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Speed up sparse V3Number multiplication

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This commit is contained in:
Geza Lore 2021-05-02 04:51:41 +01:00
parent d77c9da983
commit 008b8d5b56
1 changed files with 6 additions and 2 deletions
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8
src/V3Number.cpp
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@ -1759,13 +1759,17 @@ V3Number& V3Number::opMul(const V3Number& lhs, const V3Number& rhs) {
opCleanThis(); // Mult produces extra bits in result
} else {
for (int lword = 0; lword < lhs.words(); lword++) {
const vluint64_t lwordval = static_cast<vluint64_t>(lhs.m_value[lword]);
if (lwordval == 0) continue;
for (int rword = 0; rword < rhs.words(); rword++) {
vluint64_t mul = static_cast<vluint64_t>(lhs.m_value[lword])
* static_cast<vluint64_t>(rhs.m_value[rword]);
const vluint64_t rwordval = static_cast<vluint64_t>(rhs.m_value[rword]);
if (rwordval == 0) continue;
vluint64_t mul = lwordval * rwordval;
for (int qword = lword + rword; qword < this->words(); qword++) {
mul += static_cast<vluint64_t>(m_value[qword]);
m_value[qword] = (mul & 0xffffffffULL);
mul = (mul >> 32ULL) & 0xffffffffULL;
if (mul == 0) break;
}
}
}