bitcoin/src/compat/glibc_compat.cpp
fanquake 52f0be3a93
compat: remove memcpy -> memmove backwards compatibility alias
In glib 2.13 memcpy was changed such that the way it copied bytes was reversed.
This caused all sorts of issues for existing software, which depended on the
existing behavior (when they should have been using memmove). See:
https://sourceware.org/bugzilla/show_bug.cgi?id=12518
https://bugzilla.redhat.com/show_bug.cgi?id=638477

Now that we require glibc 2.17+ (#17538), we should be well clear of having to
maintain our memcpy ->  memmove aliasing, which was introduced in #4339.
2021-03-10 14:31:10 +08:00

62 lines
1.4 KiB
C++

// Copyright (c) 2009-2020 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#if defined(HAVE_CONFIG_H)
#include <config/bitcoin-config.h>
#endif
#include <cstddef>
#include <cstdint>
#if defined(__i386__) || defined(__arm__)
extern "C" int64_t __udivmoddi4(uint64_t u, uint64_t v, uint64_t* rp);
extern "C" int64_t __wrap___divmoddi4(int64_t u, int64_t v, int64_t* rp)
{
int32_t c1 = 0, c2 = 0;
int64_t uu = u, vv = v;
int64_t w;
int64_t r;
if (uu < 0) {
c1 = ~c1, c2 = ~c2, uu = -uu;
}
if (vv < 0) {
c1 = ~c1, vv = -vv;
}
w = __udivmoddi4(uu, vv, (uint64_t*)&r);
if (c1)
w = -w;
if (c2)
r = -r;
*rp = r;
return w;
}
#endif
extern "C" float log2f_old(float x);
#ifdef __i386__
__asm(".symver log2f_old,log2f@GLIBC_2.1");
#elif defined(__amd64__)
__asm(".symver log2f_old,log2f@GLIBC_2.2.5");
#elif defined(__arm__)
__asm(".symver log2f_old,log2f@GLIBC_2.4");
#elif defined(__aarch64__)
__asm(".symver log2f_old,log2f@GLIBC_2.17");
#elif defined(__powerpc64__)
# ifdef WORDS_BIGENDIAN
__asm(".symver log2f_old,log2f@GLIBC_2.3");
# else
__asm(".symver log2f_old,log2f@GLIBC_2.17");
# endif
#elif defined(__riscv)
__asm(".symver log2f_old,log2f@GLIBC_2.27");
#endif
extern "C" float __wrap_log2f(float x)
{
return log2f_old(x);
}