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mdbx-windows: fix nasty clz() (i.e. using _BitScanReverse() bug.

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Леонид Юрьев (Leonid Yuriev) 2022-09-21 14:32:18 +03:00
parent fe20de136c
commit beda291692
2 changed files with 15 additions and 3 deletions
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1
ChangeLog.md
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@ -11,6 +11,7 @@ New:
Fixes:
- Fixed an extra check for `MDBX_APPENDDUP` inside `mdbx_cursor_put()` which could result in returning `MDBX_EKEYMISMATCH` for valid cases.
- Fixed nasty `clz()` bug (by using `_BitScanReverse()`, only MSVC builds affected).
Minors:

17
src/core.c
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@ -5905,16 +5905,27 @@ MDBX_MAYBE_UNUSED static const pgno_t *scan4range_checker(const MDBX_PNL pnl,
#if defined(_MSC_VER) && !defined(__builtin_clz) && \
!__has_builtin(__builtin_clz)
MDBX_MAYBE_UNUSED static __always_inline size_t __builtin_clz(unsigned value) {
MDBX_MAYBE_UNUSED static __always_inline size_t __builtin_clz(uint32_t value) {
unsigned long index;
_BitScanReverse(&index, value);
return index;
return 31 - index;
}
#endif /* _MSC_VER */
#if defined(_MSC_VER) && !defined(__builtin_clzl) && \
!__has_builtin(__builtin_clzl)
#define __builtin_clzl(value) __builtin_clz(value)
MDBX_MAYBE_UNUSED static __always_inline size_t __builtin_clzl(size_t value) {
unsigned long index;
#ifdef _WIN64
assert(sizeof(value) == 8);
_BitScanReverse64(&index, value);
return 63 - index;
#else
assert(sizeof(value) == 4);
_BitScanReverse(&index, value);
return 31 - index;
#endif
}
#endif /* _MSC_VER */
#if !defined(MDBX_ATTRIBUTE_TARGET) && \