Refactored the code for entering and leaving exit frames (calls...

src/codegen-arm.cc

Index: src/codegen-arm.cc
===================================================================
--- src/codegen-arm.cc	(revision 353)
+++ src/codegen-arm.cc	(working copy)
@@ -1640,11 +1640,9 @@
   }
 
   // Call C built-in.
-  // r0 = argc.
+  // r0 = argc, r1 = argv
   __ mov(r0, Operand(r4));
-  // r1 = argv.
-  __ add(r1, fp, Operand(r4, LSL, kPointerSizeLog2));
-  __ add(r1, r1, Operand(ExitFrameConstants::kPPDisplacement - kPointerSize));
+  __ mov(r1, Operand(r6));

[iposva, 2008/09/23 07:51:28]

Please add r6 to the contract with calling code above.

 
   // TODO(1242173): To let the GC traverse the return address of the exit
   // frames, we need to know where the return address is. Right now,
@@ -1671,11 +1669,6 @@
   __ tst(r2, Operand(kFailureTagMask));
   __ b(eq, &failure_returned);
 
-  // clear top frame
-  __ mov(r3, Operand(0));
-  __ mov(ip, Operand(ExternalReference(Top::k_c_entry_fp_address)));
-  __ str(r3, MemOperand(ip));
-
   // Restore the memory copy of the registers by digging them out from
   // the stack.
   if (do_restore) {
@@ -1691,13 +1684,8 @@
   // sp: stack pointer
   // fp: frame pointer
   // pp: caller's parameter pointer pp  (restored as C callee-saved)
+  __ LeaveExitFrame();
 
-  // Restore current context from top and clear it in debug mode.
-  __ mov(r3, Operand(Top::context_address()));
-  __ ldr(cp, MemOperand(r3));
-  __ mov(sp, Operand(fp));  // respect ABI stack constraint
-  __ ldm(ia, sp, fp.bit() | sp.bit() | pc.bit());
-
   // check if we should retry or throw exception
   Label retry;
   __ bind(&failure_returned);
@@ -1744,42 +1732,19 @@
   // this by performing a garbage collection and retrying the
   // builtin once.
 
-  // Enter C frame
-  // Compute parameter pointer before making changes and save it as ip register
-  // so that it is restored as sp register on exit, thereby popping the args.
-  // ip = sp + kPointerSize*args_len;
-  __ add(ip, sp, Operand(r0, LSL, kPointerSizeLog2));
+  StackFrame::Type frame_type = is_debug_break
+      ? StackFrame::EXIT_DEBUG
+      : StackFrame::EXIT;
 
-  // push in reverse order:
-  // caller_fp, sp_on_exit, caller_pc
-  __ stm(db_w, sp, fp.bit() | ip.bit() | lr.bit());
-  __ mov(fp, Operand(sp));  // setup new frame pointer
+  // Enter the exit frame that transitions from JavaScript to C++.
+  __ EnterExitFrame(frame_type);
 
-  // Store the current context in top.
-  __ mov(ip, Operand(ExternalReference(Top::k_context_address)));
-  __ str(cp, MemOperand(ip));
-
-  // remember top frame
-  __ mov(ip, Operand(ExternalReference(Top::k_c_entry_fp_address)));
-  __ str(fp, MemOperand(ip));
-
-  // Push debug marker.
-  __ mov(ip, Operand(is_debug_break ? 1 : 0));
-  __ push(ip);
-
   if (is_debug_break) {
     // Save the state of all registers to the stack from the memory location.
     // Use sp as base to push.
     __ CopyRegistersFromMemoryToStack(sp, kJSCallerSaved);
   }
 
-  // move number of arguments (argc) into callee-saved register
-  __ mov(r4, Operand(r0));
-
-  // move pointer to builtin function into callee-saved register
-  __ mov(r5, Operand(r1));
-
-  // r0: result parameter for PerformGC, if any (setup below)
   // r4: number of arguments
   // r5: pointer to builtin function  (C callee-saved)