diff mbox

[17/67] Add an int_mode_for_size helper function

Message ID 87fulxmeyg.fsf@e105548-lin.cambridge.arm.com
State New
Headers show

Commit Message

Richard Sandiford Dec. 9, 2016, 1:04 p.m. UTC
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.

gcc/
2016-11-24  Richard Sandiford  <richard.sandiford@arm.com>
	    Alan Hayward  <alan.hayward@arm.com>
	    David Sherwood  <david.sherwood@arm.com>

	* 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.
	* stor-layout.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.

gcc/ada/
2016-11-24  Richard Sandiford  <richard.sandiford@arm.com>
	    Alan Hayward  <alan.hayward@arm.com>
	    David Sherwood  <david.sherwood@arm.com>

	* 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.
diff mbox

Patch

diff --git a/gcc/ada/gcc-interface/decl.c b/gcc/ada/gcc-interface/decl.c
index d3bee34..843024e 100644
--- a/gcc/ada/gcc-interface/decl.c
+++ b/gcc/ada/gcc-interface/decl.c
@@ -3859,11 +3859,12 @@  gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, bool definition)
 	/* True if we make a dummy type here.  */
 	bool made_dummy = false;
 	/* The mode to be used for the pointer type.  */
-	machine_mode p_mode = mode_for_size (esize, MODE_INT, 0);
+	scalar_int_mode p_mode;
 	/* The GCC type used for the designated type.  */
 	tree gnu_desig_type = NULL_TREE;
 
-	if (!targetm.valid_pointer_mode (p_mode))
+	if (!int_mode_for_size (esize, 0).exists (&p_mode)
+	    || !targetm.valid_pointer_mode (p_mode))
 	  p_mode = ptr_mode;
 
 	/* If either the designated type or its full view is an unconstrained
@@ -6113,12 +6114,11 @@  gnat_to_gnu_subprog_type (Entity_Id gnat_subprog, bool definition,
 	      unsigned int size
 		= TREE_INT_CST_LOW (TYPE_SIZE (gnu_cico_return_type));
 	      unsigned int i = BITS_PER_UNIT;
-	      machine_mode mode;
+	      scalar_int_mode mode;
 
 	      while (i < size)
 		i <<= 1;
-	      mode = mode_for_size (i, MODE_INT, 0);
-	      if (mode != BLKmode)
+	      if (int_mode_for_size (i, 0).exists (&mode))
 		{
 		  SET_TYPE_MODE (gnu_cico_return_type, mode);
 		  SET_TYPE_ALIGN (gnu_cico_return_type,
diff --git a/gcc/ada/gcc-interface/utils.c b/gcc/ada/gcc-interface/utils.c
index 29e5203..937691c 100644
--- a/gcc/ada/gcc-interface/utils.c
+++ b/gcc/ada/gcc-interface/utils.c
@@ -1151,8 +1151,9 @@  make_type_from_size (tree type, tree size_tree, bool for_biased)
 	 may need to return the thin pointer.  */
       if (TYPE_FAT_POINTER_P (type) && size < POINTER_SIZE * 2)
 	{
-	  machine_mode p_mode = mode_for_size (size, MODE_INT, 0);
-	  if (!targetm.valid_pointer_mode (p_mode))
+	  scalar_int_mode p_mode;
+	  if (!int_mode_for_size (size, 0).exists (&p_mode)
+	      || !targetm.valid_pointer_mode (p_mode))
 	    p_mode = ptr_mode;
 	  return
 	    build_pointer_type_for_mode
diff --git a/gcc/builtins.c b/gcc/builtins.c
index 6de9a33..655ae27 100644
--- a/gcc/builtins.c
+++ b/gcc/builtins.c
@@ -10250,9 +10250,9 @@  set_builtin_user_assembler_name (tree decl, const char *asmspec)
   if (DECL_FUNCTION_CODE (decl) == BUILT_IN_FFS
       && INT_TYPE_SIZE < BITS_PER_WORD)
     {
+      scalar_int_mode mode = *int_mode_for_size (INT_TYPE_SIZE, 0);
       set_user_assembler_libfunc ("ffs", asmspec);
-      set_optab_libfunc (ffs_optab, mode_for_size (INT_TYPE_SIZE, MODE_INT, 0),
-			 "ffs");
+      set_optab_libfunc (ffs_optab, mode, "ffs");
     }
 }
 
