cp-algo/util/new_big.hpp

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• Last update: 2025-04-24 14:45:52+02:00
• Include: #include "cp-algo/util/new_big.hpp"
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Required by

• cp-algo/linalg/frobenius.hpp
• cp-algo/math/cvector.hpp
• cp-algo/math/fft.hpp
• cp-algo/math/poly.hpp
• cp-algo/math/poly/impl/div.hpp
• cp-algo/math/poly/impl/euclid.hpp

Verified with

• Characteristic Polynomial (verify/linalg/characteristic.test.cpp)
• Pow of Matrix (Frobenius) (verify/linalg/pow_fast.test.cpp)
• Bell Number (verify/poly/bell.test.cpp)
• Convolution mod $10^9+7$ (verify/poly/convolution107.test.cpp)
• Division of Polynomials (verify/poly/div.test.cpp)
• Exp of Power Series (verify/poly/exp.test.cpp)
• Find Linear Recurrence (verify/poly/find_linrec.test.cpp)
• Polynomial Interpolation (verify/poly/inter.test.cpp)
• Polynomial Interpolation (Geometric Sequence) (verify/poly/inter_geo.test.cpp)
• Inv of Power Series (verify/poly/inv.test.cpp)
• Inv of Polynomials (verify/poly/inv_mod.test.cpp)
• Consecutive Terms of Linear Recursion (verify/poly/linrec_consecutive.test.cpp)
• Kth term of Linearly Recurrent Sequence (verify/poly/linrec_single.test.cpp)
• Log of Power Series (verify/poly/log.test.cpp)
• Multipoint Evaluation (verify/poly/multieval.test.cpp)
• Multipoint Evaluation (Geometric Sequence) (verify/poly/multieval_geo.test.cpp)
• Pow of Power Series (verify/poly/pow.test.cpp)
• Product of Polynomial Sequence (verify/poly/prod_sequence.test.cpp)
• Polynomial Root Finding (verify/poly/roots.test.cpp)
• Shift of Sampling Points of Polynomial (verify/poly/sampling.test.cpp)
• Sqrt of Power Series (verify/poly/sqrt.test.cpp)
• Polynomial Taylor Shift (verify/poly/taylor.test.cpp)
• Wildcard Pattern Matching (verify/poly/wildcard.test.cpp)

Code

#ifndef CP_ALGO_UTIL_NEW_BIG_HPP
#define CP_ALGO_UTIL_NEW_BIG_HPP
#include <cstddef>

// Single macro to detect POSIX platforms (Linux, Unix, macOS)
#if defined(__linux__) || defined(__unix__) || (defined(__APPLE__) && defined(__MACH__))
#  define CP_ALGO_USE_MMAP 1
#  include <sys/mman.h>
#else
#  define CP_ALGO_USE_MMAP 0
#endif

namespace cp_algo {
    template<typename T>
    T* new_big(std::size_t len) {
#if CP_ALGO_USE_MMAP
        void* raw = mmap(nullptr, len * sizeof(T),
                         PROT_READ | PROT_WRITE,
                         MAP_PRIVATE | MAP_ANONYMOUS,
                         -1, 0);
        // Advise the kernel for huge pages and pre-populate writes
        madvise(raw, len * sizeof(T), MADV_HUGEPAGE);
        madvise(raw, len * sizeof(T), MADV_POPULATE_WRITE);
        return static_cast<T*>(raw);
#else
        // Fallback allocation for non-POSIX platforms
        return new T[len];
#endif
    }
    template<typename T>
    void delete_big(T* ptr, [[maybe_unused]] std::size_t len) {
#if CP_ALGO_USE_MMAP
        munmap(ptr, len * sizeof(T));
#else
        // Match allocation with delete[] on non-POSIX platforms
        delete[] ptr;
#endif
    }
}
#endif // CP_ALGO_UTIL_NEW_BIG_HPP

#line 1 "cp-algo/util/new_big.hpp"


#include <cstddef>

// Single macro to detect POSIX platforms (Linux, Unix, macOS)
#if defined(__linux__) || defined(__unix__) || (defined(__APPLE__) && defined(__MACH__))
#  define CP_ALGO_USE_MMAP 1
#  include <sys/mman.h>
#else
#  define CP_ALGO_USE_MMAP 0
#endif

namespace cp_algo {
    template<typename T>
    T* new_big(std::size_t len) {
#if CP_ALGO_USE_MMAP
        void* raw = mmap(nullptr, len * sizeof(T),
                         PROT_READ | PROT_WRITE,
                         MAP_PRIVATE | MAP_ANONYMOUS,
                         -1, 0);
        // Advise the kernel for huge pages and pre-populate writes
        madvise(raw, len * sizeof(T), MADV_HUGEPAGE);
        madvise(raw, len * sizeof(T), MADV_POPULATE_WRITE);
        return static_cast<T*>(raw);
#else
        // Fallback allocation for non-POSIX platforms
        return new T[len];
#endif
    }
    template<typename T>
    void delete_big(T* ptr, [[maybe_unused]] std::size_t len) {
#if CP_ALGO_USE_MMAP
        munmap(ptr, len * sizeof(T));
#else
        // Match allocation with delete[] on non-POSIX platforms
        delete[] ptr;
#endif
    }
}

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