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Diff for /OpenXM_contrib/gc/Attic/gc_hdrs.h between version 1.1.1.2 and 1.1.1.3

version 1.1.1.2, 2000/04/14 11:07:59 version 1.1.1.3, 2000/12/01 14:48:26
Line 24  typedef struct hblkhdr hdr;
Line 24  typedef struct hblkhdr hdr;
  * The 2 level tree data structure that is used to find block headers.   * The 2 level tree data structure that is used to find block headers.
  * If there are more than 32 bits in a pointer, the top level is a hash   * If there are more than 32 bits in a pointer, the top level is a hash
  * table.   * table.
    *
    * This defines HDR, GET_HDR, and SET_HDR, the main macros used to
    * retrieve and set object headers.  We also define some variants to
    * retrieve 2 unrelated headers in interleaved fashion.  This
    * slightly improves scheduling.
    *
    * Since 5.0 alpha 5, we can also take advantage of a header lookup
    * cache.  This is a locally declared direct mapped cache, used inside
    * the marker.  The HC_GET_HDR and HC_GET_HDR2 macros use and maintain this
    * cache.  Assuming we get reasonable hit rates, this shaves a few
    * memory references from each pointer validation.
  */   */
   
 # if CPP_WORDSZ > 32  # if CPP_WORDSZ > 32
Line 45  typedef struct hblkhdr hdr;
Line 56  typedef struct hblkhdr hdr;
 # define TOP_SZ (1 << LOG_TOP_SZ)  # define TOP_SZ (1 << LOG_TOP_SZ)
 # define BOTTOM_SZ (1 << LOG_BOTTOM_SZ)  # define BOTTOM_SZ (1 << LOG_BOTTOM_SZ)
   
   #ifndef SMALL_CONFIG
   # define USE_HDR_CACHE
   #endif
   
   /* #define COUNT_HDR_CACHE_HITS  */
   
   extern hdr * GC_invalid_header; /* header for an imaginary block        */
                                   /* containing no objects.               */
   
   
   /* Check whether p and corresponding hhdr point to long or invalid      */
   /* object.  If so, advance them to                                      */
   /* beginning of block, or set hhdr to GC_invalid_header.                */
   #define ADVANCE(p, hhdr, source) \
               if (IS_FORWARDING_ADDR_OR_NIL(hhdr)) { \
                 p = GC_FIND_START(p, hhdr, (word)source); \
                 if (p == 0) { \
                   hhdr = GC_invalid_header; \
                 } else { \
                   hhdr = GC_find_header(p); \
                 } \
               }
   
   #ifdef USE_HDR_CACHE
   
   # ifdef COUNT_HDR_CACHE_HITS
       extern word GC_hdr_cache_hits;
       extern word GC_hdr_cache_misses;
   #   define HC_HIT() ++GC_hdr_cache_hits
   #   define HC_MISS() ++GC_hdr_cache_misses
   # else
   #   define HC_HIT()
   #   define HC_MISS()
   # endif
   
     typedef struct hce {
       word block_addr;    /* right shifted by LOG_HBLKSIZE */
       hdr * hce_hdr;
     } hdr_cache_entry;
   
   # define HDR_CACHE_SIZE 8  /* power of 2 */
   
   # define DECLARE_HDR_CACHE \
           hdr_cache_entry hdr_cache[HDR_CACHE_SIZE]
   
   # define INIT_HDR_CACHE BZERO(hdr_cache, sizeof(hdr_cache));
   
   # define HCE(h) hdr_cache + (((word)(h) >> LOG_HBLKSIZE) & (HDR_CACHE_SIZE-1))
   
   # define HCE_VALID_FOR(hce,h) ((hce) -> block_addr == \
                                   ((word)(h) >> LOG_HBLKSIZE))
   
   # define HCE_HDR(h) ((hce) -> hce_hdr)
   
   
   /* Analogous to GET_HDR, except that in the case of large objects, it   */
   /* Returns the header for the object beginning, and updates p.          */
   /* Returns &GC_bad_header instead of 0.  All of this saves a branch     */
   /* in the fast path.                                                    */
   # define HC_GET_HDR(p, hhdr, source) \
           { \
             hdr_cache_entry * hce = HCE(p); \
             if (HCE_VALID_FOR(hce, p)) { \
               HC_HIT(); \
               hhdr = hce -> hce_hdr; \
             } else { \
               HC_MISS(); \
               GET_HDR(p, hhdr); \
               ADVANCE(p, hhdr, source); \
               hce -> block_addr = (word)(p) >> LOG_HBLKSIZE; \
               hce -> hce_hdr = hhdr; \
             } \
           }
   