diff --git a/gcc/calls.c b/gcc/calls.c
index fcfee25..7e58e14 100644
--- a/gcc/calls.c
+++ b/gcc/calls.c
@@ -1025,7 +1025,6 @@  save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_sa
     if (stack_usage_map[low] != 0)
       {
 	int num_to_save;
-	machine_mode save_mode;
 	int delta;
 	rtx addr;
 	rtx stack_area;
@@ -1038,13 +1037,16 @@  save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_sa
 	*high_to_save = high;
 
 	num_to_save = high - low + 1;
-	save_mode = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
+
+	opt_scalar_int_mode save_mode
+	  = int_mode_for_size (num_to_save * BITS_PER_UNIT, 1);
 
 	/* If we don't have the required alignment, must do this
 	   in BLKmode.  */
-	if ((low & (MIN (GET_MODE_SIZE (save_mode),
-			 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
-	  save_mode = BLKmode;
+	if (save_mode.exists ()
+	    && (low & (MIN (GET_MODE_SIZE (*save_mode),
+			    BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
+	  save_mode = opt_scalar_int_mode ();
 
 	if (ARGS_GROW_DOWNWARD)
 	  delta = -high;
@@ -1052,18 +1054,21 @@  save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_sa
 	  delta = low;
 
 	addr = plus_constant (Pmode, argblock, delta);
-	stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, addr));
 
-	set_mem_align (stack_area, PARM_BOUNDARY);
-	if (save_mode == BLKmode)
+	if (!save_mode.exists ())
 	  {
+	    stack_area = gen_rtx_MEM (BLKmode, memory_address (BLKmode, addr));
+	    set_mem_align (stack_area, PARM_BOUNDARY);
 	    save_area = assign_stack_temp (BLKmode, num_to_save);
 	    emit_block_move (validize_mem (save_area), stack_area,
 			     GEN_INT (num_to_save), BLOCK_OP_CALL_PARM);
 	  }
 	else
 	  {
-	    save_area = gen_reg_rtx (save_mode);
+	    stack_area = gen_rtx_MEM (*save_mode,
+				      memory_address (*save_mode, addr));
+	    set_mem_align (stack_area, PARM_BOUNDARY);
+	    save_area = gen_reg_rtx (*save_mode);
 	    emit_move_insn (save_area, stack_area);
 	  }
 
diff --git a/gcc/combine.c b/gcc/combine.c
index e8e0b3f..ed4f755 100644
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -7283,19 +7283,16 @@  expand_field_assignment (const_rtx x)
       /* Don't attempt bitwise arithmetic on non scalar integer modes.  */
       if (! SCALAR_INT_MODE_P (compute_mode))
 	{
-	  machine_mode imode;
-
 	  /* Don't do anything for vector or complex integral types.  */
 	  if (! FLOAT_MODE_P (compute_mode))
 	    break;
 
 	  /* Try to find an integral mode to pun with.  */
-	  imode = mode_for_size (GET_MODE_BITSIZE (compute_mode), MODE_INT, 0);
-	  if (imode == BLKmode)
+	  if (!int_mode_for_size (GET_MODE_BITSIZE (compute_mode), 0)
+	      .exists (&compute_mode))
 	    break;
 
-	  compute_mode = imode;
-	  inner = gen_lowpart (imode, inner);
+	  inner = gen_lowpart (compute_mode, inner);
 	}
 
