "");
diff --git a/include/triton/ir/enums.h b/include/triton/ir/enums.h
index 10b017919..86e4b925f 100644
--- a/include/triton/ir/enums.h
+++ b/include/triton/ir/enums.h
@@ -129,6 +129,7 @@ enum value_id_t: unsigned {
   INST_ATOMIC_ADD,
   // math
   INST_EXP,
+  INST_LOG,
   // array arithmetic
   INST_TRANS,
   INST_REDUCE,
diff --git a/include/triton/ir/instructions.h b/include/triton/ir/instructions.h
index 83255d215..755fb172d 100644
--- a/include/triton/ir/instructions.h
+++ b/include/triton/ir/instructions.h
@@ -623,6 +623,18 @@ public:
   static instruction* create(value *val, const std::string &name = "", instruction *next = nullptr);
 };
 
+class log_inst: public builtin_inst {
+private:
+  log_inst(value *val, const std::string &name = "", instruction *next = nullptr);
+  std::string repr_impl() const { return "log"; }
+  _TRITON_DEFINE_CLONE(log_inst)
+  _TRITON_DEFINE_ACCEPT(log_inst)
+
+public:
+  static instruction* create(value *val, const std::string &name = "", instruction *next = nullptr);
+};
+
+
 class dot_inst: public builtin_inst {
 public:
   enum TransT { NoTrans, Trans };
diff --git a/include/triton/ir/visitor.h b/include/triton/ir/visitor.h
index e53331af4..e612ee889 100644
--- a/include/triton/ir/visitor.h
+++ b/include/triton/ir/visitor.h
@@ -49,6 +49,7 @@ class broadcast_inst;
 class downcast_inst;
 
 class exp_inst;
+class log_inst;
 
 class get_program_id_inst;
 class get_num_program_inst;
@@ -117,6 +118,7 @@ public:
   virtual void visit_masked_store_inst(masked_store_inst*) = 0;
 
   virtual void visit_exp_inst(exp_inst*) = 0;
+  virtual void visit_log_inst(log_inst*) = 0;
 
   virtual void visit_reshape_inst(reshape_inst*) = 0;
   virtual void visit_splat_inst(splat_inst*) = 0;
diff --git a/include/triton/lang/token.h b/include/triton/lang/token.h
index 621c555fb..e4cb22c0d 100644
--- a/include/triton/lang/token.h
+++ b/include/triton/lang/token.h
@@ -167,6 +167,7 @@ public:
     // function keywords
     BITCAST,
     EXP,
+    LOG,
     // KEYWORD END
 
     IDENTIFIER,
diff --git a/lib/codegen/selection/generator.cc b/lib/codegen/selection/generator.cc
index 3de7b2c99..18f2dafcd 100644
--- a/lib/codegen/selection/generator.cc
+++ b/lib/codegen/selection/generator.cc
@@ -598,7 +598,7 @@ void generator::visit_exp_inst(ir::exp_inst* x){
   Constant *log2e = ConstantFP::get(builder_->getFloatTy(), 1.4426950408889634);
   std::vector<llvm::Type*> tys = {builder_->getFloatTy()};
   FunctionType *fn_ty = FunctionType::get(builder_->getFloatTy(), tys, false);
-  InlineAsm *ex2 = InlineAsm::get(fn_ty, "ex2.approx.ftz.f32 $0, $1;", "=f,f", false);
+  InlineAsm *ex2 = InlineAsm::get(fn_ty, "ex2.approx.f32 $0, $1;", "=f,f", false);
 
 
   for_each(x, [&](indices_t idx){
@@ -607,6 +607,24 @@ void generator::visit_exp_inst(ir::exp_inst* x){
   });
 }
 
+void generator::visit_log_inst(ir::log_inst* x){
+  distributed_tile *arg = (distributed_tile*)tmap_.at(x->get_operand(0));
+//  Function *fn = builder_->GetInsertBlock()->getParent();
+//  Module *module = fn->getParent();
+//  Type *ty = llvm_type(x->get_type()->get_scalar_ty(), *ctx_);
+//  Function *ex2 = Intrinsic::getDeclaration(module, Intrinsic::nvvm_ex2_approx_ftz_f, {ty});
+  Constant *rcplog2e = ConstantFP::get(builder_->getFloatTy(), 0.6931471805599453);
+  std::vector<llvm::Type*> tys = {builder_->getFloatTy()};
+  FunctionType *fn_ty = FunctionType::get(builder_->getFloatTy(), tys, false);
+  InlineAsm *lg2 = InlineAsm::get(fn_ty, "lg2.approx.f32 $0, $1;", "=f,f", false);
+
+
+  for_each(x, [&](indices_t idx){
+    Value *lg2arg = builder_->CreateCall(lg2, std::vector<llvm::Value*>{arg->get_value(idx)});
+    set_value(x, idx, builder_->CreateFMul(lg2arg, rcplog2e));
+  });
+}
+
 void generator::visit_atomic_cas_inst(ir::atomic_cas_inst* cas) {
   BasicBlock *current = builder_->GetInsertBlock();
   Module *module = current->getModule();
diff --git a/lib/ir/builder.cc b/lib/ir/builder.cc
index c100f461a..eceb694d2 100644
--- a/lib/ir/builder.cc
+++ b/lib/ir/builder.cc
@@ -315,6 +315,10 @@ value *builder::create_exp(value *arg, const std::string &name){
   return insert(exp_inst::create(arg, name));
 }
 
