Jeff,
Thanks a lot for your comments.
The widen shift mode is on i1/i2 before they're combined with i3 to newpat.
The newpat matches rotate/mask pattern. The i1/i2 itself don't match
rotate/mask pattern.
I did an experiment to disable widen shift mode for
lshiftrt. I tested it on
On 7/20/23 18:59, HAO CHEN GUI wrote:
Hi Jeff,
在 2023/7/21 5:27, Jeff Law 写道:
Wouldn't it make more sense to just try rotate/mask in the original mode before
trying a shift in a widened mode? I'm not sure why we need a target hook here.
There is no change to try rotate/mask with the
Sorry for the typo
s/change/chance
在 2023/7/21 8:59, HAO CHEN GUI 写道:
> Hi Jeff,
>
> 在 2023/7/21 5:27, Jeff Law 写道:
>> Wouldn't it make more sense to just try rotate/mask in the original mode
>> before trying a shift in a widened mode? I'm not sure why we need a target
>> hook here.
>
>
Hi Jeff,
在 2023/7/21 5:27, Jeff Law 写道:
> Wouldn't it make more sense to just try rotate/mask in the original mode
> before trying a shift in a widened mode? I'm not sure why we need a target
> hook here.
There is no change to try rotate/mask with the original mode when
On 7/18/23 21:06, HAO CHEN GUI via Gcc-patches wrote:
Hi,
The shift mode will be widen in combine pass if the operand has a normal
subreg. But when the target already has rotate/mask/insert instructions on
the narrow mode, it's unnecessary to widen the mode for lshiftrt. As
the lshiftrt is
Hi,
The shift mode will be widen in combine pass if the operand has a normal
subreg. But when the target already has rotate/mask/insert instructions on
the narrow mode, it's unnecessary to widen the mode for lshiftrt. As
the lshiftrt is commonly converted to rotate/mask insn, the widen mode