       /* Compute a mask of LEN bits, if we can do this on the host machine.  */
@@ -7366,7 +7363,6 @@  make_extraction (machine_mode mode, rtx inner, HOST_WIDE_INT pos,
   machine_mode wanted_inner_reg_mode = word_mode;
   machine_mode pos_mode = word_mode;
   machine_mode extraction_mode = word_mode;
-  machine_mode tmode = mode_for_size (len, MODE_INT, 1);
   rtx new_rtx = 0;
   rtx orig_pos_rtx = pos_rtx;
   HOST_WIDE_INT orig_pos;
@@ -7414,7 +7410,8 @@  make_extraction (machine_mode mode, rtx inner, HOST_WIDE_INT pos,
      For MEM, we can avoid an extract if the field starts on an appropriate
      boundary and we can change the mode of the memory reference.  */
 
-  if (tmode != BLKmode
+  scalar_int_mode tmode;
+  if (int_mode_for_size (len, 1).exists (&tmode)
       && ((pos_rtx == 0 && (pos % BITS_PER_WORD) == 0
 	   && !MEM_P (inner)
 	   && (pos == 0 || REG_P (inner))
@@ -10418,8 +10415,8 @@  simplify_shift_const_1 (enum rtx_code code, machine_mode result_mode,
 	      && ! mode_dependent_address_p (XEXP (varop, 0),
 					     MEM_ADDR_SPACE (varop))
 	      && ! MEM_VOLATILE_P (varop)
-	      && (tmode = mode_for_size (GET_MODE_BITSIZE (mode) - count,
-					 MODE_INT, 1)) != BLKmode)
+	      && (int_mode_for_size (GET_MODE_BITSIZE (mode) - count, 1)
+		  .exists (&tmode)))
 	    {
 	      new_rtx = adjust_address_nv (varop, tmode,
 				       BYTES_BIG_ENDIAN ? 0
@@ -12334,7 +12331,7 @@  simplify_comparison (enum rtx_code code, rtx *pop0, rtx *pop1)
 				   & GET_MODE_MASK (mode))
 				  + 1)) >= 0
 	      && const_op >> i == 0
-	      && (tmode = mode_for_size (i, MODE_INT, 1)) != BLKmode)
+	      && int_mode_for_size (i, 1).exists (&tmode))
 	    {
 	      op0 = gen_lowpart_or_truncate (tmode, XEXP (op0, 0));
 	      continue;
@@ -12494,8 +12491,8 @@  simplify_comparison (enum rtx_code code, rtx *pop0, rtx *pop1)
 	      && CONST_INT_P (XEXP (op0, 1))
 	      && GET_CODE (XEXP (op0, 0)) == ASHIFT
 	      && XEXP (op0, 1) == XEXP (XEXP (op0, 0), 1)
-	      && (tmode = mode_for_size (mode_width - INTVAL (XEXP (op0, 1)),
-					 MODE_INT, 1)) != BLKmode
+	      && (int_mode_for_size (mode_width - INTVAL (XEXP (op0, 1)), 1)
+		  .exists (&tmode))
 	      && (((unsigned HOST_WIDE_INT) const_op
 		   + (GET_MODE_MASK (tmode) >> 1) + 1)
 		  <= GET_MODE_MASK (tmode)))
@@ -12513,8 +12510,8 @@  simplify_comparison (enum rtx_code code, rtx *pop0, rtx *pop1)
 	      && CONST_INT_P (XEXP (XEXP (op0, 0), 1))
 	      && GET_CODE (XEXP (XEXP (op0, 0), 0)) == ASHIFT
 	      && XEXP (op0, 1) == XEXP (XEXP (XEXP (op0, 0), 0), 1)
-	      && (tmode = mode_for_size (mode_width - INTVAL (XEXP (op0, 1)),
-					 MODE_INT, 1)) != BLKmode
+	      && (int_mode_for_size (mode_width - INTVAL (XEXP (op0, 1)), 1)
+		  .exists (&tmode))
 	      && (((unsigned HOST_WIDE_INT) const_op
 		   + (GET_MODE_MASK (tmode) >> 1) + 1)
 		  <= GET_MODE_MASK (tmode)))
diff --git a/gcc/dojump.c b/gcc/dojump.c
index e6ddf78..1195599 100644
--- a/gcc/dojump.c
+++ b/gcc/dojump.c
@@ -598,7 +598,7 @@  do_jump (tree exp, rtx_code_label *if_false_label,
           && TREE_CODE (TREE_OPERAND (exp, 1)) == INTEGER_CST
           && TYPE_PRECISION (TREE_TYPE (exp)) <= HOST_BITS_PER_WIDE_INT
           && (i = tree_floor_log2 (TREE_OPERAND (exp, 1))) >= 0
-          && (mode = mode_for_size (i + 1, MODE_INT, 0)) != BLKmode
+	  && int_mode_for_size (i + 1, 0).exists (&mode)
           && (type = lang_hooks.types.type_for_mode (mode, 1)) != 0
           && TYPE_PRECISION (type) < TYPE_PRECISION (TREE_TYPE (exp))
           && have_insn_for (COMPARE, TYPE_MODE (type)))
diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c
index 5130b64..568100d 100644
--- a/gcc/dwarf2out.c
+++ b/gcc/dwarf2out.c
@@ -15048,13 +15048,12 @@  mem_loc_descriptor (rtx rtl, machine_mode mode,
 	      || GET_MODE_BITSIZE (mode) == HOST_BITS_PER_DOUBLE_INT))
 	{
 	  dw_die_ref type_die = base_type_for_mode (mode, 1);
-	  machine_mode amode;
+	  scalar_int_mode amode;
 	  if (type_die == NULL)
 	    return NULL;
-	  amode = mode_for_size (DWARF2_ADDR_SIZE * BITS_PER_UNIT,
-				 MODE_INT, 0);
 	  if (INTVAL (rtl) >= 0
-	      && amode != BLKmode
+	      && (int_mode_for_size (DWARF2_ADDR_SIZE * BITS_PER_UNIT, 0)
+		  .exists (&amode))
 	      && trunc_int_for_mode (INTVAL (rtl), amode) == INTVAL (rtl)
 	      /* const DW_OP_convert <XXX> vs.
 		 DW_OP_const_type <XXX, 1, const>.  */
diff --git a/gcc/emit-rtl.c b/gcc/emit-rtl.c
index b9d87d3..569a478 100644
--- a/gcc/emit-rtl.c
+++ b/gcc/emit-rtl.c
@@ -5854,8 +5854,7 @@  init_derived_machine_modes (void)
 
