Use count-based profiling exclusively.

src/x64/deoptimizer-x64.cc

Index: src/x64/deoptimizer-x64.cc
diff --git a/src/x64/deoptimizer-x64.cc b/src/x64/deoptimizer-x64.cc
index 20f507bdfbf65e75bbfec19b5e8fb3939967d0e7..0da9e86f0f5ca3eb9063eea6d80f905ab65d8b24 100644
--- a/src/x64/deoptimizer-x64.cc
+++ b/src/x64/deoptimizer-x64.cc
@@ -116,8 +116,6 @@ void Deoptimizer::DeoptimizeFunction(JSFunction* function) {
 
 static const byte kJnsInstruction = 0x79;
 static const byte kJnsOffset = 0x1f;
-static const byte kJaeInstruction = 0x73;
-static const byte kJaeOffset = 0x07;
 static const byte kCallInstruction = 0xe8;
 static const byte kNopByteOne = 0x66;
 static const byte kNopByteTwo = 0x90;
@@ -129,31 +127,26 @@ void Deoptimizer::PatchStackCheckCodeAt(Code* unoptimized_code,
   Address call_target_address = pc_after - kIntSize;
   ASSERT_EQ(check_code->entry(),
             Assembler::target_address_at(call_target_address));
-  // The stack check code matches the pattern:
+  // The back edge bookkeeping code matches the pattern:
   //
-  //     cmp rsp, <limit>
-  //     jae ok
+  //     add <profiling_counter>, <-delta>
+  //     jns ok
   //     call <stack guard>
   //     test rax, <loop nesting depth>
   // ok: ...
   //
   // We will patch away the branch so the code is:
   //
-  //     cmp rsp, <limit>  ;; Not changed
+  //     add <profiling_counter>, <-delta>  ;; Not changed
   //     nop
   //     nop
   //     call <on-stack replacment>
   //     test rax, <loop nesting depth>
   // ok:
   //
-  if (FLAG_count_based_interrupts) {
-    ASSERT_EQ(kJnsInstruction,       *(call_target_address - 3));
-    ASSERT_EQ(kJnsOffset,            *(call_target_address - 2));
-  } else {
-    ASSERT_EQ(kJaeInstruction,       *(call_target_address - 3));
-    ASSERT_EQ(kJaeOffset,            *(call_target_address - 2));
-  }
-  ASSERT_EQ(kCallInstruction,        *(call_target_address - 1));
+  ASSERT_EQ(kJnsInstruction,  *(call_target_address - 3));
+  ASSERT_EQ(kJnsOffset,       *(call_target_address - 2));
+  ASSERT_EQ(kCallInstruction, *(call_target_address - 1));
   *(call_target_address - 3) = kNopByteOne;
   *(call_target_address - 2) = kNopByteTwo;
   Assembler::set_target_address_at(call_target_address,
@@ -176,13 +169,8 @@ void Deoptimizer::RevertStackCheckCodeAt(Code* unoptimized_code,
   ASSERT_EQ(kNopByteOne,      *(call_target_address - 3));
   ASSERT_EQ(kNopByteTwo,      *(call_target_address - 2));
   ASSERT_EQ(kCallInstruction, *(call_target_address - 1));
-  if (FLAG_count_based_interrupts) {
-    *(call_target_address - 3) = kJnsInstruction;
-    *(call_target_address - 2) = kJnsOffset;
-  } else {
-    *(call_target_address - 3) = kJaeInstruction;
-    *(call_target_address - 2) = kJaeOffset;
-  }
+  *(call_target_address - 3) = kJnsInstruction;
+  *(call_target_address - 2) = kJnsOffset;
   Assembler::set_target_address_at(call_target_address,
                                    check_code->entry());