Re: [reviewed] qsort comparator consistency checking

[Alexander Monakov <amonakov at ispras dot ru>]

On Fri, 29 Sep 2017, Andrew Pinski wrote:
> > This patch (r253295) breaks the gcc build for aarch64-linux-gnu:
> 
> I was just about to report the same thing.

I think autoprefetch ranking heuristic is still wrong if multi_mem_insn_p
may be true; please try this patch.

	* haifa-sched.c (autopref_rank_data): Remove.
	(autopref_rank_for_schedule): Only use min_offset difference.
	
diff --git a/gcc/haifa-sched.c b/gcc/haifa-sched.c
index 549e8961411..cea1242e1f1 100644
--- a/gcc/haifa-sched.c
+++ b/gcc/haifa-sched.c
@@ -5647,62 +5647,6 @@ autopref_multipass_init (const rtx_insn *insn, int write)
 }
 
 
-/* Helper for autopref_rank_for_schedule.  Given the data of two
-   insns relevant to the auto-prefetcher modelling code DATA1 and DATA2
-   return their comparison result.  Return 0 if there is no sensible
-   ranking order for the two insns.  */
-
-static int
-autopref_rank_data (autopref_multipass_data_t data1,
-		     autopref_multipass_data_t data2)
-{
-  /* Simple case when both insns are simple single memory ops.  */
-  if (!data1->multi_mem_insn_p && !data2->multi_mem_insn_p)
-    return data1->min_offset - data2->min_offset;
-
-  /* Two load/store multiple insns.  Return 0 if the offset ranges
-     overlap and the difference between the minimum offsets otherwise.  */
-  else if (data1->multi_mem_insn_p && data2->multi_mem_insn_p)
-    {
-      int min1 = data1->min_offset;
-      int max1 = data1->max_offset;
-      int min2 = data2->min_offset;
-      int max2 = data2->max_offset;
-
-      if (max1 < min2 || min1 > max2)
-	return min1 - min2;
-      else
-	return 0;
-    }
-
-  /* The other two cases is a pair of a load/store multiple and
-     a simple memory op.  Return 0 if the single op's offset is within the
-     range of the multi-op insn and the difference between the single offset
-     and the minimum offset of the multi-set insn otherwise.  */
-  else if (data1->multi_mem_insn_p && !data2->multi_mem_insn_p)
-    {
-      int max1 = data1->max_offset;
-      int min1 = data1->min_offset;
-
-      if (data2->min_offset >= min1
-	  && data2->min_offset <= max1)
-	return 0;
-      else
-	return min1 - data2->min_offset;
-    }
-  else
-    {
-      int max2 = data2->max_offset;
-      int min2 = data2->min_offset;
-
-      if (data1->min_offset >= min2
-	  && data1->min_offset <= max2)
-	return 0;
-      else
-	return data1->min_offset - min2;
-    }
-}
-
 /* Helper function for rank_for_schedule sorting.  */
 static int
 autopref_rank_for_schedule (const rtx_insn *insn1, const rtx_insn *insn2)
@@ -5725,7 +5669,7 @@ autopref_rank_for_schedule (const rtx_insn *insn1, const rtx_insn *insn2)
       int irrel2 = data2->status == AUTOPREF_MULTIPASS_DATA_IRRELEVANT;
 
       if (!irrel1 && !irrel2)
-	r = autopref_rank_data (data1, data2);
+	r = data1->min_offset - data2->min_offset;
       else
 	r = irrel2 - irrel1;
     }