/js/lib/Socket.IO-node/support/expresso/deps/jscoverage/js/jsbit.h
http://github.com/onedayitwillmake/RealtimeMultiplayerNodeJs · C++ Header · 253 lines · 128 code · 30 blank · 95 comment · 28 complexity · c5b629bee502bb97138841be652067b5 MD5 · raw file
- /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
- /* ***** BEGIN LICENSE BLOCK *****
- * Version: MPL 1.1/GPL 2.0/LGPL 2.1
- *
- * The contents of this file are subject to the Mozilla Public License Version
- * 1.1 (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.mozilla.org/MPL/
- *
- * Software distributed under the License is distributed on an "AS IS" basis,
- * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
- * for the specific language governing rights and limitations under the
- * License.
- *
- * The Original Code is Mozilla Communicator client code, released
- * March 31, 1998.
- *
- * The Initial Developer of the Original Code is
- * Netscape Communications Corporation.
- * Portions created by the Initial Developer are Copyright (C) 1998
- * the Initial Developer. All Rights Reserved.
- *
- * Contributor(s):
- *
- * Alternatively, the contents of this file may be used under the terms of
- * either of the GNU General Public License Version 2 or later (the "GPL"),
- * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
- * in which case the provisions of the GPL or the LGPL are applicable instead
- * of those above. If you wish to allow use of your version of this file only
- * under the terms of either the GPL or the LGPL, and not to allow others to
- * use your version of this file under the terms of the MPL, indicate your
- * decision by deleting the provisions above and replace them with the notice
- * and other provisions required by the GPL or the LGPL. If you do not delete
- * the provisions above, a recipient may use your version of this file under
- * the terms of any one of the MPL, the GPL or the LGPL.
- *
- * ***** END LICENSE BLOCK ***** */
- #ifndef jsbit_h___
- #define jsbit_h___
- #include "jstypes.h"
- #include "jsutil.h"
- JS_BEGIN_EXTERN_C
- /*
- ** A jsbitmap_t is a long integer that can be used for bitmaps
- */
- typedef JSUword jsbitmap_t; /* NSPR name, a la Unix system types */
- typedef jsbitmap_t jsbitmap; /* JS-style scalar typedef name */
- #define JS_BITMAP_SIZE(bits) (JS_HOWMANY(bits, JS_BITS_PER_WORD) * \
- sizeof(jsbitmap))
- #define JS_TEST_BIT(_map,_bit) ((_map)[(_bit)>>JS_BITS_PER_WORD_LOG2] & \
- ((jsbitmap)1<<((_bit)&(JS_BITS_PER_WORD-1))))
- #define JS_SET_BIT(_map,_bit) ((_map)[(_bit)>>JS_BITS_PER_WORD_LOG2] |= \
- ((jsbitmap)1<<((_bit)&(JS_BITS_PER_WORD-1))))
- #define JS_CLEAR_BIT(_map,_bit) ((_map)[(_bit)>>JS_BITS_PER_WORD_LOG2] &= \
- ~((jsbitmap)1<<((_bit)&(JS_BITS_PER_WORD-1))))
- /*
- ** Compute the log of the least power of 2 greater than or equal to n
- */
- extern JS_PUBLIC_API(JSIntn) JS_CeilingLog2(JSUint32 i);
- /*
- ** Compute the log of the greatest power of 2 less than or equal to n
- */
- extern JS_PUBLIC_API(JSIntn) JS_FloorLog2(JSUint32 i);
- /*
- * Replace bit-scanning code sequences with CPU-specific instructions to
- * speedup calculations of ceiling/floor log2.
- *
- * With GCC 3.4 or later we can use __builtin_clz for that, see bug 327129.
- *
- * SWS: Added MSVC intrinsic bitscan support. See bugs 349364 and 356856.
- */
- #if defined(_WIN32) && (_MSC_VER >= 1300) && defined(_M_IX86)
- unsigned char _BitScanForward(unsigned long * Index, unsigned long Mask);
- unsigned char _BitScanReverse(unsigned long * Index, unsigned long Mask);
- # pragma intrinsic(_BitScanForward,_BitScanReverse)
- __forceinline static int
- __BitScanForward32(unsigned int val)
- {
- unsigned long idx;
- _BitScanForward(&idx, (unsigned long)val);
- return (int)idx;
- }
- __forceinline static int
- __BitScanReverse32(unsigned int val)
- {
- unsigned long idx;
- _BitScanReverse(&idx, (unsigned long)val);
- return (int)(31-idx);
- }
- # define js_bitscan_ctz32(val) __BitScanForward32(val)
- # define js_bitscan_clz32(val) __BitScanReverse32(val)
- # define JS_HAS_BUILTIN_BITSCAN32
- #elif (__GNUC__ >= 4) || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
- # define js_bitscan_ctz32(val) __builtin_ctz(val)
- # define js_bitscan_clz32(val) __builtin_clz(val)
- # define JS_HAS_BUILTIN_BITSCAN32
- # if (JS_BYTES_PER_WORD == 8)
- # define js_bitscan_ctz64(val) __builtin_ctzll(val)
- # define js_bitscan_clz64(val) __builtin_clzll(val)
- # define JS_HAS_BUILTIN_BITSCAN64
- # endif
- #endif
- /*
- ** Macro version of JS_CeilingLog2: Compute the log of the least power of
- ** 2 greater than or equal to _n. The result is returned in _log2.
- */
- #ifdef JS_HAS_BUILTIN_BITSCAN32
- /*
- * Use intrinsic function or count-leading-zeros to calculate ceil(log2(_n)).
