3 files changed, 114 insertions, 3 deletions

diff --git a/mps/code/mps.c b/mps/code/mps.c
index ae14469bda9..900f12877b2 100644
--- a/mps/code/mps.c
+++ b/mps/code/mps.c
@@ -99,7 +99,7 @@
 #include "protsgix.c"
 #include "prmcan.c"
 #include "span.c"
-#include "ssan.c"
+#include "ssixi6.c"
 
 #else
 
diff --git a/mps/code/mps.xcodeproj/project.pbxproj b/mps/code/mps.xcodeproj/project.pbxproj
index 8c18f9c8edb..c5780878651 100644
--- a/mps/code/mps.xcodeproj/project.pbxproj
+++ b/mps/code/mps.xcodeproj/project.pbxproj
@@ -104,6 +104,7 @@
 /* End PBXCopyFilesBuildPhase section */
 
 /* Begin PBXFileReference section */
+                3104AFA5156D27E7000A585A /* ssixi6.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = ssixi6.c; sourceTree = "<group>"; };
                 3124CAB8156BE3EC00753214 /* awlut */ = {isa = PBXFileReference; explicitFileType = "compiled.mach-o.executable"; includeInIndex = 0; path = awlut; sourceTree = BUILT_PRODUCTS_DIR; };
                 3124CAC2156BE40100753214 /* awlut.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = awlut.c; sourceTree = "<group>"; };
                 3124CAC6156BE48D00753214 /* fmtdy.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = fmtdy.c; sourceTree = "<group>"; };
@@ -161,7 +162,6 @@
                 31EEAC4E156AB3E300714D05 /* prmcan.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = prmcan.c; sourceTree = "<group>"; };
                 31EEAC4F156AB3E300714D05 /* protix.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = protix.c; sourceTree = "<group>"; };
                 31EEAC50156AB3E300714D05 /* protsgix.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = protsgix.c; sourceTree = "<group>"; };
-                31EEAC51156AB3E300714D05 /* ssan.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = ssan.c; sourceTree = "<group>"; };
                 31EEAC52156AB3E300714D05 /* than.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = than.c; sourceTree = "<group>"; };
                 31EEAC53156AB3E300714D05 /* vmix.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = vmix.c; sourceTree = "<group>"; };
                 31EEAC5B156AB41900714D05 /* poolamc.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = poolamc.c; sourceTree = "<group>"; };
@@ -245,7 +245,7 @@
                 31A47BA7156C1E6E0039B1C2 /* I6 */ = {
                         isa = PBXGroup;
                         children = (
-                                31EEAC51156AB3E300714D05 /* ssan.c */,
+                                3104AFA5156D27E7000A585A /* ssixi6.c */,
                         );
                         name = I6;
                         sourceTree = "<group>";
diff --git a/mps/code/ssixi6.c b/mps/code/ssixi6.c
new file mode 100644
index 00000000000..6732f850b3b
--- /dev/null
+++ b/mps/code/ssixi6.c
@@ -0,0 +1,111 @@
+/* ssixi6.c: UNIX/INTEL STACK SCANNING
+ *
+ * $Id$
+ * Copyright (c) 2001 Ravenbrook Limited.  See end of file for license.
+ *
+ *  This scans the stack and fixes the registers which may contain
+ *  roots.  See <design/thread-manager/>
+ *
+ *  This code was branched from ssixi3.c (32-bit Intel) initially for the
+ *  port to W3I6LL (Mac OS X on x86_64 with Clang).
+ *
+ *  This code is common to more than one Unix implementation on
+ *  Intel hardware (but is not portable Unix code).  According to Wikipedia,
+ *  all the non-Windows platforms use the System V AMD64 ABI.  See
+ *  .sources.callees.saves.
+ *
+ * SOURCES
+ *
+ * .sources.callees.saves:
+ *  "Registers %rbp, %rbx and %r12 through %r15 "belong" to the calling
+ *   function and the called function is required to preserve their values.
+ *   In other words, a called function must preserve these registers’ values
+ *   for its caller." -- System V AMD64 ABI
+ *  <http://x86-64.org/documentation/abi.pdf>
+ *
+ * ASSUMPTIONS
+ *
+ * .assume.align: The stack pointer is assumed to be aligned on a word
+ * boundary.
+ *
+ * .assume.asm.stack: The compiler must not do wacky things with the
+ * stack pointer around a call since we need to ensure that the
+ * callee-save regs are visible during TraceScanArea.
+ *
+ * .assume.asm.order: The volatile modifier should prevent movement
+ * of code, which might break .assume.asm.stack.
+ *
+ */
+
+
+#include "mpm.h"
+
+SRCID(ssixi6, "$Id$");
+
+
+/* .assume.asm.order */
+#define ASMV(x) __asm__ volatile (x)
+
+
+Res StackScan(ScanState ss, Addr *stackBot)
+{
+  Addr *stackTop;
+  Res res;
+
+  ASMV("push %rbp");
+  ASMV("push %rbx");
+  ASMV("push %r12");
+  ASMV("push %r13");
+  ASMV("push %r14");
+  ASMV("push %r15");
+  ASMV("mov %%rsp, %0" : "=r" (stackTop) :);    /* stackTop = esp */
+
+  AVER(AddrIsAligned((Addr)stackTop, sizeof(Addr)));  /* .assume.align */
+  res = TraceScanArea(ss, stackTop, stackBot);
+
+  ASMV("add $48, %rsp");  /* pop 6 regs to restore the stack pointer */
+
+  return res;
+}
+
+
+/* C. COPYRIGHT AND LICENSE
+ *
+ * Copyright (C) 2001-2002 Ravenbrook Limited <http://www.ravenbrook.com/>.
+ * All rights reserved.  This is an open source license.  Contact
+ * Ravenbrook for commercial licensing options.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ * 
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 
+ * 3. Redistributions in any form must be accompanied by information on how
+ * to obtain complete source code for this software and any accompanying
+ * software that uses this software.  The source code must either be
+ * included in the distribution or be available for no more than the cost
+ * of distribution plus a nominal fee, and must be freely redistributable
+ * under reasonable conditions.  For an executable file, complete source
+ * code means the source code for all modules it contains. It does not
+ * include source code for modules or files that typically accompany the
+ * major components of the operating system on which the executable file
+ * runs.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+ * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
+ * PURPOSE, OR NON-INFRINGEMENT, ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT HOLDERS AND CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */