Fix OSR for nested loops.

src/x64/builtins-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 1819 matching lines @@
 
   // -------------------------------------------
   // Dont adapt arguments.
   // -------------------------------------------
   __ bind(&dont_adapt_arguments);
   __ jmp(rdx);
 }
 
 
 void Builtins::Generate_OnStackReplacement(MacroAssembler* masm) {
-  // Get the loop depth of the stack guard check. This is recorded in
-  // a test(rax, depth) instruction right after the call.
-  Label stack_check;
-  __ movq(rbx, Operand(rsp, 0));  // return address
-  __ movzxbq(rbx, Operand(rbx, 1));  // depth
-
-  // Get the loop nesting level at which we allow OSR from the
-  // unoptimized code and check if we want to do OSR yet. If not we
-  // should perform a stack guard check so we can get interrupts while
-  // waiting for on-stack replacement.
   __ movq(rax, Operand(rbp, JavaScriptFrameConstants::kFunctionOffset));
-  __ movq(rcx, FieldOperand(rax, JSFunction::kSharedFunctionInfoOffset));
-  __ movq(rcx, FieldOperand(rcx, SharedFunctionInfo::kCodeOffset));
-  __ cmpb(rbx, FieldOperand(rcx, Code::kAllowOSRAtLoopNestingLevelOffset));
-  __ j(greater, &stack_check);
 
   // Pass the function to optimize as the argument to the on-stack
   // replacement runtime function.
   {
     FrameScope scope(masm, StackFrame::INTERNAL);
     __ push(rax);
     __ CallRuntime(Runtime::kCompileForOnStackReplacement, 1);
   }
 
   // If the result was -1 it means that we couldn't optimize the
   // function. Just return and continue in the unoptimized version.
   Label skip;
   __ SmiCompare(rax, Smi::FromInt(-1));
   __ j(not_equal, &skip, Label::kNear);
   __ ret(0);
 
-  // If we decide not to perform on-stack replacement we perform a
-  // stack guard check to enable interrupts.
-  __ bind(&stack_check);
-  Label ok;
-  __ CompareRoot(rsp, Heap::kStackLimitRootIndex);
-  __ j(above_equal, &ok, Label::kNear);
-
-  StackCheckStub stub;
-  __ TailCallStub(&stub);
-  if (FLAG_debug_code) {
-    __ Abort("Unreachable code: returned from tail call.");
-  }
-  __ bind(&ok);
-  __ ret(0);
-
   __ bind(&skip);
   // Untag the AST id and push it on the stack.
   __ SmiToInteger32(rax, rax);
   __ push(rax);
 
   // Generate the code for doing the frame-to-frame translation using
   // the deoptimizer infrastructure.
   Deoptimizer::EntryGenerator generator(masm, Deoptimizer::OSR);
   generator.Generate();
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64