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

src/builtins/arm64/builtins-arm64.cc

 // Copyright 2013 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_ARM64
 
 #include "src/arm64/frames-arm64.h"
 #include "src/codegen.h"
 #include "src/debug/debug.h"
 #include "src/deoptimizer.h"
@@ skipping 1363 matching lines @@
 }
 
 void Builtins::Generate_CompileLazy(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- x0 : argument count (preserved for callee)
   //  -- x3 : new target (preserved for callee)
   //  -- x1 : 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 = x1;
   Register map = x13;
   Register index = x2;
   __ Ldr(map, FieldMemOperand(closure, JSFunction::kSharedFunctionInfoOffset));
   __ Ldr(map,
          FieldMemOperand(map, SharedFunctionInfo::kOptimizedCodeMapOffset));
   __ Ldrsw(index, UntagSmiFieldMemOperand(map, FixedArray::kLengthOffset));
@@ skipping 37 matching lines @@
   __ RecordWriteField(closure, JSFunction::kLiteralsOffset, temp, x7,
                       kLRHasNotBeenSaved, kDontSaveFPRegs, EMIT_REMEMBERED_SET,
                       OMIT_SMI_CHECK);
 
   // Code available?
   Register entry = x7;
   __ Ldr(entry,
          FieldMemOperand(array_pointer,
                          SharedFunctionInfo::kOffsetToPreviousCachedCode));
   __ Ldr(entry, FieldMemOperand(entry, WeakCell::kValueOffset));
-  __ JumpIfSmi(entry, &maybe_call_runtime);
+  __ JumpIfSmi(entry, &try_shared);
 
   // Found literals and code. Get them into the closure and return.
   __ Add(entry, entry, Operand(Code::kHeaderSize - kHeapObjectTag));
-
-  Label install_optimized_code_and_tailcall;
-  __ Bind(&install_optimized_code_and_tailcall);
   __ Str(entry, FieldMemOperand(closure, JSFunction::kCodeEntryOffset));
   __ RecordWriteCodeEntryField(closure, entry, x5);
 
   // Link the closure into the optimized function list.
   // x7 : code entry
   // x4 : native context
   // x1 : closure
   __ Ldr(x8,
          ContextMemOperand(native_context, Context::OPTIMIZED_FUNCTIONS_LIST));
   __ Str(x8, FieldMemOperand(closure, JSFunction::kNextFunctionLinkOffset));
@@ skipping 10 matching lines @@
   __ Jump(entry);
 
   __ Bind(&loop_bottom);
   __ Sub(index, index, Operand(SharedFunctionInfo::kEntryLength));
   __ Cmp(index, Operand(1));
   __ B(gt, &loop_top);
 
   // We found neither literals nor code.
   __ B(&gotta_call_runtime);
 
-  __ Bind(&maybe_call_runtime);
-
-  // Last possibility. Check the context free optimized code map entry.
-  __ Ldr(entry, FieldMemOperand(map, FixedArray::kHeaderSize +
-                                         SharedFunctionInfo::kSharedCodeIndex));
-  __ Ldr(entry, FieldMemOperand(entry, WeakCell::kValueOffset));
-  __ JumpIfSmi(entry, &try_shared);
-
-  // Store code entry in the closure.
-  __ Add(entry, entry, Operand(Code::kHeaderSize - kHeapObjectTag));
-  __ B(&install_optimized_code_and_tailcall);
-
   __ Bind(&try_shared);
   // Is the full code valid?
   __ Ldr(entry,
          FieldMemOperand(closure, JSFunction::kSharedFunctionInfoOffset));
   __ Ldr(entry, FieldMemOperand(entry, SharedFunctionInfo::kCodeOffset));
   __ Ldr(x5, FieldMemOperand(entry, Code::kFlagsOffset));
   __ and_(x5, x5, Operand(Code::KindField::kMask));
   __ Mov(x5, Operand(x5, LSR, Code::KindField::kShift));
   __ Cmp(x5, Operand(Code::BUILTIN));
   __ B(eq, &gotta_call_runtime);
@@ skipping 1521 matching lines @@
     __ Unreachable();
   }
 }
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_ARM