diff options
| author | 卜部昌平 <shyouhei@ruby-lang.org> | 2020-01-10 19:24:59 +0900 |
|---|---|---|
| committer | 卜部昌平 <shyouhei@ruby-lang.org> | 2020-01-10 21:17:15 +0900 |
| commit | 7fed7eb50b2b95ac4eeb3d29af3ce7b7d500032a (patch) | |
| tree | 72204697edb01f2f3866a99efeba690198d59f4b /internal | |
| parent | db0398dc04a5eb1e76955f6a80fcfe3041782371 (diff) | |
fix Windows breakage
Fixing typo revealed that _BitScanReverse is BSR, which behaves
differently than LZCNT. What we want here is LZCNT so we have to
emulate.
Notes
Notes:
Merged: https://github.com/ruby/ruby/pull/2824
Diffstat (limited to 'internal')
| -rw-r--r-- | internal/bits.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/internal/bits.h b/internal/bits.h index 802a8af7eb..9d4e71fc8f 100644 --- a/internal/bits.h +++ b/internal/bits.h @@ -215,7 +215,7 @@ nlz_int32(uint32_t x) #elif defined(_MSC_VER) && defined(_WIN64) /* &&! defined(__AVX2__) */ unsigned long r; - return _BitScanReverse(&r, x) ? (int)r : 32; + return _BitScanReverse(&r, x) ? (31 - (int)r) : 32; #elif __has_builtin(__builtin_clz) STATIC_ASSERT(sizeof_int, sizeof(int) * CHAR_BIT == 32); @@ -244,7 +244,7 @@ nlz_int64(uint64_t x) #elif defined(_MSC_VER) && defined(_WIN64) /* &&! defined(__AVX2__) */ unsigned long r; - return _BitScanReverse64(&r, x) ? (unsigned int)r : 64; + return _BitScanReverse64(&r, x) ? (63u - (unsigned int)r) : 64; #elif __has_builtin(__builtin_clzl) if (x == 0) { |