[turbofan][cleanup] Add helper function for effect level

I noticed a pattern that has been copied around to various places and
thought a helper function might be appropriate.

Change-Id: I8944ac5166c649f15c09f587308406cab317b8d4
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2346766Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#69344}

src/compiler/backend/ia32/instruction-selector-ia32.cc

@@ -598,11 +598,7 @@ void VisitBinop(InstructionSelector* selector, Node* node,
     inputs[input_count++] = g.UseRegister(left);
     inputs[input_count++] = g.UseImmediate(right);
   } else {
-    int effect_level = selector->GetEffectLevel(node);
-    if (cont->IsBranch()) {
-      effect_level = selector->GetEffectLevel(
-          cont->true_block()->PredecessorAt(0)->control_input());
-    }
+    int effect_level = selector->GetEffectLevel(node, cont);
     if (node->op()->HasProperty(Operator::kCommutative) &&
         g.CanBeBetterLeftOperand(right) &&
         (!g.CanBeBetterLeftOperand(left) ||
@@ -664,11 +660,7 @@ void InstructionSelector::VisitStackPointerGreaterThan(
   InstructionCode opcode =
       kArchStackPointerGreaterThan | MiscField::encode(static_cast<int>(kind));
 
-  int effect_level = GetEffectLevel(node);
-  if (cont->IsBranch()) {
-    effect_level =
-        GetEffectLevel(cont->true_block()->PredecessorAt(0)->control_input());
-  }
+  int effect_level = GetEffectLevel(node, cont);
 
   IA32OperandGenerator g(this);
 
@@ -1442,11 +1434,7 @@ void VisitWordCompare(InstructionSelector* selector, Node* node,
   InstructionCode narrowed_opcode =
       TryNarrowOpcodeSize(opcode, left, right, cont);
 
-  int effect_level = selector->GetEffectLevel(node);
-  if (cont->IsBranch()) {
-    effect_level = selector->GetEffectLevel(
-        cont->true_block()->PredecessorAt(0)->control_input());
-  }
+  int effect_level = selector->GetEffectLevel(node, cont);
 
   // If one of the two inputs is an immediate, make sure it's on the right, or
   // if one of the two inputs is a memory operand, make sure it's on the left.

src/compiler/backend/instruction-selector.cc

@@ -422,6 +422,14 @@ int InstructionSelector::GetEffectLevel(Node* node) const {
   return effect_level_[id];
 }
 
+int InstructionSelector::GetEffectLevel(Node* node,
+                                        FlagsContinuation* cont) const {
+  return cont->IsBranch()
+             ? GetEffectLevel(
+                   cont->true_block()->PredecessorAt(0)->control_input())
+             : GetEffectLevel(node);
+}
+
 void InstructionSelector::SetEffectLevel(Node* node, int effect_level) {
   DCHECK_NOT_NULL(node);
   size_t const id = node->id();

src/compiler/backend/instruction-selector.h

@@ -440,6 +440,10 @@ class V8_EXPORT_PRIVATE InstructionSelector final {
   // Gets the effect level of {node}.
   int GetEffectLevel(Node* node) const;
 
+  // Gets the effect level of {node}, appropriately adjusted based on
+  // continuation flags if the node is a branch.
+  int GetEffectLevel(Node* node, FlagsContinuation* cont) const;
+
   int GetVirtualRegister(const Node* node);
   const std::map<NodeId, int> GetVirtualRegistersForTesting() const;
 

src/compiler/backend/s390/instruction-selector-s390.cc

@@ -1713,11 +1713,7 @@ void VisitWordCompare(InstructionSelector* selector, Node* node,
 
   // If one of the two inputs is an immediate, make sure it's on the right, or
   // if one of the two inputs is a memory operand, make sure it's on the left.
-  int effect_level = selector->GetEffectLevel(node);
-  if (cont->IsBranch()) {
-    effect_level = selector->GetEffectLevel(
-        cont->true_block()->PredecessorAt(0)->control_input());
-  }
+  int effect_level = selector->GetEffectLevel(node, cont);
 
   if ((!g.CanBeImmediate(right, immediate_mode) &&
        g.CanBeImmediate(left, immediate_mode)) ||
@@ -1815,11 +1811,7 @@ void VisitLoadAndTest(InstructionSelector* selector, InstructionCode opcode,
   size_t output_count = 0;
   bool use_value = false;
 
-  int effect_level = selector->GetEffectLevel(node);
-  if (cont->IsBranch()) {
-    effect_level = selector->GetEffectLevel(
-        cont->true_block()->PredecessorAt(0)->control_input());
-  }
+  int effect_level = selector->GetEffectLevel(node, cont);
 
   if (g.CanBeMemoryOperand(opcode, node, value, effect_level)) {
     // generate memory operand

src/compiler/backend/x64/instruction-selector-x64.cc

@@ -514,11 +514,7 @@ static void VisitBinop(InstructionSelector* selector, Node* node,
     inputs[input_count++] = g.UseRegister(left);
     inputs[input_count++] = g.UseImmediate(right);
   } else {
-    int effect_level = selector->GetEffectLevel(node);
-    if (cont->IsBranch()) {
-      effect_level = selector->GetEffectLevel(
-          cont->true_block()->PredecessorAt(0)->control_input());
-    }
+    int effect_level = selector->GetEffectLevel(node, cont);
     if (node->op()->HasProperty(Operator::kCommutative) &&
         g.CanBeBetterLeftOperand(right) &&
         (!g.CanBeBetterLeftOperand(left) ||
@@ -609,11 +605,7 @@ void InstructionSelector::VisitStackPointerGreaterThan(
   InstructionCode opcode =
       kArchStackPointerGreaterThan | MiscField::encode(static_cast<int>(kind));
 
-  int effect_level = GetEffectLevel(node);
-  if (cont->IsBranch()) {
-    effect_level =
-        GetEffectLevel(cont->true_block()->PredecessorAt(0)->control_input());
-  }
+  int effect_level = GetEffectLevel(node, cont);
 
   X64OperandGenerator g(this);
   Node* const value = node->InputAt(0);
@@ -1864,11 +1856,7 @@ void VisitWordCompare(InstructionSelector* selector, Node* node,
 
   // If one of the two inputs is an immediate, make sure it's on the right, or
   // if one of the two inputs is a memory operand, make sure it's on the left.
-  int effect_level = selector->GetEffectLevel(node);
-  if (cont->IsBranch()) {
-    effect_level = selector->GetEffectLevel(
-        cont->true_block()->PredecessorAt(0)->control_input());
-  }
+  int effect_level = selector->GetEffectLevel(node, cont);
 
   if ((!g.CanBeImmediate(right) && g.CanBeImmediate(left)) ||
       (g.CanBeMemoryOperand(opcode, node, right, effect_level) &&
@@ -2005,11 +1993,7 @@ void VisitCompareZero(InstructionSelector* selector, Node* user, Node* node,
         break;
     }
   }
-  int effect_level = selector->GetEffectLevel(node);
-  if (cont->IsBranch()) {
-    effect_level = selector->GetEffectLevel(
-        cont->true_block()->PredecessorAt(0)->control_input());
-  }
+  int effect_level = selector->GetEffectLevel(node, cont);
   if (node->opcode() == IrOpcode::kLoad) {
     switch (LoadRepresentationOf(node->op()).representation()) {
       case MachineRepresentation::kWord8: