[17/77] Add an int_mode_for_size helper function

This patch adds a wrapper around mode_for_size for cases in which
the mode class is MODE_INT (the commonest case).  The return type
can then be an opt_scalar_int_mode instead of a machine_mode.

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

gcc/
	* machmode.h (int_mode_for_size): New function.
	* builtins.c (set_builtin_user_assembler_name): Use int_mode_for_size
	instead of mode_for_size.
	* calls.c (save_fixed_argument_area): Likewise.  Make use of BLKmode
	explicit.
	* combine.c (expand_field_assignment): Use int_mode_for_size
	instead of mode_for_size.
	(make_extraction): Likewise.
	(simplify_shift_const_1): Likewise.
	(simplify_comparison): Likewise.
	* dojump.c (do_jump): Likewise.
	* dwarf2out.c (mem_loc_descriptor): Likewise.
	* emit-rtl.c (init_derived_machine_modes): Likewise.
	* expmed.c (flip_storage_order): Likewise.
	(convert_extracted_bit_field): Likewise.
	* expr.c (copy_blkmode_from_reg): Likewise.
	* graphite-isl-ast-to-gimple.c (max_mode_int_precision): Likewise.
	* internal-fn.c (expand_mul_overflow): Likewise.
	* lower-subreg.c (simple_move): Likewise.
	* optabs-libfuncs.c (init_optabs): Likewise.
	* simplify-rtx.c (simplify_unary_operation_1): Likewise.
	* tree.c (vector_type_mode): Likewise.
	* tree-ssa-strlen.c (handle_builtin_memcmp): Likewise.
	* tree-vect-data-refs.c (vect_lanes_optab_supported_p): Likewise.
	* tree-vect-generic.c (expand_vector_parallel): Likewise.
	* tree-vect-stmts.c (vectorizable_load): Likewise.
	(vectorizable_store): Likewise.

gcc/ada/
	* gcc-interface/decl.c (gnat_to_gnu_entity): Use int_mode_for_size
	instead of mode_for_size.
	(gnat_to_gnu_subprog_type): Likewise.
	* gcc-interface/utils.c (make_type_from_size): Likewise.

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

From-SVN: r251469

1 files changed, 7 insertions, 11 deletions

diff --git a/gcc/expmed.c b/gcc/expmed.c
index 48a0060..4c39096 100644
--- a/gcc/expmed.c
+++ b/gcc/expmed.c
@@ -364,7 +364,7 @@ check_reverse_float_storage_order_support (void)
 rtx
 flip_storage_order (machine_mode mode, rtx x)
 {
-  machine_mode int_mode;
+  scalar_int_mode int_mode;
   rtx result;
 
   if (mode == QImode)
@@ -384,16 +384,13 @@ flip_storage_order (machine_mode mode, rtx x)
   if (__builtin_expect (reverse_storage_order_supported < 0, 0))
     check_reverse_storage_order_support ();
 
-  if (SCALAR_INT_MODE_P (mode))
-    int_mode = mode;
-  else
+  if (!is_a <scalar_int_mode> (mode, &int_mode))
     {
       if (FLOAT_MODE_P (mode)
 	  && __builtin_expect (reverse_float_storage_order_supported < 0, 0))
 	check_reverse_float_storage_order_support ();
 
-      int_mode = mode_for_size (GET_MODE_PRECISION (mode), MODE_INT, 0);
-      if (int_mode == BLKmode)
+      if (!int_mode_for_size (GET_MODE_PRECISION (mode), 0).exists (&int_mode))
 	{
 	  sorry ("reverse storage order for %smode", GET_MODE_NAME (mode));
 	  return x;
@@ -1429,11 +1426,10 @@ convert_extracted_bit_field (rtx x, machine_mode mode,
      value via a SUBREG.  */
   if (!SCALAR_INT_MODE_P (tmode))
     {
-      machine_mode smode;
-
-      smode = mode_for_size (GET_MODE_BITSIZE (tmode), MODE_INT, 0);
-      x = convert_to_mode (smode, x, unsignedp);
-      x = force_reg (smode, x);
+      scalar_int_mode int_mode
+	= int_mode_for_size (GET_MODE_BITSIZE (tmode), 0).require ();
+      x = convert_to_mode (int_mode, x, unsignedp);
+      x = force_reg (int_mode, x);
       return gen_lowpart (tmode, x);
     }