[turbofan] MIPS64: Faster checked ops for PoT arrays

src/compiler/mips64/instruction-selector-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/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 1836 matching lines @@
   InstructionOperand offset_operand = g.CanBeImmediate(offset, opcode)
                                           ? g.UseImmediate(offset)
                                           : g.UseRegister(offset);
 
   InstructionOperand length_operand = (!g.CanBeImmediate(offset, opcode))
                                           ? g.CanBeImmediate(length, opcode)
                                                 ? g.UseImmediate(length)
                                                 : g.UseRegister(length)
                                           : g.UseRegister(length);
 
+  if (length->opcode() == IrOpcode::kInt32Constant) {
+    Int32Matcher m(length);
+    if (m.IsPowerOf2()) {
+      Emit(opcode, g.DefineAsRegister(node), offset_operand,
+           g.UseImmediate(length), g.UseRegister(buffer));
+      return;
+    }
+  }
+
   Emit(opcode | AddressingModeField::encode(kMode_MRI),
        g.DefineAsRegister(node), offset_operand, length_operand,
        g.UseRegister(buffer));
 }
 
 
 void InstructionSelector::VisitCheckedStore(Node* node) {
   MachineRepresentation rep = CheckedStoreRepresentationOf(node->op());
   Mips64OperandGenerator g(this);
   Node* const buffer = node->InputAt(0);
@@ skipping 32 matching lines @@
   InstructionOperand offset_operand = g.CanBeImmediate(offset, opcode)
                                           ? g.UseImmediate(offset)
                                           : g.UseRegister(offset);
 
   InstructionOperand length_operand = (!g.CanBeImmediate(offset, opcode))
                                           ? g.CanBeImmediate(length, opcode)
                                                 ? g.UseImmediate(length)
                                                 : g.UseRegister(length)
                                           : g.UseRegister(length);
 
+  if (length->opcode() == IrOpcode::kInt32Constant) {
+    Int32Matcher m(length);
+    if (m.IsPowerOf2()) {
+      Emit(opcode, g.NoOutput(), offset_operand, g.UseImmediate(length),
+           g.UseRegisterOrImmediateZero(value), g.UseRegister(buffer));
+      return;
+    }
+  }
+
   Emit(opcode | AddressingModeField::encode(kMode_MRI), g.NoOutput(),
        offset_operand, length_operand, g.UseRegisterOrImmediateZero(value),
        g.UseRegister(buffer));
 }
 
 
 namespace {
 
 // Shared routine for multiple compare operations.
 static void VisitCompare(InstructionSelector* selector, InstructionCode opcode,
@@ skipping 704 matching lines @@
   } else {
     DCHECK(kArchVariant == kMips64r2);
     return MachineOperatorBuilder::AlignmentRequirements::
         NoUnalignedAccessSupport();
   }
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8