diff options
Diffstat (limited to 'source/core')
| -rw-r--r-- | source/core/slang-uint-set.h | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/source/core/slang-uint-set.h b/source/core/slang-uint-set.h index 7e08500fd..077bc7981 100644 --- a/source/core/slang-uint-set.h +++ b/source/core/slang-uint-set.h @@ -19,8 +19,10 @@ constexpr Index intLog2(unsigned x) return x == 1 ? 0 : 1 + intLog2(x >> 1); } +// if `in` is 0, result is undefined behavior static inline Index bitscanForward(uint64_t in) { + SLANG_ASSERT(in != 0); #if defined(_MSC_VER) #ifdef _WIN64 @@ -28,14 +30,12 @@ static inline Index bitscanForward(uint64_t in) _BitScanForward64((unsigned long*)&out, in); return Index(out); #else - constexpr uint32_t bitsInType = sizeof(uint32_t) * 8; uint32_t out; // check for 0s in 0bit->31bit. If all 0's, check for 0s in 32bit->63bit - _BitScanForward((unsigned long*)&out, *(((uint32_t*)&in) + 1)); - if (out != bitsInType) + if (_BitScanForward((unsigned long*)&out, *(((uint32_t*)&in) + 1))) return Index(out); _BitScanForward((unsigned long*)&out, *(((uint32_t*)&in))); - return Index(out + bitsInType); + return Index(out); #endif// #ifdef _WIN64 #else |