Improve debug output of loop data prefetching.

	* tree-ssa-loop-prefetch.c (struct mem_ref_group, struct mem_ref):
	New "uid" fields to hold pretty-print IDs of group and ref.
	Memory references are now identified as <group_id>:<ref_id>
	instead of using [random] addresses.
	(dump_mem_details): Simplify, no functional change.
	(dump_mem_ref): Simplify and make output more concise.
	Replace couple of fprintf's throughout code with calls to dump_mem_ref.
	(find_or_create_group): Initialize group uid.
	(record_ref): Initialize ref uid.  Improve debug output.
	(prune_group_by_reuse, should_issue_prefetch_p,)
	(should_issue_prefetch_p, schedule_prefetches, issue_prefetch_ref,)
	(mark_nontemporal_store, determine_loop_nest_reuse):
	Improve debug output.

Change-Id: Ia594d5854de96183f3c5a669c161e5a9a73a29d7

From-SVN: r248925

gcc/ChangeLog

 2017-06-06  Maxim Kuvyrkov  <maxim.kuvyrkov@linaro.org>
 
+        * tree-ssa-loop-prefetch.c (struct mem_ref_group, struct mem_ref):
+        New "uid" fields to hold pretty-print IDs of group and ref.
+        Memory references are now identified as <group_id>:<ref_id>
+        instead of using [random] addresses.
+        (dump_mem_details): Simplify, no functional change.
+        (dump_mem_ref): Simplify and make output more concise.
+        Replace couple of fprintf's throughout code with calls to dump_mem_ref.
+        (find_or_create_group): Initialize group uid.
+        (record_ref): Initialize ref uid.  Improve debug output.
+        (prune_group_by_reuse, should_issue_prefetch_p,)
+        (should_issue_prefetch_p, schedule_prefetches, issue_prefetch_ref,)
+        (mark_nontemporal_store, determine_loop_nest_reuse):
+        Improve debug output.
+
+2017-06-06  Maxim Kuvyrkov  <maxim.kuvyrkov@linaro.org>
+
         * dbgcnt.def (prefetch): New debug counter.
         * tree-ssa-loop-prefetch.c (dbgcnt.h): New include.
         (schedule_prefetches): Stop issueing prefetches if debug counter

gcc/tree-ssa-loop-prefetch.c

@@ -228,6 +228,7 @@ struct mem_ref_group
   tree step;			/* Step of the reference.  */
   struct mem_ref *refs;		/* References in the group.  */
   struct mem_ref_group *next;	/* Next group of references.  */
+  unsigned int uid;		/* Group UID, used only for debugging.  */
 };
 
 /* Assigned to PREFETCH_BEFORE when all iterations are to be prefetched.  */
@@ -270,6 +271,7 @@ struct mem_ref
   unsigned reuse_distance;	/* The amount of data accessed before the first
 				   reuse of this value.  */
   struct mem_ref *next;		/* The next reference in the group.  */
+  unsigned int uid;		/* Ref UID, used only for debugging.  */
   unsigned write_p : 1;		/* Is it a write?  */
   unsigned independent_p : 1;	/* True if the reference is independent on
 				   all other references inside the loop.  */
@@ -291,11 +293,8 @@ dump_mem_details (FILE *file, tree base, tree step,
   else
     print_generic_expr (file, step, TDF_SLIM);
   fprintf (file, ")\n");
-  fprintf (file, "  delta ");
-  fprintf (file, HOST_WIDE_INT_PRINT_DEC, delta);
-  fprintf (file, "\n");
-  fprintf (file, "  %s\n", write_p ? "write" : "read");
-  fprintf (file, "\n");
+  fprintf (file, "  delta " HOST_WIDE_INT_PRINT_DEC "\n", delta);
+  fprintf (file, "  %s\n\n", write_p ? "write" : "read");
 }
 
 /* Dumps information about reference REF to FILE.  */
@@ -303,12 +302,9 @@ dump_mem_details (FILE *file, tree base, tree step,
 static void
 dump_mem_ref (FILE *file, struct mem_ref *ref)
 {
-  fprintf (file, "Reference %p:\n", (void *) ref);
-
-  fprintf (file, "  group %p ", (void *) ref->group);
-
-  dump_mem_details (file, ref->group->base, ref->group->step, ref->delta,
-                   ref->write_p);
+  fprintf (file, "reference %u:%u (", ref->group->uid, ref->uid);
+  print_generic_expr (file, ref->mem, TDF_SLIM);
+  fprintf (file, ")\n");
 }
 
 /* Finds a group with BASE and STEP in GROUPS, or creates one if it does not
@@ -317,6 +313,9 @@ dump_mem_ref (FILE *file, struct mem_ref *ref)
 static struct mem_ref_group *
 find_or_create_group (struct mem_ref_group **groups, tree base, tree step)
 {
+  /* Global count for setting struct mem_ref_group->uid.  */
+  static unsigned int last_mem_ref_group_uid = 0;
+
   struct mem_ref_group *group;
 
   for (; *groups; groups = &(*groups)->next)
@@ -336,6 +335,7 @@ find_or_create_group (struct mem_ref_group **groups, tree base, tree step)
   group->base = base;
   group->step = step;
   group->refs = NULL;
+  group->uid = ++last_mem_ref_group_uid;
   group->next = *groups;
   *groups = group;
 
@@ -349,11 +349,14 @@ static void
 record_ref (struct mem_ref_group *group, gimple *stmt, tree mem,
 	    HOST_WIDE_INT delta, bool write_p)
 {
+  unsigned int last_mem_ref_uid = 0;
   struct mem_ref **aref;
 
