From: Andrew Pinski <pinskia@gmail.com>
To: Tom de Vries <tom@codesourcery.com>
Cc: gcc-patches@gcc.gnu.org, Bernd Schmidt <bernds@codesourcery.com>
Subject: Re: new sign/zero extension elimination pass
Date: Thu, 28 Oct 2010 21:00:00 -0000 [thread overview]
Message-ID: <AANLkTi==BHdr3ZZNt_99tu4tbGWqz8xJQf1m4FkDMxz4@mail.gmail.com> (raw)
In-Reply-To: <AANLkTik3umTLD4-EFgpgemZZX0gNmhO+2qU_gr+EEyAc@mail.gmail.com>
[-- Attachment #1: Type: text/plain, Size: 672 bytes --]
On Thu, Oct 28, 2010 at 12:03 PM, Andrew Pinski <pinskia@gmail.com> wrote:
> On Mon, Oct 18, 2010 at 8:36 AM, Tom de Vries <tom@codesourcery.com> wrote:
>> I created a new sign/zero extension elimination pass.
>>
>> The motivating example for this pass is:
>
> In the above case fwprop could do the majority of the work. In fact
> it simplifies the (subreg (zero_extend (subreg))) into (subreg) but
> does not replace it. I think you could extend fwprop to the correct
> thing.
Something like the attached patch. I have not bootstrap/tested it yet
but it works for your simple example.
This allows us not to add another pass.
Thanks,
Andrew Pinski
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Index: fwprop.c
===================================================================
--- fwprop.c (revision 166031)
+++ fwprop.c (working copy)
@@ -543,8 +543,14 @@ propagate_rtx_1 (rtx *px, rtx old_rtx, r
valid_ops &= propagate_rtx_1 (&op0, old_rtx, new_rtx, flags);
if (op0 == XEXP (x, 0))
return true;
- tem = simplify_gen_subreg (mode, op0, GET_MODE (SUBREG_REG (x)),
- SUBREG_BYTE (x));
+ tem = simplify_subreg (mode, op0, GET_MODE (SUBREG_REG (x)),
+ SUBREG_BYTE (x));
+ if (!tem)
+ return false;
+ else if (GET_CODE (tem) == SUBREG && REG_P (SUBREG_REG (tem)))
+ valid_ops = true;
+ else if (REG_P (tem))
+ valid_ops = true;
}
break;
next prev parent reply other threads:[~2010-10-28 19:19 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-10-18 15:54 Tom de Vries
2010-10-18 16:03 ` Andrew Pinski
2010-10-18 16:59 ` Richard Guenther
2010-10-21 10:06 ` Tom de Vries
2010-10-21 10:44 ` Paolo Bonzini
2010-10-21 11:00 ` Paolo Bonzini
2010-10-21 17:21 ` Paolo Bonzini
2010-10-22 9:05 ` Tom de Vries
2010-10-22 9:24 ` Paolo Bonzini
2010-10-22 9:15 ` Eric Botcazou
2010-10-28 20:45 ` Tom de Vries
2010-10-29 2:11 ` Paolo Bonzini
2010-10-29 2:42 ` Paolo Bonzini
2010-10-31 19:30 ` Tom de Vries
2010-10-31 20:58 ` Joseph S. Myers
2010-10-31 21:11 ` Paolo Bonzini
2010-11-03 18:49 ` Eric Botcazou
2010-10-29 1:04 ` Paolo Bonzini
2010-10-29 1:33 ` Paolo Bonzini
2010-11-03 18:50 ` Eric Botcazou
2010-11-08 21:29 ` Tom de Vries
2010-11-08 22:11 ` Paolo Bonzini
2010-11-12 8:29 ` Tom de Vries
2010-11-13 10:41 ` Eric Botcazou
2012-07-11 10:31 ` Tom de Vries
2012-07-11 11:42 ` Jakub Jelinek
2012-07-11 13:01 ` Tom de Vries
2012-07-12 1:52 ` Kenneth Zadeck
[not found] ` <4FFE2ADF.2060806@naturalbridge.com>
[not found] ` <4FFE9346.2070806@mentor.com>
2012-07-12 9:21 ` Tom de Vries
2012-07-12 12:05 ` Kenneth Zadeck
2012-07-13 7:54 ` Tom de Vries
2012-07-13 11:39 ` Kenneth Zadeck
2012-07-13 12:58 ` Tom de Vries
2012-07-17 15:17 ` Kenneth Zadeck
2012-07-20 18:41 ` Tom de Vries
2012-08-20 13:40 ` Tom de Vries
2010-10-28 20:55 ` Andrew Pinski
2010-10-28 21:00 ` Andrew Pinski [this message]
2010-10-28 21:12 ` Tom de Vries
2010-10-28 22:58 ` Andrew Pinski
2010-10-29 15:06 ` Tom de Vries
2010-10-29 0:34 ` Paolo Bonzini
2010-11-08 21:32 ` Andrew Pinski
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