PPC/s390: [builtins] Tweak optimized check in InterpreterEntryTrampoline

Port 7177d87f

Original Commit Message:

    Reorders the Smi check and the empty OptimizationMarker check as the
    latter implies the first and means there is now just a single comparison
    on the fast path.

R=delphick@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=
LOG=N

Change-Id: I4129e8d710d25fb1df02742816ab3b56430a7523
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1841611Reviewed-by: Junliang Yan <jyan@ca.ibm.com>
Commit-Queue: Junliang Yan <jyan@ca.ibm.com>
Cr-Commit-Position: refs/heads/master@{#64113}

src/builtins/ppc/builtins-ppc.cc

@@ -1079,24 +1079,17 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   __ cmpi(r7, Operand(FEEDBACK_VECTOR_TYPE));
   __ bne(&push_stack_frame);
 
-  Label has_optimization_marker;
-  Label maybe_has_optimized_code;
-
   Register optimized_code_entry = r7;
 
   // Read off the optimized code slot in the feedback vector.
   __ LoadP(optimized_code_entry,
            FieldMemOperand(feedback_vector,
                            FeedbackVector::kOptimizedCodeWeakOrSmiOffset));
-
-  // If not a Smi, then it must be a weak reference to the optimized code.
-  __ JumpIfNotSmi(optimized_code_entry, &maybe_has_optimized_code);
-
-  // Check if there is an optimization marker, if so carry onto the the
-  // MaybeOptimizeCode path.
+  // Check if the optimized code slot is not empty.
+  Label optimized_code_slot_not_empty;
   __ CmpSmiLiteral(optimized_code_entry,
                    Smi::FromEnum(OptimizationMarker::kNone), r0);
-  __ bne(&has_optimization_marker);
+  __ bne(&optimized_code_slot_not_empty);
 
   Label not_optimized;
   __ bind(&not_optimized);
@@ -1222,7 +1215,11 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   LeaveInterpreterFrame(masm, r5);
   __ blr();
 
-  __ bind(&has_optimization_marker);
+  __ bind(&optimized_code_slot_not_empty);
+  Label maybe_has_optimized_code;
+  // Check if optimized code marker is actually a weak reference to the
+  // optimized code.
+  __ JumpIfNotSmi(optimized_code_entry, &maybe_has_optimized_code);
   MaybeOptimizeCode(masm, feedback_vector, optimized_code_entry);
   // Fall through if there's no runnable optimized code.
   __ jmp(&not_optimized);

src/builtins/s390/builtins-s390.cc

@@ -1138,9 +1138,6 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   __ CmpP(r6, Operand(FEEDBACK_VECTOR_TYPE));
   __ bne(&push_stack_frame);
 
-  Label has_optimization_marker;
-  Label maybe_has_optimized_code;
-
   Register optimized_code_entry = r6;
 
   // Read off the optimized code slot in the feedback vector.
@@ -1148,14 +1145,11 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
            FieldMemOperand(feedback_vector,
                            FeedbackVector::kOptimizedCodeWeakOrSmiOffset));
 
-  // If not a Smi, then it must be a weak reference to the optimized code.
-  __ JumpIfNotSmi(optimized_code_entry, &maybe_has_optimized_code);
-
-  // Check if there is an optimization marker, if so carry onto the the
-  // MaybeOptimizeCode path.
+  // Check if the optimized code slot is not empty.
+  Label optimized_code_slot_not_empty;
   __ CmpSmiLiteral(optimized_code_entry,
                    Smi::FromEnum(OptimizationMarker::kNone), r0);
-  __ bne(&has_optimization_marker);
+  __ bne(&optimized_code_slot_not_empty);
 
   Label not_optimized;
   __ bind(&not_optimized);
@@ -1276,7 +1270,11 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   LeaveInterpreterFrame(masm, r4);
   __ Ret();
 
-  __ bind(&has_optimization_marker);
+  __ bind(&optimized_code_slot_not_empty);
+  Label maybe_has_optimized_code;
+  // Check if optimized code marker is actually a weak reference to the
+  // optimized code.
+  __ JumpIfNotSmi(optimized_code_entry, &maybe_has_optimized_code);
   MaybeOptimizeCode(masm, feedback_vector, optimized_code_entry);
   // Fall through if there's no runnable optimized code.
   __ jmp(&not_optimized);