poly_int: create_integer_operand

This patch generalises create_integer_operand so that it accepts
poly_int64s rather than HOST_WIDE_INTs.

2017-12-20  Richard Sandiford  <richard.sandiford@linaro.org>
	    Alan Hayward  <alan.hayward@arm.com>
	    David Sherwood  <david.sherwood@arm.com>

gcc/
	* optabs.h (expand_operand): Add an int_value field.
	(create_expand_operand): Add an int_value parameter and use it
	to initialize the new expand_operand field.
	(create_integer_operand): Replace with a declaration of a function
	that accepts poly_int64s.  Move the implementation to...
	* optabs.c (create_integer_operand): ...here.
	(maybe_legitimize_operand): For EXPAND_INTEGER, check whether
	the mode preserves the value of int_value, instead of calling
	const_int_operand on the rtx.  Use gen_int_mode to generate
	the new rtx.

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

From-SVN: r255865

1 files changed, 21 insertions, 2 deletions

diff --git a/gcc/optabs.c b/gcc/optabs.c
index b0d82af..9fd0f82 100644
--- a/gcc/optabs.c
+++ b/gcc/optabs.c
@@ -6979,6 +6979,20 @@ valid_multiword_target_p (rtx target)
   return true;
 }
 
+/* Make OP describe an input operand that has value INTVAL and that has
+   no inherent mode.  This function should only be used for operands that
+   are always expand-time constants.  The backend may request that INTVAL
+   be copied into a different kind of rtx, but it must specify the mode
+   of that rtx if so.  */
+
+void
+create_integer_operand (struct expand_operand *op, poly_int64 intval)
+{
+  create_expand_operand (op, EXPAND_INTEGER,
+			 gen_int_mode (intval, MAX_MODE_INT),
+			 VOIDmode, false, intval);
+}
+
 /* Like maybe_legitimize_operand, but do not change the code of the
    current rtx value.  */
 
@@ -7091,8 +7105,13 @@ maybe_legitimize_operand (enum insn_code icode, unsigned int opno,
 
     case EXPAND_INTEGER:
       mode = insn_data[(int) icode].operand[opno].mode;
-      if (mode != VOIDmode && const_int_operand (op->value, mode))
-	goto input;
+      if (mode != VOIDmode
+	  && known_eq (trunc_int_for_mode (op->int_value, mode),
+		       op->int_value))
+	{
+	  op->value = gen_int_mode (op->int_value, mode);
+	  goto input;
+	}
       break;
     }
   return insn_operand_matches (icode, opno, op->value);