diff --git a/examples/str_offset_set.php b/examples/str_offset_set.php
new file mode 100644
index 00000000..9deecb37
--- /dev/null
+++ b/examples/str_offset_set.php
@@ -0,0 +1,7 @@
+<?php
+function main()
+{
+    $hello =  "hello world";
+    $hello['0'] = array( "hello");
+    var_dump($hello);
+}
diff --git a/src/Php/Translator.php b/src/Php/Translator.php
index 581b9b2a..59059c68 100644
--- a/src/Php/Translator.php
+++ b/src/Php/Translator.php
@@ -619,6 +619,8 @@ class Translator extends \PhpAot\Core\Translator
                 return $this->parseAssignOpShiftRight($expr);
             case 'Expr_AssignOp_BitwiseAnd':
                 return $this->parseAssignOpBitwiseAnd($expr);
+            case 'Expr_AssignOp_Pow':
+                return $this->parseAssignOpPow($expr);
             case 'Expr_BinaryOp_Mul':
                 return $this->parseBinaryOpMul($expr);
             case 'Expr_BinaryOp_Concat':
@@ -676,6 +678,8 @@ class Translator extends \PhpAot\Core\Translator
                 return $this->parseClone($expr);
             case 'Expr_Throw':
                 return $this->parseThrow($expr);
+            case 'Expr_ShellExec':
+                return $this->parseShellExec($expr);
             case 'Name_FullyQualified':
                 return $expr->name;
             case 'Scalar_Int':
@@ -801,6 +805,11 @@ class Translator extends \PhpAot\Core\Translator
         return $op === '.=';
     }
 
+    private function isAssignOpPow(string $op): bool
+    {
+        return $op === '**=';
+    }
+
     /**
      * 尽可能转为数字，优先级 浮点 > 整数 > 字符串
      */
@@ -1181,10 +1190,16 @@ class Translator extends \PhpAot\Core\Translator
         $expr = $this->parseIdentifier($node->expr);
         $leftExprType = $node->var->getType();
         if ($leftExprType === self::EXPR_VARIABLE) {
+            if (!$this->hasVar($var)) {
+                $this->fatalError($node->var, 'Cannot assign to undefined variable');
+            }
             $type = $this->detectVarType($node->var);
             $rightExprStr = $this->convertExprType($expr, $type, $this->detectExprType($node->expr));
             if ($this->isAssignOpConcat($op)) {
                 return $var . '.append(' . $rightExprStr . ')';
+            } elseif ($this->isAssignOpPow($op)) {
+                $powExpr = 'php::call(php::pow, {' . $var . ', ' . $rightExprStr . '})';
+                return $var . ' = ' . $this->convertVarType($var, $powExpr);
             } else {
                 return $var . ' ' . $op . ' ' . $rightExprStr;
             }
@@ -1255,6 +1270,11 @@ class Translator extends \PhpAot\Core\Translator
         return $this->parseAssignOp($expr, '&=');
     }
 
+    private function parseAssignOpPow(mixed $expr): string
+    {
+        return $this->parseAssignOp($expr, '**=');
+    }
+
     private function fatalError(Node $node, string $msg): void
     {
         $this->climate->red("Fatal error: $msg in {$this->file}:" . $node->getStartLine());
@@ -2314,4 +2334,9 @@ class Translator extends \PhpAot\Core\Translator
 
         return $code;
     }
+
+    private function parseShellExec(mixed $expr): string
+    {
+        return 'php::call("shell_exec", {' . $this->parseInterpolatedString($expr) . '})';
+    }
 }
diff --git a/tests/aot/pow-assign-op.phpt b/tests/aot/pow-assign-op.phpt
new file mode 100644
index 00000000..ce6a0b13
--- /dev/null
+++ b/tests/aot/pow-assign-op.phpt
@@ -0,0 +1,10 @@
+--TEST--
+strlen
+--FILE--
+<?php
+$a = 2;
+$a **= 10;
+var_dump($a);
+?>
+--EXPECT--
+int(1024)
diff --git a/tests/zend/ast/ast_serialize_backtick_literal.phpt b/tests/zend/ast/ast_serialize_backtick_literal.phpt
new file mode 100644
index 00000000..b2583a0a
--- /dev/null
+++ b/tests/zend/ast/ast_serialize_backtick_literal.phpt
@@ -0,0 +1,16 @@
+--TEST--
+Serialization of backtick literal is incorrect
+--INI--
+zend.assertions=1
+--FILE--
+<?php
+
+try {
+    assert(false && `echo -n ""`);
+} catch (AssertionError $e) {
+    echo 'assert(): ', $e->getMessage(), ' failed', PHP_EOL;
+}
+
+?>
+--EXPECT--
+assert():  failed
diff --git a/tests/zend/ast/ast_serialize_floats.phpt b/tests/zend/ast/ast_serialize_floats.phpt
new file mode 100644
index 00000000..d27e8a7c
--- /dev/null
+++ b/tests/zend/ast/ast_serialize_floats.phpt
@@ -0,0 +1,26 @@
+--TEST--
+Serialization of floats are correct
+--INI--
+--FILE--
+<?php
+ini_set('zend.assertions', '1');
+try {
+    assert(!is_float(0.0));
+} catch (AssertionError $e) {
+    echo 'assert(): ', $e->getMessage(), ' failed', PHP_EOL;
+}
+try {
+    assert(!is_float(1.1));
+} catch (AssertionError $e) {
+    echo 'assert(): ', $e->getMessage(), ' failed', PHP_EOL;
+}
+try {
+    assert(!is_float(1234.5678));
+} catch (AssertionError $e) {
+    echo 'assert(): ', $e->getMessage(), ' failed', PHP_EOL;
+}
+?>
+--EXPECT--
+assert():  failed
+assert():  failed
+assert():  failed
\ No newline at end of file
diff --git a/tests/zend/ast/zend-pow-assign.phpt b/tests/zend/ast/zend-pow-assign.phpt
new file mode 100644
index 00000000..09196158
--- /dev/null
+++ b/tests/zend/ast/zend-pow-assign.phpt
@@ -0,0 +1,16 @@
+--TEST--
+ZEND_POW_ASSIGN
+--INI--
+zend.assertions=1
+--FILE--
+<?php
+
+try {
+    $a = 0;
+    assert(false && ($a **= 2));
+} catch (AssertionError $e) {
+    echo 'assert(): ', $e->getMessage(), ' failed', PHP_EOL;
+}
+?>
+--EXPECT--
+assert():  failed