-
- /* If the structure doesn't take up a whole number of words, see
- whether the register value should be padded on the left or on
- the right. Set PADDING_CORRECTION to the number of padding
- bits needed on the left side.
-
- In most ABIs, the structure will be returned at the least end of
- the register, which translates to right padding on little-endian
- targets and left padding on big-endian targets. The opposite
- holds if the structure is returned at the most significant
- end of the register. */
- if (bytes % UNITS_PER_WORD != 0
- && (targetm.calls.return_in_msb (TREE_TYPE (retval_rhs))
- ? !BYTES_BIG_ENDIAN
- : BYTES_BIG_ENDIAN))
- padding_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD)
- * BITS_PER_UNIT));
-
- /* Copy the structure BITSIZE bits at a time. */
- for (bitpos = 0, xbitpos = padding_correction;
- bitpos < bytes * BITS_PER_UNIT;
- bitpos += bitsize, xbitpos += bitsize)
- {
- /* We need a new destination pseudo each time xbitpos is
- on a word boundary and when xbitpos == padding_correction
- (the first time through). */
- if (xbitpos % BITS_PER_WORD == 0
- || xbitpos == padding_correction)
- {
- /* Generate an appropriate register. */
- dst = gen_reg_rtx (word_mode);
- result_pseudos[xbitpos / BITS_PER_WORD] = dst;
-
- /* Clear the destination before we move anything into it. */
- emit_move_insn (dst, CONST0_RTX (GET_MODE (dst)));
- }
-
- /* We need a new source operand each time bitpos is on a word
- boundary. */
- if (bitpos % BITS_PER_WORD == 0)
- src = operand_subword_force (result_val,
- bitpos / BITS_PER_WORD,
- BLKmode);
-
- /* Use bitpos for the source extraction (left justified) and
- xbitpos for the destination store (right justified). */
- store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode,
- extract_bit_field (src, bitsize,
- bitpos % BITS_PER_WORD, 1,
- NULL_RTX, word_mode, word_mode));
- }
-
- tmpmode = GET_MODE (result_rtl);
- if (tmpmode == BLKmode)
- {
- /* Find the smallest integer mode large enough to hold the
- entire structure and use that mode instead of BLKmode
- on the USE insn for the return register. */
- for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
- tmpmode != VOIDmode;
- tmpmode = GET_MODE_WIDER_MODE (tmpmode))
- /* Have we found a large enough mode? */
- if (GET_MODE_SIZE (tmpmode) >= bytes)
- break;
-
- /* A suitable mode should have been found. */
- gcc_assert (tmpmode != VOIDmode);
-
- PUT_MODE (result_rtl, tmpmode);
- }
-
- if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode))
- result_reg_mode = word_mode;