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Diff for /OpenXM_contrib2/asir2000/gc/include/private/gc_hdrs.h between version 1.1 and 1.4

version 1.1, 1999/12/03 07:39:10 version 1.4, 2002/07/24 08:00:20
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.
    *
    * 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 macro uses and maintains 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 44  typedef struct hblkhdr hdr;
Line 53  typedef struct hblkhdr hdr;
 # endif  # endif
 # 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 hhdr to                                      */
   /* beginning of block, or set hhdr to GC_invalid_header.                */
   #define ADVANCE(p, hhdr, source) \
               { \
                 hdr * new_hdr = GC_invalid_header; \
                 p = GC_find_start(p, hhdr, &new_hdr); \
                 hhdr = new_hdr; \
               }
   
   #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); \
               if (IS_FORWARDING_ADDR_OR_NIL(hhdr)) { \
                 ADVANCE(p, hhdr, source); \
               } else { \
                 hce -> block_addr = (word)(p) >> LOG_HBLKSIZE; \
                 hce -> hce_hdr = hhdr; \
               } \
             } \
           }
   
   #else /* !USE_HDR_CACHE */
   
   # define DECLARE_HDR_CACHE
   
   # define INIT_HDR_CACHE
   
   # define HC_GET_HDR(p, hhdr, source) \
           { \
             GET_HDR(p, hhdr); \
             if (IS_FORWARDING_ADDR_OR_NIL(hhdr)) { \
               ADVANCE(p, hhdr, source); \
             } \
           }
   #endif
   
 typedef struct bi {  typedef struct bi {
     hdr * index[BOTTOM_SZ];      hdr * index[BOTTOM_SZ];
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