--- /dev/null
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+
+#include "../assembly.h"
+
+// __chkstk routine
+// This routine is windows specific.
+// http://msdn.microsoft.com/en-us/library/ms648426.aspx
+
+// This clobbers the register r12, and the condition codes, and uses r5 and r6
+// as temporaries by backing them up and restoring them afterwards.
+// Does not modify any memory or the stack pointer.
+
+// movw r4, #256 // Number of bytes of stack, in units of 4 byte
+// bl __chkstk
+// sub.w sp, sp, r4
+
+#define PAGE_SIZE 4096
+
+ .p2align 2
+DEFINE_COMPILERRT_FUNCTION(__chkstk)
+ lsl r4, r4, #2
+ mov r12, sp
+ push {r5, r6}
+ mov r5, r4
+1:
+ sub r12, r12, #PAGE_SIZE
+ subs r5, r5, #PAGE_SIZE
+ ldr r6, [r12]
+ bgt 1b
+
+ pop {r5, r6}
+ bx lr
+END_COMPILERRT_FUNCTION(__chkstk)