+value *builder::create_log(value *arg, const std::string &name){
+  return insert(log_inst::create(arg, name));
+}
+
 value *builder::create_dot(value *A, value *B, value *C, const std::string &name) {
   return insert(dot_inst::create_nn(A, B, C, name));
 }
diff --git a/lib/ir/instructions.cc b/lib/ir/instructions.cc
index 6ede70001..828d7081e 100644
--- a/lib/ir/instructions.cc
+++ b/lib/ir/instructions.cc
@@ -758,6 +758,17 @@ instruction* exp_inst::create(value *val, const std::string& name, instruction *
   return new exp_inst(val, name, next);
 }
 
+// log
+
+log_inst::log_inst(value *val, const std::string &name, instruction *next)
+  : builtin_inst(val->get_type(), INST_LOG, 1, name, next) {
+  set_operand(0, val);
+}
+
+instruction* log_inst::create(value *val, const std::string& name, instruction *next) {
+  return new log_inst(val, name, next);
+}
+
 
 //===----------------------------------------------------------------------===//
 //                               intrinsic instructions
diff --git a/lib/lang/ast.cc b/lib/lang/ast.cc
index c0887574b..0dfce31c8 100644
--- a/lib/lang/ast.cc
+++ b/lib/lang/ast.cc
@@ -656,6 +656,7 @@ void UnaryOp::TypeChecking() {
     return ReduceOpTypeChecking();
 
   case Token::EXP:
+  case Token::LOG:
     return IntrinsicOpTypeChecking();
 
   default:
diff --git a/lib/lang/code_gen.cc b/lib/lang/code_gen.cc
index 323808ac7..823062d45 100644
--- a/lib/lang/code_gen.cc
+++ b/lib/lang/code_gen.cc
@@ -203,6 +203,7 @@ void Generator::VisitUnaryOp(UnaryOp* unary) {
     case Token::BITCAST:     return set_ret(GenBitCastOp(arg, GenIRType(unary->Type(), *ctx_)));
     case Token::CAST:        return set_ret(GenSemCastOp(arg, GenIRType(unary->Type(), *ctx_)));
     case Token::EXP:         return set_ret(bld_->create_exp(arg)); //FIXME cast
+    case Token::LOG:         return set_ret(bld_->create_log(arg));
     case Token::REDUCE: {
       int ax, tag;
       UnaryOp::decodeRed(unary->info_, ax, tag);
@@ -277,7 +278,10 @@ void Generator::VisitFuncCall(FuncCall* funcCall) {
     ir::value* val = ret_;
     return set_ret(bld_->create_atomic_exch(ptr, val));
   }
-  if(name == "f32_atomic_add" || name == "atomic_add_64x64"){
+  if(name == "f32_atomic_add" || 
+     name == "atomic_add_32x32" || name == "atomic_add_32x64" || name == "atomic_add_32x128" ||
+     name == "atomic_add_64x32" || name == "atomic_add_64x64" || name == "atomic_add_64x128" ||
+     name == "atomic_add_128x32"|| name == "atomic_add_128x64"|| name == "atomic_add_128x128"){
     VisitExpr(funcCall->Args()->at(0));
     ir::value* ptr = ret_;
     VisitExpr(funcCall->Args()->at(1));
diff --git a/lib/lang/parser.cc b/lib/lang/parser.cc
index 8025ca563..adb22b405 100644
--- a/lib/lang/parser.cc
+++ b/lib/lang/parser.cc
@@ -571,6 +571,7 @@ Expr* Parser::ParseUnaryExpr() {
   case Token::INC: return ParsePrefixIncDec(tok);
   case Token::DEC: return ParsePrefixIncDec(tok);
   case Token::EXP: return ParseUnaryIntrinsicOp(tok, Token::EXP); //FIXME: merge into generic array functions
+  case Token::LOG: return ParseUnaryIntrinsicOp(tok, Token::LOG); //FIXME: merge into generic array functions
   case '&': return ParseUnaryOp(tok, Token::ADDR);
   case '*': return ParseDerefOp(tok);
   case '+': return ParseUnaryOp(tok, Token::PLUS);
diff --git a/lib/lang/token.cc b/lib/lang/token.cc
index d158062e8..aabbd134c 100644
--- a/lib/lang/token.cc
+++ b/lib/lang/token.cc
@@ -46,6 +46,7 @@ const std::unordered_map<std::string, int> Token::kwTypeMap_ {
   { "while", Token::WHILE },
   { "bitcast", Token::BITCAST },
   { "exp", Token::EXP },
+  { "log", Token::LOG },
   { "_Alignas", Token::ALIGNAS },
   { "_Alignof", Token::ALIGNOF },
   { "_Atomic", Token::ATOMIC },
@@ -149,6 +150,7 @@ const std::unordered_map<int, const char*> Token::tagLexemeMap_ {
   { Token::WHILE, "while" },
   { Token::BITCAST, "bitcast" },
   { Token::EXP, "exp" },
+  { Token::LOG, "log" },
   { Token::ALIGNAS, "_Alignas" },
   { Token::ALIGNOF, "_Alignof" },
   { Token::ATOMIC, "_Atomic" },
diff --git a/lib/runtime/function.cc b/lib/runtime/function.cc
index a7f25168b..e4109b628 100644
--- a/lib/runtime/function.cc
+++ b/lib/runtime/function.cc
@@ -311,7 +311,7 @@ function::caller* function::autotune(driver::stream* stream, const grid_fn_ty& g
   // fast path -- no autotuning necessary
   if(callers_.size() == 1)
     return &*callers_.begin()->second;
-  // TODO" copy buffer argument so that auto-tuning doesn't corrupt data
+  // run auto-tuner
   double best_ts = INFINITY;
   caller* ret = nullptr;
   for(auto &x : callers_){
@@ -354,8 +354,15 @@ std::string function::preheader() {
 #define EVALUATOR(a, b, _)  PASTER(a, b, _)
 #define atomic_add(TM, TN) EVALUATOR(atomic_add, EVALUATOR(TM, TN, x), _)
 extern void atomic_add_64(float*[64], float[64], bool[64]);
-extern void atomic_add_128x128(float*[128, 128], float[128, 128], bool[128, 128]);
+extern void atomic_add_32x32(float*[32, 32], float[32, 32], bool[32, 32]);
+extern void atomic_add_32x64(float*[32, 64], float[32, 64], bool[32, 64]);
+extern void atomic_add_32x128(float*[32, 128], float[32, 128], bool[32, 128]);
+extern void atomic_add_64x32(float*[64, 32], float[64, 32], bool[64, 32]);
 extern void atomic_add_64x64(float*[64, 64], float[64, 64], bool[64, 64]);
+extern void atomic_add_64x128(float*[64, 128], float[64, 128], bool[64, 128]);
+extern void atomic_add_128x32(float*[128, 32], float[128, 32], bool[128, 32]);
+extern void atomic_add_128x64(float*[128, 64], float[128, 64], bool[128, 64]);
+extern void atomic_add_128x128(float*[128, 128], float[128, 128], bool[128, 128]);
 
