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

src/builtins/arm/builtins-arm.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_ARM
 
 #include "src/codegen.h"
 #include "src/debug/debug.h"
 #include "src/deoptimizer.h"
 #include "src/full-codegen/full-codegen.h"
@@ skipping 1352 matching lines @@
 }
 
 void Builtins::Generate_CompileLazy(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- r0 : argument count (preserved for callee)
   //  -- r3 : new target (preserved for callee)
   //  -- r1 : target function (preserved for callee)
   // -----------------------------------
   // First lookup code, maybe we don't need to compile!
   Label gotta_call_runtime, gotta_call_runtime_no_stack;
-  Label maybe_call_runtime;
   Label try_shared;
   Label loop_top, loop_bottom;
 
   Register argument_count = r0;
   Register closure = r1;
   Register new_target = r3;
   __ push(argument_count);
   __ push(new_target);
   __ push(closure);
 
@@ skipping 46 matching lines @@
                       kLRHasNotBeenSaved, kDontSaveFPRegs, EMIT_REMEMBERED_SET,
                       OMIT_SMI_CHECK);
   __ pop(index);
 
   // Code available?
   Register entry = r4;
   __ 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.
   __ pop(closure);
   // Store code entry in the closure.
   __ add(entry, entry, Operand(Code::kHeaderSize - kHeapObjectTag));
 
   Label install_optimized_code_and_tailcall;
   __ bind(&install_optimized_code_and_tailcall);

[Michael Starzinger, 2016/10/07 09:23:46]

nit: The {install_optimized_code_and_tailcall} label seems to be unused bu now.
Let's drop the label as well as the binding call. Probably applies to all
architectures.

[mvstanton, 2016/10/07 09:46:27]

Good catch, thanks! Done.

   __ str(entry, FieldMemOperand(closure, JSFunction::kCodeEntryOffset));
   __ RecordWriteCodeEntryField(closure, entry, r5);
 
   // Link the closure into the optimized function list.
   // r4 : code entry
   // r3 : native context
   // r1 : closure
   __ ldr(r5,
          ContextMemOperand(native_context, Context::OPTIMIZED_FUNCTIONS_LIST));
   __ str(r5, FieldMemOperand(closure, JSFunction::kNextFunctionLinkOffset));
@@ skipping 14 matching lines @@
   __ Jump(entry);
 
   __ bind(&loop_bottom);
   __ sub(index, index, Operand(Smi::FromInt(SharedFunctionInfo::kEntryLength)));
   __ cmp(index, Operand(Smi::FromInt(1)));
   __ b(gt, &loop_top);
 
   // We found neither literals nor code.
   __ jmp(&gotta_call_runtime);
 
-  __ bind(&maybe_call_runtime);
+  __ bind(&try_shared);
   __ pop(closure);
-
-  // 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));
-  __ jmp(&install_optimized_code_and_tailcall);
-
-  __ bind(&try_shared);
   __ pop(new_target);
   __ pop(argument_count);
   // Is the full code valid?
   __ ldr(entry,
          FieldMemOperand(closure, JSFunction::kSharedFunctionInfoOffset));
   __ ldr(entry, FieldMemOperand(entry, SharedFunctionInfo::kCodeOffset));
   __ ldr(r5, FieldMemOperand(entry, Code::kFlagsOffset));
   __ and_(r5, r5, Operand(Code::KindField::kMask));
   __ mov(r5, Operand(r5, LSR, Code::KindField::kShift));
   __ cmp(r5, Operand(Code::BUILTIN));
@@ skipping 1416 matching lines @@
     __ bkpt(0);
   }
 }
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_ARM