diff --git a/rust/src/bin/float.rs b/rust/src/bin/float.rs
new file mode 100644
index 0000000..578ba8e
--- /dev/null
+++ b/rust/src/bin/float.rs
@@ -0,0 +1,29 @@
+#![no_std]
+#![no_main]
+#![feature(asm)]
+
+#[macro_use]
+extern crate rcore_user;
+
+use rcore_user::syscall::*;
+
+
+// IMPORTANT: Must define main() like this
+#[no_mangle]
+pub fn main() {
+    println!("Going to test floating point arithmetics");
+    println!("And see if it works with context switch");
+    sys_vfork();
+    sys_vfork();
+    let pid = sys_getpid();
+    for i in 0..10 {
+        let a = pid as f32;
+        let b = 1.0_f32;
+        let c_1 = a + b;
+        sys_sleep(1);
+        let c_2 = (pid + 1) as f32;
+        if c_1 - c_2 < 1e-4 && c_1 - c_2 > -1e-4 {
+            println!("pid {} time {}: working", pid, i);
+        }
+    }
+}
diff --git a/rust/src/bin/iperf.rs b/rust/src/bin/iperf.rs
index f210885..75ff989 100644
--- a/rust/src/bin/iperf.rs
+++ b/rust/src/bin/iperf.rs
@@ -244,9 +244,6 @@ pub fn main() {
                     }
                 }
             }
-            if !socket.is_open() {
-
-            }
         }
 
         {
diff --git a/rust/targets/x86_64-rcore.json b/rust/targets/x86_64-rcore.json
index 6510efa..3ba7450 100644
--- a/rust/targets/x86_64-rcore.json
+++ b/rust/targets/x86_64-rcore.json
@@ -11,5 +11,5 @@
   "linker-flavor": "ld.lld",
   "panic-strategy": "abort",
   "disable-redzone": true,
-  "features": "-mmx,-sse,+soft-float"
+  "features": ""
 }