   byte_mode = *opt_byte_mode;
   word_mode = *opt_word_mode;
-  ptr_mode = as_a <scalar_int_mode> (mode_for_size (POINTER_SIZE,
-						    MODE_INT, 0));
+  ptr_mode = *int_mode_for_size (POINTER_SIZE, 0);
 }
 
 /* Create some permanent unique rtl objects shared between all functions.  */
diff --git a/gcc/expmed.c b/gcc/expmed.c
index 737588b..fea62e6 100644
--- a/gcc/expmed.c
+++ b/gcc/expmed.c
@@ -363,7 +363,7 @@  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)
@@ -383,16 +383,13 @@  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;
@@ -1422,11 +1419,10 @@  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);
+      x = convert_to_mode (int_mode, x, unsignedp);
+      x = force_reg (int_mode, x);
       return gen_lowpart (tmode, x);
     }
 
diff --git a/gcc/expr.c b/gcc/expr.c
index d277a88..19b982c 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -2664,9 +2664,9 @@  copy_blkmode_from_reg (rtx target, rtx srcreg, tree type)
   copy_mode = word_mode;
   if (MEM_P (target))
     {
-      machine_mode mem_mode = mode_for_size (bitsize, MODE_INT, 1);
-      if (mem_mode != BLKmode)
-	copy_mode = mem_mode;
+      opt_scalar_int_mode mem_mode = int_mode_for_size (bitsize, 1);
+      if (mem_mode.exists ())
+	copy_mode = *mem_mode;
     }
   else if (REG_P (target) && GET_MODE_BITSIZE (tmode) < BITS_PER_WORD)
     copy_mode = tmode;
diff --git a/gcc/graphite-isl-ast-to-gimple.c b/gcc/graphite-isl-ast-to-gimple.c
index 209eada..0ceba85 100644
--- a/gcc/graphite-isl-ast-to-gimple.c
+++ b/gcc/graphite-isl-ast-to-gimple.c
@@ -61,7 +61,7 @@  along with GCC; see the file COPYING3.  If not see
    should use isl to derive the optimal type for each subexpression.  */
 
