PPC/s390: Reland "[turbofan] Discard the shared code entry in the optimized code map."

src/builtins/ppc/builtins-ppc.cc

 // Copyright 2014 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_PPC
 
 #include "src/codegen.h"
 #include "src/debug/debug.h"
 #include "src/deoptimizer.h"
 #include "src/full-codegen/full-codegen.h"
@@ skipping 1380 matching lines @@
 }
 
 void Builtins::Generate_CompileLazy(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- r3 : argument count (preserved for callee)
   //  -- r6 : new target (preserved for callee)
   //  -- r4 : 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 = r4;
   Register map = r9;
   Register index = r5;
   __ LoadP(map,
            FieldMemOperand(closure, JSFunction::kSharedFunctionInfoOffset));
   __ LoadP(map,
            FieldMemOperand(map, SharedFunctionInfo::kOptimizedCodeMapOffset));
@@ skipping 41 matching lines @@
   __ RecordWriteField(closure, JSFunction::kLiteralsOffset, temp, r7,
                       kLRHasNotBeenSaved, kDontSaveFPRegs, EMIT_REMEMBERED_SET,
                       OMIT_SMI_CHECK);
 
   // Code available?
   Register entry = r7;
   __ LoadP(entry,
            FieldMemOperand(array_pointer,
                            SharedFunctionInfo::kOffsetToPreviousCachedCode));
   __ LoadP(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.
   // Store code entry in the closure.
   __ addi(entry, entry, Operand(Code::kHeaderSize - kHeapObjectTag));
-
-  Label install_optimized_code_and_tailcall;
-  __ bind(&install_optimized_code_and_tailcall);
   __ StoreP(entry, FieldMemOperand(closure, JSFunction::kCodeEntryOffset), r0);
   __ RecordWriteCodeEntryField(closure, entry, r8);
 
   // Link the closure into the optimized function list.
   // r7 : code entry
   // r10: native context
   // r4 : closure
   __ LoadP(
       r8, ContextMemOperand(native_context, Context::OPTIMIZED_FUNCTIONS_LIST));
   __ StoreP(r8, FieldMemOperand(closure, JSFunction::kNextFunctionLinkOffset),
@@ skipping 14 matching lines @@
 
   __ bind(&loop_bottom);
   __ SubSmiLiteral(index, index, Smi::FromInt(SharedFunctionInfo::kEntryLength),
                    r0);
   __ CmpSmiLiteral(index, Smi::FromInt(1), r0);
   __ bgt(&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.
-  __ LoadP(entry,
-           FieldMemOperand(map, FixedArray::kHeaderSize +
-                                    SharedFunctionInfo::kSharedCodeIndex));
-  __ LoadP(entry, FieldMemOperand(entry, WeakCell::kValueOffset));
-  __ JumpIfSmi(entry, &try_shared);
-
-  // Store code entry in the closure.
-  __ addi(entry, entry, Operand(Code::kHeaderSize - kHeapObjectTag));
-  __ b(&install_optimized_code_and_tailcall);
-
   __ bind(&try_shared);
   // Is the full code valid?
   __ LoadP(entry,
            FieldMemOperand(closure, JSFunction::kSharedFunctionInfoOffset));
   __ LoadP(entry, FieldMemOperand(entry, SharedFunctionInfo::kCodeOffset));
   __ lwz(r8, FieldMemOperand(entry, Code::kFlagsOffset));
   __ DecodeField<Code::KindField>(r8);
   __ cmpi(r8, Operand(Code::BUILTIN));
   __ beq(&gotta_call_runtime);
   // Yes, install the full code.
@@ skipping 1484 matching lines @@
     __ CallRuntime(Runtime::kThrowStackOverflow);
     __ bkpt(0);
   }
 }
 
 #undef __
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_PPC