First draft of the sh4 port

src/sh4/frames-sh4.h

Index: src/sh4/frames-sh4.h
diff --git a/src/x64/frames-x64.h b/src/sh4/frames-sh4.h
similarity index 73%
copy from src/x64/frames-x64.h
copy to src/sh4/frames-sh4.h
index 3e3d63d62b917f4c2547dd353cbeec6b7128ef9e..79d7e633b41ee0c5a06d0fdb6963d15f3f199ed2 100644
--- a/src/x64/frames-x64.h
+++ b/src/sh4/frames-sh4.h
@@ -1,4 +1,4 @@
-// Copyright 2012 the V8 project authors. All rights reserved.
+// Copyright 2011-2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
@@ -25,29 +25,55 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-#ifndef V8_X64_FRAMES_X64_H_
-#define V8_X64_FRAMES_X64_H_
+#ifndef V8_SH4_FRAMES_SH4_H_
+#define V8_SH4_FRAMES_SH4_H_
+
+#include "memory.h"
 
 namespace v8 {
 namespace internal {
 
+
+// Register lists
+// Note that the bit values must match those used in actual instruction encoding
 const int kNumRegs = 16;
+
+
+// Caller-saved registers
 const RegList kJSCallerSaved =
-    1 << 0 |  // rax
-    1 << 1 |  // rcx
-    1 << 2 |  // rdx
-    1 << 3 |  // rbx - used as a caller-saved register in JavaScript code
-    1 << 7;   // rdi - callee function
+  1 << 0 |      // r0
+  1 << 1 |      // r1
+  1 << 2 |      // r2
+  1 << 3 |      // r3
+  1 << 4 |      // r4
+  1 << 5 |      // r5
+  1 << 6 |      // r6
+  1 << 7;       // r7
+
+const int kNumJSCallerSaved = 8;
+
+// Callee-saved registers preserved when switching from C to JavaScript
+const RegList kCalleeSaved =
+  1 <<  8  |  //  r8
+  1 <<  9  |  //  r9
+  1 <<  10 |  //  r10
+  1 <<  11 |  //  r11
+  1 <<  12 |  //  r12 (roots in JS)
+  1 <<  13 |  //  r13 (cp in JS)
+  1 <<  14;   //  r14 (fp in JS)
+
+const int kNumCalleeSaved = 7;
 
-const int kNumJSCallerSaved = 5;
 
 typedef Object* JSCallerSavedBuffer[kNumJSCallerSaved];
 
+
 // Number of registers for which space is reserved in safepoints.
 const int kNumSafepointRegisters = 16;
 
 // ----------------------------------------------------
 
+
 class StackHandlerConstants : public AllStatic {
  public:
   static const int kNextOffset     = 0 * kPointerSize;
@@ -62,26 +88,23 @@ class StackHandlerConstants : public AllStatic {
 
 class EntryFrameConstants : public AllStatic {
  public:
-#ifdef _WIN64
-  static const int kCallerFPOffset      = -10 * kPointerSize;
-#else
-  static const int kCallerFPOffset      = -8 * kPointerSize;
-#endif
-  static const int kArgvOffset          = 6 * kPointerSize;
+  static const int kCallerFPOffset      = -3 * kPointerSize;
 };
 
 
 class ExitFrameConstants : public AllStatic {
  public:
-  static const int kCodeOffset      = -2 * kPointerSize;
-  static const int kSPOffset        = -1 * kPointerSize;
+  static const int kCodeOffset = -2 * kPointerSize;
+  static const int kSPOffset = -1 * kPointerSize;
 
-  static const int kCallerFPOffset  = +0 * kPointerSize;
-  static const int kCallerPCOffset  = +1 * kPointerSize;
+  // The caller fields are below the frame pointer on the stack.
+  static const int kCallerFPOffset = 0 * kPointerSize;
+  // The calling JS function is below FP.
+  static const int kCallerPCOffset = 1 * kPointerSize;
 
   // FP-relative displacement of the caller's SP.  It points just
   // below the saved PC.
-  static const int kCallerSPDisplacement = +2 * kPointerSize;
+  static const int kCallerSPDisplacement = 2 * kPointerSize;
 };
 
 
@@ -94,8 +117,8 @@ class StandardFrameConstants : public AllStatic {
   static const int kMarkerOffset      = -2 * kPointerSize;
   static const int kContextOffset     = -1 * kPointerSize;
   static const int kCallerFPOffset    =  0 * kPointerSize;
-  static const int kCallerPCOffset    = +1 * kPointerSize;
-  static const int kCallerSPOffset    = +2 * kPointerSize;
+  static const int kCallerPCOffset    =  1 * kPointerSize;
+  static const int kCallerSPOffset    =  2 * kPointerSize;
 };
 
 
@@ -131,6 +154,7 @@ inline Object* JavaScriptFrame::function_slot_object() const {
   return Memory::Object_at(fp() + offset);
 }
 
+
 } }  // namespace v8::internal
 
-#endif  // V8_X64_FRAMES_X64_H_
+#endif  // V8_SH4_FRAMES_SH4_H_