[turbofan] Move platform-independent bits of VisitTailCall to instruction-selector.cc

src/compiler/instruction-selector.cc

Index: src/compiler/instruction-selector.cc
diff --git a/src/compiler/instruction-selector.cc b/src/compiler/instruction-selector.cc
index 92ac241127f39f26c13dbbe2b50c645cf401cc27..0569ab70844756d4e0a675cade887efabc2cc751 100644
--- a/src/compiler/instruction-selector.cc
+++ b/src/compiler/instruction-selector.cc
@@ -1072,6 +1072,79 @@ void InstructionSelector::VisitCall(Node* node, BasicBlock* handler) {
 }
 
 
+void InstructionSelector::VisitTailCall(Node* node) {
+  OperandGenerator g(this);
+  CallDescriptor const* descriptor = OpParameter<CallDescriptor const*>(node);
+  DCHECK_NE(0, descriptor->flags() & CallDescriptor::kSupportsTailCalls);
+  DCHECK_EQ(0, descriptor->flags() & CallDescriptor::kPatchableCallSite);
+  DCHECK_EQ(0, descriptor->flags() & CallDescriptor::kNeedsNopAfterCall);
+
+  // TODO(turbofan): Relax restriction for stack parameters.
+
+  if (linkage()->GetIncomingDescriptor()->CanTailCall(node)) {
+    CallBuffer buffer(zone(), descriptor, nullptr);
+
+    // Compute InstructionOperands for inputs and outputs.
+    InitializeCallBuffer(node, &buffer, true, true);
+
+    // Select the appropriate opcode based on the call type.
+    InstructionCode opcode;
+    switch (descriptor->kind()) {
+      case CallDescriptor::kCallCodeObject:
+        opcode = kArchTailCallCodeObject;
+        break;
+      case CallDescriptor::kCallJSFunction:
+        opcode = kArchTailCallJSFunction;
+        break;
+      default:
+        UNREACHABLE();
+        return;
+    }
+    opcode |= MiscField::encode(descriptor->flags());
+
+    // Emit the tailcall instruction.
+    Emit(opcode, 0, nullptr, buffer.instruction_args.size(),
+         &buffer.instruction_args.front());
+  } else {
+    FrameStateDescriptor* frame_state_descriptor =
+        descriptor->NeedsFrameState()
+            ? GetFrameStateDescriptor(
+                  node->InputAt(static_cast<int>(descriptor->InputCount())))
+            : nullptr;
+
+    CallBuffer buffer(zone(), descriptor, frame_state_descriptor);
+
+    // Compute InstructionOperands for inputs and outputs.
+    InitializeCallBuffer(node, &buffer, true, IsTailCallAddressImmediate());
+
+    EmitPrepareArguments(&(buffer.pushed_nodes), descriptor, node);
+
+    // Select the appropriate opcode based on the call type.
+    InstructionCode opcode;
+    switch (descriptor->kind()) {
+      case CallDescriptor::kCallCodeObject:
+        opcode = kArchCallCodeObject;
+        break;
+      case CallDescriptor::kCallJSFunction:
+        opcode = kArchCallJSFunction;
+        break;
+      default:
+        UNREACHABLE();
+        return;
+    }
+    opcode |= MiscField::encode(descriptor->flags());
+
+    // Emit the call instruction.
+    size_t output_count = buffer.outputs.size();
+    auto* outputs = &buffer.outputs.front();
+    Emit(opcode, output_count, outputs, buffer.instruction_args.size(),
+         &buffer.instruction_args.front())
+        ->MarkAsCall();
+    Emit(kArchRet, 0, nullptr, output_count, outputs);
+  }
+}
+
+
 void InstructionSelector::VisitGoto(BasicBlock* target) {
   // jump to the next block.
   OperandGenerator g(this);