diff --git a/lisp/llvm-lib/llvm-act-on-file/act-on-c-file.el b/lisp/llvm-lib/llvm-act-on-file/act-on-c-file.el
index 6d482e7..3cf108b 100644
--- a/lisp/llvm-lib/llvm-act-on-file/act-on-c-file.el
+++ b/lisp/llvm-lib/llvm-act-on-file/act-on-c-file.el
@@ -27,6 +27,7 @@
 (require 'llvm-shared)
 (require 'action-map-lib)
 (require 'anaphora)
+(require 'make-tmp-output-file)
 
 (defvar ll/c-file-action-map
   '((debug        :key ?d    :major-mode llvm-mode :buffer-string "debug"              :description "[d]ebug pass"             :compiler-action assemble)
@@ -151,7 +152,7 @@
 
 (defun ll/act-on-c-file (file)
   (let* ((action (aml/read-action-map ll/c-file-action-map))
-         (output (make-temp-file (concat (file-name-sans-extension file) "-") nil ".ll")))
+         (output (ll/make-tmp-file file ".ll")))
     (if (eq action 'diff)
         (ll/diff-c-on-two-compilations file action)
       (let ((comm (ll/build-clang-command (lls/un-trampify file) action output)))
diff --git a/lisp/llvm-lib/llvm-act-on-file/act-on-ll-file.el b/lisp/llvm-lib/llvm-act-on-file/act-on-ll-file.el
index 8cb2acf..87ba1d2 100644
--- a/lisp/llvm-lib/llvm-act-on-file/act-on-ll-file.el
+++ b/lisp/llvm-lib/llvm-act-on-file/act-on-ll-file.el
@@ -25,6 +25,7 @@
 ;;; Code:
 (require 'llvm-shared)
 (require 'action-map-lib)
+(require 'make-tmp-output-file)
 
 (defvar ll/ll-file-action-map
   '((assembly     :key ?a  :major-mode asm-mode  :buffer-string "assembly"  :description "[a]ssembly")
@@ -45,9 +46,12 @@
          ;; I just recently noticed that the default directory is changing, but
          ;; I don't know what changed. Should investigate later.
          (default-directory (file-name-directory file))
-         (output (make-temp-file
-                  (concat (file-name-sans-extension file) "-")
-                  nil ".mir")))
+         (output (ll/make-tmp-file
+                  file
+                  (cond
+                   ((eq action 'assembly)
+                    ".S")
+                   (t ".mir")))))
     (aprog1
         (compilation-start
          (ll/build-llc-command file action output pass)
diff --git a/lisp/llvm-lib/llvm-act-on-file/make-tmp-output-file.el b/lisp/llvm-lib/llvm-act-on-file/make-tmp-output-file.el
new file mode 100644
index 0000000..15ccc21
--- /dev/null
+++ b/lisp/llvm-lib/llvm-act-on-file/make-tmp-output-file.el
@@ -0,0 +1,38 @@
+;;; make-tmp-output-file.el ---  -*- lexical-binding: t -*-
+
+;; Copyright (C) 2024 Benson Chu
+
+;; Author: Benson Chu <bensonchu457@gmail.com>
+;; Created: [2024-10-25 19:36]
+
+;; This file is not part of GNU Emacs
+
+;; This program is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; This program is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;;; Code:
+
+(defun ll/make-tmp-file (file ext)
+  (let (fname temporary-file-directory)
+    (if (string-match-p (rx "/.tmp") file)
+        (setq fname (file-name-sans-extension file)
+              temporary-file-directory (file-name-directory file))
+      (setq fname (file-name-nondirectory (file-name-sans-extension file))
+            temporary-file-directory (expand-file-name ".tmp" default-directory)))
+    (make-temp-file (concat fname "-")
+                    nil ext)))
+
+(provide 'make-tmp-output-file)
+;;; make-tmp-output-file.el ends here