[v3,2/7] ifcvt: Allow constants for noce_convert_multiple.
Commit Message
This lifts the restriction of not allowing constants for
noce_convert_multiple. The code later checks if a valid sequence
is produced anyway.
---
gcc/ifcvt.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
Comments
On 12/6/2021 11:43 AM, Robin Dapp via Gcc-patches wrote:
> This lifts the restriction of not allowing constants for
> noce_convert_multiple. The code later checks if a valid sequence
> is produced anyway.
> ---
> gcc/ifcvt.c | 13 ++++++++-----
> 1 file changed, 8 insertions(+), 5 deletions(-)
Fine with a ChangeLog once the prereqs are approved.
jeff
Posting the ChangeLog before pushing.
--
gcc/ChangeLog:
* ifcvt.c (noce_convert_multiple_sets): Allow constants.
(bb_ok_for_noce_convert_multiple_sets): Likewise.
@@ -3282,7 +3282,9 @@ noce_convert_multiple_sets (struct noce_if_info *if_info)
we'll end up trying to emit r4:HI = cond ? (r1:SI) : (r3:HI).
Wrap the two cmove operands into subregs if appropriate to prevent
that. */
- if (GET_MODE (new_val) != GET_MODE (temp))
+
+ if (!CONSTANT_P (new_val)
+ && GET_MODE (new_val) != GET_MODE (temp))
{
machine_mode src_mode = GET_MODE (new_val);
machine_mode dst_mode = GET_MODE (temp);
@@ -3293,7 +3295,8 @@ noce_convert_multiple_sets (struct noce_if_info *if_info)
}
new_val = lowpart_subreg (dst_mode, new_val, src_mode);
}
- if (GET_MODE (old_val) != GET_MODE (temp))
+ if (!CONSTANT_P (old_val)
+ && GET_MODE (old_val) != GET_MODE (temp))
{
machine_mode src_mode = GET_MODE (old_val);
machine_mode dst_mode = GET_MODE (temp);
@@ -3435,9 +3438,9 @@ bb_ok_for_noce_convert_multiple_sets (basic_block test_bb)
if (!REG_P (dest))
return false;
- if (!(REG_P (src)
- || (GET_CODE (src) == SUBREG && REG_P (SUBREG_REG (src))
- && subreg_lowpart_p (src))))
+ if (!((REG_P (src) || CONSTANT_P (src))
+ || (GET_CODE (src) == SUBREG && REG_P (SUBREG_REG (src))
+ && subreg_lowpart_p (src))))
return false;
/* Destination must be appropriate for a conditional write. */