diff --git a/alloca86-bt.S b/alloca86-bt.S
new file mode 100644
index 0000000..50a671e
--- /dev/null
+++ b/alloca86-bt.S
@@ -0,0 +1,42 @@
+/* ---------------------------------------------- */
+/* alloca86b.S */
+
+.globl __bound___alloca
+
+__bound___alloca:
+    pop     %edx
+    pop     %eax
+    mov     %eax, %ecx
+    add     $3,%eax
+    and     $-4,%eax
+    jz      p6
+
+p4:
+    cmp     $4096,%eax
+    jle     p5
+    sub     $4096,%esp
+    sub     $4096,%eax
+    test    %eax,(%esp)
+    jmp p4
+
+p5:
+    sub     %eax,%esp
+    mov     %esp,%eax
+
+    push    %edx
+    push    %eax
+
+    push    %ecx
+    push    %eax
+    call   __bound_new_region
+    add    $8, %esp
+
+    pop     %eax
+    pop     %edx
+
+p6:
+    push    %edx
+    push    %edx
+    ret
+
+/* ---------------------------------------------- */
diff --git a/alloca86.S b/alloca86.S
new file mode 100644
index 0000000..c8f0c25
--- /dev/null
+++ b/alloca86.S
@@ -0,0 +1,27 @@
+/* ---------------------------------------------- */
+/* alloca86.S */
+
+.globl _alloca
+
+_alloca:
+    pop     %edx
+    pop     %eax
+    add     $3,%eax
+    and     $-4,%eax
+    jz      p3
+p1:
+    cmp     $4096,%eax
+    jle     p2
+    sub     $4096,%esp
+    sub     $4096,%eax
+    test    %eax,(%esp)
+    jmp p1
+p2:
+    sub     %eax,%esp
+    mov     %esp,%eax
+p3:
+    push    %edx
+    push    %edx
+    ret
+
+/* ---------------------------------------------- */