From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 2136) id 2E0AE385C40F; Mon, 3 Oct 2022 11:08:49 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 2E0AE385C40F DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1664795329; bh=sM0nbHTzPGKcA21sxbB2sBEwSMXeUl4eeB1j+p2MNIg=; h=From:To:Subject:Date:From; b=cpcOewnaaOtTrlZ9wqjHBnsBiyne1Tfa0POktjSagTZQpBxalwVnftSyzk6LDzfdG PX4P05OrDaio3vIZEXjEhifX0c/Sd4Nlf2+nxOMKAB8PHV3tGW4JBSuwTC73wSsBt2 i8evz9I3jWCE8EtKxeyRicda79PrWg653xzUf/Io= MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" From: Aldy Hernandez To: gcc-cvs@gcc.gnu.org Subject: [gcc r13-3027] Do not pessimize range in set_nonzero_bits. X-Act-Checkin: gcc X-Git-Author: Aldy Hernandez X-Git-Refname: refs/heads/master X-Git-Oldrev: 7f6f1f521fc12d4dbbdd0766d8fb7121d1e5ea8d X-Git-Newrev: c0129d6b2a5f2b3cfedd213d48c95581f75312aa Message-Id: <20221003110849.2E0AE385C40F@sourceware.org> Date: Mon, 3 Oct 2022 11:08:49 +0000 (GMT) List-Id: https://gcc.gnu.org/g:c0129d6b2a5f2b3cfedd213d48c95581f75312aa commit r13-3027-gc0129d6b2a5f2b3cfedd213d48c95581f75312aa Author: Aldy Hernandez Date: Sun Oct 2 10:46:47 2022 +0200 Do not pessimize range in set_nonzero_bits. Currently if we have a range of [0,0] and we set the nonzero bits to 1, the current code pessimizes the range to [0,1] because it assumes the range is [1,1] plus the possibility of 0. This fixes the oversight. gcc/ChangeLog: * value-range.cc (irange::set_nonzero_bits): Do not pessimize range. (range_tests_nonzero_bits): New test. Diff: --- gcc/value-range.cc | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/gcc/value-range.cc b/gcc/value-range.cc index e1066f4946e..6e196574de9 100644 --- a/gcc/value-range.cc +++ b/gcc/value-range.cc @@ -2934,6 +2934,14 @@ irange::set_nonzero_bits (const wide_int_ref &bits) // range immediately. if (wi::popcount (bits) == 1) { + // Make sure we don't pessimize the range. + tree tbits = wide_int_to_tree (type (), bits); + if (!contains_p (tbits)) + { + set_nonzero_bits (tbits); + return; + } + bool has_zero = contains_p (build_zero_cst (type ())); set (type (), bits, bits); if (has_zero) @@ -3628,6 +3636,11 @@ range_tests_nonzero_bits () r1.set_nonzero_bits (0xff); r0.union_ (r1); ASSERT_TRUE (r0.varying_p ()); + + // Test that setting a nonzero bit of 1 does not pessimize the range. + r0.set_zero (integer_type_node); + r0.set_nonzero_bits (1); + ASSERT_TRUE (r0.zero_p ()); } // Build an frange from string endpoints.