From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 2136) id 0FBAD3858406; Tue, 20 Sep 2022 05:22:24 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 0FBAD3858406 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1663651344; bh=yn4yJ6KdWdf6WIkcU3l7eT8jRo3oFNiK6vWO9/D7akA=; h=From:To:Subject:Date:From; b=HBARjhxtH/ZtJBlvlGOTMIWwhmjtBwLCDNU4j3myLcbycVUQDwffp7EYg7ZDDNI/F sLD7ttNOzVac/xIQrXmfc/vNG9v0EegP61R47EtztsnupCy9uQwGMIG0lKFDOnXK83 fN2LW3pMe/OxSmOUzRftu9tH/L2eoMnfBK+c4/SA= 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 r13-2727] frange: flush denormals to zero X-Act-Checkin: gcc X-Git-Author: Aldy Hernandez X-Git-Refname: refs/heads/master X-Git-Oldrev: 041812f584a1c82f1255bd96f3503493bd9fb127 X-Git-Newrev: 2b61ed838c7f3f4bf54d4530c0f053b420623beb Message-Id: <20220920052224.0FBAD3858406@sourceware.org> Date: Tue, 20 Sep 2022 05:22:24 +0000 (GMT) List-Id: https://gcc.gnu.org/g:2b61ed838c7f3f4bf54d4530c0f053b420623beb commit r13-2727-g2b61ed838c7f3f4bf54d4530c0f053b420623beb Author: Aldy Hernandez Date: Sat Sep 17 10:17:13 2022 +0200 frange: flush denormals to zero For some architectures (or for -funsafe-math-optimizations) we may flush denormals to zero, in which case we need to be careful to extend the ranges to the appropriate zero. This patch does exactly that. For a range of [x, -DENORMAL] we flush to [x, -0.0] and for [+DENORMAL, x] we flush to [+0.0, x]. gcc/ChangeLog: * value-range.cc (frange::flush_denormals_to_zero): New. (frange::set): Call flush_denormals_to_zero. * value-range.h (class frange): Add flush_denormals_to_zero. Diff: --- gcc/value-range.cc | 23 +++++++++++++++++++++++ gcc/value-range.h | 1 + 2 files changed, 24 insertions(+) diff --git a/gcc/value-range.cc b/gcc/value-range.cc index 67d5d7fa90f..a8e3bb39bab 100644 --- a/gcc/value-range.cc +++ b/gcc/value-range.cc @@ -267,6 +267,26 @@ tree_compare (tree_code code, tree op1, tree op2) return !integer_zerop (fold_build2 (code, integer_type_node, op1, op2)); } +// Flush denormal endpoints to the appropriate 0.0. + +void +frange::flush_denormals_to_zero () +{ + if (undefined_p () || known_isnan ()) + return; + + // Flush [x, -DENORMAL] to [x, -0.0]. + if (real_isdenormal (&m_max) && real_isneg (&m_max)) + { + m_max = dconst0; + if (HONOR_SIGNED_ZEROS (m_type)) + m_max.sign = 1; + } + // Flush [+DENORMAL, x] to [+0.0, x]. + if (real_isdenormal (&m_min) && !real_isneg (&m_min)) + m_min = dconst0; +} + // Setter for franges. void @@ -317,6 +337,9 @@ frange::set (tree min, tree max, value_range_kind kind) gcc_checking_assert (tree_compare (LE_EXPR, min, max)); normalize_kind (); + + flush_denormals_to_zero (); + if (flag_checking) verify_range (); } diff --git a/gcc/value-range.h b/gcc/value-range.h index 3a401f3e4e2..795b1f00fdc 100644 --- a/gcc/value-range.h +++ b/gcc/value-range.h @@ -327,6 +327,7 @@ private: bool union_nans (const frange &); bool intersect_nans (const frange &); bool combine_zeros (const frange &, bool union_p); + void flush_denormals_to_zero (); tree m_type; REAL_VALUE_TYPE m_min;