[turbofan]: Support using push instructions for setting up tail call parameters

src/compiler/x64/code-generator-x64.cc

Index: src/compiler/x64/code-generator-x64.cc
diff --git a/src/compiler/x64/code-generator-x64.cc b/src/compiler/x64/code-generator-x64.cc
index b42694c2cac642fbad717137530fdc379425c76b..c8bd884b2a7a5d49ed3d91b438567eb238295840 100644
--- a/src/compiler/x64/code-generator-x64.cc
+++ b/src/compiler/x64/code-generator-x64.cc
@@ -626,21 +626,7 @@ void CodeGenerator::AssembleDeconstructFrame() {
   __ popq(rbp);
 }
 
-void CodeGenerator::AssembleDeconstructActivationRecord(int stack_param_delta) {
-  int sp_slot_delta = TailCallFrameStackSlotDelta(stack_param_delta);
-  if (sp_slot_delta > 0) {
-    __ addq(rsp, Immediate(sp_slot_delta * kPointerSize));
-  }
-  frame_access_state()->SetFrameAccessToDefault();
-}
-
-
-void CodeGenerator::AssemblePrepareTailCall(int stack_param_delta) {
-  int sp_slot_delta = TailCallFrameStackSlotDelta(stack_param_delta);
-  if (sp_slot_delta < 0) {
-    __ subq(rsp, Immediate(-sp_slot_delta * kPointerSize));
-    frame_access_state()->IncreaseSPDelta(-sp_slot_delta);
-  }
+void CodeGenerator::AssemblePrepareTailCall() {
   if (frame_access_state()->has_frame()) {
     __ movq(rbp, MemOperand(rbp, 0));
   }
@@ -672,6 +658,73 @@ void CodeGenerator::AssemblePopArgumentsAdaptorFrame(Register args_reg,
   __ bind(&done);
 }
 
+namespace {
+void AdjustStackPointerForGap(MacroAssembler* masm, FrameAccessState* state,
+                              int new_slot_above_sp,
+                              bool allow_shrinkage = true) {
+  int current_sp_offset = state->GetSPToFPSlotCount() +
+                          StandardFrameConstants::kFixedSlotCountAboveFp;
+  int stack_slot_delta = new_slot_above_sp - current_sp_offset;
+  if (stack_slot_delta > 0) {
+    masm->subq(rsp, Immediate(stack_slot_delta * kPointerSize));
+    state->IncreaseSPDelta(stack_slot_delta);
+  } else if (allow_shrinkage && stack_slot_delta < 0) {
+    masm->addq(rsp, Immediate(-stack_slot_delta * kPointerSize));
+    state->IncreaseSPDelta(stack_slot_delta);
+  }
+}
+}  // namespace
+
+void CodeGenerator::AssemblePreGaps(Instruction* instr) {
+  int first_unused_stack_slot;
+  if (!GetSlotAboveSPAfterGap(instr, &first_unused_stack_slot)) return;
+
+  GapResolver::PushTypeFlags flags = GapResolver::kImmediatePush;

[Benedikt Meurer, 2016/06/30 07:57:06]

Nit: Merge these two lines.

[danno, 2016/07/01 07:31:56]

Done.

+  flags |= GapResolver::kScalarPush;
+  ZoneVector<MoveOperands*> pushes(zone());
+  resolver()->GetPushCompatibleMoves(zone(), instr, flags, &pushes);
+
+  if (pushes.size() > 0 &&

[Benedikt Meurer, 2016/06/30 07:57:06]

Nit: !pushes.empty()

[danno, 2016/07/01 07:31:56]

Done.

