Normalize wasm types (#1378)

Normalize wasm types, for the two wasm types, if their parameter types
and result types are the same, we only save one copy, so as to reduce
the footprint and simplify the type comparison in opcode CALL_INDIRECT.

And fix issue in interpreter globals_instantiate, and remove used codes.

core/iwasm/aot/aot_runtime.c

@@ -2205,28 +2205,6 @@ aot_enlarge_memory(AOTModuleInstance *module_inst, uint32 inc_page_count)
 }
 #endif /* end of OS_ENABLE_HW_BOUND_CHECK */
 
-bool
-aot_is_wasm_type_equal(AOTModuleInstance *module_inst, uint32 type1_idx,
-                       uint32 type2_idx)
-{
-    WASMType *type1, *type2;
-    AOTModule *module = (AOTModule *)module_inst->aot_module.ptr;
-
-    if (type1_idx >= module->func_type_count
-        || type2_idx >= module->func_type_count) {
-        aot_set_exception(module_inst, "type index out of bounds");
-        return false;
-    }
-
-    if (type1_idx == type2_idx)
-        return true;
-
-    type1 = module->func_types[type1_idx];
-    type2 = module->func_types[type2_idx];
-
-    return wasm_type_equal(type1, type2);
-}
-
 bool
 aot_invoke_native(WASMExecEnv *exec_env, uint32 func_idx, uint32 argc,
                   uint32 *argv)

core/iwasm/aot/aot_runtime.h

@@ -633,9 +633,6 @@ aot_enlarge_memory(AOTModuleInstance *module_inst, uint32 inc_page_count);
  *
  * @return true if equal, false otherwise
  */
-bool
-aot_is_wasm_type_equal(AOTModuleInstance *module_inst, uint32 type1_idx,
-                       uint32 type2_idx);
 
 /**
  * Invoke native function from aot code

core/iwasm/interpreter/wasm.h

@@ -122,6 +122,7 @@ typedef struct WASMType {
     uint16 result_count;
     uint16 param_cell_num;
     uint16 ret_cell_num;
+    uint16 ref_count;
     /* types of params and results */
     uint8 types[1];
 } WASMType;
@@ -612,6 +613,9 @@ wasm_value_type_cell_num_outside(uint8 value_type)
 inline static bool
 wasm_type_equal(const WASMType *type1, const WASMType *type2)
 {
+    if (type1 == type2) {
+        return true;
+    }
     return (type1->param_count == type2->param_count
             && type1->result_count == type2->result_count
             && memcmp(type1->types, type2->types,

core/iwasm/interpreter/wasm_interp_classic.c

@@ -1391,7 +1391,7 @@ wasm_interp_call_func_bytecode(WASMModuleInstance *module,
                 tbl_inst = wasm_get_table_inst(module, tbl_idx);
 
                 val = POP_I32();
-                if (val < 0 || val >= (int32)tbl_inst->cur_size) {
+                if ((uint32)val >= tbl_inst->cur_size) {
                     wasm_set_exception(module, "undefined element");
                     goto got_exception;
                 }
@@ -1419,10 +1419,12 @@ wasm_interp_call_func_bytecode(WASMModuleInstance *module,
                     cur_func_type = cur_func->u.func_import->func_type;
                 else
                     cur_func_type = cur_func->u.func->func_type;
-                if (!wasm_type_equal(cur_type, cur_func_type)) {
+
+                if (cur_type != cur_func_type) {
                     wasm_set_exception(module, "indirect call type mismatch");
                     goto got_exception;
                 }
+
 #if WASM_ENABLE_TAIL_CALL != 0
                 if (opcode == WASM_OP_RETURN_CALL_INDIRECT)
                     goto call_func_from_return_call;

core/iwasm/interpreter/wasm_interp_fast.c

@@ -1316,7 +1316,7 @@ wasm_interp_call_func_bytecode(WASMModuleInstance *module,
                 val = GET_OPERAND(uint32, I32, 0);
                 frame_ip += 2;
 
-                if (val < 0 || val >= (int32)tbl_inst->cur_size) {
+                if ((uint32)val >= tbl_inst->cur_size) {
                     wasm_set_exception(module, "undefined element");
                     goto got_exception;
                 }
@@ -1344,10 +1344,12 @@ wasm_interp_call_func_bytecode(WASMModuleInstance *module,
                     cur_func_type = cur_func->u.func_import->func_type;
                 else
                     cur_func_type = cur_func->u.func->func_type;
-                if (!wasm_type_equal(cur_type, cur_func_type)) {
+
+                if (cur_type != cur_func_type) {
                     wasm_set_exception(module, "indirect call type mismatch");
                     goto got_exception;
                 }
+
 #if WASM_ENABLE_TAIL_CALL != 0
                 if (opcode == WASM_OP_RETURN_CALL_INDIRECT)
                     goto call_func_from_return_call;

core/iwasm/interpreter/wasm_loader.c

@@ -415,6 +415,19 @@ const_str_list_insert(const uint8 *str, uint32 len, WASMModule *module,
     return node->str;
 }
 
+static void
+destroy_wasm_type(WASMType *type)
+{
+    if (type->ref_count > 1) {
+        /* The type is referenced by other types
+           of current wasm module */
+        type->ref_count--;
+        return;
+    }
+
+    wasm_runtime_free(type);
+}
+
 static bool
 load_init_expr(const uint8 **p_buf, const uint8 *buf_end,
                InitializerExpression *init_expr, uint8 type, char *error_buf,
@@ -582,6 +595,7 @@ load_type_section(const uint8 *buf, const uint8 *buf_end, WASMModule *module,
             }
 
