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-rw-r--r--nsprpub/pr/include/prbit.h150
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diff --git a/nsprpub/pr/include/prbit.h b/nsprpub/pr/include/prbit.h
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+/* -*- 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___ */