[turbofan] Support variable size argument popping in TF-generated functions

src/compiler/mips64/code-generator-mips64.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/compilation-info.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 2263 matching lines @@
   }
 
   const RegList saves = descriptor->CalleeSavedRegisters();
   if (saves != 0) {
     // Save callee-saved registers.
     __ MultiPush(saves);
     DCHECK(kNumCalleeSaved == base::bits::CountPopulation32(saves) + 1);
   }
 }
 
-
-void CodeGenerator::AssembleReturn() {
+void CodeGenerator::AssembleReturn(InstructionOperand* pop) {
   CallDescriptor* descriptor = linkage()->GetIncomingDescriptor();
 
   // Restore GP registers.
   const RegList saves = descriptor->CalleeSavedRegisters();
   if (saves != 0) {
     __ MultiPop(saves);
   }
 
   // Restore FPU registers.
   const RegList saves_fpu = descriptor->CalleeSavedFPRegisters();
   if (saves_fpu != 0) {
     __ MultiPopFPU(saves_fpu);
   }
 
   if (descriptor->IsCFunctionCall()) {
     AssembleDeconstructFrame();
   } else if (frame_access_state()->has_frame()) {
     // Canonicalize JSFunction return sites for now.
     if (return_label_.is_bound()) {
       __ Branch(&return_label_);
       return;
     } else {
       __ bind(&return_label_);
       AssembleDeconstructFrame();
     }
   }
   int pop_count = static_cast<int>(descriptor->StackParameterCount());
+  Mips64OperandConverter g(this, nullptr);
+  if (pop->IsImmediate()) {
+    DCHECK_EQ(Constant::kInt32, g.ToConstant(pop).type());
+    pop_count += g.ToConstant(pop).ToInt32();
+  } else {
+    Register pop_reg = g.ToRegister(pop);
+    __ sll(pop_reg, pop_reg, Operand(kPointerSizeLog2));
+    __ addu(sp, sp, Operand(pop_reg));
+  }
   if (pop_count != 0) {
     __ DropAndRet(pop_count);
   } else {
     __ Ret();
   }
 }
 
 
 void CodeGenerator::AssembleMove(InstructionOperand* source,
                                  InstructionOperand* destination) {
@@ skipping 206 matching lines @@
       padding_size -= v8::internal::Assembler::kInstrSize;
     }
   }
 }
 
 #undef __
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8