- * The macro checks for "n <= 1" and not "n != 0" as js_bitscan_clz32(0) is
- * undefined.
- */
- # define JS_CEILING_LOG2(_log2,_n) \
- JS_BEGIN_MACRO \
- JS_STATIC_ASSERT(sizeof(unsigned int) == sizeof(JSUint32)); \
- unsigned int j_ = (unsigned int)(_n); \
- (_log2) = (j_ <= 1 ? 0 : 32 - js_bitscan_clz32(j_ - 1)); \
- JS_END_MACRO
- #else
- # define JS_CEILING_LOG2(_log2,_n) \
- JS_BEGIN_MACRO \
- JSUint32 j_ = (JSUint32)(_n); \
- (_log2) = 0; \
- if ((j_) & ((j_)-1)) \
- (_log2) += 1; \
- if ((j_) >> 16) \
- (_log2) += 16, (j_) >>= 16; \
- if ((j_) >> 8) \
- (_log2) += 8, (j_) >>= 8; \
- if ((j_) >> 4) \
- (_log2) += 4, (j_) >>= 4; \
- if ((j_) >> 2) \
- (_log2) += 2, (j_) >>= 2; \
- if ((j_) >> 1) \
- (_log2) += 1; \
- JS_END_MACRO
- #endif
- /*
- ** Macro version of JS_FloorLog2: Compute the log of the greatest power of
- ** 2 less than or equal to _n. The result is returned in _log2.
- **
- ** This is equivalent to finding the highest set bit in the word.
- */
- #ifdef JS_HAS_BUILTIN_BITSCAN32
- /*
- * Use js_bitscan_clz32 or count-leading-zeros to calculate floor(log2(_n)).
- * Since js_bitscan_clz32(0) is undefined, the macro set the loweset bit to 1
- * to ensure 0 result when _n == 0.
- */
- # define JS_FLOOR_LOG2(_log2,_n) \
- JS_BEGIN_MACRO \
- JS_STATIC_ASSERT(sizeof(unsigned int) == sizeof(JSUint32)); \
- (_log2) = 31 - js_bitscan_clz32(((unsigned int)(_n)) | 1); \
- JS_END_MACRO
- #else
- # define JS_FLOOR_LOG2(_log2,_n) \
- JS_BEGIN_MACRO \
- JSUint32 j_ = (JSUint32)(_n); \
- (_log2) = 0; \
- if ((j_) >> 16) \
- (_log2) += 16, (j_) >>= 16; \
- if ((j_) >> 8) \
- (_log2) += 8, (j_) >>= 8; \
- if ((j_) >> 4) \
- (_log2) += 4, (j_) >>= 4; \
- if ((j_) >> 2) \
- (_log2) += 2, (j_) >>= 2; \
- if ((j_) >> 1) \
- (_log2) += 1; \
- JS_END_MACRO
- #endif
- /*
- * Internal function.
- * Compute the log of the least power of 2 greater than or equal to n.
- * This is a version of JS_CeilingLog2 that operates on jsuword with
- * CPU-dependant size.
- */
- #define JS_CEILING_LOG2W(n) ((n) <= 1 ? 0 : 1 + JS_FLOOR_LOG2W((n) - 1))
- /*
- * Internal function.
- * Compute the log of the greatest power of 2 less than or equal to n.
- * This is a version of JS_FloorLog2 that operates on jsuword with
- * CPU-dependant size and requires that n != 0.
- */
- #define JS_FLOOR_LOG2W(n) (JS_ASSERT((n) != 0), js_FloorLog2wImpl(n))
- #if JS_BYTES_PER_WORD == 4
- # ifdef JS_HAS_BUILTIN_BITSCAN32
- JS_STATIC_ASSERT(sizeof(unsigned) == sizeof(JSUword));
- # define js_FloorLog2wImpl(n) \
- ((JSUword)(JS_BITS_PER_WORD - 1 - js_bitscan_clz32(n)))
- # else
- # define js_FloorLog2wImpl(n) ((JSUword)JS_FloorLog2(n))
- #endif
- #elif JS_BYTES_PER_WORD == 8
- # ifdef JS_HAS_BUILTIN_BITSCAN64
- JS_STATIC_ASSERT(sizeof(unsigned long long) == sizeof(JSUword));
- # define js_FloorLog2wImpl(n) \
- ((JSUword)(JS_BITS_PER_WORD - 1 - js_bitscan_clz64(n)))
- # else
- extern JSUword js_FloorLog2wImpl(JSUword n);
- # endif
- #else
- # error "NOT SUPPORTED"
- #endif
- /*
- * Macros for rotate left. There is no rotate operation in the C Language so
- * the construct (a << 4) | (a >> 28) is used instead. Most compilers convert
- * this to a rotate instruction but some versions of MSVC don't without a
- * little help. To get MSVC to generate a rotate instruction, we have to use
- * the _rotl intrinsic and use a pragma to make _rotl inline.
- *
- * MSVC in VS2005 will do an inline rotate instruction on the above construct.
- */
- #if defined(_MSC_VER) && (defined(_M_IX86) || defined(_M_AMD64) || \
- defined(_M_X64))
- #include <stdlib.h>
- #pragma intrinsic(_rotl)
- #define JS_ROTATE_LEFT32(a, bits) _rotl(a, bits)
- #else
- #define JS_ROTATE_LEFT32(a, bits) (((a) << (bits)) | ((a) >> (32 - (bits))))
- #endif
- JS_END_EXTERN_C
- #endif /* jsbit_h___ */