[51/77] Use opt_scalar_int_mode when iterating over integer modes

This patch uses opt_scalar_int_mode rather than machine_mode
when iterating over scalar_int_modes, in cases where that helps
with future patches.  (Using machine_mode is still OK in places
that don't really care about the mode being a scalar integer.)

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

gcc/
	* cse.c (cse_insn): Use opt_scalar_int_mode for the mode iterator.
	* explow.c (hard_function_value): Likewise.
	* expmed.c (extract_fixed_bit_field_1): Likewise.  Move the
	convert_to_mode call outside the loop.
	* expr.c (alignment_for_piecewise_move): Use opt_scalar_int_mode
	for the mode iterator.  Require the mode specified by max_pieces
	to exist.
	(emit_block_move_via_movmem): Use opt_scalar_int_mode for the
	mode iterator.
	(copy_blkmode_to_reg): Likewise.
	(set_storage_via_setmem): Likewise.
	* optabs.c (prepare_cmp_insn): Likewise.
	* rtlanal.c (init_num_sign_bit_copies_in_rep): Likewise.
	* stor-layout.c (finish_bitfield_representative): Likewise.

gcc/fortran/
	* trans-types.c (gfc_init_kinds): Use opt_scalar_int_mode for
	the mode iterator.

Co-Authored-By: Alan Hayward <alan.hayward@arm.com>
Co-Authored-By: David Sherwood <david.sherwood@arm.com>

From-SVN: r251503

1 files changed, 16 insertions, 15 deletions

diff --git a/gcc/expr.c b/gcc/expr.c
index 7afb4cd..f95a7fe 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -699,18 +699,18 @@ convert_modes (machine_mode mode, machine_mode oldmode, rtx x, int unsignedp)
 static unsigned int
 alignment_for_piecewise_move (unsigned int max_pieces, unsigned int align)
 {
-  machine_mode tmode;
+  scalar_int_mode tmode
+    = int_mode_for_size (max_pieces * BITS_PER_UNIT, 1).require ();
 
-  tmode = mode_for_size (max_pieces * BITS_PER_UNIT, MODE_INT, 1);
   if (align >= GET_MODE_ALIGNMENT (tmode))
     align = GET_MODE_ALIGNMENT (tmode);
   else
     {
-      machine_mode tmode, xmode;
-
-      xmode = NARROWEST_INT_MODE;
-      FOR_EACH_MODE_IN_CLASS (tmode, MODE_INT)
+      scalar_int_mode xmode = NARROWEST_INT_MODE;
+      opt_scalar_int_mode mode_iter;
+      FOR_EACH_MODE_IN_CLASS (mode_iter, MODE_INT)
 	{
+	  tmode = mode_iter.require ();
 	  if (GET_MODE_SIZE (tmode) > max_pieces
 	      || SLOW_UNALIGNED_ACCESS (tmode, align))
 	    break;
@@ -1707,7 +1707,6 @@ emit_block_move_via_movmem (rtx x, rtx y, rtx size, unsigned int align,
 			    unsigned HOST_WIDE_INT probable_max_size)
 {
   int save_volatile_ok = volatile_ok;
-  machine_mode mode;
 
   if (expected_align < align)
     expected_align = align;
@@ -1726,8 +1725,10 @@ emit_block_move_via_movmem (rtx x, rtx y, rtx size, unsigned int align,
      including more than one in the machine description unless
      the more limited one has some advantage.  */
 
-  FOR_EACH_MODE_IN_CLASS (mode, MODE_INT)
+  opt_scalar_int_mode mode_iter;
+  FOR_EACH_MODE_IN_CLASS (mode_iter, MODE_INT)
     {
+      scalar_int_mode mode = mode_iter.require ();
       enum insn_code code = direct_optab_handler (movmem_optab, mode);
 
       if (code != CODE_FOR_nothing
@@ -2791,13 +2792,13 @@ copy_blkmode_to_reg (machine_mode mode, tree src)
     {
       /* Find the smallest integer mode large enough to hold the
 	 entire structure.  */
-      FOR_EACH_MODE_IN_CLASS (mode, MODE_INT)
-	/* Have we found a large enough mode?  */
-	if (GET_MODE_SIZE (mode) >= bytes)
+      opt_scalar_int_mode mode_iter;
+      FOR_EACH_MODE_IN_CLASS (mode_iter, MODE_INT)
+	if (GET_MODE_SIZE (mode_iter.require ()) >= bytes)
 	  break;
 
       /* A suitable mode should have been found.  */
-      gcc_assert (mode != VOIDmode);
+      mode = mode_iter.require ();
     }
 
   if (GET_MODE_SIZE (mode) < GET_MODE_SIZE (word_mode))
@@ -3035,8 +3036,6 @@ set_storage_via_setmem (rtx object, rtx size, rtx val, unsigned int align,
      including more than one in the machine description unless
      the more limited one has some advantage.  */
 
-  machine_mode mode;
-
   if (expected_align < align)
     expected_align = align;
   if (expected_size != -1)
@@ -3047,8 +3046,10 @@ set_storage_via_setmem (rtx object, rtx size, rtx val, unsigned int align,
 	expected_size = min_size;
     }
 
-  FOR_EACH_MODE_IN_CLASS (mode, MODE_INT)
+  opt_scalar_int_mode mode_iter;
+  FOR_EACH_MODE_IN_CLASS (mode_iter, MODE_INT)
     {
+      scalar_int_mode mode = mode_iter.require ();
       enum insn_code code = direct_optab_handler (setmem_optab, mode);
 
       if (code != CODE_FOR_nothing