optimize the create of arrays - optimized the rest and array_from opcodes

Author: Fabrice Bellard

quickjs.c

@@ -8914,6 +8914,57 @@ static JSValue js_allocate_fast_array(JSContext *ctx, int64_t len)
     return arr;
 }
 
+static JSValue js_create_array(JSContext *ctx, int len, JSValueConst *tab)
+{
+    JSValue obj;
+    JSObject *p;
+    int i;
+
+    obj = JS_NewArray(ctx);
+    if (JS_IsException(obj))
+        return JS_EXCEPTION;
+    if (len > 0) {
+        p = JS_VALUE_GET_OBJ(obj);
+        if (expand_fast_array(ctx, p, len) < 0) {
+            JS_FreeValue(ctx, obj);
+            return JS_EXCEPTION;
+        }
+        p->u.array.count = len;
+        for(i = 0; i < len; i++) 
+            p->u.array.u.values[i] = JS_DupValue(ctx, tab[i]);
+        /* update the 'length' field */
+        set_value(ctx, &p->prop[0].u.value, JS_NewInt32(ctx, len));
+    }
+    return obj;
+}
+
+static JSValue js_create_array_free(JSContext *ctx, int len, JSValue *tab)
+{
+    JSValue obj;
+    JSObject *p;
+    int i;
+
+    obj = JS_NewArray(ctx);
+    if (JS_IsException(obj))
+        goto fail;
+    if (len > 0) {
+        p = JS_VALUE_GET_OBJ(obj);
+        if (expand_fast_array(ctx, p, len) < 0) {
+            JS_FreeValue(ctx, obj);
+        fail:
+            for(i = 0; i < len; i++)
+                JS_FreeValue(ctx, tab[i]);
+            return JS_EXCEPTION;
+        }
+        p->u.array.count = len;
+        for(i = 0; i < len; i++) 
+            p->u.array.u.values[i] = tab[i];
+        /* update the 'length' field */
+        set_value(ctx, &p->prop[0].u.value, JS_NewInt32(ctx, len));
+    }
+    return obj;
+}
+
 static void js_free_desc(JSContext *ctx, JSPropertyDescriptor *desc)
 {
     JS_FreeValue(ctx, desc->getter);
@@ -15620,26 +15671,6 @@ static JSValue js_build_mapped_arguments(JSContext *ctx, int argc,
     return JS_EXCEPTION;
 }
 
-static JSValue js_build_rest(JSContext *ctx, int first, int argc, JSValueConst *argv)
-{
-    JSValue val;
-    int i, ret;
-
-    val = JS_NewArray(ctx);
-    if (JS_IsException(val))
-        return val;
-    for (i = first; i < argc; i++) {
-        ret = JS_DefinePropertyValueUint32(ctx, val, i - first,
-                                           JS_DupValue(ctx, argv[i]),
-                                           JS_PROP_C_W_E);
-        if (ret < 0) {
-            JS_FreeValue(ctx, val);
-            return JS_EXCEPTION;
-        }
-    }
-    return val;
-}
-
 static JSValue build_for_in_iterator(JSContext *ctx, JSValue obj)
 {
     JSObject *p, *p1;
@@ -17122,7 +17153,8 @@ static JSValue JS_CallInternal(JSContext *caller_ctx, JSValueConst func_obj,
             {
                 int first = get_u16(pc);
                 pc += 2;
-                *sp++ = js_build_rest(ctx, first, argc, (JSValueConst *)argv);
+                first = min_int(first, argc);
+                *sp++ = js_create_array(ctx, argc - first, (JSValueConst *)(argv + first));
                 if (unlikely(JS_IsException(sp[-1])))
                     goto exception;
             }
@@ -17345,27 +17377,13 @@ static JSValue JS_CallInternal(JSContext *caller_ctx, JSValueConst func_obj,
             }
             BREAK;
         CASE(OP_array_from):
-            {
-                int i, ret;
-
-                call_argc = get_u16(pc);
-                pc += 2;
-                ret_val = JS_NewArray(ctx);
-                if (unlikely(JS_IsException(ret_val)))
-                    goto exception;
-                call_argv = sp - call_argc;
-                for(i = 0; i < call_argc; i++) {
-                    ret = JS_DefinePropertyValue(ctx, ret_val, __JS_AtomFromUInt32(i), call_argv[i],
-                                                 JS_PROP_C_W_E | JS_PROP_THROW);
-                    call_argv[i] = JS_UNDEFINED;
-                    if (ret < 0) {
-                        JS_FreeValue(ctx, ret_val);
-                        goto exception;
-                    }
-                }
-                sp -= call_argc;
-                *sp++ = ret_val;
-            }
+            call_argc = get_u16(pc);
+            pc += 2;
+            ret_val = js_create_array_free(ctx, call_argc, sp - call_argc);
+            sp -= call_argc;
+            if (unlikely(JS_IsException(ret_val)))
+                goto exception;
+            *sp++ = ret_val;
             BREAK;
 
         CASE(OP_apply):
@@ -42104,23 +42122,6 @@ static void js_array_iterator_mark(JSRuntime *rt, JSValueConst val,
     }
 }
 
-static JSValue js_create_array(JSContext *ctx, int len, JSValueConst *tab)
-{
-    JSValue obj;
-    int i;
-
-    obj = JS_NewArray(ctx);
-    if (JS_IsException(obj))
-        return JS_EXCEPTION;
-    for(i = 0; i < len; i++) {
-        if (JS_CreateDataPropertyUint32(ctx, obj, i, JS_DupValue(ctx, tab[i]), 0) < 0) {
-            JS_FreeValue(ctx, obj);
-            return JS_EXCEPTION;
-        }
-    }
-    return obj;
-}
-
 static JSValue js_create_array_iterator(JSContext *ctx, JSValueConst this_val,
                                         int argc, JSValueConst *argv, int magic)
 {