>>
>> 1) If -fira_loop_pressure is enabled, it reduces ~24% invariant motions in my
>tests. But it does not help on total code size. Seams there is issue to update
>the
>"regs_needed" after moving an invariant out of the loop (My benchmark logs
>show ~73% cases have more than one invariants moved)
On Tue, Jul 3, 2012 at 10:29 AM, Zhenqiang Chen wrote:
>>-Original Message-
>>From: Richard Guenther [mailto:richard.guent...@gmail.com]
>>Sent: 2012年6月28日 17:24
>>To: Zhenqiang Chen
>>Cc: gcc-patches@gcc.gnu.org
>>Subject: Re: [PATCH] Disable loop2_i
>-Original Message-
>From: Richard Guenther [mailto:richard.guent...@gmail.com]
>Sent: 2012年6月28日 17:24
>To: Zhenqiang Chen
>Cc: gcc-patches@gcc.gnu.org
>Subject: Re: [PATCH] Disable loop2_invariant for -Os
>
>On Thu, Jun 28, 2012 at 10:33 AM, Zhenqiang Chen
>w
On Thu, Jun 28, 2012 at 10:33 AM, Zhenqiang Chen wrote:
>>> diff --git a/gcc/loop-init.c b/gcc/loop-init.c index 03f8f61..5d8cf73
>>> 100644
>>> --- a/gcc/loop-init.c
>>> +++ b/gcc/loop-init.c
>>> @@ -273,6 +273,12 @@ struct rtl_opt_pass pass_rtl_loop_done =
>>> static bool
>>> gate_rtl_move_loo
>-Original Message-
>From: Steven Bosscher [mailto:stevenb@gmail.com]
>Sent: 2012年6月27日 16:54
>To: Zhenqiang Chen
>Cc: gcc-patches@gcc.gnu.org
>Subject: Re: [PATCH] Disable loop2_invariant for -Os
>
>On Wed, Jun 27, 2012 at 10:40 AM, Zhenqiang Chen
> wro
>> diff --git a/gcc/loop-init.c b/gcc/loop-init.c index 03f8f61..5d8cf73
>> 100644
>> --- a/gcc/loop-init.c
>> +++ b/gcc/loop-init.c
>> @@ -273,6 +273,12 @@ struct rtl_opt_pass pass_rtl_loop_done =
>> static bool
>> gate_rtl_move_loop_invariants (void)
>> {
>> + /* In general, invariant motion
On Wed, Jun 27, 2012 at 10:40 AM, Zhenqiang Chen wrote:
> Hi,
>
> In general, invariant motion itself can not reduce code size. But it will
> change the liverange of the invariant, which might lead to more spilling.
This may be true for ARM but it's not true in general. Sometimes
loop-invariant a
On Wed, Jun 27, 2012 at 10:40 AM, Zhenqiang Chen wrote:
> Hi,
>
> In general, invariant motion itself can not reduce code size.
It can expose CSE opportunities across loops though.
> But it will
> change the liverange of the invariant, which might lead to more spilling.
"might" - indeed. I won
