First step to cleanup the power-of-2 mess.

src/x64/lithium-codegen-x64.cc

Index: src/x64/lithium-codegen-x64.cc
diff --git a/src/x64/lithium-codegen-x64.cc b/src/x64/lithium-codegen-x64.cc
index 74bb1327483111248f7381b6a1c35894ee6fd412..479c10127b67fd5876e4ec3dc3f2ff69025f293c 100644
--- a/src/x64/lithium-codegen-x64.cc
+++ b/src/x64/lithium-codegen-x64.cc
@@ -6,6 +6,7 @@
 
 #if V8_TARGET_ARCH_X64
 
+#include "src/base/bits.h"
 #include "src/code-stubs.h"
 #include "src/hydrogen-osr.h"
 #include "src/x64/lithium-codegen-x64.h"
@@ -1273,7 +1274,7 @@ void LCodeGen::DoDivByPowerOf2I(LDivByPowerOf2I* instr) {
   Register dividend = ToRegister(instr->dividend());
   int32_t divisor = instr->divisor();
   Register result = ToRegister(instr->result());
-  DCHECK(divisor == kMinInt || IsPowerOf2(Abs(divisor)));
+  DCHECK(divisor == kMinInt || base::bits::IsPowerOfTwo32(Abs(divisor)));
   DCHECK(!result.is(dividend));
 
   // Check for (0 / -x) that will produce negative zero.
@@ -5095,8 +5096,8 @@ void LCodeGen::DoCheckInstanceType(LCheckInstanceType* instr) {
     uint8_t tag;
     instr->hydrogen()->GetCheckMaskAndTag(&mask, &tag);
 
-    if (IsPowerOf2(mask)) {
-      DCHECK(tag == 0 || IsPowerOf2(tag));
+    if (base::bits::IsPowerOfTwo32(mask)) {
+      DCHECK(tag == 0 || base::bits::IsPowerOfTwo32(tag));
       __ testb(FieldOperand(kScratchRegister, Map::kInstanceTypeOffset),
                Immediate(mask));
       DeoptimizeIf(tag == 0 ? not_zero : zero, instr->environment());