[Isolates] Merge from bleeding_edge to isolates, revisions 6100-6300.

src/ia32/deoptimizer-ia32.cc

Index: src/ia32/deoptimizer-ia32.cc
===================================================================
--- src/ia32/deoptimizer-ia32.cc	(revision 6941)
+++ src/ia32/deoptimizer-ia32.cc	(working copy)
@@ -1,4 +1,4 @@
-// Copyright 2010 the V8 project authors. All rights reserved.
+// Copyright 2011 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:
@@ -27,6 +27,8 @@
 
 #include "v8.h"
 
+#if defined(V8_TARGET_ARCH_IA32)
+
 #include "codegen.h"
 #include "deoptimizer.h"
 #include "full-codegen.h"
@@ -56,8 +58,9 @@
   SafepointTable table(function->code());
   for (unsigned i = 0; i < table.length(); i++) {
     unsigned pc_offset = table.GetPcOffset(i);
-    int deoptimization_index = table.GetDeoptimizationIndex(i);
-    int gap_code_size = table.GetGapCodeSize(i);
+    SafepointEntry safepoint_entry = table.GetEntry(i);
+    int deoptimization_index = safepoint_entry.deoptimization_index();
+    int gap_code_size = safepoint_entry.gap_code_size();
 #ifdef DEBUG
     // Destroy the code which is not supposed to run again.
     unsigned instructions = pc_offset - last_pc_offset;
@@ -106,23 +109,25 @@
 
 void Deoptimizer::PatchStackCheckCode(RelocInfo* rinfo,
                                       Code* replacement_code) {
-  // The stack check code matches the pattern (on ia32, for example):
+  // The stack check code matches the pattern:
   //
   //     cmp esp, <limit>
   //     jae ok
   //     call <stack guard>
+  //     test eax, <loop nesting depth>
   // ok: ...
   //
-  // We will patch the code to:
+  // We will patch away the branch so the code is:
   //
   //     cmp esp, <limit>  ;; Not changed
   //     nop
   //     nop
   //     call <on-stack replacment>
+  //     test eax, <loop nesting depth>
   // ok:
   Address call_target_address = rinfo->pc();
   ASSERT(*(call_target_address - 3) == 0x73 &&  // jae
-         *(call_target_address - 2) == 0x05 &&  // offset
+         *(call_target_address - 2) == 0x07 &&  // offset
          *(call_target_address - 1) == 0xe8);   // call
   *(call_target_address - 3) = 0x90;  // nop
   *(call_target_address - 2) = 0x90;  // nop
@@ -131,12 +136,14 @@
 
 
 void Deoptimizer::RevertStackCheckCode(RelocInfo* rinfo, Code* check_code) {
+  // Replace the nops from patching (Deoptimizer::PatchStackCheckCode) to
+  // restore the conditional branch.
   Address call_target_address = rinfo->pc();
   ASSERT(*(call_target_address - 3) == 0x90 &&  // nop
          *(call_target_address - 2) == 0x90 &&  // nop
          *(call_target_address - 1) == 0xe8);   // call
   *(call_target_address - 3) = 0x73;  // jae
-  *(call_target_address - 2) = 0x05;  // offset
+  *(call_target_address - 2) = 0x07;  // offset
   rinfo->set_target_address(check_code->entry());
 }
 
@@ -616,3 +623,5 @@
 
 
 } }  // namespace v8::internal
+
+#endif  // V8_TARGET_ARCH_IA32