MIPS[64]: Disable Add/Shl to Lsa optimization if operand is immediate

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 634 matching lines @@
 
 
 void InstructionSelector::VisitInt32Add(Node* node) {
   MipsOperandGenerator g(this);
   Int32BinopMatcher m(node);
 
   // Select Lsa for (left + (left_of_right << imm)).
   if (m.right().opcode() == IrOpcode::kWord32Shl &&
       CanCover(node, m.left().node()) && CanCover(node, m.right().node())) {
     Int32BinopMatcher mright(m.right().node());
-    if (mright.right().HasValue()) {
+    if (mright.right().HasValue() && !m.left().HasValue()) {
       int32_t shift_value = static_cast<int32_t>(mright.right().Value());
       Emit(kMipsLsa, g.DefineAsRegister(node), g.UseRegister(m.left().node()),
            g.UseRegister(mright.left().node()), g.TempImmediate(shift_value));
       return;
     }
   }
 
   // Select Lsa for ((left_of_left << imm) + right).
   if (m.left().opcode() == IrOpcode::kWord32Shl &&
       CanCover(node, m.right().node()) && CanCover(node, m.left().node())) {
     Int32BinopMatcher mleft(m.left().node());
-    if (mleft.right().HasValue()) {
+    if (mleft.right().HasValue() && !m.right().HasValue()) {
       int32_t shift_value = static_cast<int32_t>(mleft.right().Value());
       Emit(kMipsLsa, g.DefineAsRegister(node), g.UseRegister(m.right().node()),
            g.UseRegister(mleft.left().node()), g.TempImmediate(shift_value));
       return;
     }
   }
 
   VisitBinop(this, node, kMipsAdd, true, kMipsAdd);
 }
 
@@ skipping 1239 matching lines @@
     DCHECK(IsMipsArchVariant(kLoongson) || IsMipsArchVariant(kMips32r1) ||
            IsMipsArchVariant(kMips32r2));
     return MachineOperatorBuilder::AlignmentRequirements::
         NoUnalignedAccessSupport();
   }
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8