             /* Resolve param types and result types */
+            type->ref_count = 1;
             type->param_count = (uint16)param_count;
             type->result_count = (uint16)result_count;
             for (j = 0; j < param_count; j++) {
@@ -611,6 +625,21 @@ load_type_section(const uint8 *buf, const uint8 *buf_end, WASMModule *module,
             }
             type->param_cell_num = (uint16)param_cell_num;
             type->ret_cell_num = (uint16)ret_cell_num;
+
+            /* If there is already a same type created, use it instead */
+            for (j = 0; j < i; j++) {
+                if (wasm_type_equal(type, module->types[j])) {
+                    if (module->types[j]->ref_count == UINT16_MAX) {
+                        set_error_buf(error_buf, error_buf_size,
+                                      "wasm type's ref count too large");
+                        return false;
+                    }
+                    destroy_wasm_type(type);
+                    module->types[i] = module->types[j];
+                    module->types[j]->ref_count++;
+                    break;
+                }
+            }
         }
     }
 
@@ -3729,7 +3758,7 @@ wasm_loader_unload(WASMModule *module)
     if (module->types) {
         for (i = 0; i < module->type_count; i++) {
             if (module->types[i])
-                wasm_runtime_free(module->types[i]);
+                destroy_wasm_type(module->types[i]);
         }
         wasm_runtime_free(module->types);
     }

core/iwasm/interpreter/wasm_mini_loader.c

@@ -248,6 +248,19 @@ const_str_list_insert(const uint8 *str, uint32 len, WASMModule *module,
     return node->str;
 }
 
+static void
+destroy_wasm_type(WASMType *type)
+{
+    if (type->ref_count > 1) {
+        /* The type is referenced by other types
+           of current wasm module */
+        type->ref_count--;
+        return;
+    }
+
+    wasm_runtime_free(type);
+}
+
 static bool
 load_init_expr(const uint8 **p_buf, const uint8 *buf_end,
                InitializerExpression *init_expr, uint8 type, char *error_buf,
@@ -372,6 +385,7 @@ load_type_section(const uint8 *buf, const uint8 *buf_end, WASMModule *module,
             }
 
             /* Resolve param types and result types */
+            type->ref_count = 1;
             type->param_count = (uint16)param_count;
             type->result_count = (uint16)result_count;
             for (j = 0; j < param_count; j++) {
@@ -394,6 +408,17 @@ load_type_section(const uint8 *buf, const uint8 *buf_end, WASMModule *module,
                       && ret_cell_num <= UINT16_MAX);
             type->param_cell_num = (uint16)param_cell_num;
             type->ret_cell_num = (uint16)ret_cell_num;
+
+            /* If there is already a same type created, use it instead */
+            for (j = 0; j < i; ++j) {
+                if (wasm_type_equal(type, j)) {
+                    bh_assert(module->types[j]->ref_count != UINT16_MAX);
+                    destroy_wasm_type(type);
+                    module->types[i] = module->types[j];
+                    module->types[j]->ref_count++;
+                    break;
+                }
+            }
         }
     }
 
@@ -2400,7 +2425,7 @@ wasm_loader_unload(WASMModule *module)
     if (module->types) {
         for (i = 0; i < module->type_count; i++) {
             if (module->types[i])
-                wasm_runtime_free(module->types[i]);
+                destroy_wasm_type(module->types[i]);
         }
         wasm_runtime_free(module->types);
     }

core/iwasm/interpreter/wasm_runtime.c

@@ -787,13 +787,13 @@ globals_instantiate(const WASMModule *module, WASMModuleInstance *module_inst,
             if (!(global->import_module_inst = get_sub_module_inst(
                       module_inst, global_import->import_module))) {
                 set_error_buf(error_buf, error_buf_size, "unknown global");
-                return NULL;
+                goto fail;
             }
 
             if (!(global->import_global_inst = wasm_lookup_global(
                       global->import_module_inst, global_import->field_name))) {
                 set_error_buf(error_buf, error_buf_size, "unknown global");
-                return NULL;
+                goto fail;
             }
 
             /* The linked global instance has been initialized, we
@@ -829,7 +829,7 @@ globals_instantiate(const WASMModule *module, WASMModuleInstance *module_inst,
         if (init_expr->init_expr_type == INIT_EXPR_TYPE_GET_GLOBAL) {
             if (!check_global_init_expr(module, init_expr->u.global_index,
                                         error_buf, error_buf_size)) {
-                return NULL;
+                goto fail;
             }
 
             bh_memcpy_s(
@@ -853,6 +853,9 @@ globals_instantiate(const WASMModule *module, WASMModuleInstance *module_inst,
     *p_global_data_size = global_data_offset;
     (void)module_inst;
     return globals;
+fail:
+    wasm_runtime_free(globals);
+    return NULL;
 }
 
 /**
@@ -2663,7 +2666,7 @@ call_indirect(WASMExecEnv *exec_env, uint32 tbl_idx, uint32 elem_idx,
         else
             cur_func_type = func_inst->u.func->func_type;
 
-        if (!wasm_type_equal(cur_type, cur_func_type)) {
+        if (cur_type != cur_func_type) {
             wasm_set_exception(module_inst, "indirect call type mismatch");
             goto got_exception;
         }