public inbox for gcc-patches@gcc.gnu.org
 help / color / mirror / Atom feed
From: Jakub Jelinek <jakub@redhat.com>
To: Aldy Hernandez <aldyh@redhat.com>
Cc: gcc-patches@gcc.gnu.org
Subject: [PATCH] Fix up foperator_abs::op1_range [PR107569]
Date: Wed, 9 Nov 2022 11:55:09 +0100	[thread overview]
Message-ID: <Y2uHDeXiivo401ni@tucnak> (raw)

Hi!

foperator_abs::op1_range works except for the NaN handling,
from:
[frange] double [-Inf, 1.79769313486231570814527423731704356798070567525844996599e+308 (0x0.fffffffffffff8p+1024)]
lhs it computes r
[frange] double [-1.79769313486231570814527423731704356798070567525844996599e+308 (-0x0.fffffffffffff8p+1024), 1.79769313486231570814527423731704356798070567525844996599e+308 (0x0.fffffffffffff8p+1024)] +-NAN
which is correct except for the +-NAN part.
For r before the final step it makes sure to add -NAN if there is +NAN
in the lhs range, but the final r.union_ makes it unconditional +-NAN,
because the frange ctor sets +-NAN.
So, I think we need to clear it (or have some set variant which
says not to set NAN).

This patch fixes that, but isn't enough to fix the PR, something in
the assumptions handling is still broken (and the PR has other parts).

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

2022-11-09  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/107569
	* range-op-float.cc (foperator_abs::op1_range): Clear NaNs
	from the negatives frange before unioning it into r.

--- gcc/range-op-float.cc.jj	2022-11-06 11:56:27.138137781 +0100
+++ gcc/range-op-float.cc	2022-11-08 18:13:18.026974667 +0100
@@ -1280,9 +1280,10 @@ foperator_abs::op1_range (frange &r, tre
     return true;
   // Then add the negative of each pair:
   // ABS(op1) = [5,20] would yield op1 => [-20,-5][5,20].
-  r.union_ (frange (type,
-		    real_value_negate (&positives.upper_bound ()),
-		    real_value_negate (&positives.lower_bound ())));
+  frange negatives (type, real_value_negate (&positives.upper_bound ()),
+		    real_value_negate (&positives.lower_bound ()));
+  negatives.clear_nan ();
+  r.union_ (negatives);
   return true;
 }
 

	Jakub


             reply	other threads:[~2022-11-09 10:55 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-11-09 10:55 Jakub Jelinek [this message]
2022-11-09 11:32 ` Aldy Hernandez

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=Y2uHDeXiivo401ni@tucnak \
    --to=jakub@redhat.com \
    --cc=aldyh@redhat.com \
    --cc=gcc-patches@gcc.gnu.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).