+      (LocationOperand::cast(pushes.back()->destination()).index() + 1 ==
+       first_unused_stack_slot)) {
+    X64OperandConverter g(this, instr);
+    for (auto move : pushes) {
+      LocationOperand destination_location(
+          LocationOperand::cast(move->destination()));
+      InstructionOperand source(move->source());
+      AdjustStackPointerForGap(masm(), frame_access_state(),
+                               destination_location.index());
+      if (source.IsStackSlot()) {
+        LocationOperand source_location(LocationOperand::cast(source));
+        __ Push(g.SlotToOperand(source_location.index()));
+        frame_access_state()->IncreaseSPDelta(1);
+        move->Eliminate();
+      } else if (source.IsRegister()) {
+        LocationOperand source_location(LocationOperand::cast(source));
+        __ Push(source_location.GetRegister());
+        frame_access_state()->IncreaseSPDelta(1);
+        move->Eliminate();
+      } else if (source.IsImmediate()) {
+        __ Push(Immediate(ImmediateOperand::cast(source).inline_value()));
+        frame_access_state()->IncreaseSPDelta(1);
+        move->Eliminate();
+      } else {
+        // Pushes of non-scalar data types is not supported.
+        UNIMPLEMENTED();
+      }
+    }
+  }
+  AdjustStackPointerForGap(masm(), frame_access_state(),
+                           first_unused_stack_slot, false);
+}
+
+void CodeGenerator::AssemblePostGaps(Instruction* instr) {
+  int first_unused_stack_slot;
+  if (!GetSlotAboveSPAfterGap(instr, &first_unused_stack_slot)) return;
+  AdjustStackPointerForGap(masm(), frame_access_state(),
+                           first_unused_stack_slot);
+}
+
 // Assembles an instruction after register allocation, producing machine code.
 CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     Instruction* instr) {
@@ -695,8 +748,6 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     }
     case kArchTailCallCodeObjectFromJSFunction:
     case kArchTailCallCodeObject: {
-      int stack_param_delta = i.InputInt32(instr->InputCount() - 1);
-      AssembleDeconstructActivationRecord(stack_param_delta);
       if (arch_opcode == kArchTailCallCodeObjectFromJSFunction) {
         AssemblePopArgumentsAdaptorFrame(kJavaScriptCallArgCountRegister,
                                          i.TempRegister(0), i.TempRegister(1),
@@ -711,15 +762,15 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
         __ jmp(reg);
       }
       frame_access_state()->ClearSPDelta();
+      frame_access_state()->SetFrameAccessToDefault();
       break;
     }
     case kArchTailCallAddress: {
-      int stack_param_delta = i.InputInt32(instr->InputCount() - 1);
-      AssembleDeconstructActivationRecord(stack_param_delta);
       CHECK(!HasImmediateInput(instr, 0));
       Register reg = i.InputRegister(0);
       __ jmp(reg);
       frame_access_state()->ClearSPDelta();
+      frame_access_state()->SetFrameAccessToDefault();
       break;
     }
     case kArchCallJSFunction: {
@@ -743,8 +794,6 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
         __ cmpp(rsi, FieldOperand(func, JSFunction::kContextOffset));
         __ Assert(equal, kWrongFunctionContext);
       }
-      int stack_param_delta = i.InputInt32(instr->InputCount() - 1);
-      AssembleDeconstructActivationRecord(stack_param_delta);
       if (arch_opcode == kArchTailCallJSFunctionFromJSFunction) {
         AssemblePopArgumentsAdaptorFrame(kJavaScriptCallArgCountRegister,
                                          i.TempRegister(0), i.TempRegister(1),
@@ -752,6 +801,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       }
       __ jmp(FieldOperand(func, JSFunction::kCodeEntryOffset));
       frame_access_state()->ClearSPDelta();
+      frame_access_state()->SetFrameAccessToDefault();
       break;
     }
     case kArchPrepareCallCFunction: {
@@ -762,7 +812,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kArchPrepareTailCall:
-      AssemblePrepareTailCall(i.InputInt32(instr->InputCount() - 1));
+      AssemblePrepareTailCall();
       break;
     case kArchCallCFunction: {
       int const num_parameters = MiscField::decode(instr->opcode());