lib/librte_table/rte_lru_x86.h

   1 /*-
   2  *   BSD LICENSE
   3  *
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  13  *     * Redistributions in binary form must reproduce the above copyright
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  15  *       the documentation and/or other materials provided with the
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  31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32  */
  33
  34 #ifndef __INCLUDE_RTE_LRU_X86_H__
  35 #define __INCLUDE_RTE_LRU_X86_H__
  36
  37 #ifdef __cplusplus
  38 extern "C" {
  39 #endif
  40
  41 #include <stdint.h>
  42
  43 #ifndef RTE_TABLE_HASH_LRU_STRATEGY
  44 #define RTE_TABLE_HASH_LRU_STRATEGY                        2
  45 #endif
  46
  47 #if RTE_TABLE_HASH_LRU_STRATEGY == 2
  48
  49 #if defined(RTE_TOOLCHAIN_GCC) && (GCC_VERSION > 40306)
  50 #include <x86intrin.h>
  51 #else
  52 #include <emmintrin.h>
  53 #include <smmintrin.h>
  54 #include <xmmintrin.h>
  55 #endif
  56
  57 #define lru_init(bucket)                                                \
  58         { bucket->lru_list = 0x0000000100020003LLU; }
  59
  60 #define lru_pos(bucket) (bucket->lru_list & 0xFFFFLLU)
  61
  62 #define lru_update(bucket, mru_val)                                     \
  63 do {                                                                    \
  64         /* set up the masks for all possible shuffles, depends on pos */\
  65         static uint64_t masks[10] = {                                   \
  66                 /* Shuffle order; Make Zero (see _mm_shuffle_epi8 manual) */\
  67                 0x0100070605040302, 0x8080808080808080,                 \
  68                 0x0302070605040100, 0x8080808080808080,                 \
  69                 0x0504070603020100, 0x8080808080808080,                 \
  70                 0x0706050403020100, 0x8080808080808080,                 \
  71                 0x0706050403020100, 0x8080808080808080};                \
  72         /* load up one register with repeats of mru-val  */             \
  73         uint64_t mru2 = mru_val;                                        \
  74         uint64_t mru3 = mru2 | (mru2 << 16);                            \
  75         uint64_t lru = bucket->lru_list;                                \
  76         /* XOR to cause the word we're looking for to go to zero */     \
  77         uint64_t mru = lru ^ ((mru3 << 32) | mru3);                     \
  78         __m128i c = _mm_cvtsi64_si128(mru);                             \
  79         __m128i b = _mm_cvtsi64_si128(lru);                             \
  80         /* Find the minimum value (first zero word, if it's in there) */\
  81         __m128i d = _mm_minpos_epu16(c);                                \
  82         /* Second word is the index to found word (first word is the value) */\
  83         unsigned int pos = _mm_extract_epi16(d, 1);                     \
  84         /* move the recently used location to top of list */            \
  85         __m128i k = _mm_shuffle_epi8(b, *((__m128i *) &masks[2 * pos]));\
  86         /* Finally, update the original list with the reordered data */ \
  87         bucket->lru_list = _mm_extract_epi64(k, 0);                     \
  88         /* Phwew! */                                                    \
  89 } while (0)
  90
  91 #elif RTE_TABLE_HASH_LRU_STRATEGY == 3
  92
  93 #if defined(RTE_TOOLCHAIN_GCC) && (GCC_VERSION > 40306)
  94 #include <x86intrin.h>
  95 #else
  96 #include <emmintrin.h>
  97 #include <smmintrin.h>
  98 #include <xmmintrin.h>
  99 #endif
 100
 101 #define lru_init(bucket)                                                \
 102         { bucket->lru_list = ~0LLU; }
 103
 104 static inline int
 105 f_lru_pos(uint64_t lru_list)
 106 {
 107         __m128i lst = _mm_set_epi64x((uint64_t)-1, lru_list);
 108         __m128i min = _mm_minpos_epu16(lst);
 109         return _mm_extract_epi16(min, 1);
 110 }
 111 #define lru_pos(bucket) f_lru_pos(bucket->lru_list)
 112
 113 #define lru_update(bucket, mru_val)                                     \
 114 do {                                                                    \
 115         const uint64_t orvals[] = {0xFFFFLLU, 0xFFFFLLU << 16,          \
 116                 0xFFFFLLU << 32, 0xFFFFLLU << 48, 0LLU};                \
 117         const uint64_t decs[] = {0x1000100010001LLU, 0};                \
 118         __m128i lru = _mm_cvtsi64_si128(bucket->lru_list);              \
 119         __m128i vdec = _mm_cvtsi64_si128(decs[mru_val>>2]);             \
 120         lru = _mm_subs_epu16(lru, vdec);                                \
 121         bucket->lru_list = _mm_extract_epi64(lru, 0) | orvals[mru_val]; \
 122 } while (0)
 123
 124 #endif
 125
 126 #ifdef __cplusplus
 127 }
 128 #endif
 129
 130 #endif