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

src/compiler/mips/code-generator-mips.cc

Index: src/compiler/mips/code-generator-mips.cc
diff --git a/src/compiler/mips/code-generator-mips.cc b/src/compiler/mips/code-generator-mips.cc
index 2b7ff10a5ca306de7bc988301c70e387dbe52858..62a60c39a3ec908e133dddd87611e744d6a7964f 100644
--- a/src/compiler/mips/code-generator-mips.cc
+++ b/src/compiler/mips/code-generator-mips.cc
@@ -448,19 +448,38 @@ FPUCondition FlagsConditionToConditionCmpFPU(bool& predicate,
 
 void CodeGenerator::AssembleDeconstructActivationRecord(int stack_param_delta) {
   CallDescriptor* descriptor = linkage()->GetIncomingDescriptor();
-  int stack_slots = frame()->GetSpillSlotCount();
-  int stack_pointer_delta = 0;
-  if (descriptor->IsJSFunctionCall() || stack_slots > 0) {
-    __ mov(sp, fp);
-    __ lw(fp, MemOperand(sp, 0 * kPointerSize));
-    __ lw(ra, MemOperand(sp, 1 * kPointerSize));
-    stack_pointer_delta = 2 * kPointerSize;
-  }
-  if (stack_param_delta < 0) {
-    stack_pointer_delta += -stack_param_delta * kPointerSize;
+  int spill_slots = frame()->GetSpillSlotCount();
+  bool has_frame = descriptor->IsJSFunctionCall() || spill_slots > 0;
+  if (has_frame) {
+    if (stack_param_delta != 0) {
+      int total_discarded_slots = frame()->GetTotalFrameSlotCount();
+      // Leave the PC and saved frame pointer on the stack.
+      total_discarded_slots -=
+          StandardFrameConstants::kFixedFrameSizeFromFp / kPointerSize;
+      // Discard only slots that won't be used by new parameters.
+      total_discarded_slots -= stack_param_delta;
+      if (total_discarded_slots > 0) {
+        __ addiu(sp, sp, total_discarded_slots * kPointerSize);
+      }
+    } else {
+      __ mov(sp, fp);
+    }
+    __ Pop(ra, fp);
   }
-  if (stack_pointer_delta != 0) {
-    __ addiu(sp, sp, stack_pointer_delta);
+}
+
+
+void CodeGenerator::AssemblePrepareTailCall(int stack_param_delta) {
+  if (stack_param_delta > 0) {
+    int total_discarded_slots = frame()->GetTotalFrameSlotCount();
+    // Leave the PC and saved frame pointer on the stack.
+    total_discarded_slots -=
+        StandardFrameConstants::kFixedFrameSizeFromFp / kPointerSize;
+    // Discard only slots that won't be used by new parameters.
+    total_discarded_slots -= stack_param_delta;
+    if (total_discarded_slots < 0) {
+      __ Subu(sp, sp, Operand(-total_discarded_slots * kPointerSize));
+    }
   }
 }
 
@@ -533,6 +552,9 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
       __ 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()) {