diff --git a/runtime/internal/clite/debug/debug_baremental.go b/runtime/internal/clite/debug/debug_baremetal.go
similarity index 100%
rename from runtime/internal/clite/debug/debug_baremental.go
rename to runtime/internal/clite/debug/debug_baremetal.go
diff --git a/runtime/internal/clite/stdio_baremental.go b/runtime/internal/clite/stdio_baremetal.go
similarity index 100%
rename from runtime/internal/clite/stdio_baremental.go
rename to runtime/internal/clite/stdio_baremetal.go
diff --git a/runtime/internal/lib/internal/syscall/unix/fcntl_unix.go b/runtime/internal/lib/internal/syscall/unix/fcntl_unix.go
index 93c768d9..a6865c3f 100644
--- a/runtime/internal/lib/internal/syscall/unix/fcntl_unix.go
+++ b/runtime/internal/lib/internal/syscall/unix/fcntl_unix.go
@@ -1,3 +1,5 @@
+//go:build !baremetal
+
 package unix
 
 import (
diff --git a/runtime/internal/lib/runtime/maxprocs_baremental.go b/runtime/internal/lib/runtime/maxprocs_baremetal.go
similarity index 100%
rename from runtime/internal/lib/runtime/maxprocs_baremental.go
rename to runtime/internal/lib/runtime/maxprocs_baremetal.go
diff --git a/runtime/internal/runtime/rethrow_baremental.go b/runtime/internal/runtime/z_baremetal.go
similarity index 74%
rename from runtime/internal/runtime/rethrow_baremental.go
rename to runtime/internal/runtime/z_baremetal.go
index 98433909..b51285e0 100644
--- a/runtime/internal/runtime/rethrow_baremental.go
+++ b/runtime/internal/runtime/z_baremetal.go
@@ -4,6 +4,12 @@ package runtime
 
 import c "github.com/goplus/llgo/runtime/internal/clite"
 
+var (
+	printFormatPrefixInt  = c.Str("%ld")
+	printFormatPrefixUInt = c.Str("%lu")
+	printFormatPrefixHex  = c.Str("%lx")
+)
+
 // Rethrow rethrows a panic.
 func Rethrow(link *Defer) {
 	// in baremetal environment, we cannot get debug data from pthread_getspecific
diff --git a/runtime/internal/runtime/rethrow_default.go b/runtime/internal/runtime/z_default.go
similarity index 84%
rename from runtime/internal/runtime/rethrow_default.go
rename to runtime/internal/runtime/z_default.go
index a481d058..0276d2dd 100644
--- a/runtime/internal/runtime/rethrow_default.go
+++ b/runtime/internal/runtime/z_default.go
@@ -8,6 +8,12 @@ import (
 	"github.com/goplus/llgo/runtime/internal/clite/pthread"
 )
 
+var (
+	printFormatPrefixInt  = c.Str("%lld")
+	printFormatPrefixUInt = c.Str("%llu")
+	printFormatPrefixHex  = c.Str("%llx")
+)
+
 // Rethrow rethrows a panic.
 func Rethrow(link *Defer) {
 	if ptr := excepKey.Get(); ptr != nil {
diff --git a/runtime/internal/runtime/z_print.go b/runtime/internal/runtime/z_print.go
index 02b3c9b3..11e04640 100644
--- a/runtime/internal/runtime/z_print.go
+++ b/runtime/internal/runtime/z_print.go
@@ -70,15 +70,15 @@ func PrintComplex(v complex128) {
 }
 
 func PrintUint(v uint64) {
-	c.Fprintf(c.Stderr, c.Str("%llu"), v)
+	c.Fprintf(c.Stderr, printFormatPrefixUInt, v)
 }
 
 func PrintInt(v int64) {
-	c.Fprintf(c.Stderr, c.Str("%lld"), v)
+	c.Fprintf(c.Stderr, printFormatPrefixInt, v)
 }
 
 func PrintHex(v uint64) {
-	c.Fprintf(c.Stderr, c.Str("%llx"), v)
+	c.Fprintf(c.Stderr, printFormatPrefixHex, v)
 }
 
 func PrintPointer(p unsafe.Pointer) {