 extern int atomic_cas(int*, int, int);
 extern int atomic_xchg(int*, int);
@@ -416,11 +423,6 @@ void function::operator()(void** args, size_t args_size, const grid_fn_ty& grid_
   // pre-compile kernels
   if(callers_.empty()){
     precompile(stream, opt_);
-    size_t cumsum = 0;
-    for(arg_type ty: callers_.begin()->second->param_tys()){
-      args_off_.push_back(cumsum);
-      cumsum += size_of(ty);
-    }
   }
   // re-tuning key
   cache_key_t key;
diff --git a/python/src/bindings.cc b/python/src/bindings.cc
index c97cf5fc0..ac1c68fc9 100644
--- a/python/src/bindings.cc
+++ b/python/src/bindings.cc
@@ -18,8 +18,6 @@ namespace rt = triton::runtime;
 typedef std::pair<int, int> map_key_t;
 std::map<map_key_t, std::shared_ptr<rt::function::grid_fn_ty>> id_grid_map;
 std::map<map_key_t, std::shared_ptr<rt::function>> id_fn_map;
-std::map<size_t, double> fp64scalar_map;
-std::map<size_t, int64_t> i64scalar_map;
 
 /* Grid utilities */
 
@@ -45,6 +43,7 @@ void delete_fn(const map_key_t& key) {
   id_fn_map.erase(key);
 }
 
+
 void register_cst(const map_key_t& key, const std::string& name, pybind11::buffer& data) {
   pybind11::buffer_info info = data.request();
   id_fn_map[key]->set_cst(name, info.ptr, info.size*info.itemsize);
@@ -53,7 +52,6 @@ void register_cst(const map_key_t& key, const std::string& name, pybind11::buffe
 void cleanup() {
   id_grid_map.clear();
   id_fn_map.clear();
-  i64scalar_map.clear();
 }
 
 size_t make_op_id() {
diff --git a/python/triton/kernel.py b/python/triton/kernel.py
index efd683878..a406b61c3 100644
--- a/python/triton/kernel.py
+++ b/python/triton/kernel.py
@@ -81,8 +81,9 @@ class kernel:
       raise RuntimeError('Must provide grid for kernel launch')
     grid = kwargs['grid']
     libtriton.register_grid((self.op_id, device), grid)
+    # re-allocate buffers for auto-tuning
+    if 'autotune_buf' in kwargs:
+      pass
     # launch
-    #print(self.tys)
     params = pack(self.tys, *[x.data_ptr() if isinstance(x, torch.Tensor) else x for x in args])
-    torch.cuda.synchronize()
     torch.ops.triton.launch_kernel(self.op_id, device, params)
\ No newline at end of file