[24/77] Replace a != BLKmode check with is_a <scalar_int_mode>

This patch replaces a check against BLKmode with a check
of is_a <scalar_int_mode>, in a case where scalar integer
modes were the only useful alternatives left.

gcc/
2017-08-30  Richard Sandiford  <richard.sandiford@linaro.org>
	    Alan Hayward  <alan.hayward@arm.com>
	    David Sherwood  <david.sherwood@arm.com>

	* gimple-fold.c (gimple_fold_builtin_memory_op): Use
	is_a <scalar_int_mode> instead of != BLKmode.

From-SVN: r251476

gcc/gimple-fold.c

@@ -748,31 +748,29 @@ gimple_fold_builtin_memory_op (gimple_stmt_iterator *gsi,
 	  unsigned ilen = tree_to_uhwi (len);
 	  if (pow2p_hwi (ilen))
 	    {
+	      scalar_int_mode mode;
 	      tree type = lang_hooks.types.type_for_size (ilen * 8, 1);
 	      if (type
-		  && TYPE_MODE (type) != BLKmode
-		  && (GET_MODE_SIZE (TYPE_MODE (type)) * BITS_PER_UNIT
-		      == ilen * 8)
+		  && is_a <scalar_int_mode> (TYPE_MODE (type), &mode)
+		  && GET_MODE_SIZE (mode) * BITS_PER_UNIT == ilen * 8
 		  /* If the destination pointer is not aligned we must be able
 		     to emit an unaligned store.  */
-		  && (dest_align >= GET_MODE_ALIGNMENT (TYPE_MODE (type))
-		      || !SLOW_UNALIGNED_ACCESS (TYPE_MODE (type), dest_align)
-		      || (optab_handler (movmisalign_optab, TYPE_MODE (type))
+		  && (dest_align >= GET_MODE_ALIGNMENT (mode)
+		      || !SLOW_UNALIGNED_ACCESS (mode, dest_align)
+		      || (optab_handler (movmisalign_optab, mode)
 			  != CODE_FOR_nothing)))
 		{
 		  tree srctype = type;
 		  tree desttype = type;
-		  if (src_align < GET_MODE_ALIGNMENT (TYPE_MODE (type)))
+		  if (src_align < GET_MODE_ALIGNMENT (mode))
 		    srctype = build_aligned_type (type, src_align);
 		  tree srcmem = fold_build2 (MEM_REF, srctype, src, off0);
 		  tree tem = fold_const_aggregate_ref (srcmem);
 		  if (tem)
 		    srcmem = tem;
-		  else if (src_align < GET_MODE_ALIGNMENT (TYPE_MODE (type))
-			   && SLOW_UNALIGNED_ACCESS (TYPE_MODE (type),
-						     src_align)
-			   && (optab_handler (movmisalign_optab,
-					      TYPE_MODE (type))
+		  else if (src_align < GET_MODE_ALIGNMENT (mode)
+			   && SLOW_UNALIGNED_ACCESS (mode, src_align)
+			   && (optab_handler (movmisalign_optab, mode)
 			       == CODE_FOR_nothing))
 		    srcmem = NULL_TREE;
 		  if (srcmem)
@@ -788,7 +786,7 @@ gimple_fold_builtin_memory_op (gimple_stmt_iterator *gsi,
 			  gimple_set_vuse (new_stmt, gimple_vuse (stmt));
 			  gsi_insert_before (gsi, new_stmt, GSI_SAME_STMT);
 			}
-		      if (dest_align < GET_MODE_ALIGNMENT (TYPE_MODE (type)))
+		      if (dest_align < GET_MODE_ALIGNMENT (mode))
 			desttype = build_aligned_type (type, dest_align);
 		      new_stmt
 			= gimple_build_assign (fold_build2 (MEM_REF, desttype,