   # define HC_GET_HDR2(p1, hhdr1, source1, p2, hhdr2, source2) \
           { \
             hdr_cache_entry * hce1 = HCE(p1); \
             hdr_cache_entry * hce2 = HCE(p2); \
             if (HCE_VALID_FOR(hce1, p1)) { \
               HC_HIT(); \
               hhdr1 = hce1 -> hce_hdr; \
             } else { \
               HC_MISS(); \
               GET_HDR(p1, hhdr1); \
               ADVANCE(p1, hhdr1, source1); \
               hce1 -> block_addr = (word)(p1) >> LOG_HBLKSIZE; \
               hce1 -> hce_hdr = hhdr1; \
             } \
             if (HCE_VALID_FOR(hce2, p2)) { \
               HC_HIT(); \
               hhdr2 = hce2 -> hce_hdr; \
             } else { \
               HC_MISS(); \
               GET_HDR(p2, hhdr2); \
               ADVANCE(p2, hhdr2, source2); \
               hce2 -> block_addr = (word)(p2) >> LOG_HBLKSIZE; \
               hce2 -> hce_hdr = hhdr2; \
             } \
           }
   
   #else /* !USE_HDR_CACHE */
   
   # define DECLARE_HDR_CACHE
   
   # define INIT_HDR_CACHE
   
   # define HC_GET_HDR(p, hhdr, source) \
           { \
             GET_HDR(p, hhdr); \
             ADVANCE(p, hhdr, source); \
           }
   
   # define HC_GET_HDR2(p1, hhdr1, source1, p2, hhdr2, source2) \
           { \
             GET_HDR2(p1, hhdr1, p2, hhdr2); \
             ADVANCE(p1, hhdr1, source1); \
             ADVANCE(p2, hhdr2, source2); \
           }
   
   #endif
   
 typedef struct bi {  typedef struct bi {
     hdr * index[BOTTOM_SZ];      hdr * index[BOTTOM_SZ];
         /*          /*
Line 97  typedef struct bi {
Line 229  typedef struct bi {
 #   define GET_HDR(p, hhdr) (hhdr) = HDR(p)  #   define GET_HDR(p, hhdr) (hhdr) = HDR(p)
 #   define SET_HDR(p, hhdr) HDR_INNER(p) = (hhdr)  #   define SET_HDR(p, hhdr) HDR_INNER(p) = (hhdr)
 #   define GET_HDR_ADDR(p, ha) (ha) = &(HDR_INNER(p))  #   define GET_HDR_ADDR(p, ha) (ha) = &(HDR_INNER(p))
   #   define GET_HDR2(p1, hhdr1, p2, hhdr2) \
           { GET_HDR(p1, hhdr1); GET_HDR(p2, hhdr2); }
 # else /* hash */  # else /* hash */
 /*  Hash function for tree top level */  /*  Hash function for tree top level */
 #   define TL_HASH(hi) ((hi) & (TOP_SZ - 1))  #   define TL_HASH(hi) ((hi) & (TOP_SZ - 1))
Line 123  typedef struct bi {
Line 257  typedef struct bi {
 #   define SET_HDR(p, hhdr) { register hdr ** _ha; GET_HDR_ADDR(p, _ha); \  #   define SET_HDR(p, hhdr) { register hdr ** _ha; GET_HDR_ADDR(p, _ha); \
                               *_ha = (hhdr); }                                *_ha = (hhdr); }
 #   define HDR(p) GC_find_header((ptr_t)(p))  #   define HDR(p) GC_find_header((ptr_t)(p))
       /* And some interleaved versions for two pointers at once.          */
       /* This hopefully helps scheduling on processors like IA64.         */
   #   define GET_BI2(p1, bottom_indx1, p2, bottom_indx2) \
           { \
               register word hi1 = \
                   (word)(p1) >> (LOG_BOTTOM_SZ + LOG_HBLKSIZE); \
               register word hi2 = \
                   (word)(p2) >> (LOG_BOTTOM_SZ + LOG_HBLKSIZE); \
               register bottom_index * _bi1 = GC_top_index[TL_HASH(hi1)]; \
               register bottom_index * _bi2 = GC_top_index[TL_HASH(hi2)]; \
               \
               while (_bi1 -> key != hi1 && _bi1 != GC_all_nils) \
                   _bi1 = _bi1 -> hash_link; \
               while (_bi2 -> key != hi2 && _bi2 != GC_all_nils) \
                   _bi2 = _bi2 -> hash_link; \
               (bottom_indx1) = _bi1; \
               (bottom_indx2) = _bi2; \
           }
   #   define GET_HDR_ADDR2(p1, ha1, p2, ha2) \
           { \
               register bottom_index * bi1; \
               register bottom_index * bi2; \
               \
               GET_BI2(p1, bi1, p2, bi2);  \
               (ha1) = &(HDR_FROM_BI(bi1, p1)); \
               (ha2) = &(HDR_FROM_BI(bi2, p2)); \
           }
   #   define GET_HDR2(p1, hhdr1, p2, hhdr2) \
           { register hdr ** _ha1;  \
             register hdr ** _ha2;  \
             GET_HDR_ADDR2(p1, _ha1, p2, _ha2); \
             (hhdr1) = *_ha1;  \
             (hhdr2) = *_ha2;  \
           }
 # endif  # endif
   
 /* Is the result a forwarding address to someplace closer to the        */  /* Is the result a forwarding address to someplace closer to the        */
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