From: Aldy Hernandez <aldyh@redhat.com>
To: GCC patches <gcc-patches@gcc.gnu.org>
Cc: Richard Biener <richard.guenther@gmail.com>,
Jakub Jelinek <jakub@redhat.com>,
Andrew MacLeod <amacleod@redhat.com>,
Aldy Hernandez <aldyh@redhat.com>
Subject: [PATCH] [PR68097] frange::set_nonnegative should not contain -NAN.
Date: Mon, 19 Sep 2022 09:59:01 +0200 [thread overview]
Message-ID: <20220919075901.1798294-1-aldyh@redhat.com> (raw)
ISTM that a specifically nonnegative range should not contain -NAN,
otherwise signbit_p() would return false, because we'd be unsure of the
sign.
Do y'all agree?
PR 68097/tree-optimization
gcc/ChangeLog:
* value-range.cc (frange::set_nonnegative): Set +NAN.
(range_tests_signed_zeros): New test.
* value-range.h (frange::update_nan): New overload to set NAN sign.
---
gcc/value-range.cc | 9 +++++++++
gcc/value-range.h | 14 ++++++++++++++
2 files changed, 23 insertions(+)
diff --git a/gcc/value-range.cc b/gcc/value-range.cc
index 67d5d7fa90f..e432ec8b525 100644
--- a/gcc/value-range.cc
+++ b/gcc/value-range.cc
@@ -752,6 +752,10 @@ void
frange::set_nonnegative (tree type)
{
set (type, dconst0, dconstinf);
+
+ // Set +NAN as the only possibility.
+ if (HONOR_NANS (type))
+ update_nan (/*sign=*/0);
}
// Here we copy between any two irange's. The ranges can be legacy or
@@ -3800,6 +3804,11 @@ range_tests_signed_zeros ()
r1.update_nan ();
r0.intersect (r1);
ASSERT_TRUE (r0.known_isnan ());
+
+ r0.set_nonnegative (float_type_node);
+ ASSERT_TRUE (r0.signbit_p (signbit) && !signbit);
+ if (HONOR_NANS (float_type_node))
+ ASSERT_TRUE (r0.maybe_isnan ());
}
static void
diff --git a/gcc/value-range.h b/gcc/value-range.h
index 3a401f3e4e2..5b261d4f46a 100644
--- a/gcc/value-range.h
+++ b/gcc/value-range.h
@@ -312,6 +312,7 @@ public:
const REAL_VALUE_TYPE &lower_bound () const;
const REAL_VALUE_TYPE &upper_bound () const;
void update_nan ();
+ void update_nan (bool sign);
void clear_nan ();
// fpclassify like API
@@ -1098,6 +1099,19 @@ frange::update_nan ()
verify_range ();
}
+// Like above, but set the sign of the NAN.
+
+inline void
+frange::update_nan (bool sign)
+{
+ gcc_checking_assert (!undefined_p ());
+ m_pos_nan = !sign;
+ m_neg_nan = sign;
+ normalize_kind ();
+ if (flag_checking)
+ verify_range ();
+}
+
// Clear the NAN bit and adjust the range.
inline void
--
2.37.1
next reply other threads:[~2022-09-19 7:59 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-19 7:59 Aldy Hernandez [this message]
2022-09-19 8:14 ` Richard Biener
2022-09-19 12:51 ` Aldy Hernandez
2022-09-19 13:42 ` Richard Biener
2022-09-19 13:58 ` Michael Matz
2022-09-20 5:25 ` Aldy Hernandez
2022-09-20 12:51 ` Michael Matz
2022-09-20 14:58 ` Aldy Hernandez
2022-09-20 15:09 ` Jakub Jelinek
2022-09-20 18:08 ` Aldy Hernandez
2022-09-20 5:32 ` 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=20220919075901.1798294-1-aldyh@redhat.com \
--to=aldyh@redhat.com \
--cc=amacleod@redhat.com \
--cc=gcc-patches@gcc.gnu.org \
--cc=jakub@redhat.com \
--cc=richard.guenther@gmail.com \
/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).