[turbofan] Reland of `Add alignment parameter to StackSlot operator`

src/compiler/mips/instruction-selector-mips.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/base/adapters.h"
 #include "src/base/bits.h"
 #include "src/compiler/instruction-selector-impl.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/node-properties.h"
 
@@ skipping 238 matching lines @@
 static void VisitBinop(InstructionSelector* selector, Node* node,
                        InstructionCode opcode, FlagsContinuation* cont) {
   VisitBinop(selector, node, opcode, false, kArchNop, cont);
 }
 
 static void VisitBinop(InstructionSelector* selector, Node* node,
                        InstructionCode opcode) {
   VisitBinop(selector, node, opcode, false, kArchNop);
 }
 
+void InstructionSelector::VisitStackSlot(Node* node) {
+  StackSlotRepresentation rep = StackSlotRepresentationOf(node->op());
+  int alignment = rep.alignment();
+  int slot = frame_->AllocateSpillSlot(rep.size(), alignment);
+  OperandGenerator g(this);
+
+  Emit(kArchStackSlot, g.DefineAsRegister(node),
+       sequence()->AddImmediate(Constant(slot)),
+       sequence()->AddImmediate(Constant(alignment)), 0, nullptr);
+}
 
 void InstructionSelector::VisitLoad(Node* node) {
   LoadRepresentation load_rep = LoadRepresentationOf(node->op());
   MipsOperandGenerator g(this);
   Node* base = node->InputAt(0);
   Node* index = node->InputAt(1);
 
   ArchOpcode opcode = kArchNop;
   switch (load_rep.representation()) {
     case MachineRepresentation::kFloat32:
@@ skipping 1925 matching lines @@
     DCHECK(IsMipsArchVariant(kLoongson) || IsMipsArchVariant(kMips32r1) ||
            IsMipsArchVariant(kMips32r2));
     return MachineOperatorBuilder::AlignmentRequirements::
         NoUnalignedAccessSupport();
   }
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8