 static int max_mode_int_precision =
-  GET_MODE_PRECISION (mode_for_size (MAX_FIXED_MODE_SIZE, MODE_INT, 0));
+  GET_MODE_PRECISION (*int_mode_for_size (MAX_FIXED_MODE_SIZE, 0));
 static int graphite_expression_type_precision = 128 <= max_mode_int_precision ?
 						128 : max_mode_int_precision;
 
diff --git a/gcc/internal-fn.c b/gcc/internal-fn.c
index 3dbd2a1..cdcbaa4 100644
--- a/gcc/internal-fn.c
+++ b/gcc/internal-fn.c
@@ -1467,7 +1467,7 @@  expand_mul_overflow (location_t loc, tree lhs, tree arg0, tree arg1,
     {
       struct separate_ops ops;
       int prec = GET_MODE_PRECISION (mode);
-      machine_mode hmode = mode_for_size (prec / 2, MODE_INT, 1);
+      scalar_int_mode hmode;
       machine_mode wmode;
       ops.op0 = make_tree (type, op0);
       ops.op1 = make_tree (type, op1);
@@ -1503,7 +1503,8 @@  expand_mul_overflow (location_t loc, tree lhs, tree arg0, tree arg1,
 				       PROB_VERY_LIKELY);
 	    }
 	}
-      else if (hmode != BLKmode && 2 * GET_MODE_PRECISION (hmode) == prec)
+      else if (int_mode_for_size (prec / 2, 1).exists (&hmode)
+	       && 2 * GET_MODE_PRECISION (hmode) == prec)
 	{
 	  rtx_code_label *large_op0 = gen_label_rtx ();
 	  rtx_code_label *small_op0_large_op1 = gen_label_rtx ();
diff --git a/gcc/lower-subreg.c b/gcc/lower-subreg.c
index d378542..520eed1 100644
--- a/gcc/lower-subreg.c
+++ b/gcc/lower-subreg.c
@@ -349,8 +349,7 @@  simple_move (rtx_insn *insn, bool speed_p)
      size.  */
   mode = GET_MODE (SET_DEST (set));
   if (!SCALAR_INT_MODE_P (mode)
-      && (mode_for_size (GET_MODE_SIZE (mode) * BITS_PER_UNIT, MODE_INT, 0)
-	  == BLKmode))
+      && !int_mode_for_size (GET_MODE_BITSIZE (mode), 0).exists ())
     return NULL_RTX;
 
   /* Reject PARTIAL_INT modes.  They are used for processor specific
diff --git a/gcc/machmode.h b/gcc/machmode.h
index bf568c9..db011d3 100644
--- a/gcc/machmode.h
+++ b/gcc/machmode.h
@@ -558,6 +558,16 @@  extern const unsigned char mode_complex[NUM_MACHINE_MODES];
 
 extern machine_mode mode_for_size (unsigned int, enum mode_class, int);
 
+/* Return the machine mode to use for a MODE_INT of SIZE bits, if one
+   exists.  If LIMIT is nonzero, modes wider than MAX_FIXED_MODE_SIZE
+   will not be used.  */
+
+inline opt_scalar_int_mode
+int_mode_for_size (unsigned int size, int limit)
+{
+  return dyn_cast <scalar_int_mode> (mode_for_size (size, MODE_INT, limit));
+}
+
 /* Return the machine mode to use for a MODE_FLOAT of SIZE bits, if one
    exists.  */
 
diff --git a/gcc/optabs-libfuncs.c b/gcc/optabs-libfuncs.c
index 75fd677..a26577e 100644
--- a/gcc/optabs-libfuncs.c
+++ b/gcc/optabs-libfuncs.c
@@ -858,8 +858,10 @@  init_optabs (void)
   /* The ffs function operates on `int'.  Fall back on it if we do not
      have a libgcc2 function for that width.  */
   if (INT_TYPE_SIZE < BITS_PER_WORD)
-    set_optab_libfunc (ffs_optab, mode_for_size (INT_TYPE_SIZE, MODE_INT, 0),
-		       "ffs");
+    {
+      scalar_int_mode mode = *int_mode_for_size (INT_TYPE_SIZE, 0);
+      set_optab_libfunc (ffs_optab, mode, "ffs");
+    }
 
