rtx
gen_lowpart_general (machine_mode mode, rtx x)
{
rtx result = gen_lowpart_common (mode, x);
if (result)
return result;
/* Handle SUBREGs and hard REGs that were rejected by
simplify_gen_subreg. */
else if (REG_P (x) || GET_CODE (x) == SUBREG)
{
result = gen_lowpart_common (mode, copy_to_reg (x));
gcc_assert (result != 0);
return result;
}
else
{
/* The only additional case we can do is MEM. */
gcc_assert (MEM_P (x));
/* The following exposes the use of "x" to CSE. */
scalar_int_mode xmode;
if (is_a <scalar_int_mode> (GET_MODE (x), &xmode)
&& GET_MODE_SIZE (xmode) <= UNITS_PER_WORD
&& TRULY_NOOP_TRUNCATION_MODES_P (mode, xmode)
&& !reload_completed)
return gen_lowpart_general (mode, force_reg (xmode, x));
poly_int64 offset = byte_lowpart_offset (mode, GET_MODE (x));
return adjust_address (x, mode, offset);
}
}
rtx
gen_lowpart_general (machine_mode mode, rtx x)
{
rtx result = gen_lowpart_common (mode, x);
if (result)
return result;
/* Handle SUBREGs and hard REGs that were rejected by
simplify_gen_subreg. */
else if (REG_P (x) || GET_CODE (x) == SUBREG)
{
result = gen_lowpart_common (mode, copy_to_reg (x));
gcc_assert (result != 0);
return result;
}
else
{
int offset = 0;
/* The only additional case we can do is MEM. */
gcc_assert (MEM_P (x));
/* The following exposes the use of "x" to CSE. */
if (GET_MODE_SIZE (GET_MODE (x)) <= UNITS_PER_WORD
&& SCALAR_INT_MODE_P (GET_MODE (x))
&& TRULY_NOOP_TRUNCATION_MODES_P (mode, GET_MODE (x))
&& !reload_completed)
return gen_lowpart_general (mode, force_reg (GET_MODE (x), x));
if (WORDS_BIG_ENDIAN)
offset = (MAX (GET_MODE_SIZE (GET_MODE (x)), UNITS_PER_WORD)
- MAX (GET_MODE_SIZE (mode), UNITS_PER_WORD));
if (BYTES_BIG_ENDIAN)
/* Adjust the address so that the address-after-the-data
is unchanged. */
offset -= (MIN (UNITS_PER_WORD, GET_MODE_SIZE (mode))
- MIN (UNITS_PER_WORD, GET_MODE_SIZE (GET_MODE (x))));
return adjust_address (x, mode, offset);
}
}
static bool
get_best_extraction_insn (extraction_insn *insn,
enum extraction_pattern pattern,
enum extraction_type type,
unsigned HOST_WIDE_INT struct_bits,
machine_mode field_mode)
{
opt_scalar_int_mode mode_iter;
FOR_EACH_MODE_FROM (mode_iter, smallest_int_mode_for_size (struct_bits))
{
scalar_int_mode mode = mode_iter.require ();
if (get_extraction_insn (insn, pattern, type, mode))
{
FOR_EACH_MODE_FROM (mode_iter, mode)
{
mode = mode_iter.require ();
if (maybe_gt (GET_MODE_SIZE (mode), GET_MODE_SIZE (field_mode))
|| TRULY_NOOP_TRUNCATION_MODES_P (insn->field_mode,
field_mode))
break;
get_extraction_insn (insn, pattern, type, mode);
}
return true;
}
