Delete bundled copy of NSS and replace with README.

nspr/pr/include/prbit.h

-/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-#ifndef prbit_h___
-#define prbit_h___
-
-#include "prtypes.h"
-PR_BEGIN_EXTERN_C
-
-/*
-** Replace compare/jump/add/shift sequence with compiler built-in/intrinsic
-** functions.
-*/
-#if defined(_WIN32) && (_MSC_VER >= 1300) && \
-    (defined(_M_IX86) || defined(_M_AMD64) || defined(_M_ARM))
-# include <intrin.h>
-# pragma  intrinsic(_BitScanForward,_BitScanReverse)
-  __forceinline static int __prBitScanForward32(unsigned int val)
-  { 
-    unsigned long idx;
-    _BitScanForward(&idx, (unsigned long)val);
-    return( (int)idx );
-  }
-  __forceinline static int __prBitScanReverse32(unsigned int val)
-  {
-    unsigned long idx;
-    _BitScanReverse(&idx, (unsigned long)val);
-    return( (int)(31-idx) );
-  }
-# define pr_bitscan_ctz32(val)  __prBitScanForward32(val)
-# define pr_bitscan_clz32(val)  __prBitScanReverse32(val)
-# define  PR_HAVE_BUILTIN_BITSCAN32
-#elif ((__GNUC__ >= 4) || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)) && \
-       (defined(__i386__) || defined(__x86_64__) || defined(__arm__))
-# define pr_bitscan_ctz32(val)  __builtin_ctz(val)
-# define pr_bitscan_clz32(val)  __builtin_clz(val)
-# define  PR_HAVE_BUILTIN_BITSCAN32
-#endif /* MSVC || GCC */
-
-/*
-** A prbitmap_t is a long integer that can be used for bitmaps
-*/
-typedef unsigned long prbitmap_t;
-
-#define PR_TEST_BIT(_map,_bit) \
-    ((_map)[(_bit)>>PR_BITS_PER_LONG_LOG2] & (1L << ((_bit) & (PR_BITS_PER_LONG-1))))
-#define PR_SET_BIT(_map,_bit) \
-    ((_map)[(_bit)>>PR_BITS_PER_LONG_LOG2] |= (1L << ((_bit) & (PR_BITS_PER_LONG-1))))
-#define PR_CLEAR_BIT(_map,_bit) \
-    ((_map)[(_bit)>>PR_BITS_PER_LONG_LOG2] &= ~(1L << ((_bit) & (PR_BITS_PER_LONG-1))))
-
-/*
-** Compute the log of the least power of 2 greater than or equal to n
-*/
-NSPR_API(PRIntn) PR_CeilingLog2(PRUint32 i); 
-
-/*
-** Compute the log of the greatest power of 2 less than or equal to n
-*/
-NSPR_API(PRIntn) PR_FloorLog2(PRUint32 i); 
-
-/*
-** Macro version of PR_CeilingLog2: Compute the log of the least power of
-** 2 greater than or equal to _n. The result is returned in _log2.
-*/
-#ifdef PR_HAVE_BUILTIN_BITSCAN32 
-#define PR_CEILING_LOG2(_log2,_n)      \
-  PR_BEGIN_MACRO                       \
-    PRUint32 j_ = (PRUint32)(_n);      \
-    (_log2) = (j_ <= 1 ? 0 : 32 - pr_bitscan_clz32(j_ - 1)); \
-  PR_END_MACRO
-#else
-#define PR_CEILING_LOG2(_log2,_n)   \
-  PR_BEGIN_MACRO                    \
-    PRUint32 j_ = (PRUint32)(_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;               \
-  PR_END_MACRO
-#endif /* PR_HAVE_BUILTIN_BITSCAN32 */
-
-/*
-** Macro version of PR_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 PR_HAVE_BUILTIN_BITSCAN32
-#define PR_FLOOR_LOG2(_log2,_n)     \
-  PR_BEGIN_MACRO                    \
-    PRUint32 j_ = (PRUint32)(_n);   \
-    (_log2) = 31 - pr_bitscan_clz32((j_) | 1); \
-  PR_END_MACRO
-#else
-#define PR_FLOOR_LOG2(_log2,_n)   \
-  PR_BEGIN_MACRO                    \
-    PRUint32 j_ = (PRUint32)(_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;               \
-  PR_END_MACRO
-#endif /* PR_HAVE_BUILTIN_BITSCAN32 */
-
-/*
-** Macros for rotate left and right. The argument 'a' must be an unsigned
-** 32-bit integer type such as PRUint32.
-**
-** There is no rotate operation in the C Language, so the construct
-** (a << 4) | (a >> 28) is frequently used instead. Most compilers convert
-** this to a rotate instruction, but MSVC doesn't without a little help.
-** To get MSVC to generate a rotate instruction, we have to use the _rotl
-** or _rotr intrinsic and use a pragma to make it inline.
-**
-** Note: 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) || defined(_M_ARM))
-#include <stdlib.h>
-#pragma intrinsic(_rotl, _rotr)
-#define PR_ROTATE_LEFT32(a, bits) _rotl(a, bits)
-#define PR_ROTATE_RIGHT32(a, bits) _rotr(a, bits)
-#else
-#define PR_ROTATE_LEFT32(a, bits) (((a) << (bits)) | ((a) >> (32 - (bits))))
-#define PR_ROTATE_RIGHT32(a, bits) (((a) >> (bits)) | ((a) << (32 - (bits))))
-#endif
-
-PR_END_EXTERN_C
-#endif /* prbit_h___ */