Initial support for count-based profiling

src/ia32/deoptimizer-ia32.cc

Index: src/ia32/deoptimizer-ia32.cc
diff --git a/src/ia32/deoptimizer-ia32.cc b/src/ia32/deoptimizer-ia32.cc
index 14f26757e9232fc066d279af189e76d2394739af..921ee5fa03ed43e2232b76f2102ebbfa18a6e19d 100644
--- a/src/ia32/deoptimizer-ia32.cc
+++ b/src/ia32/deoptimizer-ia32.cc
@@ -228,9 +228,15 @@ void Deoptimizer::PatchStackCheckCodeAt(Code* unoptimized_code,
   //     call <on-stack replacment>
   //     test eax, <loop nesting depth>
   // ok:
-  ASSERT(*(call_target_address - 3) == 0x73 &&  // jae
-         *(call_target_address - 2) == 0x07 &&  // offset
-         *(call_target_address - 1) == 0xe8);   // call
+
+  if (FLAG_count_based_interrupts) {
+    ASSERT(*(call_target_address - 3) == 0x79);  // jns
+    ASSERT(*(call_target_address - 2) == 0x11);  // offset

[Vyacheslav Egorov (Chromium), 2012/02/14 12:52:47]

Please name magical constants. they are duplicated in the code.

[Jakob Kummerow, 2012/02/14 13:54:45]

Done.

+  } else {
+    ASSERT(*(call_target_address - 3) == 0x73);  // jae
+    ASSERT(*(call_target_address - 2) == 0x07);  // offset
+  }
+  ASSERT(*(call_target_address - 1) == 0xe8);    // call
   *(call_target_address - 3) = 0x66;  // 2 byte nop part 1
   *(call_target_address - 2) = 0x90;  // 2 byte nop part 2
   Assembler::set_target_address_at(call_target_address,
@@ -248,13 +254,19 @@ void Deoptimizer::RevertStackCheckCodeAt(Code* unoptimized_code,
   Address call_target_address = pc_after - kIntSize;
   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) == 0x66 &&  // 2 byte nop part 1
          *(call_target_address - 2) == 0x90 &&  // 2 byte nop part 2
          *(call_target_address - 1) == 0xe8);   // call
-  *(call_target_address - 3) = 0x73;  // jae
-  *(call_target_address - 2) = 0x07;  // offset
+  if (FLAG_count_based_interrupts) {
+    *(call_target_address - 3) = 0x79;  // jns
+    *(call_target_address - 2) = 0x11;  // offset
+  } else {
+    *(call_target_address - 3) = 0x73;  // jae
+    *(call_target_address - 2) = 0x07;  // offset
+  }
   Assembler::set_target_address_at(call_target_address,
                                    check_code->entry());