contrib/gcc/tree-ssa-loop-prefetch.c

49 /* This pass inserts prefetch instructions to optimize cache usage during
53    2) For each of the references it decides when it is profitable to prefetch
57       PREFETCH_MOD (meaning that it only makes sense to prefetch in the
60       is no hardware sequential prefetch):
84    3) We determine how much ahead we need to prefetch.  The number of
90    4) Determine which of the references we prefetch.  We take into account
92       by machine description).  We prefetch as many prefetches as possible
102    6) We actually emit the prefetch instructions.  ??? Perhaps emit the
103       prefetch instructions with guards in cases where 5) was not sufficient
119    executed before the prefetch is completed.  */
131 /* True if write can be prefetched by a read prefetch.  */
137 /* True if read can be prefetched by a write prefetch. */
203   bool issue_prefetch_p;	/* Should we really issue the prefetch?  */
272 	 prefetch, or vice versa.  */
492 /* Prune the prefetch candidate REF using the self-reuse.  */
536 /* Prune the prefetch candidate REF using the reuse with BY.
552       /* If the references has the same address, only prefetch the
563 	 same cache line, prefetch just the first one.  */
652 /* Prune the prefetch candidate REF using the reuses with other references
684 /* Prune the prefetch candidates in GROUP using the reuse analysis.  */
703 	    fprintf (dump_file, " do not prefetch");
705 	    fprintf (dump_file, " prefetch once");
710 		  fprintf (dump_file, " prefetch before ");
716 		  fprintf (dump_file, " prefetch mod ");
726 /* Prune the list of prefetch candidates GROUPS using the reuse analysis.  */
735 /* Returns true if we should issue prefetch for REF.  */
748 /* Decide which of the prefetch candidates in GROUPS to prefetch.
749    AHEAD is the number of iterations to prefetch ahead (which corresponds
750    to the number of simultaneous instances of one prefetch running at a
752    unrolled.  Returns true if there is anything to prefetch.  */
816    HEAD is the number of iterations to prefetch ahead.  UNROLL_FACTOR
823   tree addr, addr_base, prefetch, params, write_p;
828     fprintf (dump_file, "Issued prefetch for %p.\n", (void *) ref);
839       /* Determine the address to prefetch.  */
845       /* Create the prefetch instruction.  */
850       prefetch = build_function_call_expr (built_in_decls[BUILT_IN_PREFETCH],
852       bsi_insert_before (&bsi, prefetch, BSI_SAME_STMT);
857    HEAD is the number of iterations to prefetch ahead.  UNROLL_FACTOR is the
897    of iterations ahead that we need to prefetch.  NINSNS is number of
932      prefetches, unroll the loop as much as needed to be able to prefetch
951 /* Issue prefetch instructions for array references in LOOP.  Returns
990   /* Step 4: what to prefetch?  */
1011 /* Issue prefetch instructions for array references in LOOPS.  */
1024 	 of processor costs and i486 does not have prefetch, but