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xo-arena: DArenaHashMap: move detail::Group to dedicated file

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This commit is contained in:
Roland Conybeare 2026-01-08 18:34:31 -05:00
commit 7d85327928
2 changed files with 83 additions and 62 deletions
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63
xo-arena/include/xo/arena/DArenaHashMap.hpp
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@ -7,6 +7,7 @@
#include "DArenaVector.hpp"
#include "hashmap/DArenaHashMapUtil.hpp"
#include "hashmap/ControlGroup.hpp"
#include <xo/indentlog/scope.hpp>
#include <algorithm>
#include <array>
@ -62,68 +63,6 @@ namespace xo {
#endif
namespace detail {
/** @brief 16x 8-bit control bytes.
*
* Support optimization using SIMD operations
**/
struct Group {
std::array<uint8_t, DArenaHashMapUtil::c_group_size> ctrl_;
explicit Group(uint8_t * lo) {
::memcpy(ctrl_.data(), lo, DArenaHashMapUtil::c_group_size);
}
/** find all exact matches in ctrl_[0..15] for @p h2.
* for each match set corresponding bit in return value.
* Bits {0x1, 0x2, 0x4, ...} set iff exact match on
* {ctrl_[0], ctrl_[1], ctrl_2[], ...} respectively
**/
uint16_t all_matches(uint8_t h2) const {
uint16_t retval = 0;
uint16_t bit = 1;
for (auto xi : ctrl_) {
if (xi == h2)
retval |= bit;
bit = bit << 1;
}
return retval;
}
/** find all empty sentinels in ctrl_[0..15].
* for each empty, set corresponding bit in return value.
* Bits {0x1, 0x2, 0x4, ...} set iff empty spot
* {ctrl_[0], ctrl_[1], ctrl_[2], ...} respectively
**/
uint16_t empty_matches() const {
uint16_t retval = 0;
uint16_t bit = 1;
for (auto xi : ctrl_) {
if (xi == DArenaHashMapUtil::c_empty_slot)
retval |= bit;
bit = bit << 1;
}
return retval;
}
#ifdef NOT_YET
__m128i ctrl; // 16 bytes loaded via SSE2
// Find all slots matching h2
uint16_t Match(uint8_t h2) const {
__m128i pattern = _mm_set1_epi8(h2);
__m128i result = _mm_cmpeq_epi8(ctrl, pattern);
return _mm_movemask_epi8(result); // 16-bit mask
}
// Find all empty slots (0xFF)
uint16_t MatchEmpty() const {
return _mm_movemask_epi8(_mm_cmpeq_epi8(ctrl, _mm_set1_epi8(0xFF)));
}
#endif
};
template <typename Key,
typename Value>
struct HashMapStore : DArenaHashMapUtil {

82
xo-arena/include/xo/arena/hashmap/ControlGroup.hpp Normal file
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@ -0,0 +1,82 @@
/** @file ControlGroupo
*
* @author Roland Conybeare, Jan 2026
**/
#pragma once
#include "DArenaHashMapUtil.hpp"
#include <array>
#include <cstdint>
#include <cstring>
namespace xo {
namespace mm {
namespace detail {
/** @brief 16x 8-bit control bytes.
*
* Support optimization using SIMD operations
**/
struct Group {
std::array<uint8_t, DArenaHashMapUtil::c_group_size> ctrl_;
explicit Group(uint8_t * lo) {
::memcpy(ctrl_.data(), lo, DArenaHashMapUtil::c_group_size);
}
/** find all exact matches in ctrl_[0..15] for @p h2.
* for each match set corresponding bit in return value.
* Bits {0x1, 0x2, 0x4, ...} set iff exact match on
* {ctrl_[0], ctrl_[1], ctrl_2[], ...} respectively
**/
uint16_t all_matches(uint8_t h2) const {
uint16_t retval = 0;
uint16_t bit = 1;
for (auto xi : ctrl_) {
if (xi == h2)
retval |= bit;
bit = bit << 1;
}
return retval;
}
/** find all empty sentinels in ctrl_[0..15].
* for each empty, set corresponding bit in return value.
* Bits {0x1, 0x2, 0x4, ...} set iff empty spot
* {ctrl_[0], ctrl_[1], ctrl_[2], ...} respectively
**/
uint16_t empty_matches() const {
uint16_t retval = 0;
uint16_t bit = 1;
for (auto xi : ctrl_) {
if (xi == DArenaHashMapUtil::c_empty_slot)
retval |= bit;
bit = bit << 1;
}
return retval;
}
#ifdef NOT_YET
__m128i ctrl; // 16 bytes loaded via SSE2
// Find all slots matching h2
uint16_t Match(uint8_t h2) const {
__m128i pattern = _mm_set1_epi8(h2);
__m128i result = _mm_cmpeq_epi8(ctrl, pattern);
return _mm_movemask_epi8(result); // 16-bit mask
}
// Find all empty slots (0xFF)
uint16_t MatchEmpty() const {
return _mm_movemask_epi8(_mm_cmpeq_epi8(ctrl, _mm_set1_epi8(0xFF)));
}
#endif
};
}
} /*namespace mm*/
} /*namespace xo*/
/* end ControlGroup.hpp */