[Tolk] Peephole optimization: NOT+THROWIFNOT to THROWIF

Author: tolk-vm

tolk-tester/tests/logical-operators.tolk

@@ -351,15 +351,15 @@ These are moments of future optimizations. For now, it's more than enough.
     DUP	//  x x
     IFNOTJMP:<{	//  x
       DROP	//
-      1 PUSHINT	//  '5=1
+      1 PUSHINT	//  '7=1
     }>	//  x
     DUP	//  x x
     IFNOTJMP:<{	//  x
       DROP	//
-      1 PUSHINT	//  '6=1
+      1 PUSHINT	//  '8=1
     }>	//  x
     100 THROWIFNOT
-    -4 PUSHINT	//  '9=-4
+    -4 PUSHINT	//  '11=-4
   }>
 """
 

tolk/optimize.cpp

@@ -399,6 +399,29 @@ bool Optimizer::detect_rewrite_SWAP_STxxxR() {
   return false;
 }
 
+// pattern `NOT` + `123 THROWIFNOT` -> `123 THROWIF` (and THROWIF -> THROWIFNOT)
+bool Optimizer::detect_rewrite_NOT_THROWIF() {
+  bool first_not = op_[0]->is_custom() && op_[0]->op == "NOT";
+  if (!first_not || pb_ < 2 || !op_[1]->is_custom()) {
+    return false;
+  }
+
+  static const char* ends_with[] = {" THROWIF",    " THROWIFNOT"};
+  static const char* repl_with[] = {" THROWIFNOT", " THROWIF"};
+
+  std::string_view f = op_[1]->op;
+  for (size_t i = 0; i < std::size(ends_with); ++i) {
+    if (f.ends_with(ends_with[i])) {
+      p_ = 2;
+      q_ = 1;
+      oq_[0] = std::make_unique<AsmOp>(AsmOp::Custom(op_[0]->loc, op_[1]->op.substr(0, f.rfind(' ')) + repl_with[i], 1, 0));
+      return true;
+    }
+  }
+
+  return false;
+}
+
 bool Optimizer::is_push_const(int* i, int* c) const {
   return pb_ >= 3 && pb_ <= l2_ && tr_[pb_ - 1].is_push_const(i, c);
 }
@@ -821,6 +844,7 @@ bool Optimizer::find_at_least(int pb) {
          detect_rewrite_MY_store_int() || detect_rewrite_MY_skip_bits() || detect_rewrite_NEWC_PUSH_STUR() ||
          detect_rewrite_LDxx_DROP() ||
          detect_rewrite_SWAP_symmetric() || detect_rewrite_SWAP_PUSH_STUR() || detect_rewrite_SWAP_STxxxR() ||
+         detect_rewrite_NOT_THROWIF() ||
          (!(mode_ & 1) &&
           ((is_rot() && rewrite(AsmOp::Custom(loc, "ROT", 3, 3))) || (is_rotrev() && rewrite(AsmOp::Custom(loc, "-ROT", 3, 3))) ||
            (is_2dup() && rewrite(AsmOp::Custom(loc, "2DUP", 2, 4))) ||

tolk/pipe-ast-to-legacy.cpp

@@ -2103,21 +2103,12 @@ static void process_block_statement(V<ast_block_statement> v, CodeBlob& code) {
 }
 
 static void process_assert_statement(V<ast_assert_statement> v, CodeBlob& code) {
-  std::vector<AnyExprV> args(3);
-  if (auto v_not = v->get_cond()->try_as<ast_unary_operator>(); v_not && v_not->tok == tok_logical_not) {
-    args[0] = v->get_thrown_code();
-    args[1] = v->get_cond()->as<ast_unary_operator>()->get_rhs();
-    args[2] = createV<ast_bool_const>(v->loc, true);
-    args[2]->mutate()->assign_inferred_type(TypeDataInt::create());
-  } else {
-    args[0] = v->get_thrown_code();
-    args[1] = v->get_cond();
-    args[2] = createV<ast_bool_const>(v->loc, false);
-    args[2]->mutate()->assign_inferred_type(TypeDataInt::create());
-  }
+  std::vector ir_thrown_code = pre_compile_expr(v->get_thrown_code(), code);
+  std::vector ir_cond = pre_compile_expr(v->get_cond(), code);
+  tolk_assert(ir_cond.size() == 1 && ir_thrown_code.size() == 1);
 
+  std::vector args_vars = { ir_thrown_code[0], ir_cond[0], code.create_int(v->loc, 0, "(assert-0)") };
   FunctionPtr builtin_sym = lookup_function("__throw_if_unless");
-  std::vector<var_idx_t> args_vars = pre_compile_tensor(code, args);
   gen_op_call(code, TypeDataVoid::create(), v->loc, std::move(args_vars), builtin_sym, "(throw-call)");
 }
 

tolk/tolk.h

@@ -906,6 +906,7 @@ struct Optimizer {
   bool detect_rewrite_SWAP_symmetric();
   bool detect_rewrite_SWAP_PUSH_STUR();
   bool detect_rewrite_SWAP_STxxxR();
+  bool detect_rewrite_NOT_THROWIF();
 
   AsmOpConsList extract_code();
 };