Use count-based profiling exclusively.

src/x64/deoptimizer-x64.cc

 // Copyright 2012 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:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 98 matching lines @@
   if (FLAG_trace_deopt) {
     PrintF("[forced deoptimization: ");
     function->PrintName();
     PrintF(" / %" V8PRIxPTR "]\n", reinterpret_cast<intptr_t>(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;
 
 void Deoptimizer::PatchStackCheckCodeAt(Code* unoptimized_code,
                                         Address pc_after,
                                         Code* check_code,
                                         Code* replacement_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,
                                    replacement_code->entry());
 
   unoptimized_code->GetHeap()->incremental_marking()->RecordCodeTargetPatch(
       unoptimized_code, call_target_address, replacement_code);
 }
 
 
 void Deoptimizer::RevertStackCheckCodeAt(Code* unoptimized_code,
                                          Address pc_after,
                                          Code* check_code,
                                          Code* replacement_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_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());
 
   check_code->GetHeap()->incremental_marking()->RecordCodeTargetPatch(
       unoptimized_code, call_target_address, check_code);
 }
 
 
 static int LookupBailoutId(DeoptimizationInputData* data, BailoutId ast_id) {
   ByteArray* translations = data->TranslationByteArray();
@@ skipping 981 matching lines @@
   }
   __ bind(&done);
 }
 
 #undef __
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64