diff --git a/userland/arch/x86_64/inline_asm/sqrt_x87.c b/userland/arch/x86_64/inline_asm/sqrt_x87.c
new file mode 100644
index 0000000..b37aa06
--- /dev/null
+++ b/userland/arch/x86_64/inline_asm/sqrt_x87.c
@@ -0,0 +1,15 @@
+/* https://github.com/cirosantilli/linux-kernel-module-cheat#gcc-inline-assembly */
+
+#include <assert.h>
+
+int main(void) {
+    double io = 4.0;
+    __asm__ (
+        "fsqrt"
+        : "+t" (io)
+        :
+        :
+    );
+    assert(io == 2.0);
+    return 0;
+}