diff --git a/src/codegen_x86_64.rs b/src/codegen_x86_64.rs
index 38c84de..effbc66 100644
--- a/src/codegen_x86_64.rs
+++ b/src/codegen_x86_64.rs
@@ -114,39 +114,9 @@ extern fread
 extern rewind
 extern system
 extern exit
+extern gettimeofday
 copystr equ strdup
 
-isqrt:
-    xor     rax, rax
-    mov     rcx, 1
-    mov     rbx, rdi
-    shl     rcx, 62
-.isqrt.1:
-    cmp     rcx, 0
-    je      .isqrt.5
-    cmp     rcx, rbx
-    jbe     .isqrt.2
-    shr     rcx, 2
-    jmp     .isqrt.1
-.isqrt.2:
-    cmp     rcx, 0
-    je      .isqrt.5
-    mov     rdx, rax
-    add     rdx, rcx
-    cmp     rbx, rdx
-    jb      .isqrt.3
-    sub     rbx, rdx
-    shr     rax, 1
-    add     rax, rcx
-    jmp     .isqrt.4
-.isqrt.3:
-    shr     rax, 1
-.isqrt.4:
-    shr     rcx, 2
-    jmp     .isqrt.2
-.isqrt.5:
-    ret
-
 nth:
     movzx rax, byte [rdi + rsi]
     ret
@@ -154,6 +124,54 @@ nth:
 set:
     mov [rdi + rsi], dl
     ret
+
+time:
+    push rbx
+    sub rsp, 16
+    mov rbx, rsp
+    mov rdi, rbx
+    xor esi, esi
+    call gettimeofday
+    imul rcx, qword [rbx], 1000
+    mov rax, qword [rbx+8]
+    mov esi, 1000
+    cqo
+    idiv rsi
+    add rax, rcx
+    add rsp, 16
+    pop rbx
+    ret
+
+isqrt:
+    xor rax, rax
+    mov rcx, 1
+    mov rbx, rdi
+    shl rcx, 62
+.isqrt.1:
+    cmp rcx, 0
+    je .isqrt.5
+    cmp rcx, rbx
+    jbe .isqrt.2
+    shr rcx, 2
+    jmp .isqrt.1
+.isqrt.2:
+    cmp rcx, 0
+    je .isqrt.5
+    mov rdx, rax
+    add rdx, rcx
+    cmp rbx, rdx
+    jb .isqrt.3
+    sub rbx, rdx
+    shr rax, 1
+    add rax, rcx
+    jmp .isqrt.4
+.isqrt.3:
+    shr rax, 1
+.isqrt.4:
+    shr rcx, 2
+    jmp .isqrt.2
+.isqrt.5:
+    ret
 ",
         );
         Ok(())
diff --git a/test.py b/test.py
deleted file mode 100644
index 193900d..0000000
--- a/test.py
+++ /dev/null
@@ -1,21 +0,0 @@
-import os
-import sys
-import time
-
-os.system("cargo build --release")
-
-for x in os.listdir("examples/"):
-    print(
-        "\033[93mBuilding %s...\033[0m" % x,
-        end="",
-        flush=True,
-    )
-    t = time.time()
-    if os.system("./target/release/zern examples/" + x) != 0:
-        sys.exit(1)
-    print(" %sms" % round((time.time() - t) * 1000, 2))
-
-    t = time.time()
-    if os.system("./out") != 0:
-        sys.exit(1)
-    print("\033[93mRunning %s...\033[0m %sms" % (x, round((time.time() - t) * 1000, 2)))
diff --git a/test.zr b/test.zr
new file mode 100644
index 0000000..d3f446a
--- /dev/null
+++ b/test.zr
@@ -0,0 +1,40 @@
+func run_test[x: String] : I64
+    printf("Building %s...", x)
+    let cmd: String = concat("./target/release/zern examples/", x)
+
+    let build_start_time: I64 = time()
+    if system(cmd) != 0
+        exit(1)
+    let build_end_time: I64 = time()
+
+    free(cmd)
+    printf(" %ldms\n", build_end_time - build_start_time)
+
+    let run_start_time: I64 = time()
+    if system("./out") != 0
+        exit(1)
+    let run_end_time: I64 = time()
+    
+    printf("Running %s... %ldms\n", x, run_end_time - run_start_time)
+
+func main[] : I64
+    system("cargo build --release")
+
+    // TODO
+    run_test("euler1.zr")
+    run_test("euler2.zr")
+    run_test("euler3.zr")
+    run_test("euler4.zr")
+    run_test("euler5.zr")
+    run_test("euler6.zr")
+    run_test("euler7.zr")
+    run_test("euler8.zr")
+    run_test("euler9.zr")
+    run_test("euler10.zr")
+    run_test("euler12.zr")
+    run_test("euler13.zr")
+    run_test("euler14.zr")
+    run_test("euler15.zr")
+    run_test("fib.zr")
+    run_test("hello.zr")
+    run_test("strings.zr")
\ No newline at end of file