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From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/110751] RISC-V: Suport undefined value that allows VSETVL PASS use TA/MA
Date: Wed, 13 Sep 2023 09:38:05 +0000	[thread overview]
Message-ID: <bug-110751-4-rsj58Cwdzb@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-110751-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110751

--- Comment #34 from Richard Biener <rguenth at gcc dot gnu.org> ---
The ELSE value of type TYPE would be constructed like

 tree var = create_tmp_var (type);
 tree else_val = get_or_create_ssa_default_def (cfun, var);

I'm not sure const0_rtx is a good representation on RTL - how would
you distinguish that from a conditional operation on an integer vector
with else value zero?  Say for an integer division?

 for (i)
   if (f[i])
     y[i] = x[i] / z[i];
   else
     y[i] = 0;

we don't have a separate "else" value for elements cut off via 'len'
vs. elements cut off via 'mask'.

On RTL there are "special" RTXen used for this kind of stuff, like
(use:mode ..) or (clobber const0_rtx), but I'm the wrong person to
ask which one would be most appropriate for a general operand in
an otherwise generic instruction.  Maybe Richard has a guess.

  parent reply	other threads:[~2023-09-13  9:38 UTC|newest]

Thread overview: 47+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-07-20  9:03 [Bug target/110751] New: " xuli1 at eswincomputing dot com
2023-07-20  9:10 ` [Bug target/110751] " juzhe.zhong at rivai dot ai
2023-07-20  9:30 ` rguenth at gcc dot gnu.org
2023-07-20  9:37 ` rguenth at gcc dot gnu.org
2023-07-20  9:58 ` kito at gcc dot gnu.org
2023-07-20 11:28 ` rguenther at suse dot de
2023-07-20 11:43 ` juzhe.zhong at rivai dot ai
2023-07-20 12:00 ` juzhe.zhong at rivai dot ai
2023-07-20 12:35 ` rguenther at suse dot de
2023-07-20 12:42 ` juzhe.zhong at rivai dot ai
2023-07-20 12:45 ` rguenther at suse dot de
2023-07-20 12:50 ` juzhe.zhong at rivai dot ai
2023-07-20 12:56 ` rguenther at suse dot de
2023-07-20 13:29 ` rsandifo at gcc dot gnu.org
2023-07-20 13:32 ` rguenther at suse dot de
2023-07-20 22:03 ` juzhe.zhong at rivai dot ai
2023-07-21  1:53 ` xuli1 at eswincomputing dot com
2023-07-21  6:17 ` rguenth at gcc dot gnu.org
2023-07-21 12:47 ` rsandifo at gcc dot gnu.org
2023-07-21 12:53 ` rguenth at gcc dot gnu.org
2023-07-21 13:23 ` rsandifo at gcc dot gnu.org
2023-07-24  6:20 ` rguenther at suse dot de
2023-07-25  7:05 ` juzhe.zhong at rivai dot ai
2023-09-12 11:44 ` juzhe.zhong at rivai dot ai
2023-09-12 14:24 ` rsandifo at gcc dot gnu.org
2023-09-12 14:53 ` juzhe.zhong at rivai dot ai
2023-09-12 15:59 ` rsandifo at gcc dot gnu.org
2023-09-12 16:21 ` juzhe.zhong at rivai dot ai
2023-09-12 16:27 ` juzhe.zhong at rivai dot ai
2023-09-12 16:31 ` juzhe.zhong at rivai dot ai
2023-09-12 22:44 ` juzhe.zhong at rivai dot ai
2023-09-13  7:56 ` rguenth at gcc dot gnu.org
2023-09-13  8:34 ` juzhe.zhong at rivai dot ai
2023-09-13  8:39 ` juzhe.zhong at rivai dot ai
2023-09-13  9:38 ` rguenth at gcc dot gnu.org [this message]
2023-09-13  9:39 ` rguenth at gcc dot gnu.org
2023-09-13  9:48 ` juzhe.zhong at rivai dot ai
2023-09-13  9:48 ` juzhe.zhong at rivai dot ai
2023-09-13 10:15 ` rguenther at suse dot de
2023-09-13 22:39 ` rsandifo at gcc dot gnu.org
2023-09-14  8:53 ` juzhe.zhong at rivai dot ai
2023-09-14  9:15 ` richard.sandiford at arm dot com
2023-09-20 16:27 ` cvs-commit at gcc dot gnu.org
2023-09-21  9:13 ` cvs-commit at gcc dot gnu.org
2023-09-21  9:28 ` juzhe.zhong at rivai dot ai
2023-09-22  7:31 ` xuli1 at eswincomputing dot com
2023-09-22  7:33 ` xuli1 at eswincomputing dot com

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