From 6e116da468e0909ffcfb97065c8a3ff4efb9a6c5 Mon Sep 17 00:00:00 2001
From: Gareth Rees <gdr@ravenbrook.com>
Date: Tue, 4 Jun 2019 14:09:05 +0100
Subject: [PATCH] Restore assembly code (removed in change 194595) for spilling
 callee-save registers on fr and li platforms.

Copied from Perforce
 Change: 196178
---
 mps/code/ss.h | 65 +++++++++++++++++++++++++++++++++++++--------------
 1 file changed, 48 insertions(+), 17 deletions(-)

diff --git a/mps/code/ss.h b/mps/code/ss.h
index 59543ae7048..513b4e73237 100644
--- a/mps/code/ss.h
+++ b/mps/code/ss.h
@@ -1,7 +1,7 @@
 /* ss.h: STACK SCANNING
  *
  * $Id$
- * Copyright (c) 2001-2018 Ravenbrook Limited.  See end of file for license.
+ * Copyright (c) 2001-2019 Ravenbrook Limited.  See end of file for license.
  *
  * This module saves the mutator context on entry to the MPS, and
  * provides functions for decoding the context and scanning the root
@@ -13,21 +13,12 @@
 
 #include "mpm.h"
 
+
+/* StackContext -- some of the mutator's state */
+
+typedef struct StackContextStruct StackContextStruct;
+
      
-/* StackContext -- some of the mutator's state
- *
- * The jumpBuffer is used to capture most of the mutator's state on
- * entry to the MPS, but can't capture it all.  See
- * <design/stack-scan#.sol.setjmp.scan>.
- */
-
-#include <setjmp.h>
-
-typedef struct StackContextStruct {
-  jmp_buf jumpBuffer;
-} StackContextStruct;
-
-
 /* StackHot -- capture a hot stack pointer
  *
  * Sets *stackOut to a stack pointer that includes the current frame.
@@ -59,6 +50,44 @@ void StackHot(void **stackOut);
 
 /* STACK_CONTEXT_SAVE -- save the callee-saves and stack pointer */
 
+#if (defined(MPS_OS_FR) || defined(MPS_OS_LI)) && defined(MPS_ARCH_I3)
+
+struct StackContextStruct {
+  Word calleeSave[4];
+};
+
+#define STACK_CONTEXT_SAVE(sc)                                       \
+  BEGIN                                                              \
+    __asm__ volatile ("mov %%ebx, %0" : "=m" ((sc)->calleeSave[0])); \
+    __asm__ volatile ("mov %%esi, %0" : "=m" ((sc)->calleeSave[1])); \
+    __asm__ volatile ("mov %%edi, %0" : "=m" ((sc)->calleeSave[2])); \
+    __asm__ volatile ("mov %%ebp, %0" : "=m" ((sc)->calleeSave[3])); \
+  END
+
+#elif (defined(MPS_OS_FR) || defined(MPS_OS_LI)) && defined(MPS_ARCH_I6)
+
+struct StackContextStruct {
+  Word calleeSave[6];
+};
+
+#define STACK_CONTEXT_SAVE(sc)                                       \
+  BEGIN                                                              \
+    __asm__ volatile ("mov %%rbp, %0" : "=m" ((sc)->calleeSave[0])); \
+    __asm__ volatile ("mov %%rbx, %0" : "=m" ((sc)->calleeSave[1])); \
+    __asm__ volatile ("mov %%r12, %0" : "=m" ((sc)->calleeSave[2])); \
+    __asm__ volatile ("mov %%r13, %0" : "=m" ((sc)->calleeSave[3])); \
+    __asm__ volatile ("mov %%r14, %0" : "=m" ((sc)->calleeSave[4])); \
+    __asm__ volatile ("mov %%r15, %0" : "=m" ((sc)->calleeSave[5])); \
+  END
+
+#else /* jmp_buf platforms */
+
+#include <setjmp.h>
+
+struct StackContextStruct {
+  jmp_buf jumpBuffer;
+};
+
 #if defined(MPS_OS_XC)
 
 /* We call _setjmp rather than setjmp because we can be confident what
@@ -74,7 +103,9 @@ void StackHot(void **stackOut);
 
 #define STACK_CONTEXT_SAVE(sc) ((void)setjmp((sc)->jumpBuffer))
 
-#endif /* platform defines */
+#endif /* jmp_buf platforms */
+
+#endif /* platform specific code */
 
 
 /* StackScan -- scan the mutator's stack and registers
@@ -92,7 +123,7 @@ extern Res StackScan(ScanState ss, void *stackCold,
 
 /* C. COPYRIGHT AND LICENSE
  *
- * Copyright (C) 2001-2018 Ravenbrook Limited <https://www.ravenbrook.com/>.
+ * Copyright (C) 2001-2019 Ravenbrook Limited <https://www.ravenbrook.com/>.
  * All rights reserved.  This is an open source license.  Contact
  * Ravenbrook for commercial licensing options.
  *