[18/77] Make int_mode_for_mode return an opt_scalar_int_mode

Also use int_mode_for_mode instead of (int_)mode_for_size
in cases where the requested size was the bitsize of an
existing 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 (opt_mode::else_blk): New function.
	(int_mode_for_mode): Declare.
	* stor-layout.c (int_mode_for_mode): Return an opt_scalar_int_mode.
	* builtins.c (expand_builtin_signbit): Adjust for new int_mode_for_mode
	return type.
	* cfgexpand.c (expand_debug_expr): Likewise.
	* combine.c (gen_lowpart_or_truncate): Likewise.
	(gen_lowpart_for_combine): Likewise.
	* config/aarch64/aarch64.c (aarch64_emit_approx_sqrt): Likewise.
	* config/avr/avr.c (avr_to_int_mode): Likewise.
	(avr_out_plus_1): Likewise.
	(avr_out_plus): Likewise.
	(avr_out_round): Likewise.
	* config/i386/i386.c (ix86_split_to_parts): Likewise.
	* config/s390/s390.c (s390_expand_vec_compare_cc): Likewise.
	(s390_expand_vcond): Likewise.
	* config/spu/spu.c (spu_split_immediate): Likewise.
	(spu_expand_mov): Likewise.
	* dse.c (get_stored_val): Likewise.
	* expmed.c (store_bit_field_1): Likewise.
	(convert_extracted_bit_field): Use int_mode_for_mode instead of
	int_mode_for_size.
	(extract_bit_field_1): Adjust for new int_mode_for_mode return type.
	(extract_low_bits): Likewise.
	* expr.c (emit_group_load_1): Likewise.  Separate out the BLKmode
	handling rather than repeating the check.
	(emit_group_store): Likewise.
	(emit_move_via_integer): Adjust for new int_mode_for_mode return type.
	* optabs.c (expand_absneg_bit): Likewise.
	(expand_copysign_absneg): Likewise.
	(expand_copysign_bit): Likewise.
	* tree-if-conv.c (ifcvt_can_use_mask_load_store): Likewise.
	* tree-vect-slp.c (vect_transform_slp_perm_load): Likewise.
	* tree-vect-stmts.c (vect_gen_perm_mask_any): Likewise.
	* var-tracking.c (prepare_call_arguments):  Likewise.
	* config/powerpcspe/powerpcspe.c (rs6000_do_expand_vec_perm): Use
	int_mode_for_mode instead of mode_for_size.
	* config/rs6000/rs6000.c (rs6000_do_expand_vec_perm): Likewise.

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

From-SVN: r251470

1 files changed, 23 insertions, 20 deletions

diff --git a/gcc/expr.c b/gcc/expr.c
index ac6f959..b9a0b06 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -2094,17 +2094,17 @@ emit_group_load_1 (rtx *tmps, rtx dst, rtx orig_src, tree type, int ssize)
       && !MEM_P (orig_src)
       && GET_CODE (orig_src) != CONCAT)
     {
-      machine_mode imode = int_mode_for_mode (GET_MODE (orig_src));
-      if (imode == BLKmode)
-	src = assign_stack_temp (GET_MODE (orig_src), ssize);
+      scalar_int_mode imode;
+      if (int_mode_for_mode (GET_MODE (orig_src)).exists (&imode))
+	{
+	  src = gen_reg_rtx (imode);
+	  emit_move_insn (gen_lowpart (GET_MODE (orig_src), src), orig_src);
+	}
       else
-	src = gen_reg_rtx (imode);
-      if (imode != BLKmode)
-	src = gen_lowpart (GET_MODE (orig_src), src);
-      emit_move_insn (src, orig_src);
-      /* ...and back again.  */
-      if (imode != BLKmode)
-	src = gen_lowpart (imode, src);
+	{
+	  src = assign_stack_temp (GET_MODE (orig_src), ssize);
+	  emit_move_insn (src, orig_src);
+	}
       emit_group_load_1 (tmps, dst, src, type, ssize);
       return;
     }
@@ -2368,14 +2368,18 @@ emit_group_store (rtx orig_dst, rtx src, tree type ATTRIBUTE_UNUSED, int ssize)
   if (!SCALAR_INT_MODE_P (m)
       && !MEM_P (orig_dst) && GET_CODE (orig_dst) != CONCAT)
     {
-      machine_mode imode = int_mode_for_mode (GET_MODE (orig_dst));
-      if (imode == BLKmode)
-        dst = assign_stack_temp (GET_MODE (orig_dst), ssize);
+      scalar_int_mode imode;
+      if (int_mode_for_mode (GET_MODE (orig_dst)).exists (&imode))
+	{
+	  dst = gen_reg_rtx (imode);
+	  emit_group_store (dst, src, type, ssize);
+	  dst = gen_lowpart (GET_MODE (orig_dst), dst);
+	}
       else
-        dst = gen_reg_rtx (imode);
-      emit_group_store (dst, src, type, ssize);
-      if (imode != BLKmode)
-        dst = gen_lowpart (GET_MODE (orig_dst), dst);
+	{
+	  dst = assign_stack_temp (GET_MODE (orig_dst), ssize);
+	  emit_group_store (dst, src, type, ssize);
+	}
       emit_move_insn (orig_dst, dst);
       return;
     }
@@ -3283,12 +3287,11 @@ emit_move_change_mode (machine_mode new_mode,
 static rtx_insn *
 emit_move_via_integer (machine_mode mode, rtx x, rtx y, bool force)
 {
-  machine_mode imode;
+  scalar_int_mode imode;
   enum insn_code code;
 
   /* There must exist a mode of the exact size we require.  */
-  imode = int_mode_for_mode (mode);
-  if (imode == BLKmode)
+  if (!int_mode_for_mode (mode).exists (&imode))
     return NULL;
 
   /* The target must support moves in this mode.  */