Add missing chkstk.S files from r242539

llvm-svn: 242540

Author: rnk

compiler-rt/lib/builtins/i386/chkstk.S

@@ -0,0 +1,34 @@
+// 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
+
+#ifdef __i386__
+
+.text
+.balign 4
+DEFINE_COMPILERRT_FUNCTION(__chkstk_ms)
+        push   %ecx
+        push   %eax
+        cmp    $0x1000,%eax
+        lea    12(%esp),%ecx
+        jb     1f
+2:
+        sub    $0x1000,%ecx
+        orl    $0,(%ecx)
+        sub    $0x1000,%eax
+        cmp    $0x1000,%eax
+        ja     2b
+1:
+        sub    %eax,%ecx
+        orl    $0,(%ecx)
+        pop    %eax
+        pop    %ecx
+        ret
+END_COMPILERRT_FUNCTION(__chkstk_ms)
+
+#endif // __i386__

compiler-rt/lib/builtins/x86_64/chkstk.S

@@ -0,0 +1,39 @@
+// 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
+
+// Notes from r227519
+// MSVC x64s __chkstk and cygmings ___chkstk_ms do not adjust %rsp
+// themselves. It also does not clobber %rax so we can reuse it when
+// adjusting %rsp.
+
+#ifdef __x86_64__
+
+.text
+.balign 4
+DEFINE_COMPILERRT_FUNCTION(___chkstk_ms)
+        push   %rcx
+        push   %rax
+        cmp    $0x1000,%rax
+        lea    24(%rsp),%rcx
+        jb     1f
+2:
+        sub    $0x1000,%rcx
+        orl    $0,(%rcx)
+        sub    $0x1000,%rax
+        cmp    $0x1000,%rax
+        ja     2b
+1:
+        sub    %rax,%rcx
+        orl    $0,(%rcx)
+        pop    %rax
+        pop    %rcx
+        ret
+END_COMPILERRT_FUNCTION(___chkstk_ms)
+
+#endif // __x86_64__