+/* Expand a setmem pattern; return true if successful. */
+
+bool
+set_storage_via_setmem (rtx object, rtx size, rtx val, unsigned int align,
+ unsigned int expected_align, HOST_WIDE_INT expected_size)
+{
+ /* Try the most limited insn first, because there's no point
+ including more than one in the machine description unless
+ the more limited one has some advantage. */
+
+ rtx opalign = GEN_INT (align / BITS_PER_UNIT);
+ enum machine_mode mode;
+
+ if (expected_align < align)
+ expected_align = align;
+
+ for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT); mode != VOIDmode;
+ mode = GET_MODE_WIDER_MODE (mode))
+ {
+ enum insn_code code = setmem_optab[(int) mode];
+ insn_operand_predicate_fn pred;
+
+ if (code != CODE_FOR_nothing
+ /* We don't need MODE to be narrower than
+ BITS_PER_HOST_WIDE_INT here because if SIZE is less than
+ the mode mask, as it is returned by the macro, it will
+ definitely be less than the actual mode mask. */
+ && ((GET_CODE (size) == CONST_INT
+ && ((unsigned HOST_WIDE_INT) INTVAL (size)
+ <= (GET_MODE_MASK (mode) >> 1)))
+ || GET_MODE_BITSIZE (mode) >= BITS_PER_WORD)
+ && ((pred = insn_data[(int) code].operand[0].predicate) == 0
+ || (*pred) (object, BLKmode))
+ && ((pred = insn_data[(int) code].operand[3].predicate) == 0
+ || (*pred) (opalign, VOIDmode)))
+ {
+ rtx opsize, opchar;
+ enum machine_mode char_mode;
+ rtx last = get_last_insn ();
+ rtx pat;
+
+ opsize = convert_to_mode (mode, size, 1);
+ pred = insn_data[(int) code].operand[1].predicate;
+ if (pred != 0 && ! (*pred) (opsize, mode))
+ opsize = copy_to_mode_reg (mode, opsize);
+
+ opchar = val;
+ char_mode = insn_data[(int) code].operand[2].mode;
+ if (char_mode != VOIDmode)
+ {
+ opchar = convert_to_mode (char_mode, opchar, 1);
+ pred = insn_data[(int) code].operand[2].predicate;
+ if (pred != 0 && ! (*pred) (opchar, char_mode))
+ opchar = copy_to_mode_reg (char_mode, opchar);
+ }
+
+ if (insn_data[(int) code].n_operands == 4)
+ pat = GEN_FCN ((int) code) (object, opsize, opchar, opalign);
+ else
+ pat = GEN_FCN ((int) code) (object, opsize, opchar, opalign,
+ GEN_INT (expected_align),
+ GEN_INT (expected_size));
+ if (pat)
+ {
+ emit_insn (pat);
+ return true;
+ }
+ else
+ delete_insns_since (last);
+ }
+ }
+
+ return false;
+}
+
+\f