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_if_possible (machine_mode mode, rtx x)
{
rtx result = gen_lowpart_common (mode, x);
if (result)
return result;
else if (MEM_P (x))
{
/* This is the only other case we handle. */
poly_int64 offset = byte_lowpart_offset (mode, GET_MODE (x));
rtx new_rtx = adjust_address_nv (x, mode, offset);
if (! memory_address_addr_space_p (mode, XEXP (new_rtx, 0),
MEM_ADDR_SPACE (x)))
return 0;
return new_rtx;
}
else if (mode != GET_MODE (x) && GET_MODE (x) != VOIDmode
&& validate_subreg (mode, GET_MODE (x), x,
subreg_lowpart_offset (mode, GET_MODE (x))))
return gen_lowpart_SUBREG (mode, x);
else
return 0;
}
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);
}
}
rtx
gen_lowpart_general (enum machine_mode mode, rtx x)
{
rtx result = gen_lowpart_common (mode, x);
if (result)
return result;
else if (REG_P (x))
{
/* Must be a hard reg that's not valid in MODE. */
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 (GET_MODE_BITSIZE (mode),
GET_MODE_BITSIZE (GET_MODE (x)))
&& ! no_new_pseudos)
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);
}
}
