Reland "[turbofan] Discard the shared code entry in the optimized code map."

src/builtins/x64/builtins-x64.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/code-factory.h"
 #include "src/codegen.h"
 #include "src/deoptimizer.h"
 #include "src/full-codegen/full-codegen.h"
@@ skipping 1013 matching lines @@
 }
 
 void Builtins::Generate_CompileLazy(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- rax : argument count (preserved for callee)
   //  -- rdx : new target (preserved for callee)
   //  -- rdi : target function (preserved for callee)
   // -----------------------------------
   // First lookup code, maybe we don't need to compile!
   Label gotta_call_runtime;
-  Label maybe_call_runtime;
   Label try_shared;
   Label loop_top, loop_bottom;
 
   Register closure = rdi;
   Register map = r8;
   Register index = r9;
   __ movp(map, FieldOperand(closure, JSFunction::kSharedFunctionInfoOffset));
   __ movp(map, FieldOperand(map, SharedFunctionInfo::kOptimizedCodeMapOffset));
   __ SmiToInteger32(index, FieldOperand(map, FixedArray::kLengthOffset));
   __ cmpl(index, Immediate(2));
@@ skipping 33 matching lines @@
   __ movp(FieldOperand(closure, JSFunction::kLiteralsOffset), temp);
   __ movp(r15, index);
   __ RecordWriteField(closure, JSFunction::kLiteralsOffset, temp, r15,
                       kDontSaveFPRegs, EMIT_REMEMBERED_SET, OMIT_SMI_CHECK);
 
   // Code available?
   Register entry = rcx;
   __ movp(entry, FieldOperand(map, index, times_pointer_size,
                               SharedFunctionInfo::kOffsetToPreviousCachedCode));
   __ movp(entry, FieldOperand(entry, WeakCell::kValueOffset));
-  __ JumpIfSmi(entry, &maybe_call_runtime);
+  __ JumpIfSmi(entry, &try_shared);
 
   // Found literals and code. Get them into the closure and return.
   __ leap(entry, FieldOperand(entry, Code::kHeaderSize));
-
-  Label install_optimized_code_and_tailcall;
-  __ bind(&install_optimized_code_and_tailcall);
   __ movp(FieldOperand(closure, JSFunction::kCodeEntryOffset), entry);
   __ RecordWriteCodeEntryField(closure, entry, r15);
 
   // Link the closure into the optimized function list.
   // rcx : code entry (entry)
   // r14 : native context
   // rdx : new target
   // rdi : closure
   __ movp(rbx,
           ContextOperand(native_context, Context::OPTIMIZED_FUNCTIONS_LIST));
@@ skipping 12 matching lines @@
   __ jmp(entry);
 
   __ bind(&loop_bottom);
   __ subl(index, Immediate(SharedFunctionInfo::kEntryLength));
   __ cmpl(index, Immediate(1));
   __ j(greater, &loop_top);
 
   // We found neither literals nor code.
   __ jmp(&gotta_call_runtime);
 
-  __ bind(&maybe_call_runtime);
-
-  // Last possibility. Check the context free optimized code map entry.
-  __ movp(entry, FieldOperand(map, FixedArray::kHeaderSize +
-                                       SharedFunctionInfo::kSharedCodeIndex));
-  __ movp(entry, FieldOperand(entry, WeakCell::kValueOffset));
-  __ JumpIfSmi(entry, &try_shared);
-
-  // Store code entry in the closure.
-  __ leap(entry, FieldOperand(entry, Code::kHeaderSize));
-  __ jmp(&install_optimized_code_and_tailcall);
-
   __ bind(&try_shared);
   // Is the full code valid?
   __ movp(entry, FieldOperand(closure, JSFunction::kSharedFunctionInfoOffset));
   __ movp(entry, FieldOperand(entry, SharedFunctionInfo::kCodeOffset));
   __ movl(rbx, FieldOperand(entry, Code::kFlagsOffset));
   __ andl(rbx, Immediate(Code::KindField::kMask));
   __ shrl(rbx, Immediate(Code::KindField::kShift));
   __ cmpl(rbx, Immediate(Code::BUILTIN));
   __ j(equal, &gotta_call_runtime);
   // Yes, install the full code.
@@ skipping 1940 matching lines @@
 void Builtins::Generate_InterpreterOnStackReplacement(MacroAssembler* masm) {
   Generate_OnStackReplacementHelper(masm, true);
 }
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64