Extract platform independent part of RevertStackCheckCode.

BUG=none
TEST=none

Review URL: http://codereview.chromium.org/6349046

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6572 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/deoptimizer-arm.cc

@@ -112,16 +112,16 @@ void Deoptimizer::DeoptimizeFunction(JSFunction* function) {
 }
 
 
-void Deoptimizer::PatchStackCheckAt(Address pc_after,
-                                    Code* check_code,
-                                    Code* replacement_code) {
+void Deoptimizer::PatchStackCheckCodeAt(Address pc_after,
+                                        Code* check_code,
+                                        Code* replacement_code) {
   UNIMPLEMENTED();
 }
 
 
-void Deoptimizer::RevertStackCheckCode(Code* unoptimized_code,
-                                       Code* check_code,
-                                       Code* replacement_code) {
+void Deoptimizer::RevertStackCheckCodeAt(Address pc_after,
+                                         Code* check_code,
+                                         Code* replacement_code) {
   UNIMPLEMENTED();
 }
 

src/deoptimizer.cc

@@ -823,7 +823,26 @@ void Deoptimizer::PatchStackCheckCode(Code* unoptimized_code,
   for (uint32_t i = 0; i < table_length; ++i) {
     uint32_t pc_offset = Memory::uint32_at(stack_check_cursor + kIntSize);
     Address pc_after = unoptimized_code->instruction_start() + pc_offset;
-    PatchStackCheckAt(pc_after, check_code, replacement_code);
+    PatchStackCheckCodeAt(pc_after, check_code, replacement_code);
+    stack_check_cursor += 2 * kIntSize;
+  }
+}
+
+
+void Deoptimizer::RevertStackCheckCode(Code* unoptimized_code,
+                                       Code* check_code,
+                                       Code* replacement_code) {
+  // Iterate over the stack check table and revert the patched
+  // stack check calls.
+  ASSERT(unoptimized_code->kind() == Code::FUNCTION);
+  Address stack_check_cursor = unoptimized_code->instruction_start() +
+      unoptimized_code->stack_check_table_start();
+  uint32_t table_length = Memory::uint32_at(stack_check_cursor);
+  stack_check_cursor += kIntSize;
+  for (uint32_t i = 0; i < table_length; ++i) {
+    uint32_t pc_offset = Memory::uint32_at(stack_check_cursor + kIntSize);
+    Address pc_after = unoptimized_code->instruction_start() + pc_offset;
+    RevertStackCheckCodeAt(pc_after, check_code, replacement_code);
     stack_check_cursor += 2 * kIntSize;
   }
 }

src/deoptimizer.h

@@ -136,9 +136,9 @@ class Deoptimizer : public Malloced {
 
   // Patch stack guard check at instruction before pc_after in
   // the unoptimized code to unconditionally call replacement_code.
-  static void PatchStackCheckAt(Address pc_after,
-                                Code* check_code,
-                                Code* replacement_code);
+  static void PatchStackCheckCodeAt(Address pc_after,
+                                    Code* check_code,
+                                    Code* replacement_code);
 
   // Change all patched stack guard checks in the unoptimized code
   // back to a normal stack guard check.
@@ -146,6 +146,12 @@ class Deoptimizer : public Malloced {
                                    Code* check_code,
                                    Code* replacement_code);
 
+  // Change all patched stack guard checks in the unoptimized code
+  // back to a normal stack guard check.
+  static void RevertStackCheckCodeAt(Address pc_after,
+                                     Code* check_code,
+                                     Code* replacement_code);
+
   ~Deoptimizer();
 
   void InsertHeapNumberValues(int index, JavaScriptFrame* frame);

src/ia32/deoptimizer-ia32.cc

@@ -147,9 +147,9 @@ void Deoptimizer::DeoptimizeFunction(JSFunction* function) {
 }
 
 
-void Deoptimizer::PatchStackCheckAt(Address pc_after,
-                                    Code* check_code,
-                                    Code* replacement_code) {
+void Deoptimizer::PatchStackCheckCodeAt(Address pc_after,
+                                        Code* check_code,
+                                        Code* replacement_code) {
     Address call_target_address = pc_after - kPointerSize;
     ASSERT(check_code->entry() ==
            Assembler::target_address_at(call_target_address));
@@ -179,26 +179,21 @@ void Deoptimizer::PatchStackCheckAt(Address pc_after,
 }
 
 
-void Deoptimizer::RevertStackCheckCode(Code* unoptimized_code,
-                                       Code* check_code,
-                                       Code* replacement_code) {
-  // Iterate the unoptimized code and revert all the patched stack checks.
-  for (RelocIterator it(unoptimized_code, RelocInfo::kCodeTargetMask);
-       !it.done();
-       it.next()) {
-    RelocInfo* rinfo = it.rinfo();
-    if (rinfo->target_address() == replacement_code->entry()) {
-      // 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) = 0x07;  // offset
-      rinfo->set_target_address(check_code->entry());
-    }
-  }
+void Deoptimizer::RevertStackCheckCodeAt(Address pc_after,
+                                         Code* check_code,
+                                         Code* replacement_code) {
+  Address call_target_address = pc_after - kPointerSize;
+  ASSERT(replacement_code->entry() ==
+         Assembler::target_address_at(call_target_address));
+  // Replace the nops from patching (Deoptimizer::PatchStackCheckCode) to
+  // restore the conditional branch.
+  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) = 0x07;  // offset
+  Assembler::set_target_address_at(call_target_address,
+                                   check_code->entry());
 }
 
 

src/x64/deoptimizer-x64.cc

@@ -107,16 +107,16 @@ void Deoptimizer::DeoptimizeFunction(JSFunction* function) {
 }
 
 
-void Deoptimizer::PatchStackCheckAt(Address pc_after,
-                                    Code* check_code,
-                                    Code* replacement_code) {
+void Deoptimizer::PatchStackCheckCodeAt(Address pc_after,
+                                        Code* check_code,
+                                        Code* replacement_code) {
   UNIMPLEMENTED();
 }
 
 
-void Deoptimizer::RevertStackCheckCode(Code* unoptimized_code,
-                                       Code* check_code,
-                                       Code* replacement_code) {
+void Deoptimizer::RevertStackCheckCodeAt(Address pc_after,
+                                         Code* check_code,
+                                         Code* replacement_code) {
   UNIMPLEMENTED();
 }