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dbms: improved performance of comparisons [#METR-2944].

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This commit is contained in:
Alexey Milovidov 2014-08-17 09:41:28 +04:00
parent aade03d427
commit bbd6064a19
1 changed files with 37 additions and 6 deletions
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43
dbms/include/DB/Functions/FunctionsComparison.h
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@ -50,23 +50,54 @@ struct NumComparisonImpl
{
static void vector_vector(const PODArray<A> & a, const PODArray<B> & b, PODArray<UInt8> & c)
{
/** GCC 4.8.2 векторизует цикл только если его записать в такой форме.
* В данном случае, если сделать цикл по индексу массива (код будет выглядеть проще),
* цикл не будет векторизовываться.
*/
size_t size = a.size();
for (size_t i = 0; i < size; ++i)
c[i] = Op::apply(a[i], b[i]);
const A * a_pos = &a[0];
const B * b_pos = &b[0];
UInt8 * c_pos = &c[0];
const A * a_end = a_pos + size;
while (a_pos < a_end)
{
*c_pos = Op::apply(*a_pos, *b_pos);
++a_pos;
++b_pos;
++c_pos;
}
}
static void vector_constant(const PODArray<A> & a, B b, PODArray<UInt8> & c)
{
size_t size = a.size();
for (size_t i = 0; i < size; ++i)
c[i] = Op::apply(a[i], b);
const A * a_pos = &a[0];
UInt8 * c_pos = &c[0];
const A * a_end = a_pos + size;
while (a_pos < a_end)
{
*c_pos = Op::apply(*a_pos, b);
++a_pos;
++c_pos;
}
}
static void constant_vector(A a, const PODArray<B> & b, PODArray<UInt8> & c)
{
size_t size = b.size();
for (size_t i = 0; i < size; ++i)
c[i] = Op::apply(a, b[i]);
const B * b_pos = &b[0];
UInt8 * c_pos = &c[0];
const B * b_end = b_pos + size;
while (b_pos < b_end)
{
*c_pos = Op::apply(a, *b_pos);
++b_pos;
++c_pos;
}
}
static void constant_constant(A a, B b, UInt8 & c)