poly_int: expand_assignment

This patch makes the CONCAT handing in expand_assignment cope with
polynomial mode sizes.  The mode of the CONCAT must be complex,
so we can base the tests on the sizes of the real and imaginary
components.

2018-01-03  Richard Sandiford  <richard.sandiford@linaro.org>
	    Alan Hayward  <alan.hayward@arm.com>
	    David Sherwood  <david.sherwood@arm.com>

gcc/
	* expr.c (expand_assignment): Cope with polynomial mode sizes
	when assigning to a CONCAT.

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

From-SVN: r256199

gcc/ChangeLog

@@ -2,6 +2,13 @@
 	    Alan Hayward  <alan.hayward@arm.com>
 	    David Sherwood  <david.sherwood@arm.com>
 
+	* expr.c (expand_assignment): Cope with polynomial mode sizes
+	when assigning to a CONCAT.
+
+2018-01-03  Richard Sandiford  <richard.sandiford@linaro.org>
+	    Alan Hayward  <alan.hayward@arm.com>
+	    David Sherwood  <david.sherwood@arm.com>
+
 	* machmode.h (mode_precision): Change from unsigned short to
 	poly_uint16_pod.
 	(mode_to_precision): Return a poly_uint16 rather than an unsigned

gcc/expr.c

@@ -5131,25 +5131,28 @@ expand_assignment (tree to, tree from, bool nontemporal)
       /* Handle expand_expr of a complex value returning a CONCAT.  */
       else if (GET_CODE (to_rtx) == CONCAT)
 	{
-	  unsigned short mode_bitsize = GET_MODE_BITSIZE (GET_MODE (to_rtx));
+	  machine_mode to_mode = GET_MODE (to_rtx);
+	  gcc_checking_assert (COMPLEX_MODE_P (to_mode));
+	  poly_int64 mode_bitsize = GET_MODE_BITSIZE (to_mode);
+	  unsigned short inner_bitsize = GET_MODE_UNIT_BITSIZE (to_mode);
 	  if (TYPE_MODE (TREE_TYPE (from)) == GET_MODE (to_rtx)
 	      && COMPLEX_MODE_P (GET_MODE (to_rtx))
 	      && known_eq (bitpos, 0)
 	      && known_eq (bitsize, mode_bitsize))
 	    result = store_expr (from, to_rtx, false, nontemporal, reversep);
-	  else if (known_eq (bitsize, mode_bitsize / 2)
+	  else if (known_eq (bitsize, inner_bitsize)
 		   && (known_eq (bitpos, 0)
-		       || known_eq (bitpos, mode_bitsize / 2)))
+		       || known_eq (bitpos, inner_bitsize)))
 	    result = store_expr (from, XEXP (to_rtx, maybe_ne (bitpos, 0)),
 				 false, nontemporal, reversep);
-	  else if (known_le (bitpos + bitsize, mode_bitsize / 2))
+	  else if (known_le (bitpos + bitsize, inner_bitsize))
 	    result = store_field (XEXP (to_rtx, 0), bitsize, bitpos,
 				  bitregion_start, bitregion_end,
 				  mode1, from, get_alias_set (to),
 				  nontemporal, reversep);
-	  else if (known_ge (bitpos, mode_bitsize / 2))
+	  else if (known_ge (bitpos, inner_bitsize))
 	    result = store_field (XEXP (to_rtx, 1), bitsize,
-				  bitpos - mode_bitsize / 2,
+				  bitpos - inner_bitsize,
 				  bitregion_start, bitregion_end,
 				  mode1, from, get_alias_set (to),
 				  nontemporal, reversep);
@@ -5158,7 +5161,7 @@ expand_assignment (tree to, tree from, bool nontemporal)
 	      result = expand_normal (from);
 	      if (GET_CODE (result) == CONCAT)
 		{
-		  machine_mode to_mode = GET_MODE_INNER (GET_MODE (to_rtx));
+		  to_mode = GET_MODE_INNER (to_mode);
 		  machine_mode from_mode = GET_MODE_INNER (GET_MODE (result));
 		  rtx from_real
 		    = simplify_gen_subreg (to_mode, XEXP (result, 0),
@@ -5174,7 +5177,7 @@ expand_assignment (tree to, tree from, bool nontemporal)
 	      else
 		{
 		  rtx from_rtx
-		    = simplify_gen_subreg (GET_MODE (to_rtx), result,
+		    = simplify_gen_subreg (to_mode, result,
 					   TYPE_MODE (TREE_TYPE (from)), 0);
 		  if (from_rtx)
 		    {