lib/librte_table/rte_lru_x86.h

   1 /*-
   2  *   BSD LICENSE
   3  *
   4  *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
   5  *   All rights reserved.
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   8  *   modification, are permitted provided that the following conditions
   9  *   are met:
  10  *
  11  *     * Redistributions of source code must retain the above copyright
  12  *       notice, this list of conditions and the following disclaimer.
  13  *     * Redistributions in binary form must reproduce the above copyright
  14  *       notice, this list of conditions and the following disclaimer in
  15  *       the documentation and/or other materials provided with the
  16  *       distribution.
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  18  *       contributors may be used to endorse or promote products derived
  19  *       from this software without specific prior written permission.
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  21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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  24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  25  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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  30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  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 #ifdef __INTEL_COMPILER
  44 #define GCC_VERSION (0)
  45 #else
  46 #define GCC_VERSION (__GNUC__ * 10000+__GNUC_MINOR__*100 + __GNUC_PATCHLEVEL__)
  47 #endif
  48
  49 #ifndef RTE_TABLE_HASH_LRU_STRATEGY
  50 #define RTE_TABLE_HASH_LRU_STRATEGY                        2
  51 #endif
  52
  53 #if RTE_TABLE_HASH_LRU_STRATEGY == 2
  54
  55 #if GCC_VERSION > 40306
  56 #include <x86intrin.h>
  57 #else
  58 #include <emmintrin.h>
  59 #include <smmintrin.h>
  60 #include <xmmintrin.h>
  61 #endif
  62
  63 #define lru_init(bucket)                                                \
  64         { bucket->lru_list = 0x0000000100020003LLU; }
  65
  66 #define lru_pos(bucket) (bucket->lru_list & 0xFFFFLLU)
  67
  68 #define lru_update(bucket, mru_val)                                     \
  69 do {                                                                    \
  70         /* set up the masks for all possible shuffles, depends on pos */\
  71         static uint64_t masks[10] = {                                   \
  72                 /* Shuffle order; Make Zero (see _mm_shuffle_epi8 manual) */\
  73                 0x0100070605040302, 0x8080808080808080,                 \
  74                 0x0302070605040100, 0x8080808080808080,                 \
  75                 0x0504070603020100, 0x8080808080808080,                 \
  76                 0x0706050403020100, 0x8080808080808080,                 \
  77                 0x0706050403020100, 0x8080808080808080};                \
  78         /* load up one register with repeats of mru-val  */             \
  79         uint64_t mru2 = mru_val;                                        \
  80         uint64_t mru3 = mru2 | (mru2 << 16);                            \
  81         uint64_t lru = bucket->lru_list;                                \
  82         /* XOR to cause the word we're looking for to go to zero */     \
  83         uint64_t mru = lru ^ ((mru3 << 32) | mru3);                     \
  84         __m128i c = _mm_cvtsi64_si128(mru);                             \
  85         __m128i b = _mm_cvtsi64_si128(lru);                             \
  86         /* Find the minimum value (first zero word, if it's in there) */\
  87         __m128i d = _mm_minpos_epu16(c);                                \
  88         /* Second word is the index to found word (first word is the value) */\
  89         unsigned int pos = _mm_extract_epi16(d, 1);                     \
  90         /* move the recently used location to top of list */            \
  91         __m128i k = _mm_shuffle_epi8(b, *((__m128i *) &masks[2 * pos]));\
  92         /* Finally, update the original list with the reordered data */ \
  93         bucket->lru_list = _mm_extract_epi64(k, 0);                     \
  94         /* Phwew! */                                                    \
  95 } while (0)
  96
  97 #elif RTE_TABLE_HASH_LRU_STRATEGY == 3
  98
  99 #if GCC_VERSION > 40306
 100 #include <x86intrin.h>
 101 #else
 102 #include <emmintrin.h>
 103 #include <smmintrin.h>
 104 #include <xmmintrin.h>
 105 #endif
 106
 107 #define lru_init(bucket)                                                \
 108         { bucket->lru_list = ~0LLU; }
 109
 110 static inline int
 111 f_lru_pos(uint64_t lru_list)
 112 {
 113         __m128i lst = _mm_set_epi64x((uint64_t)-1, lru_list);
 114         __m128i min = _mm_minpos_epu16(lst);
 115         return _mm_extract_epi16(min, 1);
 116 }
 117 #define lru_pos(bucket) f_lru_pos(bucket->lru_list)
 118
 119 #define lru_update(bucket, mru_val)                                     \
 120 do {                                                                    \
 121         const uint64_t orvals[] = {0xFFFFLLU, 0xFFFFLLU << 16,          \
 122                 0xFFFFLLU << 32, 0xFFFFLLU << 48, 0LLU};                \
 123         const uint64_t decs[] = {0x1000100010001LLU, 0};                \
 124         __m128i lru = _mm_cvtsi64_si128(bucket->lru_list);              \
 125         __m128i vdec = _mm_cvtsi64_si128(decs[mru_val>>2]);             \
 126         lru = _mm_subs_epu16(lru, vdec);                                \
 127         bucket->lru_list = _mm_extract_epi64(lru, 0) | orvals[mru_val]; \
 128 } while (0)
 129
 130 #endif
 131
 132 #ifdef __cplusplus
 133 }
 134 #endif
 135
 136 #endif