# HG changeset patch # User dcoudert # Date 1376770316 -7200 # Sat Aug 17 22:11:56 2013 +0200 # Node ID b2d0906863b66f1e04a5d5bfb3b347c278b2f133 # Parent 707e593beb0b04aeba1b42108d62ede5cf16d16c trac #13352 -- Running time improvement of the bitset_len method diff --git a/module_list.py b/module_list.py --- a/module_list.py +++ b/module_list.py @@ -1220,6 +1220,12 @@ Extension('sage.misc.pickle_old', sources = ['sage/misc/pickle_old.pyx']), + Extension('sage.misc.popcount', + sources = ['sage/misc/popcount.pyx','sage/misc/popcount.cc'], + extra_compile_args = [], +# libraries = ["popcount"], + language = 'c++'), + Extension('sage.misc.randstate', sources = ['sage/misc/randstate.pyx'], libraries = ['gmp']), @@ -1236,9 +1242,9 @@ Extension('sage.misc.sage_timeit_class', sources = ['sage/misc/sage_timeit_class.pyx']), - - Extension('sage.misc.classcall_metaclass', - sources = ['sage/misc/classcall_metaclass.pyx']), + + Extension('sage.misc.classcall_metaclass', + sources = ['sage/misc/classcall_metaclass.pyx']), Extension('sage.misc.fast_methods', sources = ['sage/misc/fast_methods.pyx']), @@ -2082,19 +2088,19 @@ ) -if (os.path.isfile(SAGE_INC + "/cplex.h") and +if (os.path.isfile(SAGE_INC + "/cplex.h") and os.path.isfile(SAGE_LOCAL + "/lib/libcplex.a")): ext_modules.append( - Extension("sage.numerical.backends.cplex_backend", - ["sage/numerical/backends/cplex_backend.pyx"], - include_dirs = [SAGE_INC, "sage/c_lib/include/"], - language = 'c', - libraries = ["csage", "stdc++", "cplex"]) + Extension("sage.numerical.backends.cplex_backend", + ["sage/numerical/backends/cplex_backend.pyx"], + include_dirs = [SAGE_INC, "sage/c_lib/include/"], + language = 'c', + libraries = ["csage", "stdc++", "cplex"]) ) if is_package_installed('cbc'): ext_modules.append( - Extension("sage.numerical.backends.coin_backend", + Extension("sage.numerical.backends.coin_backend", ["sage/numerical/backends/coin_backend.pyx"], include_dirs = [SAGE_INC, "sage/c_lib/include/"], language = 'c++', diff --git a/sage/misc/bitset.pxd b/sage/misc/bitset.pxd --- a/sage/misc/bitset.pxd +++ b/sage/misc/bitset.pxd @@ -9,7 +9,7 @@ cpdef bint issubset(self, FrozenBitset other) cpdef bint issuperset(self, FrozenBitset other) cpdef bint isdisjoint(self, FrozenBitset other) - cpdef _union(self, FrozenBitset other) + cpdef _union(self, FrozenBitset other) cpdef intersection(self, FrozenBitset other) cpdef difference(self, FrozenBitset other) cpdef symmetric_difference(self, FrozenBitset other) diff --git a/sage/misc/bitset.pxi b/sage/misc/bitset.pxi --- a/sage/misc/bitset.pxi +++ b/sage/misc/bitset.pxi @@ -438,10 +438,10 @@ Calculate the number of items in the set (i.e., the number of nonzero bits). """ cdef long len = 0 - cdef long i = bitset_first(bits) - while i >= 0: - len += 1 - i = bitset_next(bits, i + 1) + cdef long i + for i from 0 <= i < bits.limbs: + if bits.bits[i]: + len += 1#popcountl(bits.bits[i]) return len cdef inline long bitset_hash(bitset_t bits): diff --git a/sage/misc/bitset_pxd.pxi b/sage/misc/bitset_pxd.pxi --- a/sage/misc/bitset_pxd.pxi +++ b/sage/misc/bitset_pxd.pxi @@ -16,6 +16,7 @@ # This is a .pxi file so that one can inline functions. Doctests in misc_c. include "sage/ext/stdsage.pxi" +#from sage.misc.popcount cimport popcount, popcountl cdef extern from *: void *memset(void *, int, size_t) diff --git a/sage/misc/popcount.cc b/sage/misc/popcount.cc new file mode 100644 --- /dev/null +++ b/sage/misc/popcount.cc @@ -0,0 +1,114 @@ +/* + Fast methods for counting bits. + + Implements some well known methods for counting the number of 1-bits in a 32 + and 64-bits integer. When available, it uses the __builtin_popcount or + __builtin_popcountl methods. Otherwise, it uses the MIT Hakmem 169 method. + See e.g. http://en.wikipedia.org/wiki/HAKMEM + + Usage: + 1) Add this into a .pxi of .pyx file + + cdef extern from "sage/misc/popcount.h": + unsigned int popcount(unsigned int) + unsigned int popcountl(unsigned long) + + 2) Then use popcount(i) for counting '1' bits in an unsigned int and + popcountl(l) for counting '1' bits in an unsigned long + +*/ + +//****************************************************************************** +// Copyright (C) 2013 David Coudert +// Nathann Cohen +// +// Distributed under the terms of the GNU General Public License (GPL) +// +// This code is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +// General Public License for more details. +// +// The full text of the GPL is available at: +// +// http://www.gnu.org/licenses/ +//****************************************************************************** + +#include +#include +//#ifdef __i386__ +#if (__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 8) +#define __USE_MULTIVERSIONNING 1 +#endif +//#endif + +// MIT HAKMEM 169 +int popcount32(uint32_t i){ + // Returns the number of '1' bits in a 32-bits integer. + i = i - ((i >> 1) & 0x55555555); + i = (i & 0x33333333) + ((i >> 2) & 0x33333333); + return( ((i + (i >> 4) & 0x0F0F0F0F) * 0x01010101) >> 24 ); +} + +int popcount64(uint64_t i){ + // Returns the number of '1' bits in a 64-bits integer. + i = i - ((i >> 1) & 0x5555555555555555ULL); + i = (i & 0x3333333333333333ULL) + ((i >> 2) & 0x3333333333333333ULL); + return( ( ((i + (i >> 4)) & 0x0f0f0f0f0f0f0f0fULL) * 0x0101010101010101ULL ) >> 56 ); +} + +/* + If GCC's version is >= 4.8 and arch is i386, we use multiversionning to use + the popcount instruction whenever available. + + See : + * http://gcc.gnu.org/wiki/FunctionMultiVersioning + * http://gcc.gnu.org/onlinedocs/gcc/Function-Multiversioning.html + */ +#ifdef __USE_MULTIVERSIONNING + +__attribute__ ((target ("default"))) +int popcountl(unsigned long i){ + printf("Good\n"); + return sizeof(long)==4? popcount32((uint32_t) i):popcount64((uint64_t) i); +} + +__attribute__ ((target ("default"))) +int popcount(unsigned int i){ + printf("Good\n"); + return sizeof(int)==4? popcount32((uint32_t) i):popcount64((uint64_t) i); +} + +__attribute__ ((target ("popcnt"))) +int popcount(unsigned int i){ + printf("Excellent\n"); + return __builtin_popcount(i); +} +__attribute__ ((target ("popcnt"))) +int popcountl(unsigned long i){ + printf("Excellent\n"); + return __builtin_popcountl(i); +} + +/* + * Tricks to decide at first loading time if __builtin_popcount is available. + * Otherwise, we use the MIT HAKMEM methods. + * + * This is based on a discussion initiated on a patch proposed by Cristian + * Rodriguez for lib/ext2fs/bitops.c. The discussion + * can be found at http://patchwork.ozlabs.org/patch/209776/ + * Further explanation can be found on the online doc of gcc + * http://gcc.gnu.org/onlinedocs/gcc/X86-Built_002din-Functions.html + */ +#else + +int popcount(unsigned int i){ + printf("Bad\n"); + return sizeof(int)==4? popcount32(i):popcount64(i); +} +int popcountl(unsigned long i){ + printf("Bad\n"); + return sizeof(long)==4? popcount32(i):popcount64(i); +} + +#endif diff --git a/sage/misc/popcount.hpp b/sage/misc/popcount.hpp new file mode 100644 --- /dev/null +++ b/sage/misc/popcount.hpp @@ -0,0 +1,4 @@ +int popcount32(uint32_t i); +int popcount64(uint64_t i); +int popcountl(unsigned long i); +int popcount(unsigned int i); diff --git a/sage/misc/popcount.pxd b/sage/misc/popcount.pxd new file mode 100644 --- /dev/null +++ b/sage/misc/popcount.pxd @@ -0,0 +1,4 @@ +cdef extern from *: + int popcountl(unsigned long) + int popcount(unsigned int) + diff --git a/sage/misc/popcount.pyx b/sage/misc/popcount.pyx new file mode 100644 --- /dev/null +++ b/sage/misc/popcount.pyx @@ -0,0 +1,6 @@ +r""" +This is an empty Cython wrapper for popcount functions from popcount.cc +""" +def test(n): + cdef int nn = n + print popcount(nn)