From: Christopher Dykes Date: Fri, 1 Apr 2016 18:19:53 +0000 (-0700) Subject: Create the Builtins portability header X-Git-Tag: 2016.07.26~380 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=98d33bb572ed225c13b104673ccbc149d7680fcf;p=folly.git Create the Builtins portability header Summary: Because we don't have these builtins under MSVC, and not having to deal with the differences in API in the places that use these builtins is good. Reviewed By: yfeldblum Differential Revision: D2984842 fb-gh-sync-id: 34db7455debf81e4abffe57c154eb731ae097ff6 fbshipit-source-id: 34db7455debf81e4abffe57c154eb731ae097ff6 --- diff --git a/folly/Makefile.am b/folly/Makefile.am index 96ff5665..9ac7c446 100644 --- a/folly/Makefile.am +++ b/folly/Makefile.am @@ -268,6 +268,7 @@ nobase_follyinclude_HEADERS = \ PicoSpinLock.h \ Portability.h \ portability/Asm.h \ + portability/Builtins.h \ portability/Config.h \ portability/Constexpr.h \ portability/Dirent.h \ diff --git a/folly/portability/Builtins.h b/folly/portability/Builtins.h new file mode 100755 index 00000000..959ce5c2 --- /dev/null +++ b/folly/portability/Builtins.h @@ -0,0 +1,59 @@ +/* + * Copyright 2016 Facebook, Inc. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#pragma once + +#ifdef _WIN32 +#include +#include +#include + +FOLLY_ALWAYS_INLINE int __builtin_clz(unsigned int x) { + unsigned long index; + return (int)(_BitScanReverse(&index, (unsigned long)x) ? 31 - index : 32); +} + +FOLLY_ALWAYS_INLINE int __builtin_clzl(unsigned long x) { + return __builtin_clz((unsigned int)x); +} + +FOLLY_ALWAYS_INLINE int __builtin_clzll(unsigned long long x) { + unsigned long index; + return (int)(_BitScanReverse64(&index, x) ? 63 - index : 64); +} + +FOLLY_ALWAYS_INLINE int __builtin_ffs(int x) { + unsigned long index; + return (int)(_BitScanForward(&index, (unsigned long)x) ? index : 0); +} + +FOLLY_ALWAYS_INLINE int __builtin_ffsl(long x) { return __builtin_ffs((int)x); } + +FOLLY_ALWAYS_INLINE int __builtin_ffsll(long long x) { + unsigned long index; + return (int)(_BitScanForward64(&index, (unsigned long long)x) ? index : 0); +} + +FOLLY_ALWAYS_INLINE int __builtin_popcountll(unsigned long long x) { + return (int)__popcnt64(x); +} + +FOLLY_ALWAYS_INLINE void* __builtin_return_address(unsigned int frame) { + // I really hope frame is zero... + assert(frame == 0); + return _ReturnAddress(); +} +#endif