diff --git a/README.md b/README.md
index 9628e7979..05ecaf0b1 100644
--- a/README.md
+++ b/README.md
@@ -171,7 +171,6 @@ Common Go syntax is already supported. Except for the following, which needs to
 
 * map (Very limited support)
 * chan (Not supported yet)
-* generics (Not supported yet)
 
 Here are some examples related to Go syntax:
 
@@ -212,7 +211,7 @@ Here are the Go packages that can be imported correctly:
 * [strconv](https://pkg.go.dev/strconv)
 * [syscall](https://pkg.go.dev/syscall) (partially)
 * [sync](https://pkg.go.dev/sync) (partially)
-* [sync/atomic](https://pkg.go.dev/sync/atomic) (partially)
+* [sync/atomic](https://pkg.go.dev/sync/atomic)
 
 
 ## Dependencies
diff --git a/c/bitcast/_cast/cast.c b/c/bitcast/_cast/cast.c
new file mode 100644
index 000000000..bcc90d648
--- /dev/null
+++ b/c/bitcast/_cast/cast.c
@@ -0,0 +1,17 @@
+typedef union {
+    double d;
+    float  f;
+    long   v;
+} castUnion;
+
+double llgoToFloat64(long v) {
+    castUnion k;
+    k.v = v;
+    return k.d;
+}
+
+float llgoToFloat32(long v) {
+    castUnion k;
+    k.v = v;
+    return k.f;
+}
diff --git a/c/bitcast/bitcast.go b/c/bitcast/bitcast.go
new file mode 100644
index 000000000..f6d123518
--- /dev/null
+++ b/c/bitcast/bitcast.go
@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) 2024 The GoPlus Authors (goplus.org). All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package bitcast
+
+import _ "unsafe"
+
+const (
+	LLGoFiles   = "_cast/cast.c"
+	LLGoPackage = "link"
+)
+
+//go:linkname ToFloat64 C.llgoToFloat64
+func ToFloat64(v uintptr) float64
+
+//go:linkname ToFloat32 C.llgoToFloat32
+func ToFloat32(v uintptr) float32
diff --git a/c/bitcast/llgo_autogen.lla b/c/bitcast/llgo_autogen.lla
new file mode 100644
index 000000000..e495204ad
Binary files /dev/null and b/c/bitcast/llgo_autogen.lla differ
diff --git a/internal/lib/sync/atomic/atomic.go b/internal/lib/sync/atomic/atomic.go
index 11bef422a..8d7bc8a38 100644
--- a/internal/lib/sync/atomic/atomic.go
+++ b/internal/lib/sync/atomic/atomic.go
@@ -16,7 +16,6 @@
 
 package atomic
 
-// llgo:skipall
 import (
 	"unsafe"
 )
diff --git a/internal/runtime/z_rt.go b/internal/runtime/z_rt.go
index 9d9eea339..6653ff3d0 100644
--- a/internal/runtime/z_rt.go
+++ b/internal/runtime/z_rt.go
@@ -20,6 +20,7 @@ import (
 	"unsafe"
 
 	"github.com/goplus/llgo/c"
+	"github.com/goplus/llgo/c/bitcast"
 	"github.com/goplus/llgo/c/pthread"
 	"github.com/goplus/llgo/internal/abi"
 )
@@ -58,7 +59,7 @@ func Panic(v any) {
 func Rethrow(link *Defer) {
 	if ptr := excepKey.Get(); ptr != nil {
 		if link == nil {
-			TracePanic(*(*Eface)(ptr))
+			TracePanic(*(*any)(ptr))
 			c.Free(ptr)
 			c.Exit(2)
 		} else {
@@ -77,14 +78,57 @@ func init() {
 
 // -----------------------------------------------------------------------------
 
+func unpackEface(i any) *eface {
+	return (*eface)(unsafe.Pointer(&i))
+}
+
 // TracePanic prints panic message.
-func TracePanic(v Eface) {
-	kind := v._type.Kind()
-	switch {
-	case kind == abi.String:
-		stringTracef(c.Stderr, c.Str("panic: %s\n"), *(*String)(v.data))
+func TracePanic(v any) {
+	print("panic: ")
+	switch e := v.(type) {
+	case nil:
+		println("nil")
+		return
+	case (interface{ Error() string }):
+		println(e.Error())
+		return
+	case (interface{ String() string }):
+		println(e.String())
+		return
+	}
+	e := unpackEface(v)
+	switch e.Kind() {
+	case abi.Int, abi.Int8, abi.Int16, abi.Int32, abi.Int64:
+		if isDirectIface(e._type) {
+			println(int64(uintptr(e.data)))
+		} else {
+			println(*(*int64)(e.data))
+		}
+	case abi.Uint, abi.Uint8, abi.Uint16, abi.Uint32, abi.Uint64, abi.Uintptr:
+		if isDirectIface(e._type) {
+			println(uint64(uintptr(e.data)))
+		} else {
+			println(*(*uint64)(e.data))
+		}
+	case abi.Float32:
+		if isDirectIface(e._type) {
+			println(bitcast.ToFloat32((uintptr(e.data))))
+		} else {
+			println(*(*float32)(e.data))
+		}
+	case abi.Float64:
+		if isDirectIface(e._type) {
+			println(bitcast.ToFloat64(uintptr(e.data)))
+		} else {
+			println(*(*float64)(e.data))
+		}
+	case abi.String:
+		println(*(*string)(e.data))
+	default:
+		// TODO kind to e._type.Str_
+		print("(", e.Kind(), ") ")
+		println(e.data)
 	}
-	// TODO(xsw): other message type
 }
 
 func stringTracef(fp c.FilePtr, format *c.Char, s String) {