[turbofan][arm64] Match add with shifted operand for mult by a power of 2 plus 1.

src/compiler/arm64/instruction-selector-arm64.cc

Index: src/compiler/arm64/instruction-selector-arm64.cc
diff --git a/src/compiler/arm64/instruction-selector-arm64.cc b/src/compiler/arm64/instruction-selector-arm64.cc
index bf4427a2405ad0fcefdb1b467f35ed8559fddaed..baebb1700d1e23a8ccc7d338067f28554480c4a6 100644
--- a/src/compiler/arm64/instruction-selector-arm64.cc
+++ b/src/compiler/arm64/instruction-selector-arm64.cc
@@ -852,6 +852,18 @@ void InstructionSelector::VisitInt32Mul(Node* node) {
     }
   }
 
+  // x * (2^k + 1) -> x + (x << k)
+  if (m.right().HasValue() && m.right().Value() > 0) {
+    int32_t value = m.right().Value();
+    if (base::bits::IsPowerOfTwo32(value - 1)) {
+      Emit(kArm64Add32 | AddressingModeField::encode(kMode_Operand2_R_LSL_I),
+           g.DefineAsRegister(node), g.UseRegister(m.left().node()),
+           g.UseRegister(m.left().node()),
+           g.TempImmediate(WhichPowerOf2(value - 1)));
+      return;
+    }
+  }
+
   VisitRRR(this, kArm64Mul32, node);
 }
 
@@ -883,6 +895,18 @@ void InstructionSelector::VisitInt64Mul(Node* node) {
     }
   }
 
+  // x * (2^k + 1) -> x + (x << k)
+  if (m.right().HasValue() && m.right().Value() > 0) {
+    int64_t value = m.right().Value();
+    if (base::bits::IsPowerOfTwo64(value - 1)) {
+      Emit(kArm64Add | AddressingModeField::encode(kMode_Operand2_R_LSL_I),
+           g.DefineAsRegister(node), g.UseRegister(m.left().node()),
+           g.UseRegister(m.left().node()),
+           g.TempImmediate(WhichPowerOf2_64(value - 1)));
+      return;
+    }
+  }
+
   VisitRRR(this, kArm64Mul, node);
 }