1 files changed, 43 insertions, 60 deletions

diff --git a/gcc/tree-vect-stmts.cc b/gcc/tree-vect-stmts.cc
index a6f4db4..dbeb8bd 100644
--- a/gcc/tree-vect-stmts.cc
+++ b/gcc/tree-vect-stmts.cc
@@ -2400,70 +2400,26 @@ get_load_store_type (vec_info  *vinfo, stmt_vec_info stmt_info,
       /* We can only peel for loops, of course.  */
       gcc_checking_assert (loop_vinfo);
 
+      poly_uint64 vf = LOOP_VINFO_VECT_FACTOR (loop_vinfo);
+      poly_uint64 read_amount
+	= vf * TREE_INT_CST_LOW (TYPE_SIZE_UNIT (TREE_TYPE (vectype)));
+      if (STMT_VINFO_GROUPED_ACCESS (stmt_info))
+	read_amount *= DR_GROUP_SIZE (DR_GROUP_FIRST_ELEMENT (stmt_info));
+
       auto target_alignment
 	= DR_TARGET_ALIGNMENT (STMT_VINFO_DR_INFO (stmt_info));
-      unsigned HOST_WIDE_INT target_align;
-
-      bool group_aligned = false;
-      if (target_alignment.is_constant (&target_align)
-	  && nunits.is_constant ())
-	{
-	  poly_uint64 vf = LOOP_VINFO_VECT_FACTOR (loop_vinfo);
-	  auto vectype_size
-	    = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (TREE_TYPE (vectype)));
-	  poly_uint64 required_alignment = vf * vectype_size;
-	  /* If we have a grouped access we require that the alignment be N * elem.  */
-	  if (STMT_VINFO_GROUPED_ACCESS (stmt_info))
-	    required_alignment *=
-		DR_GROUP_SIZE (DR_GROUP_FIRST_ELEMENT (stmt_info));
-	  if (!multiple_p (target_alignment, required_alignment))
-	    {
-	      if (dump_enabled_p ())
-		dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
-			     "desired alignment %wu not met. Instead got %wu "
-			     "for DR alignment at %G",
-			     required_alignment.to_constant (),
-			     target_align, STMT_VINFO_STMT (stmt_info));
-	      return false;
-	    }
-
-	  if (!pow2p_hwi (target_align))
-	    {
-	      if (dump_enabled_p ())
-		dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
-			     "non-power-of-two vector alignment %wd "
-			     "for DR alignment at %G",
-			     target_align, STMT_VINFO_STMT (stmt_info));
-	      return false;
-	    }
-
-	  /* For VLA we have to insert a runtime check that the vector loads
-	     per iterations don't exceed a page size.  For now we can use
-	     POLY_VALUE_MAX as a proxy as we can't peel for VLA.  */
-	  if (known_gt (required_alignment, (unsigned)param_min_pagesize))
+      if (!multiple_p (target_alignment, read_amount))
+	{
+	  if (dump_enabled_p ())
 	    {
-	      if (dump_enabled_p ())
-		{
-		  dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
-			       "alignment required for correctness (");
-		  dump_dec (MSG_MISSED_OPTIMIZATION, required_alignment);
-		  dump_printf (MSG_NOTE, ") may exceed page size\n");
-		}
-	      return false;
+	      dump_printf_loc (MSG_NOTE, vect_location,
+			       "desired alignment not met, target was ");
+	      dump_dec (MSG_NOTE, target_alignment);
+	      dump_printf (MSG_NOTE, " previously, but read amount is ");
+	      dump_dec (MSG_NOTE, read_amount);
+	      dump_printf (MSG_NOTE, " at %G.\n", STMT_VINFO_STMT (stmt_info));
 	    }
-
-	  group_aligned = true;
-	}
-
-      /* There are multiple loads that have a misalignment that we couldn't
-	 align.  We would need LOOP_VINFO_MUST_USE_PARTIAL_VECTORS_P to
-	 vectorize. */
-      if (!group_aligned)
-	{
-	  if (inbounds)
-	    LOOP_VINFO_MUST_USE_PARTIAL_VECTORS_P (loop_vinfo) = true;
-	  else
-	    return false;
+	  return false;
 	}
 
       /* When using a group access the first element may be aligned but the
@@ -2485,6 +2441,33 @@ get_load_store_type (vec_info  *vinfo, stmt_vec_info stmt_info,
 			     STMT_VINFO_STMT (stmt_info));
 	  return false;
 	}
+
+      /* Reject vectorization if we know the read mount per vector iteration
+	 exceeds the min page size.  */
+      if (known_gt (read_amount, (unsigned) param_min_pagesize))
+	{
+	  if (dump_enabled_p ())
+	    {
+	      dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
+			       "alignment required for correctness (");
+	      dump_dec (MSG_MISSED_OPTIMIZATION, read_amount);
+	      dump_printf (MSG_NOTE, ") may exceed page size.\n");
+	    }
+	  return false;
+	}
+
+      if (!vf.is_constant ())
+	{
+	  /* For VLA modes, we need a runtime check to ensure any speculative
+	     read amount does not exceed the page size.  Here we record the max
+	     possible read amount for the check.  */
+	  if (maybe_gt (read_amount,
+			LOOP_VINFO_MAX_SPEC_READ_AMOUNT (loop_vinfo)))
+	    LOOP_VINFO_MAX_SPEC_READ_AMOUNT (loop_vinfo) = read_amount;
+
+	  /* For VLA modes, we must use partial vectors.  */
+	  LOOP_VINFO_MUST_USE_PARTIAL_VECTORS_P (loop_vinfo) = true;
+	}
     }
 
   if (*alignment_support_scheme == dr_unaligned_unsupported)