Fixed power-of-2 predicates, excluding 0.

src/arm64/macro-assembler-arm64-inl.h

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1495 matching lines @@
     ASSERT(size % 16 == 0);
   } else {
     BumpSystemStackPointer(size);
   }
 
   Sub(StackPointer(), StackPointer(), size);
 }
 
 
 void MacroAssembler::Claim(const Register& count, uint64_t unit_size) {
+  if (unit_size == 0) return;
   ASSERT(IsPowerOf2(unit_size));
 
-  if (unit_size == 0) {
-    return;
-  }
-
   const int shift = CountTrailingZeros(unit_size, kXRegSizeInBits);
   const Operand size(count, LSL, shift);
 
   if (size.IsZero()) {
     return;
   }
 
   if (!csp.Is(StackPointer())) {
     BumpSystemStackPointer(size);
   }
@@ skipping 35 matching lines @@
   } else if (emit_debug_code()) {
     // It is safe to leave csp where it is when unwinding the JavaScript stack,
     // but if we keep it matching StackPointer, the simulator can detect memory
     // accesses in the now-free part of the stack.
     Mov(csp, StackPointer());
   }
 }
 
 
 void MacroAssembler::Drop(const Register& count, uint64_t unit_size) {
+  if (unit_size == 0) return;
   ASSERT(IsPowerOf2(unit_size));
 
-  if (unit_size == 0) {
-    return;
-  }
-
   const int shift = CountTrailingZeros(unit_size, kXRegSizeInBits);
   const Operand size(count, LSL, shift);
 
   if (size.IsZero()) {
     return;
   }
 
   Add(StackPointer(), StackPointer(), size);
 
   if (!csp.Is(StackPointer()) && emit_debug_code()) {
@@ skipping 99 matching lines @@
   // characters are reserved for controlling features of the instrumentation.
   ASSERT(isprint(marker_name[0]) && isprint(marker_name[1]));
 
   InstructionAccurateScope scope(this, 1);
   movn(xzr, (marker_name[1] << 8) | marker_name[0]);
 }
 
 } }  // namespace v8::internal
 
 #endif  // V8_ARM64_MACRO_ASSEMBLER_ARM64_INL_H_