   /* Do not record the same address twice.  */
   for (aref = &group->refs; *aref; aref = &(*aref)->next)
     {
+      last_mem_ref_uid = (*aref)->uid;
+
       /* It does not have to be possible for write reference to reuse the read
 	 prefetch, or vice versa.  */
       if (!WRITE_CAN_USE_READ_PREFETCH
@@ -382,9 +385,16 @@ record_ref (struct mem_ref_group *group, gimple *stmt, tree mem,
   (*aref)->next = NULL;
   (*aref)->independent_p = false;
   (*aref)->storent_p = false;
+  (*aref)->uid = last_mem_ref_uid + 1;
 
   if (dump_file && (dump_flags & TDF_DETAILS))
+    {
       dump_mem_ref (dump_file, *aref);
+
+      fprintf (dump_file, "  group %u ", group->uid);
+      dump_mem_details (dump_file, group->base, group->step, delta,
+			write_p);
+    }
 }
 
 /* Release memory references in GROUPS.  */
@@ -939,7 +949,7 @@ prune_group_by_reuse (struct mem_ref_group *group)
 
       if (dump_file && (dump_flags & TDF_DETAILS))
 	{
-	  fprintf (dump_file, "Reference %p:", (void *) ref_pruned);
+	  dump_mem_ref (dump_file, ref_pruned);
 
 	  if (ref_pruned->prefetch_before == PREFETCH_ALL
 	      && ref_pruned->prefetch_mod == 1)
@@ -987,8 +997,8 @@ should_issue_prefetch_p (struct mem_ref *ref)
   if (ref->prefetch_before != PREFETCH_ALL)
     {
       if (dump_file && (dump_flags & TDF_DETAILS))
-        fprintf (dump_file, "Ignoring %p due to prefetch_before\n",
-		 (void *) ref);
+        fprintf (dump_file, "Ignoring reference %u:%u due to prefetch_before\n",
+		 ref->group->uid, ref->uid);
       return false;
     }
 
@@ -996,7 +1006,7 @@ should_issue_prefetch_p (struct mem_ref *ref)
   if (ref->storent_p)
     {
       if (dump_file && (dump_flags & TDF_DETAILS))
-        fprintf (dump_file, "Ignoring nontemporal store %p\n", (void *) ref);
+        fprintf (dump_file, "Ignoring nontemporal store reference %u:%u\n", ref->group->uid, ref->uid);
       return false;
     }
 
@@ -1064,6 +1074,9 @@ schedule_prefetches (struct mem_ref_group *groups, unsigned unroll_factor,
 	  continue;
 
 	ref->issue_prefetch_p = true;
+	if (dump_file && (dump_flags & TDF_DETAILS))
+	  fprintf (dump_file, "Decided to issue prefetch for reference %u:%u\n",
+		   ref->group->uid, ref->uid);
 
 	if (remaining_prefetch_slots <= prefetch_slots)
 	  return true;
@@ -1127,9 +1140,9 @@ issue_prefetch_ref (struct mem_ref *ref, unsigned unroll_factor, unsigned ahead)
   bool nontemporal = ref->reuse_distance >= L2_CACHE_SIZE_BYTES;
 
   if (dump_file && (dump_flags & TDF_DETAILS))
-    fprintf (dump_file, "Issued%s prefetch for %p.\n",
+    fprintf (dump_file, "Issued%s prefetch for reference %u:%u.\n",
 	     nontemporal ? " nontemporal" : "",
-	     (void *) ref);
+	     ref->group->uid, ref->uid);
 
   bsi = gsi_for_stmt (ref->stmt);
 
@@ -1149,8 +1162,8 @@ issue_prefetch_ref (struct mem_ref *ref, unsigned unroll_factor, unsigned ahead)
           delta = (ahead + ap * ref->prefetch_mod) *
 		   int_cst_value (ref->group->step);
           addr = fold_build_pointer_plus_hwi (addr_base, delta);
-          addr = force_gimple_operand_gsi (&bsi, unshare_expr (addr), true, NULL,
-                                           true, GSI_SAME_STMT);
+          addr = force_gimple_operand_gsi (&bsi, unshare_expr (addr), true,
+					   NULL, true, GSI_SAME_STMT);
         }
       else
         {
@@ -1234,8 +1247,8 @@ mark_nontemporal_store (struct mem_ref *ref)
     return false;
 
   if (dump_file && (dump_flags & TDF_DETAILS))
-    fprintf (dump_file, "Marked reference %p as a nontemporal store.\n",
-	     (void *) ref);
+    fprintf (dump_file, "Marked reference %u:%u as a nontemporal store.\n",
+	     ref->group->uid, ref->uid);
 
   gimple_assign_set_nontemporal_move (ref->stmt, true);
   ref->storent_p = true;
@@ -1345,7 +1358,7 @@ should_unroll_loop_p (struct loop *loop, struct tree_niter_desc *desc,
 
 /* Determine the coefficient by that unroll LOOP, from the information
    contained in the list of memory references REFS.  Description of
-   umber of iterations of LOOP is stored to DESC.  NINSNS is the number of
+   number of iterations of LOOP is stored to DESC.  NINSNS is the number of
    insns of the LOOP.  EST_NITER is the estimated number of iterations of
    the loop, or -1 if no estimate is available.  */
 
@@ -1720,8 +1733,8 @@ determine_loop_nest_reuse (struct loop *loop, struct mem_ref_group *refs,
       fprintf (dump_file, "Reuse distances:\n");
       for (gr = refs; gr; gr = gr->next)
 	for (ref = gr->refs; ref; ref = ref->next)
-	  fprintf (dump_file, " ref %p distance %u\n",
-		   (void *) ref, ref->reuse_distance);
+	  fprintf (dump_file, " reference %u:%u distance %u\n",
+		   ref->group->uid, ref->uid, ref->reuse_distance);
     }
 
   return true;