lib/librte_table/rte_lru_x86.h

   1 /*-
   2  *   BSD LICENSE
   3  *
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  12  *       notice, this list of conditions and the following disclaimer.
  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 #include <rte_config.h>
  44
  45 #ifndef RTE_TABLE_HASH_LRU_STRATEGY
  46 #define RTE_TABLE_HASH_LRU_STRATEGY                        2
  47 #endif
  48
  49 #if RTE_TABLE_HASH_LRU_STRATEGY == 2
  50
  51 #if defined(RTE_TOOLCHAIN_GCC) && (GCC_VERSION > 40306)
  52 #include <x86intrin.h>
  53 #else
  54 #include <emmintrin.h>
  55 #include <smmintrin.h>
  56 #include <xmmintrin.h>
  57 #endif
  58
  59 #define lru_init(bucket)                                                \
  60         { bucket->lru_list = 0x0000000100020003LLU; }
  61
  62 #define lru_pos(bucket) (bucket->lru_list & 0xFFFFLLU)
  63
  64 #define lru_update(bucket, mru_val)                                     \
  65 do {                                                                    \
  66         /* set up the masks for all possible shuffles, depends on pos */\
  67         static uint64_t masks[10] = {                                   \
  68                 /* Shuffle order; Make Zero (see _mm_shuffle_epi8 manual) */\
  69                 0x0100070605040302, 0x8080808080808080,                 \
  70                 0x0302070605040100, 0x8080808080808080,                 \
  71                 0x0504070603020100, 0x8080808080808080,                 \
  72                 0x0706050403020100, 0x8080808080808080,                 \
  73                 0x0706050403020100, 0x8080808080808080};                \
  74         /* load up one register with repeats of mru-val  */             \
  75         uint64_t mru2 = mru_val;                                        \
  76         uint64_t mru3 = mru2 | (mru2 << 16);                            \
  77         uint64_t lru = bucket->lru_list;                                \
  78         /* XOR to cause the word we're looking for to go to zero */     \
  79         uint64_t mru = lru ^ ((mru3 << 32) | mru3);                     \
  80         __m128i c = _mm_cvtsi64_si128(mru);                             \
  81         __m128i b = _mm_cvtsi64_si128(lru);                             \
  82         /* Find the minimum value (first zero word, if it's in there) */\
  83         __m128i d = _mm_minpos_epu16(c);                                \
  84         /* Second word is the index to found word (first word is the value) */\
  85         unsigned int pos = _mm_extract_epi16(d, 1);                     \
  86         /* move the recently used location to top of list */            \
  87         __m128i k = _mm_shuffle_epi8(b, *((__m128i *) &masks[2 * pos]));\
  88         /* Finally, update the original list with the reordered data */ \
  89         bucket->lru_list = _mm_extract_epi64(k, 0);                     \
  90         /* Phwew! */                                                    \
  91 } while (0)
  92
  93 #elif RTE_TABLE_HASH_LRU_STRATEGY == 3
  94
  95 #if defined(RTE_TOOLCHAIN_GCC) && (GCC_VERSION > 40306)
  96 #include <x86intrin.h>
  97 #else
  98 #include <emmintrin.h>
  99 #include <smmintrin.h>
 100 #include <xmmintrin.h>
 101 #endif
 102
 103 #define lru_init(bucket)                                                \
 104         { bucket->lru_list = ~0LLU; }
 105
 106 static inline int
 107 f_lru_pos(uint64_t lru_list)
 108 {
 109         __m128i lst = _mm_set_epi64x((uint64_t)-1, lru_list);
 110         __m128i min = _mm_minpos_epu16(lst);
 111         return _mm_extract_epi16(min, 1);
 112 }
 113 #define lru_pos(bucket) f_lru_pos(bucket->lru_list)
 114
 115 #define lru_update(bucket, mru_val)                                     \
 116 do {                                                                    \
 117         const uint64_t orvals[] = {0xFFFFLLU, 0xFFFFLLU << 16,          \
 118                 0xFFFFLLU << 32, 0xFFFFLLU << 48, 0LLU};                \
 119         const uint64_t decs[] = {0x1000100010001LLU, 0};                \
 120         __m128i lru = _mm_cvtsi64_si128(bucket->lru_list);              \
 121         __m128i vdec = _mm_cvtsi64_si128(decs[mru_val>>2]);             \
 122         lru = _mm_subs_epu16(lru, vdec);                                \
 123         bucket->lru_list = _mm_extract_epi64(lru, 0) | orvals[mru_val]; \
 124 } while (0)
 125
 126 #endif
 127
 128 #ifdef __cplusplus
 129 }
 130 #endif
 131
 132 #endif