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Fix bug

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This commit is contained in:
Dmitrii Kovalkov 2020-05-15 14:06:12 +02:00
parent 43f5ca868a
commit d6d67b0da4
1 changed files with 4 additions and 3 deletions
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7
src/Functions/SIMDxorshift.cpp
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@ -55,11 +55,12 @@ void RandXorshiftImpl::execute(char * output, size_t size)
0xa321e1523f4f88c7ULL ^ reinterpret_cast<intptr_t>(output),
&mykey);
constexpr int safe_overwrite = 16; // How many bytes we can write behind the end.
constexpr int safe_overwrite = 15; // How many bytes we can write behind the end.
constexpr int bytes_per_write = 32;
constexpr intptr_t mask = bytes_per_write - 1;
if (size + safe_overwrite <= bytes_per_write) {
if (size + safe_overwrite < bytes_per_write) {
// size <= 16.
_mm_storeu_si128(reinterpret_cast<__m128i*>(output),
_mm256_extracti128_si256(avx_xorshift128plus(&mykey), 0));
return;
@ -74,7 +75,7 @@ void RandXorshiftImpl::execute(char * output, size_t size)
output += bytes_per_write;
}
// Process tail.
// Process tail. (end - output) <= 16.
if ((end - output) > 0) {
_mm_store_si128(reinterpret_cast<__m128i*>(output),
_mm256_extracti128_si256(avx_xorshift128plus(&mykey), 0));