   /* Explicitly initialize the bswap libfuncs since we need them to be
      valid for things other than word_mode.  */
diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c
index 907c1e7..a1387b1 100644
--- a/gcc/simplify-rtx.c
+++ b/gcc/simplify-rtx.c
@@ -1482,12 +1482,11 @@  simplify_unary_operation_1 (enum rtx_code code, machine_mode mode, rtx op)
 	  && XEXP (XEXP (op, 0), 1) == XEXP (op, 1)
 	  && GET_MODE_BITSIZE (GET_MODE (op)) > INTVAL (XEXP (op, 1)))
 	{
-	  machine_mode tmode
-	    = mode_for_size (GET_MODE_BITSIZE (GET_MODE (op))
-			     - INTVAL (XEXP (op, 1)), MODE_INT, 1);
+	  scalar_int_mode tmode;
 	  gcc_assert (GET_MODE_BITSIZE (mode)
 		      > GET_MODE_BITSIZE (GET_MODE (op)));
-	  if (tmode != BLKmode)
+	  if (int_mode_for_size (GET_MODE_BITSIZE (GET_MODE (op))
+				 - INTVAL (XEXP (op, 1)), 1).exists (&tmode))
 	    {
 	      rtx inner =
 		rtl_hooks.gen_lowpart_no_emit (tmode, XEXP (XEXP (op, 0), 0));
@@ -1599,10 +1598,9 @@  simplify_unary_operation_1 (enum rtx_code code, machine_mode mode, rtx op)
 	  && XEXP (XEXP (op, 0), 1) == XEXP (op, 1)
 	  && GET_MODE_PRECISION (GET_MODE (op)) > INTVAL (XEXP (op, 1)))
 	{
-	  machine_mode tmode
-	    = mode_for_size (GET_MODE_PRECISION (GET_MODE (op))
-			     - INTVAL (XEXP (op, 1)), MODE_INT, 1);
-	  if (tmode != BLKmode)
+	  scalar_int_mode tmode;
+	  if (int_mode_for_size (GET_MODE_PRECISION (GET_MODE (op))
+				 - INTVAL (XEXP (op, 1)), 1).exists (&tmode))
 	    {
 	      rtx inner =
 		rtl_hooks.gen_lowpart_no_emit (tmode, XEXP (XEXP (op, 0), 0));
diff --git a/gcc/stor-layout.c b/gcc/stor-layout.c
index 2cde94e..49cce57 100644
--- a/gcc/stor-layout.c
+++ b/gcc/stor-layout.c
@@ -2444,10 +2444,11 @@  vector_type_mode (const_tree t)
       /* For integers, try mapping it to a same-sized scalar mode.  */
       if (GET_MODE_CLASS (innermode) == MODE_INT)
 	{
-	  mode = mode_for_size (TYPE_VECTOR_SUBPARTS (t)
-				* GET_MODE_BITSIZE (innermode), MODE_INT, 0);
-
-	  if (mode != VOIDmode && have_regs_of_mode[mode])
+	  unsigned int size = (TYPE_VECTOR_SUBPARTS (t)
+			       * GET_MODE_BITSIZE (innermode));
+	  scalar_int_mode mode;
+	  if (int_mode_for_size (size, 0).exists (&mode)
+	      && have_regs_of_mode[mode])
 	    return mode;
 	}
 
