1 // Copyright 2017 the V8 project authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef V8_REGLIST_H_ 6 #define V8_REGLIST_H_ 7 8 #include <cstdint> 9 10 #include "src/base/bits.h" 11 #include "src/base/template-utils.h" 12 13 namespace v8 { 14 namespace internal { 15 16 // Register configurations. 17 #if V8_TARGET_ARCH_ARM64 18 typedef uint64_t RegList; 19 #else 20 typedef uint32_t RegList; 21 #endif 22 23 // Get the number of registers in a given register list. 24 constexpr int NumRegs(RegList list) { 25 return base::bits::CountPopulation(list); 26 } 27 28 // Combine two RegLists by building the union of the contained registers. 29 // Implemented as a Functor to pass it to base::fold even on gcc < 5 (see 30 // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=52892). 31 // TODO(clemensh): Remove this once we require gcc >= 5.0. 32 struct CombineRegListsFunctor { 33 constexpr RegList operator()(RegList list1, RegList list2) const { 34 return list1 | list2; 35 } 36 }; 37 38 // Combine several RegLists by building the union of the contained registers. 39 template <typename... RegLists> 40 constexpr RegList CombineRegLists(RegLists... lists) { 41 return base::fold(CombineRegListsFunctor{}, 0, lists...); 42 } 43 44 } // namespace internal 45 } // namespace v8 46 47 #endif // V8_REGLIST_H_ 48
