PPC: [turbofan]: Implement tail calls with more callee than caller parameters

src/compiler/ppc/code-generator-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.
 
 #include "src/compiler/code-generator.h"
 
 #include "src/compiler/code-generator-impl.h"
 #include "src/compiler/gap-resolver.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/osr.h"
@@ skipping 588 matching lines @@
       __ asm_instr(value, operand);                           \
     } else {                                                  \
       __ asm_instrx(value, operand);                          \
     }                                                         \
     __ bind(&done);                                           \
     DCHECK_EQ(LeaveRC, i.OutputRCBit());                      \
   } while (0)
 
 
 void CodeGenerator::AssembleDeconstructActivationRecord(int stack_param_delta) {
+  int sp_slot_delta = TailCallFrameStackSlotDelta(stack_param_delta);
+  if (sp_slot_delta > 0) {
+    __ Add(sp, sp, sp_slot_delta * kPointerSize, r0);
+  }
   CallDescriptor* descriptor = linkage()->GetIncomingDescriptor();
-  int stack_slots = frame()->GetSpillSlotCount();
-  int sp_delta =
-      (stack_param_delta < 0) ? -stack_param_delta * kPointerSize : 0;
-  if (descriptor->IsJSFunctionCall() || stack_slots > 0) {
-    __ LeaveFrame(StackFrame::MANUAL, sp_delta);
-  } else if (sp_delta) {
-    __ Add(sp, sp, sp_delta, r0);
+  int spill_slots = frame()->GetSpillSlotCount();
+  bool has_frame = descriptor->IsJSFunctionCall() || spill_slots > 0;
+  if (has_frame) {
+    if (FLAG_enable_embedded_constant_pool) {
+      __ Pop(r0, fp, kConstantPoolRegister);
+    } else {
+      __ Pop(r0, fp);
+    }
+    __ mtlr(r0);
   }
 }
 
+
+void CodeGenerator::AssemblePrepareTailCall(int stack_param_delta) {
+  int sp_slot_delta = TailCallFrameStackSlotDelta(stack_param_delta);
+  if (sp_slot_delta < 0) {
+    __ Add(sp, sp, sp_slot_delta * kPointerSize, r0);
+  }
+}
+
 
 // Assembles an instruction after register allocation, producing machine code.
 void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
   PPCOperandConverter i(this, instr);
   ArchOpcode opcode = ArchOpcodeField::decode(instr->opcode());
 
   switch (opcode) {
     case kArchCallCodeObject: {
       v8::internal::Assembler::BlockTrampolinePoolScope block_trampoline_pool(
           masm());
@@ skipping 66 matching lines @@
           masm());
       EnsureSpaceForLazyDeopt();
       RecordCallPosition(instr);
       break;
     }
     case kArchPrepareCallCFunction: {
       int const num_parameters = MiscField::decode(instr->opcode());
       __ PrepareCallCFunction(num_parameters, kScratchReg);
       break;
     }
+    case kArchPrepareTailCall:
+      AssemblePrepareTailCall(i.InputInt32(instr->InputCount() - 1));
+      break;
     case kArchCallCFunction: {
       int const num_parameters = MiscField::decode(instr->opcode());
       if (instr->InputAt(0)->IsImmediate()) {
         ExternalReference ref = i.InputExternalReference(0);
         __ CallCFunction(ref, num_parameters);
       } else {
         Register func = i.InputRegister(0);
         __ CallCFunction(func, num_parameters);
       }
       break;
@@ skipping 1019 matching lines @@
       padding_size -= v8::internal::Assembler::kInstrSize;
     }
   }
 }
 
 #undef __
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8