diff --git a/gcc/tree-ssa-strlen.c b/gcc/tree-ssa-strlen.c
index 339812e..a596005 100644
--- a/gcc/tree-ssa-strlen.c
+++ b/gcc/tree-ssa-strlen.c
@@ -1989,8 +1989,8 @@  handle_builtin_memcmp (gimple_stmt_iterator *gsi)
       unsigned align1 = get_pointer_alignment (arg1);
       unsigned align2 = get_pointer_alignment (arg2);
       unsigned align = MIN (align1, align2);
-      machine_mode mode = mode_for_size (leni, MODE_INT, 1);
-      if (mode != BLKmode
+      scalar_int_mode mode;
+      if (int_mode_for_size (leni, 1).exists (&mode)
 	  && (align >= leni || !SLOW_UNALIGNED_ACCESS (mode, align)))
 	{
 	  location_t loc = gimple_location (stmt2);
diff --git a/gcc/tree-vect-data-refs.c b/gcc/tree-vect-data-refs.c
index 5a30314..2d94d2c 100644
--- a/gcc/tree-vect-data-refs.c
+++ b/gcc/tree-vect-data-refs.c
@@ -58,15 +58,14 @@  static bool
 vect_lanes_optab_supported_p (const char *name, convert_optab optab,
 			      tree vectype, unsigned HOST_WIDE_INT count)
 {
-  machine_mode mode, array_mode;
+  machine_mode mode;
+  scalar_int_mode array_mode;
   bool limit_p;
 
   mode = TYPE_MODE (vectype);
   limit_p = !targetm.array_mode_supported_p (mode, count);
-  array_mode = mode_for_size (count * GET_MODE_BITSIZE (mode),
-			      MODE_INT, limit_p);
-
-  if (array_mode == BLKmode)
+  if (!int_mode_for_size (count * GET_MODE_BITSIZE (mode),
+			  limit_p).exists (&array_mode))
     {
       if (dump_enabled_p ())
 	dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
diff --git a/gcc/tree-vect-generic.c b/gcc/tree-vect-generic.c
index 91c5f93..4453e48 100644
--- a/gcc/tree-vect-generic.c
+++ b/gcc/tree-vect-generic.c
@@ -288,7 +288,6 @@  expand_vector_parallel (gimple_stmt_iterator *gsi, elem_op_func f, tree type,
 			enum tree_code code)
 {
   tree result, compute_type;
-  machine_mode mode;
   int n_words = tree_to_uhwi (TYPE_SIZE_UNIT (type)) / UNITS_PER_WORD;
   location_t loc = gimple_location (gsi_stmt (*gsi));
 
@@ -312,7 +311,8 @@  expand_vector_parallel (gimple_stmt_iterator *gsi, elem_op_func f, tree type,
   else
     {
       /* Use a single scalar operation with a mode no wider than word_mode.  */
-      mode = mode_for_size (tree_to_uhwi (TYPE_SIZE (type)), MODE_INT, 0);
+      scalar_int_mode mode
+	= *int_mode_for_size (tree_to_uhwi (TYPE_SIZE (type)), 0);
       compute_type = lang_hooks.types.type_for_mode (mode, 1);
       result = f (gsi, compute_type, a, b, NULL_TREE, NULL_TREE, code, type);
       warning_at (loc, OPT_Wvector_operation_performance,
diff --git a/gcc/tree-vect-stmts.c b/gcc/tree-vect-stmts.c
index 787ecea..1690cec 100644
--- a/gcc/tree-vect-stmts.c
+++ b/gcc/tree-vect-stmts.c
@@ -6992,7 +6992,7 @@  vectorizable_load (gimple *stmt, gimple_stmt_iterator *gsi, gimple **vec_stmt,
 		 to a larger load.  */
 	      unsigned lsize
 		= group_size * TYPE_PRECISION (TREE_TYPE (vectype));
-	      machine_mode elmode = mode_for_size (lsize, MODE_INT, 0);
+	      scalar_int_mode elmode = *int_mode_for_size (lsize, 0);
 	      machine_mode vmode = mode_for_vector (elmode,
 						    nunits / group_size);
 	      /* If we can't construct such a vector fall back to